Preferences stability: A measure of preferences changes over time

Producción CientíficaTraditionally, preferences have been considered stable although there are growing evidences that such stability is a mere theoretical assumption. Attending to this fact, it should be interesting to measure how much stability preferences provide in order to improve decision making processes. Surprisingly, no research has been found on measuring preferences stability. To overcome this drawback, this paper proposes a novel approach for measuring the stability of preferences and also for improving understanding of current and future decisions. In order to be faithful to reality, this research considers decisions like complete pre-orders on a set of alternatives. Following this reasoning, this paper provides the general concept of decision stability measure as well as two specific measures: the local and the global decision stability measure. Moreover, the main features of the novel approach are examined, including several mathematical results on the behaviour of the proposed measure. And eventually, this contribution develops two real cases of study, with in-depth analysis of preferences behaviour and their stability over time. Specifically, the first one explores into the characteristics of Spanish citizens' voting behaviour and the second one attempts to analyse European citizens' preferences about passenger car market.Este trabajo forma parte del proyecto de investigación con financiación nacional: MEC-FEDER Grant ECO2016-77900-

Reaching social consensus family budgets: The Spanish case

The study of family budgets has been traditionally used to analyse consumers’ behaviour and estimate cost-of-living since the end of 19th century. Generally speaking, the computation of the budgets has been based on two different methodologies, the prescriptive and the descriptive method. Both present several drawbacks like the comparison among different areas, family types and over time. This paper proposes a new methodology for reaching family budgets, namely social consensus family budgets, to overcome such problems and examine the main features of the novel approach. The suggested method uses the minimization of the differences with respect to the consumer’s preferences to obtain a solution that summarizes single behaviour into a social preference. This approach is especially conceived for preferences on possibly related-expenditure groups. In addition, several algorithms are introduced to compute the social family budgets. Finally, the contribution includes the Spanish case as an example of reaching some social consensus family budgets in order to show the operational character and intuitive interpretation of the proposal approach.Este trabajo forma parte del proyecto de investigación con financiación nacional: MEC-FEDER Grant ECO2016-77900-

Efecto de la erradicación del estado de portador de "Staphylococcus aureus" en la incidencia de infección de prótesis articular

Introducción. Se ha demostrado que la detección de los pacientes colonizados por S. aureus y su erradicación previene infecciones nosocomiales por el mismo en diferentes ámbitos médico- quirúrgicos. La IPA es una complicación en aumento cuyo principal agente causal es S. aureus. Material y métodos. Estudio prospectivo de intervención. Se realizó estudio de detección de colonización nasal de S. aureus mediante cultivo en pacientes con indicación de artroplastia de cadera o rodilla en el Hospital Príncipe de Asturias, durante el período del 1 de Enero a 31 de Diciembre de 2011. A los pacientes colonizados se les indicó un tratamiento con mupirocina intranasal y baño con clorhexidina durante 5 días. Se comparó la incidencia de IPA por S. aureus respecto a un grupo control de pacientes a los que se realizó el mismo tipo de cirugía entre el 1 de Enero y el 31 de Diciembre de 2010. Resultados. En el período de intervención se realizaron 416 cirugías de prótesis articular. Se realizó estudio de colonización nasal a 382 pacientes (91,8%) de los que 102 fueron positivos (26,7%) y recibieron tratamiento descolonizador. La incidencia de IPA por S. aureus a los 12 meses fue de 0,5% (2 casos) frente a 2,3% (9 casos) del grupo control (OR 0,2; IC 95% 0,4 a 0,9; p=0,04). Conclusiones. En este estudio un protocolo de detección de colonización nasal de S. aureus y descolonización de los pacientes portadores produjo un descenso de la incidencia de IPA por S. aureus

Efecto de la erradicación del estado de portador de "Staphylococcus aureus" en la incidencia de infección de prótesis articular

Introducción. Se ha demostrado que la detección de los pacientes colonizados por S. aureus y su erradicación previene infecciones nosocomiales por el mismo en diferentes ámbitos médico- quirúrgicos. La IPA es una complicación en aumento cuyo principal agente causal es S. aureus. Material y métodos. Estudio prospectivo de intervención. Se realizó estudio de detección de colonización nasal de S. aureus mediante cultivo en pacientes con indicación de artroplastia de cadera o rodilla en el Hospital Príncipe de Asturias, durante el período del 1 de Enero a 31 de Diciembre de 2011. A los pacientes colonizados se les indicó un tratamiento con mupirocina intranasal y baño con clorhexidina durante 5 días. Se comparó la incidencia de IPA por S. aureus respecto a un grupo control de pacientes a los que se realizó el mismo tipo de cirugía entre el 1 de Enero y el 31 de Diciembre de 2010. Resultados. En el período de intervención se realizaron 416 cirugías de prótesis articular. Se realizó estudio de colonización nasal a 382 pacientes (91,8%) de los que 102 fueron positivos (26,7%) y recibieron tratamiento descolonizador. La incidencia de IPA por S. aureus a los 12 meses fue de 0,5% (2 casos) frente a 2,3% (9 casos) del grupo control (OR 0,2; IC 95% 0,4 a 0,9; p=0,04). Conclusiones. En este estudio un protocolo de detección de colonización nasal de S. aureus y descolonización de los pacientes portadores produjo un descenso de la incidencia de IPA por S. aureus

Turnaround Strategy and ownsership structure in declining firms: diferences between family and non-family businesses

El presente trabajo analiza la influencia de la estructura de propiedad en las estrategias de reestructuración en empresas en crisis, específicamente, en el caso de las pequeñas y medianas empresas. En concreto, nos centramos en el estudio de las diferencias entre empresas familiares y no familiares a la hora de afrontar y reaccionar ante resultados decrecientes. Sobre una muestra de 1.807 empresas españolas (PYMEs), de las que 947 están controladas por una persona o familia, hemos encontrado que las empresas familiares con resultados negativos tienden a mantener o aumentar puestos de trabajo al tiempo que reducen sus activos a través de procesos de desinversión. Asimismo, hemos comprobado que esta relación se da con mayor intensidad en el caso de las empresas familiares de menor tamaño y edad. Finalmente, el nivel de concentración de la propiedad también parece ejercer un papel moderador.The present paper analyzes the influence of the ownership structure on turnaround strategies in declining firms, especially in the case of small and medium-sized businesses. Concretely, we focus on the study of the differences between family and non-family businesses when they react to decreasing financial results during few years. Using a sample of 1,807 Spanish firms (SMEs), 947 of them controlled by a single person or a family, we have found that family-owned businesses with negative results tend to maintain or increase the number of employees while they reduce their assets, by divestments operations. We have also confirmed that this relationship is more intense in the case of smaller and younger family-owned businesses. Finally, we have considered concentration of ownership structure as an additional moderator variable in the study

Active Ageing and Access to Technology: An Evolving Empirical Study

Researchers' interest in seeing the benefits of Internet in elderly people is now growing. The network helps this group to increase communication, avoid isolation and loneliness and to age actively. Europe decided 2012 to be the Year of Active ageing. This paper presents a descriptive study of time series analysis carried out between 2004 and 2012 with the aim of knowing how the evolution in the level, motives and needs of the use of computers and Internet by elderly people in an environment of university training focused on health and life quality is. To obtain results a question paper is to be handed out to a sample of 419 people aged between 55 and 94 and taking part in the «Inter-university Programs of Experiences» from the University of Burgos. The obtained results match up with previous studies that pointed a noticeable increase in the use of the Internet (in frequency, number of users and resources) caused by elderly people's desire to keep active, up-to-date and communicated, as well as their need to continue their learning process through tools linked to the network. Here some suggestions focused on the improvement elderly people's formation and future research on the perception of the Internet as a tool for social participation

Sparse methods for wind energy prediction

© 2012 IEEE.  Personal use of this material is permitted.  Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.International Joint Conference on Neural Networks (IJCNN), celebrado en 2012 en Brisbane, QLD, AustraliaIn this work we will analyze and apply to the prediction of wind energy some of the best known regularized linear regression algorithms, such as Ordinary Least Squares, Ridge Regression and, particularly, Lasso, Group Lasso and Elastic-Net that also seek to impose a certain degree of sparseness on the final models. To achieve this goal, some of them introduce a non-differentiable regularization term that requires special techniques to solve the corresponding optimization problem that will yield the final model. Proximal Algorithms have been recently introduced precisely to handle this kind of optimization problems, and so we will briefly review how to apply them in regularized linear regression. Moreover, the proximal method FISTA will be used when applying the non-differentiable models to the problem of predicting the global wind energy production in Spain, using as inputs numerical weather forecasts for the entire Iberian peninsula. Our results show how some of the studied sparsity-inducing models are able to produce a coherent selection of features, attaining similar performance to a baseline model using expert information, while making use of less data features.The authors of the paper acknowledge partial support from grant TIN2010-21575-C02-01 of the TIN Subprogram from Spain’s MICINN and of the C´atedra UAM-IIC en Modelado y Predicci´on. The first author is also supported by the FPU– MEC grant AP2008-00167. We also thank Red E´ectrica de Espa˜na, Spain’s TSO, for providing historic wind energy dat

Decision making process in patients with brain tumor. Concerning a case report

Justificación: La decisión sobre la alternativa terapéutica más conveniente, que corresponde al paciente asesorado por el equipo sanitario, se hace especialmente difícil en casos del mal pronóstico. Pacientes: Paciente joven con tumor cerebral, reintervenido en diversas ocasiones, al que se detecta una recidiva. Re¬sultados: En contra de la opinión del equipo multidisciplinar, el paciente decide someterse a una reintervención, falleciendo a los cuatro meses presentando una calidad de vida aceptable. Conclusiones: Se plantea la necesidad, a través de un counselling adecuado, de permitir que el paciente escoja el resultado clínico preferido tras la transmisión clara de las distintas consecuencias de cada decisión y de la probabilidad de que cada una de ellas ocurra, evitando el uso de términos confusos, como la descripción técnica de procedimientos y las sugerencias globales sobre las decisiones. Se enfatiza el respeto a la autonomía del paciente, bajo condiciones de no maleficencia.The patient´s decision regarding the most advisable therapeutic alternative is difficult, speccially in patients with poor prognosis. Patients: Young patient who was operated on several times by brain tumour and he was admitted again by tumour recurrence. Results: The patient preferred to be reoperated against the multidisciplinary team decision. His quality of life was acceptable but the patient died four months later. Conclusion: We think that the patient could be able to choose the preferred therapeutic option after adequate counselling. Confusing terms such as technical description should be avoided. We emphasize the respect to the patient´s autonomy under non-maleficent conditions

Enforcing Group Structure through the Group Fused Lasso

We introduce the Group Total Variation (GTV) regularizer, a modification of Total Variation that uses the 2,1 norm instead of the 1 one to deal with multidimensional features. When used as the only regularizer, GTV can be applied jointly with iterative convex optimization algorithms such as FISTA. This requires to compute its proximal operator which we derive using a dual formulation. GTV can also be combined with a Group Lasso (GL) regularizer, leading to what we call Group Fused Lasso (GFL) whose proximal operator can now be computed combining the GTV and GL proximals through proximal Dykstra algorithm. We will illustrate how to apply GFL in strongly structured but ill-posed regression problems as well as the use of GTV to denoise colour images.Acknowledgements With partial support from Spain’s grant TIN2010-21575-C02-01 and the UAM–ADIC Chair for Machine Learning

Augmented mixed finite element method for the Oseen problem: A priori and a posteriori error analyses

We propose a new augmented dual-mixed method for the Oseen problem based on the pseudostress–velocity formulation. The stabilized formulation is obtained by adding to the dual-mixed approach suitable least squares terms that arise from the constitutive and equilibrium equations. We prove that for appropriate values of the stabilization parameters, the new variational formulation and the corresponding Galerkin scheme are well-posed, and a Céa estimate holds for any finite element subspaces. We also provide the rate of convergence when each row of the pseudostress is approximated by Raviart–Thomas or Brezzi–Douglas–Marini elements and the velocity is approximated by continuous piecewise polynomials. Moreover, we derive a simple a posteriori error estimator of residual type that consists of two residual terms and prove that it is reliable and locally efficient. Finally, we include several numerical experiments that support the theoretical results.Dirección de Investigación of the Universidad Católica de la Santísima Concepción (Chile) y CONICYT-Chile FONDECYT; Ministerio de Ciencia e Innovación del Gobierno de España