2024-03-29T01:23:59Zhttps://upcommons.upc.edu/oai/requestoai:upcommons.upc.edu:2117/1930472020-07-26T18:09:43Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
García, Alberto
Papior, Nick
Akhtar, Arsalan
Artacho, Emilio
Blum, Volker
Bosoni, Emanuele
Brandimarte, Pedro
Brandbyge, Mads
Cerdá, Jorge I.
Corsetti, Fabiano
Cuadrado, Ramón
Dikan, Vladimir
Ferrer, Jaime
Gale, Julian
García Fernández, Pablo
García Suárez, Víctor Manuel
García, Sandra
Huhs, Georg
Illera, Sergio
Korytár, Richard
Koval, Peter
Lebedeva, Irina
Lin, Lin
López Tarifa, Pablo
Mayo, Sara G.
Mohr, Stephan
Ordejón, Pablo
Postnikov, Andrei
Pouillon, Yann
Pruneda, Miguel
Robles, Roberto
Sánchez Portal, Daniel
Soler, Jose M.
Ullah, Raffi
Wen-zhe Yu, Víctor
Junquera, Javier
Barcelona Supercomputing Center
2020-07-16T14:21:00Z
2020-07-16T14:21:00Z
2020
García, A. [et al.]. Siesta: Recent developments and applications. "The Journal of Chemical Physics", 2020, vol. 152, núm. 20.
1089-7690
http://hdl.handle.net/2117/193047
10.1063/5.0005077
A review of the present status, recent enhancements, and applicability of the Siesta program is presented. Since its debut in the mid-1990s, Siesta's flexibility, efficiency, and free distribution have given advanced materials simulation capabilities to many groups worldwide. The core methodological scheme of Siesta combines finite-support pseudo-atomic orbitals as basis sets, norm-conserving pseudopotentials, and a real-space grid for the representation of charge density and potentials and the computation of their associated matrix elements. Here, we describe the more recent implementations on top of that core scheme, which include full spin-orbit interaction, non-repeated and multiple-contact ballistic electron transport, density functional theory (DFT)+U and hybrid functionals, time-dependent DFT, novel reduced-scaling solvers, density-functional perturbation theory, efficient van der Waals non-local density functionals, and enhanced molecular-dynamics options. In addition, a substantial effort has been made in enhancing interoperability and interfacing with other codes and utilities, such as wannier90 and the second-principles modeling it can be used for, an AiiDA plugin for workflow automatization, interface to Lua for steering Siesta runs, and various post-processing utilities. Siesta has also been engaged in the Electronic Structure Library effort from its inception, which has allowed the sharing of various low-level libraries, as well as data standards and support for them, particularly the PSeudopotential Markup Language definition and library for transferable pseudopotentials, and the interface to the ELectronic Structure Infrastructure library of solvers. Code sharing is made easier by the new open-source licensing model of the program. This review also presents examples of application of the capabilities of the code, as well as a view of on-going and future developments.
SIESTA development has been historically supported by different Spanish National Plan projects: MEC-DGESPB95-0202, MCyT-BFM2000-1312, MEC-BFM2003-03372,FIS2006-12117, FIS2009-12721, FIS2012-37549, FIS2015-
64886-P, and RTC-2016-5681-7, the latter one together with Simune Atomistics Ltd. Currently, we thank financial support from the Spanish Ministry of Science, Innovation and Universities through the grant No. PGC2018-096955-B.
We acknowledge the Severo Ochoa Centers of Excellence Program under Grants No. SEV-2015-0496 (ICMAB), and SEV-2017-0706 (ICN2), the GenCat Grant No.2017SGR1506, and the European Union MaX Center of Excellence (EU-H2020 Grant No. 824143). P.G.-F. acknowledges support from Ramón y Cajal Grant No. RyC-2013-12515. J.I.C acknowledges RTI2018-097895-B-C41. R.C. acknowledges to the European Union’s Horizon 2020 research and innovation program under the Marie Skłodoswka–Curie grant agreement no. 665919. D.S.P, P.K, and P.B acknowledge MAT2016-78293-C6, FET-Open No. 863098, and UPV-EHU Grant IT1246-19. V. Yu was supported by a MolSSI fellowship (U.S. NSF award 1547580), and the ELSI development (V.B.,V.Yu) by NSF award 1450280. We also acknowledge Honghui Shang and Xinming Qin for giving us access to the HONPAS code, where a preliminary version of the hybrid functionals support described here was implemented. We are indebted to other contributors to the SIESTA
project, whose names can be seen in the file in the Docs/Contributors.txt file of the SIESTA distribution, and we thank those, too many to list, contributing fixes, comments, clarifications, and documentation for the code. The data that support the findings of this study are available from the corresponding author upon reasonable request.
Peer Reviewed
Postprint (author's final draft)
29 p.
eng
AIP Publishing
Àrees temàtiques de la UPC::Informàtica::Aplicacions de la informàtica
Molecular dynamics
Mathematical models
Electron transport
Matrix analytic methods
Pseudopotential method
SIESTA
Charge density
Density functional theory (DFT)+U
Electronic Structure Library
Electron transport
Molecular dynamics
PSeudopotential Markup Language
Dinàmica molecular
Models matemàtics
Siesta: Recent developments and applications
Article
https://aip.scitation.org/doi/10.1063/5.0005077
info:eu-repo/grantAgreement/EC/H2020/824143/EU/MAterials design at the eXascale. European Centre of Excellence in materials modelling, simulations, and design/MaX
Open Access
The Journal of Chemical Physics
152
20
eprints
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/1108682020-07-23T23:27:41Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Kiptily, V.G.
Fitzgerald, M.
Goloborodko, V.
Sharapov, S.E.
Challis, C.D.
Frigione, D.
Graves, J.
Mantsinen, Mervi
Beaumont, P.
Garcia-Munoz, M.
Perez von Thun, C.
Rodriguez, J.F.R.
Darrow, D.
Keeling, D.
King, D.
McClements, K.G.
Solano, E.R.
Schmuck, S.
Sips, G.
Szepesi, G.
JET Contributors
Barcelona Supercomputing Center
2017-11-17T15:09:12Z
2018-12-01T01:31:00Z
2018
Kiptily, V.G. [et al.]. Fusion product losses due to fishbone instabilities in deuterium JET plasmas. "Nuclear Fusion", 2018, vol. 58, núm. 1.
0029-5515
http://hdl.handle.net/2117/110868
10.1088/1741-4326/aa9340
During development of a high-performance hybrid scenario for future deuterium–tritium experiments on the Joint European Torus, an increased level of fast ion losses in the MeV energy range was observed during the instability of high-frequency n = 1 fishbones. The fishbones are excited during deuterium neutral beam injection combined with ion cyclotron heating. The frequency range of the fishbones, 10–25 kHz, indicates that they are driven by a resonant interaction with the NBI-produced deuterium beam ions in the energy range ≤120 keV. The fast particle losses in a much higher energy range are measured with a fast ion loss detector, and the data show an expulsion of deuterium plasma fusion products, 1 MeV tritons and 3 MeV protons, during the fishbone bursts. An MHD mode analysis with the MISHKA code combined with the nonlinear wave-particle interaction code HAGIS shows that the loss of toroidal symmetry caused by the n = 1 fishbones affects strongly the confinement of non-resonant high energy fusion-born tritons and protons by perturbing their orbits and expelling them. This modelling is in a good agreement with the experimental data.
This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014-2018 under grant agreement No 633053 and from the RCUK Energy Programme [grant No EP/P012450/1]. To obtain further information on the data and models underlying this paper please contact PublicationsManager@ukaea.uk . The views and opinions expressed herein do not necessarily reflect those of the European Commission
Peer Reviewed
Postprint (author's final draft)
eng
IOP Publishing
Attribution-NonCommercial-NoDerivs 3.0 Spain
http://creativecommons.org/licenses/by-nc-nd/3.0/es/
Open Access
Àrees temàtiques de la UPC::Física
Fusion reactions
Plasma dynamics
Fusion
JET plasmas
MHD
Cyclotron heating
Fusió nuclear controlada
Tècniques de plasma
Fusion product losses due to fishbone instabilities in deuterium JET plasmas
Article
http://iopscience.iop.org/article/10.1088/1741-4326/aa9340
info:eu-repo/grantAgreement/EC/H2020/633053/EU/Implementation of activities described in the Roadmap to Fusion during Horizon 2020 through a Joint programme of the members of the EUROfusion consortium/EUROfusion
Nuclear Fusion
58
1
014003
eprints
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/965432022-05-17T19:45:53Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523oai:upcommons.upc.edu:2117/862732022-05-17T10:08:35Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Escolar, Soledad
Carretero, Jesús
Marinescu, Maria-Cristina
Chessa, Stefano
Barcelona Supercomputing Center
2016-04-27T14:37:45Z
2016-04-27T14:37:45Z
2014-05-08
Escolar, Soledad [et al.]. Estimating Energy Savings in Smart Street Lighting by Using an Adaptive Control System. "International Journal of Distributed Sensor Networks", 08 Maig 2014, vol. 2014, ID 971587.
1550-1329
http://hdl.handle.net/2117/86273
10.1155/2014/971587
The driving force behind the smart city initiative is to offer better, more specialized services which can improve the quality of life of the citizens while promoting sustainability. To achieve both of these apparently competing goals, services must be increasingly autonomous and continuously adaptive to changes in their environment and the information coming from other services. In this paper we focus on smart lighting, a relevant application domain for which we propose an intelligent street light control system based on adaptive behavior rules. We evaluate our approach by using a simulator which combines wireless sensor networks and belief-desire-intention (BDI) agents to enable a precise simulation of both the city infrastructure and the adaptive behavior that it implements.The results reveal energy savings of close to 35% when the lighting systemimplements an adaptive behavior as opposed to a rigid, predefined behavior.
Thiswork has been funded by the Spanish Ministry of Science and Technology under the Grant TIN2010-16497 “Técnicas
Escalables de E/S en Entornos Distribuidos y de Computación de Altas Prestaciones.”
Peer Reviewed
Postprint (published version)
17 p.
eng
Hindawi Publishing Corporation
Attribution-NonCommercial-NoDerivs 3.0 Spain
http://creativecommons.org/licenses/by-nc-nd/3.0/es/
Open Access
Àrees temàtiques de la UPC::Enginyeria electrònica
Street lighting
Simulation methods
IERC
Smart city
Energy saving
Lighting system
Enllumenat--Aspectes ambientals
Simulació, Mètodes de
Estimating Energy Savings in Smart Street Lighting by Using an Adaptive Control System
Article
http://www.hindawi.com/journals/ijdsn/2014/971587/
info:eu-repo/grantAgreement/MICINN//TIN2010-16497/ES/TECNICAS ESCALABLES DE ENTRADA%2FSALIDA EN ENTORNOS DISTRIBUIDOS Y DE COMPUTACION DE ALTAS PRESTACIONES/
ID 971587
International Journal of Distributed Sensor Networks
2014
eprints
10.13039/501100004837
Ministerio de Ciencia e Innovación
oai:upcommons.upc.edu:2117/3420842021-03-21T19:31:11Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Kazakov, Ye. O.
Ongena, Jozef
Wright, John
Wukitch, Stephen J.
Bobkov, Volodymyr
Mantsinen, Mervi
Gallart, Daniel
Barcelona Supercomputing Center
2021-03-19T14:23:49Z
2021-03-19T14:23:49Z
2021
Kazakov, Y.O. [et al.]. Physics and applications of three-ion ICRF scenarios for fusion research. "Physics of Plasmas", 2021, vol. 28, núm. 2.
1089-7674
http://hdl.handle.net/2117/342084
10.1063/5.0021818
This paper summarizes the physical principles behind the novel three-ion scenarios using radio frequency waves in the ion cyclotron range of frequencies (ICRF). We discuss how to transform mode conversion electron heating into a new flexible ICRF technique for ion cyclotron heating and fast-ion generation in multi-ion species plasmas. The theoretical section provides practical recipes for selecting the plasma composition to realize three-ion ICRF scenarios, including two equivalent possibilities for the choice of resonant absorbers that have been identified. The theoretical findings have been convincingly confirmed by the proof-of-principle experiments in mixed H?D plasmas on the Alcator C-Mod and JET tokamaks, using thermal 3He and fast D ions from neutral beam injection as resonant absorbers. Since 2018, significant progress has been made on the ASDEX Upgrade and JET tokamaks in H?4He and H?D plasmas, guided by the ITER needs. Furthermore, the scenario was also successfully applied in JET D?3He plasmas as a technique to generate fusion-born alpha particles and study effects of fast ions on plasma confinement under ITER-relevant plasma heating conditions. Tuned for the central deposition of ICRF power in a small region in the plasma core of large devices such as JET, three-ion ICRF scenarios are efficient in generating large populations of passing fast ions and modifying the q-profile. Recent experimental and modeling developments have expanded the use of three-ion scenarios from dedicated ICRF studies to a flexible tool with a broad range of different applications in fusion research.
AB - This paper summarizes the physical principles behind the novel three-ion scenarios using radio frequency waves in the ion cyclotron range of frequencies (ICRF). We discuss how to transform mode conversion electron heating into a new flexible ICRF technique for ion cyclotron heating and fast-ion generation in multi-ion species plasmas. The theoretical section provides practical recipes for selecting the plasma composition to realize three-ion ICRF scenarios, including two equivalent possibilities for the choice of resonant absorbers that have been identified. The theoretical findings have been convincingly confirmed by the proof-of-principle experiments in mixed H?D plasmas on the Alcator C-Mod and JET tokamaks, using thermal 3He and fast D ions from neutral beam injection as resonant absorbers. Since 2018, significant progress has been made on the ASDEX Upgrade and JET tokamaks in H?4He and H?D plasmas, guided by the ITER needs. Furthermore, the scenario was also successfully applied in JET D?3He plasmas as a technique to generate fusion-born alpha particles and study effects of fast ions on plasma confinement under ITER-relevant plasma heating conditions. Tuned for the central deposition of ICRF power in a small region in the plasma core of large devices such as JET, three-ion ICRF scenarios are efficient in generating large populations of passing fast ions and modifying the q-profile. Recent experimental and modeling developments have expanded the use of three-ion scenarios from dedicated ICRF studies to a flexible tool with a broad range of different applications in fusion research.
The authors are grateful to the anonymous reviewers for their constructive comments that allowed us to improve the paper, I. Voitsekhovitch for her valuable comments and suggestions during the paper preparation, and to H. Meyer and J. Faustin for fruitful discussions. We thank the ITPA Energetic Particle Physics Topical Group for its support. This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014–2018 and 2019–2020 under Grant Agreement No. 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. Part of this work was also carried out in the framework of projects done for the ITER Scientist Fellow Network (ISFN).
ITER is the Nuclear Facility INB No. 174. The views and opinions expressed herein do not necessarily reflect those of the ITER Organization. This publication is provided for scientific purposes only. Its contents should not be considered as commitments from the ITER Organization as a nuclear operator in the frame of the licensing process.
Peer Reviewed
Postprint (published version)
"Article signat per 67 autors/es: Ye. O. Kazakov, J. Ongena, J. C. Wright, S. J. Wukitch, V. Bobkov, J. Garcia, V. G. Kiptily, M. J. Mantsinen, M. Nocente, M. Schneider, H. Weisen, Y. Baranov, M. Baruzzo, R. Bilato, A. Chomiczewska, R. Coelho, T. Craciunescu K. Crombé, M. Dreval, R. Dumont, P. Dumortier, F. Durodié, J. Eriksson, M. Fitzgerald, J. Galdon-Quiroga, D. Gallart, M. Garcia-Muñoz, L. Giacomelli, C. Giroud, J. Gonzalez-Martin, A. Hakola, P. Jacquet, T. Johnson, A. Kappatou, D. Keeling, D. King, K. K. Kirov, P. Lamalle, M. Lennholm, E. Lerche, M. Maslov, S. Mazzi, S. Menmuir, I. Monakhov5, F. Nabais, M. F. F. Nave, R. Ochoukov, A. R. Polevoi, S. D. Pinches, U. Plank, D. Rigamonti, M. Salewski, P. A. Schneider, S. E. Sharapov, Ž. Štancar, A. Thorman, D. Valcarcel, D. Van Eester, M. Van Schoor, J. Varje, M. Weiland, N. Wendler, JET Contributors, ASDEX Upgrade Team, EUROfusion MST1 Team, and Alcator C-Mod Team"
22 p.
eng
American Institute of Physics
Attribution 3.0 Spain
Attribution 4.0 International (CC BY 4.0)
http://creativecommons.org/licenses/by/3.0/es/
https://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Física
Nuclear fusion
Plasma waves
Plasma heating
Fusion
Three-ion ICRF
ICRF
Plasma waves
Fusió nuclear
Physics and applications of three-ion ICRF scenarios for fusion research
Article
https://aip.scitation.org/doi/10.1063/5.0021818
info:eu-repo/grantAgreement/EC/H2020/633053/EU/Implementation of activities described in the Roadmap to Fusion during Horizon 2020 through a Joint programme of the members of the EUROfusion consortium/EUROfusion
Physics of Plasmas
28
2
eprints
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3811142023-01-29T18:44:06Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523
Guillamet, Gerard
Quintanas Corominas, Adrià
Rivero, Matías
Houzeaux, Guillaume
Vázquez, Mariano
Turon, Albert
Barcelona Supercomputing Center
2023-01-25T11:04:01Z
2023
2025-01-06
Guillamet, G. [et al.]. Application of the partial Dirichlet–Neumann contact algorithm to simulate low-velocity impact events on composite structures. "Composites Part A: Applied Science and Manufacturing", 2023, vol. 167, 107424.
1359-835X
http://arxiv.org/abs/2301.05552
http://hdl.handle.net/2117/381114
10.1016/j.compositesa.2022.107424
Impact simulations for damage resistance analysis are computationally intensive due to contact algorithms and advanced damage models. Both methods, which are the main ingredients in an impact event, require refined meshes at the contact zone to obtain accurate predictions of the contact force and damage onset and propagation through the material. This work presents the application of the partial Dirichlet–Neumann contact algorithm to simulate low-velocity impact problems on composite structures using High-Performance Computing. This algorithm is devised for parallel finite element codes running on supercomputers, and it is extended to explicit time integration schemes to solve impact problems including damage. The proposed framework is validated with a standard test for damage resistance on fiber-reinforced polymer matrix composites. Moreover, the parallel performance of the proposed algorithm has been evaluated in a mesh of 74M of elements running with 2400 processors
This work has received funding from the Clean Sky 2 Joint Undertaking (JU) under grant agreements No. 807083 and No. 945521 (SHERLOC project). The JU receives support from the European Union’s Horizon 2020 research and innovation program and the Clean Sky 2 JU members other than the Union. The authors gratefully acknowledge Hellenic Aerospace Industry for manufacturing of the coupons made of T800S/M21 material and Kirsa Muñoz and Miguel Ángel Jiménez from Element Materials Technology Seville
Peer Reviewed
Postprint (author's final draft)
eng
Elsevier
Attribution-NonCommercial-NoDerivatives 4.0 International
http://creativecommons.org/licenses/by-nc-nd/4.0/
Restricted access - publisher's policy
Àrees temàtiques de la UPC::Informàtica::Aplicacions de la informàtica::Aplicacions informàtiques a la física i l‘enginyeria
High performance computing
Airplanes
Contact mechanics
Damage modeling
Finite element analysis
High-performance computing
Simulació per ordinador
Application of the partial Dirichlet–Neumann contact algorithm to simulate low-velocity impact events on composite structures
Article
https://www.sciencedirect.com/science/article/pii/S1359835X22006054
info:eu-repo/grantAgreement/EC/H2020/807083/EU/AIRFRAME ITD/GAM AIR 2018
info:eu-repo/grantAgreement/EC/H2020/945521/EU/AIRFRAME ITD/GAM-2020-AIR
107424
Composites Part A: Applied Science and Manufacturing
167
eprints
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3836812023-02-17T15:20:11Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Kumar, Vishal
Miró, Arnau
Lehmkuhl Barba, Oriol
Piomelli, Ugo
Barcelona Supercomputing Center
2023-02-17T15:14:36Z
2023-02-17T15:14:36Z
2023
Kumar, V. [et al.]. Flow Separation in Airfoils with Rough Leading Edges. "AIAA Journal", 2023,
1533-385X
http://hdl.handle.net/2117/383681
10.2514/1.J062427
In this study we consider the flow over airfoils with leading-edge roughness, designed to mimic the ice depositions that may occur on an aircraft in flight. The focus of this investigation is the effect of the angle of attack on the mean-flow three-dimensionality. In our previous work (Kumar et al., Journal of Turbulence, Vol. 22, No. 11, 2021, pp. 735–760), we found stationary spanwise inhomogeneities in the form of alternating regions of fast- and slow-moving fluid, which were termed “flow channels.” In the present study we investigate further this phenomenon. We observe the formation of hairpin vortices downstream of the roughness elements, which eventually merge; this causes the formation of wider channels that remain coherent and affect the trailing-edge separation. With increasing angle of attack, the intensity of flow channeling can increase or decrease depending on the topology of the leading-edge roughness. Its effect on the trailing-edge separation remains, however, significant. The mean-separation line is highly distorted, and the separation length can vary by up to 30% of the chord length along the span.
Peer Reviewed
Postprint (author's final draft)
eng
American Institute of Aeronautics and Astronautics
Àrees temàtiques de la UPC::Informàtica::Aplicacions de la informàtica::Aplicacions informàtiques a la física i l‘enginyeria
Airfoils
Turbulence
Airfoils
Aircraft
Ice-accretion
Simulació per ordinador
Flow Separation in Airfoils with Rough Leading Edges
Article
https://arc.aiaa.org/doi/abs/10.2514/1.J062427
Open Access
AIAA Journal
eprints
oai:upcommons.upc.edu:2117/975282020-10-11T00:56:35Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Gargallo-Peiró, Abel
Folch, Arnau
Roca, Xevi
Barcelona Supercomputing Center
2016-11-30T14:40:53Z
2016-11-30T14:40:53Z
2016
Gargallo-Peiró, Abel; Folch, Arnau; Roca, Xevi. Representing Urban Geometries for Unstructured Mesh Generation. "Procedia Engineering", 2016, vol. 163, p. 175-185.
1877-7058
http://hdl.handle.net/2117/97528
10.1016/j.proeng.2016.11.044
We present a robust and automatic method to generate an idealized surface geometry of a city landscape ready to be meshed for computer simulations. The city geometry is idealized for non viscous flow simulations and targets two main geometrical features: the topography and the city blocks. The procedure is fully automatic and demands no human interaction given the following source data: the city cadastre, a Digital Elevation Model (DEM) of all the target domain, and Light Detection And Ranging (LiDAR) data of the domain region covered by the cadastre. The geometry representation takes three main steps. First, a 2D mesh of the cadastre is generated, where the elements are marked according to street and block regions. Second, using a DEM of the city landscape the topography surface mesh is generated by finding the best surface mesh in the least-squares sense obtained by deforming the previous 2D mesh. Third, we extrude the block facades and we compute a planar ceiling taking into account all the buildings belonging to that city block. We describe the applicability of the geometry representation by presenting the work-flow required to generate an unstructured mesh valid for non-viscous flow or transport simulations. Finally, we illustrate the main application by obtaining a surface and tetrahedral mesh for the city of Barcelona in Spain.
This work has been developed in the context of the EU H2020 GrowSmarter project which has Barcelona as one of the three lighthouse cities. The work of the last author was supported by the European Commission through the Marie Sklodowska-Curie Actions (HiPerMeGaFlows project).
Peer Reviewed
Postprint (published version)
11 p.
eng
Elsevier
Attribution-NonCommercial-NoDerivs 4.0 International License
https://creativecommons.org/licenses/by-nc-nd/4.0/
Open Access
Àrees temàtiques de la UPC::Enginyeria biomèdica
Geometry--Data processing
Computer simulation
Surface mesh generation
Unstructured mesh generation
Mesh for simulation
Urban area mesh
Microscale CFD
Geometria computacional
Simulació per ordinador
Representing Urban Geometries for Unstructured Mesh Generation
Article
http://www.sciencedirect.com/science/article/pii/S1877705816333495
info:eu-repo/grantAgreement/EC/H2020/658853/EU/High-Performance Curved Meshing and Unstructured High-Order Galerkin Solvers for High-Fidelity Flow Simulation/HiPerMeGaFlowS
info:eu-repo/grantAgreement/EC/H2020/646456/EU/GrowSmarter/GrowSmarter
Procedia Engineering
163
175
185
eprints
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/1068822020-10-11T01:03:35Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Avila, Matias
Gargallo-Peiró, Abel
Folch, Arnau
Barcelona Supercomputing Center
2017-07-26T14:56:22Z
2017-07-26T14:56:22Z
2017
Avila, M.; Gargallo-Peiró, A.; Folch, A. A CFD framework for offshore and onshore wind farm simulation. "Journal of Physics: Conference Series", 2017, vol. 854, núm. 1.
1742-6588
http://hdl.handle.net/2117/106882
10.1088/1742-6596/854/1/012002
We present a wind simulation framework for offshore and onshore wind farms. The simulation framework involves an automatic hybrid high-quality mesh generation process, a pre-processing to impose initial and boundary conditions, and a solver for the Reynolds Averaged Navier-Stokes (RANS) equations with two different turbulence models, a modified standard k-epsilon model and a realizable k-epsilon model in which we included the Coriolis effects. Wind turbines are modeled as actuator discs. The wind farm simulation framework has been implemented in Alya, an in-house High Performance Computing (HPC) multi-physics finite element parallel solver. An application example is shown for an onshore wind farm composed of 165 turbines.
This work has been supported by the EU H2020 projects New European Wind Atlas ERA-NET PLUS (NEWA), High Performance Computing for Energy (HPC4E, grant agreement 689772), and the Energy oriented Centre of Excellence (EoCoE, grant agreement 676629). We also thank two anonymous reviewers for their constructive comments on the first version of the manuscript.
Peer Reviewed
Postprint (published version)
10 p.
eng
IOP Publishing
Attribution-NonCommercial-NoDerivs 3.0 Spain
http://creativecommons.org/licenses/by-nc-nd/3.0/es/
Open Access
Àrees temàtiques de la UPC::Energies
Wind energy
Forecasting--Computer simulation
Turbines
Reynolds Averaged Navier-Stokes (RANS)
High Performance Computing (HPC)
Wind simulation framework
Vent--Energia
Simulació per ordinador
A CFD framework for offshore and onshore wind farm simulation
Article
http://iopscience.iop.org/article/10.1088/1742-6596/854/1/012002/meta
info:eu-repo/grantAgreement/EC/H2020/689772/EU/HPC for Energy/HPC4E
info:eu-repo/grantAgreement/EC/H2020/676629/EU/Energy oriented Centre of Excellence for computer applications/EoCoE
Journal of Physics: Conference Series
854
1
012002
eprints
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3647792022-03-27T15:51:59Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Folch, Arnau
Mingari, Leonardo
Prata, Andrew T.
Barcelona Supercomputing Center
2022-03-23T16:31:11Z
2022-03-23T16:31:11Z
2022-01
Folch, A.; Mingari, L.; Prata, A.T. Ensemble-based forecast of volcanic clouds using FALL3D-8.1. "Frontiers in Earth Science", 2022, vol. 9.
2296-6463
http://hdl.handle.net/2117/364779
10.3389/feart.2021.741841
Operational forecasting of volcanic ash and SO<sub>2</sub> clouds is challenging due to the large uncertainties that typically exist on the eruption source term and the mass removal mechanisms occurring downwind. Current operational forecast systems build on single-run deterministic scenarios that do not account for model input uncertainties and their propagation in time during transport. An ensemble-based forecast strategy has been implemented in the FALL3D-8.1 atmospheric dispersal model to configure, execute, and post-process an arbitrary number of ensemble members in a parallel workflow. In addition to intra-member model domain decomposition, a set of inter-member communicators defines a higher level of code parallelism to enable future incorporation of model data assimilation cycles. Two types of standard products are automatically generated by the ensemble post-process task. On one hand, deterministic forecast products result from some combination of the ensemble members (e.g., ensemble mean, ensemble median, etc.) with an associated quantification of forecast uncertainty given by the ensemble spread. On the other hand, probabilistic products can also be built based on the percentage of members that verify a certain threshold condition. The novel aspect of FALL3D-8.1 is the automatisation of the ensemble-based workflow, including an eventual model validation. To this purpose, novel categorical forecast diagnostic metrics, originally defined in deterministic forecast contexts, are generalised here to probabilistic forecasts in order to have a unique set of skill scores valid to both deterministic and probabilistic forecast contexts. Ensemble-based deterministic and probabilistic approaches are compared using different types of observation datasets (satellite cloud detection and retrieval and deposit thickness observations) for the July 2018 Ambae eruption in the Vanuatu archipelago and the April 2015 Calbuco eruption in Chile. Both ensemble-based approaches outperform single-run simulations in all categorical metrics but no clear conclusion can be extracted on which is the best option between these two.
This work has been partially funded by the H2020 Center of Excellence for Exascale in Solid Earth (ChEESE) under the Grant Agreement 823 844 and the multi-year PRACE Project Access “Volcanic Ash Hazard and Forecast” (ID 2019 215 114).
Peer Reviewed
Postprint (published version)
20 p.
eng
Frontiers Media
Attribution 3.0 Spain
https://creativecommons.org/licenses/by/4.0/
http://creativecommons.org/licenses/by/3.0/es/
https://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Informàtica::Aplicacions de la informàtica::Aplicacions informàtiques a la física i l‘enginyeria
Volcanic plumes
Aerosols
Ensemble forecast
Volcanic clouds
FALL3D model
Categorical metrics
Ambae eruption
Calbuco eruption
Simulació per ordinador
Ensemble-based forecast of volcanic clouds using FALL3D-8.1
Article
https://www.frontiersin.org/articles/10.3389/feart.2021.741841/full
info:eu-repo/grantAgreement/EC/H2020/823844/EU/Centre of Excellence for Exascale in Solid Earth/ChEESE
Frontiers in Earth Science
9
eprints
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/1218932021-06-06T00:35:58Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Gargallo Peiró, Abel
Avila, Matias
Owen, Herbert
Prieto-Godino, Luis
Folch, Arnau
Barcelona Supercomputing Center
2018-10-04T14:24:12Z
2018-10-04T14:24:12Z
2018-12
Gargallo-Peiró, A. [et al.]. Mesh generation, sizing and convergence for onshore and offshore wind farm Atmospheric Boundary Layer flow simulation with actuator discs. "Journal of computational physics", desembre 2018, vol. 375, p. 209-227.
0021-9991
http://hdl.handle.net/2117/121893
10.1016/j.jcp.2018.08.031
A new mesh generation process for wind farm modeling is presented together with a mesh convergence and sizing analysis for wind farm flow simulations. The generated meshes are tailored to simulate Atmospheric Boundary Layer (ABL) flows on complex terrains modeling the wind turbines as actuator discs. The wind farm mesher is fully automatic and, given the topography and the turbine characteristics (location, diameter and hub height), it generates a hybrid mesh conformal with the actuator discs and refined upwind and downstream. Moreover, it presents smooth element size transitions across scales and avoids extending high-resolution areas to all the domain. We take advantage of our automatic and robust mesher to study the mesh convergence of our RANS solver with linear elements, obtaining quadratic mesh convergence for a quantity of interest in all the tested cases. In addition, we quantify the mesh resolution at the terrain surface and at the actuator discs required to achieve a given numerical error in simulations in onshore and offshore frameworks. Finally, we present the generated meshes and the simulation results for an offshore and an onshore wind farm. We analyze in detail one particular wind direction for both cases, and for the onshore wind farm we use our automatic framework to estimate the yearly production of energy and measuring the error against the actual produced one.
This work has been partially funded by the EU H2020Energy oriented Center of Excellence (EoCoE) for computer applications, the New European Wind Atlas (NEWA) and the High Performance Computing for Energy (HPC4E) projects. We thank Iberdrola Renovables for their collaboration and for providing wind farm data to validate the developed techniques.
Peer Reviewed
Postprint (published version)
19 p.
eng
Elsevier
Attribution-NonCommercial-NoDerivs 4.0 Spain
http://creativecommons.org/licenses/by-nc-nd/4.0/es/
Open Access
Àrees temàtiques de la UPC::Energies
Wind energy
Mesh generation
Hybrid mesh
Mesh optimization
Wind farms
Actuator disc
Topography
Energia eòlica
Mesh generation, sizing and convergence for onshore and offshore wind farm Atmospheric Boundary Layer flow simulation with actuator discs
Article
https://www.sciencedirect.com/science/article/pii/S0021999118305540#ac0010
info:eu-repo/grantAgreement/EC/H2020/676629/EU/Energy oriented Centre of Excellence for computer applications/EoCoE
info:eu-repo/grantAgreement/EC/H2020/689772/EU/HPC for Energy/HPC4E
Journal of computational physics
375
209
227
eprints
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/1107382020-07-23T23:27:43Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Jacquet, P.
van Eester, D.
Lerche, E.
Bobkov, V.
Blackman, T.
Colas, L.
Challis, C.
Czarnecka, A.
Dumortier, P.
Frigione, D.
Durodié, F.
Garzotti, L.
Goniche, M.
Graves, J.
Kazakov, Y.
Kirov, K.
Klepper, C.C.
Krawczyk, N.
Krivska, A.
Mantsinen, Mervi
Monakhov, I.
Nunes, I.
Ongena, J.
Reinke, M.
Rimini, F.
Zhang, W.
JET Contributors
Barcelona Supercomputing Center
2017-11-16T10:53:10Z
2017-11-16T10:53:10Z
2017-10-23
Jacquet, P. [et al.]. ICRH physics and technology achievements in JET-ILW. "EPJ Web of Conferences", 23 Octubre 2017, vol. 157.
2100-014X
http://hdl.handle.net/2117/110738
10.1051/epjconf/201715702004
ICRH was extensively used in the 2015-16 JET-ILW (ITER like wall) experimental campaign; bulk heating together with high-Z impurity chase-out from plasma centre importantly contributed to the good DD fusion performance obtained recently in JET. Power up to 6 MW was launched in H-mode deuterium plasmas and 8 MW during the hydrogen campaign. The ILA was re-installed and contributed positively to the availability of ICRH power. The ILA produces slightly less high-Z impurities than the A2's and the PWI measured via Be line emission on limiters is in the same ballpark. Specific experiments were conducted to optimise ICRH scenarios in preparation for DT in particular the dual frequency scheme, (H)D and (He)D were tested. In addition, it was confirmed that the (D)H scenario is accessible in a ILW environment and the novel 3-ions ICRH scheme was validated experimentally.
This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014-2018 under grant agreement No 633053 and from the RCUK Energy Programme [grant number EP/P012450/1]. The views and opinions expressed herein do not necessarily reflect those of the European Commission 'To obtain further information on the data and models underlying this paper please contact PublicationsManager@ukaea.uk.
Peer Reviewed
Postprint (published version)
7 p.
eng
EDP Sciences
Attribution-NonCommercial-NoDerivs 3.0 Spain
http://creativecommons.org/licenses/by-nc-nd/3.0/es/
Open Access
Àrees temàtiques de la UPC::Física
Fusion reactions
ICRH
JET-ILW
Fusió nuclear controlada
ICRH physics and technology achievements in JET-ILW
Article
https://www.epj-conferences.org/articles/epjconf/abs/2017/26/epjconf_rfppc2017_02004/epjconf_rfppc2017_02004.html
info:eu-repo/grantAgreement/EC/H2020/633053/EU/Implementation of activities described in the Roadmap to Fusion during Horizon 2020 through a Joint programme of the members of the EUROfusion consortium/EUROfusion
EPJ Web of Conferences
157
02004
eprints
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3413672022-02-02T01:25:59Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Mohr, Stephan
Hoevelmann, Felix
Wylde, Jonathan
Schelero, Natascha
Sarria, Juan
Purkayastha, Nirupam
Ward, Zachary
Navarro Acero, Pablo
Michalis, Vasileios K.
Barcelona Supercomputing Center
2021-03-10T10:49:38Z
2022-02-02T01:25:59Z
2021
Mohr, S. [et al.]. Ranking the Efficiency of Gas Hydrate Anti-agglomerants through Molecular Dynamic Simulations. "Journal of Physical Chemistry B", 2021, vol. 125, núm. 5, p. 1487-1502.
1520-6106
https://arxiv.org/pdf/2010.01098.pdf
http://hdl.handle.net/2117/341367
10.1021/acs.jpcb.0c08969
Using both computational and experimental methods, the capacity of four different surfactant molecules to inhibit the agglomeration of sII hydrate particles was assessed. The computational simulations were carried out using both steered and non-steered molecular dynamics (MD), simulating the coalescence process of a hydrate slab and a water droplet, both covered with surfactant molecules. The surfactants were ranked according to free energy calculations (steered MD) and the number of agglomeration events (non-steered MD). The experimental work was based on rocking cell measurements, determining the minimum effective dose necessary to inhibit agglomeration. Overall, good agreement was obtained between the performance predicted by the simulations and the experimental measurements. Moreover, the simulations allowed us to gain additional insights that are not directly accessible via experiments, such as an analysis of the mass density profiles, the diffusion coefficients, or the orientations of the long tails.
The authors thank Clariant for the financial support and to allow for the work to be published.
Peer Reviewed
Postprint (author's final draft)
16 p.
eng
American Chemical Society
Àrees temàtiques de la UPC::Enginyeria química::Química física
Computer simulation
Hydrocarbons
Molecular dynamics
Surface active agents
Molecular dynamic simulations
Gas hydrate anti-agglomerants
Computational simulations
Simulació per ordinador
Molècules
Ranking the Efficiency of Gas Hydrate Anti-agglomerants through Molecular Dynamic Simulations
Article
https://doi.org/10.1021/acs.jpcb.0c08969
Open Access
Journal of Physical Chemistry B
125
5
1487
1502
eprints
oai:upcommons.upc.edu:2117/3521372023-01-01T01:20:46Zcom_2117_3911com_2117_28579com_2117_28577com_2117_3123com_2117_28581com_2117_184555com_2117_184544com_2117_80515com_2117_23714com_2117_28578com_2117_15797col_2117_3912col_2117_3124col_2117_184721col_2117_80523col_2117_3055openAccess
García Calatrava, Carlos
Becerra Fontal, Yolanda
Cucchietti, Fernando
Diví Cuesta, Carla
Universitat Politècnica de Catalunya. Doctorat en Arquitectura de Computadors
Universitat Politècnica de Catalunya. Departament d'Arquitectura de Computadors
Barcelona Supercomputing Center
Universitat Politècnica de Catalunya. CAP - Grup de Computació d'Altes Prestacions
2021-09-23T10:23:31Z
2021-09-23T10:23:31Z
2021-08-13
Garcia, C. [et al.]. NagareDB: A resource-efficient document-oriented time-series database. "Data", 13 Agost 2021, vol. 6, núm. 8, article 91, p. 1-20.
2306-5729
http://hdl.handle.net/2117/352137
10.3390/data6080091
The recent great technological advance has led to a broad proliferation of Monitoring Infrastructures, which typically keep track of specific assets along time, ranging from factory machinery, device location, or even people. Gathering this data has become crucial for a wide number of applications, like exploration dashboards or Machine Learning techniques, such as Anomaly Detection. Time-Series Databases, designed to handle these data, grew in popularity, becoming the fastest-growing database type from 2019. In consequence, keeping track and mastering those rapidly evolving technologies became increasingly difficult. This paper introduces the holistic design approach followed for building NagareDB, a Time-Series database built on top of MongoDB—the most popular NoSQL Database, typically discouraged in the Time-Series scenario. The goal of NagareDB is to ease the access to three of the essential resources needed to building time-dependent systems: Hardware, since it is able to work in commodity machines; Software, as it is built on top of an open-source solution; and Expert Personnel, as its foundation database is considered the most popular NoSQL DB, lowering its learning curve. Concretely, NagareDB is able to outperform MongoDB recommended implementation up to 4.7 times, when retrieving data, while also offering a stream-ingestion up to 35% faster than InfluxDB, the most popular Time-Series database. Moreover, by relaxing some requirements, NagareDB is able to reduce the disk space usage up to 40%.
This research was partly supported by the H2020 IoTwins project (Distributed Digital Twins for industrial SMEs: a big-data platform) funded by the EU under the call ICT-11-2018-2019, Grant Agreement No 857191, by the Spanish Ministry of Science and Innovation (contract PID2019- 107255GB) and by the Generalitat de Catalunya (contract 2017-SGR-1414).
Peer Reviewed
Postprint (published version)
20 p.
eng
Attribution 4.0 International
https://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Informàtica::Sistemes d'informació::Bases de dades
Information storage and retrieval systems
Time series database
Resource-saving approach
Document-oriented database
Data stream
MongoDB
Informació -- Sistemes d'emmagatzematge i recuperació
NagareDB: A resource-efficient document-oriented time-series database
Article
https://www.mdpi.com/2306-5729/6/8/91
info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PID2019-107255GB-C22/ES/UPC-COMPUTACION DE ALTAS PRESTACIONES VIII/
info:eu-repo/grantAgreement/AGAUR/2017 SGR 1414
info:eu-repo/grantAgreement/EC/H2020/857191/EU/Distributed Digital Twins for industrial SMEs: a big-data platform/IoTwins
32049182
García, C.; Becerra, Y.; Cucchietti, F. M.; Diví, C.
Data
6
8, article 91
1
20
eprints
10.13039/501100011033
Agencia Estatal de Investigación
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3934622023-10-16T15:07:20Zcom_2117_98851com_2117_28581com_2117_28577com_2117_3989com_2117_28579com_2117_80515com_2117_23714com_2117_28578com_2117_184576com_2117_184544com_2117_15797col_2117_103655col_2117_3990col_2117_80523col_2117_184713col_2117_3055openAccess
Eiximeno Franch, Benet
Tur Monge, Carlos
Lehmkuhl Barba, Oriol
Rodríguez Pérez, Ivette María
Universitat Politècnica de Catalunya. Doctorat en Física Computacional i Aplicada
Universitat Politècnica de Catalunya. Departament de Màquines i Motors Tèrmics
Barcelona Supercomputing Center
Universitat Politècnica de Catalunya. TUAREG - Turbulence and Aerodynamics in Mechanical and Aerospace Engineering Research Group
2023-09-14T06:36:25Z
2023-09-14T06:36:25Z
2023-08-21
Eiximeno, B. [et al.]. Hybrid computation of the aerodynamic noise radiated by the wake of a subsonic cylinder. "Fluids", 21 Agost 2023, vol. 8, núm. 8, article 236.
2311-5521
http://hdl.handle.net/2117/393462
10.3390/fluids8080236
The noise radiated by the flow around a cylinder in the subcritical regime at 𝑅𝑒𝐷=1×104 and at a subsonic Mach number of 𝑀=0.5 is here studied. The aerodynamic sound radiated by a cylinder has been studied with a wide range of Reynolds numbers, but there are no studies about how the Mach number affects the acoustic field in the subsonic regime. The flow field is resolved by means of large-eddy simulations of the compressible Navier–Stokes equations. For the study of the noise propagation, formulation 1C of the Ffowcs Williams–Hawkings analogy is used. The fluid flow results show good agreement when comparing the surface pressure coefficient, the recirculation length, the vortex shedding frequency and the force coefficients against other studies performed under similar conditions. The dynamic mode decomposition of the pressure fluctuations is used to relate them with the far-field noise. It is shown that, in contrast to what happens for low Mach numbers, quadrupoles have a significant impact mainly in the observers located in the streamwise direction. This effect leads to a global monopole directivity pattern as the shear fluctuations compensate for the lower value of the aeolian tone away from the cross-stream direction.
This work was partially financially supported by the Ministerio de Economía, Industria y Competitividad, Secretaría de Estado de Investigación, Desarrollo e Innovación, Spain (refs PID2020-116937RB-C21 and PID2020-116937RB-C22). B. Eiximeno’s work was funded by a contract from the Subprograma de Ayudas Predoctorales given by the Ministerio de Ciencia e Innovación (PRE2021-096927). O. Lehmkuhl’s work was financed by a Ramón y Cajal postdoctoral contract from the Ministerio de Economía y Competitividad, Secretaría de Estado de Investigación, Desarrollo e Innovación, Spain (RYC2018-025949-I).
Peer Reviewed
Postprint (published version)
eng
Multidisciplinary Digital Publishing Institute (MDPI)
Attribution 4.0 International
http://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Enginyeria mecànica::Mecànica de fluids
Àrees temàtiques de la UPC::Aeronàutica i espai::Aerodinàmica
Aerodynamic noise
Aeroacoustics
Cylinders
Noise
Ffowcs Williams–Hawkings
Large-eddy simulations
Dynamic mode decomposition
Cilindres
Soroll
Hybrid computation of the aerodynamic noise radiated by the wake of a subsonic cylinder
Article
https://www.mdpi.com/2311-5521/8/8/236
info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PID2020-116937RB-C22/ES/TOWARDS REAL-TIME ACTUATION STRATEGIES FOR FLOW CONTROL AND NOISE REDUCTION IN AIRCRAFTS./
36998570
Eiximeno, B.; Tur, C.; Lehmkuhl , O.; Rodriguez, I.
Fluids
8
8, article 236
eprints
10.13039/501100011033
Agencia Estatal de Investigación
oai:upcommons.upc.edu:2117/3286202021-09-12T00:52:52Zcom_2117_3911com_2117_28579com_2117_28577com_2117_115277com_2117_28581com_2117_80515com_2117_23714com_2117_28578com_2117_15797col_2117_3912col_2117_119980col_2117_80523col_2117_3055openAccess
Otero Calviño, Beatriz
Rodríguez Luna, Eva
Rojas, Otilio
Verdú Mulà, Javier
Costa Prats, Juan José
Pajuelo González, Manuel Alejandro
Canal Corretger, Ramon
Universitat Politècnica de Catalunya. Departament d'Arquitectura de Computadors
Barcelona Supercomputing Center
Universitat Politècnica de Catalunya. VIRTUOS - Virtualisation and Operating Systems
2020-09-10T07:15:19Z
2021-08-31T00:26:12Z
2021-07
Otero, B. [et al.]. A cost-efficient QoS-aware analytical model of future software content delivery networks. "International journal of network management", Juliol/Agost 2021, vol. 31, núm. 4, article e2137, p. 1-24.
1055-7148
http://hdl.handle.net/2117/328620
10.1002/nem.2137
Freelance, part-time, work-at-home, and other flexible jobs are changing the concept of workplace, and bringing information and content exchange problems to companies. Geographically spread corporations may use remote distribution of software and data to attend employees' demands, by exploiting emerging delivery technologies. In this context, cost-efficient software distribution is crucial to allow business evolution and make IT infrastructures more agile. On the other hand, container based virtualization technology is shaping the new trends of software deployment and infrastructure design. We envision current and future enterprise IT management trends evolving towards container based software delivery over Hybrid CDNs. This paper presents a novel cost-efficient QoS aware analytical model and a Hybrid CDN-P2P architecture for enterprise software distribution.
The model would allow delivery cost minimization for a wide range of companies, from big multinationals to SMEs, using CDN-P2P distribution under various industrial hypothetical scenarios. Model constraints guarantee acceptable deployment times and keep interchanged content amounts below the bandwidth and storage network limits in our scenarios. Indeed, key model parameters account for network bandwidth, storage limits and rental prices, which are empirically determined from their offered values by the commercial delivery networks KeyCDN, MaxCDN, CDN77 and BunnyCDN. This preliminary study indicates that MaxCDN offers the best cost-QoS trade-off. The model is implemented in the network simulation tool PeerSim, and then applied to diverse testing scenarios by varying company types, number and profile (either, technical or administrative) of employees and the number and size of content requests. Hybrid simulation results show overall economic savings between 5\% and 20\%, compared to just hiring resources from a commercial CDN, while guaranteeing satisfactory QoS levels in terms of deployment times and number of served requests.
This work was partially supported by Generalitat de Catalunya under the SGR Program (2017-SGR-962) and the RIS3CAT DRAC Project (001-P-001723). We have also received funding from Ministry of Science and Innovation (Spain) under the project EQC2019-005653-P.
Peer Reviewed
Postprint (author's final draft)
24 p.
eng
Àrees temàtiques de la UPC::Informàtica::Enginyeria del software
Quality of service (Computer networks)
Computer software industry
Cost-efficiency
Hybrid architecture
Containers
P2P
CDN
Programari -- Indústria i comerç
A cost-efficient QoS-aware analytical model of future software content delivery networks
Article
https://onlinelibrary.wiley.com/doi/abs/10.1002/nem.2137
info:eu-repo/grantAgreement/GENCAT/RIS3CAT/IU16-011643 VIRTUOS P4
info:eu-repo/grantAgreement/MICINN/EQC2019-005653-P
Open Access
29187564
Otero, B.; Rodríguez, E.; Rojas, O.; Verdú, J.; Costa, J.; Pajuelo, M.A.; Canal, R.
International journal of network management
31
4, article e2137
1
24
eprints
oai:upcommons.upc.edu:2117/3753452022-11-06T20:35:15Zcom_2117_3911com_2117_28579com_2117_28577com_2117_115277com_2117_28581com_2117_80515com_2117_23714com_2117_28578com_2117_15797col_2117_3912col_2117_119980col_2117_80523col_2117_3055
Mus León, Sergi
Otero Calviño, Beatriz
Alvarado Vivas, Leonardo
Canal Corretger, Ramon
Rojas Ulacio, Otilio
Universitat Politècnica de Catalunya. Departament d'Arquitectura de Computadors
Barcelona Supercomputing Center
Universitat Politècnica de Catalunya. VIRTUOS - Virtualisation and Operating Systems
2022-11-02T09:07:29Z
2022-11-15
2024-06-11
Mus, S. [et al.]. Small-layered feed-forward and convolutional neural networks for efficient P wave earthquake detection. "Expert systems with applications", 15 Novembre 2022, vol. 206, article 117749, p. 1-11.
0957-4174
http://hdl.handle.net/2117/375345
10.1016/j.eswa.2022.117749
The number and efficiency of seismic networks have steadily increase over time delivering large datasets to be analyzed for earthquake occurrence. Automatic tools for accurate earthquake detection are under emerging and intense development. This paper first proposes a new windowing procedure of seismic traces that highly facilitates earthquake detection. This procedure applies regular trace filtering and normalization, but also performs a strict window alignment to P wave onset. These event-aligned windows represent the input data to our P wave detection networks, with relatively small or moderate number of layers. We then develop Feed-Forward (FFNN) and Convolutional (CNN) neural networks and explore multiple architecture configurations to find relevant hyperparameter patterns for better detection. To assess network performance, we adopt the widely used metrics of accuracy (ACC) and the area under the curve (AUC) of the Receiver Operating Characteristic function. In terms of ACC, the best FFNN and CNN reach performances of 91% and 98%, respectively. On the other hand, the best FFNN and CNN in terms of AUC achieve performances of 96% and 99%, respectively. Thus, our novel trace windowing procedure allows developing networks with few hyperparameters, for correct earthquake detection under low computational costs. Finally, we use the CNN with best AUC performance as an effective trace filtering with the purpose of P wave arrival time estimation.
This work is partially supported by the Generalitat de Catalunya under grant 2017-SGR-962 and the DRAC project (001-P-001723). The research leading to these results has received funding from the European Union’s Horizon 2020 research and innovation programme under the ChEESE project, grant agreement No. 823844. This project has also received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 777778 MATHROCKS.
Peer Reviewed
Postprint (author's final draft)
11 p.
eng
Attribution-NonCommercial-NoDerivatives 4.0 International
http://creativecommons.org/licenses/by-nc-nd/4.0/
Restricted access - publisher's policy
Àrees temàtiques de la UPC::Informàtica::Arquitectura de computadors
Àrees temàtiques de la UPC::Informàtica::Aplicacions de la informàtica::Aplicacions informàtiques a la física i l‘enginyeria
Neural networks (Computer science)
Earthquake prediction
Artificial neural networks
Feed-forward
Convolutional
Earthquake detection
P waves
Xarxes neuronals (Informàtica)
Terratrèmols -- Predicció
Small-layered feed-forward and convolutional neural networks for efficient P wave earthquake detection
Article
https://www.sciencedirect.com/science/article/pii/S0957417422010296
info:eu-repo/grantAgreement/EC/H2020/777778/EU/Multiscale Inversion of Porous Rock Physics using High-Performance Simulators: Bridging the Gap between Mathematics and Geophysics/MATHROCKS
info:eu-repo/grantAgreement/EC/H2020/823844/EU/Centre of Excellence for Exascale in Solid Earth/ChEESE
34160142
Mus, S.; Otero, B.; Alvarado, L.; Canal, R.; Rojas, O.
Expert systems with applications
206
article 117749
1
11
eprints
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3459652023-10-09T07:53:34Zcom_2117_80516com_2117_23714com_2117_28578com_2117_28577com_2117_80515col_2117_80530col_2117_80523openAccess
Martínez Ruiz, Daniel
Huete, Cesar
Martínez Ferrer, Pedro J.
Mira Martínez, Daniel
Barcelona Supercomputing Center
2021-05-20T14:27:46Z
2022-01-04T01:26:15Z
2021
Martínez Ruiz, D. [et al.]. Specific heat effects in two-dimensional shock refractions. "Shock Waves", 2021, vol. 31, p. 1-17.
0938-1287
1432-2153
http://hdl.handle.net/2117/345965
10.1007/s00193-020-00977-6
Compressible mixtures in supersonic flows are subject to significant temperature changes via shock waves and expansions, which affect several properties of the flow. Besides the widely studied variable transport effects such as temperature-dependent viscosity and conductivity, vibrational and rotational molecular energy storage is also modified through the variation of the heat capacity cp and heat capacity ratio γ, especially in hypersonic flows. Changes in the composition of the mixture may also modify its value through the species mass fraction Yα, thereby affecting the compression capacity of the flow. Canonical configurations are studied here to explore their sharply conditioned mechanical equilibrium under variations of these thermal models. In particular, effects of cp(T,Yα) and γ(T,Yα) on the stability of shock-impinged supersonic shear and mixing layers are addressed, on condition that a shock wave is refracted. It is found that the limits defining regular structures are affected (usually broadened out) by the dependence of heat capacities with temperature. Theoretical and high-fidelity numerical simulations exhibit a good agreement in the prediction of regular shock reflections and their post-shock aerothermal properties.
Work produced with the support of a 2019 Leonardo Grant for Researchers and Cultural Creators, BBVA Foundation and Project PID2019-108592RB-C41 and PID2019-108592RA-C43 (MICINN/ FEDER, UE). Numerical simulations were carried out on the MareNostrum 4 supercomputer with the Grant RES FI-2019-1-0046. The authors gratefully acknowledge Arnaud Mura, CNRS researcher at Institut PPRIME in France, for the numerical tool CREAMS.
Peer Reviewed
Postprint (author's final draft)
17 p.
eng
Springer
Àrees temàtiques de la UPC::Informàtica::Aplicacions de la informàtica::Aplicacions informàtiques a la física i l‘enginyeria
Shock waves.
Vortex generators
Shock waves
Shear layers
Specific heats
Thermally perfect gas
Hypersonic flow
Energia -- Models matemàtics
Specific heat effects in two-dimensional shock refractions
Article
https://link.springer.com/article/10.1007/s00193-020-00977-6#
Open Access
Shock Waves
31
1
17
eprints
oai:upcommons.upc.edu:2117/3663412022-05-01T15:04:58Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Stroth, Ulrich
Aguiam, Diogo
Alessi, Edoardo
Angioni, Clemente
Arden, Nils
Futatani, Shimpei
Gallart Escolà, Daniel
Mantsinen, Mervi
Barcelona Supercomputing Center
2022-04-26T12:26:07Z
2022-04-26T12:26:07Z
2022-03
Stroth, U. [et al.]. Progress from ASDEX Upgrade experiments in preparing the physics basis of ITER operation and DEMO scenario development. "Nuclear Fusion", Març 2022, vol. 62, núm. 4, 042006.
0029-5515
1741-4326
http://hdl.handle.net/2117/366341
10.1088/1741-4326/ac207f
An overview of recent results obtained at the tokamak ASDEX Upgrade (AUG) is given. A work flow for predictive profile modelling of AUG discharges was established which is able to reproduce experimental H-mode plasma profiles based on engineering parameters only. In the plasma center, theoretical predictions on plasma current redistribution by a dynamo effect were confirmed experimentally. For core transport, the stabilizing effect of fast ion distributions on turbulent transport is shown to be important to explain the core isotope effect and improves the description of hollow low-Z impurity profiles. The L–H power threshold of hydrogen plasmas is not affected by small helium admixtures and it increases continuously from the deuterium to the hydrogen level when the hydrogen concentration is raised from 0 to 100%. One focus of recent campaigns was the search for a fusion relevant integrated plasma scenario without large edge localised modes (ELMs). Results from six different ELM-free confinement regimes are compared with respect to reactor relevance: ELM suppression by magnetic perturbation coils could be attributed to toroidally asymmetric turbulent fluctuations in the vicinity of the separatrix. Stable improved confinement mode plasma phases with a detached inner divertor were obtained using a feedback control of the plasma β. The enhanced Dα H-mode regime was extended to higher heating power by feedback controlled radiative cooling with argon. The quasi-coherent exhaust regime was developed into an integrated scenario at high heating power and energy confinement, with a detached divertor and without large ELMs. Small ELMs close to the separatrix lead to peeling-ballooning stability and quasi continuous power exhaust. Helium beam density fluctuation measurements confirm that transport close to the separatrix is important to achieve the different ELM-free regimes. Based on separatrix plasma parameters and interchange-drift-Alfvén turbulence, an analytic model was derived that reproduces the experimentally found important operational boundaries of the density limit and between L- and H-mode confinement. Feedback control for the X-point radiator (XPR) position was established as an important element for divertor detachment control. Stable and detached ELM-free phases with H-mode confinement quality were obtained when the XPR was moved 10 cm above the X-point. Investigations of the plasma in the future flexible snow-flake divertor of AUG by means of first SOLPS-ITER simulations with drifts activated predict beneficial detachment properties and the activation of an additional strike point by the drifts.
This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014–2018 and 2019–2020 under Grant Agreement No. 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission.
Peer Reviewed
Postprint (published version)
"Article signat per més de 50 autors/es: U. Stroth, D. Aguiam, E. Alessi, C. Angioni, N. Arden, R. Arredondo Parra, V. Artigues, O. Asunta, M. Balden, V. Bandaru, A. Banon-Navarro, K. Behler, A. Bergmann, M. Bergmann, J. Bernardo, M. Bernert, A. Biancalani, R. Bielajew, R. Bilato, G. Birkenmeier, T. Blanken, V. Bobkov, A. Bock, T. Body, T. Bolzonella, N. Bonanomi, A. Bortolon, B. Böswirth, C. Bottereau, A. Bottino, H. van den Brand, M. Brenzke, S. Brezinsek, D. Brida, F. Brochard, C. Bruhn, J. Buchanan, A. Buhler, A. Burckhart, Y. Camenen, B. Cannas, P. Cano Megias, D. Carlton, M. Carr, P. Carvalho, C. Castaldo, M. Cavedon, C. Cazzaniga, C. Challis, A. Chankin, C. Cianfarani, F. Clairet, S. Coda, R. Coelho, J.W. Coenen, L. Colas, G. Conway, S. Costea, D. Coster, T. Cote, A.J. Creely, G. Croci, D.J. Cruz Zabala, G. Cseh, A. Czarnecka, I. Cziegler, O. D'Arcangelo, A. Dal Molin, P. David, C. Day, M. de Baar, P. de Marné, R. Delogu, S. Denk, P. Denner, A. Di Siena, J.J. Dominguez Palacios Durán, D. Dunai, A. Drenik, M. Dreval, R. Drube, M. Dunne, B.P. Duval, R. Dux, T. Eich, S. Elgeti, A. Encheva, K. Engelhardt, B. Erdös, I. Erofeev, B. Esposito, E. Fable, M. Faitsch, U. Fantz, M. Farnik, H. Faugel, F. Felici, O. Ficker, S. Fietz, A. Figueredo, R. Fischer, O. Ford, L. Frassinetti, M. Fröschle, G. Fuchert, J.C. Fuchs, H. Fünfgelder, S. Futatani, K. Galazka, J. Galdon-Quiroga, D. Gallart Escolà, A. Gallo10, Y. Gao11, S. Garavaglia3, M. Garcia Muñoz16, B. Geiger21, L. Giannone1, S. Gibson32, L. Gil2, E. Giovannozzi18, S. Glöggler1, M. Gobbin8, J. Gonzalez Martin, T. Goodman, G. Gorini, T. Görler, D. Gradic, G. Granucci, A. Gräter, H. Greuner, M. Griener, M. Groth, A. Gude, L. Guimarais, S. Günter, G. Haas, A.H. Hakola, C. Ham, T. Happel, N. den Harder, G. Harrer, J. Harrison, V. Hauer, T. Hayward-Schneider, B. Heinemann, T. Hellsten, S. Henderson, P. Hennequin, A. Herrmann, E. Heyn, F. Hitzler, J. Hobirk, K. Höfler, J.H. Holm, M. Hölzl, C. Hopf, L. Horvath, T. Höschen, A. Houben, A. Hubbard, A. Huber, K. Hunger, V. Igochine, M. Iliasova, T. Ilkei, K. Insulander Björk, C. Ionita-Schrittwieser, I. Ivanova-Stanik, W. Jacob, N. Jaksic, F. Janky, A. Jansen van Vuuren, A. Jardin, F. Jaulmes, F. Jenko, T. Jensen, E. Joffrin, A. Kallenbach, S. Kálvin, M. Kantor, A. Kappatou, O. Kardaun, J. Karhunen4, C.-P. Käsemann, S. Kasilov, A. Kendl, W. Kernbichler, E. Khilkevitch, A. Kirk, S. Kjer Hansen, V. Klevarova, G. Kocsis, M. Koleva, M. Komm, M. Kong, A. Krämer-Flecken, K. Krieger, A. Krivska, O. Kudlacek, T. Kurki-Suonio, B. Kurzan, B. Labit, K. Lackner, F. Laggner, A. Lahtinen, P.T. Lang, P. Lauber, N. Leuthold, L. Li, J. Likonen, O. Linder, B. Lipschultz, Y. Liu, A. Lohs, Z. Lu, T. Luda di Cortemiglia, N.C. Luhmann, T. Lunt, A. Lyssoivan, T. Maceina, J. Madsen, A. Magnanimo, H. Maier, J. Mailloux, R. Maingi, O. Maj, E. Maljaars, P. Manas, A. Mancini, A. Manhard, P. Mantica, M. Mantsinen, P. Manz, M. Maraschek, C. Marchetto, L. Marrelli, P. Martin, A. Martitsch, F. Matos, M. Mayer, M.-L. Mayoral, D. Mazon, P.J. McCarthy, R. McDermott, R. Merkel, A. Merle, D. Meshcheriakov, H. Meyer, D. Milanesio, P. Molina Cabrera, F. Monaco, M. Muraca, F. Nabais, V. Naulin, R. Nazikian, R.D. Nem, A. Nemes-Czopf, G. Neu, R. Neu, A.H. Nielsen, S.K. Nielsen, T. Nishizawa, M. Nocente, J.-M. Noterdaeme, I. Novikau, S. Nowak, M. Oberkofler, R. Ochoukov, J. Olsen, F. Orain, F. Palermo, O. Pan, G. Papp, I. Paradela Perez, A. Pau, G. Pautasso, C. Paz-Soldan, P. Petersson, P. Piovesan, C. Piron, U. Plank, B. Plaum, B. Plöck, V. Plyusnin, G. Pokol, E. Poli, L. Porte, T. Pütterich, M. Ramisch, J. Rasmussen, G. Ratta, S. Ratynskaia, G. Raupp, D. Réfy, M. Reich1, F. Reimold, D. Reiser, M. Reisner, D. Reiter, T. Ribeiro, R. Riedl, J. Riesch, D. Rittich, J.F. Rivero Rodriguez, G. Rocchi, P. Rodriguez-Fernandez, M. Rodriguez-Ramos, V. Rohde, G. Ronchi, A. Ross, M. Rott, M. Rubel, D.A. Ryan, F. Ryter, S. Saarelma, M. Salewski, A. Salmi, O. Samoylov, L. Sanchis Sanchez, J. Santos, O. Sauter, G. Schall, K. Schlüter, K. Schmid, O. Schmitz, P.A. Schneider, R. Schrittwieser, M. Schubert, C. Schuster, T. Schwarz-Selinger, J. Schweinzer, E. Seliunin, A. Shabbir, A. Shalpegin, S. Sharapov, U. Sheikh, A. Shevelev, G. Sias, M. Siccinio, B. Sieglin, A. Sigalov, A. Silva, C. Silva, D. Silvagni, J. Simpson, S. Sipilä, E. Smigelskis, A. Snicker, E. Solano, C. Sommariva, C. Sozzi, G. Spizzo, M. Spolaore, A. Stegmeir, M. Stejner, J. Stober, E. Strumberge1, G. Suarez Lopez, H.-J. Sun, W. Suttrop, E. Sytova, T. Szepesi, B. Tál, T. Tala, G. Tardini, M. Tardocchi, D. Terranova, M. Teschke, E. Thorén, W. Tierens, D. Told, W. Treutterer, G. Trevisan, E. Trier, M. Tripský, M. Usoltceva, M. Valisa, M. Valovic, M. van Zeeland, F. Vannini, B. Vanovac, P. Varela, S. Varoutis, N. Vianello, J. Vicente, G. Verdoolaege, T. Vierle, E. Viezzer, I. Voitsekhovitch, U. von Toussaint, D. Wagner, X. Wang, M. Weiland, A.E. White, M. Willensdorfer, B. Wiringer, M. Wischmeier, R. Wolf, E. Wolfrum, Q. Yang, Q. Yu, R. Zagórski, I. Zammuto, T. Zehetbauer, W. Zhang, W. Zholobenko, M. Zilker, A. Zito, H. Zohm, S. Zoletnik and the EUROfusion MST1 Team "
18 p.
eng
IOP Publishing
Attribution 3.0 Spain
Attribution 4.0 International (CC BY 4.0)
http://creativecommons.org/licenses/by/3.0/es/
https://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Informàtica::Aplicacions de la informàtica::Aplicacions informàtiques a la física i l‘enginyeria
Nuclear fusion
Turbulence
Fusion reactors
Asdex Upgrade
Confinement
ELLM-free discharges
Simulació per ordinador
Progress from ASDEX Upgrade experiments in preparing the physics basis of ITER operation and DEMO scenario development
Article
https://iopscience.iop.org/article/10.1088/1741-4326/ac207f
info:eu-repo/grantAgreement/EC/H2020/633053/EU/Implementation of activities described in the Roadmap to Fusion during Horizon 2020 through a Joint programme of the members of the EUROfusion consortium/EUROfusion
042006
Nuclear Fusion
62
4
eprints
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3311562020-11-08T18:26:40Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Pérez Salinas, Adrián
Cervera Lierta, Alba
Gil Fuster, Elies
Latorre, José Ignacio
Barcelona Supercomputing Center
2020-11-02T17:47:57Z
2020-11-02T17:47:57Z
2020
Pérez Salinas, A. [et al.]. Data re-uploading for a universal quantum classifier. "Quantum", 2020, vol. 4, 226.
2521-327X
http://hdl.handle.net/2117/331156
10.22331/q-2020-02-06-226
A single qubit provides sufficient computational capabilities to construct a universal quantum classifier when assisted with a classical subroutine. This fact may be surprising since a single qubit only offers a simple superposition of two states and single-qubit gates only make a rotation in the Bloch sphere. The key ingredient to circumvent these limitations is to allow for multiple
data re-uploading
. A quantum circuit can then be organized as a series of data re-uploading and single-qubit processing units. Furthermore, both data re-uploading and measurements can accommodate multiple dimensions in the input and several categories in the output, to conform to a universal quantum classifier. The extension of this idea to several qubits enhances the efficiency of the strategy as entanglement expands the superpositions carried along with the classification. Extensive benchmarking on different examples of the single- and multi-qubit quantum classifier validates its ability to describe and classify complex data
APS and JIL acknowledge CaixaBank for its support of this work through Barcelona Supercomputing Center project CaixaBank Computacion Cuantica. The authors acknowledge the interesting discussions with Quantic group team members. The authors also acknowledge Xanadu Quantum Computing, in particular Shahnawaz Ahmed, for writing a tutorial of this quantum classifier using its full-stack library Pennylane
Peer Reviewed
Postprint (published version)
19 p.
eng
Verein zur Förderung des Open Access Publizierens in den Quantenwissenschaften
Attribution 3.0 Spain
Attribution 4.0 International (CC BY 4.0)
http://creativecommons.org/licenses/by/3.0/es/
https://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Informàtica
Quantum computers
Universal quantum classifier
Qubit
Multiple data re-uploading
Quantum Computation
Ordinadors quàntics
Data re-uploading for a universal quantum classifier
Article
https://quantum-journal.org/papers/q-2020-02-06-226/
226
Quantum
4
eprints
oai:upcommons.upc.edu:2117/3738222023-09-17T00:44:36Zcom_2117_184560com_2117_184544com_2117_28577com_2117_80515com_2117_23714com_2117_28578col_2117_184705col_2117_80523
Calmet, Hadrien
Oks, David
Santiago, Alfonso
Houzeaux, Guillaume
Le Corfec, Antoine
Deruyver, Laura
Rigaut, Clement
Lambert, Pierre
Haut, Benoit
Goole, Jonathan
Barcelona Supercomputing Center
Universitat Politècnica de Catalunya. Doctorat en Matemàtica Aplicada
2022-09-30T14:20:45Z
2022
2024-08-24
Calmet, H. [et al.]. Validation and Sensitivity analysis for a nasal spray deposition computational model. "International Journal of Pharmaceutics", 2022, vol. 626, article 122118.
0378-5173
http://hdl.handle.net/2117/373822
10.1016/j.ijpharm.2022.122118
Validating numerical models against experimental models of nasal spray deposition is challenging since many aspects must be considered. That being said, it is a critical step in the product development process of nasal spray devices. This work presents the validation process of a nasal deposition model, which demonstrates a high degree of consistency of the numerical model with experimental data when the nasal cavity is segmented into two regions but not into three. Furthermore, by modelling the flow as stationary, the computational cost is drastically reduced while maintaining quality of particle deposition results. Thanks to this reduction, a sensitivity analysis of the numerical model could be performed, consisting of 96 simulations. The objective was to quantify the impact of four inputs: the spray half cone angle, mean spray exit velocity, breakup length from the nozzle exit and the diameter of the nozzle spray device, on the three quantities of interest: the percentage of the accumulated number of particles deposited on the anterior, middle and posterior sections of the nasal cavity. The results of the sensitivity analysis demonstrated that the deposition on anterior and middle sections are sensitive to injection angle and breakup length, and the deposition on posterior section is only, but highly, sensitive to the injection velocity.
Peer Reviewed
Postprint (author's final draft)
11 p.
eng
Elsevier
Attribution-NonCommercial-NoDerivatives 4.0 International
http://creativecommons.org/licenses/by-nc-nd/4.0/
Restricted access - publisher's policy
Àrees temàtiques de la UPC::Informàtica::Aplicacions de la informàtica::Aplicacions informàtiques a la física i l‘enginyeria
Computational fluid dynamics
Intranasal medication
Nasal spray
CFPD
Experimental model
Nasal drug delivery
Sensitivity analysis
Simulació per ordinador
Validation and Sensitivity analysis for a nasal spray deposition computational model
Article
https://www.sciencedirect.com/science/article/pii/S037851732200672X
35572236
article 122118
International Journal of Pharmaceutics
626
eprints
oai:upcommons.upc.edu:2117/3991292024-02-26T14:56:48Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577com_2117_15797col_2117_80523col_2117_3055openAccess
Monterrubio Velasco, Marisol
Lana Pons, Francisco Javier
Arámbula Mendoza, Raúl
2024-01-11T10:33:10Z
2024-01-11T10:33:10Z
2023-12-08
Monterrubio, M.; Lana, F.J.; Arámbula-Mendoza, R. Uncertainties, complexities and possible forecasting of Volcán de Colima energy emissions (Mexico, years 2013–2015) based on a fractal reconstruction theorem. "Nonlinear processes in geophysics", 8 Desembre 2023, vol. 30, núm. 4, p. 571-583.
1607-7946
http://hdl.handle.net/2117/399129
10.5194/npg-30-571-2023
The effusive–explosive energy emission process in a volcano is a dynamic and complex physical phenomenon. The importance of quantifying this complexity in terms of the physical and mathematical mechanisms that govern these emissions should be a requirement for deciding to apply a possible forecasting strategy with a sufficient degree of certainty. The complexity of this process is determined in this research by means of the reconstruction theorem and statistical procedures applied to the effusive–explosive volcanic energy emissions corresponding to the activity in the Volcán de Colima (western segment of the Trans-Mexican Volcanic Belt) along the years 2013–2015. The analysis is focused on measuring the degree of persistence or randomness of the series, the degree of predictability of energy emissions, and the quantification of the degree of complexity and “memory loss” of the physical mechanism throughout an episode of volcanic emissions. The results indicate that the analysed time series depict a high degree of persistence and low memory loss, making the mentioned effusive–explosive volcanic emission structure a candidate for successfully applying a forecasting strategy.
This research has been supported by the European High-Performance Computing Joint Undertaking (JU) as well as Spain, Italy, Iceland, Germany, Norway, France, Finland and Croatia under grant agreement no.101093038, (ChEESE-CoE).
Peer Reviewed
Postprint (published version)
13 p.
eng
Attribution 4.0 International
http://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Enginyeria civil::Geologia::Riscos geològics
Volcanic activity prediction
Activitat volcànica -- Previsió
Uncertainties, complexities and possible forecasting of Volcán de Colima energy emissions (Mexico, years 2013–2015) based on a fractal reconstruction theorem
Article
https://npg.copernicus.org/articles/30/571/2023/
Barcelona Supercomputing Center
info:eu-repo/grantAgreement/EC/HE/101093038/EU/Center of Excellence for Exascale in Solid Earth/ChEESE-2P
37862209
Monterrubio, M.; Lana, F.J.; Arámbula-Mendoza, R.
Nonlinear processes in geophysics
30
4
571
583
eprints
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3728142023-10-15T00:49:58Zcom_2117_79677com_2117_28579com_2117_28577com_2117_98851com_2117_28581com_2117_3989com_2117_80515com_2117_23714com_2117_28578com_2117_15797col_2117_79695col_2117_103655col_2117_3990col_2117_80523col_2117_3055openAccess
Eiximeno Franch, Benet
Miró Jané, Arnau
Cajas García, Juan Carlos
Lehmkuhl Barba, Oriol
Rodríguez Pérez, Ivette María
Universitat Politècnica de Catalunya. Departament de Física
Universitat Politècnica de Catalunya. Departament de Màquines i Motors Tèrmics
Barcelona Supercomputing Center
Universitat Politècnica de Catalunya. TUAREG - Turbulence and Aerodynamics in Mechanical and Aerospace Engineering Research Group
2022-09-15T06:26:53Z
2022-09-15T06:26:53Z
2022-09-02
Eiximeno, B. [et al.]. On the wake dynamics of an oscillating cylinder via proper orthogonal decomposition. "Fluids", 2 Setembre 2022, vol. 7, núm. 9, article 292, p. 1-23.
2311-5521
http://hdl.handle.net/2117/372814
10.3390/fluids7090292
The coherent structures and wake dynamics of a two-degree-of-freedom vibrating cylinder with a low mass ratio at Re=5300 are investigated by means of proper orthogonal decomposition (POD) of a numerical database generated using large-eddy simulations. Two different reduced velocities of U*=3.0 and U*=5.5, which correspond with the initial and super-upper branches, are considered. This is the first time that this kind of analysis is performed in this kind of system in order to understand the role of large coherent motions on the amplification of the forces. In both branches of response, almost 1000 non-correlated in-time velocity fields have been decomposed using the snapshot method. It is seen that a large number of modes is required to represent 95% of the turbulent kinetic energy of the flow, but the first two modes contain a large percentage of the energy as they represent the wake large-scale vortex tubes. The energy dispersion of the high-order modes is attributed to the cylinder movement in the inline and cross-stream directions. Substantially different POD modes have been found in the two branches. While the first six modes resemble those observed in the static cylinder or in the initial branch of a one-degree of freedom cylinder in the initial branch, the modes not only contain information about the wake vortexes in the super-upper branch but also about the formation of the 2T vortex pattern and the Taylor–Görtler structures. It is shown that the 2T vortex pattern is formed by the interplay between the Taylor–Görtler stream-wise vortical structures and the cylinder movement and is responsible for the increase in the lift force and larger elongation in the super-upper branch.
This work has been partially financially supported by the Ministerio de Economía, Industria y Competitividad, Secretaría de Estado de Investigación, Desarrollo e Innovación, Spain (Ref. PID2020-116937RB-C21, PID2020-116937RB-C22), and by the European High-Performance Computing Joint Undertaking (JU) under grant agreement No 956104. The JU receives support from the European Union’s Horizon 2020 research and innovation programme and Spain, France, Germany. O. Lehmkuhl work is financed by a Ramón y Cajal postdoctoral contract by the Ministerio de Economía y Competitividad, Secretaría de Estado de Investigación, Desarrollo e Innovación, Spain (RYC2018-025949-I).
Peer Reviewed
Postprint (published version)
23 p.
eng
Multidisciplinary Digital Publishing Institute (MDPI)
Attribution 4.0 International
http://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Enginyeria mecànica::Mecànica de fluids
Cylinders
Wakes (Fluid dynamics)
LES
Two-degrees-of-freedom vibrating cylinder
POD
Coherent structures
Cilindres
Dinàmica de fluids
On the wake dynamics of an oscillating cylinder via proper orthogonal decomposition
Article
https://www.mdpi.com/2311-5521/7/9/292
info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PID2020-116937RB-C21/ES/ALGORITMOS DE INTELIGENCIA ARTIFICIAL Y COMPUTACION DE ALTAS PRESTACIONES PARA MODELADO DE TURBULENCIA, CONTROL DE FLUJO Y AEROACUSTICA./
info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PID2020-116937RB-C22/ES/TOWARDS REAL-TIME ACTUATION STRATEGIES FOR FLOW CONTROL AND NOISE REDUCTION IN AIRCRAFTS./
info:eu-repo/grantAgreement/EC/H2020/956104/EU/CODA: Next generation of industrial aerodynamic simulation code/NextSim
34213133
Eiximeno, B.; Miró, A.; Cajas, J.; Lehmkuhl , O.; Rodríguez, I.
Fluids
7
9, article 292
1
23
eprints
10.13039/501100011033
Agencia Estatal de Investigación
10.13039/501100011033
Agencia Estatal de Investigación
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3969552023-11-23T15:00:17Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Kirov, Krassimir K
Challis, Clive D
la Luna, Elena de
Eriksson, Jacob
Gallart, Daniel
Mantsinen, Mervi
Barcelona Supercomputing Center
2023-11-23T14:54:51Z
2023-11-23T14:54:51Z
2023
Kirov, K.K. [et al.]. Impact of RF waves – fast NBI ions interaction on the fusion performance in JET DTE2 campaign. "Nuclear Fusion", 2023,
1741-4326
http://hdl.handle.net/2117/396955
10.1088/1741-4326/ad0dd5
This work studies the interaction between Radio Frequency (RF) waves used for Ion Cyclotron Resonance Heating (ICRH) and the fast Deuterium (D) and Tritium (T) Neutral Beam Injected (NBI) ions in DT plasma. The focus is on the effect of this interaction, also referred to as synergistic effects, on the fusion performance in the recent JET DTE2 campaign. Experimental data from dedicated pulses at 3.43T/2.3MA heated at (i) 51.4MHz giving central minority H and n=2 D and at (ii) 32.2MHz for central minority 3He and n=2 T resonances were analyzed and conclusions were drawn and supported by modelling of the synergistic effects. TRANSP runs with and without RF kick operator predicted moderate increase, about 10%, in DT rates for the case of RF wave - fast D NBI ions interactions at n=2 harmonic of ion cyclotron resonance and negligible impact by synergistic interaction between fast T NBI ions and RF waves. JETTO modelling gives 29% enhancement of fusion rates due to RF waves – fast D NBI ions interaction and 18% enhancement for fast T NBI ions. Analysis of experimental neutron rates compared to TRANSP predictions without synergistic effects and Magnetic Proton Recoil (MPRu) neutron spectrometer indicate approximately 25-28% enhancement of fusion rates due to RF interaction with fast D ions and approximately 5-8% when RF wave – fast T NBI ions interaction is taking place. Contribution of various heating and fast ion sources have been assessed and discussed.
}
This work has been carried out within the framework of the EUROfusion Consortium, funded by the
European Union via the Euratom Research and Training Programme (Grant Agreement No 101052200 —
EUROfusion) and from the EPSRC [grant number EP/W006839/1]. To obtain further information on the
data and models underlying this paper please contact PublicationsManager@ukaea.uk . Views and opinions
expressed are however those of the author(s) only and do not necessarily reflect those of the European
Union or the European Commission. Neither the European Union nor the European Commission can be
held responsible for them.
Peer Reviewed
Postprint (published version)
"Article signat per 23 autors/es: Krassimir K Kirov, Clive D Challis, Elena de la Luna, Jacob Eriksson, Daniel Gallart, Jeronimo Garcia, Marina Gorelenkova, Joerg Hobirk, Philippe Jacquet, Athina Kappatou, Yevgen Kazakov, David Keeling, Damian King, Ernesto A Lerche, Costanza F Maggi, Joelle Mailloux, Paola Mantica, Mervi Mantsinen, Mikhail Maslov, Sheena Menmuir, Paula Sirén, Žiga Štancar and Dirk Van Eester"
eng
IOP Publishing
Attribution 4.0 International
http://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Informàtica::Aplicacions de la informàtica::Aplicacions informàtiques a la física i l‘enginyeria
Plasma heating
Tokamaks
RF waves
JET DTE2
Ion Cyclotron Resonance Heating (ICRH)
Simulació per ordinador
Impact of RF waves – fast NBI ions interaction on the fusion performance in JET DTE2 campaign
Article
https://iopscience.iop.org/article/10.1088/1741-4326/ad0dd5
info:eu-repo/grantAgreement/EC/HE/101052200/EU/Implementation of activities described in the Roadmap to Fusion during Horizon Europe through a joint programme of the members of the EUROfusion consortium/EUROfusion
Nuclear Fusion
eprints
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3836832023-02-19T20:02:14Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Gonzalez Martin, Pablo
Sacco, Federica
Butakoff, Constantine
Doste, Ruben
Bederian, Carlos
Houzeaux, Guillaume
Vázquez, Mariano
Aguado Sierra, Jazmín
Barcelona Supercomputing Center
2023-02-17T16:23:10Z
2023-02-17T16:23:10Z
2023
Gonzalez Martin, P. [et al.]. Ventricular anatomical complexity and sex differences impact predictions from electrophysiological computational models. "PLoS ONE", 2023, vol. 18, núm. 2, e0263639.
1932-6203
http://hdl.handle.net/2117/383683
The aim of this work was to analyze the influence of sex hormones and anatomical details (trabeculations and false tendons) on the electrophysiology of healthy human hearts. Additionally, sex- and anatomy-dependent effects of ventricular tachycardia (VT) inducibility are presented. To this end, four anatomically normal, human, biventricular geometries (two male, two female), with identifiable trabeculations, were obtained from high-resolution, ex-vivo MRI and represented by detailed and smoothed geometrical models (with and without the trabeculations). Additionally one model was augmented by a scar. The electrophysiology finite element model (FEM) simulations were carried out, using O’Hara-Rudy human myocyte model with sex phenotypes of Yang and Clancy. A systematic comparison between detailed vs smooth anatomies, male vs female normal hearts was carried out. The heart with a myocardial infarction was subjected to a programmed stimulus protocol to identify the effects of sex and anatomical detail on ventricular tachycardia inducibility. All female hearts presented QT-interval prolongation however the prolongation interval in comparison to the male phenotypes was anatomy-dependent and was not correlated to the size of the heart. Detailed geometries showed QRS fractionation and increased T-wave magnitude in comparison to the corresponding smoothed geometries. A variety of sustained VTs were obtained in the detailed and smoothed male geometries at different pacing locations, which provide evidence of the geometry-dependent differences regarding the prediction of the locations of reentry channels. In the female phenotype, sustained VTs were induced in both detailed and smooth geometries with RV apex pacing, however no consistent reentry channels were identified. Anatomical and physiological cardiac features play an important role defining risk in cardiac disease. These are often excluded from cardiac electrophysiology simulations. The assumption that the cardiac endocardium is smooth may produce inaccurate predictions towards the location of reentry channels in in-silico tachycardia inducibility studies
JA-S, FS, GH and MV are supported by the European Union’s Horizon 2020 research and innovation programme under grant agreements No 675451 (Compbiomed project phase 1) and No 823712 (CompBioMed project, phase 2) and project No 777204 (SilicoFCM project). Part of the simulation computing hours were provided by the CompBioMed project phase 1. JA-S was awarded computation time from Red Espanola de Supercomputacion (RES). (Activity IDs: FI-2018-2-0049 and BCV-2019-2-0014) JA-S is funded by a Ramon y Cajal fellowship (RYC-2017-22532), Ministerio de Ciencia e Innovacion, Spain; and by Plan Estatal de Investigacion Cientifica y Tecnica y de Innovacion 2017-2020 from the Ministerio de Ciencia e Innovacion y Universidades (PID2019-104356RBC41/AEI/10.13039/501100011033): meHeart ME PID2019-104356RB-C44. CB is funded by the Torres Quevedo Program (PTQ2018-010290), Ministerio de Ciencia e Innovacion, Spain. MV, GH and CB are funded by the Spanish Neotec project EXP - 00123159/SNEO-20191113 Generador de corazones virtuales. LKGM was funded by Fundacion Carolina-BBVA. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. There was no additional external funding received for this study.
Peer Reviewed
Postprint (published version)
"Article signat per 11 autors/es: Pablo Gonzalez-Martin,Federica Sacco,Constantine Butakoff,Ruben Doste,Carlos Bederian,Lilian K. Gutierrez Espinosa de los Monteros,Guillaume Houzeaux,Paul A. Iaizzo,Tinen L. Iles,Mariano Vazquez,Jazmin Aguado-Sierra"
eng
Public Library of Science
Attribution 4.0 International
http://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Informàtica::Aplicacions de la informàtica::Aplicacions informàtiques a la física i l‘enginyeria
Personalized medicine
Imaging
Personalized medicine
Ventricle
Computational cardiac models
sex-specific cardiac pathophysiology
Simulació per ordinador
Ventricular anatomical complexity and sex differences impact predictions from electrophysiological computational models
Article
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0263639
info:eu-repo/grantAgreement/EC/H2020/675451/EU/A Centre of Excellence in Computational Biomedicine/CompBioMed
info:eu-repo/grantAgreement/EC/H2020/823712/EU/A Centre of Excellence in Computational Biomedicine/CompBioMed2
info:eu-repo/grantAgreement/EC/H2020/777204/EU/In Silico trials for drug tracing the effects of sarcomeric protein mutations leading to familial cardiomyopathy/SILICOFCM
The high resolution images of all heart anatomies are available at the Visible Heart® Laboratory Atlas website (Heart Database: http://www.vhlab.umn.edu/atlas/histories/histories.shtml). The DICOM datasets were obtained by MRI scanning of perfusion fixed hearts that were graciously donated by the organ donors and their families through LifeSource. The datasets are available upon request at Visible Heart Laboratory (http://www.vhlab.umn.edu/) after signing an agreement. Alya is a source-available software and can be made available under an agreement (https://www.bsc.es/research-and-development/software-and-apps/software-list/alya). The mathematical model to produce the fiber field is openly available in github (https://github.com/rdoste/OT_RBM). The methodology here presented can be replicated using any finite element solver given all of the parameterization information provided within this paper.
e0263639
PLoS ONE
18
2
eprints
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3759482023-10-09T07:58:27Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Chen, Cheng
Mira Martínez, Daniel
Xing, Zhihao
Jiang, Xi
Barcelona Supercomputing Center
2022-11-09T16:47:40Z
2022-11-09T16:47:40Z
2022
Chen, C. [et al.]. Thermophysical property prediction of biodiesel mixtures at extreme conditions using molecular dynamics simulation. "Journal of Molecular Liquids", 2022, vol. 367, núm. Part B, 120423.
0167-7322
1873-3166
http://hdl.handle.net/2117/375948
10.1016/j.molliq.2022.120423
Liquid biofuels such as biodiesel are playing an increasing role in renewable energy utilisation, but accurate predictions of fuel properties at extreme conditions remain challenging. In this study, molecular dynamics (MD) simulation with classical force field is performed to obtain the thermophysical properties of biodiesel over extended ranges of temperatures and pressures. The predicted properties include the critical temperature, critical density, critical pressure, surface tension, viscosity, thermal conductivity and diffusion coefficient. The specific MD setup for fuel thermophysical property prediction is examined. It is observed that the long-range dispersion interaction is essential to accurately predicting the surface tension, and averaging over a sufficient number of independent replication simulations is required to eliminate the statistical error when using the Green-Kubo method for viscosity calculation. The reliability of MD approach is validated against experimental data at normal temperature and pressure. The equilibrium MD simulation has an advantage over nonequilibrium MD simulation when building databases of fuel properties. Moreover, the properties of biodiesel are compared with conventional diesel to elucidate the effects of fuel composition and molecular structure of the fuel surrogates on fuel thermophysical properties. For biodiesel utilisation, higher values of critical temperature, surface tension and viscosity, lower diffusivity together with the increased aggregation tendency in bath gas indicate the needs of further optimisation of injection system to achieve the desired mixing in combustion applications.
Peer Reviewed
Postprint (published version)
15 p.
eng
Attribution-NonCommercial 4.0 International
http://creativecommons.org/licenses/by-nc/4.0/
Open Access
Àrees temàtiques de la UPC::Informàtica::Aplicacions de la informàtica::Aplicacions informàtiques a la física i l‘enginyeria
Molecular dynamics
Biodiesel fuels.
Biodiesel
Thermophysical property
Supercritical conditions
Molecular dynamics
Simulació per ordinador
Thermophysical property prediction of biodiesel mixtures at extreme conditions using molecular dynamics simulation
Article
https://www.sciencedirect.com/science/article/pii/S0167732222019626
120423
Journal of Molecular Liquids
367
Part B
eprints
oai:upcommons.upc.edu:2117/1867092020-07-23T23:27:43Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Pons, Ramón
Cajas, Juan Carlos
Rodríguez-Palomares, José F.
Guala, Andrea
Dux-Santoy, Lydia
Teixidó-Tura, Gisela
Molins, José Javier
Vázquez, Mariano
Evangelista, Arturo
Martorell, Jordi
Barcelona Supercomputing Center
2020-05-07T13:24:54Z
2020-05-07T13:24:54Z
2020-02
Pons, R. [et al.]. Fluid–structure interaction simulations outperform computational fluid dynamics in the description of thoracic aorta haemodynamics and in the differentiation of progressive dilation in Marfan syndrome patients. "Royal Society Open Science", Febrer 2020, vol. 7, núm. 2, 191752.
2054-5703
http://hdl.handle.net/2117/186709
10.1098/rsos.191752
Abnormal fluid dynamics at the ascending aorta may be at the origin of aortic aneurysms. This study was aimed at comparing the performance of computational fluid dynamics (CFD) and fluid–structure interaction (FSI) simulations against four-dimensional (4D) flow magnetic resonance imaging (MRI) data; and to assess the capacity of advanced fluid dynamics markers to stratify aneurysm progression risk. Eight Marfan syndrome (MFS) patients, four with stable and four with dilating aneurysms of the proximal aorta, and four healthy controls were studied. FSI and CFD simulations were performed with MRI-derived geometry, inlet velocity field and Young's modulus. Flow displacement, jet angle and maximum velocity evaluated from FSI and CFD simulations were compared to 4D flow MRI data. A dimensionless parameter, the shear stress ratio (SSR), was evaluated from FSI and CFD simulations and assessed as potential correlate of aneurysm progression. FSI simulations successfully matched MRI data regarding descending to ascending aorta flow rates (R2 = 0.92) and pulse wave velocity (R2 = 0.99). Compared to CFD, FSI simulations showed significantly lower percentage errors in ascending and descending aorta in flow displacement (−46% ascending, −41% descending), jet angle (−28% ascending, −50% descending) and maximum velocity (−37% ascending, −34% descending) with respect to 4D flow MRI. FSI- but not CFD-derived SSR differentiated between stable and dilating MFS patients. Fluid dynamic simulations of the thoracic aorta require fluid–solid interaction to properly reproduce complex haemodynamics. FSI- but not CFD-derived SSR could help stratifying MFS patients.
This study was funded by Ministerio de Economía y Competitividad (grant no. RTC-2016-5152-1), Fundació la Marató de TV3 (grant no. 20151330), FP7 People: Marie-Curie Actions (grant no. 267128), Instituto de Salud Carlos III (grant nos PI14/0106 and PI17/00381) and ‘la Caixa’ Foundation. M.V. was funded by CompBioMed2, grant agreement ID: 823712, funded under: H2020-EU.1.4.1.3; and SILICOFCM, grant agreement ID: 777204, funded under: H2020-EU.3.1.5.
Peer Reviewed
Postprint (published version)
13 p.
eng
The Royal Society
Attribution 3.0 Spain
Attribution 4.0 International (CC BY 4.0)
http://creativecommons.org/licenses/by/3.0/es/
https://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Ciències de la salut::Medicina
Magnetic resonance imaging
Computational fluid dynamics
Marfan syndrome
Fluid-structure interaction
Aneurysms
Ascending aorta
Aneurysm
Marfan syndrome
Computational fluid dynamic
Fluid–structure interaction
Shear stress rati
Imatges per ressonància magnètica
Dinàmica de fluids computacional
Aneurismes
Eight Marfan syndrome
Fluid–structure interaction simulations outperform computational fluid dynamics in the description of thoracic aorta haemodynamics and in the differentiation of progressive dilation in Marfan syndrome patients
Article
https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.191752
info:eu-repo/grantAgreement/EC/H2020/823712/EU/A Centre of Excellence in Computational Biomedicine/CompBioMed2
info:eu-repo/grantAgreement/EC/H2020/777204/EU/In Silico trials for drug tracing the effects of sarcomeric protein mutations leading to familial cardiomyopathy/SILICOFCM
191752
Royal Society Open Science
7
2
eprints
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3527022021-10-03T21:22:40Zcom_2117_3911com_2117_28579com_2117_28577com_2117_80515com_2117_23714com_2117_28578com_2117_15797col_2117_3912col_2117_80523col_2117_3055openAccess
Cox, Simon J. D.
González Beltran, Alejandra N.
Magagna, Barbara
Marinescu, Maria Cristina
Universitat Politècnica de Catalunya. Departament d'Arquitectura de Computadors
Barcelona Supercomputing Center
2021-09-30T06:40:35Z
2021-09-30T06:40:35Z
2021-06-16
Cox, S. [et al.]. Ten simple rules for making a vocabulary FAIR. "PLoS computational biology", 16 Juny 2021, vol. 17, núm. 6, p. 1-15.
1553-7358
http://hdl.handle.net/2117/352702
10.1371/journal.pcbi.1009041
We present ten simple rules that support converting a legacy vocabulary—a list of terms available in a print-based glossary or in a table not accessible using web standards—into a FAIR vocabulary. Various pathways may be followed to publish the FAIR vocabulary, but we emphasise particularly the goal of providing a globally unique resolvable identifier for each term or concept. A standard representation of the concept should be returned when the individual web identifier is resolved, using SKOS or OWL serialised in an RDF-based representation for machine-interchange and in a web-page for human consumption. Guidelines for vocabulary and term metadata are provided, as well as development and maintenance considerations. The rules are arranged as a stepwise recipe for creating a FAIR vocabulary based on the legacy vocabulary. By following these rules you can achieve the outcome of converting a legacy vocabulary into a standalone FAIR vocabulary, which can be used for unambiguous data annotation. In turn, this increases data interoperability and enables data integration.
The contribution of SJDC was supported through a CSIRO Strategic Project for engagement with CODATA. The contribution of BM was supported through - eLTERplus, a project funded from the INFRAIA-01-2018-2019 programme of European Union’s Horizon 2020 research and innovation programme under grant agreement No 871128 - OBARIS, an FFG funded project (No 887389).
Peer Reviewed
Postprint (published version)
15 p.
eng
Public Library of Science (PLOS)
Attribution 4.0 International
https://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Informàtica::Intel·ligència artificial::Representació del coneixement
Knowledge representation (Information theory)
Metadata
Ontologies (Information retrieval)
Legacy vocabulary
Distinct IRI
FAIR vocabulary
SKOS
OWL
RDF-based representation
Representació del coneixement (Teoria de la informació)
Metadades
Ontologies (Informàtica)
Ten simple rules for making a vocabulary FAIR
Article
https://journals.plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.1009041
32062423
Cox, S.; González, A.; Magagna, B.; Marinescu, M.
PLoS computational biology
17
6
1
15
eprints
oai:upcommons.upc.edu:2117/3437582022-05-17T10:08:36Zcom_2117_3486com_2117_28581com_2117_28577com_2117_3971com_2117_28579com_2117_80515com_2117_23714com_2117_28578com_2117_15797col_2117_3487col_2117_3972col_2117_80523col_2117_3055openAccess
Corral Cano, Álvaro
Serra Mochales, Isabel
Ferrer Cancho, Ramon
Universitat Politècnica de Catalunya. Departament de Ciències de la Computació
Barcelona Supercomputing Center
Universitat Politècnica de Catalunya. LARCA - Laboratori d'Algorísmia Relacional, Complexitat i Aprenentatge
2021-04-15T06:47:26Z
2021-04-15T06:47:26Z
2020-11-10
Corral, Á.; Serra, I.; Ferrer-i-Cancho, R. Distinct flavors of Zipf's law and its maximum likelihood fitting: Rank-size and size-distribution representations. "Physical review E", 10 Novembre 2020, vol. 102, núm. 5, article 052113, p. 1-17.
2470-0053
http://hdl.handle.net/2117/343758
10.1103/PhysRevE.102.052113
In recent years, researchers have realized the difficulties of fitting power-law distributions properly. These difficulties are higher in Zipfian systems, due to the discreteness of the variables and to the existence of two representations for these systems, i.e., two versions depending on the random variable to fit: rank or size. The discreteness implies that a power law in one of the representations is not a power law in the other, and vice versa. We generate synthetic power laws in both representations and apply a state-of-the-art fitting method to each of the two random variables. The method (based on maximum likelihood plus a goodness-of-fit test) does not fit the whole distribution but the tail, understood as the part of a distribution above a cutoff that separates non-power-law behavior from power-law behavior. We find that, no matter which random variable is power-law distributed, using the rank as the random variable is problematic for fitting, in general (although it may work in some limit cases). One of the difficulties comes from recovering the “hidden” true ranks from the empirical ranks. On the contrary, the representation in terms of the distribution of sizes allows one to recover the true exponent (with some small bias when the underlying size distribution is a power law only asymptotically).
Support from projects FIS2012-31324, FIS2015-71851-P, TIN2017-89244-R, PGC-FIS2018-099629-B-I00, María de Maeztu Program MDM-2014-0445, from Spanish MINECO; 2014SGR-1307, 2017SGR-856 (MACDA) from AGAUR; and the Collaborative Mathematics Project from Fundación La Caixa (I.S.) is acknowledged.
Peer Reviewed
Postprint (author's final draft)
17 p.
eng
American Institute of Physics (AIP)
Àrees temàtiques de la UPC::Matemàtiques i estadística::Estadística matemàtica
Àrees temàtiques de la UPC::Informàtica::Informàtica teòrica
Graph theory
Zipf’s law
Statistical inference
Scaling in socio-economic systems
Grafs, Teoria de
Zipf's, Llei de
Distinct flavors of Zipf's law and its maximum likelihood fitting: Rank-size and size-distribution representations
Article
https://journals.aps.org/pre/abstract/10.1103/PhysRevE.102.052113
info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016/TIN2017-89244-R/ES/GESTION Y ANALISIS DE DATOS COMPLEJOS/
Open Access
30001211
Corral, Á.; Serra, I.; Ferrer-i-Cancho, R.
Physical review E
102
5, article 052113
1
17
eprints
10.13039/501100011033
Agencia Estatal de Investigación
oai:upcommons.upc.edu:2117/3646362022-03-27T15:52:00Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Kalha, Curran
Ratcliff, Laura
Gutierrez Moreno, Jose Julio
Mohr, Stephan
Mantsinen, Mervi
Barcelona Supercomputing Center
2022-03-21T15:05:28Z
2022-03-21T15:05:28Z
2022-01
Kalha, C. [et al.]. Lifetime effects and satellites in the photoelectron spectrum of tungsten metal. "Physical Review B", 2022, vol. 105, 045129.
2469-9950
2469-9969
http://hdl.handle.net/2117/364636
10.1103/PhysRevB.105.045129
Tungsten (W) is an important and versatile transition metal and has a firm place at the heart of many technologies. A popular experimental technique for the characterization of tungsten and tungsten-based compounds is x-ray photoelectron spectroscopy (XPS), which enables the assessment of chemical states and electronic structure through the collection of core level and valence band spectra. However, in the case of tungsten metal, open questions remain regarding the origin, nature, and position of satellite features that are prominent in the photoelectron spectrum. These satellites are a fingerprint of the electronic structure of the material and have not been thoroughly investigated, at times leading to their misinterpretation. The present work combines high-resolution soft and hard x-ray photoelectron spectroscopy (SXPS and HAXPES) with reflected electron energy loss spectroscopy (REELS) and a multitiered ab initio theoretical approach, including density functional theory (DFT) and many-body perturbation theory (G0W0 and
GW
+
C
), to disentangle the complex set of experimentally observed satellite features attributed to the generation of plasmons and interband transitions. This combined experiment-theory strategy is able to uncover previously undocumented satellite features, improving our understanding of their direct relationship to tungsten's electronic structure. Furthermore, it lays the groundwork for future studies into tungsten-based mixed-metal systems and holds promise for the reassessment of the photoelectron spectra of other transition and post-transition metals, where similar questions regarding satellite features remain.
CK acknowledges the support from the Department of Chemistry, UCL. NKF acknowledges support from the Engineering and Physical Sciences Research Council (EP/L015277/1). AR acknowledges the support fromthe Analytical Chemistry Trust Fund for her CAMS-UK Fellowship. LER acknowledges support from an EPSRC Early Career Research Fellowship (EP/P033253/1). JL and JMK acknowledge funding from EPSRC under Grant No. EP/R002010/1 and from a Royal Society University Research Fellowship (URF/R/191004). This work used the ARCHER UK National Supercomputing Service via JL’s membership of the HEC Materials Chemistry Consortium of UK, which is funded by EPSRC
(EP/L000202). JJGM and SM acknowledge the support from the FusionCAT project (001-P-001722) cofinanced by the European Union Regional Development Fund within the framework of the ERDF Operational Program of Catalonia 2014-2020 with a grant of 50% of total cost eligible, the access to computational resources at MareNostrum and the technical support provided by BSC (RES-QS-2020-3-0026). Part of this work was carried out using supercomputer resources provided under the EU-JA Broader Approach collaboration in the Computational Simulation Centre of International Fusion Energy Research Centre (IFERC-CSC)
Peer Reviewed
Postprint (author's final draft)
"Article signat per 13 autors/es: C. Kalha, L. E. Ratcliff, J. J. Gutiérrez Moreno, S. Mohr, M. Mantsinen, N. K. Fernando, P. K. Thakur, T.-L. Lee, H.-H. Tseng, T. S. Nunney, J. M. Kahk, J. Lischner, and A. Regoutz"
eng
American Physical Society
Àrees temàtiques de la UPC::Informàtica::Aplicacions de la informàtica::Aplicacions informàtiques a la física i l‘enginyeria
Condensed matter
X-ray photoelectron spectroscopy
Tungsten metal
X-ray photoelectron spectroscopy (XPS)
Photoelectron spectrum
Satellite
Metalls
Lifetime effects and satellites in the photoelectron spectrum of tungsten metal
Article
https://journals.aps.org/prb/abstract/10.1103/PhysRevB.105.045129
Open Access
045129
Physical Review B
105
eprints
oai:upcommons.upc.edu:2117/1104912022-05-17T10:08:36Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Gargallo-Peiró, Abel
Houzeaux, Guillaume
Roca, Xevi
Barcelona Supercomputing Center
2017-11-13T14:37:23Z
2017-11-13T14:37:23Z
2017
Gargallo-Peiró, A.; Houzeaux, G.; Roca, X. Subdividing triangular and quadrilateral meshes in parallel to approximate curved geometries. "Procedia Engineering", 2017, vol. 203, p. 310-322.
1877-7058
http://hdl.handle.net/2117/110491
10.1016/j.proeng.2017.09.814
A parallel distributed approach to refine a mesh while preserving the curvature of a target geometry is presented. Our approach starts by generating a coarse linear mesh of the computational domain. Second, the former coarse mesh is curved to match the curvature of the target geometry. Then, the curved mesh is partitioned and the subdomain meshes are sent to the slaves. Finally, the curved elements are uniformly subdivided in parallel targeting the geometry approximated by the curved mesh. The result is a distributed finer linear mesh featuring improved geometric accuracy. The key ingredient of our implementation is to approximate the target geometry as a linear mesh equipped with an elemental field corresponding to an element-wise polynomial geometry representation. Thus, the distribution of the curved geometry is equivalent to partitioning the linear mesh and sending the subdomain meshes and the elemental fields to the slaves. The main application of the obtained finer linear mesh is to compute in parallel steady state flow solutions on real topographies. The qualitative results show that for 2D and 3D steady state flow solutions, on real and synthetic topographies, our parallel subdivision approach mitigates the artificial artifacts that might appear with standard straight-sided subdivision methods. We also check the parallel performance of the implementation by performing a weak scalability test in 2D.
This work was financially supported by the PRACE project funded in part by the EUs Horizon 2020 research and innovation program (2014-2020) under grant agreement 653838. This project has received funding from the European Research Council (ERC) under the European Unions Horizon 2020 research and innovation programme under grant agreement No 715546. The work of the corresponding author has been partially supported by the Spanish Ministerio
de Economía y Competitividad under the personal grant agreement RYC- 2015-01633.
Peer Reviewed
Postprint (published version)
13 p.
eng
Elsevier
Attribution-NonCommercial-NoDerivs 3.0 Spain
http://creativecommons.org/licenses/by-nc-nd/3.0/es/
Open Access
Àrees temàtiques de la UPC::Enginyeria elèctrica
Parallel processing (Electronic computers)
Mesh subdivision
Mesh multiplication
Parallel mesh generation
Parallel computing
High-order mesh
Processament en paral·lel (Ordinadors)
Subdividing triangular and quadrilateral meshes in parallel to approximate curved geometries
Article
http://www.sciencedirect.com/science/article/pii/S1877705817343771
info:eu-repo/grantAgreement/EC/H2020/653838/EU/PRACE 4th Implementation Phase Project/PRACE-4IP
info:eu-repo/grantAgreement/EC/H2020/715546/EU/Best Curved Adapted Meshes for Space-Time Flow Simulations/Tesseract
info:eu-repo/grantAgreement/MINECO/PE2013-2016/RYC-2015-01633
26th International Meshing Roundtable, IMR26, 18-21 September 2017, Barcelona, Spain
Procedia Engineering
203
310
322
eprints
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3282132021-11-16T01:26:19Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Plagianakos, Theofanis S.
Muñoz, Kirsa
Guillamet, Gerard
Prentzias, Vasileios
Quintanas-Corominas, Adrià
Jimenez, Miguel
Karachalios, Evangelos
Barcelona Supercomputing Center
2020-08-05T15:03:36Z
2021-11-16T01:26:19Z
2020-02-01
Plagianakos, T.S. [et al.]. Assessment of CNT-doping and hot-wet storage aging effects on Mode I, II and I/II interlaminar fracture toughness of a UD Graphite/Epoxy material system. "Engineering Fracture Mechanics", 1 Febrer 2020, vol. 224, 106761.
0013-7944
http://hdl.handle.net/2117/328213
10.1016/j.engfracmech.2019.106761
The interlaminar fracture toughness of two unidirectional Graphite/Epoxy composite material systems has been experimentally assessed. The systems studied were prepreg composite and prepreg composite treated with carbon nanotubes (CNT). The fracture toughness has been quantified in Mode I, Mode II and Mode I/II by performing DCB, ENF and MMB tests according to relevant ISO and ASTM standards. The effect of aging by storage under hot-wet conditions has been quantified by studying these systems at room temperature without aging and at 70 °C after aging treatment. Experimental data are reported in a 3- or 5-specimen batch mode, indicating non-linear behavior and sensitivity to imperfections in coupons alignment and load application. Moreover, intermediate variables required for the estimation of fracture toughness are presented in order to be used as a reference guide for principal fracture test data evaluation. In the case of the RT systems, measured data have been compared with analytical solutions and finite element model predictions yielding good correlation for DCB and ENF tests and considerable deviation in the case of MMB tests. Main findings include that CNT-doping leads to an increase of fracture toughness in all modes, especially in Mode II, and that aging leads to less variation in measurements for both systems, indicating a more uniform matrix response.
The current work has received funding from EU Horizon 2020 Clean Sky II project SHERLOC (Structural Health Monitoring, Manufacturing and Repair Technologies for Life Management of Composite Fuselage) under Grant Agreement No CS2-AIR-GAM-2014-2015-01. The authors from HAI would like to thank our ex-colleagues Dimitrios Habas and Stavros Kalogeropoulos for their major assistance with coupons fabrication and experimental work, respectively.
Peer Reviewed
Postprint (author's final draft)
40 p.
eng
Elsevier
Attribution-NonCommercial-NoDerivs 3.0 Spain
Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)
http://creativecommons.org/licenses/by-nc-nd/3.0/es/
https://creativecommons.org/licenses/by-nc-nd/4.0/
Open Access
Àrees temàtiques de la UPC::Informàtica::Aplicacions de la informàtica::Aplicacions informàtiques a la física i l‘enginyeria
Computer simulation
Composite materials--Mechanical properties
Carbon nanotubes
Graphite/Epoxy composite material systems
Aging of materials
Fracture toughness testing
Carbon nanotubes
Delamination
ASTM standards
Composite Laminates
Simulació per ordinador
Composites
Assessment of CNT-doping and hot-wet storage aging effects on Mode I, II and I/II interlaminar fracture toughness of a UD Graphite/Epoxy material system
Article
https://www.sciencedirect.com/science/article/abs/pii/S0013794419308951
info:eu-repo/grantAgreement/EC/H2020/807083/EU/AIRFRAME ITD/GAM AIR 2018
106761
Engineering Fracture Mechanics
224
eprints
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3852182024-02-04T01:49:41Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577com_2117_184556com_2117_184544com_2117_15797col_2117_80523col_2117_184725col_2117_3055
Surapaneni, Anurag
Mira Martínez, Daniel
Universitat Politècnica de Catalunya. Doctorat en Ciència i Tecnologia Aeroespacials
Barcelona Supercomputing Center
2023-03-20T14:25:19Z
2023-05
2025-03-15
Surapaneni, A.; Mira, D. Assessment of dynamic adaptive chemistry with tabulated reactions for the simulation of unsteady multiregime combustion phenomena. "Combustion and flame", Maig 2023, vol. 251, article 112715, p. 1-15.
0010-2180
http://arxiv.org/abs/2303.10040
http://hdl.handle.net/2117/385218
10.1016/j.combustflame.2023.112715
Solving chemistry is an integral part of reacting flow simulations, usually dominating the computational cost. Among the different strategies to accelerate the solution of chemistry and to achieve realizable simulations, the use of Dynamic Adaptive Chemistry (DAC) stands out among other methods. DAC methods are based on the use of reduced mechanisms generated from local conditions. The reduction process is computationally expensive and strategies for reducing the frequency of reduction and the re-utilization of the generated reduced mechanisms are key in making DAC methods computationally affordable. In this study, a new method hereby referred as Tabulated Reactions for Adaptive Chemistry (TRAC) is proposed to correlate chemical states with their reduced mechanisms in order to reduce both the frequency of reduction and to allow for re-utilization of reduced chemical schemes. TRAC introduces a mechanism tabulation strategy based on the use of a low-dimensional space that defines the thermo-chemical conditions for which specific reduced reaction mechanisms are stored. Chemistry reduction is achieved by the use of Path Flux Analysis (PFA) with a reaction rate-sensitivity method to achieve further reduction in the reaction mechanisms. The new TRAC proposal is applied to various canonical transient problems and the results are compared with reference solutions obtained from detailed chemistry calculations. A speedup of about 4x was achieved with TRAC while maintaining an error under 3% in the prediction of the major and minor species, flame structure, and flame propagation.
This project has received funding from the European Research Council (ERC) under the European Unions Horizon 2020 research and innovation program (grant agreement No. 682383), the Center of Excellence in Combustion project (grant agreement No 952181), and the AHEAD PID2020-118387RB-C33 and ORION TRA2017-89139-C2-2-R projects from the Ministerio de Ciencia e Innovación. Anurag Surapaneni acknowledges the support from the Secretariat for Universities and Research of the Ministry of Business and Knowledge of the Government of Catalonia and the European Social Fund.
Peer Reviewed
Postprint (author's final draft)
15 p.
eng
Attribution-NonCommercial-NoDerivatives 4.0 International
http://creativecommons.org/licenses/by-nc-nd/4.0/
Restricted access - publisher's policy
Àrees temàtiques de la UPC::Aeronàutica i espai::Astronàutica::Enginyeria aeroespacial
Combustion
Dynamic adaptive chemistry
Chemistry reduction
Path flux analysis
Multiregime combustion
Combustió
Assessment of dynamic adaptive chemistry with tabulated reactions for the simulation of unsteady multiregime combustion phenomena
Article
https://www.sciencedirect.com/science/article/pii/S0010218023001001?via%3Dihub
info:eu-repo/grantAgreement/EC/H2020/682383/EU/Enabling Hydrogen-enriched burner technology for gas turbines through advanced measurement and simulation/HyBurn
info:eu-repo/grantAgreement/EC/H2020/952181/EU/Center of Excellence in Combustion/CoEC
info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PID2020-118387RB-C33/ES/CALCULO DE NUEVOS DESARROLLOS NUMERICOS PARA AHEAD/
info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016/TRA2017-89139-C2-2-R/ES/IMPLEMENTACION Y VALIDACION DE MODELOS HPC DE COMBUSTION Y EMISIONES PARA EL ANALISIS DE SISTEMAS DE TRANSPORTE SOSTENIBLES/
35608381
Surapaneni, A.; Mira, D.
Combustion and flame
251
article 112715
1
15
eprints
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
10.13039/501100011033
Agencia Estatal de Investigación
10.13039/501100011033
Agencia Estatal de Investigación
oai:upcommons.upc.edu:2117/3497132021-07-25T20:40:26Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Meyer, H.
Aguiam, D.
Angioni, C.
Albert, C.G.
Arden, N.
Mantsinen, Mervi
Schmitz, O.
Barcelona Supercomputing Center
2021-07-20T08:20:24Z
2021-07-20T08:20:24Z
2019
Meyer, H. [et al.]. Overview of physics studies on ASDEX Upgrade. "Nuclear Fusion", 2019, vol. 59, núm. 11, 112014.
0029-5515
1741-4326
http://hdl.handle.net/2117/349713
10.1088/1741-4326/ab18b8
The ASDEX Upgrade (AUG) programme, jointly run with the EUROfusion MST1 task force, continues to significantly enhance the physics base of ITER and DEMO. Here, the full tungsten wall is a key asset for extrapolating to future devices. The high overall heating power, flexible heating mix and comprehensive diagnostic set allows studies ranging from mimicking the scrape-off-layer and divertor conditions of ITER and DEMO at high density to fully non-inductive operation (q95 = 5.5, ) at low density. Higher installed electron cyclotron resonance heating power 6 MW, new diagnostics and improved analysis techniques have further enhanced the capabilities of AUG.
Stable high-density H-modes with MW m−1 with fully detached strike-points have been demonstrated. The ballooning instability close to the separatrix has been identified as a potential cause leading to the H-mode density limit and is also found to play an important role for the access to small edge-localized modes (ELMs). Density limit disruptions have been successfully avoided using a path-oriented approach to disruption handling and progress has been made in understanding the dissipation and avoidance of runaway electron beams. ELM suppression with resonant magnetic perturbations is now routinely achieved reaching transiently . This gives new insight into the field penetration physics, in particular with respect to plasma flows. Modelling agrees well with plasma response measurements and a helically localised ballooning structure observed prior to the ELM is evidence for the changed edge stability due to the magnetic perturbations. The impact of 3D perturbations on heat load patterns and fast-ion losses have been further elaborated.
Progress has also been made in understanding the ELM cycle itself. Here, new fast measurements of and Er allow for inter ELM transport analysis confirming that Er is dominated by the diamagnetic term even for fast timescales. New analysis techniques allow detailed comparison of the ELM crash and are in good agreement with nonlinear MHD modelling. The observation of accelerated ions during the ELM crash can be seen as evidence for the reconnection during the ELM. As type-I ELMs (even mitigated) are likely not a viable operational regime in DEMO studies of 'natural' no ELM regimes have been extended. Stable I-modes up to have been characterised using -feedback.
Core physics has been advanced by more detailed characterisation of the turbulence with new measurements such as the eddy tilt angle—measured for the first time—or the cross-phase angle of and fluctuations. These new data put strong constraints on gyro-kinetic turbulence modelling. In addition, carefully executed studies in different main species (H, D and He) and with different heating mixes highlight the importance of the collisional energy exchange for interpreting energy confinement. A new regime with a hollow profile now gives access to regimes mimicking aspects of burning plasma conditions and lead to nonlinear interactions of energetic particle modes despite the sub-Alfvénic beam energy. This will help to validate the fast-ion codes for predicting ITER and DEMO.
This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014–2018 and 2019–2020 under grant agreement No. 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission.
Postprint (published version)
"Article signat per més de 100 autors/es: H. Meyer, for the AUG Team: D. Aguiam, C. Angioni, C.G. Albert, N. Arden, R. Arredondo Parra, O. Asunta, M. de Baar, M. Balden, V. Bandaru, K. Behler, A. Bergmann, J. Bernardo, M. Bernert, A. Biancalani, R. Bilato, G. Birkenmeier, T.C. Blanken, V. Bobkov, A. Bock, T. Bolzonella, A. Bortolon, B. Böswirth, C. Bottereau, A. Bottino, H. van den Brand, S. Brezinsek, D. Brida, F. Brochard, C. Bruhn, J. Buchanan, A. Buhler, A. Burckhart, Y. Camenen, D. Carlton, M. Carr, D. Carralero, C. Castaldo, M. Cavedon, C. Cazzaniga, S. Ceccuzzi, C. Challis, A. Chankin, S. Chapman, C. Cianfarani, F. Clairet, S. Coda, R. Coelho, J.W. Coenen, L. Colas, G.D. Conway, S. Costea, D.P. Coster, T.B. Cote, A. Creely, G. Croci, G. Cseh, A. Czarnecka, I. Cziegler, O. D'Arcangelo, P. David, C. Day, R. Delogu, P. de Marné, S.S. Denk, P. Denner, M. Dibon, A. Di Siena, D. Douai, A. Drenik, R. Drube, M. Dunne, B.P. Duval, R. Dux, T. Eich, S. Elgeti, K. Engelhardt, B. Erdös, I. Erofeev, B. Esposito, E. Fable, M. Faitsch, U. Fantz, H. Faugel, I. Faust, F. Felici, J. Ferreira, S. Fietz, A. Figuereido, R. Fischer, O. Ford, L. Frassinetti, S. Freethy, M. Fröschle, G. Fuchert, J.C. Fuchs, H. Fünfgelder, K. Galazka, J. Galdon-Quiroga, A. Gallo, Y. Gao, S. Garavaglia, A. Garcia-Carrasco, M. Garcia-Muñoz, B. Geiger, L. Giannone, L. Gil, E. Giovannozzi, C. Gleason-González, S. Glöggler, M. Gobbin, T. Görler, I. Gomez Ortiz, J. Gonzalez Martin, T. Goodman, G. Gorini, D. Gradic, A. Gräter, G. Granucci, H. Greuner, M. Griener, M. Groth, A. Gude, S. Günter, L. Guimarais, G. Haas, A.H. Hakola, C. Ham, T. Happel, N. den Harder, G.F. Harrer, J. Harrison, V. Hauer, T. Hayward-Schneider, C.C. Hegna, B. Heinemann, S. Heinzel, T. Hellsten, S. Henderson, P. Hennequin, A. Herrmann, M.F. Heyn, E. Heyn, F. Hitzler, J. Hobirk, K. Höfler, M. Hölzl, T. Höschen, J.H. Holm, C. Hopf, W.A. Hornsby, L. Horvath, A. Houben, A. Huber, V. Igochine, T. Ilkei, I. Ivanova-Stanik, W. Jacob, A.S. Jacobsen, F. Janky, A. Jansen van Vuuren, A. Jardin, F. Jaulmes, F. Jenko, T. Jensen, E. Joffrin, C.-P. Käsemann, A. Kallenbach, S. Kálvin, M. Kantor, A. Kappatou, O. Kardaun, J. Karhunen, S. Kasilov,, Y. Kazakov, W. Kernbichler, A. Kirk, S. Kjer Hansen, V. Klevarova, G. Kocsis, A. Köhn, M. Koubiti, K. Krieger, A. Krivska, A. Krämer-Flecken, O. Kudlacek, T. Kurki-Suonio, B. Kurzan, B. Labit, K. Lackner, F. Laggner, P.T. Lang, P. Lauber, A. Lebschy, N. Leuthold, M. Li, O. Linder, B. Lipschultz, F. Liu, Y. Liu, A. Lohs, Z. Lu, T. Luda di Cortemiglia, N.C. Luhmann, R. Lunsford, T. Lunt, A. Lyssoivan, T. Maceina, J. Madsen, R. Maggiora, H. Maier, O. Maj, J. Mailloux, R. Maingi, E. Maljaars, P. Manas, A. Mancini, A. Manhard, M.-E. Manso, P. Mantica, M. Mantsinen, P. Manz, M. Maraschek, C. Martens, P. Martin, L. Marrelli, A. Martitsch, M. Mayer, D. Mazon, P.J. McCarthy, R. McDermott, H. Meister, A. Medvedeva, R. Merkel, A. Merle, V. Mertens, D. Meshcheriakov, O. Meyer, J. Miettunen, D. Milanesio, F. Mink, A. Mlynek, F. Monaco, C. Moon, F. Nabais, A. Nemes-Czopf, G. Neu, R. Neu, A.H. Nielsen, S.K. Nielsen, V. Nikolaeva, M. Nocente, J.-M. Noterdaeme, I. Novikau, S. Nowak, M. Oberkofler, M. Oberparleiter, R. Ochoukov, T. Odstrcil, J. Olsen, F. Orain, F. Palermo, O. Pan, G. Papp, I. Paradela Perez, A. Pau, G. Pautasso, F. Penzel, P. Petersson, J. Pinzón Acosta, P. Piovesan, C. Piron, R. Pitts, U. Plank, B. Plaum, B. Ploeckl, V. Plyusnin, G. Pokol, E. Poli, L. Porte, S. Potzel, D. Prisiazhniuk, T. Pütterich, M. Ramisch, J. Rasmussen, G.A. Rattá, S. Ratynskaia, G. Raupp, G.L. Ravera, D. Réfy, M. Reich, F. Reimold, D. Reiser, T. Ribeiro, J. Riesch, R. Riedl, D. Rittich, J.F. Rivero-Rodriguez, G. Rocchi, M. Rodriguez-Ramos, V. Rohde, A. Ross1, M. Rott, M. Rubel, D. Ryan, F. Ryter, S. Saarelma, M. Salewski, A. Salmi, L. Sanchis-Sanchez, J. Santos, O. Sauter, A. Scarabosio, G. Schall, K. Schmid, O. Schmitz, P.A. Schneider, R. Schrittwieser, M. Schubert, T. Schwarz-Selinger, J. Schweinzer, B. Scott, T. Semer, E. Seliunin, M. Sertoli, A. Shabbir, A. Shalpegin, L. Shao, S. Sharapov, G. Sias, M. Siccinio, B. Sieglin, A. Sigalov, A. Silva, C. Silva, D. Silvagni, P. Simon, J. Simpson, E. Smigelskis, A. Snicker, C. Sommariva, C. Sozzi, M. Spolaore, A. Stegmeir, M. Stejner, J. Stober, U. Stroth, E. Strumberger, G. Suarez, H.-J. Sun, W. Suttrop, E. Sytova, T. Szepesi, B. Tál, T. Tala, G. Tardini, M. Tardocchi, M. Teschke, D. Terranova, W. Tierens, E. Thorén, D. Told, P. Tolias, O. Tudisco, W. Treutterer, E. Trier, M. Tripský, M. Valisa, M. Valovic, B. Vanovac, D. van Vugt, S. Varoutis, G. Verdoolaege, N. Vianello, J. Vicente, T. Vierle, E. Viezzer, U. von Toussaint, D. Wagner, N. Wang, X. Wang, M. Weiland, A.E. White, S. Wiesen, M. Willensdorfer, B. Wiringer, M. Wischmeier, R. Wolf, E. Wolfrum, L. Xiang, Q. Yang, Z. Yang, Q. Yu, R. Zagórski, I. Zammuto, W. Zhang, M. van Zeeland, T. Zehetbauer, M. Zilker, S. Zoletnik, H. Zohm and the EUROfusion MST1 Team55
22 p.
eng
IOP Publishing
Attribution 3.0 Spain
http://creativecommons.org/licenses/by/3.0/es/
Open Access
Àrees temàtiques de la UPC::Física
Nuclear physics
Nuclear fusion
Tokamaks
Nuclear fusion
Magnetic confinement
Tokamak physics
ITER
DEMO
Física nuclear
Overview of physics studies on ASDEX Upgrade
Article
https://iopscience.iop.org/article/10.1088/1741-4326/ab18b8
info:eu-repo/grantAgreement/EC/H2020/633053/EU/Implementation of activities described in the Roadmap to Fusion during Horizon 2020 through a Joint programme of the members of the EUROfusion consortium/EUROfusion
112014
Nuclear Fusion
59
11
eprints
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/909182022-05-17T10:08:36Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Reyes-Garcia, Victoria
Balbo, Andrea L.
Gómez-Baggethun, Erik
Gueze, Maximilien
Mesoudi, Alex
Richerson, Peter J.
Rubio-Campillo, Xavier
Ruiz-Mallén, Isabel
Shennan, Stephen
Barcelona Supercomputing Center
2016-10-20T10:54:39Z
2016-10-20T10:54:39Z
2016
Reyes-Garcia, Victoria [et al.]. Multilevel processes and cultural adaptation: examples from past and present small-scale societies. "Ecology and Society", 2016, vol. 21, núm. 4 : 2.
1708-3087
http://hdl.handle.net/2117/90918
10.5751/ES-08561-210402
The last two decades have seen a proliferation of research frameworks that emphasise the importance of understanding adaptive processes that happen at different levels. We contribute to this growing body of literature by exploring how cultural (mal)adaptive dynamics relate to multilevel social-ecological processes occurring at different scales, where the lower levels combine into new units with new organizations, functions, and emergent properties or collective behaviors. After a brief review of the concept of “cultural adaptation” from the perspective of cultural evolutionary theory, the core of the paper is constructed around the exploration of multilevel processes occurring at the temporal, spatial, social, and political scales. We do so by using insights from cultural evolutionary theory and by examining small-scale societies as case studies. In each section, we discuss the importance of the selected scale for understanding cultural adaptation and then present an example that illustrates how multilevel processes in the selected scale help explain observed patterns in the cultural adaptive process. The last section of the paper discusses the potential of modeling and computer simulation for studying multilevel processes in cultural adaptation. We conclude by highlighting how elements from cultural evolutionary theory might enrich the multilevel process discussion in resilience theory.
This paper resulted from discussions at the ICREA Workshop “Small-Scale Societies and Environmental Transformations: Coevolutionary Dynamics” funded by ICREA Conference Awards.
VRG acknowledges financial support from ERC grant agreement No. FP7-261971-LEK and from the CONSOLIDER SimulPast
Project (CSD2010-00034). ALB worked on this paper on a contract from the Juan de la Cierva Programme (JCI-2011-10734, MICINN-MINECO, Spain) and on a research fellowship from The Alexander von Humboldt Foundation. This work contributes to the ICTA Unit of Excellence (MinECo, MDM2015-0552).
Postprint (author's final draft)
10 p.
eng
Resilience Alliance
Àrees temàtiques de la UPC::Desenvolupament humà i sostenible
Cultural and social perspectives
Cultural Evolution
Computer simulation
Cultural adaptation
Cultural evolution
Multilevel selection
Resilience
Simulació per ordinador
Evolució cultural
Multilevel processes and cultural adaptation: examples from past and present small-scale societies
Article
http://www.ecologyandsociety.org/vol21/iss4/art2/
info:eu-repo/grantAgreement/EC/FP7/261971/EU/The adaptive nature of culture. A cross-cultural analysis of the returns of Local Environmental Knowledge in three indigenous societies/LEK
info:eu-repo/grantAgreement/MINECO//MDM-2015-0552/ES/INSTITUT DE CIENCIA I TECNOLOGIA AMBIENTALS - ICTA/
Open Access
Ecology and Society
21
4 : 2
eprints
10.13039/501100000780
European Commission
10.13039/501100003329
Ministerio de Economía y Competitividad
oai:upcommons.upc.edu:2117/909982020-07-23T23:27:44Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Kormann, Jean
Rodríguez, Juan E.
Ferrer, Miguel
Farrés, Albert
Gutiérrez, Natalia
de la Puente, Josep
Hanzich, Mauricio
Cela, José M.
Barcelona Supercomputing Center
2016-10-24T14:07:01Z
2016-10-24T14:07:01Z
2017-02-01
Kormann, Jean [et al.]. Acceleration strategies for elastic full waveform inversion workflows in 2D and 3D. "Computational Geosciences", 22 Octubre 2016, p. 1-15.
1420-0597
http://hdl.handle.net/2117/90998
10.1007/s10596-016-9593-0
Full waveform inversion (FWI) is one of the most challenging procedures to obtain quantitative information of the subsurface. For elastic inversions, when both compressional and shear velocities have to be inverted, the algorithmic issue becomes also a computational challenge due to the high cost related to modelling elastic rather than acoustic waves. This shortcoming has been moderately mitigated by using high-performance computing to accelerate 3D elastic FWI kernels. Nevertheless, there is room in the FWI workflows for obtaining large speedups at the cost of proper grid pre-processing and data decimation techniques. In the present work, we show how by making full use of frequency-adapted grids, composite shot lists and a novel dynamic offset control strategy, we can reduce by several orders of magnitude the compute time while improving the convergence of the method in the studied cases, regardless of the forward and adjoint compute kernels used.
The authors thank REPSOL for the permission
to publish the present research and for funding through the AURORA project. J. Kormann also thankfully acknowledges the computer
resources, technical expertise and assistance provided by the Barcelona Supercomputing Center - Centro Nacional de Supercomputacti
´on together with the Spanish Supercomputing Network (RES) through grant FI-2014-2-0009. This project has received funding from the European Union’s Horizon 2020, research and innovation programme under the Marie Skłodowska-Curie grant agreement no.
644202. The research leading to these results has received funding from the European Union’s Horizon 2020 Programme (2014–2020)
and from the Brazilian Ministry of Science, Technology and Innovation through Rede Nacional de Pesquisa (RNP) under the HPC4E
Project (www.hpc4e.eu), grant agreement no. 689772.We further want to thank the Editor Clint N. Dawson for his help, and Andreas Fichtner and an anonymous reviewer for their comments and suggestions to improve the manuscript.
Peer Reviewed
Postprint (published version)
15 p.
eng
Springer International Publishing
Àrees temàtiques de la UPC::Enginyeria electrònica
Physical activity
Mathematical modeling and computation
Seismic data
Elastic waves
Inversion
Elastic
Near offset
Ones elàstiques
Sismologia
Acceleration strategies for elastic full waveform inversion workflows in 2D and 3D
Article
http://link.springer.com/article/10.1007/s10596-016-9593-0
info:eu-repo/grantAgreement/EC/H2020/644202/EU/Geophysical Exploration using Advanced GAlerkin Methods/GEAGAM
info:eu-repo/grantAgreement/EC/H2020/689772/EU/HPC for Energy/HPC4E
Open Access
Computational Geosciences
21
21
1
1
31
31
45
45
eprints
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/847602020-07-23T23:27:44Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Puzyrev, Vladimir
Koric, Seid
Wilkin, Scott
Barcelona Supercomputing Center
2016-03-21T14:30:10Z
2018-04-03T00:30:22Z
2016-04
Puzyrev, Vladimir; Koric, Seid; Wilkin, Scott. Evaluation of parallel direct sparse linear solvers in electromagnetic geophysical problems. "Computers & Geosciences", Abril 2016, vol. 89, p. 79-87.
0098-3004
http://hdl.handle.net/2117/84760
10.1016/j.cageo.2016.01.009
High performance computing is absolutely necessary for large-scale geophysical simulations. In order to obtain a realistic image of a geologically complex area, industrial surveys collect vast amounts of data making the computational cost extremely high for the subsequent simulations. A major computational bottleneck of modeling and inversion algorithms is solving the large sparse systems of linear ill-conditioned equations in complex domains with multiple right hand sides. Recently, parallel direct solvers have been successfully applied to multi-source seismic and electromagnetic problems. These methods are robust and exhibit good performance, but often require large amounts of memory and have limited scalability. In this paper, we evaluate modern direct solvers on large-scale modeling examples that previously were considered unachievable with these methods. Performance and scalability tests utilizing up to 65,536 cores on the Blue Waters supercomputer clearly illustrate the robustness, efficiency and competitiveness of direct solvers compared to iterative techniques. Wide use of direct methods utilizing modern parallel architectures will allow modeling tools to accurately support multi-source surveys and 3D data acquisition geometries, thus promoting a more efficient use of the electromagnetic methods in geophysics.
The authors would like to thank the MUMPS and PARDISO developers for providing free academic licenses and Dr. Anshul Gupta for access to his solver library which is not publicly available. We also would like to thank the Private Sector Program and the Blue Waters sustained-petascale computing project at the
National Center for Supercomputing Applications (NCSA), which is supported by the National Science Foundation (awards OCI-
0725070 and ACI-1238993) and the state of Illinois. The shared-memory tests were performed on the MareNostrum supercomputer of the Barcelona Supercomputer Center. The first author
acknowledges funding from the Repsol-BSC Research Center through the AURORA project and support from the RISE Horizon 2020 European Project GEAGAM (644602). The authors wish to thank Jef Caers and two anonymous reviewers for their valuable
comments that significantly helped to improve this paper.
Peer Reviewed
Postprint (author's final draft)
9 p.
eng
Elsevier
Attribution-NonCommercial-NoDerivs 4.0 International License
https://creativecommons.org/licenses/by-nc-nd/4.0/
Open Access
Àrees temàtiques de la UPC::Enginyeria mecànica::Impacte ambiental
Large scale systems--Data processing
Numerical modeling
Linear systems
Direct solvers
Parallel computing
Controlled-source electromagnetics
Geophysical exploration
Electromagnetisme--Mesuraments
Evaluation of parallel direct sparse linear solvers in electromagnetic geophysical problems
Article
http://www.sciencedirect.com/science/article/pii/S0098300416300164
info:eu-repo/grantAgreement/EC/H2020/644606/EU/EU-wide outreach for promoting photonics to young people, entrepreneurs and the general public/Photonics4All
info:eu-repo/grantAgreement/EC/H2020/644202/EU/Geophysical Exploration using Advanced GAlerkin Methods/GEAGAM
Computers & Geosciences
89
79
87
eprints
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3297282020-10-11T02:38:38Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Siena, Alessandro di
Görler, Tobias
Bañon Navarro, Alejandro
Biancalani, Alessandro
Bilato, Roberto
Mantsinen, Mervi J.
Oliveira Lopes, Felipe Nathan de
Jenko, Frank
Barcelona Supercomputing Center
EUROfusion MST1 team
ASDEX Upgrade team
2020-10-02T13:13:36Z
2020-10-02T13:13:36Z
2019-09
Siena, A. di [et al.]. Electromagnetic turbulence suppression by energetic particle driven modes. "Nuclear Fusion", Setembre 2019, vol. 59, núm. 12, 124001.
0029-5515
http://hdl.handle.net/2117/329728
10.1088/1741-4326/ab4088
In recent years, a strong reduction of plasma turbulence in the presence of energetic particles has been reported in a number of magnetic confinement experiments and corresponding gyrokinetic simulations. While highly relevant to performance predictions for burning plasmas, an explanation for this primarily nonlinear effect has so far remained elusive. A thorough analysis finds that linearly marginally stable energetic particle driven modes are excited nonlinearly, depleting the energy content of the turbulence and acting as an additional catalyst for energy transfer to zonal modes (the dominant turbulence saturation channel). Respective signatures are found in a number of simulations for different JET and ASDEX Upgrade discharges with reduced transport levels attributed to energetic ion effects.
The simulations presented in this work were performed at the Cobra HPC system at the Max Planck Computing and Data Facility (MPCDF), Germany. This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014-2018 and 2019-2020 under grant agreement No. 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. Furthermore, we acknowledge the CINECA award under the ISCRA initiative, for the availability of high performance computing resources and support. The authors would like to thank N. Bonanomi, J. Citrin, H. Doerk, Ph. Lauber, P. Manas, P. Mantica, M.J. Pueschel, K. Stimmel, P.W. Terry, D. Zarzoso, and A. Zocco for all the stimulating discussions, useful suggestions and comments.
Peer Reviewed
Postprint (published version)
9 p.
eng
IOP Publishing
https://iopscience.iop.org/article/10.1088/1741-4326/ab95d3
https://iopscience.iop.org/article/10.1088/1741-4326/ab4088
info:eu-repo/grantAgreement/EC/H2020/633053/EU/Implementation of activities described in the Roadmap to Fusion during Horizon 2020 through a Joint programme of the members of the EUROfusion consortium/EUROfusion
Àrees temàtiques de la UPC::Física
Electromagnetic waves
Plasma turbulence
Energetic particles
Plasma turbulence
Nonlinear mode coupling
Marginally stable modes
Plasma
Electromagnetic turbulence suppression by energetic particle driven modes
Article
Open Access
124001
Nuclear Fusion
59
12
eprints
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/1926542023-07-16T01:01:06Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577com_2117_184556com_2117_184544com_2117_15797col_2117_80523col_2117_184725col_2117_3055openAccess
Mira Martínez, Daniel
Lehmkuhl Barba, Oriol
Both, Ambrus
Stathopoulos, Panagiotis
Tanneberger, Tom
Reichel, Thoralf G.
Paschereit, Christian Oliver
Vázquez, Mariano
Houzeaux, Guillaume
Universitat Politècnica de Catalunya. Doctorat en Ciència i Tecnologia Aeroespacials
Barcelona Supercomputing Center
2020-07-08T14:01:06Z
2021-01-06T01:29:01Z
2020-03
Mira, D. [et al.]. Numerical characterization of a technically premixed hydrogen flame under conditions close to flashback. "Flow turbulence and combustion", Març 2020, vol. 104, p. 479-507.
1386-6184
http://hdl.handle.net/2117/192654
10.1007/s10494-019-00106-z
This work presents a numerical study of a technically premixed swirling combustor with central air injection at conditions close to flashback using large-eddy simulation with flamelet modelling. This burner has the characteristics of showing flashback at low equivalence ratios, so numerical simulations are set to identify the mechanisms behind the flashback formation. Experimental findings suggest the axial momentum ratio between fuel and air dominates the flame stabilization mechanism and flashback resistance over mixing and equivalence ratio fluctuations. This aspect is investigated here for two operating conditions with the same axial momentum ratio as in the experiment using a perfectly premixed assumption. The two test cases correspond to two stable operating points, far and close to the flashback point. The study shows the assumption of perfect premixing is valid during the stable operation of the burner up to flashback conditions. The experimental results are well predicted under inert and reacting conditions by using a perfectly premixed mixture. It is found that the non reacting flow field develops a self-excited oscillation in the form of a precessing vortex core. This oscillation is attenuated by the fuel injection due to the respective increase in axial momentum and it is ultimately suppressed in the reacting flow field. Both experiments and simulations confirm the same trends. The analysis of the flames have shown certain dynamics as the flashback point is approached. The flashback resistance of the burner is minimized due to an increase in the velocity deficit of the incoming mixture. The recirculation region is shifted upstream, the central recirculation is altered and the flame position is displaced towards the inlet of the reactants in the combustion chamber. The analysis of instabilities and flow dynamics suggest that the formation of flashback can be attributed to combustion induced vortex breakdown, which in turn is associated to the lower axial momentum introduced by the fuel jets in leaner conditions.
The research leading to these results has received funding through the Spanish Ministry of Economy and Competitiveness in the frame of the CHEST project (TRA2017- 89139-C2-2-R). Conflict of Interest: Daniel Mira acknowledges the Juan de la Cierva personal grant IJCI-2015-26686 and Ambrus Both the Marie Skłodowska-Curie grant agreement No. 713673 through the ”la Caixa” INPhINIT Fellowship Grant. Computer resources and technical assistance has been provided by the Red Española de Supercomputación (RES) and the Gauss Centre for Supercomputing e.V. (www.gauss-centre.eu) on the GCS Supercomputer SuperMUC at Leibniz Supercomputing Centre (www.lrz.de). The TU Berlin would like to acknowledge the funding received from the EU Seventh Framework Program (FP7/2007-2013) under GA284636 and the European Research Council under the ERC GREENEST with GA247322.
Peer Reviewed
Postprint (author's final draft)
29 p.
eng
Springer
Àrees temàtiques de la UPC::Aeronàutica i espai::Astronàutica::Enginyeria aeroespacial
Combustion
Premixed burner
Swirl-stabilized flames
Flashback safety
Precessing vortex core
Flamelet
Combustió
Numerical characterization of a technically premixed hydrogen flame under conditions close to flashback
Article
https://link.springer.com/article/10.1007/s10494-019-00106-z
info:eu-repo/grantAgreement/EC/H2020/713673/EU/Innovative doctoral programme for talented early-stage researchers in Spanish host organisations excellent in the areas of Science, Technology, Engineering and Mathematics (STEM)./INPhINIT
info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016/TRA2017-89139-C2-2-R/ES/IMPLEMENTACION Y VALIDACION DE MODELOS HPC DE COMBUSTION Y EMISIONES PARA EL ANALISIS DE SISTEMAS DE TRANSPORTE SOSTENIBLES/
info:eu-repo/grantAgreement/MINECO//IJCI-2015-26686/ES/IJCI-2015-26686/
Open Access
28844675
Mira, D.; Lehmkuhl, O.; Both, A.; Stathopoulos, P.; Tanneberger , T.; Reichel , T. G.; Paschereit, C.O.; Vázquez, M.; Houzeaux, G.
Flow turbulence and combustion
104
479
507
eprints
10.13039/501100000780
European Commission
10.13039/501100011033
Agencia Estatal de Investigación
10.13039/501100003329
Ministerio de Economía y Competitividad
oai:upcommons.upc.edu:2117/3449152021-05-04T04:08:20Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Zamora, Natalia
Catalán, Patricio A.
Gubler, Alejandra
Carvajal, Matías
Barcelona Supercomputing Center
2021-04-30T14:35:56Z
2021-04-30T14:35:56Z
2021
Zamora, N. [et al.]. Microzoning tsunami hazard by combining flow depths and arrival times. "Frontiers in Earth Science", 2021, vol. 8, p. 747.
2296-6463
http://hdl.handle.net/2117/344915
10.3389/feart.2020.591514
Tsunami hazard is typically assessed from inundation flow depths estimated from one or many earthquake scenarios. However, information about the exact time when such inundation occurs is seldom considered, yet it is crucial for pedestrian evacuation planning. Here, we propose an approach to estimating tsunami hazard by combining tsunami flow depths and arrival times to produce a nine-level, qualitative hazard scale that is translated into a simple tsunami hazard map. To do this, one of the most populated regions of the coast of Chile is considered as the sample site, using a large set of 2,800 tsunamigenic sources from earthquakes with magnitudes in the range <mml:math id="minf1" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>M</mml:mi><mml:mi>w</mml:mi></mml:msub><mml:mn>8.6</mml:mn><mml:mo>−</mml:mo><mml:mn>9.2</mml:mn></mml:mrow></mml:math>, modeled from generation to inundation at high resolution. Main outcomes show great dependency of the hazard categorization on the tsunami time arrival, and less to the flow depths. Also, these results demonstrate that incorporating different sources of variability such as different earthquake magnitudes and locations as well as stochastic slip distributions is essential. Moreover, this proof-of-concept exercise clearly shows that the qualitative hybrid categorization of the tsunami hazard allows for its more effective understanding, which can be beneficial for designing mitigation strategies such as evacuation planning, and its management.
The authors acknowledge SHOA’s support to this work, particularly making available nautical charts and coastal zone plans used to generate high resolution terrain models. PC, NZ and AG were partially funded by ANID through its grants ANID/FONDAP/15110017 (CIGIDEN), and ANID/FONDEF/ID19I10048. PAC also thanks ANID PIA/APOYO AFB180002. MC acknowledges the support from ‘Millennium Nucleus CYCLO: The Seismic Cycle Along Subduction Zones’ and Chile’s Fondo Nacional de Desarrollo Científico y Tecnológico, FONDECYT Projects N°1190258 and N° 1181479. The authors also acknowledge C. Sippl for discussion about asperities offshore Valparaíso and corrections to the manuscript. The authors thankfully acknowledges the computer resources at CTE-POWER and the technical support provided by BSC (RES-AECT-2020-2-0001), and the EDANYA Group at Málaga university for providing the HySEA code. We acknowledge D. Melgar for making available the MudPy code at: https://github.com/dmelgarm/MudPy. J. León is acknowledge for sharing the evacuation results. We are very grateful to the editor S. Lorito and the comments of K. Goda, A. Armigliato and W. Power, for a thoughtful and insightful discussion that helped us to greatly improve this work. NZ has received funding from the STARS programme part of the Marie Skłodowska-Curie grant agreement H2020-MSCA-COFUND-2016-754433.
Peer Reviewed
Postprint (published version)
18 p.
eng
Frontiers Media
https://www.frontiersin.org/articles/10.3389/feart.2020.591514/full#supplementary-material.
https://www.frontiersin.org/article/10.3389/feart.2020.591514
info:eu-repo/grantAgreement/EC/H2020/754433/EU/SupercompuTing And Related applicationS Fellows Program/STARS
Attribution 3.0 Spain
http://creativecommons.org/licenses/by/3.0/es/
Open Access
Àrees temàtiques de la UPC::Enginyeria agroalimentària::Ciències de la terra i de la vida
Tsunami hazard zones
Computer simulation
Chile
Tsunami Hazard
Microzoning
Arrival times
Flow depths
Evacuation
Slip distributions
Earthquakes
Central Chile
Terratrèmols
Tsunamis
Microzoning tsunami hazard by combining flow depths and arrival times
Article
Frontiers in Earth Science
8
747
eprints
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3662672022-04-24T13:55:09Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Webber, Matthew
Falconer, Debbie
AlFarih, Mashael
Joy, George
Chan, Fiona
Aguado Sierra, Jazmín
Vázquez, Mariano
Barcelona Supercomputing Center
2022-04-22T14:36:26Z
2022-04-22T14:36:26Z
2022-04
Webber, M. [et al.]. Study protocol: MyoFit46—the cardiac sub-study of the MRC National Survey of Health and Development. "BMC Cardiovascular Disorders", Abril 2022, vol. 22, núm. 1.
1471-2261
http://hdl.handle.net/2117/366267
10.1186/s12872-022-02582-0
Background
The life course accumulation of overt and subclinical myocardial dysfunction contributes to older age mortality, frailty, disability and loss of independence. The Medical Research Council National Survey of Health and Development (NSHD) is the world’s longest running continued surveillance birth cohort providing a unique opportunity to understand life course determinants of myocardial dysfunction as part of MyoFit46–the cardiac sub-study of the NSHD.
Methods
We aim to recruit 550 NSHD participants of approximately 75 years+ to undertake high-density surface electrocardiographic imaging (ECGI) and stress perfusion cardiovascular magnetic resonance (CMR). Through comprehensive myocardial tissue characterization and 4-dimensional flow we hope to better understand the burden of clinical and subclinical cardiovascular disease. Supercomputers will be used to combine the multi-scale ECGI and CMR datasets per participant. Rarely available, prospectively collected whole-of-life data on exposures, traditional risk factors and multimorbidity will be studied to identify risk trajectories, critical change periods, mediators and cumulative impacts on the myocardium.
Discussion
By combining well curated, prospectively acquired longitudinal data of the NSHD with novel CMR–ECGI data and sharing these results and associated pipelines with the CMR community, MyoFit46 seeks to transform our understanding of how early, mid and later-life risk factor trajectories interact to determine the state of cardiovascular health in older age.
Trial registration: Prospectively registered on ClinicalTrials.gov with trial ID: 19/LO/1774 Multimorbidity Life-Course Approach to Myocardial Health- A Cardiac Sub-Study of the MCRC National Survey of Health and Development (NSHD).
Sources of funding used for staff salaries, CMR scan costs, consumables and relevant travel costs required for data collection, analysis and interpretation: British Heart Foundation special project grant (to G.C. SP/20/2/34841). This study has undergone peer-review by the funding body. Medical Research Council (Core Unit Level Funding:—MC UU 00019/1).
Peer Reviewed
Postprint (published version)
"Article signat per 30 autors/es: Matthew Webber, Debbie Falconer, Mashael AlFarih, George Joy, Fiona Chan, Clare Davie, Lee Hamill Howes, Andrew Wong, Alicja Rapala, Anish Bhuva, Rhodri H. Davies, Christopher Morton, Jazmin Aguado-Sierra, Mariano Vazquez, Xuyuan Tao, Gunther Krausz, Slobodan Tanackovic, Christoph Guger, Hui Xue, Peter Kellman, Iain Pierce, Jonathan Schott, Rebecca Hardy, Nishi Chaturvedi, Yoram Rudy, James C. Moon, Pier D. Lambiase, Michele Orini, Alun D. Hughes & Gabriella Captur"
eng
BioMed Central (BMC)
Attribution 3.0 Spain
Attribution 4.0 International (CC BY 4.0)
http://creativecommons.org/licenses/by/3.0/es/
https://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Informàtica::Aplicacions de la informàtica::Aplicacions informàtiques a la física i l‘enginyeria
Myocardial infarction--Age factors
Electrocardiographs
Magnetic resonance imaging
Supercomputer
Subclinical myocardial dysfunction
Cardiovascular health
Life course risk factors
Risk trajectories
Cardiovascular magnetic resonance
Electrocardiographic imaging
Myocardial tissue characterization
Perfusion
4-dimensional flow
Sistema cardiovascular--Malalties
Simulació per ordinador
Study protocol: MyoFit46—the cardiac sub-study of the MRC National Survey of Health and Development
Article
https://bmccardiovascdisord.biomedcentral.com/articles/10.1186/s12872-022-02582-0
BMC Cardiovascular Disorders
22
1
eprints
oai:upcommons.upc.edu:2117/1032272020-10-11T03:04:35Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Marti, Alejandro
Folch, Arnau
Jorba, Oriol
Janjic, Zavisa
Barcelona Supercomputing Center
2017-04-03T13:54:45Z
2017-04-03T13:54:45Z
2017-03-24
Marti, A. [et al.]. Volcanic ash modeling with the online NMMB-MONARCH-ASH v1.0 model: model description, case simulation, and evaluation. "Atmospheric Chemistry and Physics", 24 Març 2017, vol. 17, p. 4005-4030.
1680-7316
http://hdl.handle.net/2117/103227
10.5194/acp-17-4005-2017
Traditionally, tephra transport and dispersal models have evolved decoupled (offline) from numerical weather prediction models. There is a concern that inconsistencies and shortcomings associated with this coupling strategy might lead to errors in the ash cloud forecast. Despite this concern and the significant progress in improving the accuracy of tephra dispersal models in the aftermath of the 2010 Eyjafjallajökull and 2011 Cordón Caulle eruptions, to date, no operational online dispersal model is available to forecast volcanic ash. Here, we describe and evaluate NMMB-MONARCH-ASH, a new online multi-scale meteorological and transport model that attempts to pioneer the forecast of volcanic aerosols at operational level. The model forecasts volcanic ash cloud trajectories, concentration of ash at relevant flight levels, and the expected deposit thickness for both regional and global configurations. Its online coupling approach improves the current state-of-the-art tephra dispersal models, especially in situations where meteorological conditions are changing rapidly in time, two-way feedbacks are significant, or distal ash cloud dispersal simulations are required. This work presents the model application for the first phases of the 2011 Cordón Caulle and 2001 Mount Etna eruptions. The computational efficiency of NMMB-MONARCH-ASH and its application results compare favorably with other long-range tephra dispersal models, supporting its operational implementation.
The research leading to these results has received funding from the People Programme (Marie Curie Actions) of the European Union’s Seventh Framework Programme (FP7/2007-2013) under the project NEMOH (REA grant agreement
no. 289976). O. Jorba was partially funded by grant CGL2013-46736 of the Ministry of Economy and Competitiveness of Spain.
We are extremely grateful to the Argentinian National Meteorological Service for sharing data to validate this work; in particular we
thank M.S. Osores for providing valuable insights into the eruption dynamics. Numerical simulations were performed at the Barcelona
Supercomputing Center with the MareNostrum Supercomputer using 512 and 256 - 8x4 GB DDR3-1600 DIMMS (2GB/core) Intel Sandy Bridge processors, iDataPlex Compute Racks, a Linux Operating System, and an InfiniBand interconnection.
Postprint (published version)
26 p.
eng
European Geosciences Union (EGU)
Attribution 3.0 Spain
http://creativecommons.org/licenses/by/3.0/es/
Open Access
Àrees temàtiques de la UPC::Energies
Volcanic activity prediction
Forecasting--Computer simulation
Simulation methods
Volcanic ash modeling
Meteorological model
Activitat volcànica--Previsió
Simulació per ordinador digital
Volcanic ash modeling with the online NMMB-MONARCH-ASH v1.0 model: model description, case simulation, and evaluation
Article
http://www.atmos-chem-phys.net/17/4005/2017/
info:eu-repo/grantAgreement/MINECO/1PE/CGL2013-46736
Atmospheric Chemistry and Physics
17
4005
4030
eprints
oai:upcommons.upc.edu:2117/847642020-07-23T23:27:45Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Casoni Rero, Eva
Jérusalem, Antoine
Samaniego, Cristóbal
Eguzkitza, Beatriz
Lafortune, Pierre
Tjahjanto, Denny
Sáez, Xavier
Houzeaux, Guillaume
Vázquez, Mariano
Barcelona Supercomputing Center
2016-03-22T09:52:29Z
2016-03-22T09:52:29Z
2014-08-13
Casoni, Eva [et al.]. Alya: Computational Solid Mechanics for Supercomputers. "Archives of Computational Methods in Engineering", 13 Agost 2014, vol. 22, núm. 4, p. 557-576.
1134-3060
http://hdl.handle.net/2117/84764
10.1007/s11831-014-9126-8
While solid mechanics codes are now conventional tools both in industry and research, the increasingly more exigent requirements of both sectors are fuelling the need for more computational power and more advanced algorithms. For obvious reasons, commercial codes are lagging behind academic codes often dedicated either to the implementation of one new technique, or the upscaling of current conventional codes to tackle massively large scale computational problems. Only in a few cases, both approaches have been followed simultaneously. In this article, a solid mechanics simulation strategy for parallel supercomputers based on a hybrid approach is presented. Hybrid parallelization exploits the thread-level parallelism of multicore architectures, combining MPI tasks with OpenMP threads. This paper describes the proposed strategy, programmed in Alya, a parallel multi-physics code. Hybrid parallelization is specially well suited for the current trend of supercomputers, namely large clusters of multicores. The strategy is assessed through transient non-linear solid mechanics problems, both for explicit and implicit schemes, running on thousands of cores. In order to demonstrate the flexibility of the proposed strategy under advance algorithmic evolution of computational mechanics, a non-local parallel overset meshes method (Chimera-like) is implemented and the conservation of the scalability is demonstrated.
D.D.T and A.J acknowledge funding through
SIMUCOMP and ERA-NET MATERA+ project financed by the Consejería de Educación y Empleo of the Comunidad de Madrid and
by the European Union’s Seventh Framework Programme (FP7/2007-2013). Thisworkwas partially supported by the grant SEV-2011-00067, Severo Ochoa Program, awarded by the Spanish Government. The
authors’ would like to acknowledge PRACE infrastructure support.
Peer Reviewed
Postprint (published version)
20 p.
eng
Springer
Àrees temàtiques de la UPC::Enginyeria mecànica
Computer systems
Supercomputers
Computational mechanics
Finite element method
Parallel computing
Chimera
Supercomputadors
Alya: Computational Solid Mechanics for Supercomputers
Article
http://link.springer.com/article/10.1007%2Fs11831-014-9126-8#/page-1
info:eu-repo/grantAgreement/EC/FP7/285380/EU/The Productive Robot Apprentice/PRACE
info:eu-repo/grantAgreement/MINECO/SEV-2011-00067
info:eu-repo/grantAgreement/EC/FP7/235303/EU/ERA-NET Plus on Materials Research/MATERA+
Open Access
Archives of Computational Methods in Engineering
22
4
557
576
eprints
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3631092022-02-27T15:33:35Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Vinuesa, Ricardo
Lehmkuhl Barba, Oriol
Lozano Durán, Adrian
Rabault, Jean
Barcelona Supercomputing Center
2022-02-25T14:23:46Z
2022-02-25T14:23:46Z
2022
Vinuesa, R. [et al.]. Flow Control in Wings and Discovery of Novel Approaches via Deep Reinforcement Learning. "Fluids", 2022, vol. 7, núm. 2, 62.
2311-5521
http://hdl.handle.net/2117/363109
10.3390/fluids7020062
In this review, we summarize existing trends of flow control used to improve the aerodynamic efficiency of wings. We first discuss active methods to control turbulence, starting with flat-plate geometries and building towards the more complicated flow around wings. Then, we discuss active approaches to control separation, a crucial aspect towards achieving a high aerodynamic efficiency. Furthermore, we highlight methods relying on turbulence simulation, and discuss various levels of modeling. Finally, we thoroughly revise data-driven methods and their application to flow control, and focus on deep reinforcement learning (DRL). We conclude that this methodology has the potential to discover novel control strategies in complex turbulent flows of aerodynamic relevance.
R.V. acknowledges the financial support from the Swedish Research Council (VR). O.L. is partially financed by a Ramón y Cajal postdoctoral contract by the Ministerio de Economía y Competitividad, Secretaría de Estado de Investigación, Desarrollo e Innovación, Spain (RYC2018-025949-I).
Peer Reviewed
Postprint (published version)
15 p.
eng
MDPI
Attribution 3.0 Spain
Attribution 4.0 International (CC BY 4.0)
http://creativecommons.org/licenses/by/3.0/es/
https://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Informàtica::Aplicacions de la informàtica::Aplicacions informàtiques a la física i l‘enginyeria
Aerodynamics--Mathematical models
Turbulence
Aviation
Turbulence
Flow control
Simulation
Aerodynamics
Machine learning
Deep reinforcement learning
Aerodinàmica
Flow Control in Wings and Discovery of Novel Approaches via Deep Reinforcement Learning
Article
https://www.mdpi.com/2311-5521/7/2/62
62
Fluids
7
2
eprints
oai:upcommons.upc.edu:2117/847612021-06-20T02:36:28Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Calmet, Hadrien
Gambaruto, Alberto M.
Bates, Alister J.
Vázquez, Mariano
Houzeaux, Guillaume
Doorly, Denis J.
Barcelona Supercomputing Center
2016-03-21T15:06:00Z
2017-02-01T01:30:31Z
2016-02-01
Calmet, Hadrien [et al.]. Large-scale CFD simulations of the transitional and turbulent regime for the large human airways during rapid inhalation. "Computers in Biology and Medicine", 01 Febrer 2016, vol. 69, p. 166-180.
0010-4825
http://hdl.handle.net/2117/84761
10.1016/j.compbiomed.2015.12.003
The dynamics of unsteady flow in the human large airways during a rapid inhalation were investigated using highly detailed large-scale computational fluid dynamics on a subject-specific geometry. The simulations were performed to resolve all the spatial and temporal scales of the flow, thanks to the use of massive computational resources. A highly parallel finite element code was used, running on two supercomputers, solving the transient incompressible Navier–Stokes equations on unstructured meshes. Given that the finest mesh contained 350 million elements, the study sets a precedent for large-scale simulations of the respiratory system, proposing an analysis strategy for mean flow, fluctuations and wall shear stresses on a rapid and short inhalation (a so-called sniff). The geometry used encompasses the exterior face and the airways from the nasal cavity, through the trachea and up to the third lung bifurcation; it was derived from a contrast-enhanced computed tomography (CT) scan of a 48-year-old male. The transient inflow produces complex flows over a wide range of Reynolds numbers (Re). Thanks to the high fidelity simulations, many features involving the flow transition were observed, with the level of turbulence clearly higher in the throat than in the nose. Spectral analysis revealed turbulent characteristics persisting downstream of the glottis, and were captured even with a medium mesh resolution. However a fine mesh resolution was found necessary in the nasal cavity to observe transitional features. This work indicates the potential of large-scale simulations to further understanding of airway physiological mechanics, which is essential to guide clinical diagnosis; better understanding of the flow also has implications for the design of interventions such as aerosol drug delivery.
We acknowledge PRACE for awarding us access to resource FERMI based in Italy at Bologna hosted by Cineca. This work was
financially supported by the PRACE project Pra04 693 (2011050693 to the Fourth PRACE regular call). The second author
gratefully acknowledges support from project
‘MatComPhys’ under the European Research Executive Agency FP7-PEOPLE-2011-
IEF framework. The third author was supported by the Engineering and Physical Sciences Research Council [grant number EP/
M506345/1].
Peer Reviewed
Postprint (author's final draft)
15 p.
eng
Elsevier
Attribution-NonCommercial-NoDerivs 4.0 International License
https://creativecommons.org/licenses/by-nc-nd/4.0/
Open Access
Àrees temàtiques de la UPC::Enginyeria electrònica::Impacte ambiental
Turbulent flow
Large scale systems--Data processing
CFD
Airways
Turbulence
Inspiratory flow
Respiratory airflow
Simulació, Mètodes de
Fluxos (Sistemes dinàmics diferenciables)
Large-scale CFD simulations of the transitional and turbulent regime for the large human airways during rapid inhalation
Article
http://www.sciencedirect.com/science/article/pii/S0010482515003881
info:eu-repo/grantAgreement/EC/FP7/302320/EU/Mathematical Models and High Performance Computing for Deposition and Absorption in Physiological Flows/MATCOMPHYS
info:eu-repo/grantAgreement/EC/H2020/653838/EU/PRACE 4th Implementation Phase Project/PRACE-4IP
Computers in Biology and Medicine
69
166
180
eprints
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3666132023-10-09T07:58:28Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Freitas, Rodolfo S.M
Rochinha, Fernando A.
Mira Martínez, Daniel
Jiang, Xi
Barcelona Supercomputing Center
2022-04-29T13:57:31Z
2022-07-20T00:26:08Z
2020
Freitas, R.S.. [et al.]. Parametric and model uncertainties induced by reduced order chemical mechanisms for biogas combustion. "Chemical Engineering Science", 2020, vol. 227, 115949.
0009-2509
http://hdl.handle.net/2117/366613
10.1016/j.ces.2020.115949
This study investigates the impact of chemical kinetic uncertainties on biogas combustion using a Uncertainty Quantification (UQ)-based methodology. The results indicate that the variation of physicochemical properties introduced by composition variability introduces smaller uncertainties in the resulting flame properties than the Arrhenius parameters involved in the kinetics used to describe the oxidation process. We demonstrate that the use of reduced mechanisms for methane-air oxidation could be a starting point to develop optimized schemes for biogas combustion. In that regard, we adopted an embedded discrepancy approach to understanding the limits of the use of a reduced mechanism for methane/air in this renewable fuel. This strategy provides a way to reduce systematically the cost of reaction kinetics in simulations, while quantifying the accuracy of predictions of important target quantities. Finally, we develop a surrogate model for biogas flame propagation using machine learning techniques to make feasible a broader UQ analysis.
The research leading to these results had received funding from the European Union’s Horizon2020 Programme (2014-2020) and from Brazilian Ministry of Science, Technology and Innovation through Rede Nacional de Pesquisa (RNP) under the HPC4E Project (www.hpc4e.eu), grant
agreement number 689772
Peer Reviewed
Postprint (author's final draft)
eng
Elsevier
Attribution-NonCommercial-NoDerivs 3.0 Spain
http://creativecommons.org/licenses/by-nc-nd/3.0/es/
Open Access
Àrees temàtiques de la UPC::Informàtica::Aplicacions de la informàtica::Aplicacions informàtiques a la física i l‘enginyeria
Machine learning
Biogas combustion
Machine learning
Model error
Surrogate modeling
Uncertainty quantification
Combustibles gasosos
Simulació per ordinador
Parametric and model uncertainties induced by reduced order chemical mechanisms for biogas combustion
Article
https://www.sciencedirect.com/science/article/pii/S0009250920304814
115949
Chemical Engineering Science
227
eprints
oai:upcommons.upc.edu:2117/3807422023-02-10T08:25:26Zcom_2117_79677com_2117_28579com_2117_28577com_2117_98851com_2117_28581com_2117_80515com_2117_23714com_2117_28578com_2117_15797col_2117_79695col_2117_103655col_2117_80523col_2117_3055openAccess
Varela Martínez, Pau
Suárez Morales, Pol
Alcántara Ávila, Francisco
Miró Jané, Arnau
Rabault, Jean
Font García, Bernat
García Cuevas, Luis Miguel
Lehmkuhl Barba, Oriol
Vinuesa Moltiva, Ricardo
Universitat Politècnica de Catalunya. Departament de Física
Barcelona Supercomputing Center
Universitat Politècnica de Catalunya. TUAREG - Turbulence and Aerodynamics in Mechanical and Aerospace Engineering Research Group
2023-01-19T09:01:31Z
2023-01-19T09:01:31Z
2022-12-02
Varela, P. [et al.]. Deep reinforcement learning for flow control exploits different physics for increasing Reynolds number regimes. "Actuators", 2 Desembre 2022, vol. 11, núm. 12, article 359, p. 1-24.
2076-0825
http://hdl.handle.net/2117/380742
10.3390/act11120359
The increase in emissions associated with aviation requires deeper research into novel sensing and flow-control strategies to obtain improved aerodynamic performances. In this context, data-driven methods are suitable for exploring new approaches to control the flow and develop more efficient strategies. Deep artificial neural networks (ANNs) used together with reinforcement learning, i.e., deep reinforcement learning (DRL), are receiving more attention due to their capabilities of controlling complex problems in multiple areas. In particular, these techniques have been recently used to solve problems related to flow control. In this work, an ANN trained through a DRL agent, coupled with the numerical solver Alya, is used to perform active flow control. The Tensorforce library was used to apply DRL to the simulated flow. Two-dimensional simulations of the flow around a cylinder were conducted and an active control based on two jets located on the walls of the cylinder was considered. By gathering information from the flow surrounding the cylinder, the ANN agent is able to learn through proximal policy optimization (PPO) effective control strategies for the jets, leading to a significant drag reduction. Furthermore, the agent needs to account for the coupled effects of the friction- and pressure-drag components, as well as the interaction between the two boundary layers on both sides of the cylinder and the wake. In the present work, a Reynolds number range beyond those previously considered was studied and compared with results obtained using classical flow-control methods. Significantly different forms of nature in the control strategies were identified by the DRL as the Reynolds number Re increased. On the one hand, for Re=1000 , the classical control strategy based on an opposition control relative to the wake oscillation was obtained. On the other hand, for Re=2000 , the new strategy consisted of energization of the boundary layers and the separation area, which modulated the flow separation and reduced the drag in a fashion similar to that of the drag crisis, through a high-frequency actuation. A cross-application of agents was performed for a flow at Re=2000 , obtaining similar results in terms of the drag reduction with the agents trained at Re=1000 and 2000. The fact that two different strategies yielded the same performance made us question whether this Reynolds number regime (Re=2000 ) belongs to a transition towards a nature-different flow, which would only admits a high-frequency actuation strategy to obtain the drag reduction. At the same time, this finding allows for the application of ANNs trained at lower Reynolds numbers, but are comparable in nature, saving computational resources.
Pau Varela is partially supported through a grant for the mobility of doctoral students provided by Universitat Politècnica de València and the program Erasmus Prácticas E+ 2020-1. R.V. acknowledges funding from the ERC through grant no. “2021-CoG-101043998, DEEPCONTROL”.
Peer Reviewed
Postprint (published version)
24 p.
eng
Multidisciplinary Digital Publishing Institute (MDPI)
Attribution 4.0 International
http://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Informàtica::Intel·ligència artificial::Aprenentatge automàtic
Àrees temàtiques de la UPC::Física::Física de fluids
Computational fluid dynamics
Machine learning
Deep learning
Numerical simulation
Wake dynamics
Flow control
Deep reinforcement learning
Dinàmica de fluids computacional
Aprenentatge automàtic
Aprenentatge profund
Deep reinforcement learning for flow control exploits different physics for increasing Reynolds number regimes
Article
https://www.mdpi.com/2076-0825/11/12/359
34979636
Varela, P.; Suárez, P.; Alcántara, F.; Miro, A.; Rabault, J.; Font, B.; García, L.; Lehmkuhl, O.; Vinuesa, R.
Actuators
11
12, article 359
1
24
eprints
oai:upcommons.upc.edu:2117/1149032022-05-17T10:08:37Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Rodriguez, Ivette
Lehmkuhl Barba, Oriol
Piomelli, Ugo
Chiva, Jorge
Borrell, Ricard
Oliva, Assensi
Barcelona Supercomputing Center
2018-03-07T15:22:13Z
2018-12-01T01:31:03Z
2017-12
Rodriguez, I. [et al.]. LES-based Study of the Roughness Effects on the Wake of a Circular Cylinder from Subcritical to Transcritical Reynolds Numbers. "Flow, Turbulence and Combustion", Desembre 2017, vol. 99, núm. 3-4, p. 729-763.
1386-6184
http://hdl.handle.net/2117/114903
10.1007/s10494-017-9866-2
This paper investigates the effects of surface roughness on the flow past a circular cylinder at subcritical to transcritical Reynolds numbers. Large eddy simulations of the flow for sand grain roughness of size k/D = 0.02 are performed (D is the cylinder diameter). Results show that surface roughness triggers the transition to turbulence in the boundary layer at all Reynolds numbers, thus leading to an early separation caused by the increased momentum deficit, especially at transcritical Reynolds numbers. Even at subcritical Reynolds numbers, boundary layer instabilities are triggered in the roughness sublayer and eventually lead to the transition to turbulence. The early separation at transcritical Reynolds numbers leads to a wake topology similar to that of the subcritical regime, resulting in an increased drag coefficient and lower Strouhal number. Turbulent statistics in the wake are also affected by roughness; the Reynolds stresses are larger due to the increased turbulent kinetic energy production in the boundary layer and separated shear layers close to the cylinder shoulders.
We acknowledge “Red Española de Surpercomputación” (RES) for awarding us access to the MareNostrum III machine based in Barcelona, Spain (Ref. FI-2015-2-0026 and FI-2015-3-0011). We also acknowledge PRACE for awarding us access to Fermi and Marconi Supercomputers at Cineca, Italy (Ref. 2015133120). Oriol Lehmkuhl acknowledges a PDJ 2014 Grant by AGAUR (Generalitat de Catalunya). Ugo Piomelli acknowledges the support of the Natural Sciences and Engineering Research Council (NSERC) of Canada under the Discovery Grant Programme (Grant No. RGPIN-2016-04391). Ricard Borrell acknowledges a Juan de la Cierva postdoctoral grant (IJCI-2014-21034). Ivette Rodriguez, Oriol Lehmkuhl, Ricard Borrell and Assensi Oliva acknowledge Ministerio de Economía y Competitividad, Secretaría de Estado de Investigación, Desarrollo e Innovación, Spain (ref. ENE2014-60577-R).
Peer Reviewed
Postprint (author's final draft)
35 p.
eng
Springer Verlag
Àrees temàtiques de la UPC::Enginyeria elèctrica
Wakes (Fluid dynamics)
LES
Vortex shedding
Wakes
Roughness
Dinàmica de fluids
LES-based Study of the Roughness Effects on the Wake of a Circular Cylinder from Subcritical to Transcritical Reynolds Numbers
Article
https://link.springer.com/article/10.1007/s10494-017-9866-2
info:eu-repo/grantAgreement/MINECO//IJCI-2014-21034/ES/IJCI-2014-21034/
Open Access
Flow, Turbulence and Combustion
99
3-4
729
763
eprints
10.13039/501100003329
Ministerio de Economía y Competitividad
oai:upcommons.upc.edu:2117/3459282022-02-11T01:26:57Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Villamizar, Vianey
Grundvig, Dane
Rojas, Otilio
Acosta, Sebastian
Barcelona Supercomputing Center
2021-05-19T16:23:24Z
2022-02-11T01:26:57Z
2020
Villamizar, V. [et al.]. High order methods for acoustic scattering: Coupling farfield expansions ABC with deferred-correction methods. "Wave Motion", 2020, vol. 95, 102529.
0165-2125
http://hdl.handle.net/2117/345928
10.1016/j.wavemoti.2020.102529
Arbitrary high order numerical methods for time-harmonic acoustic scattering problems originally defined on unbounded domains are constructed. This is done by coupling recently developed high order local absorbing boundary conditions (ABCs) with finite difference methods for the Helmholtz equation. These ABCs are based on exact representations of the outgoing waves by means of farfield expansions. The finite difference methods, which are constructed from a deferred-correction (DC) technique, approximate the Helmholtz equation and the ABCs, with the appropriate number of terms, to any desired order. As a result, high order numerical methods with an overall order of convergence equal to the order of the DC schemes are obtained. A detailed construction of these DC finite difference schemes is presented. Additionally, a rigorous proof of the consistency of the DC schemes with the Helmholtz equation and the ABCs in polar coordinates is also given. The results of several numerical experiments corroborate the high order convergence of the novel method.
The first and third authors acknowledge the support provided by the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant No 777778 (MATHROCKS), and by the Office of Research and Creative Activities (ORCA) of Brigham Young University, United States of America. The work of S. Acosta was partially supported by National Science Foundation, United States of America [grant number DMS-1712725]. O. Rojas was also partially supported by the European Union’s Horizon 2020 research and innovation programme under the ChEESE project, grant agreement No. 823844.
Peer Reviewed
Postprint (author's final draft)
24 p.
eng
Elsevier
Attribution-NonCommercial-NoDerivs 3.0 Spain
http://creativecommons.org/licenses/by-nc-nd/3.0/es/
Open Access
Àrees temàtiques de la UPC::Informàtica::Aplicacions de la informàtica::Aplicacions informàtiques a la física i l‘enginyeria
High performance computing
Acoustic scattering
High order absorbing boundary conditions
Helmholtz equation
High order numerical methods
Deferred-correction methods
Càlcul intensiu (Informàtica)
Helmholtz, Equació de
High order methods for acoustic scattering: Coupling farfield expansions ABC with deferred-correction methods
Article
https://www.sciencedirect.com/science/article/abs/pii/S0165212519304202#!
102529
Wave Motion
95
eprints
oai:upcommons.upc.edu:2117/1170112021-09-27T11:24:19Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Sacco, Federica
Paun, Bruno
Lehmkuhl Barba, Oriol
Iles, Tinen L.
Iaizzo, Paul A.
Houzeaux, Guillaume
Vázquez, Mariano
Butakoff, Constantine
Aguado-Sierra, Jazmin
Barcelona Supercomputing Center
2018-05-08T10:24:17Z
2018-05-08T10:24:17Z
2018-04-30
Sacco, F. [et al.]. Left Ventricular Trabeculations Decrease the Wall Shear Stress and Increase the Intra-Ventricular Pressure Drop in CFD Simulations. "Frontiers in Physiology", 30 Abril 2018, vol. 9.
1664-042X
http://hdl.handle.net/2117/117011
10.3389/fphys.2018.00458
29760665
The aim of the present study is to characterize the hemodynamics of left ventricular (LV) geometries to examine the impact of trabeculae and papillary muscles (PMs) on blood flow using high performance computing (HPC). Five pairs of detailed and smoothed LV endocardium models were reconstructed from high-resolution magnetic resonance images (MRI) of ex-vivo human hearts. The detailed model of one LV pair is characterized only by the PMs and few big trabeculae, to represent state of art level of endocardial detail. The other four detailed models obtained include instead endocardial structures measuring ≥1 mm2 in cross-sectional area. The geometrical characterizations were done using computational fluid dynamics (CFD) simulations with rigid walls and both constant and transient flow inputs on the detailed and smoothed models for comparison. These simulations do not represent a clinical or physiological scenario, but a characterization of the interaction of endocardial structures with blood flow. Steady flow simulations were employed to quantify the pressure drop between the inlet and the outlet of the LVs and the wall shear stress (WSS). Coherent structures were analyzed using the Q-criterion for both constant and transient flow inputs. Our results show that trabeculae and PMs increase the intra-ventricular pressure drop, reduce the WSS and disrupt the dominant single vortex, usually present in the smoothed-endocardium models, generating secondary small vortices. Given that obtaining high resolution anatomical detail is challenging in-vivo, we propose that the effect of trabeculations can be incorporated into smoothed ventricular geometries by adding a porous layer along the LV endocardial wall. Results show that a porous layer of a thickness of 1.2·10−2 m with a porosity of 20 kg/m2 on the smoothed-endocardium ventricle models approximates the pressure drops, vorticities and WSS observed in the detailed models.
This paper has been partially funded by CompBioMed project, under H2020-EU.1.4.1.3 European Union’s Horizon 2020 research and innovation programme, grant agreement n◦ 675451. FS is supported by a grant from Severo Ochoa (n◦ SEV-2015-0493-16-4), Spain. CB is supported by a grant from the Fundació LaMarató de TV3 (n◦ 20154031), Spain. TI and PI are supported by the Institute of Engineering in Medicine, USA, and the Lillehei Heart Institute, USA.
Peer Reviewed
Postprint (published version)
15 p.
eng
Frontiers Media
Attribution-NonCommercial-NoDerivs 4.0 Spain
http://creativecommons.org/licenses/by-nc-nd/4.0/es/
Open Access
Àrees temàtiques de la UPC::Enginyeria biomèdica
Ventricular remodeling
Trabeculae
Papillary muscles
Left ventricular modeling
Left ventricular hemodynamics
Porosity
Cor--Ventricles
Left Ventricular Trabeculations Decrease the Wall Shear Stress and Increase the Intra-Ventricular Pressure Drop in CFD Simulations
Article
https://www.frontiersin.org/articles/10.3389/fphys.2018.00458/full
info:eu-repo/grantAgreement/EC/H2020/675451/EU/A Centre of Excellence in Computational Biomedicine/CompBioMed
info:eu-repo/grantAgreement/MINECO/PE2013-2016/SEV-2015-0493-16-4
Frontiers in Physiology
9
eprints
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/4054762024-03-27T16:10:14Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523
Soba, Alejandro
Fernandez Serracanta, Oriol
Lorenzo, Jose
Garcin, Diego
Houzeaux, Guillaume
Lamas, Neil
Granados, Xavier
Mantsinen, Mervi M.
Barcelona Supercomputing Center
2024-03-27T16:02:49Z
2024-04
2026-02-24
Soba, A. [et al.]. A high-performance electromagnetic code to simulate high-temperature superconductors. "Fusion Engineering and Design", Abril 2024, vol. 201, 114282.
0920-3796
http://hdl.handle.net/2117/405476
10.1016/j.fusengdes.2024.114282
Superconductivity is a physical phenomenon of some materials that allow them to conduct electrical current without resistance. This property has a wide range of applications. In particular, type-II high-temperature superconductors appear promising for building strong electromagnets carrying large amounts of current in the extreme conditions foreseen for future fusion reactors. However, their fabrication and related experiments are highly expensive and complex. Therefore, there is an increasing need for numerical models to guide the design optimization of superconducting cables and to predict their performance. In this work, we present a new code to simulate high-temperature superconductors (HTS) based on the edge finite element discretization of Maxwell’s equations in the time domain using the widely adopted H-formulation in the superconductor analysis community. This code is integrated in the High-Performance Computing (HPC) Alya suite and obtain an excellent performance up to 1024 processors in MareNostrum 4 supercomputer. This capacity allows to us to solve a wide variate of problems in big domains in relatively reduce amount of computer time, being a promising tool to aboard HTS coils design problems. Furthermore, validations against experimental data are presented and code results for superconducting tapes with different magnetic properties are analyzed.
This work is part of the FusionCAT project (001-P-001722) which has been 50% co-financed by the European Fund for Regional Development of the European Union within the framework of the 2014–2020 ERDF Operational Program of Catalonia, with the support of the Generalitat of Catalonia. In addition, it has been partly co-financed by grant PID2019-110854RB-I00 funded by MCIN/AEI/10.13039/501100011033 .
Peer Reviewed
Postprint (author's final draft)
eng
Elsevier
Attribution-NonCommercial-NoDerivatives 4.0 International
http://creativecommons.org/licenses/by-nc-nd/4.0/
Restricted access - publisher's policy
Àrees temàtiques de la UPC::Informàtica::Aplicacions de la informàtica::Aplicacions informàtiques a la física i l‘enginyeria
Superconductivity
High performance computing
Finite element analysis
Fusion magnets
H formulation
High-temperature superconductivity
HIgh-Performance Computing
Simulació per ordinador
A high-performance electromagnetic code to simulate high-temperature superconductors
Article
https://www.sciencedirect.com/science/article/pii/S0920379624001352
info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PID2019-110854RB-I00/ES/EVALUACION EXPERIMENTAL Y DESAROLLO DE CODIGOS DE MODELAJE PARA FUSION II/
114282
Fusion Engineering and Design
201
eprints
10.13039/501100011033
Agencia Estatal de Investigación
oai:upcommons.upc.edu:2117/3282112020-08-06T03:29:15Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Ratcliff, Laura E.
Dawson, William
Fisicaro, Giuseppe
Caliste, Damien
Mohr, Stephan
Degomme, Augustin
Videau, Brice
Cristiglio, Viviana
Stella, Martina
D’Alessandro, Marco
Goedecker, Stefan
Nakajima, Takahito
Deutsch, Thierry
Genovese, Luigi
Barcelona Supercomputing Center
2020-08-04T14:32:15Z
2020-08-04T14:32:15Z
2020
Ratcliff, L.E. [et al.]. Flexibilities of wavelets as a computational basis set for large-scale electronic structure calculations. "The Journal of Chemical Physics", 2020, vol. 152, núm. 19, 194110.
1089-7690
0021-9606
http://hdl.handle.net/2117/328211
10.1063/5.0004792
The BigDFT project was started in 2005 with the aim of testing the advantages of using a Daubechies wavelet basis set for Kohn–Sham (KS) density functional theory (DFT) with pseudopotentials. This project led to the creation of the BigDFT code, which employs a computational approach with optimal features of flexibility, performance, and precision of the results. In particular, the employed formalism has enabled the implementation of an algorithm able to tackle DFT calculations of large systems, up to many thousands of atoms, with a computational effort that scales linearly with the number of atoms. In this work, we recall some of the features that have been made possible by the peculiar properties of Daubechies wavelets. In particular, we focus our attention on the usage of DFT for large-scale systems. We show how the localized description of the KS problem, emerging from the features of the basis set, is helpful in providing a simplified description of large-scale electronic structure calculations. We provide some examples on how such a simplified description can be employed, and we consider, among the case-studies, the SARS-CoV-2 main protease.
We are thankful to Matthew Blakeley, Marco Zaccaria, and Massimo Reverberi for useful discussions. This work was supported by the Next-Generation Supercomputer Project (the K computer) and the FLAGSHIP2020 Project (Supercomputer Fugaku) within the priority study5 (Development of new fundamental technologies for high-efficiency energy creation, conversion/storage and use) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan. The calculations presented in Secs. VI B and IV H were performed using the Hokusai supercomputer system at RIKEN and analyzed using the Grid’5000 testbed, supported by a scientific interest group hosted by Inria and including CNRS, RENATER, and several Universities as well as other organizations (see https://www.grid5000.fr). Computer resources for the anatase TiO2 (1 0 1) surface were provided by the Swiss National Supercomputing Centre (CSCS) under Project No. s869. All other large scale calculations were performed using the ARCHER UK National Supercomputing Service through Grant No. EP/P033253/1. Computer resources on the SARS-CoV-2 main protease analysis were provided by CEA and GENCI though discretionary allocation. We are also thankful to C. Menache and the CEA team for the kind support. L.G., T.N., and W.D. also gratefully acknowledge the joint CEA-RIKEN collaboration action. We also acknowledge support from the MaX Center of Excellence. L.E.R. and M.S. acknowledge support from an EPSRC Early Career Research Fellowship (EP/P033253/1) and the Thomas Young Centre under Grant No. TYC-101.
Peer Reviewed
Postprint (author's final draft)
31 p.
eng
AIP Publishing
Àrees temàtiques de la UPC::Informàtica::Aplicacions de la informàtica::Aplicacions informàtiques a la física i l‘enginyeria
Wavelets (Mathematics)
Algorithms
Density functionals
Quantum chemistry
Computer simulation
Wavelets
Density functional theory (DFT)
Atoms
Daubechies wavelets
Large-scale systems
SARS-CoV-2
Electronic structure simulations
Àtoms
Algorismes
Simulació per ordinador
Flexibilities of wavelets as a computational basis set for large-scale electronic structure calculations
Article
https://aip.scitation.org/doi/full/10.1063/5.0004792
Open Access
194110
The Journal of Chemical Physics
152
19
eprints
oai:upcommons.upc.edu:2117/3556562021-12-09T11:46:24Zcom_2117_79677com_2117_28579com_2117_28577com_2117_98851com_2117_28581com_2117_80515com_2117_23714com_2117_28578com_2117_15797col_2117_79695col_2117_103655col_2117_80523col_2117_3055openAccess
Terzic, Elena
Miró Jané, Arnau
Organelli, Emanuele
Kowalczuk, Piotr
D'Ortenzio, Fabrizio
Lazzari, Paolo
Universitat Politècnica de Catalunya. Departament de Física
Barcelona Supercomputing Center
Universitat Politècnica de Catalunya. TUAREG - Turbulence and Aerodynamics in Mechanical and Aerospace Engineering Research Group
2021-11-04T17:23:20Z
2021-11-04T17:23:20Z
2021-10-04
Terzic, E. [et al.]. Radiative transfer modeling with BGC-Argo float data in the Mediterranean Sea. "Journal of geophysical research: oceans", 4 Octubre 2021, vol. 126, núm. 10, p. 1-22.
2169-9291
http://hdl.handle.net/2117/355656
10.1029/2021JC017690
A radiative transfer model was parameterized and validated using Biogeochemical Argo float data acquired between 2012 and 2017 across the Mediterranean Sea. Fluorescence-derived chlorophyll urn:x-wiley:21699275:media:jgrc24745:jgrc24745-math-0001 concentration, particulate optical backscattering at 700 nm, and fluorescence of chromophoric dissolved organic matter (CDOM) were used to parametrize the light absorption and scattering coefficients of the optically significant water constituents (such as pure water, non-algal particles, CDOM, and phytoplankton). The model was validated with in situ downwelling irradiance profiles and apparent optical properties derived both from irradiance profiles and satellite data, such as the diffuse attenuation coefficients and remote sensing reflectance. Results showed that by using regional parameterizations that are not only related to chlorophyll concentration and vertical distribution, the model was able to capture a more accurate spectral response in the examined wavelength range compared to chlorophyll-related (or Case 1) optical models. When using alternative models that incorporated also measurements of CDOM fluorescence or particulate optical backscattering, the model skill increased at all examined wavelengths. Finally, using a multi-spectral optical configuration also enabled the estimation of the relative contribution of separate water constituents in the examined spectral range. Simulations including non-algal particles and CDOM performed up to 61% and 79% better than when considering the optical properties of pure seawater alone. Moreover, a simulation including phytoplankton light absorption resulted in an error reduction of up to 42%, especially at 412 nm and with a more uniform response at the wavelengths considered.
This work was performed within the framework of the BIOPTIMOD CMEMS Service Evolution project. CMEMS is implemented by Mercator Ocean International within the framework of a delegation agreement with the European Union. This study was supported by the following research projects funding BGC-Argo floats: NAOS (funded by the Agence Nationale de la Recherche in the frame of the French “Equipement d’avenir” program, grant agreement ANR J11R107-F), remOcean (funded by the ,European Research Council grant agreement 246777), Argo-Italy (funded by the Italian Ministry of Education, University and Research), and the French Bio-Argo program (Bio-Argo France; funded by CNES-TOSCA, LEFE Cyber, and GMMC). The authors would especially like to thank Giorgio Bolzon for his invaluable help and IT support in data management, as well as development of codes and libraries to analyze float and satellite products. Special thanks also to Ilya Chernov (Russian Academy of Science) for his contribution in developing the RT model.
Peer Reviewed
Postprint (published version)
22 p.
eng
Wiley
https://creativecommons.org/licenses/by-nc-nd/4.0/
http://creativecommons.org/licenses/by-nc-nd/4.0/
Open Access
Àrees temàtiques de la UPC::Física
Mediterranean Sea
Radiative transfer
Light--Scattering
Marine biology
Mediterrània, Mar
Transferència radiativa
Llum -- Difusió
Biologia marina
Radiative transfer modeling with BGC-Argo float data in the Mediterranean Sea
Article
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021JC017690
30264414
Terzic, E.; Miro, A.; Organelli, E.; Kowalczuk, P.; D'Ortenzio, F.; Lazzari, P.
Journal of geophysical research: oceans
126
10
1
22
eprints
oai:upcommons.upc.edu:2117/1328752020-09-15T00:26:33Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Houzeaux, Guillaume
Borrell, Ricard
Cajas García, Juan Carlos
Vázquez, Mariano
Barcelona Supercomputing Center
2019-05-10T14:08:31Z
2020-09-15T00:26:33Z
2018-09-15
Houzeaux, G. [et al.]. Extension of the parallel Sparse Matrix Vector Product (SpMV) for the implicit coupling of PDEs on non-matching meshes. "Computers & Fluids", 15 Setembre 2018, vol. 173, p. 216-225.
0045-7930
http://hdl.handle.net/2117/132875
10.1016/j.compfluid.2018.03.006
The Sparse Matrix Vector Product (SpMV) is one of the main operations of iterative solvers, and, in a parallel context, it is also the siege of point-to-point communications between the neighboring MPI processes. The parallel SpMV is built in such a way that it gives, up to round off errors, the same result as its sequential counterpart. In this regards, nodes on the interfaces (or halo nodes if halo are considered) are duplicated nodes of the same original mesh. It is therefore limited to matching meshes. In this work, we generalize the parallel SpMV to glue the solution of non-matching (non-conforming) meshes through the introduction of transmission matrices. This extension of the SpMV thus enables the implicit and parallel solution of partial differential equations on non-matching meshes, as well as the implicit coupling of multiphysics problems, such as fluid-structure interactions. The proposed method is developed similarly to classical parallelization techniques and can therefore be implemented by modifying few subroutines of an already MPI-based code. According to the proposed framework, the classical parallelization technique appears as a particular case of this general setup.
Peer Reviewed
Postprint (author's final draft)
10 p.
eng
Elsevier
Àrees temàtiques de la UPC::Enginyeria mecànica
High performance computing
Parallel sparse-matrix vector product
SpMV
MPI
Parallelization
Non-matching meshes
Coupling
Supercomputadors
Extension of the parallel Sparse Matrix Vector Product (SpMV) for the implicit coupling of PDEs on non-matching meshes
Article
https://www.sciencedirect.com/science/article/abs/pii/S0045793018301099
Open Access
Computers & Fluids
173
216
225
eprints
oai:upcommons.upc.edu:2117/847692020-07-23T23:27:46Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Peredo, Oscar
Ortiz, Julián M.
Herrero, José R.
Samaniego, Cristóbal
Barcelona Supercomputing Center
2016-03-23T10:39:00Z
2016-05-02T00:31:03Z
2014-05
Peredo, Oscar [et al.]. Tuning and hybrid parallelization of a genetic-based multi-point statistics simulation code. "Parallel Computing", Maig 2014, vol. 40, núm. 5-6, p. 144-158.
0167-8191
http://hdl.handle.net/2117/84769
10.1016/j.parco.2014.04.005
One of the main difficulties using multi-point statistical (MPS) simulation based on annealing techniques or genetic algorithms concerns the excessive amount of time and memory that must be spent in order to achieve convergence. In this work we propose code optimizations and parallelization schemes over a genetic-based MPS code with the aim of speeding up the execution time. The code optimizations involve the reduction of cache misses in the array accesses, avoid branching instructions and increase the locality of the accessed data. The hybrid parallelization scheme involves a fine-grain parallelization of loops using a shared-memory programming model (OpenMP) and a coarse-grain distribution of load among several computational nodes using a distributed-memory programming model (MPI). Convergence, execution time and speed-up results are presented using 2D training images of sizes 100 × 100 × 1 and 1000 × 1000 × 1 on a distributed-shared memory supercomputing facility.
Peer Reviewed
Postprint (author's final draft)
15 p.
eng
Elsevier
Attribution-NonCommercial-NoDerivs 4.0 International License
https://creativecommons.org/licenses/by-nc-nd/4.0/
Open Access
Àrees temàtiques de la UPC::Enginyeria biomèdica
Simulation methods
Genetic algorithms
Geostatistics
Stochastic simulation
Multi-point statistics
Code optimization
Parallel computing
Genetic algorithms
Simulació, Mètodes de
Genètica
Tuning and hybrid parallelization of a genetic-based multi-point statistics simulation code
Article
http://www.sciencedirect.com/science/article/pii/S0167819114000489
Parallel Computing
40
5-6
144
158
eprints
oai:upcommons.upc.edu:2117/3423022023-03-16T01:26:55Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Soba, Alejandro
Cazado, Mauricio E.
Houzeaux, Guillaume
Gutierrez Milla, Albert
Mantsinen, Mervi J.
Saez Pous, Xavier
Barcelona Supercomputing Center
2021-03-23T15:45:14Z
2023-03-16T01:26:55Z
2021
Soba, A. [et al.]. Validations of the radiation transport module NEUTRO: A deterministic solver for the neutron transport equation. "Fusion Engineering and Design", 2021, vol. 169, 112497.
0920-3796
http://hdl.handle.net/2117/342302
10.1016/j.fusengdes.2021.112497
We present significant improvements and validations of a deterministic neutron transport code (NEUTRO) dedicated to solving the Boltzmann Transport Equation. The code is integrated as a module in the Alya software package developed by the Barcelona Supercomputing Center which uses the Discrete Ordinates Method on angular coordinates, multi-group for energy discretization and FEM on unstructured meshes to treat special complex domains. The anisotropy of the scattering medium is introduced into the scattering kernel using real base expressions for spherical harmonics. In order to build the total cross-section and the respective group matrix for the elastic cross-section, we use the NJOY code. We test the solver using different geometries, orders of integration for the angular discretization and number of energy groups. Finally, we compare our results against benchmarks obtained from an NEA database that reported measurements of leakage spectra of several materials.
This work has been partially carried out within the framework of the EUROlab4HPC and Severo Ochoa fellowship and has been partly co-financed by the European Union Regional Development Fund (ERDF) within the framework of the ERDF Operational Program of Catalonia 2014-2020. The authors would like to thank Dr A. Portone and Dr M. Fabbri for useful discussions.
Peer Reviewed
Postprint (author's final draft)
12 p.
eng
Elsevier
Attribution-NonCommercial-NoDerivs 3.0 Spain
http://creativecommons.org/licenses/by-nc-nd/3.0/es/
Open Access
Àrees temàtiques de la UPC::Física
Boltzmann transport equation
Neutron transport theory
High performance computing
Radiation transport
Neutron-wall interaction
Fusion reactors shielding
SINBAD
Fusió nuclear
Validations of the radiation transport module NEUTRO: A deterministic solver for the neutron transport equation
Article
https://www.sciencedirect.com/science/article/abs/pii/S0920379621002738#!
112497
Fusion Engineering and Design
169
eprints
oai:upcommons.upc.edu:2117/850232020-07-23T23:27:47Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Eriksson, Johan
Scopus - Author details - Nocente, Massimo
Binda, Federico
Scopus - Author details - Cazzaniga, Carlo
Conroy, Sean W.
Ericsson, Göran N.
Giacomelli, Luca C.
Gorini, Giuseppe
Hellesen, Carl
Hellsten, Törbjrn
Hjalmarsson, Anders
Jacobsen, Arnhild S.
Johnson, Thomas
Kiptily, Vasily
Koskela, Tuomas
Mantsinen, Mervi
Salewski, Mirko
Schneider, Michael
Sharapov, Sergei
Skiba, Mateusz
Tardocchi, Marco
Weiszflog, Matthias
Barcelona Supercomputing Center
2016-03-31T16:08:31Z
2016-11-19T01:30:27Z
2015-11-19
Eriksson, Johan [et al.]. Dual sightline measurements of MeV range deuterons with neutron and gamma-ray spectroscopy at JET. "Nuclear Fusion", 19 Novembre 2015, vol. 55, núm. 12.
0029-5515
http://hdl.handle.net/2117/85023
10.1088/0029-5515/55/12/123026
Observations made in a JET experiment aimed at accelerating deuterons to the MeV range by third harmonic radio-frequency (RF) heating coupled into a deuterium beam are reported. Measurements are based on a set of advanced neutron and gamma-ray spectrometers that, for the first time, observe the plasma simultaneously along vertical and oblique lines of sight. Parameters of the fast ion energy distribution, such as the high energy cut-off of the deuteron distribution function and the RF coupling constant, are determined from data within a uniform analysis framework for neutron and gamma-ray spectroscopy based on a one-dimensional model and by a consistency check among the individual measurement techniques. A systematic difference is seen between the two lines of sight and is interpreted to originate from the sensitivity of the oblique detectors to the pitch-angle structure of the distribution around the resonance, which is not correctly portrayed within the adopted one dimensional model. A framework to calculate neutron and gamma-ray emission from a spatially resolved, two-dimensional deuteron distribution specified by energy/pitch is thus developed and used for a first comparison with predictions from ab initio models of RF heating at multiple harmonics.
The results presented in this paper are of relevance for the development of advanced diagnostic techniques for MeV range ions in high performance fusion plasmas, with applications to the experimental validation of RF heating codes and, more generally, to studies of the energy distribution of ions in the MeV range in high performance deuterium and deuterium-tritium plasmas.
This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014-2018
under grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of the European
Commission.
Postprint (author's final draft)
eng
Institute of Physics Publishing (IOP)
Àrees temàtiques de la UPC::Enginyeria biomèdica
Gamma ray spectrometer
Gamma rays--Measurement
Radio frequency identification systems
Fusion
Tokamak
Fast ions
Neutron spectrometry
Gamma-ray spectroscopy
Plasma and Space Physics
Espectrometria de raigs gamma
Dual sightline measurements of MeV range deuterons with neutron and gamma-ray spectroscopy at JET
Article
http://iopscience.iop.org/article/10.1088/0029-5515/55/12/123026/meta;jsessionid=2EAA730D9B58D778CF1C1CFE5EC1B181.c2
info:eu-repo/grantAgreement/EC/H2020/633053/EU/Implementation of activities described in the Roadmap to Fusion during Horizon 2020 through a Joint programme of the members of the EUROfusion consortium/EUROfusion
Open Access
Nuclear Fusion
55
12
123026
eprints
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/1086702020-07-23T23:27:47Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Mohr, Stephan
Masella, Michel
Ratcliff, Laura E.
Genovese, Luigi
Barcelona Supercomputing Center
2017-10-13T08:38:44Z
2018-07-21T00:30:29Z
2017-07-21
Mohr, S. [et al.]. Complexity Reduction in Large Quantum Systems: Fragment Identification and Population Analysis via a Local Optimized Minimal Basis. "Journal of Chemical Theory and Computation", 21 Juliol 2017, vol. 13, núm. 9, p. 4079-4088.
1549-9618
http://hdl.handle.net/2117/108670
10.1021/acs.jctc.7b00291
We present, within Kohn–Sham density functional theory calculations, a quantitative method to identify and assess the partitioning of a large quantum-mechanical system into fragments. We then show how within this framework simple generalizations of other well-known population analyses can be used to extract, from first-principles, reliable electrostatic multipoles for the identified fragments. Our approach reduces arbitrariness in the fragmentation procedure and enables the possibility to assess quantitatively whether the corresponding fragment multipoles can be interpreted as observable quantities associated with a system moiety. By applying our formalism within the code BigDFT, we show that the use of a minimal set of in situ-optimized basis functions allows at the same time a proper fragment definition and an accurate description of the electronic structure.
We would like to thank Thierry Deutsch for valuable discussions and Fátima Lucas for providing various test systems and helpful discussions. This research used resources
of the Argonne Leadership Computing Facility,
which is a DOE Office of Science User Facility supported under Contract DEAC02-06CH11357. SM acknowledges
support from the European Centre of Excellence MaX (project ID 676598). LG acknowledges support from the EU ExtMOS project (project ID 646176) and the European
Centre of Excellence EoCoE (project ID 676629).
Peer Reviewed
Postprint (author's final draft)
12 p.
eng
American Chemical Society
Attribution-NonCommercial-NoDerivs 3.0 Spain
http://creativecommons.org/licenses/by-nc-nd/3.0/es/
Open Access
Àrees temàtiques de la UPC::Enginyeria electrònica
Quantum mechanics
Atoms
Density functional theory
Large quantum-mechanical system
BigDFT
Quàntums, Teoria dels
Àtoms
Complexity Reduction in Large Quantum Systems: Fragment Identification and Population Analysis via a Local Optimized Minimal Basis
Article
http://pubs.acs.org/doi/abs/10.1021/acs.jctc.7b00291
info:eu-repo/grantAgreement/EC/H2020/676598/EU/Materials design at the eXascale/MaX
info:eu-repo/grantAgreement/EC/H2020/646176/EU/EXTended Model of Organic Semiconductors/EXTMOS
info:eu-repo/grantAgreement/EC/H2020/676629/EU/Energy oriented Centre of Excellence for computer applications/EoCoE
Journal of Chemical Theory and Computation
13
9
4079
4088
eprints
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3647222022-03-27T15:52:01Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Cervera Lierta, Alba
Krenn, Mario
Aspuru Guzik, Alán
Galda, Alexey
Barcelona Supercomputing Center
2022-03-22T10:30:50Z
2022-03-22T10:30:50Z
2022-02
Cervera Lierta, A. [et al.]. Experimental high-dimensional Greenberger-Horne-Zeilinger entanglement with superconducting transmon Qutrits. "Physical Review Applied", Febrer 2022, vol. 17, 024062.
2331-7019
http://hdl.handle.net/2117/364722
10.1103/PhysRevApplied.17.024062
Multipartite entanglement is one of the core concepts in quantum information science with broad applications that span from condensed matter physics to quantum physics foundation tests. Although its most studied and tested forms encompass two-dimensional systems, current quantum platforms technically allow the manipulation of additional quantum levels. We report the experimental demonstration and certification of a high-dimensional multipartite entangled state in a superconducting quantum processor. We generate the three-qutrit Greenberger-Horne-Zeilinger state by designing the necessary pulses to perform high-dimensional quantum operations. We obtain the fidelity of 76%±1%, proving the generation of a genuine three-partite and three-dimensional entangled state. To this date, only photonic devices have been able to create and certify the entanglement of these high-dimensional states. Our work demonstrates that another platform, superconducting systems, is ready to exploit genuine high-dimensional entanglement and that a programmable quantum device accessed on the cloud can be used to design and execute experiments beyond binary quantum computation.
We acknowledge the use of IBM Quantum services for this work. We acknowledge the access to advanced services provided by the IBM Quantum Researchers Program, and also the IBM Quantum Researcher Access Award Program. M.K. and A.C.L appreciate Manuel Erhard’s insights on high-dimensional entanglement. A.A.-G. acknowledges the generous support from Google, Inc. in the form of a Google Focused Award. This work was supported by the U.S. Department of Energy under Award No. DESC0019374 and the U.S. Office of Naval Research (ONS506661). A.A.-G. also acknowledges support from the Canada Industrial Research Chairs Program and the Canada 150 Research Chairs Program. M.K. acknowledges support from the FWF (Austrian Science Fund) via the Erwin Schr¨odinger fellowship No. J4309
Peer Reviewed
Postprint (author's final draft)
15 p.
eng
American Physical Society
Àrees temàtiques de la UPC::Informàtica::Aplicacions de la informàtica::Aplicacions informàtiques a la física i l‘enginyeria
Quantum computing.
Quantum information science
Greenberger-Horne-Zeilinger
Superconducting qubits
Quàntums, Teoria dels
Experimental high-dimensional Greenberger-Horne-Zeilinger entanglement with superconducting transmon Qutrits
Article
https://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.17.024062
Open Access
024062
Physical Review Applied
17
eprints
oai:upcommons.upc.edu:2117/3665372022-12-08T01:26:01Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Navarro Acero, Pablo
Mohr, Stephan
Bernabei, Marco
Fernández, Carlos
Domínguez, Beatriz
Ewen, James
Barcelona Supercomputing Center
2022-04-28T14:42:12Z
2022-12-08T01:26:01Z
2021-12
Navarro Acero, P. [et al.]. Molecular simulations of surfactant adsorption on Iron oxide from hydrocarbon solvents. "Langmuir", Desembre 2021, vol. 37, núm. 50, p. 14582-14596.
0743-7463
http://hdl.handle.net/2117/366537
10.1021/acs.langmuir.1c02133
The performance of organic friction modifiers (OFMs) depends on their ability to adsorb onto surfaces and form protective monolayers. Understanding the relationship between OFM concentration in the base oil and the resulting surface coverage is important for improving lubricant formulations. Here, we use molecular dynamics (MD) simulations to study the adsorption of three OFMs─stearic acid (SA), glycerol monoostearate (GMS), and glycerol monooleate (GMO)─onto a hematite surface from two hydrocarbon solvents─n-hexadecane and poly(α-olefin) (PAO). We calculate the potential of mean force of the adsorption process using the adaptive biasing force algorithm, and the adsorption strength increases in the order SA < GMS < GMO. We estimate the minimum area occupied by OFM molecules on the surface using annealing MD simulations and obtained a similar hard-disk area for GMS and GMO but a lower value for SA. Using the MD results, we determine the adsorption isotherms using the molecular thermodynamic theory (MTT), which agree well with one previous experimental data set for SA on hematite. For two other experimental data sets for SA, lateral interactions between surfactant molecules need to be accounted for within the MTT framework. SA forms monolayers with lower surface coverage than GMO and GMS at low concentrations but also has the highest plateau coverage. We validate the adsorption energies from the MD simulations using high-frequency reciprocating rig friction experiments with different concentrations of the OFMs in PAO. For OFMs with saturated tailgroups (SA and GMS), we obtain good agreement between the simulations and the experiments. The results deviate for OFMs containing Z-unsaturated tailgroups (GMO) due to the additional steric hindrance, which is not accounted for in the current simulation framework. This study demonstrates that MD simulations, alongside MTT, are an accurate and efficient tool to predict adsorption isotherms at solid–liquid interfaces.
ll authors thank the Repsol Foundation and the Repsol Technology Lab for financial support. We acknowledge the Partnership for Advanced Computing in Europe (PRACE) scheme for awarding us access to the J ̈ulich Wizard for European Leadership Science (JUWELS)
system, Gauss Centre for Supercomputing at the Forschungszentrum J ̈ulich (GCS@FZJ), Germany.103 J.P.E. was supported by the Royal Academy of Engineering under the Research Fellowship scheme.
Peer Reviewed
Postprint (author's final draft)
15 p.
eng
American Chemical Society
https://pubs.acs.org/doi/10.1021/acs.langmuir.1c02133?goto=supporting-info
https://pubs.acs.org/doi/full/10.1021/acs.langmuir.1c02133
Àrees temàtiques de la UPC::Informàtica::Aplicacions de la informàtica::Aplicacions informàtiques a la física i l‘enginyeria
Molecular dynamics
Surfactants
Adsorption
Friction
Solvents
Molecules
Lubrificació i lubrificants
Simulació per ordinador
Molecular simulations of surfactant adsorption on Iron oxide from hydrocarbon solvents
Article
Open Access
Langmuir
37
50
14582
14596
eprints
oai:upcommons.upc.edu:2117/1002792020-07-23T23:27:47Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Garcia, J.
Challis, C.
Gallart, D.
Garzotti, L.
Görler, T.
King, D.
Mantsinen, Mervi
Jet Contributors
Barcelona Supercomputing Center
2017-01-30T11:54:01Z
2017-01-30T11:54:01Z
2016-10-27
Garcia, J. [et al.]. Challenges in the extrapolation from DD to DT plasmas: experimental analysis and theory based predictions for JET-DT. "Plasma Physics and Controlled Fusion", 27 Octubre 2016, vol. 59, núm. 1.
0741-3335
http://hdl.handle.net/2117/100279
A strong modelling program has been started in support of the future JET-DT campaign with the aim of guiding experiments in deuterium (D) towards maximizing fusion energy production in Deuterium–Tritium (DT). Some of the key elements have been identified by using several of the most updated and sophisticated models for predicting heat and particle transport, pedestal pressure and heating sources in an integrated modelling framework. For the high beta and low gas operational regime, the density plays a critical role and a trend towards higher fusion power is obtained at lower densities. Additionally, turbulence stabilization by E × B flow shear is shown to generate an isotope effect leading to higher confinement for DT than DD and therefore plasmas with high torque are suitable for maximizing fusion performance. Future JET campaigns will benefit from this modelling activity by defining clear priorities on their scientific program.
This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014–2018
under grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission.
Peer Reviewed
Postprint (published version)
7 p.
eng
IOP Publishing
Àrees temàtiques de la UPC::Enginyeria biomèdica
Plasma control
Fusion Energy Conference
Fusion reactions, Controlled
Plasma
Tokamak
Integrated modeling
Tècniques de plasma
Fusió nuclear
Challenges in the extrapolation from DD to DT plasmas: experimental analysis and theory based predictions for JET-DT
Article
http://iopscience.iop.org/article/10.1088/0741-3335/59/1/014023/meta
info:eu-repo/grantAgreement/EC/H2020/633053/EU/Implementation of activities described in the Roadmap to Fusion during Horizon 2020 through a Joint programme of the members of the EUROfusion consortium/EUROfusion
Open Access
Special issue featuring the invited talks from the 43rd EPS Conference on Plasma Physics, Leuven, 4-8 July 2016
Plasma Physics and Controlled Fusion
59
1
eprints
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3419062021-03-21T19:31:12Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Prisco, Anthony R.
Aguado Sierra, Jazmín
Butakoff, Constantine
Vázquez, Mariano
Houzeaux, Guillaume
Eguzkitza, Beatriz
Bartos, Jason A.
Yannopoulos, Demetris
Raveendran, Ganesh
Holm, Mikayle
Iles, Tinen
Mahr, Claudius
Iaizzo, Paul A.
Barcelona Supercomputing Center
2021-03-17T17:18:12Z
2021-03-17T17:18:12Z
2021
Prisco, A.R. [et al.]. Concomitant respiratory failure can impair myocardial oxygenation in patients with acute cardiogenic shock supported by VA-ECMO. "Journal of Cardiovascular Translational Research", 2021,
1937-5387
http://hdl.handle.net/2117/341906
10.1007/s12265-021-10110-2
33624260
Venous-arterial extracorporeal membrane oxygenation (VA-ECMO) treatment for acute cardiogenic shock in patients who also have acute lung injury predisposes development of a serious complication called “north-south syndrome” (NSS) which causes cerebral hypoxia. NSS is poorly characterized and hemodynamic studies have focused on cerebral perfusion ignoring the heart. We hypothesized in NSS the heart would be more likely to receive hypoxemic blood than the brain due to the proximity of the coronary arteries to the aortic annulus. To test this, we conducted a computational fluid dynamics simulation of blood flow in a human supported by VA-ECMO. Simulations quantified the fraction of blood at each aortic branching vessel originating from residual native cardiac output versus VA-ECMO. As residual cardiac function was increased, simulations demonstrated myocardial hypoxia would develop prior to cerebral hypoxia. These results illustrate the conditions where NSS will develop and the relative cardiac function that will lead to organ-specific hypoxia.
This work was supported in part by the University of Minnesota’s Medical School Academic Investment Education Program grant and the Institute for Engineering in Medicine. We also acknowledge the Partnership for Advanced Computing in Europe (PRACE) for awarding us access to Joliot-Curie Rome supercomputer at Bruyères-le-Châtel, under the project Cardiovascular-COVID. Additionally, we would like to acknowledge the Torres Quevedo Program, the Ramón y Cajal Program, and the European Institute of Innovation and Technology for support.
Peer Reviewed
Postprint (published version)
10 p.
eng
Springer Link
Attribution 3.0 Spain
http://creativecommons.org/licenses/by/3.0/es/
Open Access
Àrees temàtiques de la UPC::Enginyeria biomèdica
Blood -- Circulation
Venous arteries
Computer simulation
VA-ECMO
Acute respiratory distress syndrome
North-south syndrome
Computational fluid dynamics
Sang -- Circulació
Simulació per ordinador
Concomitant respiratory failure can impair myocardial oxygenation in patients with acute cardiogenic shock supported by VA-ECMO
Article
https://link.springer.com/article/10.1007%2Fs12265-021-10110-2
info:eu-repo/grantAgreement/MINECO/2PE/RYC-2017-22532
info:eu-repo/grantAgreement/EC/H2020/823712/EU/A Centre of Excellence in Computational Biomedicine/CompBioMed2
Journal of Cardiovascular Translational Research
eprints
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3458402021-05-18T14:00:51Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Kalha, Curran
Fernando, Nathalie Kanchena
Berens, Judith
Gutierrez Moreno, Jose Julio
Mohr, Stephan
Barcelona Supercomputing Center
2021-05-18T13:55:48Z
2021-05-18T13:55:48Z
2021
Kalha, C. [et al.]. Thermal and oxidation stability of TixW1−x diffusion barriers investigated by soft and hard x-ray photoelectron spectroscopy. "Journal of Applied Physics", 2021, vol. 129, núm. 19, 195302.
0021-8979
1089-7550
http://hdl.handle.net/2117/345840
10.1063/5.0048304
The binary alloy of titanium-tungsten (TiW) is an established diffusion barrier in high-power semiconductor devices, owing to its ability to suppress the diffusion of copper from the metallization scheme into the surrounding silicon substructure. However, little is known about the response of TiW to high-temperature events or its behavior when exposed to air. Here, a combined soft and hard x-ray photoelectron spectroscopy (XPS) characterization approach is used to study the influence of post-deposition annealing and titanium concentration on the oxidation behavior of a 300 nm-thick TiW film. The combination of both XPS techniques allows for the assessment of the chemical state and elemental composition across the surface and bulk of the TiW layer. The findings show that in response to high-temperature annealing, titanium segregates out of the mixed metal system and upwardly migrates, accumulating at the TiW/air interface. Titanium shows remarkably rapid diffusion under relatively short annealing timescales, and the extent of titanium surface enrichment is increased through longer annealing periods or by increasing the bulk titanium concentration. Surface titanium enrichment enhances the extent of oxidation both at the surface and in the bulk of the alloy due to the strong gettering ability of titanium. Quantification of the soft x-ray photoelectron spectra highlights the formation of three tungsten oxidation environments, attributed to WO2, WO3, and a WO3 oxide coordinated with a titanium environment. This combinatorial characterization approach provides valuable insights into the thermal and oxidation stability of TiW alloys from two depth perspectives, aiding the development of future device technologies.
C.K. acknowledges the support from the Department of Chemistry, UCL. N.K.F. acknowledges support from the Engineering and Physical Sciences Research Council (No. EP/L015277/1). J.J.G.M. and S.M. acknowledge the support from the FusionCAT project (No. 001-P-001722) co-financed by the European Union Regional Development Fund within the framework of the ERDF Operational Program of Catalonia 2014–2020 with a grant of 50% of total cost eligible, the access to computational resources at MareNostrum and the technical support provided by BSC (No. RES-QS-2020-3-0026). L.E.R. acknowledges support from an EPSRC Early Career Research Fellowship (No. EP/P033253/1) and the Thomas Young Centre under Grant No. TYC-101. A.R. acknowledges the support from the Analytical Chemistry Trust Fund for her CAMS-UK Fellowship. We acknowledge Diamond Light Source for time on Beamline I09 under Proposal No. SI19885-1. The authors would like to thank Dave McCue, I09 beamline technician, for his support of the experiments.
Peer Reviewed
Postprint (author's final draft)
"Article signat per 13 autors/es: C. Kalha, S. Bichelmaier, N. K. Fernando, J. V. Berens, P. K. Thakur, T.-L. Lee, J. J. Gutiérrez Moreno, S. Mohr, L. E. Ratcliff, M. Reisinger, J. Zechner, M. Nelhiebel, and A. Regoutz"
15 p.
eng
American Institute of Physics
https://aip.scitation.org/doi/suppl/10.1063/5.0048304
https://aip.scitation.org/doi/10.1063/5.0048304
https://nomad-lab.eu/prod/rae/gui/dataset/id/n7Q2rvmFTUKaOw9B_KwD3Q
Àrees temàtiques de la UPC::Física
Alloys
X-ray photoelectron spectroscopy.
Titanium alloys
Alloys
Annealing
X-ray photoelectron spectroscopy
Depth profiling techniques
Metallization process
Microfabrication
Density functional theory
Diffusion barriers
Semiconductor devices
Semiconductors
Thermal and oxidation stability of TixW1−x diffusion barriers investigated by soft and hard x-ray photoelectron spectroscopy
Article
Open Access
195302
Journal of Applied Physics
129
19
eprints
oai:upcommons.upc.edu:2117/3938862023-10-26T10:22:13Zcom_2117_79677com_2117_28579com_2117_28577com_2117_98851com_2117_28581com_2117_3989com_2117_80515com_2117_23714com_2117_28578com_2117_184576com_2117_184544com_2117_15797col_2117_79695col_2117_103655col_2117_3990col_2117_80523col_2117_184713col_2117_3055openAccess
Miró Jané, Arnau
Eiximeno Franch, Benet
Rodríguez Pérez, Ivette María
Lehmkuhl Barba, Oriol
Universitat Politècnica de Catalunya. Departament de Física
Universitat Politècnica de Catalunya. Doctorat en Física Computacional i Aplicada
Universitat Politècnica de Catalunya. Departament de Màquines i Motors Tèrmics
Barcelona Supercomputing Center
Universitat Politècnica de Catalunya. TUAREG - Turbulence and Aerodynamics in Mechanical and Aerospace Engineering Research Group
2023-09-22T07:14:01Z
2023-09-22T07:14:01Z
2023-09-14
Miro, A. [et al.]. Self-induced large-scale motions in a three-dimensional diffuser. "Flow turbulence and combustion", 14 Setembre 2023, p. 1-18.
1386-6184
http://hdl.handle.net/2117/393886
10.1007/s10494-023-00483-6
A direct numerical simulation of a three-dimensional diffuser at Reynolds number Re = 10,000 (based on inlet bulk velocity) has been performed using a low-dissipation finite element code. The geometry chosen for this work is the Stanford diffuser, introduced by Cherry et al. (Int. J. Heat Fluid Flow 29:803–811, 2008). Results have been exhaustively compared with the published data with a quite good agreement. Additionally, further turbulent statistics have been provided such as the Reynolds stresses or the turbulent kinetic energy. A proper orthogonal decomposition and a dynamic mode decomposition analyses of the main flow variables have been performed to identify the main characteristics of the large-scale motions. A combined, self-induced movement of the large-scales has been found to originate in the top-right expansion corner with two clear features. A low-frequency diagonal cross-stream travelling wave first reported by Malm et al. (J. Fluid Mech. 699:320–351, 2012), has been clearly identified in the spatial modes of the stream-wise velocity components and the pressure, associated with the narrow band frequency of St¿[0.083,0.01] . This movement is caused by the geometrical expansion of the diffuser in the cross-stream direction. A second low-frequency trait has been identified associated with the persisting secondary flows and acting as a back and forth global accelerating-decelerating motion located on the straight area of the diffuser, with associated frequencies of St<0.005 . The smallest frequency observed in this work has been St=0.0013 . This low-frequency observed in the Stanford diffuser points out the need for longer simulations in order to obtain further turbulent statistics.
The research leading to this work has been partially funded by the European Project NextSim which has received funding from the European High-Performance Computing Joint Undertaking (JU) under grant agreement No 956104 and co-founded by the Spanish Agencia Estatal de Investigacion (AEI) under grant agreement PCI2021-121962. Benet Eiximeno also acknowledges the financial support by the Ministerio de Economía y Competitividad, Secretaría de Estado de Investigación, Desarrollo e Innovación, Spain (Refs: PID2020-116937RB-C21 and PID2020-116937RB-C22). Oriol Lehmkuhl has been partially supported by a Ramon y Cajal postdoctoral contract (Ref: RYC2018-025949-I). He also acknowledges the support of the European Project HiFi-TURB which has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 814837. We also acknowledge the Barcelona Supercomputing Center for awarding us access to the MareNostrum IV machine based in Barcelona, Spain. The authors acknowledge the support of Departament de Recerca i Universitats de la Generalitat de Catalunya to the Research Group Large-scale Computational Fluid Dynamics (Code: 2021 SGR 00902).
Peer Reviewed
Postprint (published version)
18 p.
eng
Springer
Attribution 4.0 International
http://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Física::Física de fluids
Turbulència
Data sets
Numerical analysis
Dinàmica de fluids computacional
DNS
POD
DMD
Separation
Confined flow
High-fidelity dataset
Turbulència
Conjunts de dades
Anàlisi numèrica
Dinàmica de fluids computacional
Self-induced large-scale motions in a three-dimensional diffuser
Article
https://link.springer.com/article/10.1007/s10494-023-00483-6
info:eu-repo/grantAgreement/EC/H2020/956104/EU/CODA: Next generation of industrial aerodynamic simulation code/NextSim
info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PID2020-116937RB-C22/ES/TOWARDS REAL-TIME ACTUATION STRATEGIES FOR FLOW CONTROL AND NOISE REDUCTION IN AIRCRAFTS./
info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PID2020-116937RB-C21/ES/ALGORITMOS DE INTELIGENCIA ARTIFICIAL Y COMPUTACION DE ALTAS PRESTACIONES PARA MODELADO DE TURBULENCIA, CONTROL DE FLUJO Y AEROACUSTICA./
info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PCI2021-121962/ES/NEXT GENERATION OF INDUSTRIAL AERODYNAMIC SIMULATION CODE/
info:eu-repo/grantAgreement/EC/H2020/814837/EU/HIGH-FIDELITY LES%2FDNS DATA FOR INNOVATIVE TURBULENCE MODELS/HIFI-TURB
37004053
Miro, A.; Eiximeno, B.; Rodriguez, I.; Lehmkuhl , O.
Flow turbulence and combustion
1
18
eprints
10.13039/501100000780
European Commission
10.13039/501100011033
Agencia Estatal de Investigación
10.13039/501100011033
Agencia Estatal de Investigación
10.13039/501100011033
Agencia Estatal de Investigación
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/1170192020-10-11T04:15:39Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Barcons, Jordi
Avila, Matias
Folch, Arnau
Barcelona Supercomputing Center
2018-05-08T13:21:13Z
2018-05-08T13:21:13Z
2018-02-06
Barcons, J.; Avila, M.; Folch, A. A wind field downscaling strategy based on domain segmentation and transfer functions. "Wind Energy", 6 Febrer 2018, vol. 21, núm. 6, p. 409-425.
1095-4244
http://hdl.handle.net/2117/117019
10.1002/we.2169
This paper presents a novel methodology for mesoscale‐to‐microscale downscaling of near‐surface wind fields. The model chain consists on the Weather Research and Forecast mesoscale model and the Alya‐CFDWind microscale model (assuming neutral stability). The downscaling methodology combines precomputed microscale simulations with a mesoscale forecast using a domain segmentation technique and transfer functions. As a result, the downscaled wind field preserves the mesoscale pattern but, at the same time, incorporates local mesoscale subgrid terrain effects, particularly at valleys and channelling zones. The methodology has been validated over a 9‐month period on a very complex terrain site instrumented with a dense observational network of meteorological masts. With respect to mesoscale results, the global skills of the downscaled wind at masts improve for wind direction and remain similar for wind velocity. However, a substantial improvement occurs under stable and neutral conditions and for high wind velocity regimes.
This work has been partially funded by the High Performance Computing for Energy (HPC4E) project (call H2020-EUB-2015, Topic: EUB-2-2015, type of action RIA, Grant Agreement number 689772) and the SEDAR ("Simulación eólica de alta resolución") project. It has also been partially supported by the Energy-oriented Centre of Excellence (EoCoE) (Grant Agreement number 676629, funded within the H2020 framework of the
EuropeanUnion). J.B. is grateful to a PhD fellowship from the IndustrialDoctorates Plan of the Government of Catalonia (Ref. eco/2497/2013). We also thank Daniel Paredes and Luis Prieto from Iberdrola Renovables S.A. for providing us access to met masts data for validation.
Peer Reviewed
Postprint (published version)
17 p.
eng
Wiley
Attribution-NonCommercial-NoDerivs 4.0 Spain
http://creativecommons.org/licenses/by-nc-nd/4.0/es/
Open Access
Àrees temàtiques de la UPC::Energies
Wind energy
Complex terrain
Downscaling
High-resolution
Near-surface winds
Transfer functions
Wind forecast
Energia eòlica
A wind field downscaling strategy based on domain segmentation and transfer functions
Article
https://onlinelibrary.wiley.com/doi/full/10.1002/we.2169
info:eu-repo/grantAgreement/EC/H2020/689772/EU/HPC for Energy/HPC4E
info:eu-repo/grantAgreement/EC/H2020/676629/EU/Energy oriented Centre of Excellence for computer applications/EoCoE
Wind Energy
21
6
409
425
eprints
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3692252022-06-28T14:00:22Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Núñez, Jorge
Catalán, Patricio A.
Valle, Carlos
Zamora, Natalia
Valderrama, Alvaro
Barcelona Supercomputing Center
2022-06-28T13:53:41Z
2022-06-28T13:53:41Z
2022-06
Núñez, J. [et al.]. Discriminating the occurrence of inundation in tsunami early warning with one-dimensional convolutional neural networks. "Scientific Reports", Juny 2022, vol. 12, 10321.
2045-2322
http://hdl.handle.net/2117/369225
10.1038/s41598-022-13788-9
Tsunamis are natural phenomena that, although occasional, can have large impacts on coastal environments and settlements, especially in terms of loss of life. An accurate, detailed and timely assessment of the hazard is essential as input for mitigation strategies both in the long term and during emergencies. This goal is compounded by the high computational cost of simulating an adequate number of scenarios to make robust assessments. To reduce this handicap, alternative methods could be used. Here, an enhanced method for estimating tsunami time series using a one-dimensional convolutional neural network model (1D CNN) is considered. While the use of deep learning for this problem is not new, most of existing research has focused on assessing the capability of a network to reproduce inundation metrics extrema. However, for the context of Tsunami Early Warning, it is equally relevant to assess whether the networks can accurately predict whether inundation would occur or not, and its time series if it does. Hence, a set of 6776 scenarios with magnitudes in the range Mw 8.0–9.2 were used to design several 1D CNN models at two bays that have different hydrodynamic behavior, that would use as input inexpensive low-resolution numerical modeling of tsunami propagation to predict inundation time series at pinpoint locations. In addition, different configuration parameters were also analyzed to outline a methodology for model testing and design, that could be applied elsewhere. The results show that the network models are capable of reproducing inundation time series well, either for small or large flow depths, but also when no inundation was forecast, with minimal instances of false alarms or missed alarms. To further assess the performance, the model was tested with two past tsunamis and compared with actual inundation metrics. The results obtained are promising, and the proposed model could become a reliable alternative for the calculation of tsunami intensity measures in a faster than real time manner. This could complement existing early warning system, by means of an approximate and fast procedure that could allow simulating a larger number of scenarios within the always restricting time frame of tsunami emergencies.
Tide gauge data were obtained from the Sea Level Station Monitoring Facility of the Intergovernmental Oceanographic Commission (http://www.ioc-sealevelmonitoring.org/list.php). The coarser bathymetric and topographic data from the General Bathymetric Chart of the Ocean (https://www.gebco.net/data_and_products/gridded_bathymetry_data/). The authors acknowledge SHOA for providing nautical charts and coastal zone plans used to generate high resolution topo-bathymetric grids for research purposes. We are deeply grateful with A. Gubler that prepared a first version of the high resolution bathymetry grids. The authors acknowledge the computer resources at CTE-POWER (https://www.bsc.es/supportkc/docs/CTE-POWER/overview) and the technical support provided by BSC. We are greatly thankful the EDANYA Group at Málaga University for sharing the Tsunami-HySEA code. Most figures were generated with Python91,92,93 and Global Mapping Tools94. JN deeply thanks support of Mitiga Solutions during his secondment. PAC would like to thank funding by ANID, Chile Grants FONDEF ID19I10048, Centro de Investigación para la Gestión Integrada del Riesgo de Desastres (CIGIDEN) ANID/FONDAP/15110017, and Centro Científico Tecnológico de Valparaíso, ANID PIA/APOYO AFB180002. NZ has received funding from the Marie Skłodowska-Curie grant agreement H2020-MSCA-COFUND-2016-75443.
Peer Reviewed
Postprint (published version)
20 p.
eng
Nature Research
Attribution 4.0 International
http://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Informàtica::Aplicacions de la informàtica::Aplicacions informàtiques a la física i l‘enginyeria
Tsunamis
Neural networks (Computer science)
Floods
Tsunami
Neural networks
Mathematical model
Simulació per ordinador
Discriminating the occurrence of inundation in tsunami early warning with one-dimensional convolutional neural networks
Article
https://www.nature.com/articles/s41598-022-13788-9
10321
Scientific Reports
12
eprints
oai:upcommons.upc.edu:2117/3665392022-05-01T15:05:00Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Meta, Irene
Cucchietti, Fernando
Navarro Mateu, Diego
Graells Garrido, Eduardo
Guallart, Vicente
Barcelona Supercomputing Center
2022-04-28T15:09:33Z
2022-04-28T15:09:33Z
2022
Meta, I. [et al.]. A physiology-inspired framework for holistic city simulations. "Cities", 2022, vol. 126, 103553.
0264-2751
http://hdl.handle.net/2117/366539
10.1016/j.cities.2021.103553
Life, services and activities within cities have commonly been studied by separate disciplines, each one independent from the others. One such approach is the computer simulation, which enables in-depth modelling and cost-effective evaluation of city phenomena. However, the adoption of integrated city simulations faces several barriers, such as managerial, social, and technical, despite its potential to support city planning and policymaking. This paper introduces the City Physiology: a new conceptual framework to facilitate the integration of city layers when designing holistic simulators. The physiology is introduced and applied through a process of three steps. Firstly, a literature review is offered in order to study the terminology and the progress already made towards integrated modelling of different urban systems. Secondly, interactions between urban systems are extracted from the approaches studied before. Finally, the pipeline to carry out the integration strategy is described. In addition to providing a conceptual tool for holistic simulations, the framework enables the discovery of new research lines generated by previously unseen connections between city layers. Being an open framework, available to all researchers to use and broaden, the authors of this paper envisage that it will be a valuable resource in establishing an exact science of cities.
Peer Reviewed
Postprint (published version)
14 p.
eng
Elsevier
Attribution 3.0 Spain
Attribution 4.0 International (CC BY 4.0)
http://creativecommons.org/licenses/by/3.0/es/
https://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Informàtica::Aplicacions de la informàtica::Aplicacions informàtiques a la física i l‘enginyeria
Urban environment
Policymaking
Urban informatics
Integrated modelling
Holistic simulation
Simulació per ordinador
A physiology-inspired framework for holistic city simulations
Article
https://www.sciencedirect.com/science/article/pii/S0264275121004522?via%3Dihub#!
info:eu-repo/grantAgreement/EC/H2020/857191/EU/Distributed Digital Twins for industrial SMEs: a big-data platform/IoTwins
103553
Cities
126
eprints
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3865192023-04-23T15:17:56Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Birkenmeier, Gregor
Solano, Emilia R
Carvalho, Ivo
Hillesheim, J C
Delabie, E
Gallart Escolà, Dani
Mantsinen, Mervi
Barcelona Supercomputing Center
2023-04-21T12:03:37Z
2023-04-21T12:03:37Z
2023
Birkenmeier, G. [et al.]. The role of isotope mass and transport for H-mode access in tritium containing plasmas at JET with ITER-like wall. "Plasma Physics and Controlled Fusion", 2023, vol. 65, núm. 5, 054001.
0741-3335
1361-6587
http://hdl.handle.net/2117/386519
10.1088/1361-6587/acc423
The required heating power, , to access the high confinement regime (H-mode) in tritium containing plasmas is investigated in JET with ITER-like wall at a toroidal magnetic field of T and a plasma current of MA. , also referred to as the L-H power threshold, is determined in plasmas of pure tritium as well as mixtures of hydrogen with tritium (H-T) and mixtures of deuterium with tritium (D-T), and is compared to the L-H power threshold in plasmas of pure hydrogen and pure deuterium. It is found that, for otherwise constant parameters, is not the same in plasmas with the same effective isotope mass, , when they differ in their isotope composition. Thus, is not sufficient to describe the isotope effect of in a consistent manner for all considered isotopes and isotope mixtures. The electron temperature profiles measured at the L-H transition in the outer half of the radius are very similar for all isotopes and isotope mixtures, despite the fact that the L-H power threshold varies by a factor of about six. This finding, together with the observation of an offset linear relation between the L-H power threshold, , and an effective heat diffusivity, , indicates that the composition-dependent heat transport in the low confinement mode (L-mode) determines, how much power is needed to reach the necessary electron temperatures at the edge, and hence .
This work has been carried out within the framework of the EUROfusion Consortium, funded by the European Union via the Euratom Research and Training Programme (Grant Agreement No. 101052200—EUROfusion). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Commission. Neither the European Union nor the European Commission can be held responsible for them. G Birkenmeier received funding from the Helmholtz Association under Grant No. VH-NG-1350
Peer Reviewed
Postprint (published version)
"Article signat per 50 autors/es: G Birkenmeier, E R Solano, I S Carvalho, J C Hillesheim, E Delabie, E Lerche, D Taylor, D Gallart, M J Mantsinen, C Silva, C Angioni, F Ryter, P Carvalho, M Fontana, E Pawelec, S A Silburn, P Sirén, S Aleiferis, J Bernardo, A Boboc, D Douai, P Puglia, P Jacquet, E Litherland-Smith, I Jepu, D Kos, H J Sun, A Shaw, D King, B Viola, R Henriques, K K Kirov, M Baruzzo, J Garcia, A Hakola, A Huber, E Joffrin, D Keeling, A Kappatou, M Lennholm, P Lomas, E de la Luna, C F Maggi, J Mailloux, M Maslov, F G Rimini, N Vianello, G Verdoolaege, H Weisen, M Wischmeier and JET Contributors"
eng
IOP Publishing
Attribution 4.0 International
http://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Física
Nuclear fusion
L-H transition
D-T plasma operation
Isotope effects
Tranasport
Isotope mixtures
Tritium plasmas
Simulació per ordinador
The role of isotope mass and transport for H-mode access in tritium containing plasmas at JET with ITER-like wall
Article
https://iopscience.iop.org/article/10.1088/1361-6587/acc423
054001
Plasma Physics and Controlled Fusion
65
5
eprints
oai:upcommons.upc.edu:2117/1086822020-07-23T23:27:48Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Rubio-Campillo, Xavier
Coto-Sarmiento, María
Pérez-Gonzalez, Jordi
Remesal, José
Barcelona Supercomputing Center
2017-10-13T10:52:38Z
2017-10-13T10:52:38Z
2017-09-20
Rubio-Campillo, X. [et al.]. Bayesian analysis and free market trade within the Roman Empire. "Antiquity", 20 Setembre 2017, vol. 91, núm. 359, p. 1241-1252.
0003-598X
http://hdl.handle.net/2117/108682
10.15184/aqy.2017.131
The trade networks of the Roman Empire are among the most intensively researched large-scale market systems in antiquity, yet there is no consensus on the economic structure behind this vast network. The difficulty arises from data fragmentation and the lack of formal analytical methods. Here, the authors present a Bayesian analysis quantifying the extent to which four previously proposed hypotheses match the evidence for the market system in Roman olive oil. Results suggest that the size of economic agents involved in this network followed a power-law distribution, strongly indicating the presence of free market structures supplying olive oil to Rome. This new analysis offers an important tool to researchers exploring the impact of trade on the dynamics of past societies.
XRC and MCS were funded by the European Research Council Advanced Grant EPNet (340828). We would like to thank the two anonymous reviewers for their comments on previous versions of the manuscript.
We would also like to thank Enrico Crema, Albert Díaz-Guilera, Luce Prignano, Ignacio Morer, Jean-Marc Montanier, Simon Carrignon, Joan Rodríguez, Víctor Revilla, Maria Yubero, Jonàs Alcaina, Pau Valdés, Alessandra Pecci and Tom Brughmans for advice on the analysis, access to unpublished data and productive discussions on the methods and results of this work.
The dataset is distributed under the terms of a Creative Commons Attribution-Share Alike 4.0 International Licence. The source code of the model is licensed under a GNU General Public Licence; both can be downloaded from https://github.com/xrubio/bayesRome (accessed 9 June 2017).
Peer Reviewed
Postprint (published version)
12 p.
eng
Cambridge University Press
Attribution-NonCommercial-NoDerivs 3.0 Spain
http://creativecommons.org/licenses/by-nc-nd/3.0/es/
Open Access
Àrees temàtiques de la UPC::Desenvolupament humà i sostenible
Roman Empire
Bayesian analysis
Market analyses and perspectives
Roman Empire
Bayesian analysis
Olive oil
Trade
Model selection
Roma--Història--30 aC-476 dC, Imperi
Estadística bayesiana
Mercat--Anàlisi
Bayesian analysis and free market trade within the Roman Empire
Article
http://www.research.ed.ac.uk/portal/en/publications/bayesian-analysis-and-free-market-trade-within-the-roman-empire(d664024d-7e97-439d-b2ec-36242de4004c).html
info:eu-repo/grantAgreement/EC/FP7/340828/EU/Production and distribution of food during the Roman Empire: Economics and political dynamics./EPNET
Antiquity
91
359
1241
1252
eprints
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3282412020-10-11T04:23:27Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Oliveira, Micael J.T.
Papior, Nick
Pouillon, Yann
Blum, Volker
Artacho, Emilio
Caliste, Damien
Corsetti, Fabiano
Gironcoli, Stefano, de
Elena, Alin M.
García, Alberto
García-Suárez, Víctor M.
Genovese, Luigi
Huhn, William P.
Huhs, Georg
Kokott, Sebastian
Küçükbenli, Emine
Larsen, Ask H.
Lazzaro, Alfio
Lebedeva, Irina V.
Li, Yingzhou
López-Durán, David
López-Tarifa, Pablo
Lüders, Martin
Marques, Miguel A. L.
Minar, Jan
Mohr, Stephan
Mostofi, Arash A.
O’Cais, Alan
Payne, Mike C.
Ruh, Thomas
Smith, Daniel G.A.
Soler, José M.
Strubbe, David A.
Tancogne-Dejean, Nicolas
Tildesley, Dominic
Torrent, Marc
Wen-zhe Yu, Victor
Barcelona Supercomputing Center
2020-08-28T15:19:30Z
2020-08-28T15:19:30Z
2020-07-13
Oliveira, M.J.T. [et al.]. The CECAM electronic structure library and the modular software development paradigm. "The Journal of Chemical Physics", 13 Juliol 2020, vol. 153, núm. 2, 024117.
0021-9606
http://hdl.handle.net/2117/328241
10.1063/5.0012901
First-principles electronic structure calculations are now accessible to a very large community of users across many disciplines, thanks to many successful software packages, some of which are described in this special issue. The traditional coding paradigm for such packages is monolithic, i.e., regardless of how modular its internal structure may be, the code is built independently from others, essentially from the compiler up, possibly with the exception of linear-algebra and message-passing libraries. This model has endured and been quite successful for decades. The successful evolution of the electronic structure methodology itself, however, has resulted in an increasing complexity and an ever longer list of features expected within all software packages, which implies a growing amount of replication between different packages, not only in the initial coding but, more importantly, every time a code needs to be re-engineered to adapt to the evolution of computer hardware architecture. The Electronic Structure Library (ESL) was initiated by CECAM (the European Centre for Atomic and Molecular Calculations) to catalyze a paradigm shift away from the monolithic model and promote modularization, with the ambition to extract common tasks from electronic structure codes and redesign them as open-source libraries available to everybody. Such libraries include “heavy-duty” ones that have the potential for a high degree of parallelization and adaptation to novel hardware within them, thereby separating the sophisticated computer science aspects of performance optimization and re-engineering from the computational science done by, e.g., physicists and chemists when implementing new ideas. We envisage that this modular paradigm will improve overall coding efficiency and enable specialists (whether they be computer scientists or computational scientists) to use their skills more effectively and will lead to a more dynamic evolution of software in the community as well as lower barriers to entry for new developers. The model comes with new challenges, though. The building and compilation of a code based on many interdependent libraries (and their versions) is a much more complex task than that of a code delivered in a single self-contained package. Here, we describe the state of the ESL, the different libraries it now contains, the short- and mid-term plans for further libraries, and the way the new challenges are faced. The ESL is a community initiative into which several pre-existing codes and their developers have contributed with their software and efforts, from which several codes are already benefiting, and which remains open to the community
The authors would like to thank CECAM for launching and pushing the ESL, as well as hosting part of its infrastructure, and partly funding the extended workshops where most of the coding was done, both in the Lausanne headquarters and in the Dublin, Trieste, and Zaragoza nodes. Within CECAM, the authors particularly thank Sara Bonella, Bogdan Nichita, and Ignacio Pagonabarraga. The authors also acknowledge all the people who have supported and contributed to the ESL in different ways, including Luis Agapito, Xavier Andrade, Balint Aradi, Emanuele Bosoni, Lori A. Burns, Christian Carbogno, Ivan Carnimeo, Abel Carreras Conill, Alberto Castro, Michele Ceriotti, Anoop Chandran, Wibe de Jong, Pietro Delugas, Thierry Deutsch, Hubert Ebert, Aleksandr Fonari, Luca Ghiringhelli, Paolo Giannozzi, Matteo Giantomassi, Judit Gimenez, Ivan Girotto, Xavier Gonze, Benjamin Hourahine, Jürg Hutter, Thomas Keal, Jan Kloppenburg, Hyungjun Lee, Liang Liang, Lin Lin, Jianfeng Lu, Nicola Marzari, Donal MacKernan, Layla Martin-Samos, Paolo Medeiros, Fawzi Mohamed, Jens Jørgen Mortensen, Sebastian Ohlmann, David O’Regan, Charles Patterson, Etienne Plésiat, Markus Rampp, Laura Ratcliff, Stefano Sanvito, Paul Saxe, Matthias Scheffler, Didier Sebilleau, Søren Smidstrup, James Spencer, Atsushi Togo, Joost Vandevondele, Matthieu Verstraete, and Brian Wylie.
The authors would also like to thank the Psi-k network for having partially funded several of the ESL workshops. A.O., E.A., D.L.-D., S.G., E.K., A.A.M., and M.C.P. received funding from the European Union’s Horizon 2020 research and innovation program under Grant Agreement No. 676531 (Centre of Excellence project E-CAM). The same project has partly funded the extended software development workshops in which most of the ESL coding effort has happened. A.G., S.M., and E.A. acknowledge support from the European Union’s Horizon 2020 research and innovation program under Grant Agreement No. 824143 (Centre of Excellence project MaX). M.A.L.M. acknowledges partial support from the DFG through Project No. MA-6786/1. D.G.A.S. was supported by the U.S. National Science Foundation (NSF) (Grant No. ACI-1547580). M.C.P. acknowledges support from the EPSRC under Grant No. EP/P034616/1. A.A.M. acknowledges support from the Thomas Young Centre under Grant No. TYC-101, the Wannier Developers Group, and all of the authors and contributors of the wannier90 code (see Ref. 115 for a complete list). A.M.E. acknowledges support from CoSeC, the Computational Science Centre for Research Communities, through CCP5: The Computer Simulation of Condensed Phases (EPSRC Grant Nos. EP/M022617/1 and EP/P022308/1). A.G. and J.M.S. acknowledge Spain’s Ministry of Science (Grant No. PGC2018-096955-B-C42). E.A., A.G., and J.M.S. acknowledge Spain’s Ministry of Science (Grant No. FIS2015-64886-C5). Y.P., D.L.-D., and E.A. acknowledge support from the Spanish MINECO and EU Structural Investment Funds (Grant No. RTC-2016-5681-7). M.L. acknowledges support from the EPRSC under Grant No. EP/M022668/1. M.L., M.J.T.O., and Y.P. acknowledge support from the EU COST action (Grant No. MP1306). J.M. was supported by the European Regional Development Fund (ERDF), project CEDAMNF (Reg. No. CZ.02.1.01/0.0/0.0/15-003/0000358). V.W.-Z.Y., W.P.H., Y.L., and V.B. acknowledge support from the National Science Foundation under Award No. ACI-1450280 (the ELSI project). V.W.-Z.Y. also acknowledges a MolSSI fellowship (NSF Award No. ACI-1547580). Simune Atomistics S.L. is thanked for allowing A.H.L. and Y.P. to contribute to the ESL, as is Synopsys, Inc., for the partial availability of F.C
Peer Reviewed
Postprint (author's final draft)
27 p.
eng
AIP Publishing
Àrees temàtiques de la UPC::Informàtica::Arquitectura de computadors
Software engineering
Open source library
Computational science and engineering
Modular programming
Electronic Structure Library (ESL)
CECAM (the European Centre for Atomic and Molecular Calculations)
Open-source libraries
Modular software
Computer hardware architecture
Enginyeria de programari
The CECAM electronic structure library and the modular software development paradigm
Article
https://aip.scitation.org/doi/10.1063/5.0012901
info:eu-repo/grantAgreement/EC/H2020/824143/EU/MAterials design at the eXascale. European Centre of Excellence in materials modelling, simulations, and design/MaX
Open Access
024117
The Journal of Chemical Physics
153
2
eprints
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/849512021-06-20T03:57:39Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Bates, Alister J.
Doorly, Denis J.
Cetto, Raul
Calmet, Hadrien
Gambaruto, Alberto
Tolley, Neil
Houzeaux, Guillaume
Schroter, Robert
Barcelona Supercomputing Center
2016-03-31T11:32:59Z
2016-03-31T11:32:59Z
2015-01-06
Bates, Alister J. [et al.]. Dynamics of Airflow in a Short Inhalation. "Interface", 06 Gener 2015, vol. 12, núm. 102.
1742-5662
http://hdl.handle.net/2117/84951
10.1098/rsif.2014.0880
25551147
During a rapid inhalation, such as a sniff, the flowin the airways accelerates and decays quickly. The consequences for flow development and convective transport of an inhaled gas were investigated in a subject geometry extending from the nose to the bronchi. The progress of flow transition and the advance of an inhaled non-absorbed gas were determined using highly resolved simulations of a sniff 0.5 s long, 1 l s21 peak flow, 364 ml inhaled volume. In the nose, the distribution of airflow evolved through three phases: (i) an initial transient of about 50 ms, roughly the filling time for a nasal volume, (ii) quasi-equilibrium over themajority of the inhalation, and (iii) a terminating phase. Flow transition commenced in the supraglottic region within 20 ms, resulting in largeamplitude fluctuations persisting throughout the inhalation; in the nose, fluctuations that arose nearer peak flow were of much reduced intensity and diminished in the flow decay phase. Measures of gas concentration showed non-uniform build-up and wash-out of the inhaled gas in the nose. At the carina, the form of the temporal concentration profile reflected both shear dispersion and airway filling defects owing to recirculation regions.
This research was supported by EPSRC Doctoral
Training Award EP/P505550/1.
Electronic supplementary material is available
at http://dx.doi.org/10.1098/rsif.2014.0880 or
via http://rsif.royalsocietypublishing.org.
Peer Reviewed
Postprint (published version)
15 p.
eng
The Royal Society
Attribution 4.0 International License
The Authors. Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited.
https://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Enginyeria biomèdica
Biomechanics
Transitional flow
Inspiratory flow
Respiratory tract
Airways
CFD
Internal flow
Transitional flow
Gasos--Flux
Dynamics of Airflow in a Short Inhalation
Article
http://rsif.royalsocietypublishing.org/content/12/102/20140880.article-info
Interface
12
102
eprints
oai:upcommons.upc.edu:2117/3342462022-11-01T01:26:46Zcom_2117_79677com_2117_28579com_2117_28577com_2117_98851com_2117_28581com_2117_3989com_2117_80515com_2117_23714com_2117_28578com_2117_15797col_2117_79695col_2117_103655col_2117_3990col_2117_80523col_2117_3055openAccess
Rodríguez Pérez, Ivette María
Lehmkuhl Barba, Oriol
Soria Guerrero, Manel
Universitat Politècnica de Catalunya. Departament de Màquines i Motors Tèrmics
Universitat Politècnica de Catalunya. Departament de Física
Barcelona Supercomputing Center
Universitat Politècnica de Catalunya. TUAREG - Turbulence and Aerodynamics in Mechanical and Aerospace Engineering Research Group
2020-12-11T08:56:05Z
2022-11-01T01:26:46Z
2021-01
Rodriguez, I.; Lehmkuhl, O.; Soria, M. On the effects of the free-stream turbulence on the heat transfer from a sphere. "International journal of heat and mass transfer", 2021, vol. 164, p. 120579/1-120579/18.
0017-9310
http://hdl.handle.net/2117/334246
10.1016/j.ijheatmasstransfer.2020.120579
Free-stream turbulence is present in many engineering applications and is known to affect both bluffbody aerodynamics and heat transfer. In this work, its effects on the heat transfer and the near wake behind a sphere are studied. To do this, direct and large-eddy simulations of the flow at the moderate Reynolds numbers of Re = 1000 and Re = 1e4 , with levels of incoming turbulence up to 10% and a length scale of O(D ) ,D being the sphere diameter, are performed. At the Reynolds numbers under consideration, significant changes are observed. Incoming turbulence delays the separation of the laminar boundary layer from the sphere, while at the same time the drag coefficient and the Nusselt number are increased. The incoming level of turbulence also increases the momentum transfer from the surrounding fluid and energises the separated shear-layer. As a consequence, there is a shrinking of the recirculation zone which intensifies the heat transfer from the sphere and thus, the Nusselt number and its fluctuations, especially in the rear zone of the sphere. It is shown that free-stream turbulence increases the turbulent heat flux in the wake, with a larger entrainment of colder fluid from the surroundings, thus producing a faster decay of the temperature at larger levels of turbulence intensity.
This work has been partially financially supported by the Minis- terio de Economía y Competitividad, Secretaría de Estado de Investigación, Desarrollo e Innovación, Spain (refs. ESP2016-79612-C3- 2-R & TRA2017-88508-R). We also acknowledge Red Española de Surpercomputación (RES) for awarding us access to the MareNos- trum IV machine based in Barcelona, Spain (Ref. FI-2017-2-0012 & FI-2017-3-0018)
Postprint (author's final draft)
eng
Attribution-NonCommercial-NoDerivs 3.0 Spain
http://creativecommons.org/licenses/by-nc-nd/3.0/es/
Open Access
Àrees temàtiques de la UPC::Física::Termodinàmica
Turbulence--Computer simulation
Nusselt number
Heat -- Transmission
Free-stream turbulence
Heat transfer
Sphere
Nusselt number
Turbulent thermal wake
Turbulència -- Simulació per ordinador
Calor -- Transmissió
Nusselt, Nombre de
On the effects of the free-stream turbulence on the heat transfer from a sphere
Article
https://www.sciencedirect.com/science/article/pii/S0017931020335158?dgcid=rss_sd_all
info:eu-repo/grantAgreement/MINECO/1PE/ESP2016-79612-C3-2-R
29870493
Rodriguez, I.; Lehmkuhl, O.; Soria, M.
International journal of heat and mass transfer
164
120579/1
120579/18
eprints
oai:upcommons.upc.edu:2117/901422020-10-11T04:31:12Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
de la Cruz, Raúl
Folch, Arnau
Farré, Pau
Cabezas, Javier
Navarro, Nacho
Cela, José M.
Barcelona Supercomputing Center
2016-09-22T13:12:58Z
2018-12-01T01:30:48Z
2016-12
de la Cruz, Raúl [et al.]. Optimization of atmospheric transport models on HPC platforms. "Computers & Geosciences", Desembre 2016, vol. 97, p. 30-39.
0098-3004
http://hdl.handle.net/2117/90142
10.1016/j.cageo.2016.08.019
The performance and scalability of atmospheric transport models on high performance computing environments is often far from optimal for multiple reasons including, for example, sequential input and output, synchronous communications, work unbalance, memory access latency or lack of task overlapping. We investigate how different software optimizations and porting to non general-purpose hardware architectures improve code scalability and execution times considering, as an example, the FALL3D volcanic ash transport model. To this purpose, we implement the FALL3D model equations in the WARIS framework, a software designed from scratch to solve in a parallel and efficient way different geoscience problems on a wide variety of architectures. In addition, we consider further improvements in WARIS such as hybrid MPI-OMP parallelization, spatial blocking, auto-tuning and thread affinity. Considering all these aspects together, the FALL3D execution times for a realistic test case running on general-purpose cluster architectures (Intel Sandy Bridge) decrease by a factor between 7 and 40 depending on the grid resolution. Finally, we port the application to Intel Xeon Phi (MIC) and NVIDIA GPUs (CUDA) accelerator-based architectures and compare performance, cost and power consumption on all the architectures. Implications on time-constrained operational model configurations are discussed.
We thank M.S. Osores from the Argentinean National Scientific and Technical Research Council (CONICET) for providing hourly
column heights for the Cordón Caulle eruption simulation and the constructive
comments from two anonymous reviewers. This work was supported by NVIDIA through the UPC/BSC GPU Center of Excellence,
and the Spanish Ministry of Science and Technology through the TIN2012-34557 project. Finally, we dedicate this work to our colleague and co-author Nacho Navarro, who sadly passed away during the reviewing process.
Peer Reviewed
Postprint (author's final draft)
10 p.
eng
Elsevier
Attribution-NonCommercial-NoDerivs 4.0 International License
https://creativecommons.org/licenses/by-nc-nd/4.0/
Open Access
Àrees temàtiques de la UPC::Enginyeria biomèdica::Impacte ambiental
Atmosphere--Measurement
Weather Prediction Research Programmes
Parallel programming (Computer science)
HPC platforms
Atmospheric transport models
FALL3D model
Programació en paral·lel (Informàtica)
Clima--Observacions
Atmosfera -- Mesurament
Optimization of atmospheric transport models on HPC platforms
Article
http://www.sciencedirect.com/science/article/pii/S0098300416303077
info:eu-repo/grantAgreement/MINECO/1PE/TIN2012-34557
Computers & Geosciences
97
30
39
eprints
oai:upcommons.upc.edu:2117/884752020-07-23T23:27:49Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Montanier, Jean-Marc
Carrignon, Simon
Bredeche, Nicolas
Barcelona Supercomputing Center
2016-07-04T09:18:45Z
2016-07-04T09:18:45Z
2016-07-04
Montanier, Jean-Marc; Carrignon, Simon; Bredeche, Nicolas. Behavioural Specialisation in Embodied Evolutionary Robotics: Why so Difficult?. "", 04 Juliol 2016, vol. 3, núm. 38.
2296-9144
http://hdl.handle.net/2117/88475
10.3389/frobt.2016.00038
Embodied evolutionary robotics is an on-line distributed learning method used in collective robotics where robots are facing open environments. This paper focuses on learning behavioral specialization, as defined by robots being able to demonstrate different kind of behaviors at the same time (e.g., division of labor). Using a foraging task with two resources available in limited quantities, we show that behavioral specialization is unlikely to evolve in the general case, unless very specific conditions are met regarding interactions between robots (a very sparse communication network is required) and the expected outcome of specialization (specialization into groups of similar sizes is easier to achieve).
We also show that the population size (the larger the better) as well as the selection scheme used (favoring exploration over exploitation) both play important – though not always mandatory – roles. This research sheds light on why existing embodied evolution algorithms are limited with respect to learning efficient division of labor in the general case, i.e., where it is not possible to guess before deployment if behavioral specialization is required or not, and gives directions to overcome current limitations.
This work is supported by the European Unions Horizon 2020 research and innovation programme under grant agreement No 640891, and the ERC Advanced Grant EPNet (340828). Part of the experiments presented in this paper were carried out using the Grid’5000 experimental testbed, being developed under the INRIA ALADDIN development action with support from CNRS, RENATER, and several Universities as well as other funding bodies (see https://www.grid5000.fr). The other parts of the simulations have been done in the supercomputer MareNostrum at Barcelona Supercomputing Center – Centro Nacional de Supercomputacion (The Spanish National Supercomputing Center).
Peer Reviewed
Postprint (published version)
11 p.
eng
Frontiers Media
Attribution 4.0 International License
http://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Enginyeria electrònica
Evolutionary robotics--Computer simulation
Behavioral modeling
Algorithms--Data processing
Embodied evolution
Evolutionary robotics
Behavioral specialization
Division of labor
Distributed online learning
Collective behavior
Robots--Programació
Robòtica evolutiva
Behavioural Specialisation in Embodied Evolutionary Robotics: Why so Difficult?
Article
http://journal.frontiersin.org/article/10.3389/frobt.2016.00038/full
info:eu-repo/grantAgreement/EC/H2020/640891/EU/Deferred Restructuring of Experience in Autonomous Machines/DREAM
info:eu-repo/grantAgreement/EC/FP7/340828/EU/Production and distribution of food during the Roman Empire: Economics and political dynamics./EPNET
3
38
eprints
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/1206602020-07-23T23:27:49Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Voitsekhovitch, I.
Hatzky, R.
Coster, D.
Imbeaux, F.
McDonald, D.C.
Fehér, T.B.
Kang, K.S.
Leggate, H.
Martone, M.
Mochalskyy, S.
Sáez, Xavier
Ribeiro, T.
Tran, T.-M-
Gutierrez-Milla, A.
Aniel, T.
Figat, D.
Fleury, L.
Hoenen, O.
Hollocombe, J.
Kaljun, D.
Manduchi, G.
Owsiak, M.
Pais, V.
Palak, B.
Plociennik, M.
Signoret, J.
Vouland, C.
Yadykin, D.
Robin, F.
Iannone, F.
Bracco, G.
David, J.
Maslennikov, A.
Noé, J.
Rossi, E.
Kamendje, R.
Heuraux, S.
Hölzl, M.
Pinches, S.D.
da Silva, F.
Tskhakaya, D.
Barcelona Supercomputing Center
2018-08-29T14:24:30Z
2018-08-29T14:24:30Z
2018-02-21
Voitsekhovitch, I. [et al.]. Recent EUROfusion Achievements in Support of Computationally Demanding Multiscale Fusion Physics Simulations and Integrated Modeling. "Fusion Science and Technology", 21 Febrer 2018.
1536-1055
http://hdl.handle.net/2117/120660
10.1080/15361055.2018.1424483
Integrated modeling (IM) of present experiments and future tokamak reactors requires the provision of computational resources and numerical tools capable of simulating multiscale spatial phenomena as well as fast transient events and relatively slow plasma evolution within a reasonably short computational time. Recent progress in the implementation of the new computational resources for fusion applications in Europe based on modern supercomputer technologies (supercomputer MARCONI-FUSION), in the optimization and speedup of the EU fusion-related first-principle codes, and in the development of a basis for physics codes/modules integration into a centrally maintained suite of IM tools achieved within the EUROfusion Consortium is presented. Physics phenomena that can now be reasonably modelled in various areas (core turbulence and magnetic reconnection, edge and scrape-off layer physics, radio-frequency heating and current drive, magnetohydrodynamic model, reflectometry simulations) following successful code optimizations and parallelization are briefly described. Development activities in support to IM are summarized. They include support to (1) the local deployment of the IM infrastructure and access to experimental data at various host sites, (2) the management of releases for sophisticated IM workflows involving a large number of components, and (3) the performance optimization of complex IM workflows.
This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014 to 2018 under grant agreement 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission or ITER.
Peer Reviewed
Postprint (published version)
12 p.
eng
American Nuclear Society
Attribution-NonCommercial-NoDerivs 3.0 Spain
http://creativecommons.org/licenses/by-nc-nd/3.0/es/
Open Access
Àrees temàtiques de la UPC::Física
Nuclear fusion
High-performance computer
Infrastructure for integrated modeling
Code optimization and parallelization
Fusió nuclear
Recent EUROfusion Achievements in Support of Computationally Demanding Multiscale Fusion Physics Simulations and Integrated Modeling
Article
https://www.tandfonline.com/doi/full/10.1080/15361055.2018.1424483
info:eu-repo/grantAgreement/EC/H2020/633053/EU/Implementation of activities described in the Roadmap to Fusion during Horizon 2020 through a Joint programme of the members of the EUROfusion consortium/EUROfusion
Fusion Science and Technology
eprints
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3459252023-10-09T07:58:27Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Illana, Enric
Mira Martínez, Daniel
Mura, Arnaud
Barcelona Supercomputing Center
2021-05-19T14:14:18Z
2021-11-12T01:27:48Z
2020
Illana, E.; Mira, D.; Mura, A. An extended flame index partitioning for partially premixed combustion. "Combustion Theory and Modelling", 2020, vol. 25, núm. 1, p. 121-157.
1364-7830
1741-3559
http://hdl.handle.net/2117/345925
10.1080/13647830.2020.1841912
Compared to partially premixed combustion (or combustion of non-homogeneous reactants in general), fully premixed and diffusion flames represent only two asymptotic limits of combustion modes. However, the deep knowledge accumulated over the years on these two elementary and archetypal flame prototypes is such that they remain the cornerstone and reference building blocks of most combustion modelling proposals. Therefore, from a general point of view, being able to distinguish between premixed and non-premixed modes of combustion thanks to a flame index appears as a quite appealing but challenging task that still concentrates many research efforts. Indeed, the availability of such an index is not only appealing to proceed with the analysis of either experimental or computational data issued from DNS (or highly resolved LES) databases. It is also an essential ingredient to elaborate advanced flamelet-based multiregime combustion models on the basis of single regime tabulated flamelet databases. In the present study, a new definition of the premixedness index ζPF is proposed for partially premixed combustion. It is based on a weighted form of the cross-scalar dissipation rate of the mixture fraction Yξ and progress variable Yc, i.e. quantities that have been previously identified as relevant parameters to describe partially premixed combustion regimes. The relevance of the corresponding index is assessed through a detailed computational procedure that includes three successive validation subsets: counterflow flames (including premixed, rich partially-premixed, and diffusion flames), (ii) stabilised triple flames for three distinct values of the inlet mixture fraction gradient, and finally (iii) unsteady flame kernel developments in non-homogeneous mixtures of fresh reactants, which are characterised by various initial levels of the segregation rate between the fuel and oxidiser. The proposed premixedness index ζPF and its counterpart ζDF=1−ζPF are used as the weighting coefficients between tabulated premixed flamelets (TPF) and tabulated diffusion flamelets (TDF) data, which have been parameterised as functions of Yξ and Yc. It is noteworthy that, in contrast to some previous proposals of the literature, the present flame index does not require the consideration of any other quantities in addition to those already used to parameterise the flamelets databases, i.e. Yξ and Yc. The validation procedure makes use of steady and unsteady processes with a priori and a posteriori analyses. In both cases, the comparisons between the results obtained with the proposed flame partitioning and detailed chemistry (DC) computations lead to a satisfactory level of agreement and, from a general viewpoint, the level of agreement is better than the one obtained with either premixed or diffusion flamelet-based models.
Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – Project-ID 422037413 – TRR 287.
Daniel Mira acknowledges the funding received through the Spanish Ministry of Economy and Competitiveness in the frame of the CHEST project (TRA2017-89139-C2-2-R) and the ESTiMatE project from the Clean Sky 2 Joint Undertaking under the European Union's Horizon 2020 research and innovation programme under grant agreement No 821418.
Conflict of Interest: Daniel Mira acknowledges the Juan de la Cierva personal grant IJCI-2015-26686.
Peer Reviewed
Postprint (author's final draft)
36 p.
eng
Taylor and Francis
Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)
https://creativecommons.org/licenses/by-nc/4.0/
Open Access
Àrees temàtiques de la UPC::Informàtica::Aplicacions de la informàtica::Aplicacions informàtiques a la física i l‘enginyeria
Data sets
Premixed combustion
Non-premixed combustion
Partially premixed combustion
Flame index
Premixedness index
Multi-regime Flamelet Model
Combustió
An extended flame index partitioning for partially premixed combustion
Article
https://www.tandfonline.com/eprint/DNSJZXEWMKNG9MN8PHWD/full?target=10.1080/13647830.2020.1841912
Combustion Theory and Modelling
25
1
121
157
eprints
oai:upcommons.upc.edu:2117/1916432022-05-22T02:20:58Zcom_2117_184555com_2117_184544com_2117_28577com_2117_80515com_2117_23714com_2117_28578com_2117_15797col_2117_184721col_2117_80523col_2117_3055openAccess
Serpa, Matheus S.
Cruz, Eduardo HM
Diener, Matthias
Krause, Arthur M.
Navaux, Philippe
Panetta, Jairo
Farrés Coma, Albert
Rosas, Claudia
Hanzich, Mauricio
Universitat Politècnica de Catalunya. Doctorat en Arquitectura de Computadors
Barcelona Supercomputing Center
2020-06-26T09:02:08Z
2020-06-26T09:02:08Z
2019-01-17
Serpa, M. [et al.]. Optimization strategies for geophysics models on manycore systems. "International journal of high performance computing applications", 17 Gener 2019, vol. 33, núm. 3, p. 473-486.
1094-3420
http://hdl.handle.net/2117/191643
10.1177/1094342018824150
Many software mechanisms for geophysics exploration in oil and gas industries are based on wave propagation simulation. To perform such simulations, state-of-the-art high-performance computing architectures are employed, generating results faster with more accuracy at each generation. The software must evolve to support the new features of each design to keep performance scaling. Furthermore, it is important to understand the impact of each change applied to the software to improve the performance as most as possible. In this article, we propose several optimization strategies for a wave propagation model for six architectures: Intel Broadwell, Intel Haswell, Intel Knights Landing, Intel Knights Corner, NVIDIA Pascal, and NVIDIA Kepler. We focus on improving the cache memory usage, vectorization, load balancing, portability, and locality in the memory hierarchy. We analyze the hardware impact of the optimizations, providing insights of how each strategy can improve the performance. The results show that NVIDIA Pascal outperforms the other considered architectures by up to 8.5×.
Our research received funding from the EU H2020 Programme and from MCTI/RNP-Brazil under the HPC4E project, grant agreement 689772, as well as from CNPq and Capes.
Peer Reviewed
Postprint (author's final draft)
14 p.
eng
Àrees temàtiques de la UPC::Informàtica::Arquitectura de computadors
Geophysics
Memory management (Computer science)
Manycore systems
Vectorization
Memory hierarchy
HPC
Geofísica
Gestió de memòria (Informàtica)
Optimization strategies for geophysics models on manycore systems
Article
https://journals.sagepub.com/doi/10.1177/1094342018824150
info:eu-repo/grantAgreement/EC/H2020/689772/EU/HPC for Energy/HPC4E
Open Access
28458631
Serpa, M.; Cruz, E.; Diener, M.; Krause, A.; Navaux, P.; Panetta, J.; Farrés, A.; Rosas, C.; Hanzich, M.
International journal of high performance computing applications
33
3
473
486
eprints
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/1668632020-10-11T04:41:40Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Barcons, Jordi
Avila, Matias
Folch, Arnau
Barcelona Supercomputing Center
2019-07-25T10:43:00Z
2019-07-25T10:43:00Z
2019-02
Barcons, J.; Avila, M.; Folch, A. Diurnal cycle RANS simulations applied to wind resource assessment. "Wind energy", Febrer 2019, vol. 22, núm. 2, p. 269-282.
1095-4244
http://hdl.handle.net/2117/166863
10.1002/we.2283
Microscale computational fluid dynamics (CFD) models can be used for wind resource assessment on complex terrains. These models generally assume neutral atmospheric stratification, an assumption that can lead to inaccurate modeling results and to large uncertainties at certain sites. We propose a methodology for wind resource evaluation based on unsteady Reynolds averaged Navier‐Stokes (URANS) simulations of diurnal cycles including the effect of thermal stratification. Time‐dependent boundary conditions are generated by a 1D precursor to drive 3D diurnal cycle simulations for a given geostrophic wind direction sector. Time instants of the cycle representative of four thermal stability regimes are sampled within diurnal cycle simulations and combined with masts time series to obtain the wind power density (WPD). The methodology has been validated on a complex site instrumented with seven met masts. The WPD spatial distribution is in good agreement with observations with the mean absolute error improving 17.1% with respect to the neutral stratification assumption.
This work has been partially supported by the three EU H2020 projects, New European Wind Atlas ERA‐NET PLUS (NEWA, FP7‐ENERGY.2013.10.1.2, European Commission's grant agreement 618122), High Performance Computing for Energy (HPC4E, grant agreement 689772), and the Energy oriented Centre of Excellence (EoCoE, grant agreement 676629), and the SEDAR (“Simulación eólica de alta resolución”) project. Jordi Barcons is grateful to a PhD fellowship from the Industrial Doctorates Plan of the Government of Catalonia (Ref. eco/2497/2013). We also thank Iberdrola Renovables Energa S.A. and Impulsora Latinoamericana de Energa Renovables S.A. for providing the access to Puebla met masts data for validation and to Luis Prieto and Daniel Paredes for their help. We also thank the reviewers for their productive comments and observations.
Peer Reviewed
Postprint (published version)
14 p.
eng
Wiley
Attribution-NonCommercial-NoDerivs 4.0 Spain
http://creativecommons.org/licenses/by-nc-nd/4.0/es/
Open Access
Àrees temàtiques de la UPC::Enginyeria dels materials
Embedded computer systems
Diurnal cycle
Thermal effects
Thermal stability
Wind resource assessment
Wind power density
Sistemes incrustats (Informàtica)
Diurnal cycle RANS simulations applied to wind resource assessment
Article
https://onlinelibrary.wiley.com/doi/10.1002/we.2283
info:eu-repo/grantAgreement/EC/FP7/618122/EU/New European Wind Atlas Joint Programme/NEWA
info:eu-repo/grantAgreement/EC/H2020/689772/EU/HPC for Energy/HPC4E
info:eu-repo/grantAgreement/EC/H2020/676629/EU/Energy oriented Centre of Excellence for computer applications/EoCoE
Wind energy
22
2
269
282
eprints
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/888732020-10-11T04:45:56Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Costa, Antonio
Suzuki, Yujiro J.
Cerminara, Matteo
Devenish, Ben J.
Ongaro, Tomaso E.
Herzog, Michael
van Eaton, Alexa R.
Denby, L. C.
Bursik, Marcus I.
Vitturi, M. de' Michieli
Engwell, Samantha L.
Neri, Augusto
Barsotti, Sara
Folch, Arnau
Macedonio, Giovanni V.
Girault, Frédéric
Carazzo, Guillaume
Tait, Steve R.
Kaminski, Édouard
Mastin, Larry G.
Woodhouse, Mark J.
Phillips, Jeremy C.
Hogg, Andrew J. C.
Degruyter, Wim
Bonadonna, Constanza
Barcelona Supercomputing Center
2016-07-18T12:22:31Z
2018-10-16T00:30:45Z
2016-02-06
COSTA, ANTONIO [et al.]. Results of the eruptive column model inter-comparison study. "Journal of Volcanology and Geothermal Research", 06 Febrer 2016.
0377-0273
http://hdl.handle.net/2117/88873
10.1016/j.jvolgeores.2016.01.017
To improve our understanding of the physics of volcanic plumes and their interaction with the atmosphere, increasingly sophisticated numerical models of eruptive columns have been developed by a growing number of research groups. These models are different in their design and scope, but all have the fundamental goal of characterizing the dynamics of volcanic plume formation and ultimately providing estimates of source conditions. Descriptions of volcanic columns (or plumes, we use the terms interchangeably in this paper) are important for hazard mitigation because they can be used in models that forecast the dispersion of ash and hazardous gases in the atmosphere. The accuracy of tephra dispersal forecasts is strongly dependent on the source term, which describes both the mass eruption rate of volcanic emissions and their initial vertical distribution in the atmosphere. However, until now there has not been a systematic effort to compare how these source terms are derived. For this study, we have brought together 13 different models to perform a set of simulations using the same input parameters, so that results can be meaningfully compared and evaluated. The motivation is twofold: (1) to provide a conceptual overview of what the various models can accomplish, and (2) to target specific areas for further exploration by the research community as a whole.
AC was partially supported by a grant of the International Research Promotion Office Earthquake Research Institute, the University of Tokyo. AC, GM, AN, MdMV, TEO and MC were partially supported by the EU-funded project MEDiterranean SUpersite Volcanoes (MEDSUV) (grant n. 308665). AVE acknowledges NSF Postdoctoral Fellowship
EAR1250029 and a USGS Mendenhall Fellowship. MIB was supported partially by NSF-IDR and AFOSR. AJH, MJW, and JCP were partially supported bythe NERC-funded projectVanaheim (grantno. NE/I01554X/1) and the EU-funded project FutureVolc (grant no. 308377). FG, GC, ST, and EK were partially supported by INSU, CNRS. We wish to thank T.
Koyaguchi, S. Solovitz, and an anonymous reviewer for constructive suggestions that improved the quality of the manuscript.
Peer Reviewed
Postprint (author's final draft)
eng
Elsevier
Attribution-NonCommercial-NoDerivs 4.0 International License
https://creativecommons.org/licenses/by-nc-nd/4.0/
Open Access
Àrees temàtiques de la UPC::Enginyeria biomèdica
Volcanism
Volcanic eruption prediction
Forecasting--Data processing
Explosive volcanism
Eruptive plumes dynamics
Fluid dynamic models
Model intercomparison
Eruption source parameters
Activitat volcànica--Previsió
Erupcions volcàniques
Results of the eruptive column model inter-comparison study
Article
http://www.sciencedirect.com.recursos.biblioteca.upc.edu/science/article/pii/S0377027316000366
info:eu-repo/grantAgreement/EC/FP7/308377/EU/A European volcanological supersite in Iceland: a monitoring system and network for the future/FUTUREVOLC
info:eu-repo/grantAgreement/EC/FP7/308665/EU/MEDiterranean SUpersite Volcanoes/MED-SUV
Journal of Volcanology and Geothermal Research
326
eprints
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3455682021-05-16T21:54:45Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Wang, Zhinuo J
Santiago, Alfonso
Zhou, Xin
Wang, Lei
Margara, Francesca
Levrero-Florencio, Francesc
Das, Arka
Kelly, Chris
Dall'Armellina, Erica
Vázquez, Mariano
Rodriguez, Blanca
Barcelona Supercomputing Center
2021-05-13T13:19:32Z
2021-05-13T13:19:32Z
2021-03
Wang, Z.J. [et al.]. Human biventricular electromechanical simulations on the progression of electrocardiographic and mechanical abnormalities in post-myocardial infarction. "EP-Europace", Març 2021, vol. 23, núm. Issue Supplement_1, p. i143-i152.
1099-5129
http://hdl.handle.net/2117/345568
10.1093/europace/euaa405
Aims
Develop, calibrate and evaluate with clinical data a human electromechanical modelling and simulation framework for multiscale, mechanistic investigations in healthy and post-myocardial infarction (MI) conditions, from ionic to clinical biomarkers.
Methods and results
Human healthy and post-MI electromechanical simulations were conducted with a novel biventricular model, calibrated and evaluated with experimental and clinical data, including torso/biventricular anatomy from clinical magnetic resonance, state-of-the-art human-based membrane kinetics, excitation–contraction and active tension models, and orthotropic electromechanical coupling. Electromechanical remodelling of the infarct/ischaemic region and the border zone were simulated for ischaemic, acute, and chronic states in a fully transmural anterior infarct and a subendocardial anterior infarct. The results were compared with clinical electrocardiogram and left ventricular ejection fraction (LVEF) data at similar states. Healthy model simulations show LVEF 63%, with 11% peak systolic wall thickening, QRS duration and QT interval of 100 ms and 330 ms. LVEF in ischaemic, acute, and chronic post-MI states were 56%, 51%, and 52%, respectively. In linking the three post-MI simulations, it was apparent that elevated resting potential due to hyperkalaemia in the infarcted region led to ST-segment elevation, while a large repolarization gradient corresponded to T-wave inversion. Mechanically, the chronic stiffening of the infarct region had the benefit of improving systolic function by reducing infarct bulging at the expense of reducing diastolic function by inhibiting inflation.
Conclusion
Our human-based multiscale modelling and simulation framework enables mechanistic investigations into patho-physiological electrophysiological and mechanical behaviour and can serve as testbed to guide the optimization of pharmacological and electrical therapies.
This work was funded by a Wellcome Trust Fellowship in Basic Biomedical Sciences to B.R. (214290/Z/18/Z), Personalised In-Silico Cardiology (PIC) project, European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement 764738, the CompBioMed 1 and 2 Centre of Excellence in Computational Biomedicine (European Commission Horizon 2020 research and innovation programme, grant agreements No. 675451 and No. 823712), an NC3Rs Infrastructure for Impact Award (NC/P001076/1), the TransQST project (Innovative Medicines Initiative 2 Joint Undertaking under grant agreement No 116030, receiving support from the European Union’s Horizon 2020 research and innovation programme and EFPIA), and the Oxford BHF Centre of Research Excellence (RE/13/1/30181). This paper is part of a supplement supported by an unrestricted grant from the Theo-Rossi di Montelera (TRM) foundation.
Peer Reviewed
Postprint (published version)
10 p.
eng
Oxford University Press
Attribution 3.0 Spain
Attribution 4.0 International (CC BY 4.0)
http://creativecommons.org/licenses/by/3.0/es/
https://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Informàtica::Arquitectura de computadors::Arquitectures paral·leles
Computer simulation
Electrocardiograms
Myocardial infarction
Computer modelling
Electromechanical simulations
Myocardial infarction
Electrocardiogram
Ejection fraction
Simulació per ordinador
Human biventricular electromechanical simulations on the progression of electrocardiographic and mechanical abnormalities in post-myocardial infarction
Article
https://academic.oup.com/europace/article/23/Supplement_1/i143/6158569
info:eu-repo/grantAgreement/EC/H2020/675451/EU/A Centre of Excellence in Computational Biomedicine/CompBioMed
info:eu-repo/grantAgreement/EC/H2020/823712/EU/A Centre of Excellence in Computational Biomedicine/CompBioMed2
EP-Europace
23
Issue Supplement_1
i143
i152
eprints
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/1097842020-07-23T23:27:50Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Mohr, Stephan
Dawson, William
Wagner, Michael
Caliste, Damien
Nakajima, Takahito
Genovese, Luigi
Barcelona Supercomputing Center
2017-11-03T15:47:01Z
2018-09-05T00:30:18Z
2017-09-05
Mohr, S. [et al.]. Efficient Computation of Sparse Matrix Functions for Large-Scale Electronic Structure Calculations: The CheSS Library. "Journal of Chemical Theory and Computation", 5 Setembre 2017, vol. 13, núm. 10, p. 4684-4698.
1549-9618
http://hdl.handle.net/2117/109784
10.1021/acs.jctc.7b00348
We present CheSS, the “Chebyshev Sparse Solvers” library, which has been designed to solve typical problems arising in large-scale electronic structure calculations using localized basis sets. The library is based on a flexible and efficient expansion in terms of Chebyshev polynomials and presently features the calculation of the density matrix, the calculation of matrix powers for arbitrary powers, and the extraction of eigenvalues in a selected interval. CheSS is able to exploit the sparsity of the matrices and scales linearly with respect to the number of nonzero entries, making it well-suited for large-scale calculations. The approach is particularly adapted for setups leading to small spectral widths of the involved matrices and outperforms alternative methods in this regime. By coupling CheSS to the DFT code BigDFT, we show that such a favorable setup is indeed possible in practice. In addition, the approach based on Chebyshev polynomials can be massively parallelized, and CheSS exhibits excellent scaling up to thousands of cores even for relatively small matrix sizes.
We gratefully acknowledge the support of the MaX (SM) and POP (MW) projects, which have received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement
No. 676598 and 676553, respectively. This work was also supported by the Energy oriented Centre of Excellence (EoCoE), grant agreement number 676629, funded within the Horizon2020 framework of the European
Union, as well as by the Next-Generation Supercomputer project (the K computer project) and the FLAGSHIP2020 within the priority study5 (Development of new fundamental technologies for high-efficiency
energy creation, conversion/storage and use) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan. We (LG, DC, WD, TN) gratefully acknowledge the joint CEA-RIKEN collaboration action.
Peer Reviewed
Postprint (author's final draft)
15 p.
eng
American Chemical Society
Attribution-NonCommercial-NoDerivs 3.0 Spain
http://creativecommons.org/licenses/by-nc-nd/3.0/es/
Open Access
Àrees temàtiques de la UPC::Enginyeria elèctrica
Parallel processing (Electronic computers)
Chebyshev Sparse Solvers
Large scale electronic structure calculations
Sparse matrices
Processament en paral·lel (Ordinadors)
Efficient Computation of Sparse Matrix Functions for Large-Scale Electronic Structure Calculations: The CheSS Library
Article
http://pubs.acs.org/doi/abs/10.1021/acs.jctc.7b00348
info:eu-repo/grantAgreement/EC/H2020/676598/EU/Materials design at the eXascale/MaX
info:eu-repo/grantAgreement/EC/H2020/676553/EU/Performance Optimisation and Productivity/POP
info:eu-repo/grantAgreement/EC/H2020/676629/EU/Energy oriented Centre of Excellence for computer applications/EoCoE
info:eu-repo/grantAgreement
Journal of Chemical Theory and Computation
13
10
4684
4698
eprints
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3460972022-05-08T02:16:05Zcom_2117_184561com_2117_184544com_2117_28577com_2117_80515com_2117_23714com_2117_28578com_2117_15797col_2117_184693col_2117_80523col_2117_3055openAccess
Graells Garrido, Eduardo
Serra Burriel, Feliu
Rowe, Francisco
Cucchietti, Fernando
Reyes Valenzuela, Patricio Alejandro
Universitat Politècnica de Catalunya. Doctorat en Estadística i Investigació Operativa
Barcelona Supercomputing Center
2021-05-26T11:14:31Z
2021-05-26T11:14:31Z
2021-05-05
Graells, E. [et al.]. A city of cities: Measuring how 15-minutes urban accessibility shapes human mobility in Barcelona. "PloS one", 5 Maig 2021, vol. 16, núm. 5, article e0250080, p. 1-21.
1932-6203
http://hdl.handle.net/2117/346097
10.1371/journal.pone.0250080
As cities expand, human mobility has become a central focus of urban planning and policy making to make cities more inclusive and sustainable. Initiatives such as the “15-minutes city” have been put in place to shift the attention from monocentric city configurations to polycentric structures, increasing the availability and diversity of local urban amenities. Ultimately they expect to increase local walkability and increase mobility within residential areas. While we know how urban amenities influence human mobility at the city level, little is known about spatial variations in this relationship. Here, we use mobile phone, census, and volunteered geographical data to measure geographic variations in the relationship between origin-destination flows and local urban accessibility in Barcelona. Using a Negative Binomial Geographically Weighted Regression model, we show that, globally, people tend to visit neighborhoods with better access to education and retail. Locally, these and other features change in sign and magnitude through the different neighborhoods of the city in ways that are not explained by administrative boundaries, and that provide deeper insights regarding urban characteristics such as rental prices. In conclusion, our work suggests that the qualities of a 15-minutes city can be measured at scale, delivering actionable insights on the polycentric structure of cities, and how people use and access this structure.
E.G-G., F.S-B., F.M.C. and P.R. were partly supported by the H2020 IoTwins project (Distributed Digital Twins for industrial SMEs: a big-data platform) funded by the EU under the call ICT-11-2018-2019, Grant Agreement No 857191. E.G-G. was partly funded by ANID Fondecyt de Iniciación 11180913.
Peer Reviewed
Postprint (published version)
21 p.
eng
Public Library of Science (PLOS)
Attribution 4.0 International
https://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Matemàtiques i estadística::Estadística aplicada
Àrees temàtiques de la UPC::Desenvolupament humà i sostenible::Desenvolupament sostenible::Mobilitat sostenible
Big data
Regression analysis
Sustainable development
Human mobility
Barcelona
“15-minutes city”
Dades massives
Anàlisi de regressió
Mobilitat sostenible
Desenvolupament sostenible
A city of cities: Measuring how 15-minutes urban accessibility shapes human mobility in Barcelona
Article
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0250080
31753945
Graells, E.; Serra, F.; Rowe, F.; Cucchietti, F.; Reyes, P.
PloS one
16
5, article e0250080
1
21
eprints
oai:upcommons.upc.edu:2117/3432192023-08-06T03:04:08Zcom_2117_3911com_2117_28579com_2117_28577com_2117_80515com_2117_23714com_2117_28578col_2117_3912col_2117_80523openAccess
Castillo Reyes, Octavio
Queralt Capdevila, Pilar
Marcuello Pascual, Alex
Ledo Fernandez, Juanjo
Barcelona Supercomputing Center
Universitat Politècnica de Catalunya. Departament d'Arquitectura de Computadors
2021-04-07T14:10:06Z
2021-04-07T14:10:06Z
2021
Castillo, O. [et al.]. Land CSEM simulations and experimental test using metallic casing in a geothermal exploration context: Vallès Basin (NE Spain) case study. "IEEE Transactions on Geoscience and Remote Sensing", 2021,
1558-0644
http://hdl.handle.net/2117/343219
10.1109/TGRS.2021.3069042
Controlled-source electromagnetic (CSEM) measurements are complementary data for magnetotelluric (MT) characterization although its methodology on land is not sufficiently developed and tested as in marine environments. Acquiring expertise in CSEM is crucial for surveys in places where MT cannot be performed due to high levels of cultural noise. To acquire that expertise, we perform CSEM experiments in the Vallès fault [Northeast (NE), Spain], where MT results have been satisfactory and allow us to verify the CSEM results. The Vallès basin is relevant for potential heat generation because of the presence of several geothermal anomalies and its nearby location in urban areas. In this article, we present the experimental setup for that region, a 2-D joint MT+CSEM inverse model, several 3-D CSEM simulations in the presence of metallic casing, and its comparison with real data measurements. We employ a parallel and high-order vector finite element algorithm to discretize the governing equations. By using an adapted meshing strategy, different scenarios are simulated to study the influence of the source position/direction and the conductivity model in a metallic casing presence. An excellent agreement between the simulated data and analytical/real field data demonstrates the feasibility of study metallic structures in realistic configurations. Our numerical results confirm that metallic casing strongly influences electromagnetic (EM) responses, making surface measurements more sensitive to resistivity variations near the metallic structure. It could be beneficial getting higher signal-to-noise ratios and sensitivity to deep targets. However, such a casing effect depends on the input model (e.g., conductivity contrasts, frequency, and geometry).
This work was been developed in the frame of GEOURBAN project (PCI2018-092943 and PCI2018-093186). This work has received also partial funding from the European Union's Horizon 2020 programme under the Marie Sklodowska-Curie grant agreement N777778. Also, the research leading to these results has received funding from the European Union's Horizon 2020 programme, grant agreement N828947, and from the Mexican Department of Energy, CONACYT-SENER Hidrocarburos grant agreement N B-S-69926. Furthermore, this project has been 65% cofinanced by the European Regional Development Fund (ERDF) through the Interreg V-A Spain-France-Andorra program (POCTEFA2014-2020). POCTEFA aims to reinforce the economic and social integration of the French-Spanish-Andorran border. Its support is focused on developing economic, social and environmental cross-border activities through joint strategies favouring sustainable territorial development.
The authors would like to thank the Editors-in-Chief and to both reviewers for their valuable comments and suggestions that helped to improve the manuscript’s quality. This work benefitted from the valuable suggestions, comments, and proofreading of Dr. Josep de la Puente (BSC).
Peer Reviewed
Postprint (author's final draft)
13 p.
eng
Institute of Electrical and Electronics Engineers
Àrees temàtiques de la UPC::Informàtica::Aplicacions de la informàtica::Aplicacions informàtiques a la física i l‘enginyeria
High performance computing
Mathematical modeling and computation
Geology
Controlled-source electromagnetic (CSEM)
Geothermal exploration
High-performance computing (HPC)
Metallic casing effects
Numerical modeling
Càlcul intensiu (Informàtica)
Models matemàtics
Land CSEM simulations and experimental test using metallic casing in a geothermal exploration context: Vallès Basin (NE Spain) case study
Article
https://ieeexplore.ieee.org/document/9394801
info:eu-repo/grantAgreement/EC/H2020/777778/EU/Multiscale Inversion of Porous Rock Physics using High-Performance Simulators: Bridging the Gap between Mathematics and Geophysics/MATHROCKS
info:eu-repo/grantAgreement/EC/H2020/828947/EU/Supercomputing and Energy for Mexico/ENERXICO
Open Access
31286393
IEEE Transactions on Geoscience and Remote Sensing
eprints
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/1003732020-07-23T23:27:50Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Schneider, M.
Johnson, T.
Dumont, R.
Eriksson, L.-G.
Giacomelli, L.
Girardo, J.-B.
Hellsten, T.
Khilkevitch, E.
Kiptily, V.G.
Koskela, T.
Mantsinen, M.
Nocente, M.
Salewski, M.
Sharapov, S.E.
Shevelev, A.E.
Jet Contributors
Barcelona Supercomputing Center
2017-01-31T11:52:12Z
2017-08-24T00:30:29Z
2016-08-24
Schneider, M. [et al.]. Modelling third harmonic ion cyclotron acceleration of deuterium beams for JET fusion product studies experiments. "Nuclear Fusion", 24 Agost 2016, vol. 56, núm. 11.
0029-5515
http://hdl.handle.net/2117/100373
10.1088/0029-5515/56/11/112022
Recent JET experiments have been dedicated to the studies of fusion reactions between deuterium (D) and Helium-3 (3He) ions using neutral beam injection (NBI) in synergy with third harmonic ion cyclotron radio-frequency heating (ICRH) of the beam. This scenario generates a fast ion deuterium tail enhancing DD and D3He fusion reactions. Modelling and measuring the fast deuterium tail accurately is essential for quantifying the fusion products. This paper presents the modelling of the D distribution function resulting from the NBI+ICRF heating scheme, reinforced by a comparison with dedicated JET fast ion diagnostics, showing an overall good agreement. Finally, a sawtooth activity for these experiments has been observed and interpreted using SPOT/RFOF simulations in the framework of Porcelli's theoretical model, where NBI+ICRH accelerated ions are found to have a strong stabilizing effect, leading to monster sawteeth.
This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014-2018 under grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission.
Peer Reviewed
Postprint (author's final draft)
23 p.
eng
IOP Publishing
Àrees temàtiques de la UPC::Enginyeria biomèdica
Plasma dynamics
Fusion reactions
Fusion reactions
Plasma heating
Plasma (Gasos ionitzats)--Aplicacions industrials
Modelling third harmonic ion cyclotron acceleration of deuterium beams for JET fusion product studies experiments
Article
http://iopscience.iop.org/article/10.1088/0029-5515/56/11/112022
info:eu-repo/grantAgreement/EC/H2020/633053/EU/Implementation of activities described in the Roadmap to Fusion during Horizon 2020 through a Joint programme of the members of the EUROfusion consortium/EUROfusion
Open Access
Nuclear Fusion
56
11
112022
eprints
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3459242021-05-23T20:11:24Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Graells Garrido, Eduardo
Peña Araya, Vanessa
Bravo, Loreto
Barcelona Supercomputing Center
2021-05-19T13:31:58Z
2021-05-19T13:31:58Z
2020
Graells Garrido, E.; Peña Araya, V.; Bravo, L. Adoption-Driven Data Science for Transportation Planning: Methodology, Case Study, and Lessons Learned †. "Sustainability", 2020, vol. 12, núm. 15, 6001.
2071-1050
http://hdl.handle.net/2117/345924
10.3390/su12156001
The rising availability of digital traces provides a fertile ground for data-driven solutions to problems in cities. However, even though a massive data set analyzed with data science methods may provide a powerful and cost-effective solution to a problem, its adoption by relevant stakeholders is not guaranteed due to adoption barriers such as lack of interpretability and interoperability. In this context, this paper proposes a methodology toward bridging two disciplines, data science and transportation, to identify, understand, and solve transportation planning problems with data-driven solutions that are suitable for adoption by urban planners and policy makers. The methodology is defined by four steps where people from both disciplines go from algorithm and model definition to the development of a potentially adoptable solution with evaluated outputs. We describe how this methodology was applied to define a model to infer commuting trips with mode of transportation from mobile phone data, and we report the lessons learned during the process.
E.G-G. was partially funded by CONICYT Fondecyt de Iniciación #11180913.
Peer Reviewed
Postprint (published version)
17p.
eng
MDPI
Attribution 3.0 Spain
Attribution 4.0 International (CC BY 4.0)
http://creativecommons.org/licenses/by/3.0/es/
https://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Informàtica::Aspectes socials
Data transmission systems
Data services (Database management)
Transportation
Transportation
Urban mobility
Data science;
Mobile phone data
Dades -- Transmissió
Adoption-Driven Data Science for Transportation Planning: Methodology, Case Study, and Lessons Learned †
Article
https://www.mdpi.com/2071-1050/12/15/6001
6001
Sustainability
12
15
eprints
oai:upcommons.upc.edu:2117/3693492023-09-10T04:22:56Zcom_2117_80516com_2117_23714com_2117_28578com_2117_28577com_2117_3911com_2117_28579com_2117_3123com_2117_28581com_2117_80515com_2117_15797col_2117_80530col_2117_3912col_2117_3124col_2117_80523col_2117_3055
Houzeaux, Guillaume
Badia Sala, Rosa Maria
Borrell Pol, Ricard
Dosimont, Damien
Ejarque Artigas, Jorge
García Gasulla, Dario
López Herrero, Víctor
Universitat Politècnica de Catalunya. Departament d'Arquitectura de Computadors
Barcelona Supercomputing Center
Universitat Politècnica de Catalunya. CAP - Grup de Computació d'Altes Prestacions
2022-06-30T08:56:40Z
2022-09-15
2024-06-28
Houzeaux, G. [et al.]. Dynamic resource allocation for efficient parallel CFD simulations. "Computers and fluids", 2022, vol. 245, article 105577, p. 1-13.
0045-7930
https://arxiv.org/abs/2112.09560
http://hdl.handle.net/2117/369349
10.1016/j.compfluid.2022.105577
CFD users of supercomputers usually resort to rule-of-thumb methods to select the number of subdomains (partitions) when relying on MPI-based parallelization. One common approach is to set a minimum number of elements or cells per subdomain, under which the parallel efficiency of the code is “known” to fall below a subjective level, say 80%. The situation is even worse when the user is not aware of the “good” practices for the given code and a huge amount of resources can thus be wasted. This work presents an elastic computing methodology that adapts at runtime the resources allocated to a simulation automatically. The criterion to control the required resources is based on a runtime measure of the communication efficiency of the execution. According to some analytical estimates, the resources are then expanded or reduced to fulfill this criterion and eventually execute an efficient simulation.
This work has been supported by the Spanish Government (PID2019- 107255GB); by Generalitat de Catalunya (contract 2014-SGR-1051); by the European Commission H2020 project POP CoE (GA n. 824080); by the European Commission H2020 project CompBioMed CoE (GA n. 823712) and by the European Commission and the EuroHPC JU under contract 955558 (eFlows4HPC project).
Peer Reviewed
Postprint (author's final draft)
29 p.
eng
Elsevier
Attribution-NonCommercial-NoDerivatives 4.0 International
http://creativecommons.org/licenses/by-nc-nd/4.0/
Restricted access - publisher's policy
Àrees temàtiques de la UPC::Informàtica::Arquitectura de computadors
Resource allocation
Computational fluid dynamics
Supercomputers
CFD
High performance computing
Elastic computing
Parallel efficiency
MPI
CFD
Assignació de recursos
Dinàmica de fluids computacional
Supercomputadors
Dynamic resource allocation for efficient parallel CFD simulations
Article
https://www.sciencedirect.com/science/article/pii/S0045793022001918?via%3Dihub
info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PID2019-107255GB-C21/ES/BSC - COMPUTACION DE ALTAS PRESTACIONES VIII/
info:eu-repo/grantAgreement/EC/H2020/824080/EU/Performance Optimisation and Productivity 2/POP2
info:eu-repo/grantAgreement/EC/H2020/823712/EU/A Centre of Excellence in Computational Biomedicine/CompBioMed2
info:eu-repo/grantAgreement/EC/H2020/955558/EU/Enabling dynamic and Intelligent workflows in the future EuroHPCecosystem/eFlows4HPC
33980289
Houzeaux, G.; Badia, R.M.; Borrell, R.; Dosimont, D.; Ejarque, J.; García, D.; López, V.
Computers and fluids
245
article 105577
1
13
eprints
10.13039/501100011033
Agencia Estatal de Investigación
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3671382022-10-09T03:22:10Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Taylor, David
Mantsinen, Mervi J.
Gallart Escolà, Dani
Manyer Fuertes, Jordi
Sirén, P.
JET Contributors
Barcelona Supercomputing Center
2022-05-10T10:10:26Z
2022-05-10T10:10:26Z
2022-04
Taylor, D. [et al.]. Effect of inclusion of pitch-angle dependence on a simplified model of RF deposition in tokamak plasma. "Plasma Physics and Controlled Fusion", Abril 2022, vol. 64, 055015.
0741-3335
1361-6587
http://hdl.handle.net/2117/367138
10.1088/1361-6587/ac5e6b
Using the PION ICRH modelling code and comparisons against JET tokamak experiments, the effect of including pitch angle dependence within the RF diffusion operator on the fast ion particle distribution functions is quantified. It is found to be of greatest importance in cases of higher harmonic heating and lower heating ion mass, resulting in faster drop-off of the distribution's high energy tail. We see differences of several orders of magnitude in the high-energy range and significant non-linear alterations by several tens of percent to ion species power partition. ITER scenario operational parameters are also considered, and this improved treatment is shown to benefit anticipated ITER scenarios with second harmonic hydrogen heating, according to our predictions. PION's combination of benchmarked simplified wave physics and Fokker-Planck treatment offers modelling advantages. Since including the pitch angle dependence in the RF diffusion operator has not led to a significant increase in the required computing time when modelling different ICRF schemes in JET discharges, it has been made available within the production code.
The CCFE part of this work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014–2018 and 2019–2020 under Grant Agreement No. 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission.
The BSC part of this project is co-financed by the European Union Regional Development Fund within the framework of the ERDF Operational Program of Catalonia 2014–2020 with a grant of 50% of total cost eligible.
The authors are grateful to Jacob Eriksson for assistance with experimental data, to Lars-Göran Eriksson for discussions on the implementation of the new features, and to Colin Roach and Michael Fitzgerald for valuable comments on the manuscript.
Peer Reviewed
Postprint (published version)
11 p.
eng
IOP Publishing
Attribution 3.0 Spain
Attribution 4.0 International (CC BY 4.0)
Attribution 4.0 International (CC BY 4.0)
http://creativecommons.org/licenses/by/3.0/es/
https://creativecommons.org/licenses/by/4.0/
https://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Física::Física de fluids::Física de plasmes
Tokamaks
Fusion
Tokamak
ICRF
PION
Fast ions
Neutron
Spectroscopy
JET
ITER
Ions
Effect of inclusion of pitch-angle dependence on a simplified model of RF deposition in tokamak plasma
Article
https://iopscience.iop.org/article/10.1088/1361-6587/ac5e6b
info:eu-repo/grantAgreement/EC/H2020/633053/EU/Implementation of activities described in the Roadmap to Fusion during Horizon 2020 through a Joint programme of the members of the EUROfusion consortium/EUROfusion
055015
Plasma Physics and Controlled Fusion
64
eprints
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3646382022-03-27T15:52:02Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Mullins, Rita
Gutiérrez Moreno, José Julio
Nolan, Michael
Barcelona Supercomputing Center
2022-03-21T15:23:36Z
2022-03-21T15:23:36Z
2022-02
Mullins, R.; Gutiérrez Moreno, J.J.; Nolan, M. Origin of enhanced thermal atomic layer etching of amorphous HfO2. "Journal of Vacuum Science and Technology A (JVST A)", Febrer 2022, vol. 40, núm. 2, 022604.
0734-2101
http://hdl.handle.net/2117/364638
10.1116/6.0001614
HfO2 is a high-k material that is used in semiconductor devices. Atomic-level control of material processing is required for the fabrication of thin films of high-k materials at nanoscale device sizes. Thermal atomic layer etching (ALE) of metal oxides, in which up to one monolayer of material can be removed, can be achieved by sequential self-limiting fluorination and ligand-exchange reactions at elevated temperatures. First-principles-based atomic-level simulations using density functional theory can give deep insights into the precursor chemistry and the reactions that drive the etching of metal oxides. A previous study examined the hydrogen fluoride (HF) pulse in the first step in the thermal ALE process of crystalline HfO2 and ZrO2. This study examines the HF pulse on amorphous HfO2 using first-principles simulations. The Natarajan–Elliott analysis, a thermodynamic methodology, is used to compare reaction models representing the self-limiting and spontaneous etch processes taking place during an ALE pulse. For the HF pulse on amorphous HfO2, we found that thermodynamic barriers impeding spontaneous etching are present at ALE relevant temperatures. HF adsorption calculations on the amorphous oxide surface are studied to understand the mechanistic details of the HF pulse. An HF molecule adsorbs dissociatively by forming Hf–F and O–H bonds. HF coverages ranging from 1.1 ± 0.3 to 18.0 ± 0.3 HF/nm2 are investigated, and a mixture of molecularly and dissociatively adsorbed HF molecules is present at higher coverages. A theoretical etch rate of −0.82 ± 0.02 Å/cycle for amorphous HfO2 was calculated using a maximum coverage of 9.0 ± 0.3 Hf–F/nm2. This theoretical etch rate is greater than the theoretical etch rate for crystalline HfO2 that we previously calculated at −0.61 ± 0.02 Å/cycle. Undercoordinated atoms and void regions in amorphous HfO2 allow for more binding sites during fluorination, whereas crystalline HfO2 has a limited number of adsorption sites.
We acknowledge support for this work from the LAM Research and the Science Foundation Ireland–NSF China Partnership Program, NITRALD Grant No. 17/NSFC/5279. We are grateful for access to Tyndall computing facilities supported by SFI and the Irish Centre for High-End Computing, www.ichec.ie. J.J.G.M. acknowledges financial support from the FusionCAT project (No. 001-P-001722) co-financed by the European Union Regional Development Fund within the framework of the ERDF Operational Program of Catalonia 2014–2020 with a grant of 50% of total cost eligible, and the access to HPC resources at the National Supercomputing Center in Shenzhen, acquired with funding from the Postdoctoral Science Foundation of China (Grant No. 2018M643152).
Peer Reviewed
Postprint (published version)
11 p.
eng
American Vacuum Society
https://aip-prod-cdn.literatumonline.com/journals/content/jva/2022/jva.2022.40.issue-2/6.0001614/20220228/suppl/supplemental_material_ahfo2_ale_modelling.pdf?b92b4ad1b4f274c70877518511abb28bed2c6f7421a565d9f7a5b3e3f5a40bc644191f5cacfb3cc9bc55304dc1c37156f8ea51e147a9f9df7ba4490c43ba408af9a38907dbd79182611f2f4f1602f33a306c6ff205e5c2c75662c0afbda550b42623be4b1d3774d9ef69f863ffb0b397eb65eb858aa89df60194efef8d8639d42a400e803659110d15d886fd5471aa8d16d62f72c372a0de8035b68ba8a17d4ade00b52999
https://avs.scitation.org/doi/10.1116/6.0001614
Attribution 3.0 Spain
Attribution 4.0 International (CC BY 4.0)
http://creativecommons.org/licenses/by/3.0/es/
https://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Informàtica::Aplicacions de la informàtica::Aplicacions informàtiques a la física i l‘enginyeria
Thin films
Semiconductor devices
Atomic layer deposition
HfO2
Semiconductor devices
Thermal atomic layer etching (ALE)
Nanoescala (Electrònica)
Origin of enhanced thermal atomic layer etching of amorphous HfO2
Article
022604
Journal of Vacuum Science and Technology A (JVST A)
40
2
eprints
oai:upcommons.upc.edu:2117/3592542023-12-24T01:27:13Zcom_2117_79679com_2117_28579com_2117_28577com_2117_184560com_2117_184544com_2117_2072com_2117_28581com_2117_80515com_2117_23714com_2117_28578com_2117_15797col_2117_79694col_2117_184705col_2117_6145col_2117_80523col_2117_3055openAccess
Jiménez Ramos, Albert
Gargallo Peiró, Abel
Roca Navarro, Francisco Javier
Universitat Politècnica de Catalunya. Doctorat en Matemàtica Aplicada
Universitat Politècnica de Catalunya. Departament d'Enginyeria Civil i Ambiental
Barcelona Supercomputing Center
Universitat Politècnica de Catalunya. LACÀN - Mètodes Numèrics en Ciències Aplicades i Enginyeria
2022-01-10T14:59:15Z
2023-12-24T01:27:13Z
2022-04
Jiménez-Ramos, A.; Gargallo, A.; Roca, X. Interpolation of subdivision features for curved geometry modeling. "Computer-aided design", Abril 2022, vol. 145, article 103185, p. 1-19.
0010-4485
http://hdl.handle.net/2117/359254
10.1016/j.cad.2021.103185
We present a nodal interpolation method to approximate a subdivision model. The main application is to model and represent curved geometry without gaps and preserving the required simulation intent. Accordingly, we devise the technique to maintain the necessary sharp features and smooth the indicated ones. This sharp-to-smooth modeling capability handles unstructured configurations of the simulation points, curves, and surfaces. The surfaces correspond to initial linear triangulations that determine the sharp point and curve features. The method automatically suggests a subset of sharp features to smooth which the user modifies to obtain a limit model preserving the initial points. This model reconstructs the curvature by subdivision of the initial mesh, with no need of an underlying curved geometry model. Finally, given a polynomial degree and a nodal distribution, the method generates a piece-wise polynomial representation interpolating the limit model. We show numerical evidence that this approximation, naturally aligned to the subdivision features, converges to the model geometrically with the polynomial degree for fair nodal distributions. We also apply the method to prescribe the curved boundary of a high-order volume mesh. We conclude that our sharp-to-smooth modeling capability leads to curved geometry representations with enhanced preservation of the simulation intent.
This project has received funding from the European Research Council (ERC) [http://dx.doi.org/10.13039/501100000781] under the European Union’s Horizon 2020 research and innovation programme under grant agreement No 715546. This work has also received funding from the Generalitat de Catalunya, Spain under grant number 2017 SGR 1731. The work of the third author has been partially supported by the Spanish Ministerio de Economía y Competitividad under the personal grant agreement RYC-2015-01633. Special thanks to Eloi Ruiz-Gironés.
Peer Reviewed
Postprint (author's final draft)
19 p.
eng
Attribution-NonCommercial-NoDerivatives 4.0 International
© 2021 Elsevier
https://creativecommons.org/licenses/by-nc-nd/4.0/
Open Access
Àrees temàtiques de la UPC::Matemàtiques i estadística::Geometria
Geometrical models
Mesh curving
Surrogate geometry
Geometry modeling
Subdivision
Blending
Models geomètrics
Interpolation of subdivision features for curved geometry modeling
Article
https://www.sciencedirect.com/science/article/abs/pii/S0010448521001834?via%3Dihub
info:eu-repo/grantAgreement/EC/H2020/715546/EU/Best Curved Adapted Meshes for Space-Time Flow Simulations/Tesseract
31297309
Jiménez-Ramos, A.; Gargallo, A.; Roca, X.
Computer-aided design
145
article 103185
1
19
eprints
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3287822021-08-25T00:29:54Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Arai, K
Kapoor, S
Bhatia, S
Carrasco Jiménez, José Carlos
Baldaro, Filippo
Cucchietti, Fernando
Barcelona Supercomputing Center
2020-09-16T08:32:39Z
2021-08-25T00:29:54Z
2020-08-25
Carrasco Jiménez, J.C.; Baldaro, F.; Cucchietti, F. Detection of anomalous patterns in water consumption: an overview of approaches. A: Intelligent Systems and Applications. IntelliSys 2020. "Advances in Intelligent Systems and Computing, vol 1250". Springer, Cham, 2020,
978-3-030-55179-7
http://hdl.handle.net/2117/328782
10.1007/978-3-030-55180-3_2
The water distribution system constantly aims at improving and efficiently distributing water to the city. Thus, understanding the nature of irregularities that may interrupt or exacerbate the service is at the core of their business model. The detection of technical and non-technical losses allows water companies to improve the sustainability and affordability of the service. Anomaly detection in water consumption is at present a challenging task. Manual inspection of data is tedious and requires a large workforce. Fortunately, the sector may benefit from automatized and intelligent workflows to reduce the amount of time required to identify abnormal water consumption. The aim of this research work is to develop a methodology to detect anomalies and irregular patterns of water consumption. We propose the use of algorithms of different nature that approach the problem of anomaly detection from different perspectives that go from searching deviations from typical behavior to identification of anomalous pattern changes in prolonged periods of time. The experiments reveal that different approaches to the problem of anomaly detection provide complementary clues to contextualize household water consumption. In addition, all the information extracted from each approach can be used in conjunction to provide insights for decision-making
This research work is cofounded by the European Regional Development Fund (FEDER) under the FEDER Catalonia Operative Programme 2014–2020 as part of the R+D Project from RIS3CAT Utilities 4.0 Community with reference code COMRDI16-1-0057.
Peer Reviewed
Postprint (author's final draft)
15 p.
eng
Springer, Cham
Àrees temàtiques de la UPC::Desenvolupament humà i sostenible::Política i gestió ambiental::Gestió de l'aigua
Water--Distribution
Water consumption
Decision making
Algorithms
Anomaly detection
Water consumption
Time series
Decision making
Aigua -- Abastament
Detection of anomalous patterns in water consumption: an overview of approaches
Part of book or chapter of book
https://link.springer.com/chapter/10.1007/978-3-030-55180-3_2
Open Access
Intelligent Systems and Applications. IntelliSys 2020
Advances in Intelligent Systems and Computing, vol 1250
1250
eprints
oai:upcommons.upc.edu:2117/3964612023-11-15T14:50:16Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Štancar, Žiga
K. Kirov, Krassimir
Auriemma, Fulvio
Kim, Hyun-Tae
Poradzinski, Michal
Gallart, Daniel
Mantsinen, Mervi J.
Barcelona Supercomputing Center
2023-11-15T14:47:43Z
2023-11-15T14:47:43Z
2023-11
Štancar, Ž. [et al.]. Overview of interpretive modelling of fusion performance in JET DTE2 discharges with TRANSP. "Nuclear Fusion", Novembre 2023, vol. 63, núm. 12.
1741-4326
http://hdl.handle.net/2117/396461
10.1088/1741-4326/ad0310
In the paper we present an overview of interpretive modelling of a database of JET-ILW 2021 D-T discharges using the TRANSP code. The main aim is to assess our capability of computationally reproducing the fusion performance of various D-T plasma scenarios using different external heating and D-T mixtures, and to understand the performance driving mechanisms. We find that interpretive simulations confirm a general power-law relationship between increasing external heating power and fusion output, which is supported by absolutely calibrated neutron yield measurements. A comparison of measured and computed D-T neutron rates shows that the calculations' discrepancy depends on the absolute neutron yield. The calculations are found to agree well with measurements for higher performing discharges with external heating power above ∼20 $\mathrm{MW}$, while low-neutron shots display an average discrepancy of around +40% compared to measured neutron yields. A similar trend is found for the ratio between thermal and beam-target fusion, where larger discrepancies are seen in shots with dominant beam-driven performance. We compare the observations to studies of JET-ILW D discharges, to find that on average the fusion performance is well modelled over a range of heating power, although an increased unsystematic deviation for lower-performing shots is observed. The ratio between thermal and beam-induced D-T fusion is found to be increasing weakly with growing external heating power, with a maximum value of $\gtrsim$1 achieved in a baseline scenario experiment. An evaluation of the fusion power computational uncertainty shows a strong dependence on the plasma scenario type and fusion drive characteristics, varying between ±25% and 35%. D-T fusion alpha simulations show that the ratio between volume-integrated electron and ion heating from alphas is $\lesssim$10 for the majority of analysed discharges. Alphas are computed to contribute between ∼15% and 40% to the total electron heating in the core of highest performing D-T discharges. An alternative workflow to TRANSP was employed to model JET D-T plasmas with the highest fusion yield and dominant non-thermal fusion component because of the use of fundamental radio-frequency heating of a large minority in the scenario, which is calculated to have provided ∼10% to the total fusion power.
This work has been carried out within the framework of the EUROfusion Consortium, funded by the European Union via the Euratom Research and Training Programme (Grant Agreement No. 101052200—EUROfusion). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Commission. Neither the European Union nor the European Commission can be held responsible for them. This work has been part-funded by the EPSRC Energy Programme with grant number EP/W006839/1.
The Barcelona Supercomputing Center part of this work has contributed through the Spanish National R&D Project PID2019-110854RB-I00 funded through MCIN/AEI/10.13039/501100011033. In addition BSC are grateful for the support received from the Departament de Recerca i Universitats de la Generalitat de Catalunya via the Research Group Fusion Group with code: 2021 SGR 00908.
The Laboratorio Nacional de Fusión contribution was funded in part via the Spanish National R&D Project PID2021-127727OB-I00 funded through MCIN/AEI /10.13039/501100011033.
Peer Reviewed
Postprint (published version)
"Article signat per 43 autors/es: Ž. Štancar, K.K. Kirov, F. Auriemma, H.-T. Kim, M. Poradziński, R. Sharma, R. Lorenzini, Z. Ghani, M. Gorelenkova, F. Poli, A. Boboc, S. Brezinsek, P. Carvalho, F.J. Casson, C.D. Challis, E. Delabie, D. Van Eester, M. Fitzgerald, J.M. Fontdecaba, D. Gallart, J. Garcia, L. Garzotti, C. Giroud, A. Kappatou, Ye.O. Kazakov, D.B. King, V.G. Kiptily, D. Kos, E. Lerche, E. Litherland-Smith, C.F. Maggi, P. Mantica, M.J. Mantsinen, M. Maslov, S. Menmuir, M. Nocente, H.J.C. Oliver, S.E. Sharapov, P. Sirén, E.R. Solano, H.J. Sun, G. Szepesi and JET Contributors"
30 p.
eng
IOP Publishing
Attribution 4.0 International
http://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Informàtica::Aplicacions de la informàtica::Aplicacions informàtiques a la física i l‘enginyeria
Nuclear fusion
Plasma heating
Deuterium-tritium plasma
Integrated modelling
Fusion performance
JET
TRANSP
Simulació per ordinador
Overview of interpretive modelling of fusion performance in JET DTE2 discharges with TRANSP
Article
https://iopscience.iop.org/article/10.1088/1741-4326/ad0310/meta
info:eu-repo/grantAgreement/EC/HE/101052200/EU/Implementation of activities described in the Roadmap to Fusion during Horizon Europe through a joint programme of the members of the EUROfusion consortium/EUROfusion
info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PID2019-110854RB-I00/ES/EVALUACION EXPERIMENTAL Y DESAROLLO DE CODIGOS DE MODELAJE PARA FUSION II/
Nuclear Fusion
63
12
eprints
10.13039/501100000780
European Commission
10.13039/501100011033
Agencia Estatal de Investigación
oai:upcommons.upc.edu:2117/3649632024-02-02T01:27:18Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Ruiz-Gironés, Eloi
Roca, Xevi
Barcelona Supercomputing Center
2022-03-29T12:47:26Z
2024-02-02T01:27:18Z
2022
Ruiz-Gironés, E.; Roca, X. Automatic Penalty and Degree Continuation for Parallel Pre-Conditioned Mesh Curving on Virtual Geometry. "Computer-Aided Design", 2022, vol. 146, 103208.
0010-4485
https://arxiv.org/abs/2211.08426
http://hdl.handle.net/2117/364963
10.1016/j.cad.2022.103208
We present a distributed parallel mesh curving method for virtual geometry. The main application is to generate large-scale curved meshes on complex geometry suitable for analysis with unstructured high-order methods. Accordingly, we devise the technique to generate geometrically accurate meshes composed of high-quality elements. To this end, we advocate for degree continuation on a penalty-based second-order optimizer that uses global tight tolerances to converge the distortion residuals. To reduce the method memory footprint, waiting time, and energy consumption, we combine three main ingredients. First, we propose a matrix-free GMRES solver pre-conditioned with successive over-relaxation by blocks to reduce the memory footprint three times. We also propose an adaptive penalty technique, to reduce the number of non-linear iterations. Third, we propose an indicator of the required linear solver tolerance to reduce the number of linear iterations. On thousands of cores, the method curves meshes composed of millions of quartic elements featuring highly stretched elements while matching a virtual topology.
This project has received funding from the European Research Council (ERC)[http://dx.doi.org/10.13039/501100000781] under the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 715546. This work has also received funding from the Generalitat de Catalunya,Spain under grant number 2017 SGR 1731. The work of Xevi Roca has been partially supported by the Spanish Ministerio de Economía y Competitividad under the personal grant agreement RYC-2015-01633. We acknowledge PRACE for awarding us ac-
cess to MareNostrum at Barcelona Supercomputing Center (BSC), Spain.
Peer Reviewed
Postprint (author's final draft)
20 p.
eng
Elsevier
Attribution-NonCommercial-NoDerivs 3.0 Spain
Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)
http://creativecommons.org/licenses/by-nc-nd/3.0/es/
https://creativecommons.org/licenses/by-nc-nd/4.0/
Open Access
Àrees temàtiques de la UPC::Informàtica::Aplicacions de la informàtica::Aplicacions informàtiques a la física i l‘enginyeria
Algorithm
Geometry
High-order mesh curving
Distributed parallel
Pre-conditioner
p-continuation
Simulació per ordinador
Automatic Penalty and Degree Continuation for Parallel Pre-Conditioned Mesh Curving on Virtual Geometry
Article
https://www.sciencedirect.com/science/article/pii/S0010448522000124
info:eu-repo/grantAgreement/EC/H2020/715546/EU/Best Curved Adapted Meshes for Space-Time Flow Simulations/Tesseract
103208
Computer-Aided Design
146
eprints
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3343942022-05-22T03:01:23Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Shen, Jingcheng
Ino, Fumihiko
Farrés Coma, Albert
Hanzich, Mauricio
Barcelona Supercomputing Center
2020-12-14T16:07:46Z
2020-12-14T16:07:46Z
2020-12-01
Shen, J. [et al.]. A data-centric directive-based framework to accelerate out-of-core stencil computation on a GPU. "EICE Transactions on Information and Systems", 1 Desembre 2020, vol. E103.D, núm. 12, p. 2421-2434.
0916-8532
1745-1361
http://hdl.handle.net/2117/334394
10.1587/transinf.2020PAP0014
Special Section on Parallel, Distributed, and Reconfigurable Computing, and Networking
Graphics processing units (GPUs) are highly efficient architectures for parallel stencil code; however, the small device (i.e., GPU) memory capacity (several tens of GBs) necessitates the use of out-of-core computation to process excess data. Great programming effort is needed to manually implement efficient out-of-core stencil code. To relieve such programming burdens, directive-based frameworks emerged, such as the pipelined accelerator (PACC); however, they usually lack specific optimizations to reduce data transfer. In this paper, we extend PACC with two data-centric optimizations to address data transfer problems. The first is a direct-mapping scheme that eliminates host (i.e., CPU) buffers, which intermediate between the original data and device buffers. The second is a region-sharing scheme that significantly reduces host-to-device data transfer. The extended PACC was applied to an acoustic wave propagator, automatically extending the length of original serial code 2.3-fold to obtain the out-of-core code. Experimental results revealed that on a Tesla V100 GPU, the generated code ran 41.0, 22.1, and 3.6 times as fast as implementations based on Open Multi-Processing (OpenMP), Unified Memory, and the previous PACC, respectively. The generated code also demonstrated usefulness with small datasets that fit in the device capacity, running 1.3 times as fast as an in-core implementation.
This study was supported in part by the Japan Society for the Promotion of Science KAKENHI Grant Numbers JP15H01687, JP16H02801, and JP20K21794.
Peer Reviewed
Postprint (published version)
eng
Institute of Electronics, Information and Communication Engineers
Àrees temàtiques de la UPC::Informàtica::Arquitectura de computadors::Arquitectures paral·leles
Data transmission systems
Graphics processing units
Stencil computation
Out-of-core computation
Data-centric optimizations
GPU
Unitats de processament gràfic
OpenMP (Interfície de programació d'aplicacions)
pipelined accelerator
A data-centric directive-based framework to accelerate out-of-core stencil computation on a GPU
Article
https://www.jstage.jst.go.jp/article/transinf/E103.D/12/E103.D_2020PAP0014/_article/-char/en
Open Access
EICE Transactions on Information and Systems
E103.D
12
2421
2434
eprints
oai:upcommons.upc.edu:2117/1904952022-05-15T00:28:15Zcom_2117_3911com_2117_28579com_2117_28577com_2117_115277com_2117_28581com_2117_80515com_2117_23714com_2117_28578com_2117_15797col_2117_3912col_2117_119980col_2117_80523col_2117_3055openAccess
Otero Calviño, Beatriz
Rojas, Otilio
Moya, Ferrán
Castillo, José
Universitat Politècnica de Catalunya. Departament d'Arquitectura de Computadors
Barcelona Supercomputing Center
Universitat Politècnica de Catalunya. VIRTUOS - Virtualisation and Operating Systems
2020-06-11T09:12:56Z
2022-05-15T00:28:15Z
2020-06-15
Otero, B. [et al.]. Alternating direction implicit time integrations for finite difference acoustic wave propagation: parallelization and convergence. "Computers and fluids", 15 Juny 2020, vol. 205, article 104584, p. 1-12.
0045-7930
http://arxiv.org/abs/2006.07583
http://hdl.handle.net/2117/190495
10.1016/j.compfluid.2020.104584
This work studies the parallelization and empirical convergence of two finite difference acoustic wave propagation methods on 2-D rectangular grids, that use the same alternating direction implicit (ADI) time integration. This ADI integration is based on a second-order implicit Crank-Nicolson temporal discretization that is factored out by a Peaceman-Rachford decomposition of the time and space equation terms. In space, these methods highly diverge and apply different fourth-order accurate differentiation techniques. The first method uses compact finite differences (CFD) on nodal meshes that requires solving tridiagonal linear systems along each grid line, while the second one employs staggered-grid mimetic finite differences (MFD). For each method, we implement three parallel versions: (i) a multithreaded code in Octave, (ii) a C++ code that exploits OpenMP loop parallelization, and (iii) a CUDA kernel for a NVIDIA GTX 960 Maxwell card. In these implementations, the main source of
parallelism is the simultaneous ADI updating of each wave field matrix, either column-wise or row-wise, according to the differentiation direction. In our numerical applications, the highest performances are displayed by the CFD and MFD CUDA codes that achieve speedups of 7.21x and 15.81x, respectively, relative to their C++ sequential counterparts with optimal compilation flags. Our test cases also allow to assess the numerical convergence and accuracy of both methods. In a problem with exact harmonic solution, both methods exhibit convergence rates close to 4 and the MDF accuracy is practically higher. Alternatively, both convergences decay to second order on smooth problems with severe gradients at boundaries, and the MDF rates degrade in highly-resolved grids leading to larger inaccuracies. This transition of empirical convergences agrees with the nominal truncation errors in space and time.
First author was partially supported by the Generalitat de Catalunya under agreement 2017-SGR-962 and the RIS3CAT DRAC project (001-P-001723). The research leading to these results has received funding from the European Union’s Horizon 2020 Programme, grant agreement No. 828947, and from the Mexican Department of Energy, CONACYT-SENER Hidrocarburos grant agreement No. B-S-69926. This project has also received funding from the European Union’s Horizon 2020research and innovation programme under the Marie Sklodowska-Curie grant agreement No 777778 (MATHROCKS). O. Rojas also thank the European Union’s Horizon 2020 Programme under the ChEESE Project, grant agreement no. 823844.
Peer Reviewed
Postprint (author's final draft)
12 p.
eng
Elsevier
Attribution-NonCommercial-NoDerivatives 4.0 International
©2020 Elsevier
https://creativecommons.org/licenses/by-nc-nd/4.0/
Open Access
Àrees temàtiques de la UPC::Enginyeria de la telecomunicació::Processament del senyal::Processament de la parla i del senyal acústic
Finite differences
Application program interfaces (Computer software)
Sound-waves
CUDA and OpenMP programming
ADI
Compact finite differences
Mimetic operators
Diferències finites
Interfícies de programació d'aplicacions (Programari)
Ones sonores
Alternating direction implicit time integrations for finite difference acoustic wave propagation: parallelization and convergence
Article
https://www.sciencedirect.com/science/article/pii/S0045793020301560
info:eu-repo/grantAgreement/EC/H2020/777778/EU/Multiscale Inversion of Porous Rock Physics using High-Performance Simulators: Bridging the Gap between Mathematics and Geophysics/MATHROCKS
info:eu-repo/grantAgreement/EC/H2020/823844/EU/Centre of Excellence for Exascale in Solid Earth/ChEESE
info:eu-repo/grantAgreement/EC/H2020/828947/EU/Supercomputing and Energy for Mexico/ENERXICO
28486179
Otero, B.; Rojas, O.; Moya, F.; Castillo, J.
Computers and fluids
205
article 104584
1
12
eprints
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/1165042020-07-23T23:27:51Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
ASDEX Upgrade Team
EUROfusion MST1 Team
Mantsinen, Mervi
Barcelona Supercomputing Center
2018-04-20T09:48:04Z
2018-04-20T09:48:04Z
2017-06-28
ASDEX Upgrade Team; EUROfusion MST1 Team; Mantsinen, M. Overview of ASDEX Upgrade results. "Nuclear Fusion", 28 Juny 2017, vol. 57, núm. 10.
0029-5515
http://hdl.handle.net/2117/116504
10.1088/1741-4326/aa64f6
The ASDEX Upgrade (AUG) programme is directed towards physics input to critical elements of the ITER design and the preparation of ITER operation, as well as addressing physics issues for a future DEMO design. Since 2015, AUG is equipped with a new pair of 3-strap ICRF antennas, which were designed for a reduction of tungsten release during ICRF operation. As predicted, a factor two reduction on the ICRF-induced W plasma content could be achieved by the reduction of the sheath voltage at the antenna limiters via the compensation of the image currents of the central and side straps in the antenna frame. There are two main operational scenario lines in AUG. Experiments with low collisionality, which comprise current drive, ELM mitigation/suppression and fast ion physics, are mainly done with freshly boronized walls to reduce the tungsten influx at these high edge temperature conditions. Full ELM suppression and non-inductive operation up to a plasma current of Ip = 0.8 MA could be obtained at low plasma density. Plasma exhaust is studied under conditions of high neutral divertor pressure and separatrix electron density, where a fresh boronization is not required. Substantial progress could be achieved for the understanding of the confinement degradation by strong D puffing and the improvement with nitrogen or carbon seeding. Inward/outward shifts of the electron density profile relative to the temperature profile effect the edge stability via the pressure profile changes and lead to improved/decreased pedestal performance. Seeding and D gas puffing are found to effect the core fueling via changes in a region of high density on the high field side (HFSHD). The integration of all above mentioned operational scenarios will be feasible and naturally obtained in a large device where the edge is more opaque for neutrals and higher plasma temperatures provide a lower collisionality. The combination of exhaust control with pellet fueling has been successfully demonstrated. High divertor enrichment values of nitrogen En > 10 have been obtained during pellet injection, which is a prerequisite for the simultaneous achievement of good core plasma purity and high divertor radiation levels. Impurity accumulation observed in the all-metal AUG device caused by the strong neoclassical inward transport of tungsten in the pedestal is expected to be relieved by the higher neoclassical temperature screening in larger devices.
This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014-2018
under grant agreement number 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission.
Peer Reviewed
Postprint (published version)
12 p.
eng
International Atomic Energy Agency (IAEA)
Attribution-NonCommercial-NoDerivs 3.0 Spain
http://creativecommons.org/licenses/by-nc-nd/3.0/es/
Open Access
Àrees temàtiques de la UPC::Energies
Fusion reactions
Nuclear fusion
Nuclear fusion
Tokamak physics
ITER
DEMO
Fusió nuclear
Overview of ASDEX Upgrade results
Article
http://iopscience.iop.org/article/10.1088/1741-4326/aa64f6/meta
info:eu-repo/grantAgreement/EC/H2020/633053/EU/Implementation of activities described in the Roadmap to Fusion during Horizon 2020 through a Joint programme of the members of the EUROfusion consortium/EUROfusion
Nuclear Fusion
57
10
eprints
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3728292023-01-01T03:46:09Zcom_2117_3911com_2117_28579com_2117_28577com_2117_3123com_2117_28581com_2117_184555com_2117_184544com_2117_80515com_2117_23714com_2117_28578com_2117_15797col_2117_3912col_2117_3124col_2117_184721col_2117_80523col_2117_3055openAccess
García Calatrava, Carlos
Becerra Fontal, Yolanda
Cucchietti, Fernando
Universitat Politècnica de Catalunya. Doctorat en Arquitectura de Computadors
Universitat Politècnica de Catalunya. Departament d'Arquitectura de Computadors
Barcelona Supercomputing Center
Universitat Politècnica de Catalunya. CAP - Grup de Computació d'Altes Prestacions
2022-09-15T08:07:21Z
2022-09-15T08:07:21Z
2022-08-18
Garcia, C.; Becerra, Y.; Cucchietti, F. A holistic scalability strategy for time series databases following cascading polyglot persistence. "Big data and cognitive computing", 18 Agost 2022, vol. 6, núm. 3, article 86, p. 1-30.
2504-2289
http://hdl.handle.net/2117/372829
10.3390/bdcc6030086
Time series databases aim to handle big amounts of data in a fast way, both when introducing new data to the system, and when retrieving it later on. However, depending on the scenario in which these databases participate, reducing the number of requested resources becomes a further requirement. Following this goal, NagareDB and its Cascading Polyglot Persistence approach were born. They were not just intended to provide a fast time series solution, but also to find a great cost-efficiency balance. However, although they provided outstanding results, they lacked a natural way of scaling out in a cluster fashion. Consequently, monolithic approaches could extract the maximum value from the solution but distributed ones had to rely on general scalability approaches. In this research, we proposed a holistic approach specially tailored for databases following Cascading Polyglot Persistence to further maximize its inherent resource-saving goals. The proposed approach reduced the cluster size by 33%, in a setup with just three ingestion nodes and up to 50% in a setup with 10 ingestion nodes. Moreover, the evaluation shows that our scaling method is able to provide efficient cluster growth, offering scalability speedups greater than 85% in comparison to a theoretically 100% perfect scaling, while also ensuring data safety via data replication.
This research was partly supported by the Grant Agreement No. 857191, by the Spanish Ministry of Science and Innovation (contract PID2019-107255GB) and by the Generalitat de Catalunya (contract 2017-SGR-1414).
Peer Reviewed
Postprint (published version)
30 p.
eng
Multidisciplinary Digital Publishing Institute (MDPI)
Attribution 4.0 International
http://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Informàtica::Sistemes d'informació::Emmagatzematge i recuperació de la informació
Time-series analysis -- Data processing
Time series database
Cascading polyglot persistence
Resource-saving approach
Data stream
MongoDB
Scalability
Cluster
Real time
Near real time
NagareDB
Series temporals -- Informàtica
A holistic scalability strategy for time series databases following cascading polyglot persistence
Article
https://www.mdpi.com/2504-2289/6/3/86
info:eu-repo/grantAgreement/EC/H2020/857191/EU/Distributed Digital Twins for industrial SMEs: a big-data platform/IoTwins
34224957
Garcia, C.; Becerra, Y.; Cucchietti, F.
Big data and cognitive computing
6
3, article 86
1
30
eprints
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3423592023-09-24T04:14:29Zcom_2117_79679com_2117_28579com_2117_28577com_2117_2072com_2117_28581com_2117_80515com_2117_23714com_2117_28578com_2117_15797col_2117_79694col_2117_6145col_2117_80523col_2117_3055openAccess
Costa Solé, Albert
Ruiz Gironès, Eloi
Sarrate Ramos, Josep
Universitat Politècnica de Catalunya. Departament d'Enginyeria Civil i Ambiental
Barcelona Supercomputing Center
Universitat Politècnica de Catalunya. LACÀN - Mètodes Numèrics en Ciències Aplicades i Enginyeria
2021-03-24T13:46:53Z
2022-03-06T01:28:26Z
2021-03-06
Costa, A.; Ruiz, E.; Sarrate, J. High-order hybridizable discontinuous Galerkin formulation for one-phase flow through porous media. "Journal of scientific computing", 6 Març 2021, vol. 87, article 29, p. 1-31.
0885-7474
http://hdl.handle.net/2117/342359
10.1007/s10915-021-01436-9
We present a stable high-order hybridizable discontinuous Galerkin (HDG) formulation coupled with high-order diagonal implicit Runge–Kuta (DIRK) schemes to simulate slightly compressible one-phase flow through porous media. The HDG stability depends on the selection of a single parameter and its definition is crucial to ensure the stability and to achieve the high-order properties of the method. Thus, we extend the work of Nguyen et al. in J Comput Phys 228, 8841–8855, 2009 to deduce an analytical expression for the stabilization parameter using the material parameters of the problem and the Engquist-Osher monotone flux scheme. The formulation is high-order accurate for the pressure, the flux and the velocity with the same convergence rate of P+1, being P the polynomial degree of the approximation. This is important because high-order methods have the potential to reduce the computational cost while obtaining more accurate solutions with less dissipation and dispersion errors than low order methods. The formulation can use unstructured meshes to capture the heterogeneous properties of the reservoir. In addition, it is conservative at the element level, which is important when solving PDE’s in conservative form. Moreover, a hybridization procedure can be applied to reduce the size of the global linear system. To keep these advantages, we use DIRK schemes to perform the time integration. DIRK schemes are high-order accurate and have a low memory footprint. We show numerical evidence of the optimal convergence rates obtained with the proposed formulation. Finally, we present several examples to illustrate the capabilities of the formulation.
This work has been supported by FEDER and the Spanish Government, Ministerio de Ciencia Innovación y Universidades grant project contract PGC2018-097257-B-C33 and Ministerio de Economía y Competitividad under grant BES-2015-072833.
Peer Reviewed
Postprint (author's final draft)
31 p.
eng
Àrees temàtiques de la UPC::Enginyeria civil::Materials i estructures
Àrees temàtiques de la UPC::Matemàtiques i estadística::Anàlisi numèrica::Mètodes numèrics
Numerical analysis
Porous materials
Runge-Kutta formulas
Galerkin methods
One-phase porous media flow
Slightly compressible
Hybridizable discontinuous Galerkin
High-order
Diagonally implicit Runge–Kutta
Anàlisi numèrica
Materials porosos
Runge-Kutta, Fórmules de
Galerkin, Mètodes de
High-order hybridizable discontinuous Galerkin formulation for one-phase flow through porous media
Article
https://link.springer.com/article/10.1007/s10915-021-01436-9
info:eu-repo/grantAgreement/AEI/Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020/PGC2018-097257-B-C33/ES/SIMULACION IN VIVO DEL EFECTO DE LA HIPOXIA Y LA DOSIS DEL FARMACO EN EL CRECIMIENTO DEL GLIOBLASTOMA/
info:eu-repo/grantAgreement/MINECO//CTM2014-55014-C3-3-R/ES/INTEGRACION DE NUEVAS METODOLOGIAS PARA LA PLANIFICACION Y ANALISIS MEDIOAMBIENTAL DE YACIMIENTOS PETROLIFEROS/
Open Access
30830174
Costa, A.; Ruiz, E.; Sarrate, J.
Journal of scientific computing
87
article 29
1
31
eprints
10.13039/501100011033
Agencia Estatal de Investigación
10.13039/501100003329
Ministerio de Economía y Competitividad
oai:upcommons.upc.edu:2117/869192022-05-17T10:08:38Zcom_2117_80515com_2117_23714com_2117_28578com_2117_28577col_2117_80523openAccess
Martín, Gonzalo
Singh, David E.
Marinescu, Maria-Cristina
Carretero, Jesús
Barcelona Supercomputing Center
2016-05-11T09:22:33Z
2017-08-01T00:30:34Z
2015-07
Martín, Gonzalo [et al.]. Enhancing the performance of malleable MPI applications by using performance-aware dynamic reconfiguration. "Parallel Computing", Juliol 2015, vol. 46, p. 60-77.
0167-8191
http://hdl.handle.net/2117/86919
10.1016/j.parco.2015.04.003
The work in this paper focuses on providing malleability to MPI applications by using a novel performance-aware dynamic reconfiguration technique. This paper describes the design and implementation of Flex-MPI, an MPI library extension which can automatically monitor and predict the performance of applications, balance and redistribute the workload, and reconfigure the application at runtime by changing the number of processes. Unlike existent approaches, our reconfiguring policy is guided by user-defined performance criteria. We focus on iterative SPMD programs, a class of applications with critical mass within the scientific community. Extensive experiments show that Flex-MPI can improve the performance, parallel efficiency, and cost-efficiency of MPI programs with a minimal effort from the programmer.
This work has been partially supported by the Spanish Ministry of Economy and Competitiveness under the project TIN2013-
41350-P, Scalable Data Management Techniques for High-End Computing Systems, and EU under the COST Program Action IC1305, Network for Sustainable Ultrascale Computing (NESUS)
Peer Reviewed
Postprint (author's final draft)
18 p.
eng
Elsevier
Attribution-NonCommercial-NoDerivs 4.0 International License
https://creativecommons.org/licenses/by-nc-nd/4.0/
Open Access
Àrees temàtiques de la UPC::Enginyeria electrònica
Distributed computing
Distributed systems
Malleable MPI applications
Performance-aware dynamic Reconfiguration
Computational prediction model
Distributed systems
High performance computing
Computació distribuïda
Enhancing the performance of malleable MPI applications by using performance-aware dynamic reconfiguration
Article
http://www.sciencedirect.com/science/article/pii/S0167819115000642
info:eu-repo/grantAgreement/MINECO//TIN2013-41350-P/ES/TECNICAS DE GESTION ESCALABLE DE DATOS PARA HIGH-END COMPUTING SYSTEMS/
Parallel Computing
46
60
77
eprints
10.13039/501100003329
Ministerio de Economía y Competitividad
oai:upcommons.upc.edu:2117/3755462023-09-17T03:38:00Zcom_2117_184560com_2117_184544com_2117_28577com_2117_80515com_2117_23714com_2117_28578com_2117_15797col_2117_184705col_2117_80523col_2117_3055openAccess
Oks, David
Samaniego Alvarado, Cristóbal
Houzeaux, Guillaume
Butakoff, Constantine
Vázquez, Mariano
Universitat Politècnica de Catalunya. Doctorat en Matemàtica Aplicada
Barcelona Supercomputing Center
2022-11-03T15:04:42Z
2022-11-03T15:04:42Z
2022-12
Oks, D. [et al.]. Fluid–structure interaction analysis of eccentricity and leaflet rigidity on thrombosis biomarkers in bioprosthetic aortic valve replacements. "The International journal for numerical methods in biomedical engineering", Desembre 2022, vol. 38, núm. 12, article e3649, p. 1-42.
2040-7939
http://hdl.handle.net/2117/375546
10.1002/cnm.3649
This work intends to study the effect of aortic annulus eccentricity and leaflet rigidity on the performance, thrombogenic risk and calcification risk in bioprosthetic aortic valve replacements (BAVRs). To address these questions, a two-way immersed fluid–structure interaction (FSI) computational model was implemented in a high-performance computing (HPC) multi-physics simulation software, and validated against a well-known FSI benchmark. The aortic valve bioprosthesis model is qualitatively contrasted against experimental data, showing good agreement in closed and open states. Regarding the performance of BAVRs, the model predicts that increasing eccentricities yield lower geometric orifice areas (GOAs) and higher normalized transvalvular pressure gradients (TPGs) for healthy cardiac outputs during systole, agreeing with in vitro experiments. Regions with peak values of residence time are observed to grow with eccentricity in the sinus of Valsalva, indicating an elevated risk of thrombus formation for eccentric configurations. In addition, the computational model is used to analyze the effect of varying leaflet rigidity on both performance, thrombogenic and calcification risks with applications to tissue-engineered prostheses. For more rigid leaflets it predicts an increase in systolic and diastolic TPGs, and decrease in systolic GOA, which translates to decreased valve performance. The peak shear rate and residence time regions increase with leaflet rigidity, but their volume-averaged values were not significantly affected. Peak solid stresses are also analyzed, and observed to increase with rigidity, elevating risk of valve calcification and structural failure. To the authors' knowledge this is the first computational FSI model to study the effect of eccentricity or leaflet rigidity on thrombogenic biomarkers, providing a novel tool to aid device manufacturers and clinical practitioners.
This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 713673. The research leading to these results has also received funding from “la Caixa” Foundation, with fellowship ID: LCF/BQ/DI18/11660044, and has been co-funded by the project CompBioMed2 (H2020-EU.1.4.1.3. Grant No. 823712)
Peer Reviewed
Postprint (published version)
42 p.
eng
John Wiley & sons
Attribution-NonCommercial-NoDerivatives 4.0 International
http://creativecommons.org/licenses/by-nc-nd/4.0/
Open Access
Àrees temàtiques de la UPC::Matemàtiques i estadística::Matemàtica aplicada a les ciències
Àrees temàtiques de la UPC::Enginyeria biomèdica
Aortic valve
Thrombosis
Computational fluid dynamics
Aortic valve replacement
Computational biomechanics
Fluid–structure interaction
Highperformance computing
Vàlvula aòrtica
Trombosi
Dinàmica de fluids computacional
Fluid–structure interaction analysis of eccentricity and leaflet rigidity on thrombosis biomarkers in bioprosthetic aortic valve replacements
Article
https://onlinelibrary.wiley.com/doi/10.1002/cnm.3649
info:eu-repo/grantAgreement/EC/H2020/823712/EU/A Centre of Excellence in Computational Biomedicine/CompBioMed2
info:eu-repo/grantAgreement/EC/H2020/713673/EU/Innovative doctoral programme for talented early-stage researchers in Spanish host organisations excellent in the areas of Science, Technology, Engineering and Mathematics (STEM)./INPhINIT
34844704
Oks, D.; Samaniego, C.; Houzeaux, G.; Butakoff, C.; Vázquez , M.
The International journal for numerical methods in biomedical engineering
38
12, e3649
1
42
eprints
10.13039/501100000780
European Commission
10.13039/501100000780
European Commission
oai:upcommons.upc.edu:2117/3697582023-01-01T03:57:16Zcom_2117_80516com_2117_23714com_2117_28578com_2117_28577com_2117_3911com_2117_28579com_2117_3123com_2117_28581com_2117_184555com_2117_184544com_2117_80515com_2117_15797col_2117_80530col_2117_3912col_2117_3124col_2117_184721col_2117_80523col_2117_3055openAccess
García Calatrava, Carlos
Becerra Fontal, Yolanda
Cucchietti, Fernando
Universitat Politècnica de Catalunya. Doctorat en Arquitectura de Computadors
Universitat Politècnica de Catalunya. Departament d'Arquitectura de Computadors
Barcelona Supercomputing Center
Universitat Politècnica de Catalunya. CAP - Grup de Computació d'Altes Prestacions
2022-07-07T08:40:39Z
2022-07-07T08:40:39Z
2022-06-30
Calatrava, C.G.; Becerra, Y.; Cucchietti, F.M. Introducing polyglot-based data-flow awareness to time-series data stores. "IEEE access", 30 Juny 2022, vol. 10, p. 69398-69411.
2169-3536
http://hdl.handle.net/2117/369758
10.1109/ACCESS.2022.3187405
The rising interest in extracting value from data has led to a broad proliferation of monitoring infrastructures, most notably composed by sensors, intended to collect this new oil. Thus, gathering data has become fundamental for a great number of applications, such as predictive maintenance techniques or anomaly detection algorithms. However, before data can be refined into insights and knowledge, it has to be efficiently stored and prepared for its later retrieval. As a consequence of this sensor and IoT boom, Time-Series databases (TSDB), designed to manage sensor data, became the fastest-growing database category since 2019. Here we propose a holistic approach intended to improve TSDB’s performance and efficiency. More precisely, we introduce and evaluate a novel polyglot-based approximation, aimed to tailor the data store, not only to time-series data –as it is done conventionally– but also to the data flow itself: From its ingestion, until its retrieval. In order to evaluate the approach, we materialize it in an alternative implementation of NagareDB, a resource-efficient time-series database, based on MongoDB, in turn, the most popular NoSQL storage solution. After implementing our approach into the database, we observe a global speed up, solving queries up to 12 times faster than MongoDB’s recently launched Time-series capability, as well as generally outperforming InfluxDB, the most popular time-series database. Our polyglot-based data-flow aware solution can ingest data more than two times faster than MongoDB, InfluxDB, and NagareDB’s original implementation, while using the same disk space as InfluxDB, and half of the requested by MongoDB.
This research was partly supported by the Spanish Ministry of Science and Innovation (contract PID2019-107255GB) and by the Generalitat de Catalunya (contract 2017-SGR-1414).
Peer Reviewed
Postprint (published version)
15 p.
eng
Institute of Electrical and Electronics Engineers (IEEE)
Attribution 4.0 International
http://creativecommons.org/licenses/by/4.0/
Open Access
Àrees temàtiques de la UPC::Informàtica::Arquitectura de computadors
Real-time data processing
Time-series analysis
Query languages (Computer science)
Cascading polyglot persistence
Data-flow awareness
Data cascade
Data store
Data stream
MongoDB
Multi-model database
NagareDB
Time-series database
Temps real (Informàtica)
Series temporals -- Anàlisi
Llenguatges d'interrogació (Informàtica)
Introducing polyglot-based data-flow awareness to time-series data stores
Article
https://ieeexplore.ieee.org/document/9810936
34002552
Calatrava, C.G.; Becerra, Y.; Cucchietti, F.M.
IEEE access
10
69398
69411
eprints
dim///col_2117_80523/100