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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.
31

Problém obchodního cestujícího a metoda GENIUS / Travelling salesman problem and method GENIUS

Škopek, Michal January 2009 (has links)
The target of this thesis is to explain the Travelling Salesman Problem and also create a special program, which will be able to make calculations using the heuristics GENIUS. The Travelling Salesman Problem will be described from two different points of view. The first one is the historical description of the idea of the Travelling Salesman Problem and later will be the problem will be described with some of the very wide number of the calculation methods. For the explanation of the methods, in the thesis there has been chosen some of the algorithms which belong to that methods. The heuristics and also the exact algorithms will be explained. The focus of this thesis is on the heuristics called GENIUS and also in the creation of the program which can calculate it. The program works first with the GENI algorithm and after that it works with US post-optimization algorithm. The program will be described from the point of view of the user and the manual will be written as well. The program will be tested on two different examples and will be compared with the exact algorithm.
32

Dynamic Programming: Salesman to Surgeon

Qian, David January 2013 (has links)
Dynamic Programming is an optimization technique used in computer science and mathematics. Introduced in the 1950s, it has been applied to many classic combinatorial optimization problems, such as the Shortest Path Problem, the Knapsack Problem, and the Traveling Salesman Problem, with varying degrees of practical success. In this thesis, we present two applications of dynamic programming to optimization problems. The first application is as a method to compute the Branch-Cut-and-Price (BCP) family of lower bounds for the Traveling Salesman Problem (TSP), and several vehicle routing problems that generalize it. We then prove that the BCP family provides a set of lower bounds that is at least as strong as the Approximate Linear Program (ALP) family of lower bounds for the TSP. The second application is a novel dynamic programming model used to determine the placement of cuts for a particular form of skull surgery called Cranial Vault Remodeling.
33

Solving Traveling Salesman Problem With a non-complete Graph

Emami Taba, Mahsa Sadat January 2009 (has links)
One of the simplest, but still NP-hard, routing problems is the Traveling Salesman Problem (TSP). In the TSP, one is given a set of cities and a way of measuring the distance between cities. One has to find the shortest tour that visits all cities exactly once and returns back to the starting city. In state-of-the-art algorithms, they all assume that a complete graph is given as an input. However, for very large graphs, generating all edges in a complete graph, which corresponds to finding shortest paths for all city pairs, could be time-consuming. This is definitely a major obstacle for some real-life applications, especially when the tour needs to be generated in real-time. The objective, in this thesis, is to find a near-optimal TSP tour with a reduced set of edges in the complete graph. In particular, the following problems are investigated: which subset of edges can be produced in a shorter time comparing to the time for generating the complete graph? Is there a subset of edges in the complete graph that results in a better near-optimal tour than other sets? With a non-complete graph, which improvement algorithms work better? In this thesis, we study six algorithms to generate subsets of edges in a complete graph. To evaluate the proposed algorithms, extensive experiments are conducted with the well-known TSP data in a TSP library. In these experiments, we evaluate these algorithms in terms of tour quality, time and scalability.
34

Solving Traveling Salesman Problem With a non-complete Graph

Emami Taba, Mahsa Sadat January 2009 (has links)
One of the simplest, but still NP-hard, routing problems is the Traveling Salesman Problem (TSP). In the TSP, one is given a set of cities and a way of measuring the distance between cities. One has to find the shortest tour that visits all cities exactly once and returns back to the starting city. In state-of-the-art algorithms, they all assume that a complete graph is given as an input. However, for very large graphs, generating all edges in a complete graph, which corresponds to finding shortest paths for all city pairs, could be time-consuming. This is definitely a major obstacle for some real-life applications, especially when the tour needs to be generated in real-time. The objective, in this thesis, is to find a near-optimal TSP tour with a reduced set of edges in the complete graph. In particular, the following problems are investigated: which subset of edges can be produced in a shorter time comparing to the time for generating the complete graph? Is there a subset of edges in the complete graph that results in a better near-optimal tour than other sets? With a non-complete graph, which improvement algorithms work better? In this thesis, we study six algorithms to generate subsets of edges in a complete graph. To evaluate the proposed algorithms, extensive experiments are conducted with the well-known TSP data in a TSP library. In these experiments, we evaluate these algorithms in terms of tour quality, time and scalability.
35

A science based emission factor for particulate matter emitted from cotton harvesting

Wanjura, John David 15 May 2009 (has links)
Poor regional air quality in some states across the US cotton belt has resulted in increased pressure on agricultural sources of particulate matter (PM) from air pollution regulators. Moreover, inaccurate emission factors used in the calculation of annual emissions inventories led to the identification of cotton harvesting as a significant source of PM10 in California and Arizona. As a result, cotton growers in these states are now required to obtain air quality permits and submit management practice plans detailing the actions taken by the producer to reduce fugitive PM emissions from field operations. The objective of this work was to develop accurate PM emission factors for cotton harvesting in terms of total suspended particulate (TSP), PM10, and PM2.5. Two protocols were developed and used to develop PM emission factors from cotton harvesting operations on three farms in Texas during 2006 and 2007. Protocol one utilized TSP concentrations measured downwind of harvesting operations with meteorological data measured onsite in a dispersion model to back-calculate TSP emission flux values. Flux values, determined with the regulatory dispersion models ISCST3 and AERMOD, were converted to emission factors and corrected with results from particle size distribution (PSD) analyses to report emission factors in terms of PM10 and PM2.5. Emission factors were developed for two-row (John Deere 9910) and sixrow (John Deere 9996) cotton pickers with protocol one. The uncertainty associated with the emission factors developed through protocol one resulted in no significant difference between the emission factors for the two machines. Under the second protocol, emission concentrations were measured onboard the six-row cotton picker as the machine harvested cotton. PM10 and PM2.5 emission factors were developed from TSP emission concentration measurements converted to emission rates using the results of PSD analysis. The total TSP, PM10, and PM2.5 emission factors resulting from the source measurement protocol are 1.64 ± 0.37, 0.55 ± 0.12, and 1.58E- 03 ± 4.5E-04 kg/ha, respectively. These emission factors contain the lowest uncertainty and highest level of precision of any cotton harvesting PM emission factors ever developed. Thus, the emission factors developed through the source sampling protocol are recommended for regulatory use.
36

Greedy randomized adaptive search procedure for traveling salesman problem

Lee, Seung Ho 16 August 2006 (has links)
In this thesis we use greedy randomize adaptive search procedure (GRASP) to solve the traveling salesman problem (TSP). Starting with nearest neighbor method to construct the initial TSP tour, we apply the 2-opt and the path-relinking method for the initial tour improvement. To increase 2-opt search speed, fixed-radius near neighbor search and don0t − look bit techniques are introduced. For the same reason a new efficient data structure, the reverse array, is proposed to represent the TSP tour. Computational results show that GRASP gives fairly good solutions in a short time.
37

Iteratyviosios tabu paieškos algoritmo komivojažieriaus uždaviniui tyrimas / Analysis of iterated tabu search for the traveling salesman problem

Simaitis, Rokas 02 June 2006 (has links)
In this work, the iterated tabu search (ITS) algorithm for the traveling salesman problem (TSP) is discussed. The TSP is a well-known combinatorial optimization problem. Thus, solving the TSP means searching for the shortest closed tour in which every city is visited exactly once. Various heuristic algorithms can be used for solving the TSP, among them, tour construction heuristics, simulated annealing, genetic algorithms, etc. One of the promising heuristic techniques is the iterated tabu search approach. ITS consists of two main parts: standard tabu search (TS) and mutation of solutions. The goal of TS is finding a locally optimal solution in the neighbourhood of the current solution, while the mutation operators are responsible for escaping from the current local optimum and moving towards new regions in the solution space. Several mutation procedures have been analyzed in this work, in particular, exchange mutation, insert mutation, inversion mutation, and others. In order to investigated the performance of the mutation operators, computational experiments with the test instances from the TSP instances library TSPLIB were carried out. The results obtained from these experiments show that the mutation operators play the important role and influence the solution quality significantly.
38

Dynamic Programming: Salesman to Surgeon

Qian, David January 2013 (has links)
Dynamic Programming is an optimization technique used in computer science and mathematics. Introduced in the 1950s, it has been applied to many classic combinatorial optimization problems, such as the Shortest Path Problem, the Knapsack Problem, and the Traveling Salesman Problem, with varying degrees of practical success. In this thesis, we present two applications of dynamic programming to optimization problems. The first application is as a method to compute the Branch-Cut-and-Price (BCP) family of lower bounds for the Traveling Salesman Problem (TSP), and several vehicle routing problems that generalize it. We then prove that the BCP family provides a set of lower bounds that is at least as strong as the Approximate Linear Program (ALP) family of lower bounds for the TSP. The second application is a novel dynamic programming model used to determine the placement of cuts for a particular form of skull surgery called Cranial Vault Remodeling.
39

Papel de quimiocinas e moléculas de adesão na patogênese da infecção pelo HTLV-1

Silva, Mariele Guerra Lemos da January 2016 (has links)
Submitted by Pós Imunologia (ppgimicsufba@gmail.com) on 2017-02-07T18:26:27Z No. of bitstreams: 1 DISSERTACAO DE MESTRADO MARIELE GUERRA(PPGIM).pdf: 2138129 bytes, checksum: 16fc71d570a0b0413b7ccbe7d4b343f7 (MD5) / Approved for entry into archive by Delba Rosa (delba@ufba.br) on 2017-02-08T16:13:35Z (GMT) No. of bitstreams: 1 DISSERTACAO DE MESTRADO MARIELE GUERRA(PPGIM).pdf: 2138129 bytes, checksum: 16fc71d570a0b0413b7ccbe7d4b343f7 (MD5) / Made available in DSpace on 2017-02-08T16:13:35Z (GMT). No. of bitstreams: 1 DISSERTACAO DE MESTRADO MARIELE GUERRA(PPGIM).pdf: 2138129 bytes, checksum: 16fc71d570a0b0413b7ccbe7d4b343f7 (MD5) / Capes / O vírus linfotrópico de células T humana tipo 1 (HTLV-1) é encontrado no mundo todo. A infecção pelo HTLV-1 é caracterizada por uma resposta imune exacerbada, com produção espontânea de IFN- e TNF. Estas citocinas são responsáveis por aumentar a expressão de quimiocinas e moléculas de adesão e facilitar a entrada de linfócitos ativados para o sistema nervoso central (SNC). O objetivo deste estudo foi avaliar o papel de quimiocinas e moléculas de adesão na patogênese da infecção pelo HTLV-1. Quimiocinas pró-inflamatórias (CXCL9 e CXCL10) e moléculas de adesão solúveis (sICAM-1 e sVCAM-1) foram determinadas por ELISA, no soro e líquor de diferentes grupos de indivíduos infectados pelo HTLV-1 (portador assintomático, indivíduos com bexiga hiperativa e HAM/TSP). Frequência e mediana de intensidade de fluorescência (MIF) de linfócitos e de monócitos expressando ligantes das moléculas de adesão (CD11a e CD49d) e receptor de quimiocinas (CXCR3) foram analisadas por citometria de fluxo. CXCL9 e CXCL10 estavam mais elevados tanto no soro quanto no líquor dos pacientes com HAM/TSP (p>0,05). As moléculas de adesão não diferiram entre os grupos, apesar da tendência de maior produção de sVCAM-1 na HAM/TSP. sVCAM-1 correlacionou-se positivamente com quimiocinas no soro dos indivíduos infectados pelo HTLV-1 (p>0,05). De modo geral, a MIF de células CD4+, CD8+ e CD14+ expressando CD11a e CXCR3 foi menor na HAM/TSP. Estes achados confirmam a participação das quimiocinas na migração das células infectadas pelo HTLV-1 para o SNC e sugerem, porém não são suficientes para atestar a participação das moléculas de adesão na patogênese da HAM/TSP.
40

Uso do Nintendo Wii em pacientes com HAM/TSP: Ensaio Clínico Randomizado

Arnaut, Victor Almeida Cardoso de Oliveira 25 February 2014 (has links)
Submitted by Edileide Reis (leyde-landy@hotmail.com) on 2015-04-15T04:30:49Z No. of bitstreams: 1 Victor Almeida Cardoso de Oliveira Arnaut.pdf: 1120575 bytes, checksum: 7d6d91fc543f3fbe7dc1a5293fd94129 (MD5) / Made available in DSpace on 2015-04-15T04:30:49Z (GMT). No. of bitstreams: 1 Victor Almeida Cardoso de Oliveira Arnaut.pdf: 1120575 bytes, checksum: 7d6d91fc543f3fbe7dc1a5293fd94129 (MD5) Previous issue date: 2014-02-25 / A mielopatia associada ao HTLV-1 ou paraparesia espástica tropical (HAM/TSP) é uma doença desmielinizante crônica e progressiva e que afeta predominantemente a medula espinal. O equilíbrio e a locomoção nos indivíduos acometidos ficam comprometidos e exige alternativas terapêuticas para a reabilitação. Objetivo: Verificar o efeito da Wii Terapia como recurso terapêutico adicional no tratamento de pacientes com HAM/TSP, verificando impactos no equilíbrio, dor e qualidade de vida. Metodologia: Ensaio clínico randomizado duplo cego realizado com 9 indivíduos com diagnóstico confirmado pelos critérios da OMS, divididos em dois grupos – G1 que realizou exercícios terapêuticos associado ao uso de jogos do Nintendo Wii e G2 que realizou somente exercícios terapêuticos. Todos os participantes foram submetidos a uma avaliação da dor pela escala visual analógica (EVA) e do equilíbrio pela escala de Berg, responderam a um questionário sobre qualidade de vida (SF-36), antes e depois das 10 sessões. Os dados foram analisados através dos testes T pareado (intra grupo) e não pareado (inter grupo), com alfa de 5% , poder de 80% e IC 95%. Resultados: Na análise intra grupo foi encontrada diferença apenas no escore da Escala de Berg e dos domínios capacidade funcional e aspectos emocionais do grupo teste (p<0,05). Na comparação do delta dos escores entre os grupos, os domínios aspectos emocionais (p=0,027) e capacidade funcional (p=0,054) foram diferentes entre os grupos. Conclusão: A terapia com realidade virtual usando o Nintendo Wii demonstrou impacto positivo superior em relação ao protocolo de exercícios funcionais sobre o equilíbrio e sobre os domínios de capacidade funcional e aspectos emocionais na qualidade de vida dos participantes.

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