485 research outputs found
Measuring and Controlling Multicore Contention in a RISC-V System-on-Chip
[ES] Los procesadores multinúcleo empezaron una revolución en el cómputo moderno cuando fueron introducidos en el espacio de cómputo comercial y de consumidor. Estos procesadores multinúcleo presentaban un aumento significativo en consumo, eficiencia y rendimiento en un periodo de tiempo en el aumento de la frecuencia y el IPC del procesador parecÃa estar tocando techo. Sin embargo, en sistemas crÃticos, la introducción de los procesadores multinúcleo ha traÃdo a la luz diferentes dificultades en el proceso de certificación. La principal área que dificulta la caracterización de los sistemas multicore en tiempo real es el uso de recursos compartidos, en especÃfico, los buses compartidos.
En este trabajo proveeremos las herramientas necesarias para facilitar la caracterización de sistemas que hacen uso de buses compartidos en sistemas de criticidad mixta. En especÃfico, combinamos las polÃticas desarrolladas para sistemas con buses con polÃticas de limitación de ancho de banda basadas en interferencia causada al núcleo principal. Con esta combinación de polÃticas podemos limitar el WCET de la tarea crÃtica en el sistema multinúcleo mientras que proveemos un "best effort" para permitir el progreso en los núcleos secundarios.[CAT] Els processadors multinucli van començar una revolució en el còmput modern quan
van ser introduïts en l’espai de còmput comercial i de consumidor. Aquests processadors
multinucli presentaven un augment significatiu en consum, eficiència i rendiment en un
perÃode de temps en l’augment de la freqüència i l’IPC de l’processador semblava estar
tocant sostre. No obstant això, en sistemes crÃtics, la introducció dels processadors multi-
nucli ha portat a la llum diferents dificultats en el procés de certificació. La principal à rea
que dificulta la caracterització dels sistemes multinucli en temps real és l’ús de recursos
compartits, en especÃfic, els busos compartits.
En aquest treball proveirem les eines necessà ries per facilitar la caracterització de sis-
temes que fan ús de busos compartits en sistemes de criticitat mixta. En especÃfic, combi-
nem les polÃtiques desenvolupades per a sistemes amb busos amb polÃtiques de limitació
d’ample de banda basades en interferència causada a el nucli principal. Amb aquesta
combinació de polÃtiques podem limitar l’WCET de la tasca crÃtica en el sistema multinu-
cli mentre que proveïm un "best effort"per permetre el progrés en els nuclis secundaris.[EN] Multicore processors were a revolution when introduced into the commercial computing space, they presented great power efficiency and performance in a time where clock speeds and instruction level parallelism were plateauing. But, on safety critical systems, the introduction of multi-core processors has brought serious difficulties to the certification process. The main trouble spot for multicore characterization is the usage of shared resources, in specific, shared buses.
In this work, we provide tools to ease the characterization of shared bus mechanisms timing interference on critical and mixed criticality systems. In particular, we combine shared bus arbitration policies with rate limiting policies based on critical workload interference to bound the WCET of a critical workload on a multi-core system while doing a best effort to let secondary cores progress as much as possible.Andreu Cerezo, P. (2021). Measuring and Controlling Multicore Contention in a RISC-V System-on-Chip. Universitat Politècnica de València. http://hdl.handle.net/10251/173563TFG
Independence and pluralism of political journalism in Spain. Contrast between journalistic, political and citizens’ perceptions
La información polÃtica representa un recurso estratégico para el funcionamiento
normativo del sistema democrático. Sus contenidos condicionan el acceso ciudadano a
los principales acontecimientos y debates sociales, determinan el establecimiento de la
agenda pública y dinamizan el proceso de formación de la opinión pública. Este trabajo
analiza el grado actual de independencia y pluralismo del periodismo polÃtico en
España. El estudio de estas dos cuestiones se aborda desde el análisis empÃrico de las
percepciones de los periodistas y actores polÃticos y su posterior contraste con la opinión
ciudadana. Los resultados indican una valoración dispar sobre la situación del
periodismo polÃtico en España. Frente a la preocupación de los ciudadanos, los periodistas
plantean un diagnóstico bastante templado, incluso optimista, a la hora de evaluar
el nivel de pluralismo informativo en España, y algo más crÃtico y matizado sobre el
grado de independencia en el ejercicio profesional.Political information is a strategic resource for the normative functioning of the
democratic system. Its contents condition citizens’ access to major events and social debates, determine the establishment of the public agenda, and stimulate the process of
forming public opinion. This paper examines the present degree of independence and
pluralism of political journalism in Spain. These two elements are approached through
an empirical analysis of the perceptions of journalists and political actors, and of how
they contrast with citizens’ opinions. Our results indicate a disparate evaluation of the
situation of political journalism in Spain. As opposed to the preoccupation of citizens,
journalists express a fairly moderate or even optimistic diagnosis when evaluating the
level of news pluralism in Spain, although the latter are somewhat more critical and
nuanced about the degree of independence in professional practice
With or without you: The role of personal affinity in relationships between journalists and politicians in Spain.
Informal relationships between journalists and politicians have a strategic function in the process of news-making. The aim of this article is to analyse the role of personal affinity between the media and politicians in Spain. This study focuses on the following three specific issues: self-definition of their interactions, degree of influence, and main professional risks and benefits detected. The methodology is based on 45 in-depth interviews (22 journalists, 16 politicians and 7 spin-doctors). The novelty of this article is the analysis of not only the views of journalists but also the perceptions of the political actors. The results demonstrate the relevance and influence of affinity relationships between journalists and politicians. The two types of actors are highlighted as main beneficiaries of direct access to high-quality information sources or the ability to achieve positive news coverage. However, certain risks are also linked to these informal relationships.The author(s) disclosed receipt of the following financial support for the research,
authorship, and/ or publication of this article: This article is part of the research project CSO2014-52283-C2-1-P funded by the Spanish Ministry of Economy and
Competitiveness
Independence and pluralism of political journalism in Spain. Contrast between journalistic, political and citizens’ perceptions
La información política representa un recurso estratégico para el funcionamiento normativo del sistema democrático. Sus contenidos condicionan el acceso ciudadano a los principales acontecimientos y debates sociales, determinan el establecimiento de la agenda pública y dinamizan el proceso de formación de la opinión pública. Este trabajo analiza el grado actual de independencia y pluralismo del periodismo político en España. El estudio de estas dos cuestiones se aborda desde el análisis empírico de las percepciones de los periodistas y actores políticos y su posterior contraste con la opinión ciudadana. Los resultados indican una valoración dispar sobre la situación del periodismo político en España. Frente a la preocupación de los ciudadanos, los periodistas plantean un diagnóstico bastante templado, incluso optimista, a la hora de evaluar el nivel de pluralismo informativo en España, y algo más crítico y matizado sobre el grado de independencia en el ejercicio profesional.Palabras clave: autonomía profesional, grado de independencia, pluralismo informativo, periodistas, actores políticos, percepción de los ciudadanos.Political information is a strategic resource for the normative functioning of the democratic system. Its contents condition citizens’ access to major events and social debates, determine the establishment of the public agenda, and stimulate the process of forming public opinion. This paper examines the present degree of independence and pluralism of political journalism in Spain. These two elements are approached through an empirical analysis of the perceptions of journalists and political actors, and of how they contrast with citizens’ opinions. Our results indicate a disparate evaluation of the situation of political journalism in Spain. As opposed to the preoccupation of citizens, journalists express a fairly moderate or even optimistic diagnosis when evaluating the level of news pluralism in Spain, although the latter are somewhat more critical and nuanced about the degree of independence in professional practice.Keywords: professional autonomy, degree of independence, news pluralism, journalists, political actors, citizens’ perceptions
Media Engagement Boundaries and Political Influence in Europe
The aim of this article is to analyze the influence level and boundaries that media
have on politics. Specifically, we study the power of media to set the public agenda,
to set the political agenda determining the decision-making process, and to generate
political disaffection through the politicians’ and journalists’ perceptions. We have
used a methodology based on in-depth interviews applied to a wide sample of 45
individuals. The analysis is focused on the European context; the case study is based
specifically on Spain. Results show a high level of mediatization of politics, but also
reveal limits to the political influence of the media. These boundaries of the media
influence on politics affects political agenda setting and its ability to generate civic
engagement. Moreover, we have detected four media engagement boundaries that
boost the citizens’ political cynicism
The cover news reporting in Spain: historical evolution of sources, agenda and frames (1980-2010)
Dentro de la cobertura informativa, la portada de la prensa de referencia representa un objeto de estudio muy relevante. A partir su análisis longitudinal, el objetivo de este trabajo es examinar la evolución de tres cuestiones periodÃsticas centrales: gestión de fuentes, composición de la agenda informativa, y tipo de encuadre dominante. Tras analizar una muestra de 800 noticias, los resultados indican un aumento progresivo en la cantidad y diversidad de fuentes; una agenda bastante estática y tradicional; y un patrón de encuadre caracterizado por el conflicto y el equilibrio entre lo temático y lo episódico.In news coverage, the cover of press reference represents a very important subject of study. From a longitudinal analysis, the aim of this article is to examine the evolution of three crucial journalistic issues: sources management, media agenda composition, and dominant framing type. After analyzing a sample of 800 news, results indicate a progressive increase in the number and diversity of sources; an agenda rather static and traditional; and a framing pattern characterized by conflict and balance between the thematic and episodic
Superposition rules and stochastic Lie-Scheffers systems
This paper proves a version for stochastic differential equations of the
Lie-Scheffers Theorem. This result characterizes the existence of nonlinear
superposition rules for the general solution of those equations in terms of the
involution properties of the distribution generated by the vector fields that
define it. When stated in the particular case of standard deterministic
systems, our main theorem improves various aspects of the classical
Lie-Scheffers result. We show that the stochastic analog of the classical
Lie-Scheffers systems can be reduced to the study of Lie group valued
stochastic Lie-Scheffers systems; those systems, as well as those taking values
in homogeneous spaces are studied in detail. The developments of the paper are
illustrated with several examples
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