Nonlinear response of superparamagnets with finite damping: an analytical approach

The strongly damping-dependent nonlinear dynamical response of classical superparamagnets is investigated by means of an analytical approach. Using rigorous balance equations for the spin occupation numbers a simple approximate expression is derived for the nonlinear susceptibility. The results are in good agreement with those obtained from the exact (continued-fraction) solution of the Fokker-Planck equation. The formula obtained could be of assistance in the modelling of the experimental data and the determination of the damping coefficient in superparamagnets.Comment: 7 PR pages, 2 figure

Plata y Castañar (Villaverde, Madrid). Un ejemplo de intervenciones en el borde de la ciudad. Urbanismo por y para el realojo

En las ciudades españolas todavía persisten un buen número de áreas que presentan una serie de carencias urbanísticas, sociales, económicas, ambientales u otras. Es lo que se conoce como barrios desfavorecidos urbanos. Para esta aportación se analiza el caso de una zona del sur metropolitano madrileño como es la de Plata y Castañar. En dicho barrio vamos a tratar de desentrañar el proceso de sustitución y creación de la edifi cación existente, los problemas acontecidos durante el desarrollo de la intervención, sus difi cultades y las herramientas empleadas. Un área donde se ha intervenido frente al desfavorecimiento de forma sectorial, sobre un único elemento, el espacio construido. Aún a costa de la persistencia en el tiempo de otras graves carencias (fundamentalmente de tipo social). Una forma de intervenir muy criticada por cuanto supone la agrupación en un mismo territorio de una población desfavorecida.In the Spanish cities still persist a lot of areas with urban development, social, economic and environmental lacks. They are known as urban districts underprivileged. In this paper we would like to puzzle out the substitution and creation process of the constructions already existing, the problems occurred during the development of the intervention, its diffi culties or the tools used in a zone of Villaverde known as Plata and Castañar. This is an area where the constructed space has been the only sectorial way taken against the underprivileged at expense of the persistence of many other lacks (essentially socials). This is taken part way has been criticized due to it groups an underprivileged population in a same territory

La promoción pública de vivienda, ¿una solución en tiempos de crisis?: Ejemplos representativos en el área metropolitana de Madrid

Este texto se enmarca en el proyecto de investigación Las ciudades españolas en la etapa autonómica (1978-2012). Dinámicas, procesos y políticas, financiado por el Plan Nacional de Investigación I+D+i del Ministerio de Economía y Competitividad para el período 2010- 2013 (Código: CSO 2009-11261-(Subprograma GEOG)

On the role of the nonlocal Hartree-Fock exchange in ab initio quantum transport: Hydrogen in Platinum nanocontacts revisited

We propose a practical way to overcome the ubiquitous problem of the overestimation of the zero-bias and zero-temperature conductance, which is associated to the use of local approximations to the exchange-correlation functional in Density-Functional Theory when applied to quantum transport. This is done through partial substitution of the local exchange term in the functional by the nonlocal Hartree-Fock exchange. As a non-trivial example of this effect we revisit the smallest molecular bridge studied so far: a Hydrogen molecule placed in between Platinum nanocontacts. When applied to this system the value of the conductance diminishes as compared to the local-exchange-only value, which is in close agreement with results predicted from Time-Dependent Current-Density-Functional Theory. Our results issue a warning message on recent claims of perfect transparency of a Hydrogen molecule in Platinum nanocontacts

Solving quantum master equations in phase space by continued-fraction methods

Inspired on the continued-fraction technique to solve the classical Fokker--Planck equation, we develop continued-fraction methods to solve quantum master equations in phase space (Wigner representation of the density matrix). The approach allows to study several classes of nonlinear quantum systems subjected to environmental effects (fluctuations and dissipation), with the only limitations that the starting master equations may have. We illustrate the method with the canonical problem of quantum Brownian motion in periodic potentials.Comment: 7 pages, 3 figure

La integración del mercado eleéctrico de los países nórdicos: - NORD POOL - lecciones para otros mercados

Este artículo describe el proceso de integración del mercado eléctrico de los países nórdicos, además de establecer algunas reflexiones sobre dicha experiencia, las cuales pueden ser tenidas en cuenta por regiones que se encuentran en el mismo proceso como es el caso de la Comunidad Andina de Naciones -CAN. Inicialmente hace alusión a los elementos teóricos que fundamentan el intercambio de bienes y servicios y los principios económicos que justifican la integración de mercados y, finalmente se concentra en el caso y algunos resultados del Nord Pool.This article describes the process of integration of the electrical market of the Nord Pool, besides to establish some reflections on this experience, which can be considered by regions that are in the same process as the case of the Andean Community of Nations - CAN. Initially this paper makes reference to the theoretical elements that base the exchange of goods and services and the economic principles that justify the integration of markets and finally are concentrate abaut the case and some results of the Nord Pool

Un análisis cualitativo sobre la política de vivienda en España. La opinión de los expertos

In Spain the information about the housing park and market is clearly insufficient. In consequence the analysis about the housing problem and the own policies applied to solved it has important weakness. It has turned to the opinion of experts in analysis and management to advance in the knowledge and it has been synthesized by application of the Delphi method. By means of it, it has been consulted the characteristics of housing policies and phenomenon of the unoccupied housing. From them some reflections have been done about the nature of problems and policies applied and some proposals to improve the situation.La información sobre el parque y el mercado de vivienda en España es claramente insuficiente y, en consecuencia, el análisis sobre el problema de la vivienda y las políticas que se aplican para remediarlo poseen importantes inconsistencias. Para avanzar en el conocimiento, se ha recurrido a la opinión de expertos en análisis y gestión de políticas, que se ha sintetizado mediante la aplicación de una metodología basada en el método Delphi, en la que se ha consultado sobre las características de las políticas de vivienda y sobre el fenómeno de la vivienda desocupada respectivamente. A partir de ellas se formulan una serie de reflexiones sobre las inconsistencias en el planteamiento de las políticas que se vienen aplicando, así como algunas propuestas para mejorar la situación.L’information sur le parc et le marché de logement est clairement insuffisante en Espagne. Par conséquent, l’analyse sur le problème du logement et les politiques qui sont appliquées pour remédier lui souffrent d’importantes inconsistances. Pour avancer dans la connaissance on a recouru à l’opinion d’experts en analyse et gestion de politiques. On a été synthétisée selon la méthode Delphi. Ils ont été consultés sur les caractéristiques des politiques de logement et sur le phénomène du logement vacant respectivement. À partir d’elles on formule une série de réflexions sur la nature et la caractérisation des problèmes et des politiques qui sont appliquées ainsi que quelques propositions pour améliorer la situation

Innovative teaching methods in Engineering

[EN] Engineering and innovation are inseparable concepts [1]. This symbiotic relationship is shown in engineers’ workplaces, in engineering research and development processes but also is present in engineers’ education methods

Coverage Based Testing for Service Level Agreements

Service level agreements (SLAs) are typically used to specify rules regarding the consumption of services that are agreed between the providers of the service-based applications (SBAs) and their consumers. An SLA includes a list of terms that contain the guarantees that must be fulfilled during the provisioning and consumption of the services. Since the violation of such guarantees may lead to the application of potential penalties, it is important to assure that the SBA behaves as expected. In this paper, we propose a proactive approach to test SLA-aware SBAs by means of identifying test requirements, which represent situations that are relevant to be tested. To address this issue, we define a four-valued logic that allows evaluating both the individual guarantee terms and their logical relationships. Grounded in this logic, we devise a test criterion based on the modified condition decision coverage (MCDC) in order to obtain a cost-effective set of test requirements from the structure of the SLA. Furthermore by analyzing the syntax and semantics of the agreement, we define specific rules to avoid non-feasible test requirements. The whole approach has been automated and applied over an eHealth case study

Identifying Test Requirements by Analyzing SLA Guarantee Terms

Service Level Agreements (SLAs) are used to specify the negotiated conditions between the provider and the consumer of services. In this paper we present a stepwise method to identify and categorize a set of test requirements that represent the potential situations that can be exercised regarding the specification of each isolated guarantee term of an SLA. This identification is addressed by means of devising a set of coverage levels that allow grading the thoroughness of the tests. The utilization of these test requirements would focus on twofold objectives: (1) the generation of a test suite that allows exercising the situations described in the test requirements and (2) the support for the derivation of a monitoring plan that checks the compliance of these requirements at runtime. The approach is illustrated over an eHealth case study