A review of convex approaches for control, observation and safety of linear parameter varying and Takagi-Sugeno systems

This paper provides a review about the concept of convex systems based on Takagi-Sugeno, linear parameter varying (LPV) and quasi-LPV modeling. These paradigms are capable of hiding the nonlinearities by means of an equivalent description which uses a set of linear models interpolated by appropriately defined weighing functions. Convex systems have become very popular since they allow applying extended linear techniques based on linear matrix inequalities (LMIs) to complex nonlinear systems. This survey aims at providing the reader with a significant overview of the existing LMI-based techniques for convex systems in the fields of control, observation and safety. Firstly, a detailed review of stability, feedback, tracking and model predictive control (MPC) convex controllers is considered. Secondly, the problem of state estimation is addressed through the design of proportional, proportional-integral, unknown input and descriptor observers. Finally, safety of convex systems is discussed by describing popular techniques for fault diagnosis and fault tolerant control (FTC).Peer ReviewedPostprint (published version

Hazañas de los franceses y su valor en España : decimas

CCPB000077156-

Efficiency, profitability and carbon footprint of different management programs under no-till to control herbicide resistant Papaver rhoeas

The present work examines the effects of different integrated weed management (IWM) programs on multiple herbicide-resistant Papaver rhoeas populations in terms of effectiveness, profitability and carbon footprint. With this aim a trial was established in a winter cereal field under no-till in North-Eastern Spain during three consecutive seasons. Four IWM programs with different intensification levels, from less (crop rotation, mechanical control, and no herbicides) to more intense (wheat monoculture with high chemical inputs), were established. The different strategies integrated in the four programs were efficient in managing the weed after three years, with increased effectiveness after management program intensification. Whereas low input program (which includes fallow season) represented less economic cost than the other programs, on average, no differences were observed on carbon foot print, considered as kg CO2eq kg−1 product, between the different programs, except in the crop rotation program due to the low pea yield obtained. The results from this study show that in the search for a balance between crop profitability and reduction of the carbon footprint while controlling an herbicide resistant population is challenging, and particularly under notill. In this scenario the short term priority should be to reduce the presence of multiple herbicide resistant biotypes integrating the different available chemical, cultural, and physical strategies.This work has been supported by the Agencia Estatal de Investigación (AEI) and the European Regional Development Fund (ERDF) with project AGL2014-52465-C4-2-R. Dr. J. Torra obtained a Ramon y Cajal contract from the Spanish Ministry of Science, Innovation and Universities (RYC2018-023866-I). Mr. F. Valencia-Gredilla obtained a PhD grant from the University of Lleida

Biological Signals of Sperm Membrane Resistance to Cryoinjury in Boars

Despite the great progress achieved in the cryopreservation of boar semen, it has not been possible to effectively counteract the negative effects on fertility and prolificacy. The boar sperm membrane (SpM) has a particular composition of phospholipids, cholesterol, and proteins that make it highly sensitive to freezing. Just at the beginning and during the freezing protocol, the sperm are exposed to factors that destabilize the membrane and increase the sensitivity to cholesterol efflux and lipid peroxidation. This is a series of events similar to physiological capacitation; they are commonly called cryocapacitation. All the molecules reported as freezability marker and those considered potential markers are directly or indirectly related to the physiology of the SpM. The above gives rise to intensify studies tending to assess their importance as facilitators of the boar semen freezing

Origins of Latin American inequality

How deep are the roots of Latin America’s economic inequalities? In this chapter we survey both the history and the literature about the region’s extreme economic disparities, focusing on the most recent academic contributions. We begin by documenting the broad patterns of national and sub-national differences in income and inequality, building on the seminal contributions of Engerman and Sokoloff (2000; 2002, 2005) and aiming to capture different dimensions of inequality. We then proceed thematically, providing empirical evidence and summarizing the key recent studies on colonial institutions, slavery, land reform, education and the role of elites. Finally, we conduct a “replication” exercise with some seminal papers in the literature, extending their economic results to include different measures of inequality as outcomes

Actuator and sensor fault estimation based on a proportional-integral quasi-LPV observer with inexact scheduling parameters

© 2019. ElsevierThis paper presents a method for actuator and sensor fault estimation based on a proportional-integral observer (PIO) for a class of nonlinear system described by a polytopic quasi-linear parameter varying (qLPV) mathematical model. Contrarily to the traditional approach, which considers measurable or unmeasurable scheduling parameters, this work proposes a methodology that considers inexact scheduling parameters. This condition is present in many physical systems where the scheduling parameters can be affected by noise, offsets, calibration errors, and other factors that have a negative impact on the measurements. A H8 performance criterion is considered in the design in order to guarantee robustness against sensor noise, disturbance, and inexact scheduling parameters. Then, a set of linear matrix inequalities (LMIs) is derived by the use of a quadratic Lyapunov function. The solution of the LMI guarantees asymptotic stability of the PIO. Finally, the performance and applicability of the proposed method are illustrated through a numerical experiment in a nonlinear system.Peer ReviewedPostprint (author's final draft

Leadership groups on Social Network Sites based on Personalized PageRank

n this paper we present a new framework to identify leaders in a Social Network Site using the Personalized PageRank vector. The methodology is based on the concept of Leadership group recently introduced by one of the authors. We show how to analyze the structure of the Leadership group as a function of a single parameter. Zachary¿s network and a Facebook university network are used to illustrate the applicability of the model.We thank an unknown referee who made some suggestive comments that improved the readability of the paper. This work is supported by Spanish DGI grant MTM2010-18674.Pedroche Sánchez, F.; Moreno, F.; González, A.; Valencia, A. (2013). Leadership groups on Social Network Sites based on Personalized PageRank. Mathematical and Computer Modelling. 57(7-8):1891-1896. https://doi.org/10.1016/j.mcm.2011.12.026S18911896577-