DSpace Collection:
http://hdl.handle.net/2117/3920
2014-07-24T18:07:15ZEstructuras A-infinito en la opérada de cactus
http://hdl.handle.net/2117/22097
Title: Estructuras A-infinito en la opérada de cactus
Authors: Gálvez Carrillo, Maria Immaculada; Lombardi, Leandro; Tonks, Andrew
Abstract: Diversas versiones de la opérada de cactus inicialmente definida por Voronov han sido estudiadas. Es conocida su equivalencia débil con la opérada de pequeños discos. Se conoce pues que la opérada de cactus admite una acción de la opérada de Gerstenhaber salvo homotopía. En este proyecto, nuestro objetivo es obtener una realización explícita de dicha acción. Por el momento, hemos construido una acción explícita de la opérada A8 en la opérada de cactus, que presentamos en este pósterDiscrete-time static output-feedback H-infinity controller design for vehicle suspensions
http://hdl.handle.net/2117/23579
Title: Discrete-time static output-feedback H-infinity controller design for vehicle suspensions
Authors: Palacios Quiñonero, Francisco; Rubió Massegú, Josep; Rossell Garriga, Josep Maria; Karimi, Hamid Reza
Abstract: This paper provides a direct and practical presentation of a novel methodology for static output feedback controller design. The proposed design strategy has been successfully applied in the fields of control systems for seismic protection of large
buildings and multi-building structures, control of offshore wind
turbines, and active control of vehicle suspensions. The positive
results obtained in these initial applications clearly indicate that
this approach could be an effective tool in a large variety of
control problems, for which an LMI formulation of the statefeedback
version of the problem is available. The main objective
of the paper is to facilitate a brief and friendly presentation of the
main ideas involved in the new design methodology. To this end,
a discrete-time static output-feedback H1 controller is designed
for a simplified quarter-car suspension system. Numerical simulations
indicate that the proposed controller exhibits a remarkably
good behavior when compared with the corresponding statefeedback
H1 controller.2014-07-21T11:46:38ZEl e-portafolio del estudiante en Mahara-Moodle y Google Sites
http://hdl.handle.net/2117/23534
Title: El e-portafolio del estudiante en Mahara-Moodle y Google Sites
Authors: García Planas, María Isabel; Taberna Torres, Judit
Abstract: Es bien conocido el potencial que tiene el uso del e-portfolio del estudiante para hacer visible tanto para el mismo como para los demás, de cómo y hasta que nivel ha logrado sus objetivos.
Para realizar un e-portafolio se pueden utilizar distintas aplicaciones, entre ellas se encuentran Google Sites y Mahara.
Google Sites permite de forma sencilla editando una plantilla previamente preparada por el profesor, crear una página web como muestra de sus trabajos desarrollados a lo largo de sus estudios.
Mahara es un sistema de e-portafolio que puede conectarse a Moodle y el cual puede ser controlado por el estudiante y puede ser visible por el grupo. Debido a la interoperabilidad de Mahara especialmente con Moodle, este permite que desde la plataforma de Atenea se puedan interconectar el profesorado con el e-portafolio del estudiante.
En este trabajo presentamos los resultados obtenidos desde el año 2011 hasta la actualidad en las investigaciones realizadas sobre el e-portafolio en el marco de la Universidad Politècnica de Catalunya.2014-07-17T07:51:51ZRobust H2 static output feedback to control an autmomotive throttle valve
http://hdl.handle.net/2117/23431
Title: Robust H2 static output feedback to control an autmomotive throttle valve
Authors: Vargas, Alessandro; Acho Zuppa, Leonardo; Pujol Vázquez, Gisela; Oliveira, Ricardo C.L.F.; do Val, Joao B.R.; Peres, Pedro L.D.
Abstract: The paper presents a control strategy for an automotive electronic throttle body, a device largely used into vehicles to increase the efficiency of the combustion engines. The synthesis of the proposed controller is based on a linear matrix inequality (LMI) formulation, which allows us to deal with uncertainties on the measurements of the position of the throttle valve. The LMI approach generates a suboptimal solution for the robust H-2 static output feedback control problem, and the corresponding suboptimal control gain was evaluated in practice to control the valve position of the throttle. The usefulness of the approach has been verified not only by numerical simulations but also by real experiments taken in a laboratory prototype.2014-07-08T11:47:52ZUsing GF in multimodal assistants for mathematics
http://hdl.handle.net/2117/23341
Title: Using GF in multimodal assistants for mathematics
Authors: Archambault, Dominique; Caprotti, Olga; Ranta, Aarne; Saludes Closa, Jordi
Abstract: In this paper we present an ongoing effort in the computational linguistic field to develop multilingual
assistive technologies for mathematics. The approach is based on the Grammatical Framework used
in combination with UMCL and semantic encodings of mathematics like OpenMath and MathML3.
We review the formats for supporting alternative modalities of presentation of mathematics in order
to evaluate the effectiveness of the proposed approach. Finally we describe a very initial prototype
built using off-the-shelf speech synthesis to interface to the Sage suite of computer algebra systems.2014-07-01T08:10:14ZColored spanning graphs for set visualization
http://hdl.handle.net/2117/23314
Title: Colored spanning graphs for set visualization
Authors: Hurtado Díaz, Fernando Alfredo; Korman Cozzetti, Matias; Van Kreveld, Matias; Löffler, Maarten; Sacristán Adinolfi, Vera; Silveira, Rodrigo Ignacio; Speckmann, Bettina
Abstract: We study an algorithmic problem that is motivated by ink minimization for sparse set visualizations. Our input is a set of points in the plane which are either blue, red, or purple. Blue points belong exclusively to the blue set, red
points belong exclusively to the red set, and purple points belong to both sets.
A red-blue-purple spanning graph (RBP spanning graph) is a set of edges connecting the points such that the subgraph induced by the red and purple points is connected, and the subgraph induced by the blue and purple points is connected.
We study the geometric properties of minimum RBP spanning graphs and the algorithmic problems associated with computing them. Specifically, we show that the general problem is NP-hard. Hence we give an (1/2¿+1)-approximation, where ¿ is the Steiner ratio. We also present efficient exact solutions if the points are located on a line or a circle. Finally we consider extensions to more than two sets.2014-06-26T17:02:39ZClass talk: recurs en línia per a l'ensenyament d'assignatures en anglès
http://hdl.handle.net/2117/23190
Title: Class talk: recurs en línia per a l'ensenyament d'assignatures en anglès
Authors: Fortuny Santos, Jordi; Alsina Aubach, Montserrat2014-06-09T15:20:04ZGestió de projectes experimentals al laboratori
http://hdl.handle.net/2117/23164
Title: Gestió de projectes experimentals al laboratori
Authors: Graells Sobré, Moisès; Pérez Moya, Montserrat; Bernal, Fernando; Boada Altarriba, Enric; Borràs Cristòfol, Núria; Calvet Tarragona, Aureli; Carral Mahia, Eva Mª; Dosta Parcerisa, Jordi; Espuña Camarasa, Antonio; López Mesas, Montserrat; Miguel Gisbert, Leopoldo de; Pujol, Carme; Sánchez, Margarita; Valle Mendoza, Luis Javier del; Capon Garcia, Elisabeth; Nadal Cabezas, Sergi; Pérez, Mar; Yélamos, Ignacio; Bello, M. Camino; Ortega, Esther; San Antonio, Virginia2014-06-05T12:08:31ZData validation and reconstruction of flowmeters to provide the annual efficiency of ATLL transport water network in Catalonia
http://hdl.handle.net/2117/23093
Title: Data validation and reconstruction of flowmeters to provide the annual efficiency of ATLL transport water network in Catalonia
Authors: Quevedo Casín, Joseba Jokin; Pascual Pañach, Josep; Puig Cayuela, Vicenç; Saludes Closa, Jordi; Espin, S; Roquet, J
Abstract: The purpose of this paper is to provide a data validation/reconstruction of flowmeters that allow to determine the annual economic and hydraulic efficiency of the water transport network of Aigües Ter Llobregat (ATLL) Company corresponding to the 80% of the overall water transport network in Catalonia (Spain). The economic/hydraulic network efficiency is based on the daily data set collected by ATLL using about 200 flowmeters of the network. The data collected using these sensors are used by the remote control and information storage systems and it is stored in a relational database. All the information provided by ATLL is analyzed to detect inconsistent data using an automatic data validation method deployed in parallel with the evaluation of the network efficiency. As result of the validation process, corrections of flow measurements and of the volume of billed water are introduced. The results of the water transport network of ATLL obtained during the year 2010 will be used to illustrate the approach proposed in this paper.2014-05-29T10:45:01ZNonlinear reset integrator control design: Application to the active suspension control of vehicles
http://hdl.handle.net/2117/23092
Title: Nonlinear reset integrator control design: Application to the active suspension control of vehicles
Authors: Acho Zuppa, Leonardo
Abstract: We present an unexampled reset integrator control design based on the Clegg integrator system. Using an appropriate mathematical model of our Clegg integrator controller, stability proof of the closed-loop system applied to the vibration control problem of a second-order system is shown without invoking hybrid system theory. Furthermore, we illustrate the pplicability of our controller, from the numerical experiment point of view, to the suspension vibration control of vehicles.2014-05-29T09:15:56ZComparison of the occupational hazards in the Spanish mining sector based on the type of workplace in the period 2003-2012
http://hdl.handle.net/2117/23067
Title: Comparison of the occupational hazards in the Spanish mining sector based on the type of workplace in the period 2003-2012
Authors: Sanmiquel Pera, Lluís; Freijo Álvarez, Modesto; Rossell Garriga, Josep Maria; Bascompta Massanés, Marc
Abstract: Methods and background: This review has done a comparison of the 3 types of workplace in the Spanish mining sector. The 3 workplaces considered are: mines, quarries and mineral processing plants. The 10 most frequent accidents and deviations have been obtained for each one. It has also been calculated the annual incidence, frequency, average duration and severity indexes as well as the risk index for each one. Besides, the accident distribution has been modelling, based on exponential distribution function of the lost days in the 3 workplaces mentioned. Results: The main sort of accident is due to physical overexertion and the principal deviation is the material collapsing from the roof of the mines, no coordinate movements in quarries and body movements because of physical overexertion in mineral processing plants.2014-05-28T08:20:11ZPedro Padilla and his Mathematical Course (1753-1756): views on mixed mathematics in eighteenth-century Spain
http://hdl.handle.net/2117/23002
Title: Pedro Padilla and his Mathematical Course (1753-1756): views on mixed mathematics in eighteenth-century Spain
Authors: Blanco Abellán, Mónica; Puig Pla, Carles
Abstract: In 1717 the King Philip V established the Royal Guards Headquarters (Cuartel de
Guardias de Corps), mirroring the French garde du corps du roi. Intended mainly for
noblemen, it was an elitist institution, all its members having the rank of officers and
benefitting from huge privileges. Towards the end of 1750 an Academy of
Mathematics (Academia de Matemáticas) was created within the Royal Guards
Headquarters, under the direction of Captain Pedro Padilla (1724-1807?). This
academy was ruled by the same regulations as the Military Academy of Mathematics
of Barcelona (1720-1803).1 Attendance was not mandatory; it was only devised for
those interested in getting a deeper mathematical knowledge. In fact, rather than its
real practical use for the Royal Guards, mathematics was studied as a mark of
prestige as Hidalgo (1991) pointed out.2014-05-15T15:57:03ZA set simulation approach to the computation of invariant sets for nonlinear systems
http://hdl.handle.net/2117/22896
Title: A set simulation approach to the computation of invariant sets for nonlinear systems
Authors: Cugueró Escofet, Josep; Saludes Closa, Jordi; Escobet Canal, Teresa
Abstract: Given a nonlinear discrete-time system, previous works exist that compute invariant sets as finite unions of boxes. Set inversion algorithms based on interval arithmetic are used to obtain inner approximations of the one step set starting in an invariant target set. In this paper a complementary approach based on set simulation is proposed. An invariant set can be obtained if a set trajectory that initiates in a given set, reaches this set again in a given number of steps at most. The first advantage of the proposed method is that there is no need to know an initial invariant set. The second one is that for a given system, a high convergence rate of the trajectories tends to reduce the computational effort of the method. The main disadvantage is that the algorithm does not guarantee that an invariant set is obtained. It just guarantees a response in finite time.2014-05-07T16:11:31ZModeling and simulation of conducting crack propagation in ferroelectric single crystals under purely electrical loading
http://hdl.handle.net/2117/22836
Title: Modeling and simulation of conducting crack propagation in ferroelectric single crystals under purely electrical loading
Authors: Abdollahi Hosnijeh, Amir; Arias Vicente, Irene
Abstract: We present a phase-field model of fracture in ferroelectric single crystals for the simulation of conducting crack propagation under purely electrical loading. This is done by introducing the electrical enthalpy of a diffuse conducting layer into the phase-field formulation. Simulation results show an oblique crack propagation and crack branching from a conducting notch in a ferroelectric sample under applied electric fields. Microstructure evolution indicates the formation of 90 domains which results in a charge accumulation around the crack. The charge accumulation, in turn, induces a high electric field and hence a high electrostatic energy for driving the conducting crack.2014-05-06T08:29:39ZStabbing simplices of point sets with k-flats
http://hdl.handle.net/2117/22736
Title: Stabbing simplices of point sets with k-flats
Authors: Cano, Javier; Hurtado Díaz, Fernando Alfredo; Urrutia Galicia, Jorge
Abstract: Let S be a set of n points inRdin general position.A set H of k-flats is called an mk-stabber of S if the relative interior of anym-simplex with vertices in S is intersected by at least one element of H. In thispaper we give lower and upper bounds on the size of mínimum mk-stabbers of point sets in Rd. We study mainly mk-stabbers in the plane and in R32014-04-28T16:17:42Z