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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.
21

Efficient routing of snow removal vehicles

Omer, Masoud. January 2007 (has links)
Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains viii, 95 p. : ill. Includes abstract. Includes bibliographical references (p. 79-91).
22

Solução do problema de corte bidimensional de peças retângulares tipo não-guilhotinado usando simulated annealing /

Lopez Sepulveda, Gloria Patricia. January 2013 (has links)
Orientador: Romero Lázaro, Rubén Augusto / Banca: Marcos Julio Rider Flores / Banca: Eduardo Nobuhiro Asada / Resumo: Os problemas de corte ótimo são considerados como clássicos dentro da pesquisa operacional, dado sua grande área de aplicação na industria e sua alta complexidade matemática e computacional. Um dos problemas mais conhecidos desta classe é o chamado Cutting Stock Problem, o qual permite dividir uma placa em varias peças de diversos tamanhos, com a finalidade de obter a configuração que maximize a área da placa que está sendo utilizada. Dado o nível de dificuldade e a grande quantidade de aplicações deste problemas em diversas áreas, existe muito interesse em criar novos procedimentos eficientes para resolver este tipo de problemas. Nesta dissertação, é apresentado o estado da arte dos diversos problemas de corte bidimensional de peças retangulares em uma única placa, em varias placas e em rolos, considerando a possibilidade de rotacionar as peças em um ângulo de 90 e com restrições de corte tipo não-guilhotinado. Além disso, são descritas as abordagens matemáticas aplicadas pelos diversos pesquisadores dedicados a resolver estes problemas. Este trabalho está focado em resolver exclusivamente o Cutting Stock Problem com e sem rotação de peças. Portanto, é proposto um tipo de codificação binária com vista a ser aplicada neste tipo de problema e resolvê-lo mediante o uso do algoritmo heurístico Bottom-Left, em conjunto com a metaheurística Simulated Annealing. Finalmente, para comprovar a eficiência da metodologia apresentada, foram utilizados alguns casos de estudo da literatura especializada, com diferentes níveis de complexidade. Para cada caso, são apresentados os resultados obtidos e é realizada uma comparação dos métodos de solução propostos para resolver o Cutting Stock Problem com e sem rotação de peças. / Abstract: The problems of optimal cutting are considered as classic within the operational research, given their large area of application in industry and their high computational and mathematic complexity. One of the most well-known of this kind of problem is called the Cutting Stock Problem, which allows to divide a plate in several pieces of various sizes, in order to obtain the configuration that maximizes the area of the plate being used. Given the level of difficulty and the large number of applications of this problem in several areas, there is interest in creating new efficient procedures for solving this kind of problem. In this dissertation, it is presented the state of the art of the two-dimensional cutting problems of rectangular pieces on a single plate, in several plates and rollers, considering the possibility of rotating the pieces at an angle of 90 in which the cuts are restricted to non-guillotined type. Furthermore, the mathematical approaches applied by different researchers dedicated to solving these problems are described. This work is focused exclusively on solving the Cutting Stock Problem with and without rotating pieces. Therefore, a kind of binary encoding in order to be applied to this kind of problem and to solving it through the use of the Bottom-Left heuristic algorithm in conjunction with Simulated Annealing are proposed. Finally, to prove the efficiency of the presented methodology, some study cases from the specialized literature were used, with different levels of complexity. For each case, the results are presented and a comparison of the proposed solution methods for solving the Cutting Stock Problem with and without rotating pieces is performed. / Mestre
23

Solução do problema de corte bidimensional de peças retângulares tipo não-guilhotinado usando simulated annealing

Lopez Sepulveda, Gloria Patricia [UNESP] 25 March 2013 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:22:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-03-25Bitstream added on 2014-06-13T18:49:35Z : No. of bitstreams: 1 000740375.pdf: 2082789 bytes, checksum: d1483f48718c198c624d0f146dae6d70 (MD5) / Os problemas de corte ótimo são considerados como clássicos dentro da pesquisa operacional, dado sua grande área de aplicação na industria e sua alta complexidade matemática e computacional. Um dos problemas mais conhecidos desta classe é o chamado Cutting Stock Problem, o qual permite dividir uma placa em varias peças de diversos tamanhos, com a finalidade de obter a configuração que maximize a área da placa que está sendo utilizada. Dado o nível de dificuldade e a grande quantidade de aplicações deste problemas em diversas áreas, existe muito interesse em criar novos procedimentos eficientes para resolver este tipo de problemas. Nesta dissertação, é apresentado o estado da arte dos diversos problemas de corte bidimensional de peças retangulares em uma única placa, em varias placas e em rolos, considerando a possibilidade de rotacionar as peças em um ângulo de 90 e com restrições de corte tipo não-guilhotinado. Além disso, são descritas as abordagens matemáticas aplicadas pelos diversos pesquisadores dedicados a resolver estes problemas. Este trabalho está focado em resolver exclusivamente o Cutting Stock Problem com e sem rotação de peças. Portanto, é proposto um tipo de codificação binária com vista a ser aplicada neste tipo de problema e resolvê-lo mediante o uso do algoritmo heurístico Bottom-Left, em conjunto com a metaheurística Simulated Annealing. Finalmente, para comprovar a eficiência da metodologia apresentada, foram utilizados alguns casos de estudo da literatura especializada, com diferentes níveis de complexidade. Para cada caso, são apresentados os resultados obtidos e é realizada uma comparação dos métodos de solução propostos para resolver o Cutting Stock Problem com e sem rotação de peças. / The problems of optimal cutting are considered as classic within the operational research, given their large area of application in industry and their high computational and mathematic complexity. One of the most well-known of this kind of problem is called the Cutting Stock Problem, which allows to divide a plate in several pieces of various sizes, in order to obtain the configuration that maximizes the area of the plate being used. Given the level of difficulty and the large number of applications of this problem in several areas, there is interest in creating new efficient procedures for solving this kind of problem. In this dissertation, it is presented the state of the art of the two-dimensional cutting problems of rectangular pieces on a single plate, in several plates and rollers, considering the possibility of rotating the pieces at an angle of 90 in which the cuts are restricted to non-guillotined type. Furthermore, the mathematical approaches applied by different researchers dedicated to solving these problems are described. This work is focused exclusively on solving the Cutting Stock Problem with and without rotating pieces. Therefore, a kind of binary encoding in order to be applied to this kind of problem and to solving it through the use of the Bottom-Left heuristic algorithm in conjunction with Simulated Annealing are proposed. Finally, to prove the efficiency of the presented methodology, some study cases from the specialized literature were used, with different levels of complexity. For each case, the results are presented and a comparison of the proposed solution methods for solving the Cutting Stock Problem with and without rotating pieces is performed.
24

APPLYING BLIND SOURCE SEPARATION TO MAGNETIC ANOMALY DETECTION

Unknown Date (has links)
The research shows a novel approach for the Magnetic Anomaly Differentiation and Localization Algorithm, which simultaneously localizes multiple magnetic anomalies with weak total field signatures (tens of nT). In particular, it focuses on the case where there are two homogeneous targets with known magnetic moments. This was done by analyzing the magnetic signals and adapting Independent Component Analysis (ICA) and Simulated Annealing (SA) to solve the problem statement. The results show the groundwork for using a combination of fastICA and SA to give localization errors of 3 meters or less per target in simulation and achieved a 58% success rate. Experimental results experienced additional errors due to the effects of magnetic background, unknown magnetic moments, and navigation error. While one target was localized within 3 meters, only the latest experimental run showed the second target approaching the localization specification. This highlighted the need for higher signal-to-noise ratio and equipment with better navigational accuracy. The data analysis was used to provide recommendations on the needed equipment to minimize observed errors and improve algorithm success. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection
25

A new hybrid meta-heuristic algorithm for solving single machine scheduling problems

Zlobinsky, Natasha January 2017 (has links)
A dissertation submitted in partial ful lment of the degree of Master of Science in Engineering (Electrical) (50/50) in the Faculty of Engineering and the Built Environment Department of Electrical and Information Engineering May 2017 / Numerous applications in a wide variety of elds has resulted in a rich history of research into optimisation for scheduling. Although it is a fundamental form of the problem, the single machine scheduling problem with two or more objectives is known to be NP-hard. For this reason we consider the single machine problem a good test bed for solution algorithms. While there is a plethora of research into various aspects of scheduling problems, little has been done in evaluating the performance of the Simulated Annealing algorithm for the fundamental problem, or using it in combination with other techniques. Speci cally, this has not been done for minimising total weighted earliness and tardiness, which is the optimisation objective of this work. If we consider a mere ten jobs for scheduling, this results in over 3.6 million possible solution schedules. It is thus of de nite practical necessity to reduce the search space in order to nd an optimal or acceptable suboptimal solution in a shorter time, especially when scaling up the problem size. This is of particular importance in the application area of packet scheduling in wireless communications networks where the tolerance for computational delays is very low. The main contribution of this work is to investigate the hypothesis that inserting a step of pre-sampling by Markov Chain Monte Carlo methods before running the Simulated Annealing algorithm on the pruned search space can result in overall reduced running times. The search space is divided into a number of sections and Metropolis-Hastings Markov Chain Monte Carlo is performed over the sections in order to reduce the search space for Simulated Annealing by a factor of 20 to 100. Trade-o s are found between the run time and number of sections of the pre-sampling algorithm, and the run time of Simulated Annealing for minimising the percentage deviation of the nal result from the optimal solution cost. Algorithm performance is determined both by computational complexity and the quality of the solution (i.e. the percentage deviation from the optimal). We nd that the running time can be reduced by a factor of 4.5 to ensure a 2% deviation from the optimal, as compared to the basic Simulated Annealing algorithm on the full search space. More importantly, we are able to reduce the complexity of nding the optimal from O(n:n!) for a complete search to O(nNS) for Simulated Annealing to O(n(NMr +NS)+m) for the input variables n jobs, NS SA iterations, NM Metropolis- Hastings iterations, r inner samples and m sections. / MT 2017
26

Optimal geometric design of VLSI interconnect networks by simulated annealing.

January 1995 (has links)
by Sau-yuen Wong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 77-82). / Acknowledgement --- p.i / Abstract --- p.ii / List of Tables --- p.ii / List of Figures --- p.iv / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Review of Previous Work --- p.4 / Chapter 2.1 --- Optimization of Delay and Layout Design --- p.4 / Chapter 2.2 --- Simulated Annealing --- p.8 / Chapter 3 --- Definition of Circuit Model --- p.12 / Chapter 4 --- Evaluation of Delay --- p.16 / Chapter 4.1 --- RC-tree and Elmore Delay --- p.16 / Chapter 4.2 --- Exponential Decayed Polynomial Function --- p.17 / Chapter 4.3 --- Two-pole Approximation --- p.18 / Chapter 4.4 --- AWE and Adopted Delay Model --- p.19 / Chapter 5 --- Delay Minimization by Simulated Annealing --- p.28 / Chapter 5.1 --- Cost Function --- p.28 / Chapter 5.2 --- Neighbor Moves --- p.30 / Chapter 5.2.1 --- Logical models --- p.31 / Chapter 5.2.2 --- Discretization of Solution Space --- p.32 / Chapter 5.2.3 --- Valid Configurations --- p.35 / Chapter 5.2.4 --- Valid Moves --- p.39 / Chapter 5.2.5 --- Modification to the Newly Generated Graph --- p.41 / Chapter 5.2.6 --- Access to Neighbor configuration --- p.43 / Chapter 5.2.7 --- Reduction of Solution Space --- p.45 / Chapter 5.2.8 --- Correctness of the Algorithm --- p.48 / Chapter 5.2.9 --- Completeness of the Algorithm --- p.49 / Chapter 6 --- Experimental result --- p.56 / Chapter 6.1 --- Optimization of Overall Performance --- p.58 / Chapter 6.2 --- Optimization on Individual Delay --- p.70 / Chapter 7 --- Conclusion --- p.74 / A --- p.76 / Bibliography
27

Computation of physical properties of materials using percolation networks.

January 1999 (has links)
Wong Yuk Chun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 71-74). / Abstracts in English and Chinese. / Abstract --- p.ii / Acknowledgments --- p.iii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Motivation --- p.2 / Chapter 1.2 --- The Scope of the Project --- p.2 / Chapter 1.3 --- An Outline of the Thesis --- p.3 / Chapter 2 --- Related Work --- p.5 / Chapter 2.1 --- Percolation Effect --- p.5 / Chapter 2.2 --- Percolation Models --- p.6 / Chapter 2.2.1 --- Site Percolation --- p.6 / Chapter 2.2.2 --- Bond Percolation --- p.8 / Chapter 2.3 --- Simulated Annealing --- p.8 / Chapter 3 --- Electrical Property --- p.11 / Chapter 3.1 --- Electrical Conductivity --- p.11 / Chapter 3.2 --- Physical Model --- p.13 / Chapter 3.3 --- Algorithm --- p.16 / Chapter 3.3.1 --- Simulated Annealing --- p.18 / Chapter 3.3.2 --- Neighborhood Relation and Objective Function --- p.19 / Chapter 3.3.3 --- Configuration Space --- p.21 / Chapter 3.3.4 --- Annealing Schedule --- p.22 / Chapter 3.3.5 --- Expected Time Bound --- p.23 / Chapter 3.4 --- Results --- p.26 / Chapter 3.5 --- Discussion --- p.27 / Chapter 4 --- Thermal Properties --- p.30 / Chapter 4.1 --- Thermal Expansivity --- p.31 / Chapter 4.2 --- Physical Model --- p.32 / Chapter 4.2.1 --- The Physical Properties --- p.32 / Chapter 4.2.2 --- Objective Function and Neighborhood Relation --- p.37 / Chapter 4.3 --- Algorithm --- p.38 / Chapter 4.3.1 --- Parallel Simulated Annealing --- p.39 / Chapter 4.3.2 --- The Physical Annealing Schedule --- p.42 / Chapter 4.4 --- Results --- p.43 / Chapter 4.5 --- Discussion --- p.47 / Chapter 5 --- Scaling Properties --- p.48 / Chapter 5.1 --- Problem Define --- p.49 / Chapter 5.2 --- Physical Model --- p.50 / Chapter 5.2.1 --- The Physical Properties --- p.50 / Chapter 5.2.2 --- Bond Stretching Force --- p.50 / Chapter 5.2.3 --- Objective Function and Configuration Space --- p.51 / Chapter 5.3 --- Algorithm --- p.52 / Chapter 5.3.1 --- Simulated Annealing --- p.52 / Chapter 5.3.2 --- The Conjectural Method --- p.54 / Chapter 5.3.3 --- The Physical Annealing Schedule --- p.56 / Chapter 5.4 --- Results --- p.57 / Chapter 5.4.1 --- Case I --- p.59 / Chapter 5.4.2 --- Case II --- p.60 / Chapter 5.4.3 --- Case III --- p.60 / Chapter 5.5 --- Discussion --- p.61 / Chapter 6 --- Conclusion --- p.62 / Chapter A --- An Example on Studying Electrical Resistivity --- p.64 / Chapter B --- Theory of Elasticity --- p.67 / Chapter C --- Random Number Generator --- p.69 / Bibliography
28

Contributions to the theory and practice of hypothesis testing

Sriananthakumar, Sivagowry, 1968- January 2000 (has links)
Abstract not available
29

Simulated annealing algorithms for the optimization of particulate composite structures analyzed by X-FEM

Renova, Elvia Paola. January 2008 (has links)
Thesis (M.S.)--University of Texas at El Paso, 2008. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.
30

Caching in iterative hill climbing /

Karhi, David, January 1900 (has links)
Thesis (M.S.)--Texas State University--San Marcos, 2008. / Vita. Includes bibliographical references (leaves 50-51). Also available on microfilm.

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