Paulo Boaventura Netto - Academia.edu (original) (raw)
Papers by Paulo Boaventura Netto
This paper presents the results of two explorations: one, exhaustive, of the graph sets from 4 to... more This paper presents the results of two explorations: one, exhaustive, of the graph sets from 4 to 10 vertices, and other, using AGX-III program on graphs from 11 to 30 vertices, both looking for extremal graphs for two new irregularity measures. Some discussions on the obtained results are presented. The involved measures have polynomial complexity.
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Pesquisa Operacional, 2004
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Revista de Matemática: Teoría y Aplicaciones, 2015
This paper presents some measures of graph irregularity found in the literature. From their discu... more This paper presents some measures of graph irregularity found in the literature. From their discussion two important points appear: first, the absence of relationship between all of them, but a single exception, with the structures of the corresponding graphs and, moreover, their known extremal values correspond to graphs having degree sequences with few different values. Two new measures are proposed, seeking to meet these points. Their values are calculated for extremal graphs associated with other measures and for antiregular graphs. Finally, we calculate the boxplots of all these measures for some sets of graphs taken from the literature and also for four sets where the ordered degree sequences are constant. All measures involved have polynomial complexity.
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The definition of a multiple-neighborhood structure on the permutation lattice graph is used in t... more The definition of a multiple-neighborhood structure on the permutation lattice graph is used in the study of a variable neighborhood search (VNS) algorithm applied to the Quadratic Assignment Problem.
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A previous result derived for non-valued graphs is generalized for link-valued ones, thus allowin... more A previous result derived for non-valued graphs is generalized for link-valued ones, thus allowing the determination of the total value of the spanning arborescences with a given root and containing a given arc in a directed valued graph. A corresponding result for non-directed valued graphs is also presented.
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A result based on the matrix-tree theorem allowed us, in a previous work, to associate to a graph... more A result based on the matrix-tree theorem allowed us, in a previous work, to associate to a graph link the value of the spanning arborescences or trees from which it participates, in a directed or undirected valued graph. It is well known that for every combinatorial counting function we can define a corresponding generating function and vice-versa. Using the same techniques of the preceding work, we define a generating function for the above referred subsets of structures and use the result, together with a specific value criterion, to identify and count the linear structures.
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O problema das p -medianas, que consiste em localizar p facilidades (medianas) em uma rede, minim... more O problema das p -medianas, que consiste em localizar p facilidades (medianas) em uma rede, minimizando-se a soma de todas as distâncias de cada ponto de demanda a sua mediana mais proxima, tem sido utilizado como uma ferramenta que auxilia na tomada de decisoes de localizacao. Este estudo busca localizar, atraves deuma heuristica especificamente projetada, um dado numero de unidades urbanas de lazer (largos, pracas, pracas esportivas, pocket parks , bosques e parques municipais), em uma area da regiao norte do Rio de Janeiro. Palavras-chave: p-medianas, Unidades Urbanas de Lazer, grafos.
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Resumo Neste trabalho é abordado o Problema da Alocação Dinâmica de Espaços onde um projeto é div... more Resumo Neste trabalho é abordado o Problema da Alocação Dinâmica de Espaços onde um projeto é dividido por um número de períodos consecutivos e, em cada um deles, uma quantidade de atividades é realizada. Os recursos necessários para as atividades devem estar disponíveis em espaços de trabalho e os recursos ociosos no período devem ser guardados em espaços de armazenamento. Este problema contém o Problema Quadrático de Alocação (PQA) como um caso particular e, portanto, pertence a classe NP-difícil. Neste contexto a dificuldade em encontrar soluções ótimas, mesmo para instâncias de média dimensão, justifica o uso de métodos heurísticos. Este trabalho propõe algoritmos de construção e heurísticas baseados no GRASP e Busca Tabu para a obtenção de soluções aproximadas. Os resultados computacionais obtidos mostram que os métodos propostos são competitivos na resolução das instâncias do problema existentes na literatura. Abstract This work is dedicated to the Dynamic Space Allocation Pro...
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Pesquisa Operacional, 2008
A result based on a classic theorem of graph theory is generalized for edge-valued graphs, allowi... more A result based on a classic theorem of graph theory is generalized for edge-valued graphs, allowing determination of the total value of the spanning arborescences with a given root and containing a given arc in a directed valued graph. A corresponding result for undirected valued graphs is also presented. In both cases, the technique allows for a ranking of the graph edges by importance under this criterion. This ranking is proposed as a tool to determine the relative importance of the edges of a graph in network vulnerability studies. Some examples of application are presented.
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Produção, 1993
Este trabalho consiste numa aplicação das técnicas de modelagem por grafos à geração de seqüência... more Este trabalho consiste numa aplicação das técnicas de modelagem por grafos à geração de seqüências de montagem de um produto discreto (composto de uma série de peças). Utilizamos como referência para o trabalho método desenvolvido por A. Bourjault [5] e T. Fazio e D. Whitney [6].
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A vertex-set covering in a triangulated planar su pport graph is built as a se t of elementary pa... more A vertex-set covering in a triangulated planar su pport graph is built as a se t of elementary paths between pairs of peripherical vertices, with the restriction of maximum degree 4 for the spanning subgraph thus obtained. This structure is what one would need when designing a metro network, where the vertices are the stations and the edges are line
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Computers & Operations Research, 2012
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Given a support planar graph representing points to receive electric charge (charge points) and e... more Given a support planar graph representing points to receive electric charge (charge points) and every possible link able to be built in a real estate region, the objective of this work is the development of a heuristic for generating a least-cost distributiom network taking into account the technical, environmental and operational constraints associated to the problem. For such a situation
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European Journal Operational …, 2007
The quadratic assignment problem (QAP), one of the most difficult problems in the NP-hard class, ... more The quadratic assignment problem (QAP), one of the most difficult problems in the NP-hard class, models many applications in several areas such as operational research, parallel and distributed computing, and combinatorial data analysis. Other optimization combinatorial problems such as the traveling salesman problem, maximal clique, isomorphism and graph partitioning can be formulated as a QAP. In this paper, we survey
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Pesquisa Operacional, 2000
O Problema Quadrático de Alocação (PQA) pertence à classe dos problemas NP-Hard e desafia os pesq... more O Problema Quadrático de Alocação (PQA) pertence à classe dos problemas NP-Hard e desafia os pesquisadores tanto em sua teoria quanto em sua parte computacional. Pela sua alta complexidade muitos métodos heurísticos têm sido desenvolvidos para tentar resolvê-lo aproximadamente. A metaheurística GRASP (greedy randomized adaptive search procedures) se mostrou bastante eficiente. Neste trabalho, uma proposta para descartar soluções iniciais supostamente ruins é apresentada com base na normalização de custos calculadas num intervalo entre limites de solução. Para este GRASP restrito, foi observada uma redução do tempo computacional para encontrar as soluções ótimas ou soluções viáveis de boa qualidade quando comparado ao GRASP original.
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Anais do 10. Congresso Brasileiro de Inteligência Computacional, 2016
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Pesquisa Operacional, 2013
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European Journal of Operational Research, 2007
The quadratic assignment problem (QAP), one of the most difficult problems in the NP-hard class, ... more The quadratic assignment problem (QAP), one of the most difficult problems in the NP-hard class, models many real-life problems in several areas such as facilities location, parallel and distributed computing, and combinatorial data analysis. Combinatorial optimization ...
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This paper presents the results of two explorations: one, exhaustive, of the graph sets from 4 to... more This paper presents the results of two explorations: one, exhaustive, of the graph sets from 4 to 10 vertices, and other, using AGX-III program on graphs from 11 to 30 vertices, both looking for extremal graphs for two new irregularity measures. Some discussions on the obtained results are presented. The involved measures have polynomial complexity.
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Pesquisa Operacional, 2004
Bookmarks Related papers MentionsView impact
Revista de Matemática: Teoría y Aplicaciones, 2015
This paper presents some measures of graph irregularity found in the literature. From their discu... more This paper presents some measures of graph irregularity found in the literature. From their discussion two important points appear: first, the absence of relationship between all of them, but a single exception, with the structures of the corresponding graphs and, moreover, their known extremal values correspond to graphs having degree sequences with few different values. Two new measures are proposed, seeking to meet these points. Their values are calculated for extremal graphs associated with other measures and for antiregular graphs. Finally, we calculate the boxplots of all these measures for some sets of graphs taken from the literature and also for four sets where the ordered degree sequences are constant. All measures involved have polynomial complexity.
Bookmarks Related papers MentionsView impact
The definition of a multiple-neighborhood structure on the permutation lattice graph is used in t... more The definition of a multiple-neighborhood structure on the permutation lattice graph is used in the study of a variable neighborhood search (VNS) algorithm applied to the Quadratic Assignment Problem.
Bookmarks Related papers MentionsView impact
A previous result derived for non-valued graphs is generalized for link-valued ones, thus allowin... more A previous result derived for non-valued graphs is generalized for link-valued ones, thus allowing the determination of the total value of the spanning arborescences with a given root and containing a given arc in a directed valued graph. A corresponding result for non-directed valued graphs is also presented.
Bookmarks Related papers MentionsView impact
A result based on the matrix-tree theorem allowed us, in a previous work, to associate to a graph... more A result based on the matrix-tree theorem allowed us, in a previous work, to associate to a graph link the value of the spanning arborescences or trees from which it participates, in a directed or undirected valued graph. It is well known that for every combinatorial counting function we can define a corresponding generating function and vice-versa. Using the same techniques of the preceding work, we define a generating function for the above referred subsets of structures and use the result, together with a specific value criterion, to identify and count the linear structures.
Bookmarks Related papers MentionsView impact
O problema das p -medianas, que consiste em localizar p facilidades (medianas) em uma rede, minim... more O problema das p -medianas, que consiste em localizar p facilidades (medianas) em uma rede, minimizando-se a soma de todas as distâncias de cada ponto de demanda a sua mediana mais proxima, tem sido utilizado como uma ferramenta que auxilia na tomada de decisoes de localizacao. Este estudo busca localizar, atraves deuma heuristica especificamente projetada, um dado numero de unidades urbanas de lazer (largos, pracas, pracas esportivas, pocket parks , bosques e parques municipais), em uma area da regiao norte do Rio de Janeiro. Palavras-chave: p-medianas, Unidades Urbanas de Lazer, grafos.
Bookmarks Related papers MentionsView impact
Resumo Neste trabalho é abordado o Problema da Alocação Dinâmica de Espaços onde um projeto é div... more Resumo Neste trabalho é abordado o Problema da Alocação Dinâmica de Espaços onde um projeto é dividido por um número de períodos consecutivos e, em cada um deles, uma quantidade de atividades é realizada. Os recursos necessários para as atividades devem estar disponíveis em espaços de trabalho e os recursos ociosos no período devem ser guardados em espaços de armazenamento. Este problema contém o Problema Quadrático de Alocação (PQA) como um caso particular e, portanto, pertence a classe NP-difícil. Neste contexto a dificuldade em encontrar soluções ótimas, mesmo para instâncias de média dimensão, justifica o uso de métodos heurísticos. Este trabalho propõe algoritmos de construção e heurísticas baseados no GRASP e Busca Tabu para a obtenção de soluções aproximadas. Os resultados computacionais obtidos mostram que os métodos propostos são competitivos na resolução das instâncias do problema existentes na literatura. Abstract This work is dedicated to the Dynamic Space Allocation Pro...
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Pesquisa Operacional, 2008
A result based on a classic theorem of graph theory is generalized for edge-valued graphs, allowi... more A result based on a classic theorem of graph theory is generalized for edge-valued graphs, allowing determination of the total value of the spanning arborescences with a given root and containing a given arc in a directed valued graph. A corresponding result for undirected valued graphs is also presented. In both cases, the technique allows for a ranking of the graph edges by importance under this criterion. This ranking is proposed as a tool to determine the relative importance of the edges of a graph in network vulnerability studies. Some examples of application are presented.
Bookmarks Related papers MentionsView impact
Produção, 1993
Este trabalho consiste numa aplicação das técnicas de modelagem por grafos à geração de seqüência... more Este trabalho consiste numa aplicação das técnicas de modelagem por grafos à geração de seqüências de montagem de um produto discreto (composto de uma série de peças). Utilizamos como referência para o trabalho método desenvolvido por A. Bourjault [5] e T. Fazio e D. Whitney [6].
Bookmarks Related papers MentionsView impact
A vertex-set covering in a triangulated planar su pport graph is built as a se t of elementary pa... more A vertex-set covering in a triangulated planar su pport graph is built as a se t of elementary paths between pairs of peripherical vertices, with the restriction of maximum degree 4 for the spanning subgraph thus obtained. This structure is what one would need when designing a metro network, where the vertices are the stations and the edges are line
Bookmarks Related papers MentionsView impact
Computers & Operations Research, 2012
Bookmarks Related papers MentionsView impact
Given a support planar graph representing points to receive electric charge (charge points) and e... more Given a support planar graph representing points to receive electric charge (charge points) and every possible link able to be built in a real estate region, the objective of this work is the development of a heuristic for generating a least-cost distributiom network taking into account the technical, environmental and operational constraints associated to the problem. For such a situation
Bookmarks Related papers MentionsView impact
European Journal Operational …, 2007
The quadratic assignment problem (QAP), one of the most difficult problems in the NP-hard class, ... more The quadratic assignment problem (QAP), one of the most difficult problems in the NP-hard class, models many applications in several areas such as operational research, parallel and distributed computing, and combinatorial data analysis. Other optimization combinatorial problems such as the traveling salesman problem, maximal clique, isomorphism and graph partitioning can be formulated as a QAP. In this paper, we survey
Bookmarks Related papers MentionsView impact
Pesquisa Operacional, 2000
O Problema Quadrático de Alocação (PQA) pertence à classe dos problemas NP-Hard e desafia os pesq... more O Problema Quadrático de Alocação (PQA) pertence à classe dos problemas NP-Hard e desafia os pesquisadores tanto em sua teoria quanto em sua parte computacional. Pela sua alta complexidade muitos métodos heurísticos têm sido desenvolvidos para tentar resolvê-lo aproximadamente. A metaheurística GRASP (greedy randomized adaptive search procedures) se mostrou bastante eficiente. Neste trabalho, uma proposta para descartar soluções iniciais supostamente ruins é apresentada com base na normalização de custos calculadas num intervalo entre limites de solução. Para este GRASP restrito, foi observada uma redução do tempo computacional para encontrar as soluções ótimas ou soluções viáveis de boa qualidade quando comparado ao GRASP original.
Bookmarks Related papers MentionsView impact
Anais do 10. Congresso Brasileiro de Inteligência Computacional, 2016
Bookmarks Related papers MentionsView impact
Pesquisa Operacional, 2013
Bookmarks Related papers MentionsView impact
European Journal of Operational Research, 2007
The quadratic assignment problem (QAP), one of the most difficult problems in the NP-hard class, ... more The quadratic assignment problem (QAP), one of the most difficult problems in the NP-hard class, models many real-life problems in several areas such as facilities location, parallel and distributed computing, and combinatorial data analysis. Combinatorial optimization ...
Bookmarks Related papers MentionsView impact