GRASP Heuristics for the stochastic weighted graph fragmentation problem

Critical nodes play a major role in network connectivity. Identifying them is important to design efficient strategies to prevent malware or epidemics spread through a network. In this context, the Stochastic Weighted Graph Fragmentation Problem (SWGFP) is a combinatorial optimization problem that b...

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Detalhes bibliográficos
Autor: Rosenstock Cukrowicz, Nicole
Formato: tesis de maestría
Estado:Versión aceptada para publicación
Fecha de publicación:2018
País:Uruguay
Recursos:Universidad de la República
Repositorio:COLIBRI
Idioma:español
OAI Identifier:oai:colibri.udelar.edu.uy:20.500.12008/22384
Acesso em linha:https://hdl.handle.net/20.500.12008/22384
Access Level:acceso abierto
Palavra-chave:Optimización combinatoria
Nodos críticos
GRASP
Complejidad computacional
Path Relinking
COMPLEJIDAD COMPUTACIONAL
Descrição
Resumo:Critical nodes play a major role in network connectivity. Identifying them is important to design efficient strategies to prevent malware or epidemics spread through a network. In this context, the Stochastic Weighted Graph Fragmentation Problem (SWGFP) is a combinatorial optimization problem that belongs to the N P − Complete class. Its objective consists in minimizing the impact of a random attack on a singleton, choosing appropiately a set of nodes to immunize given a restricted budget. In the SWGFP, it is assumed that the attack follows a known probability law and that it affects the whole connected component of the attacked node. In this thesis, a GRASP enriched with Path Relinking algorithm is developed to solve the SWGFP. Its performance is studied under three attack scenarios and compared with a GRASP variant that was previously developed in literature and with a Random heuristic for the problem that picks a set of nodes uniformly at random. Computational experiments show that the algorithm based on Independent Sets which is developed in this thesis, outperforms the other two, with lower expected loss scores and higher robustness.