Autoregressive time series prediction by means of fuzzy inference systems using nonparametric residual variance estimation

We propose an automatic methodology framework for short- and long-term prediction of time series by means of fuzzy inference systems. In this methodology, fuzzy techniques and statistical techniques for nonparametric residual variance estimation are combined in order to build autoregressive predictive models implemented as fuzzy inference systems. Nonparametric residual variance estimation plays a key role in driving the identification and learning procedures. Concrete criteria and procedures within the proposed methodology framework are applied to a number of time series prediction problems. The learn from examples method introduced by Wang and Mendel (W&M) is used for identification. The Levenberg–Marquardt (L–M) optimization method is then applied for tuning. The W&M method produces compact and potentially accurate inference systems when applied after a proper variable selection stage. The L–M method yields the best compromise between accuracy and interpretability of results, among a set of alternatives. Delta test based residual variance estimations are used in order to select the best subset of inputs to the fuzzy inference systems as well as the number of linguistic labels for the inputs. Experiments on a diverse set of time series prediction benchmarks are compared against least-squares support vector machines (LS-SVM), optimally pruned extreme learning machine (OP-ELM), and k-NN based autoregressors. The advantages of the proposed methodology are shown in terms of linguistic interpretability, generalization capability and computational cost. Furthermore, fuzzy models are shown to be consistently more accurate for prediction in the case of time series coming from real-world applications.Ministerio de Ciencia e Innovación TEC2008-04920Junta de Andalucía P08-TIC-03674, IAC07-I-0205:33080, IAC08-II-3347:5626

DICTADORES O DEMÓCRATAS CONSECUENCIAS DE LA DISTANCIA DE PODER PREVALENTE EN LA ORGANIZACIÓN LATINOAMERICANA

Several impediments to democracy in groups, organizations, communities, and nations in Latin America are discussed in this article. These roadblocks can be traced to the mental models prevalent in the Latin American cultures. The main conclusion is that the Latino tends to be closer to the socio-cultural conditions that favor dictatorships and undermine democracy. More concretely, democratization in Latin America is limited by many variables. Chief among them are: Timidity toward organizational and social change, parochialism, orientation toward the past, preference for the status quo, hierarchy, power distance, classism, sectarianism, authoritarianism, vertical decision-making structures, organizational rigidity, and low social synergy. These features permeate the political cultures in Latin American countries, as well as their managerial cultures. These cultural peculiarities represent serious obstacles to the democratic transformation of organizations and societies in the region. Important changes in values, attitudes, and behaviors (among individuals, organizations, communities, and even nations) are necessary to overcome the impediments discussed here

Concepciones del conocimiento en la formación de trabajadores sociales en Suecia.

In this paper we discuss knowledge conceptions implicit in social workers’ academic education in Sweden, knowledge conceptions often introduced as incompatible. We sustain that behind this image of incompatibility there are differences but also common assumptions. This paper is based on the review of documents treating different aspects of the social workers’ education in Sweden. Analysis focuses on three different periods in the history of the Social Work Education: first period tackles the establishment of the first educational program; second period considers the establishment of the social work as an academic discipline; and the third period deals with the current situation. The different knowledge conceptions prevailing in each period respond as much to the society demands as to the internal exigencies of the academic world.En este artículo debatimos sobre las concepciones del conocimiento implícitas en la formación académica de trabajadores sociales en Suecia, concepciones que a menudo se presentan como incompatibles. Sostenemos que detrás de esa imagen de incompatibilidad existen diferencias, pero también presupuestos comunes. Este artículo se basa en la lectura de documentos que tratan de diferentes aspectos de la educación de trabajadores sociales en Suecia. El análisis se concentra en tres períodos de la historia de la educación en Trabajo Social: el primer período, aborda el establecimiento del primer programa de educación; el segundo período contempla el establecimiento de Trabajo Social como disciplina académica; y el tercer período trata de la situación actual. Las diferentes concepciones del conocimiento dominantes en cada uno de esos períodos responden tanto a las demandas de la sociedad como a las exigencias internas del mundo académico

Trabajo Social en Suecia, tendencias generales y el caso particular de los niños migrantes

The restructuring of the Swedish welfare state and increasing inequalities are social transformations over the past three decades. Sweden has lost its leading position in the international rankings of social equality. New ways of understanding and addressing social problems allow privatization of social services, public before. In addition, demographic changes such as increased international mobility and complexity in the dynamics of social problems demand new responses from social services, which have clear implications for social work, which emerged as a territorially bounded activity by national borders. The case of migrant children is an example, as it clearly states these new problems and shows various and contradictory responses from the services of child protection. In this paper we discuss the responses by social workers in care cases and institutionalized responses from foster care. In those places is detected the failure of institutionalized forms of child protection. In the individual case-work we see an emergence of critical responses among social workers, who within the legal framework question the tradition of loyalty to Swedish state authority in social work. Replies apart, we see also arise organizations challenging repressive policies and try to work from a perspective that takes into account the issues affecting migrant children.La reestructuración del Estado de bienestar sueco y el aumento de las desigualdades son transformaciones sociales ocurridas durante los tres últimos decenios. Suecia ha perdido su posición de liderazgo en los rankings internacionales sobre igualdad social. Nuevas formas de entender y abordar los problemas sociales permiten la privatización de los servicios sociales, antes públicos. Además, cambios demográficos como el aumento de la movilidad internacional y la complejidad en la dinámica de los problemas sociales exigen nuevas respuestas de los servicios sociales, lo que tiene claras implicaciones para el Trabajo Social, que surgió como una actividad delimitada territorialmente por las fronteras nacionales. El caso de los niños migrantes es un ejemplo, ya que expresa claramente esas nuevas problemáticas y muestra diversas y contradictorias respuestas desde los servicios de protección de la infancia. En este artículo discutimos las respuestas que dan los trabajadores sociales en la atención de casos y las respuestas institucionalizadas desde los hogares de acogida. En esos lugares detectamos el fracaso de las formas institucionalizadas de protección de la infancia. En la atención de casos individuales vemos surgir respuestas que, dentro de los marcos de la legalidad, cuestionan una tradición de lealtad y subordinación a la autoridad en la historia del Trabajo Social en Suecia. Respuestas aparte, vemos también surgir organizaciones que cuestionan políticas represivas e intentan trabajar desde una perspectiva que toma en cuenta las problemáticas que afectan a los niños migrantes

Medida y estimación activa de las prestaciones de la red

Los sistemas de medida y estimación activa de prestaciones de redes se basan en la medida de la respuesta de la red frente a tráfico de prueba transmitido entre nodos de extremo a extremo. En esta ponencia presentamos un entorno integrado de medida y estimación activa de prestaciones. El entorno generaliza, unifica y amplía el conjunto de técnicas de medida y estimación activa disponible hasta la fecha, ofreciendo una interfaz de usuario unificada, una de programación común y librerías que implementan de manera autónoma los diferentes componentes de un sistema de medida y estimación activa genérico. Se resumen asimismo las mejoras aportadas por el entorno desarrollado y su posibilidades de ampliación futura.Network performance active measurement and estimation systems are based on the response to test traffic between two end-points in the network. This paper presents an integrated environment for the active measurement and estimation of network performance. The environment has been conceived as a generalization, unification and extension to the set of active measurement and estimation techniques available to date. It offers a unified user interface, a common programming one and libraries that provide stand-alone implementations for the different components of a generic active measurement and estimation system. Contributions and improvements achieved by means of the presented environment as well as possible future extensions are also outline