Ponències/Comunicacions de congressos
http://hdl.handle.net/2117/3920
2017-01-23T08:51:53ZObstacle detection and avoidance system for Guanay II AUV
http://hdl.handle.net/2117/99642
Obstacle detection and avoidance system for Guanay II AUV
Galarza Bogotá, Cesar Mauricio; Masmitjà Rusiñol, Ivan; Prat Tasias, Jordi; Trullols Farreny, Enric; Gomáriz Castro, Spartacus
2017-01-18T17:03:25ZGalarza Bogotá, Cesar MauricioMasmitjà Rusiñol, IvanPrat Tasias, JordiTrullols Farreny, EnricGomáriz Castro, SpartacusMatriz Laplaciana de grafos ponderados con vértices independientes
http://hdl.handle.net/2117/99486
Matriz Laplaciana de grafos ponderados con vértices independientes
Gago Álvarez, Silvia
2017-01-17T13:55:03ZGago Álvarez, SilviaOn the set of periods of the 2-periodic Lyness' equation
http://hdl.handle.net/2117/99190
On the set of periods of the 2-periodic Lyness' equation
Bastien, Guy; Mañosa Fernández, Víctor; Rogalski, Marc
We study the periodic solutions of the non-autonomous periodic Lyness’ recurrence un+2=(an+un+1)/un, where {an}n is a cycle with positive values a,b and with positive initial conditions. Among other methodological issues we give an outline of the proof of the following results: (1) If (a,b)¿(1,1), then there exists a value p0(a,b) such that for any p>p0(a,b) there exist continua of initial conditions giving rise to 2p-periodic sequences. (2) The set of minimal periods arising when (a,b)¿(0,8)2 and positive initial conditions are considered, contains all the even numbers except 4, 6, 8, 12 and 20. If a¿b, then it does not appear any odd period, except 1.
The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-662-52927-0_22
2017-01-13T09:24:26ZBastien, GuyMañosa Fernández, VíctorRogalski, MarcWe study the periodic solutions of the non-autonomous periodic Lyness’ recurrence un+2=(an+un+1)/un, where {an}n is a cycle with positive values a,b and with positive initial conditions. Among other methodological issues we give an outline of the proof of the following results: (1) If (a,b)¿(1,1), then there exists a value p0(a,b) such that for any p>p0(a,b) there exist continua of initial conditions giving rise to 2p-periodic sequences. (2) The set of minimal periods arising when (a,b)¿(0,8)2 and positive initial conditions are considered, contains all the even numbers except 4, 6, 8, 12 and 20. If a¿b, then it does not appear any odd period, except 1.Novel results on decentralized H-infinity controller design for structural vibration control of large buildings
http://hdl.handle.net/2117/98974
Novel results on decentralized H-infinity controller design for structural vibration control of large buildings
Palacios Quiñonero, Francisco; Rubió Massegú, Josep; Rossell Garriga, Josep Maria; Karimi, Hamid Reza
In this paper, we present a novel control design methodology for structural vibration control of large buildings. The main idea consists in decomposing the overall building system into decoupled single-story subsystems and modeling the subsystem interactions as external disturbances. Then, a complete set of local decentralized controllers can be efficiently computed using the existing LMI solvers. In the proposed approach, two different levels of decentralization can be distinguished: decentralized design and decentralized implementation, which are both of critical importance in large-scale control problems. From the design point of view, the local controllers are independently synthesized using only the low-dimensional subsystem models. The implementation phase is through the overall decentralized controller defined by the set of local controllers, which can drive the actuation devices using only local state-feedback information. To illustrate the proposed methodology, decentralized H8 controllers are designed for the seismic protection of a five-story building and a twenty-story building. A proper set of numerical simulations is carried out to demonstrate the effectiveness of the proposed decentralized controllers and the computation times are considered to assess the computational effectiveness of the decentralized design methodology.
2017-01-10T15:52:43ZPalacios Quiñonero, FranciscoRubió Massegú, JosepRossell Garriga, Josep MariaKarimi, Hamid RezaIn this paper, we present a novel control design methodology for structural vibration control of large buildings. The main idea consists in decomposing the overall building system into decoupled single-story subsystems and modeling the subsystem interactions as external disturbances. Then, a complete set of local decentralized controllers can be efficiently computed using the existing LMI solvers. In the proposed approach, two different levels of decentralization can be distinguished: decentralized design and decentralized implementation, which are both of critical importance in large-scale control problems. From the design point of view, the local controllers are independently synthesized using only the low-dimensional subsystem models. The implementation phase is through the overall decentralized controller defined by the set of local controllers, which can drive the actuation devices using only local state-feedback information. To illustrate the proposed methodology, decentralized H8 controllers are designed for the seismic protection of a five-story building and a twenty-story building. A proper set of numerical simulations is carried out to demonstrate the effectiveness of the proposed decentralized controllers and the computation times are considered to assess the computational effectiveness of the decentralized design methodology.Computational effectiveness of LMI design strategies for vibration control of large structures
http://hdl.handle.net/2117/98633
Computational effectiveness of LMI design strategies for vibration control of large structures
Palacios Quiñonero, Francisco; Rubió Massegú, Josep; Rossell Garriga, Josep Maria; Karimi, Hamid Reza
Distributed control systems for vibration control of large structures involve a large number of actuation devices and sensors that work coordinately to produce the desired control actions. Design strategies based on linear matrix inequality (LMI) formulations allow obtaining controllers for these complex control problems, which are characterized by large dimensionality, high computational cost and severe information constraints. In this paper, we conduct a comparative study of the computational effectiveness of three different LMI-based controller design strategies: H-infinity, energy-to-peak and energy-to-componentwise-peak. The H-infinity approach is a well-known design methodology and has been widely used in the literature. The
energy-to-peak approach is a particular case of generalized H2 design that is gaining a growing relevance in structural vibration control. Finally, the energy-to-componentwise-peak approach is a less common case of generalized H2 design that produces promising results among the three considered approaches. These controller design strategies are applied to synthesize active state-feedback controllers for the seismic protection of a five-story building and a twenty-story building both equipped with complete systems of interstory actuation devices. To evaluate the computational effectiveness of the proposed LMI design methodologies, the corresponding
computation times are compared and a suitable set of numerical simulations is carried out to assess the performance of the obtained controllers. As positive results, two main facts can be highlighted: the computational effectiveness of the energy-to-peak control design strategy
and the particularly well-balanced behavior exhibited by the energy-to-componentwise-peak controllers. On the negative side, it has to be mentioned the computational inefficiency of the considered LMI design methodologies to properly deal with very-large-scale control problems.
2016-12-20T14:30:19ZPalacios Quiñonero, FranciscoRubió Massegú, JosepRossell Garriga, Josep MariaKarimi, Hamid RezaDistributed control systems for vibration control of large structures involve a large number of actuation devices and sensors that work coordinately to produce the desired control actions. Design strategies based on linear matrix inequality (LMI) formulations allow obtaining controllers for these complex control problems, which are characterized by large dimensionality, high computational cost and severe information constraints. In this paper, we conduct a comparative study of the computational effectiveness of three different LMI-based controller design strategies: H-infinity, energy-to-peak and energy-to-componentwise-peak. The H-infinity approach is a well-known design methodology and has been widely used in the literature. The
energy-to-peak approach is a particular case of generalized H2 design that is gaining a growing relevance in structural vibration control. Finally, the energy-to-componentwise-peak approach is a less common case of generalized H2 design that produces promising results among the three considered approaches. These controller design strategies are applied to synthesize active state-feedback controllers for the seismic protection of a five-story building and a twenty-story building both equipped with complete systems of interstory actuation devices. To evaluate the computational effectiveness of the proposed LMI design methodologies, the corresponding
computation times are compared and a suitable set of numerical simulations is carried out to assess the performance of the obtained controllers. As positive results, two main facts can be highlighted: the computational effectiveness of the energy-to-peak control design strategy
and the particularly well-balanced behavior exhibited by the energy-to-componentwise-peak controllers. On the negative side, it has to be mentioned the computational inefficiency of the considered LMI design methodologies to properly deal with very-large-scale control problems.A new method for the identification of the parameters of the Dahl model
http://hdl.handle.net/2117/98340
A new method for the identification of the parameters of the Dahl model
García Baños, Isabel; Ikhouane, Fayçal
2016-12-15T13:43:54ZGarcía Baños, IsabelIkhouane, FayçalTexture analysis for wind turbine fault detection
http://hdl.handle.net/2117/98002
Texture analysis for wind turbine fault detection
Mujica Delgado, Luis Eduardo; Ruiz Ordóñez, Magda; Acho Zuppa, Leonardo; Alférez Baquero, Edwin Santiago; Tutivén Gálvez, Christian; Vidal Seguí, Yolanda; Rodellar Benedé, José
The future of wind energy industry passes through the use of larger and more flexible wind turbines in remote locations, which are increasingly offshore to benefit stronger and more uniform wind conditions. Cost of operation and maintenance of offshore wind turbines is among 15-35% of the total cost. From this, 80% comes from unplanned maintenance due to different faults in the wind turbine components. Thus, an auspicious way to contribute to the increasing demands and challenges is by applying low-cost advanced fault detection schemes. This work proposes a new method for fault detection of wind turbine actuators and sensors faults in variable-speed wind turbines. For this purpose, time domain signals acquired from the operating wind turbine are converted into two-dimensional matrices to obtain gray-scale digital images. Then, the image pattern recognition is processed getting texture features under a multichannel representation. In this work, four types of texture features are used: statistical, wavelet, granulometric and Gabor features. Then, the most significant features are selected with the conditional mutual criterion. Finally, the fault detection is performed using an automatic classification tool. In particular, a 10-fold cross validation is used to obtain a more generalized model and evaluate the classification performance. In this way, the healthy and faulty conditions of the wind turbine can be detected. Coupled non-linear aero-hydro-servo-elastic simulations of a 5MW offshore type wind turbine are carried out for several fault scenarios. The results show a promising methodology able to detect the most common wind turbine faults.
2016-12-12T12:43:05ZMujica Delgado, Luis EduardoRuiz Ordóñez, MagdaAcho Zuppa, LeonardoAlférez Baquero, Edwin SantiagoTutivén Gálvez, ChristianVidal Seguí, YolandaRodellar Benedé, JoséThe future of wind energy industry passes through the use of larger and more flexible wind turbines in remote locations, which are increasingly offshore to benefit stronger and more uniform wind conditions. Cost of operation and maintenance of offshore wind turbines is among 15-35% of the total cost. From this, 80% comes from unplanned maintenance due to different faults in the wind turbine components. Thus, an auspicious way to contribute to the increasing demands and challenges is by applying low-cost advanced fault detection schemes. This work proposes a new method for fault detection of wind turbine actuators and sensors faults in variable-speed wind turbines. For this purpose, time domain signals acquired from the operating wind turbine are converted into two-dimensional matrices to obtain gray-scale digital images. Then, the image pattern recognition is processed getting texture features under a multichannel representation. In this work, four types of texture features are used: statistical, wavelet, granulometric and Gabor features. Then, the most significant features are selected with the conditional mutual criterion. Finally, the fault detection is performed using an automatic classification tool. In particular, a 10-fold cross validation is used to obtain a more generalized model and evaluate the classification performance. In this way, the healthy and faulty conditions of the wind turbine can be detected. Coupled non-linear aero-hydro-servo-elastic simulations of a 5MW offshore type wind turbine are carried out for several fault scenarios. The results show a promising methodology able to detect the most common wind turbine faults.On the construction of high dimensional simple games
http://hdl.handle.net/2117/97663
On the construction of high dimensional simple games
Olsen, Martin; Kurz, Sascha; Molinero Albareda, Xavier
Voting is a commonly applied method for the aggregation
of the preferences of multiple agents into a joint decision. If preferences are binary, i.e., “yes” and “no”, every voting system can be
described by a (monotone) Boolean function : f0; 1gn ! f0; 1g.
However, its naive encoding needs 2n bits. The subclass of threshold
functions, which is sufficient for homogeneous agents, allows
a more succinct representation using n weights and one threshold.
For heterogeneous agents one can represent as an intersection of k
threshold functions. Taylor and Zwicker have constructed a sequence
of examples requiring k 2 n2 ¿1 and provided a construction guaranteeingk ¿ n bn=2c 2 2n¿o(n). The magnitude of the worst case situation was thought to be determined by Elkind et al. in 2008, but the analysis unfortunately turned out to be wrong. Here we uncover a relation to coding theory that allows the determination of the minimum number k for a subclass of voting systems. As an application, we give a construction for k 2n¿o(n), i.e., there is no gain from a representation complexity point of view.
2016-12-01T19:18:00ZOlsen, MartinKurz, SaschaMolinero Albareda, XavierVoting is a commonly applied method for the aggregation
of the preferences of multiple agents into a joint decision. If preferences are binary, i.e., “yes” and “no”, every voting system can be
described by a (monotone) Boolean function : f0; 1gn ! f0; 1g.
However, its naive encoding needs 2n bits. The subclass of threshold
functions, which is sufficient for homogeneous agents, allows
a more succinct representation using n weights and one threshold.
For heterogeneous agents one can represent as an intersection of k
threshold functions. Taylor and Zwicker have constructed a sequence
of examples requiring k 2 n2 ¿1 and provided a construction guaranteeingk ¿ n bn=2c 2 2n¿o(n). The magnitude of the worst case situation was thought to be determined by Elkind et al. in 2008, but the analysis unfortunately turned out to be wrong. Here we uncover a relation to coding theory that allows the determination of the minimum number k for a subclass of voting systems. As an application, we give a construction for k 2n¿o(n), i.e., there is no gain from a representation complexity point of view.Hydrological soil behavior in Beni Chougrane Mountains (Algeria)
http://hdl.handle.net/2117/97635
Hydrological soil behavior in Beni Chougrane Mountains (Algeria)
Boukhari, Yahia; Ginovart Gisbert, Marta; Verdú González, Antoni Maria Claret; Mas, Maite; Mederbal, Khalladi; Josa March, Ramon
ORSTOM rainfall simulator, Algeria, slope, rainfall intensity, initial soil moisture,
contour strip-cropping.
2016-12-01T15:56:06ZBoukhari, YahiaGinovart Gisbert, MartaVerdú González, Antoni Maria ClaretMas, MaiteMederbal, KhalladiJosa March, RamonORSTOM rainfall simulator, Algeria, slope, rainfall intensity, initial soil moisture,
contour strip-cropping.Una activitat docent per introduir la programació lineal en estudis d’Enginyeria de Biosistemes i Agroalimentària a través de problemes de dietes, planificació i produccions
http://hdl.handle.net/2117/97630
Una activitat docent per introduir la programació lineal en estudis d’Enginyeria de Biosistemes i Agroalimentària a través de problemes de dietes, planificació i produccions
Blanco Abellán, Mónica; Ginovart Gisbert, Marta
L’optimització de funcions lineals amb restriccions lineals sobre les seves variables, o
programació lineal, és un dels continguts dels fonaments matemàtics que s’imparteixen en
els quatre graus d’Enginyeria de Biosistemes i Agroalimentària que es poden cursar a
l’Escola Superior d’Agricultura de Barcelona de la Universitat Politècnica de Catalunya.
L’objectiu d’aquesta contribució és presentar una activitat d’aula per introduir els
fonaments de la programació lineal i aplicar-los a problemes de l’àmbit de l’Enginyeria de
Biosistemes i Agroalimentària. Aquesta activitat s’ha dissenyat utilitzant dues estratègies
de resolució diferents: 1) en el cas d’una funció lineal de dues variables, a partir de la
representació gràfica del conjunt regió factible, s’estudia el comportament de la funció objectiu sobre aquest conjunt per trobar l’òptim; 2) fent ús de diversos programaris o
recursos informàtics.
2016-12-01T15:25:50ZBlanco Abellán, MónicaGinovart Gisbert, MartaL’optimització de funcions lineals amb restriccions lineals sobre les seves variables, o
programació lineal, és un dels continguts dels fonaments matemàtics que s’imparteixen en
els quatre graus d’Enginyeria de Biosistemes i Agroalimentària que es poden cursar a
l’Escola Superior d’Agricultura de Barcelona de la Universitat Politècnica de Catalunya.
L’objectiu d’aquesta contribució és presentar una activitat d’aula per introduir els
fonaments de la programació lineal i aplicar-los a problemes de l’àmbit de l’Enginyeria de
Biosistemes i Agroalimentària. Aquesta activitat s’ha dissenyat utilitzant dues estratègies
de resolució diferents: 1) en el cas d’una funció lineal de dues variables, a partir de la
representació gràfica del conjunt regió factible, s’estudia el comportament de la funció objectiu sobre aquest conjunt per trobar l’òptim; 2) fent ús de diversos programaris o
recursos informàtics.