Resilient random modulo cache memories for probabilistically-analyzable real-time systems

Fault tolerance has often been assessed separately in safety-related real-time systems, which may lead to inefficient solutions. Recently, Measurement-Based Probabilistic Timing Analysis (MBPTA) has been proposed to estimate Worst-Case Execution Time (WCET) on high performance hardware. The intrinsic probabilistic nature of MBPTA-commpliant hardware matches perfectly with the random nature of hardware faults. Joint WCET analysis and reliability assessment has been done so far for some MBPTA-compliant designs, but not for the most promising cache design: random modulo. In this paper we perform, for the first time, an assessment of the aging-robustness of random modulo and propose new implementations preserving the key properties of random modulo, a.k.a. low critical path impact, low miss rates and MBPTA compliance, while enhancing reliability in front of aging by achieving a better – yet random – activity distribution across cache sets.Peer ReviewedPostprint (author's final draft

Estimating adaptive setpoint temperatures using weather stations

Reducing both the energy consumption and CO 2 emissions of buildings is nowadays one of the main objectives of society. The use of heating and cooling equipment is among the main causes of energy consumption. Therefore, reducing their consumption guarantees such a goal. In this context, the use of adaptive setpoint temperatures allows such energy consumption to be significantly decreased. However, having reliable data from an external temperature probe is not always possible due to various factors. This research studies the estimation of such temperatures without using external temperature probes. For this purpose, a methodology which consists of collecting data from 10 weather stations of Galicia is carried out, and prediction models (multivariable linear regression (MLR) and multilayer perceptron (MLP)) are applied based on two approaches: (1) using both the setpoint temperature and the mean daily external temperature from the previous day; and (2) using the mean daily external temperature from the previous 7 days. Both prediction models provide adequate performances for approach 1, obtaining accurate results between 1 month (MLR) and 5 months (MLP). However, for approach 2, only the MLP obtained accurate results from the 6th month. This research ensures the continuity of using adaptive setpoint temperatures even in case of possible measurement errors or failures of the external temperature probes.Spanish Ministry of Science, Innovation and Universities 00064742/ITC-20133094Spanish Ministry of Economy, Industry and Competitiveness BIA 2017-85657-

Improving early design stage timing modeling in multicore based real-time systems

This paper presents a modelling approach for the timing behavior of real-time embedded systems (RTES) in early design phases. The model focuses on multicore processors - accepted as the next computing platform for RTES - and in particular it predicts the contention tasks suffer in the access to multicore on-chip shared resources. The model presents the key properties of not requiring the application's source code or binary and having high-accuracy and low overhead. The former is of paramount importance in those common scenarios in which several software suppliers work in parallel implementing different applications for a system integrator, subject to different intellectual property (IP) constraints. Our model helps reducing the risk of exceeding the assigned budgets for each application in late design stages and its associated costs.This work has received funding from the European Space Agency under Project Reference AO=17722=13=NL=LvH, and has also been supported by the Spanish Ministry of Science and Innovation grant TIN2015-65316-P. Jaume Abella has been partially supported by the MINECO under Ramon y Cajal postdoctoral fellowship number RYC-2013-14717.Peer ReviewedPostprint (author's final draft

Arqueologia Subaquática – Dez anos de Convenção da Unesco para a Protecção do Património Cultural Subaquático

Introdução à sessão de Arqueologia Subaquática do JIA-2011, em Faro

El comportamiento de las FARC tras la firma de los acuerdos de La Habana

Resumen. La coyuntura producida con ocasión de la convergencia de múltiples hechos clave en el proceso de paz colombiano (tales como la firma del Acuerdo final para la terminación del conflicto y la construcción de una paz estable y duradera, el polémico plebiscito sobre los acuerdos de paz de Colombia en 2016 y la transformación del grupo insurgente Fuerzas Armadas Revolucionarias de Colombia en Fuerza Alternativa Revolucionaria del Común) plantea la necesidad de revisar los cambios en las estrategias de los actores de dicho proceso. Conforme a esto, el presente artículo propone un análisis cualitativo de la evolución del comportamiento estratégico de las FARC, a la luz de los desarrollos conceptuales de la teoría de la fertilidad revolucionaria, en la cual se toma como base la construcción de un modelo con cuatro variables de estudio. La revisión desde dicho modelo permite observar que la guerrilla continúa su proceso de adaptación e inserción estratégica.Abstract. The conjuncture produced by the convergence of multiple key events in the Colombian peace process, such as the signing of the final agreement ending the conflict and building a stable and lasting peace, the controversial plebiscite on the Colombian peace agreements in 2016, and the transformation of the insurgent Revolutionary Armed Forces of Colombia (FARC) into the Common Alternative Revolutionary Force arouse the need to review the changes in strategy of the actors of this process. Accordingly, this article proposes a qualitative analysis of the evolution of the FARC's strategic behavior, in light of the conceptual developments of the theory of revolutionary fertility, which is based on the construction of a model with four study variables. The review from this model reveals that the guerrillas continue their process of adaptation and strategic insertion

Student perspective about traditional process and formative evaluation: group contrasts in the same subjects

Este estudio, con una muestra de 357 alumnos de 4 asignaturas de la Universidad de Burgos (España), contrasta la percepción que tiene el alumnado acerca de la evaluación que ha recibido, incidiendo en la dificultad encontrada en el proceso y el nivel de implicación y seguimiento realizado. En cada asignatura, un grupo ha sido evaluado mediante un sistema tradicional y otro mediante evaluación formativa. El cuestionario utilizado ha sido la escala de sistemas de evaluación sobre formación inicial. La metodología de trabajo ha sido cuantitativa, empleándose tanto un análisis descriptivo (porcentajes) como inferencial (tablas de contingencia y χ2) en función de los factores extraídos. Los resultados reflejan una percepción más favorable en los grupos que han recibido una evaluación formativa, reconociendo que el sistema es más complejo pero que permite una mayor retroalimentación con el docente, lo que repercute en una mayor implicación y un aprendizaje más significativoThis study, with a sample of 357 students in 4 subjects at the University of Burgos (Spain), contrasts the perception of students about the assessment received, focusing on the difficulties encountered in the process and the level of involvement and monitoring performed. In each subject, a group has been evaluated using a traditional and another system using formative assessment. The questionnaire used was the scale of assessment systems on initial training. The working methodology was quantitative, using both a descriptive analysis (percentages) and inferential (contingency tables and χ2) depending on the extracted factors. The results reflect a more favorable perception in the groups that received a formative assessment, recognizing that the system is more complex but allows more feedback to the teacher, which results in greater involvement and a more meaningful learnin

El Patrimonio Cultural Subacuático, un tesoro de todos y para todos. Arqueología Subacuática y participación social en la protección del PCS

Introdução á sessão de Património Cultural Subaquático do JIA 2012, Santiago de Compostel

Aging in binary-state models: The Threshold model for Complex Contagion

Binary-state models are those in which the constituent elements can only appear in two possible configurations. These models are fundamental in the mathematical treatment of a number of phenomena such as spin interactions in magnetism, opinion dynamics, rumor and information spreading in social systems, etc. Here, we focus on the study of non-Markovian effects associated with aging for binary-state dynamics in complex networks. Aging is considered as the property of the agents to be less prone to change state the longer they have been in the current state, which gives rise to heterogeneous activity patterns. We analyze in this context the Threshold model of Complex Contagion, which has been proposed to explain, for instance, processes of adoption of new technologies and in which the agents need the reiterated confirmation of several contacts (until reaching over a given neighbor fraction threshold) to change state. Our analytical approximations give a good description of extensive numerical simulations in Erd\"os-R\'enyi, random-regular and Barab\'asi-Albert networks. While aging does not modify the spreading condition, it slows down the cascade dynamics towards the full-adoption state: the exponential increase of adopters in time from the original model is replaced by a stretched exponential or power-law, depending on the aging mechanism. Under several approximations, we give analytical expressions for the cascade condition and for the exponents of the exponential, power-law and stretched exponential growth laws for the adopters density. Beyond networks, we also describe by numerical simulations the effects of aging for the Threshold model in a two-dimensional lattice.Comment: 12 pages, 9 figure