Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2018-10-30T11:09:54Z No. of bitstreams: 2 Dissertação - Braully Rocha da Silva - 2018.pdf: 1396149 bytes, checksum: 9a9145cb07e037a784d2d15d43cbd1ff (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-10-30T11:20:36Z (GMT) No. of bitstreams: 2 Dissertação - Braully Rocha da Silva - 2018.pdf: 1396149 bytes, checksum: 9a9145cb07e037a784d2d15d43cbd1ff (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-10-30T11:20:36Z (GMT). No. of bitstreams: 2 Dissertação - Braully Rocha da Silva - 2018.pdf: 1396149 bytes, checksum: 9a9145cb07e037a784d2d15d43cbd1ff (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-09-24 / Outro / In this work we present results and implementantions for hull and Carathéodory numbers in P3 convexity. We obtain results for graphs of diameter 2 having cut-vertex for both problems. Finally, entering more complex cases, we were able to determine a logarithmic limit, means of algorithm, for the hull number in case of graph diameter 2 and 2-connected. Exploring more restrictive cases, we determined a constant limit for some subclasses of graphs of diameter 2. We made also implementations and algorithms for these parameters. Implementations algorithms heuristic, parallel, and brute force. Finally, although not directly related, we developed an algorithm for Moore's graphs generation, which may be one of the ways to find Moore missinge graph, if it exists, a question that remains unknown for 55 years. And finally, we conclude with some conjectures interesting, for limits to the hull and Carathéodory numbers, in other classes of graphs, that were not explored in this work, but was identified by the implementations, and can be better explored in future works. / Nesta dissertação, tratamos de limites para o número envoltório e o número de Carathéodory na Convexidade P3. Aferimos resultados para grafos de diâmetro 2 com vértice de corte para ambos os problemas. Adentrando em casos mais complexos, conseguimos determinar um limite logarítmico, por meio de algoritmo pseudo-polimonial, para o número envoltório de grafos de diâmetro 2 biconexos. Explorando um pouco mais restritivamente, conseguimos determinar um limite constante para algumas subclasses de grafos de diâmetro 2, os grafos maximais sem triângulo. Não atendo somente aos resultados teóricos, realizamos também implementações e algoritmos para esses parâmetros. As implementações perfazem algoritmos heurísticos, paralelos e força bruta. Por fim, embora não diretamente relacionado, desenvolvemos uma algoritmo para geração de grafos de Moore, que pode ser um dos caminhos para encontrar o ultimo grafo de Moore, caso ele exista. Questão que remanesce desconhecido e procurada por 55 anos.

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / In this dissertation we present complexity results related to the hull number and the convexity number for P3 convexity. We show that the hull number and the convexity number are NP-hard even for bipartite graphs. Inspired by our research in convexity based on paths, we introduce a new convexity, where we defined as convexity of induced paths of order three or P∗ 3 . We show a relation between the geodetic convexity and the P∗ 3 convexity when the graph is a join of a Km with a non-complete graph. We did research in geometric convexity and from that we characterized graph classes under some convexities such as the star florest in P3 convexity, chordal cographs in P∗ 3 convexity, and the florests in TP convexity. We also demonstrated convexities that are geometric only in specific graph classes such as cographs in P4+-free convexity, F free graphs in F-free convexity and others. Finally, we demonstrated some results of geodesic convexity and P∗ 3 in graphs with few P4âs. / In this dissertation we present complexity results related to the hull number and the convexity number for P3 convexity. We show that the hull number and the convexity number are NP-hard even for bipartite graphs. Inspired by our research in convexity based on paths, we introduce a new convexity, where we defined as convexity of induced paths of order three or P∗ 3 . We show a relation between the geodetic convexity and the P∗ 3 convexity when the graph is a join of a Km with a non-complete graph. We did research in geometric convexity and from that we characterized graph classes under some convexities such as the star florest in P3 convexity, chordal cographs in P∗ 3 convexity, and the florests in TP convexity. We also demonstrated convexities that are geometric only in specific graph classes such as cographs in P4+-free convexity, F free graphs in F-free convexity and others. Finally, we demonstrated some results of geodesic convexity and P∗ 3 in graphs with few P4âs.

Submitted by JÚLIO HEBER SILVA (julioheber@yahoo.com.br) on 2016-12-09T16:43:52Z No. of bitstreams: 2 Dissertação - Julliano Rosa Nascimento - 2016.pdf: 1812313 bytes, checksum: 9bdaa6ddbbe1dd9ce1e9ccdea8016eaf (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Jaqueline Silva (jtas29@gmail.com) on 2016-12-13T19:11:50Z (GMT) No. of bitstreams: 2 Dissertação - Julliano Rosa Nascimento - 2016.pdf: 1812313 bytes, checksum: 9bdaa6ddbbe1dd9ce1e9ccdea8016eaf (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-12-13T19:11:50Z (GMT). No. of bitstreams: 2 Dissertação - Julliano Rosa Nascimento - 2016.pdf: 1812313 bytes, checksum: 9bdaa6ddbbe1dd9ce1e9ccdea8016eaf (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-11-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this work, we consider the parameter hull number in two graph convexities, the P3- convexity and the geodetic convexity. In the P3-convexity, we present results on the P3- hull number on the Cartesian product, strong product and lexicographic product of graphs. In special, regarding to the Cartesian product, we proved a complexity result, in which we show, given a graph G resulting of a Cartesian product of two graphs and a positive integer k, is NP-complete to decide whether the P3-hull number of G is less than or equal k. We also consider the P3-hull number on complementary prisms GG of connected graphs G and G, in which we show a tighter upper bound than that found in the literature. In the geodetic convexity, we show results of the hull number on complementary prisms GG when G is a tree, when G is a disconnected graph and when G is a cograph. Finally, we also show that in the geodetic convexity, the hull number on the complementary prism GG is unlimited on connected graphs G and G, unlike what happens in the P3-convexity / Nesta dissertação, consideramos o parâmetro número envoltório em duas convexidades em grafos, a convexidade P3 e a convexidade geodética. Na convexidade P3, obtivemos resultados do número envoltório P3 para o produto Cartesiano, produto forte e produto lexicográfico de grafos. Em especial, em relação ao produto Cartesiano, obtivemos um resultado de complexidade, no qual mostramos que, dado um grafo G, resultante de um produto Cartesiano de dois grafos e um inteiro positivo k, é NP-completo decidir se o número envoltório P3 de G é menor ou igual a k. Também consideramos o número envoltório P3 para prismas complementares GG de grafos G e G conexos, em que mostramos um limite superior um pouco mais justo do que o encontrado na literatura. Na convexidade geodética, mostramos resultados do número envoltório para prismas complementares GG quando G é uma árvore, quando G é um grafo desconexo e quando G é um cografo. Por fim, também mostramos que na convexidade geodética o número envoltório do prisma complementar GG pode ser ilimitado para grafos G e G ambos conexos, diferentemente do que ocorre na convexidade P3.