46 research outputs found

    Risk analysis sampling methods in terrorist networks based on the Banzhaf value

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    This article introduces the Banzhaf and the Banzhaf鈥揙wen values as novel measures of risk analysis of a terrorist attack, determining the most dangerous terrorists in a network. This new approach counts with the advantage of integrating at the same time the complete topology (i.e., nodes and edges) of the network and a coalitional structure on the nodes of the network. More precisely, the characteristics of the nodes (e.g., terrorists) of the network and their possible relationships (e.g., types of communication links), as well as coalitional information (e.g., level of hierarchies) independent of the network. First, for these two new measures of risk analysis, we provide and implement approximation algorithms. Second, as illustration, we rank the members of the Zerkani network, responsible for the attacks in Paris (2015) and Brussels (2016). Finally, we give a comparison between the rankings established by the Banzhaf and the Banzhaf鈥揙wen values as measures of risk analysisMinisterio de Ciencia e Innovaci贸n, Grant/Award Numbers: PGC2018-097965-B-I00, PID2021-124030NB-C32; Xunta de Galicia, Grant/Award Number: ED431C 2021/24; Ministerio de Ciencia, Innovaci贸n y Universidades, Grant/Award Number: MTM2017-87197-C3-3-PS

    Node aggregation for enhancing PageRank

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    In this paper, we study the problem of node aggregation under different perspectives for increasing PageRank of some nodes of interest. PageRank is one of the parameters used by the search engine Google to determine the relevance of a web page. We focus our attention to the problem of nding the best nodes in the network from an aggregation viewpoint, i.e., what are the best nodes to merge with for the given nodes. This problem is studied from global and local perspectives. Approximations are proposed to reduce the computation burden and to overcome the limitations resulting from the lack of centralized information. Several examples are presented to illustrate the different approaches that we proposeFP7-ICT Project DYMASOS under Grant 611281Ministerio de Econom铆a y Competitividad COOPERA Project Grant DPI2013-46912-C2-1-RMinisterio de Educaci贸n Jos茅 Castillejo Grant (CAS14/00277)Grant-in-Aid for Scientific Research Grant 15H04020 and Fellowship PE1604

    Railway Rapid Transit timetables with variable and elastic demand.

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    This paper focuses on the design of railway timetables considering a variable elastic demand profile along a whole design day. Timetabling is the third stage in the classical hierarchical railway planning process. Most of previous works on this topic consider a uniform demand behavior for short planning intervals. In this paper, we propose a MINLP model for designing non-periodic timetables on a railway corridor where demand is dependent on waiting times. In the elastic demand case, long waiting times lead to a loss of passengers, who may select an alternative transportation mode. The mode choice is modeled using two alternative methods. The first one is based on a sigmoid function and can be used in case of absence of information for competitor modes. In the second one, the mode choice probability is obtained using a Logit model that explicitly considers the existence of a main alternative mode. With the purpose of obtaining optimal departure times, in both cases, a minimization of the loss of passengers is used as objective function. Finally, as illustration, the timetabling MINLP model with both mode choice methods is applied to a real case and computational results are shown

    El poder de las naciones en la Uni贸n Europea

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    En este trabajo se definen algoritmos, basados en funciones generatrices, para calcular el 铆ndice de poder de Banzhaf en juegos simples de votaci贸n ponderada y en juegos de doble y triple mayor铆a. La utilizaci贸n de funciones generatrices permite un c谩lculo exacto del 铆ndice de Banzhaf con una reducci贸n sensible de la complejidad temporal. Adem谩s se calculan los 铆ndices de Banzhaf para las reglas de decisi贸n, aprobadas en la cumbre de Niza, que se utilizan en la Uni贸n Europea ampliada a 25 pa铆ses. Finalmente, se demuestra que los sistemas de triple mayor铆a adoptados son equivalentes en la pr谩ctica a juegos de mayor铆a simple o doble, porque la cuota de poblaci贸n exigida para aprobar una decisi贸n no cambia el 铆ndice de Banzhaf de los pa铆ses de la Uni贸n Europea ampliada.Juegos de votaci贸n; 铆ndice de Banzhaf; Uni贸n Europea

    Multi-issue bankruptcy problems with crossed claims

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    In this paper, we introduce a novel model of multi-issue bankruptcy problem inspired from a real problem of abatement of emissions of different pollutants in which pollutants can have more than one effect on atmosphere. In our model, therefore, several perfectly divisible goods (estates) have to be allocated among certain set of agents (claimants) that have exactly one claim which is used in all estates simultaneously. In other words, unlike of the multi-issue bankruptcy problems already existent in the literature, this model study situations with multi- dimensional states, one for each issue and where each agent claims the same to the different issues in which participates. In this context, we present an allocation rule that generalizes the well-known constrained equal awards rule from a procedure derived from analyzing this rule for classical bankruptcy problems as the solution to a sucession of linear programming problems. Next, we carry out an study of its main properties, and we characterize it using the well-known property of consistency

    An iterative design method for Coalitional control networks with constraints on the shapley Value

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    9th World CongressThe International Federation of Automatic ControlCape Town, South Africa. August 24-29In this work, we introduce a new iterative design method for a coalitional control scheme for linear systems recently proposed. In this scheme, the links in the network infrastructure are enabled or disabled depending on their contribution to the overall system performance. As a consequence, the local controllers are divided dynamically into sets or coalitions that cooperate in order to attain their control tasks. The new design method allows the control system designer to include new constraints regarding the game theoretical tools of the control architecture, while optimizing the matrices that define the controller

    On priority in multi-issue bankruptcy problems with crossed claims

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    In this paper, we analyze the problem of how to adapt the concept of priority to situations where several perfectly divisible resources have to be allocated among certain set of agents that have exactly one claim which is used for all resources. In particular, we introduce constrained sequential priority rules and two constrained random arrival rules, which extend the classical sequential priority rules and the random arrival rule to these situations. Moreover, we provide an axiomatic analysis of these rules.Comment: 12 pages. arXiv admin note: substantial text overlap with arXiv:2202.0987

    Preface: SING 14

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    An Application of Cooperative Game Theory to Distributed Control

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    18th World CongressThe International Federation of Automatic ControlMilano (Italy) August 28 - September 2, 2011In this paper we propose to study the underlying properties of a given distributed control scheme in which a set of agents switch between different communication strategies that define which network links are used in order to regulate to the origin a set of unconstrained linear systems. The problems of how to decide the time-varying communication strategy, share the benefits/costs and detect which are the most critical links in the network are solved using tools from game theory. The proposed scheme is demonstrated through a simulation example
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