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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Problema das sequ?ncias justas ponderadas

Pess?a, Bruno Jefferson de Sousa 15 December 2017 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-02-21T21:29:05Z No. of bitstreams: 1 BrunoJeffersonDeSousaPessoa_TESE.pdf: 1029802 bytes, checksum: fb7e1bbf01b30106e4b0a64511f955d1 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-02-22T22:38:00Z (GMT) No. of bitstreams: 1 BrunoJeffersonDeSousaPessoa_TESE.pdf: 1029802 bytes, checksum: fb7e1bbf01b30106e4b0a64511f955d1 (MD5) / Made available in DSpace on 2018-02-22T22:38:00Z (GMT). No. of bitstreams: 1 BrunoJeffersonDeSousaPessoa_TESE.pdf: 1029802 bytes, checksum: fb7e1bbf01b30106e4b0a64511f955d1 (MD5) Previous issue date: 2017-12-15 / Problemas de escalonamento aos quais s?o impostas restri??es relativas ?s dist?ncias temporais entre sucessivas execu??es de uma mesma tarefa possuem um grande n?mero de aplica??es, que variam desde o escalonamento de tarefas em sistemas de tempo real ? produ??o de autom?veis em uma linha de montagem. O presente trabalho apresenta um novo problema de otimiza??o, denominado de Problema das Sequ?ncias Justas Ponderadas (PSJP), que faz parte dessa classe de problemas. Al?m do estudo da complexidade computacional do PSJP, ? apresentada uma formula??o matem?tica baseada em programa??o linear inteira mista e uma s?rie de cortes que aprimoram sua resolu??o via m?todos exatos. Para resolv?-lo, foram elaborados um m?todo iterativo que reduz o n?mero de vari?veis da formula??o proposta e uma solu??o heur?stica desenvolvida a partir da combina??o de meta-heur?sticas cl?ssicas da literatura. Experimentos computacionais mostram que, para um dado limite de tempo, as abordagens propostas aumentam significativamente o n?mero de inst?ncias resolvidas, preservando-se a qualidade das solu??es. / Scheduling problems on which constraints are imposed with regard to the temporal distances between successive executions of the same task have numerous applications, ranging from task scheduling in real-time systems to automobile production on a mixedmodel assembly line. This paper introduces a new NP-hard optimization problem belonging to this class of problems, namely the Weighted Fair Sequences Problem (WFSP). In addition to the study of the computational complexity of the WFSP, we present a mathematical formulation based on mixed-integer linear programming as well as a serie of cuts that improve the problem resolution via exact methods. To solve the WFSP, we propose an iterative method that greatly reduces the number of variables in the WFSP formulation and a heuristic solution developed from the combination of classical metaheuristics from the literature. Computational experiments show that, for a given time limit, the proposed approaches significantly increase the number of instances solved, preserving the quality of the solutions.
2

Algoritmos meta-heur?sticos para a solu??o do problema do caixeiro viajante com m?ltiplas caronas / Metaheuristic algorithms for the solution of the traveling salesman with multiple ridesharing

Ara?jo, Guilherme Fernandes de 12 February 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-08-16T20:15:31Z No. of bitstreams: 1 GuilhermeFernandesDeAraujo_DISSERT.pdf: 1848505 bytes, checksum: eaa10d2add37ab0c93d005b148c492ee (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-08-17T22:17:58Z (GMT) No. of bitstreams: 1 GuilhermeFernandesDeAraujo_DISSERT.pdf: 1848505 bytes, checksum: eaa10d2add37ab0c93d005b148c492ee (MD5) / Made available in DSpace on 2016-08-17T22:17:58Z (GMT). No. of bitstreams: 1 GuilhermeFernandesDeAraujo_DISSERT.pdf: 1848505 bytes, checksum: eaa10d2add37ab0c93d005b148c492ee (MD5) Previous issue date: 2016-02-12 / O Problema do Caixeiro Viajante com Caronas M?ltiplas (PCV-MCa) ? uma classe do Caixeiro Viajante Capacitado que apresenta a possibilidade de compartilhamento de assentos para passageiros aproveitando os deslocamentos do caixeiro entre as localidades do ciclo. O caixeiro divide o custo do trajeto com os passageiros embarcados. O modelo pode representar uma situa??o real em que, por exemplo, motoristas est?o dispostos a compartilhas trechos de sua viagem com turistas que pretendem se deslocar entre duas localidades visitadas pela rota do motorista, aceitando compartilhar o ve?culo com outros indiv?duos e visitando outras localidades do ciclo. / The Traveling Salesman with Multiple Ridesharing (TSP-MR) is a type of the Capacitated Traveling Salesman, which presents the possibility of sharing seats with passengers taking advantage of the paths the salesman travels through his cycle. The salesman shares the cost of a path with the boarded passengers. This model can portray a real situation in which, for example, drivers are willing to share parts of a trip with tourists that wish to move between two locations visited by the driver?s route, accepting to share the vehicle with other individuals visiting other locations within the cycle. This work proposes a mathematical formulation for the problem, and an exact and metaheuristics algorithms for its solution, comparing them.
3

Algoritmos de solu??o para o problema do caixeiro viajante com passageiros e quota / Solution algorithms for the traveling salesman problem with rideshare and quota

Silva, Jean Gleison de Santana 31 July 2017 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-11-01T21:17:50Z No. of bitstreams: 1 JeanGleisonDeSantanaSilva_DISSERT.pdf: 1141115 bytes, checksum: 891de7a8a9407e8af54f241f1a174785 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-11-07T22:09:47Z (GMT) No. of bitstreams: 1 JeanGleisonDeSantanaSilva_DISSERT.pdf: 1141115 bytes, checksum: 891de7a8a9407e8af54f241f1a174785 (MD5) / Made available in DSpace on 2017-11-07T22:09:47Z (GMT). No. of bitstreams: 1 JeanGleisonDeSantanaSilva_DISSERT.pdf: 1141115 bytes, checksum: 891de7a8a9407e8af54f241f1a174785 (MD5) Previous issue date: 2017-07-31 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / O Problema do Caixeiro Viajante com Passageiros e Quota pertence ? classe de Problemas do Caixeiro Viajante com Quota. Neste problema, considera-se uma vantagem econ?mica quando o caixeiro, viajando em um ve?culo privado, embarca passageiros que passam a dividir as despesas da viagem com ele. O modelo pode representar situa??es reais onde o motorista tem uma rota de visita de cidade predefinida, na qual a cada cidade est? associado um b?nus, sendo demandada a coleta de um valor m?nimo desses b?nus, na fun??o objetivo da variante investigada leva-se em conta a possibilidade da redu??o dos custos do caixeiro embarcando pessoas em seu ve?culo. Um modelo matem?tico, seis algoritmos evolucion?rios, um GRASP e um heur?stico s?o apresentados para o problema. O comportamento dos algoritmos propostos ? analisado em um experimento computacional com 48 inst?ncias. / The Traveling Salesman Problem with Ridesharing and Quota belongs to the class of Quota Traveling Salesman problems. In this problem, it is considered the economic advantage achieved when the salesman, traveling in a private vehicle, gives ride to passengers who share travel expenses with him. The model can represent real situations where a driver programs a route to visit cities, each of which associated with a bonus, with the requirement of collecting a minimum sum of bonuses and taking into account the possibility of reducing costs due to people embarked in his vehicle. A math model, six evolutionary algorithms, a GRASP and one heuristic are presented for the problem addressed. The behavior of the proposed algorithms is analyzed on a computational experiment with 48 instances.

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