Ara es mostren els items 1925-1944 de 93814

  • A finite deformation membrane based on inter-atomic potentials for the transverse mechanics of nanotubes 

    Arroyo Balaguer, Marino; Belytschko, T. (2003-03)
    Article
    Accés obert
    A finite deformation hyper-elastic membrane theory based on inter-atomic potentials for crystalline films composed of a single atomic layer is developed. For this purpose, an extension of the standard Born rule that exploits ...
  • A finite difference based tool for analysing ground source heat pump system 

    Bag, Ramakrishna; Sedighi, Majid; Manju; Rhys Thomas, Hywel (Universitat Politècnica de Catalunya. Departament d'Enginyeria del Terreny, Cartogràfica i Geofísica, 2015-06-02)
    Text en actes de congrés
    Accés obert
    The ground heat exchangers (GHE) consist of pipes buried in the soil and are used for transferring heat between the soil and the heat exchanger pipes of the ground source heat pump (GSHP). This paper presents the development ...
  • A finite element approach to the simulation of hydraulic fractures with lag 

    Hunsweck, Michael J.; Shen, Yongxing; Lew, Adrian J. (2013)
    Article
    Accés obert
    We presented a finite-element-based algorithm to simulate plane-strain, straight hydraulic fractures in an impermeable elastic medium. The algorithm acCOllllts for the nonlinear coupling between the fluid pressure and the ...
  • A Finite Element Model for Free Surface and Two Fluid Flows on Fixed Meshes 

    Coppola Owen, Herbert (Universitat Politècnica de Catalunya, 2009-06-19)
    Tesi
    Accés obert
    Los flujos con interfaces móviles (problemas de superficie libres y de dos fluidos) aparecen en numerosas aplicaciones de ingeniería. Los métodos presentados en esta tesis están orientados principalmente a la simulación ...
  • A finite Element model for incompressible flow problems 

    Codina, Ramon (Universitat Politècnica de Catalunya, 1992-06-30)
    Tesi
    Accés obert
  • A finite element strategy coupling a gradient-enhanced damage model and cohesive cracks for quasi-brittle materials 

    Tamayo Mas, Elena; Rodríguez Ferran, Antonio (2013)
    Text en actes de congrés
    Accés restringit per política de l'editorial
    A new combined strategy to describe failure of quasi-brittle materials is presented thus allowing the complete description of the process, from initiation of damage to crack propagation. For the early stages of the process, ...
  • A finite point method for adaptive-three-dimensional compressible flow calculations 

    Ortega, Enrique; Oñate Ibáñez de Navarra, Eugenio; Idelsohn Barg, Sergio Rodolfo (2009-07-30)
    Article
    Accés obert
    The finite point method (FPM) is a meshless technique, which is based on both, a weighted least-squares numerical approximation on local clouds of points and a collocation technique which allows obtaining the discrete ...
  • A finite thickness band method for ductile fracture analysis 

    Huespe, Alfredo Edmundo; Needleman, Alan; Oliver Olivella, Xavier; Sánchez, Pedro José (2009)
    Article
    Accés obert
    We present a finite element method with a finite thickness embedded weak discontinuity to analyze ductile fracture problems. The formulation is restricted to small geometry changes. The material response is characterized ...
  • A finite-volume/level-set interface capturing method for unstructured grids: Simulations of bubbles rising through viscous liquids 

    Balcázar Arciniega, Néstor; Jofre Cruanyes, Lluís; Lehmkuhl Barba, Oriol; Rigola Serrano, Joaquim; Castro González, Jesús; Oliva Llena, Asensio (WIT Press, 2014)
    Text en actes de congrés
    Accés obert
    A numerical method is developed for simulating two-phase flows with moving inter-phase boundaries, which is integrated in a finite-volume framework on collocated unstructured grids of arbitrary element type. The location, ...
  • A finite-volume/level-set method for simulating two-phase flows on unstructured grids 

    Balcázar Arciniega, Néstor; Jofre Cruanyes, Lluís; Lehmkuhl Barba, Oriol; Castro González, Jesús; Rigola Serrano, Joaquim (2014-09)
    Article
    Accés restringit per política de l'editorial
    The conservative level-set method for capturing the interface between two fluids is combined with a variable density projection scheme to simulate incompressible two-phase flows on unstructured meshes. All equations are ...
  • A First approach of using ultrasound as an alternative for blanching in vacuum-packaged potato strips 

    Alvares Amaral, Rivia; Benedetti, Benedito Carlo; Pujolà Cunill, Montserrat; Achaerandio Puente, María Isabel; Bachelli, Mara Lígia (2016-10-01)
    Article
    Accés restringit per política de l'editorial
    The effect of ultrasound (US) (40 kHz, 200 W, 3 min), blanching (85 °C, 3.5 min), and the combination of both methods was evaluated on the quality of vacuum-packaged potato strips stored at 3 ± 1 °C for up to 10 days. For ...
  • A first approach to the multipurpose relational database server 

    Blanco, Ignacio J.; Martínez-Cruz, Carmen; Serrano Chica, José María; Vila Miranda, María Amparo (Universitat Politècnica de Catalunya. Secció de Matemàtiques i Informàtica, 2005)
    Article
    Accés obert
    In this paper, an architecture and an implementation of a multipurpose relational database server are proposed. This architecture enables classical queries to be executed, deductions to be made, and data mining operations to ...
  • A first approximation in order to define a Difficulty Factor of the bi-classification in a dataset by using SVMs 

    González Abril, Luis; Angulo Bahón, Cecilio (2013)
    Comunicació de congrés
    Accés obert
    The main aim in this paper is to analyze the complexity of a Support Vector Machine -SVM- in the construction of a classifier for a bi-classification problem on a specific dataset. Hence, an index is defined in terms of ...
  • A first principle analysis of the structure of oligoanilines doped with alkylsulfonic acids 

    Casanovas, Jordi; Canales Gabriel, Manel; Ferreira, Carlos; Alemán Llansó, Carlos (2009)
    Article
    Accés restringit per política de l'editorial
    The interaction of polyaniline with alkylsulfonate dopants have been investigated at the atomic level using quantum mechanical methods. Calculations have been performed on complexes formed by dopant molecules with an alkyl ...
  • A first study on an oscillatory flow enclosed in a finite cylinder 

    Panadès i Guinart, Carles (Universitat Politècnica de Catalunya, 2009-09-14)
    Projecte Final de Màster Oficial
    Accés obert
    In this preliminar work, an oscillatory flow contained in a closed cylinder is investigated by means of spectral methods. The problem is quite related with the Stokes boundary layer and the major phenomena belong to this ...
  • A fittingness factor-based spectrum management framework for cognitive radio networks 

    Bouali, Faouzi; Sallent Roig, José Oriol; Pérez Romero, Jordi; Agustí Comes, Ramon (2013-03)
    Article
    Accés restringit per política de l'editorial
    In order to increase cognitive radios (CRs) operation efficiency, there has been an increasing interest in strengthening awareness level about spectrum utilisation. In this respect, this paper proposes to exploit the ...
  • A fix-and-relax heuristic for controlled tabular adjustment 

    Baena, Daniel; Castro Pérez, Jordi (2013-07)
    Report de recerca
    Accés obert
    Controlled tabular adjustment (CTA) is an emerging protect ion technique for tabular data pro- tection. CTA formulates a mixed integer linear programming problem, which is tough for tables of moderate size. Finding a ...
  • A Fixed-Frequency Quasi-Sliding Control Algorithm: Application to Power Inverters Design by Means of FPGA Implementation 

    Ramos Lara, Rafael Ramón; Biel Solé, Domingo; Fossas Colet, Enric; Guinjoan Gispert, Francisco (Institute of Electrical and Electronics Engineers (IEEE), 2003-01-31)
    Article
    Accés obert
    In this paper a fixed-frequency quasi-sliding control algorithm based on switching surface zero averaged dynamics (ZAD) is reported. This algorithm is applied to the design of a Buck-based inverter, and implemented in a ...
  • A flatness-based generalized optimization approach to spectral estimation 

    Nadeu Camprubí, Climent; Bertran Salvans, Miguel (1990-04)
    Article
    Accés obert
    In the optimization formulation, once the known autocorrelations are fixed as constraints, the objective functional completely characterizes the corresponding method of spectral estimation. After observing that this ...
  • A flexible dialogue system for enhancing web usability 

    Gatius Vila, Marta; González Bermúdez, Meritxell (WWW2009, 2009)
    Comunicació de congrés
    Accés restringit per política de l'editorial
    In this paper, we study how the performance and usability of web dialogue systems could be enhanced by using an appropriate representation of the different types of knowledge involved in communication: general dialogue ...