http://hdl.handle.net/10256/1546 2013-05-24T13:15:52Z 2013-05-24T13:15:52Z Blaho, Miklos Egri, Adam Bahidszki, Lea Kriska, Gyorgy Hegedüs, Ramon Akesson, Susanne Horvath, Gabor http://hdl.handle.net/10256/7789 2013-05-08T00:00:43Z 2012-08-01T00:00:00Z

Spottier Targets Are Less Attractive to Tabanid Flies: On the Tabanid-Repellency of Spotty Fur Patterns Blaho, Miklos; Egri, Adam; Bahidszki, Lea; Kriska, Gyorgy; Hegedüs, Ramon; Akesson, Susanne; Horvath, Gabor During blood-sucking, female members of the family Tabanidae transmit pathogens of serious diseases and annoy their host animals so strongly that they cannot graze, thus the health of the hosts is drastically reduced. Consequently, a tabanid-resistant coat with appropriate brightness, colour and pattern is advantageous for the host. Spotty coats are widespread among mammals, especially in cattle (Bos primigenius). In field experiments we studied the influence of the size and number of spots on the attractiveness of test surfaces to tabanids that are attracted to linearly polarized light. We measured the reflection-polarization characteristics of living cattle, spotty cattle coats and the used test surfaces. We show here that the smaller and the more numerous the spots, the less attractive the target (host) is to tabanids. We demonstrate that the attractiveness of spotty patterns to tabanids is also reduced if the target exhibits spottiness only in the angle of polarization pattern, while being homogeneous grey with a constant high degree of polarization. Tabanid flies respond strongly to linearly polarized light, and we show that bright and dark parts of cattle coats reflect light with different degrees and angles of polarization that in combination with dark spots on a bright coat surface disrupt the attractiveness to tabanids. This could be one of the possible evolutionary benefits that explains why spotty coat patterns are so widespread in mammals, especially in ungulates, many species of which are tabanid hosts

2012-08-01T00:00:00Z Calderón-Espinoza, Gabriela Armengol Llobet, Joaquim Vehí i Casellas, Josep Gelso, Esteban Reinaldo http://hdl.handle.net/10256/7504 2013-04-16T15:29:51Z 2007-01-01T00:00:00Z

Dynamic diagnosis based on interval analytical redundancy relations and signs of the symptoms Calderón-Espinoza, Gabriela; Armengol Llobet, Joaquim; Vehí i Casellas, Josep; Gelso, Esteban Reinaldo A model-based approach for fault diagnosis is proposed, where the fault detection is based on checking the consistency of the Analytical Redundancy Relations (ARRs) using an interval tool. The tool takes into account the uncertainty in the parameters and the measurements using intervals. Faults are explicitly included in the model, which allows for the exploitation of additional information. This information is obtained from partial derivatives computed from the ARRs. The signs in the residuals are used to prune the candidate space when performing the fault diagnosis task. The method is illustrated using a two-tank example, in which these aspects are shown to have an impact on the diagnosis and fault discrimination, since the proposed method goes beyond the structural methods

2007-01-01T00:00:00Z Torrent-Fontbona, Ferran Muñoz Solà, Víctor López Ibáñez, Beatriz http://hdl.handle.net/10256/7310 2013-02-28T07:33:40Z 2012-01-01T00:00:00Z

Exploring Genetic Algorithms and Simulated Annealing for Immobile Location-Allocation Problem Torrent-Fontbona, Ferran; Muñoz Solà, Víctor; López Ibáñez, Beatriz In this paper we introduce a new kind of immobile Location-Allocation problem that consists in determining the service each facility has to offer in order to maximize the covered demand given the positions of the customers and their service requirements and the positions of the immobile facilities. First, we provide a formalization of the problem and then we tackle the problem using two heuristic methods, genetic algorithms and simulated annealing, comparing the performance of both algorithms Artificial Intelligence Research and Development - Proceedings of the 15th International Conference of the Catalan Association for Artificial Intelligence

2012-01-01T00:00:00Z Karimi, Hamid Reza Zapateiro de la Hoz, Mauricio Fabián Luo, Ningsu http://hdl.handle.net/10256/3446 2012-11-23T07:27:22Z 2009-01-01T00:00:00Z

New delay-dependent stability criteria for uncertain neutral systems with mixed time-varying delays and nonlinear perturbations Karimi, Hamid Reza; Zapateiro de la Hoz, Mauricio Fabián; Luo, Ningsu The problem of stability analysis for a class of neutral systems with mixed time-varying neutral, discrete and distributed delays and nonlinear parameter perturbations is addressed. By introducing a novel Lyapunov-Krasovskii functional and combining the descriptor model transformation, the Leibniz-Newton formula, some free-weighting matrices, and a suitable change of variables, new sufficient conditions are established for the stability of the considered system, which are neutral-delay-dependent, discrete-delay-range dependent, and distributeddelay-dependent. The conditions are presented in terms of linear matrix inequalities (LMIs) and can be efficiently solved using convex programming techniques. Two numerical examples are given to illustrate the efficiency of the proposed method

2009-01-01T00:00:00Z Zapateiro de la Hoz, Mauricio Fabián Luo, Ningsu Karimi, Hamid Reza http://hdl.handle.net/10256/2736 2012-11-23T07:27:37Z 2008-01-01T00:00:00Z

QFT control for vibration reduction in structures equipped with MR dampers Zapateiro de la Hoz, Mauricio Fabián; Luo, Ningsu; Karimi, Hamid Reza This short paper addresses the problem of designing a QFT (quantitative feedback theory) based controllers for the vibration reduction in a 6-story building structure equipped with shear-mode magnetorheological dampers. A new methodology is proposed for characterizing the nonlinear hysteretic behavior of the MR damper through the uncertainty template in the Nichols chart. The design procedure for QFT control design is briefly presented

2008-01-01T00:00:00Z Vehí i Casellas, Josep Sainz, Miguel Ángel http://hdl.handle.net/10256/2735 2012-06-28T12:30:36Z 1999-01-01T00:00:00Z

Necessary and sufficient conditions for robust stability using modal intervals Vehí i Casellas, Josep; Sainz, Miguel Ángel In this paper, robustness of parametric systems is analyzed using a new approach to interval mathematics called Modal Interval Analysis. Modal Intervals are an interval extension that, instead of classic intervals, recovers some of the properties required by a numerical system. Modal Interval Analysis not only simplifies the computation of interval functions but allows semantic interpretation of their results. Necessary, sufficient and, in some cases, necessary and sufficient conditions for robust performance are presented

1999-01-01T00:00:00Z Quintero Monroy, Christian G. Rosa, Josep Lluís de la Vehí i Casellas, Josep http://hdl.handle.net/10256/2686 2012-06-28T12:30:36Z 2005-01-01T00:00:00Z

Studies about the atomic capabilities concept for linear control systems in physical multi-agent environments Quintero Monroy, Christian G.; Rosa, Josep Lluís de la; Vehí i Casellas, Josep This paper shows the impact of the atomic capabilities concept to include control-oriented knowledge of linear control systems in the decisions making structure of physical agents. These agents operate in a real environment managing physical objects (e.g. their physical bodies) in coordinated tasks. This approach is presented using an introspective reasoning approach and control theory based on the specific tasks of passing a ball and executing the offside manoeuvre between physical agents in the robotic soccer testbed. Experimental results and conclusions are presented, emphasising the advantages of our approach that improve the multi-agent performance in cooperative systems

2005-01-01T00:00:00Z Pous i Sabadí, Carles Caballero, Dani López Ibáñez, Beatriz http://hdl.handle.net/10256/2680 2012-11-29T10:25:37Z 2008-01-01T00:00:00Z

Diagnosing Patients Combining Principal Components Analysis and Case Based Reasoning Pous i Sabadí, Carles; Caballero, Dani; López Ibáñez, Beatriz This paper addresses the application of a PCA analysis on categorical data prior to diagnose a patients data set using a Case-Based Reasoning (CBR) system. The particularity is that the standard PCA techniques are designed to deal with numerical attributes, but our medical data set contains many categorical data and alternative methods as RS-PCA are required. Thus, we propose to hybridize RS-PCA (Regular Simplex PCA) and a simple CBR. Results show how the hybrid system produces similar results when diagnosing a medical data set, that the ones obtained when using the original attributes. These results are quite promising since they allow to diagnose with less computation effort and memory storage

2008-01-01T00:00:00Z Peña de Carrillo, Clara Inés Marzo i Lázaro, Josep Lluís Rosa, Josep Lluís de la http://hdl.handle.net/10256/2679 2012-12-21T07:55:10Z 2004-01-01T00:00:00Z

Curriculum sequencing for an e-learning system based on learning styles Peña de Carrillo, Clara Inés; Marzo i Lázaro, Josep Lluís; Rosa, Josep Lluís de la This work shows the use of adaptation techniques involved in an e-learning system that considers students' learning styles and students' knowledge states. The mentioned e-learning system is built on a multiagent framework designed to examine opportunities to improve the teaching and to motivate the students to learn what they want in a user-friendly and assisted environment

2004-01-01T00:00:00Z Zapateiro de la Hoz, Mauricio Fabián Karimi, Hamid Reza Luo, Ningsu Phillips, Brian M. Spencer, Billie F. http://hdl.handle.net/10256/2678 2012-11-23T07:27:07Z 2009-01-01T00:00:00Z

A mixed H2/H∞-based semiactive control for vibration mitigation in flexible structures Zapateiro de la Hoz, Mauricio Fabián; Karimi, Hamid Reza; Luo, Ningsu; Phillips, Brian M.; Spencer, Billie F. In this paper, we address this problem through the design of a semiactive controller based on the mixed H2/H∞ control theory. The vibrations caused by the seismic motions are mitigated by a semiactive damper installed in the bottom of the structure. It is meant by semiactive damper, a device that absorbs but cannot inject energy into the system. Sufficient conditions for the design of a desired control are given in terms of linear matrix inequalities (LMIs). A controller that guarantees asymptotic stability and a mixed H2/H∞ performance is then developed. An algorithm is proposed to handle the semiactive nature of the actuator. The performance of the controller is experimentally evaluated in a real-time hybrid testing facility that consists of a physical specimen (a small-scale magnetorheological damper) and a numerical model (a large-scale three-story building)

2009-01-01T00:00:00Z