5,173 research outputs found
Towards a Unified Framework for Declarative Structured Communications
We present a unified framework for the declarative analysis of structured
communications. By relying on a (timed) concurrent constraint programming
language, we show that in addition to the usual operational techniques from
process calculi, the analysis of structured communications can elegantly
exploit logic-based reasoning techniques. We introduce a declarative
interpretation of the language for structured communications proposed by Honda,
Vasconcelos, and Kubo. Distinguishing features of our approach are: the
possibility of including partial information (constraints) in the session
model; the use of explicit time for reasoning about session duration and
expiration; a tight correspondence with logic, which formally relates session
execution and linear-time temporal logic formulas
3D-Mesomechanical analysis of cracking and spalling of concrete subject to high temperatures
In this paper, an existing meso-structural model for concrete which had been applied to the study of the mechanical effects of high temperatures in 2D, is extended to 3D, and to more complex coupled thermo-mechanical analysis. The material is idealized as a twophase compositein which all mesh lines (or surfaces in 3D) are potential cracks equipped with fracture-based zero-thickness interface elements. Different thermal expansion laws are assumed for matrix and particles, whereby the deformation mismatch can generate cracking. Temperature distributions are obtained from a separate thermal diffusionanalysis.The thermal analysis is first assumed uncoupled, but then also coupled with the mechanical analysis, as the layers of material spalloff and the boundary conditionsare moved to the new domain boundaries. The new computational results in 3D are compared to basic experimental observations reported in the literature and to the previous computational results obtained in 2D
3D-Mesomechanical analysis of external sulfate attack in concrete
The present study focuses on degradation of concrete by external sulfate attack. The numerical model developed by the MECMAT/UPC group, incorporates coupled C-M analysis using a meso-mechanical approach with discrete cracking, using the MEF and zero thickness interface elements with a constitutive law based on nonlinear fracture mechanics concepts. Examples of application are run on 2D and 3D samples, with geometries and FE meshes generated with a code developed also in-house. The numerical analysis is carried out using two independent codes and a “staggered” procedure. The first code performs the mechanical analysis and the second the diffusive/reaction chemical problem. 2D uncoupled and coupled analysis are presented and discussed. Preliminary coupled 3D results are also presented and compared with equivalent 2D results, and the differences are detected and analyzed
GAMES: A new Scenario for Software and Knowledge Reuse
Games are a well-known test bed for testing search algorithms and learning methods, and many authors have presented numerous reasons for the research in this area. Nevertheless, they have not received the attention they deserve as software projects.
In this paper, we analyze the applicability of software
and knowledge reuse in the games domain. In spite of the
need to find a good evaluation function, search algorithms
and interface design can be said to be the primary concerns.
In addition, we will discuss the current state of the main
statistical learning methods and how they can be addressed
from a software engineering point of view. So, this paper
proposes a reliable environment and adequate tools, necessary in order to achieve high levels of reuse in the games domain
BHFFA*: Un nuevo algoritmo admisible de búsqueda bidireccional
A pesar de que inicialmente hubo un gran interés en los algoritmos de búsqueda bidireccionales, muy pronto se pensó que garantizar la optimalidad de las soluciones encontradas de este modo era muy complicado, y por ello se desestimó esta línea de investigación. En este artículo se muestra, sin embargo, que es posible superar los principales inconvenientes de la búsqueda bidireccional y desarrollar un nuevo algoritmo admisible, con una heurística consistente, y en términos muy sencillos. Además, a diferencia de otras implementaciones bidireccionales, la que se muestra aquí puede resultar en reducciones del tiempo necesario y de la memoria consumida de hasta el 99%, y siempre superior a su implementación unidireccional. Para constatarlo, se han estudiado dos dominios radicalmente diferentes: el grafo del Metro de Madrid y el juego del N-‘Puzle’
On spectra of weighted graphs of order ≤5
Producción CientíficaThe problem of characterizing the real spectra of weighted graphs is only solved
for weighted graphs of order n ≤ 4. We overview these known results, that come
from the context of nonnegative matrices, and give a new method to rule out many
unresolved spectra of size 5.Ministerio de Economía, Industria y Competitividad ( grant MTM2015-365764-C3-1-P)Universidad de Valladolid (GIR TAMCO
Numerical dynamic analysis of reciprocating compressor mechanism. Parametric studies for optimization purposes
© 2016. This version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/A complete numerical dynamic analysis of reciprocating compressor mechanism is presented, coupling the instantaneous pressure in the compression chamber, the electric motor torque and the hydrodynamic reactions, which arise from the piston and crankshaft secondary movements. Additionally, non-constant crankshaft angular velocity and the piston and crankshaft misalignment torques have also been considered. Two sensitivity analyses have been carried out to prove that neither the inertial forces in the directions of the secondary movements, nor the oscillations of the angular velocity produce significant differences in the compressor behaviour. Finally, a set of parametric studies has been developed to evaluate the influence of geometrical parameters in the stability of the secondary movements, the friction power losses and the compressor consumptionPeer ReviewedPostprint (author's final draft
A note for the SNIEP in size 5
Producción CientíficaThe purpose of this note is to establish the current state of the knowledge about the SNIEP (symmetric nonnegative inverse eigenvalue problem) in size 5 with just one repeated eigenvalue.Ministerio de Ciencia e Innovación - AEI (grant PGC2018-096446-B-C21)Consejo Superior de Investigaciones Científicas de España (Comisión Interministerial de Ciencia y Tecnología) (PID2021-122501NB-I00
An empirical analysis of the relationship between the information quality of CSR reporting and reputation among publicly traded companies in Spain
RESUMEN. Objetivo. Basándose en la teoría de la legitimidad, los autores de este trabajo exploran la relación que existe entre la calidad de la información contenida en las memorias de responsabilidad social corporativa (RSC) de las principales empresas cotizadas en la bolsa española y su reputación corporativa. Diseño/metodología/enfoque. Se testean tres modelos de regresión con un panel de datos recopilados entre 2004 y 2014 para una muestra de las 35 empresas más sólidas de la bolsa española.
Resultados. Los resultados muestran que los dos ejes principales de la calidad de la información (es decir, contenido y sistemas de gestión) deben ser necesariamente controlados por las empresas con el fin de mejorar su reputación corporativa a través de sus memorias de RSC. El eje de contenido se refiere al cumplimiento de las memorias de RSC con el suministro de información cualitativa, cuantitativa y de evaluación en relación con los impactos de la RSC de la empresa en la sociedad y el medio ambiente. El eje de los sistemas de gestión se refiere al cumplimiento de las memorias de RSC con la divulgación de información acerca de las políticas, planes y acciones que las empresas implementan para asegurar una gestión eficaz de las iniciativas de RSC.
Originalidad/valor. La literatura previa que ha explorado la relación entre la información corporativa y la reputación se ha centrado con frecuencia en (1) el impacto de la cantidad de información financiera y de RSC que generan las empresas o (2) el papel de la calidad de la información, pero sólo en referencia a una serie de temas concretos (principalmente medio ambiente y clientes) y no a toda la gama de información cubierta por las memorias de RSC. Los autores de este trabajo amplían esta línea de investigación mediante la evaluación empírica de la relación entre dos dimensiones de la calidad de la información de las memorias de RSC (contenido y sistemas de gestión) y la reputación corporativa de las empresas que operan en la bolsa española.ABSTRACT.
Purpose. Supported by the principles of the legitimacy theory, the purpose of this paper is to explore the relationship that exists between the information quality of the corporate social responsibility (CSR) reporting provided by the most liquid companies operating in the Spanish Stock Market and their corporate reputation. Design/methodology/approach.
Three regression models are tested with panel data collected for a sample of the 35 most liquid companies operating in the Spanish Stock Market between 2004 and 2014. Findings. The findings show that two axes of information quality (i.e. content and management systems) should be necessarily controlled by companies in order to improve their corporate reputation through their CSR reporting. The content axis refers to the compliance of CSR reports with the provision of qualitative, quantitative, and evaluative information concerning the impacts of the CSR of the company on society and the environment. The management systems axis refers to the compliance of CSR reports with the disclosure of details about the policies, plans, and actions that companies implement to assure an effective management of CSR initiatives. Originality/value. Previous literature exploring the relationship between corporate reporting and reputation has frequently focused on either the impact of the quantity of financial and CSR information reported by companies and the role of information quality, but only in reference to a number of specific themes (environment, customers) and not to the full range of information covered by CSR reports. The authors of this paper extend on previous academic literature by empirically evaluating the relationship between two dimensions of the information quality of CSR reporting (content and management systems) and the corporate reputation of companies operating in the Spanish Stock Market
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