Probabilistic memory-one strategies to dominate the iterated prisoner’s dilemma over networks

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGThe Iterated Prisoner’s Dilemma (IPD) has been a classical game theoretical scenario used to model behaviour interactions among agents. From the famous Axelrod’s tournament, and the successful results obtained by the Tit for Tat strategy, to the introduction of the zerodeterminant strategies in the last decade, the game theory community has been exploring the performance of multiple strategies for years. This article grounds on such previous work, studying probabilistic memory-one strategies (PMO) and using evolutionary game theory, to analyse the criteria to find the most successful set of strategies in networked topologies. The results are nearly deterministic in discrete PMO scenarios. However, results become much more complex when moving to continuous ones, and there is no optimal strategy for a given scenario. Finally, this article describes how, using machine learning and evolutionary techniques; a cluster of agents, playing synchronously and adaptively, is able to dominate the rest of the populatio

NUMERICAL SOLUTION OF A TIME-DEPENDENT SIGNORINI CONTACT PROBLEM

International audienceThe purpose of this work is to study the dynamic frictionless contact problem between an elastic body and a rigid foundation. In order to model the contact we consider Signorini conditions. A numerical algorithm is proposed to approximate the solution; the algorithm involves a contact multi-plier, which is a fixed point of a nonlinear equation solved by using a generalized Newton method. We use one of the Newmark methods for time discretization and a finite element method for space discretization. The convergence of the method is numerically studied, and a simple test problem is used to validate the methodology

Confirmación de la presencia de Allonyx quadrimaculatus (Schaller, 1783) (Coleoptera, Cleridae) en Galicia (N.O. de la Península Ibérica)

The occurrence of Allonyx quadrimaculatus (Schaller, 1783) (Coleoptera: Cleridae) in Galicia (NW Spain) is confirmed and its distribution is also commented, both at Iberian and European levelSe confirma la presencia de Allonyx quadrimaculatus (Schaller, 1783) (Coleoptera: Cleridae) en Galicia (NO España) y también se comenta su distribución, tanto a nivel ibérico como europeo

An applied method for assessing socioeconomic impacts of European fisheries quota-based management

Fishing activity is conditioned by diverse factors that determine and limit the capacity of fishermen to decide on their level of production (i.e., the fisheries output is determined exogenously). In the context of the input-output analysis, models have been developed that permit the assessment of socioeconomic impacts of an activity, but almost always from a perspective where demand is the driving force of the economy. Procedures have recently been developed to measure impacts in which both the existence of sectors subject to exogenous supply shocks and the existence of forward linkages with other sectors of the same economy are considered. The objective of this study is the application of this new methodology for the analysis of a specific case: fishing activity in Galicia (NW Spain). The socioeconomic impacts linked to the determination of annual fishing quotas by species for major fleet segments managed by European Union are quantified. This procedure is should be potentially be very useful as a fishing management tool. It provides more accurate estimations of the possible socioeconomic impacts of catch limitations and gives detailed information on the sectoral and spatial distribution of these impacts on the economy.Xunta de Galicia | Ref. GRC2014/022Xunta de Galicia | Ref. AGRUP2015/08Ministerio de Economía y Competitividad | Ref. ECO2014-52412-

Characterization of fisheries dependence in Galicia (Spain)

The management of marine ecosystems requires adequate knowledge of both environmental and human dimensions, as well as their interrelationships. In this study, the aquaculture and fisheries activities are analyzed in one of most important fishing regions in Europe, Galicia (NW Spain). In particular, the intensity and characteristics of the fishing dependency are evaluated in terms of income and employment. Thus, nine marine economic activities for nine Maritime Zones have been defined, considering the social and economic relevance of the provided ecosystem services to these communities. This paper highlights the entire Galician coast as fishing-dependent, independently of the urbanization level. Furthermore, the contribution of different fishery segments to the income and employment of these coastal communities is reviewed, including fluctuations on whether the activity is small or large-scale. Finally, this study establishes a strong relationship among the marine activities, which generate most employment, and the regulatory framework of the Regional Government. Therefore, the conclusions are relevant to design and implement policies that affect Galicia׳s Region and all its related marine ecosystems.Xunta de Galicia | Ref. CN 2011/020Ministerio de Ciencia e Innovación | Ref. ECO2009-1032

A methodological approach to quantifying socioeconomic impacts linked to supply shocks

Input-output models are commonly used to assess socioeconomic impacts. These models typically evaluate exogenous variations in demand-related elements; however, they do not fully capture the associated effects of backward and forward sectoral linkages simultaneously. An analysis from the supply perspective is of greater interest to economic sectors that exploit natural resources because their activity is subject to natural variations or political factors beyond the producers' direct control. This paper proposes a methodology to improve the estimation of the impacts of these variations or supply shocks. Within the methodological context of input-output analysis, a practical procedure is introduced including price mechanisms that allow us to consider all sectoral linkages (backward and forward). Therefore, the proposed method will improve impact assessments derived from supply shocks linked to environmental events.Ministerio de Economía y Competitividad | Ref. ECO2014-52412-RXunta de Galicia | Ref. GRC2014/022Xunta de Galicia | Ref. AGRUP2015/0

Assessment of Socioeconomic Impacts Through Physical Multipliers: The Case of Fishing Activity in Galicia (Spain)

In the context of fishery management based on the ecosystem-based approach, it is necessary to develop methods and tools in order to facilitate the decision making and balance the socioeconomic and environmental dimensions of sustainability. The goal of this document consists of providing an assessment tool of the possible socioeconomic impacts arising from the variation in the fishing opportunities. After defining what we call input-output physical multipliers, an application for the case of fishing in Galicia (Spain) was developed. The results show that this method is valid for obtaining a more accurate assessment of the possible socioeconomic impacts arising from a fishing supply shock, considering in equal measure the backward and forward linkages of fishing activity with other sectors. The defined multipliers permit the assessment and comparison ex ante of different management scenarios for fisheries. As a consequence, this is a method with the capacity to provide support for a better decision making to the fishery regulators and other decision-makers, facilitating the implementation of more holistic management frameworks

Reduced density matrices in molecular systems: Grand-canonical electron states

Grand-canonical like descriptions of many electron atomic and molecular open systems which are characterized by a non-integer number of electrons are presented. Their associated reduced density matrices (RDMs) are obtained by introducing the contracting mapping for this type of distributions. It is shown that there is loss of information when connecting RDMs of different order by partial contractions. The energy convexity property of these systems simplifies the description. Consequently, this formulation opens the possibility to a new look for chemical descriptors such as chemical potential and reactivity among others. Examples are presented to discuss the theoretical aspects of this work.Fil: Bochicchio, Roberto Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física; ArgentinaFil: Miranda Quintana, Ramón A.. Universidad de La Habana. Facultad de Química. Laboratorio de Química Computacional y Teórica; CubaFil: Rial, Diego Fernando. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Instituto de Investigaciones Matematicas

Interpretable Classification of Wiki-Review Streams

Wiki articles are created and maintained by a crowd of editors, producing a continuous stream of reviews. Reviews can take the form of additions, reverts, or both. This crowdsourcing model is exposed to manipulation since neither reviews nor editors are automatically screened and purged. To protect articles against vandalism or damage, the stream of reviews can be mined to classify reviews and profile editors in real-time. The goal of this work is to anticipate and explain which reviews to revert. This way, editors are informed why their edits will be reverted. The proposed method employs stream-based processing, updating the profiling and classification models on each incoming event. The profiling uses side and content-based features employing Natural Language Processing, and editor profiles are incrementally updated based on their reviews. Since the proposed method relies on self-explainable classification algorithms, it is possible to understand why a review has been classified as a revert or a non-revert. In addition, this work contributes an algorithm for generating synthetic data for class balancing, making the final classification fairer. The proposed online method was tested with a real data set from Wikivoyage, which was balanced through the aforementioned synthetic data generation. The results attained near-90 % values for all evaluation metrics (accuracy, precision, recall, and F-measure).info:eu-repo/semantics/publishedVersio

The Effect of Relative Age on Participation in the National Sports Training Plan and the Achievement of Sporting Success in Canoeing

El objetivo principal del presente trabajo ha sido identificar, en función del trimestre del año en el que se ha nacido, la proporción de piragüistas de aguas tranquilas que forman parte del Plan nacional de tecnificación deportiva (PNTD) de la Real Federación Española de Piragüismo (RFEP) y los que obtienen una medalla en los campeonatos del mundo y juegos olímpicos. Se ha analizado el trimestre del año en el que han nacido los 152 piragüistas de 16 años de edad que han sido seleccionados para formar parte de las concentraciones del PNTD de la RFEP entre los años 2009 y 2011, y los 76 piragüistas españoles que hasta la actualidad han obtenido una medalla en los Campeonatos del Mundo y Juegos Olímpicos. Entre los participantes del PNTD prevalecen los nacidos en el primer trimestre (37,5%) (2=18,68; p<0,001). No obstante, al analizar los piragüistas que han sido medallistas en mundiales y Juegos Olímpicos se encuentra que el mayor porcentaje ha nacido en el cuarto trimestre del año (35,1 %) (2 = 13,756; p < 0,05). Por tanto, nacer en el primer trimestre del año es uno de los factores determinantes en la elec- ción de los piragüistas para formar parte del PNTD, pero no en la consecución de éxitos internacionales posteriormente; por lo que deberían restituirse los criterios para elegir a los piragüistas que se incluyen en el PNTD teniendo en cuenta factores como el estado madurativo del sujeto.The main purpose of this study was to identify the proportion of flatwater canoeists who form part of the national sports training plan (PNTD) of the Royal Spanish Canoe Federation (RFEP) and those who win a medal at the World Championships and Olympic Games based on the quarter of the year in which they were born. We analysed the quarter of the year in which the 152 canoeists aged 16 who were selected to be part of the PNTD gatherings of the RFEP between 2009 and 2011 and the 76 Spanish canoeists who have to date won a medal at the World Championships and Olympic Games were born. The largest group of PNTD participants were born in the first quarter (37.5%) (2=18.68; p<0,001). However, when analysing the canoeists who have been medallists at World Championships and the Olympic Games the greatest percentage is for those born in the fourth quarter of the year (35.1%) (2 = 13.756; p < 0,05). Therefore being born in the first quarter of the year is one of the determining factors in selecting canoeists to join the PNTD but not in achieving international successes later on. Hence the criteria for choosing the canoeists to be included in the PNTD should be restored to take into account factors such as the developmental stage of the individual.Actividad Física y Deport