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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.
11

Concurrent design of facility layout and flow-based department formation

Chae, Junjae 17 February 2005 (has links)
The design of facility layout takes into account a number of issues including the formation of departments, the layout of these, the determination of the material handling methods to be used, etc. To achieve an efficient layout, these issues should be examined simultaneously. However, in practice, these problems are generally formulated and solved sequentially due to the complicated nature of the integrated problem. Specifically, there is close interaction between the formation of departments and layout of these departments. These problems are treated as separate problems that are solved sequentially. This procedure is mainly due to the complexity of each problem and the interrelationships between them. In this research, we take a first step toward integrating the flow-based department formation and departmental layout into comprehensive mathematical models and develop appropriate solution procedures. It is expected that these mathematical models and the solution procedures developed will generate more efficient manufacturing system designs, insights into the nature of the concurrent facility layout problem, and new research directions.
12

Cutting-Plane Separation Strategies for Semidefinite Programming Models to Solve Single-Row Facility Layout Problems

Yen, Ginger January 2008 (has links)
The single-row facility layout problem (SRFLP) is concerned with finding the optimal linear placement of n departments with different lengths in a straight line. It is typically achieved by minimizing the cost associated with the interactions between the departments. The semidefinite programming (SDP) relaxation model that incorporates cutting planes proposed recently by Anjos, Kennings, and Vannelli (AKV) was considered a breakthrough in the field. This thesis presents a new SDP model AKV' and compares the two relaxations. The AKV' is largely based on the previous model, but it reduces the number of linear constraints from O(n³) to O(n²). Therefore, it reduces the computing time at the expense of a slightly weaker lower bound. However, AKV' is observed to pay off as the instance size increases. By examining the gap for both the AKV and AKV' relaxations, we notice that both relaxations generate very small gaps at the root node, which demonstrates the effectiveness of the relaxations. Six different strategies are presented to separate the cutting planes for the medium-sized SRFLP. In combination with the two SDP relaxations, we compare the six strategies using three instances of different characteristics. An overall best strategy is deduced from the computational results, but the best choice of relaxations and the best number of cuts added at each iteration changes depending on the characteristics of the instances. Two new cutting plane strategies are proposed for large instances. This allows the solution to optimality of new instances with 36 departments, which is higher than previously published results in literature. We also briefly point out how the computing time can vary greatly between different sets of data of the same size due to the characteristics of the department lengths.
13

Cutting-Plane Separation Strategies for Semidefinite Programming Models to Solve Single-Row Facility Layout Problems

Yen, Ginger January 2008 (has links)
The single-row facility layout problem (SRFLP) is concerned with finding the optimal linear placement of n departments with different lengths in a straight line. It is typically achieved by minimizing the cost associated with the interactions between the departments. The semidefinite programming (SDP) relaxation model that incorporates cutting planes proposed recently by Anjos, Kennings, and Vannelli (AKV) was considered a breakthrough in the field. This thesis presents a new SDP model AKV' and compares the two relaxations. The AKV' is largely based on the previous model, but it reduces the number of linear constraints from O(n³) to O(n²). Therefore, it reduces the computing time at the expense of a slightly weaker lower bound. However, AKV' is observed to pay off as the instance size increases. By examining the gap for both the AKV and AKV' relaxations, we notice that both relaxations generate very small gaps at the root node, which demonstrates the effectiveness of the relaxations. Six different strategies are presented to separate the cutting planes for the medium-sized SRFLP. In combination with the two SDP relaxations, we compare the six strategies using three instances of different characteristics. An overall best strategy is deduced from the computational results, but the best choice of relaxations and the best number of cuts added at each iteration changes depending on the characteristics of the instances. Two new cutting plane strategies are proposed for large instances. This allows the solution to optimality of new instances with 36 departments, which is higher than previously published results in literature. We also briefly point out how the computing time can vary greatly between different sets of data of the same size due to the characteristics of the department lengths.
14

Concurrent design of facility layout and flow-based department formation

Chae, Junjae 17 February 2005 (has links)
The design of facility layout takes into account a number of issues including the formation of departments, the layout of these, the determination of the material handling methods to be used, etc. To achieve an efficient layout, these issues should be examined simultaneously. However, in practice, these problems are generally formulated and solved sequentially due to the complicated nature of the integrated problem. Specifically, there is close interaction between the formation of departments and layout of these departments. These problems are treated as separate problems that are solved sequentially. This procedure is mainly due to the complexity of each problem and the interrelationships between them. In this research, we take a first step toward integrating the flow-based department formation and departmental layout into comprehensive mathematical models and develop appropriate solution procedures. It is expected that these mathematical models and the solution procedures developed will generate more efficient manufacturing system designs, insights into the nature of the concurrent facility layout problem, and new research directions.
15

Algoritmos híbridos para la resolución del F.L.P. (Facility Layout Problem) basados en colonias de hormigas

Jaén Gómez, Pedro Ildefonso 07 January 2016 (has links)
[EN] The Facilities Layout Problem in a industrial plant (FLP) pursues the good ordenation of the integrating elements (that in this work they will call themselves facilities, understan-ding those elements of the production system that they require space) of a production system and it contemplates, among other, geometric and economic aspects. The eco-nomic aspect has to do with the installation of the plant and with its operation while the geometric one is related with the architecture of the system. Under consideration of these aspects they are derived different formulations of the problem according to the geometric model adopted for represent the solution and according to the function to optimize that can include quantitative terms as installation costs and operation cost (manu-tención) and qualitative terms derived of the chart establishing relationship of activities from the met-hodology SLP. Certain tradition exists in the Educational Unit of Buildings and Architectu-re Industrial (at the moment U.D of Industrial Buldings), on the resolution of this FLP from diverse focuses, what there is origin that already from the years 90, myself, author of this thesis, as well as other partners, let us have implemented some computer applications of several types for the resolution of the same, based, by way of example, in genetic algo-rithms or in fuzzy logic. The last one goal was this one implemented with ACO ("Ant Co-lony Optimization") that this work shows. Anyway, this applications, often used in other works or even with educational ends, they have provided satisfactory results so much in the investigating scheduling as in the academic. At the beginning of the 2000, when the normative of Industrial Buldings Fire Proofing appears, when being starting from then of a preceptive normative in the greater part of industries of new installation, and the position that was continued in the real works was: in a first phase the elaboration of the layout, while in a second phase the application of the preceptive normative of fire proofing was demanded against fires to the layout obtained previously, with obligatory character so much in the industrial field, like in the subsidiary uses that aren't industrials, different from the main one. Any layout that it doesn't complete the fire proofing normative approaches in all the areas, be these industrial or not, it lacks legal validity and therefore it's not viable. In a third phase it is endowed of the thermal appropriate atmosphere, higroscopic, acous-tic and lighting to the obtained solution. In front of this reality, more and more commenda-ble starting from the appearance of the Technical Code of Buildings, that impels the per-formance designing and not in prescriptions, of the non convenience of unlying the design phases, we have started including the approach of the compartmentalization in the design like another objective in the quality of the final adopted solution, and therefore optimizable like any another. Hence in this work we have been carried out a proposal of compart-mentalization algorithm that works starting from the information and approaches that the normative of fires use, and we have also defined a proposal of objective function, as well as a series of parameters that allows to consider like it influences this compartmentaliza-tion in the flow of materials through the different facilities. / [ES] El problema de la distribución en planta de procesos industriales (FLP) persigue la ordenación óptima de los elementos (que en este trabajo se llamarán actividades, conceptuándose como aquellos elementos del sistema de producción que requieren espacio) de un sistema de producción y contempla, entre otros, aspectos geométricos y económicos. El aspecto económico tiene que ver con la instalación de la planta y con su operación mientras que el geométrico se relaciona con la arquitectura del sistema. De la consideración de estos aspectos se derivan diferentes formulaciones del problema según el modelo geométrico adoptado para representar la solución y según la función a optimizar, que puede incluir términos cuantitativos como costes de instalación y de operación (manutención) y términos cualitativos derivados de la tabla relacional de actividades establecida desde la metodología SLP. Existe cierta tradición en la Unidad Docente de Construcción y Arquitectura Industrial (actualmente U.D de Construcciones Industriales), sobre la resolución de este problema de distribución en planta desde diversos enfoques, lo que ha originado que ya desde los años 90, yo mismo, autor de esta Tesis Doctoral, así como otros compañeros, hayamos implementado algunas aplicaciones informáticas de varios tipos para la resolución del mismo, basadas, a modo de ejemplo, en algoritmos genéticos o en lógica borrosa. El último caso el de la aplicación informática que utiliza ACO ("Ant Colony Optimization") que se presenta en este trabajo. En cualquier caso, dichas aplicaciones, a menudo utilizadas en otras investigaciones o incluso con fines docentes, han proporcionado resultados satisfactorios tanto en el plano investigador como en el académico. A principios de los 2000, cuando aparece la normativa de Protección Contra Incendios en Establecimientos Industriales, al tratarse a partir de entonces de una normativa de obligado cumplimiento en la gran mayoría de actividades de nueva planta, y el planteamiento que se siguió al realizar los trabajos y proyectos sobre casos reales fue en una primera fase la elaboración de la distribución en planta, mientras que en una segunda fase se exigía la aplicación de la normativa de protección contra incendios a la distribución en planta obtenida con anterioridad, con carácter obligatorio tanto en el ámbito industrial, como en los usos subsidiaros no industriales diferentes del principal. Cualquier distribución en planta que no cumpla los criterios normativos en todas las zonas, sean éstas industriales o no, carece de validez legal y por tanto no es viable. En una tercera fase se dota del adecuado ambiente térmico, higroscópico, acústico y lumínico a la solución obtenida. Frente a esta realidad, cada vez más plausible a partir de la entrada en vigor del Código Técnico de la edificación, que impulsa el diseño basado en prestaciones y no en prescripciones, de la no conveniencia de desligar las fases de diseño, se ha comenzado por incluir el criterio de la sectorización en el diseño como un objetivo más mesurable en la calidad de la solución final adoptada, y por lo tanto optimizable como cualquier otro. Por ello en este trabajo se ha realizado una propuesta de algoritmo de sectorización, que funciona a partir de la información y criterios que las normativas de incendios utilizan, y se ha definido también una propuesta de función objetivo, así como una serie de parámetros que permiten considerar cómo influye esta sectorización en el trasiego de materiales (fundamentalmente flujos) a través de las distintas actividades. / [CAT] El problema de la distribució en planta de processos industrials (FLP) perseguix l'ordena-ció òptima dels elements (que en este treball es cridaran activitats, conceptuant-se com aquells elements del sistema de producció que requerixen espai) d'un sistema de pro-ducció i contempla, entre altres, aspectes geomètrics i econòmics. L'aspecte econòmic té a veure amb la instal·lació de la planta i amb la seua operació mentres que el geo-mètric es relaciona amb l'arquitectura del sistema. De la consideració d'estos aspectes es deriven diferents formulacions del problema segons el model geomètric adoptat per a representar la solució i segons la funció a optimitzar, que pot incloure termes quantitatius com a costos d'instal·lació i d'operació (manutenció) i termes qualitatius derivats de la taula relacional d'activitats establida des de la metodologia SLP. Hi ha una certa tradició en la Unitat Docent de Construcció i Arquitectura Industrial (actualment U.D de Cons-truccions Industrials) , sobre la resolució d'este problema de distribució en planta des de diversos enfocaments, la qual cosa ha originat que ja des dels anys 90, jo mateix, autor d'esta tesi, així com altres companys, hàgem implementat algunes aplicacions informàti-ques de diversos tipus per a la resolució del mateix, basades, a manera d'exemple, en algoritmes genètics o en lògica borrosa. L'últim cas el de l'aplicació informàtica que uti-litza ACO ("Ant Colony Optimization") que es presenta en este treball. En tot cas, les dites aplicacions, sovint utilitzades en altres investigacions o inclús amb fins docents, han pro-porcionat resultats satisfactoris tant en el pla investigador com en l'acadèmic. A principis dels 2000, quan apareix la normativa de Protecció Contra Incendis en Establiments In-dustrials, al tractar-se a partir de llavors d'una normativa de compliment obligatori en la gran majoria d'activitats de nova planta, i el plantejament que es va seguir en els treballs i projectes reials va ser en una primera fase l'elaboració de la distribució en planta, men-tres que en una segona fase s'exigia l'aplicació de la normativa de protecció contra in-cendis a la distribució en planta obtinguda amb anterioritat, amb caràcter obligatori tant en l'àmbit industrial, com en els usos subsidiar-vos no industrials diferents del principal. Qualsevol distribució en planta que no complisca els criteris normatius en totes les zones, siguen ést. En una tercera fase es dota de l'adequat ambient tèrmic, higroscòpic, acústic i lumínic a la solució obtinguda. Enfront d'esta realitat, cada vegada més plausible a partir de l'entrada en vigor del Codi Tècnic de l'Edificació, que impulsa el disseny basat en prestacions i no en prescripcions, de la no conveniència de deslligar les fases de disseny, s'ha començat per incloure el criteri de la sectorització en el disseny com un objectiu més mesurable en la qualitat de la solució final adoptada, i per tant optimizable com qualsevol altre. Per això en este treball s'ha realitzat una proposta d'algoritme de sectorització, que funciona a partir de la informació i criteris que les normatives d'incendis utilitzen, i s'ha definit també una proposta de funció objectiu, així com una sèrie de paràmetres que permeten considerar com influïx esta sectorització en el trasbals de materials (fonamen-talment fluxos) a través de les distintes activitats. / Jaén Gómez, PI. (2015). Algoritmos híbridos para la resolución del F.L.P. (Facility Layout Problem) basados en colonias de hormigas [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/59447 / TESIS
16

A DECISION SUPPORT SYSTEM FOR MANUFACTURED HOUSING PRODUCTION PROCESS PLANNING AND FACILITY LAYOUT

ABU HAMAD, AYMAN ABDALLAH January 2003 (has links)
No description available.
17

Developing a Methodology for Improving a Mini-Cell System Layout

Patnala, Avinash Kumar 03 October 2011 (has links)
No description available.
18

Facility layout using layout modules

Huang, Heng 15 October 2003 (has links)
No description available.
19

New Approaches for Design of High-Mix Low-Volume Facilities

Khaewsukkho, Smart 25 June 2008 (has links)
No description available.
20

Procedimento para projeto de arranjo físico modular em manufatura através de algoritmo genético de agrupamento / Procedure to the design of modular facility layouts through clustering genetic algorithm

Argoud, Ana Rita Tiradentes Terra 16 March 2007 (has links)
O objetivo desta tese foi desenvolver um procedimento para projeto de arranjo físico modular. O procedimento usa um algoritmo genético de agrupamento para gerar módulos de arranjo físico em manufatura. Um módulo é um grupo de máquinas com um fluxo característico. O algoritmo genético de agrupamento (AGA) permite ao usuário especificar a priori o número desejado de módulos (problema de K-agrupamentos), e também trabalhar de forma que o número e formação dos módulos seja uma otimização do problema (problema de agrupamento automático). Uma característica importante do AGA é sua flexibilidade, pois fornece possibilidade ao usuário de dirigir seu raciocínio através da escolha de diferentes codificações do cromossomo, de funções de aptidão para avaliar a qualidade da solução, de medidas de similaridade para comparação de seqüências de operações e de métodos de geração da nova população. Para tal foram desenvolvidos três operadores de cruzamento e quatro operadores de mutação. Os experimentos permitiram avaliar o comportamento do AGA com diferentes operadores e configurações de parâmetros, através do número de vezes em que a melhor solução foi encontrada. Os módulos de arranjo físico gerados pelo AGA e o arranjo físico final da fábrica foram comparados aqueles da principal referência encontrada na bibliografia em projeto de arranjo físico modular. No arranjo físico final da fábrica, elaborado a partir das soluções do AGA, houve importante redução da distância total percorrida pelo conjunto de peças, demonstrando a eficácia do algoritmo genético de agrupamento. Dessa forma, os resultados apontaram o algoritmo genético de agrupamento como uma alternativa à geração de módulos de arranjo físico em projeto de arranjo físico modular. / The objective of this thesis was the development of a procedure to the design of modular facility layouts. The procedure uses a clustering genetic algorithm to generate layout modules. A module is a group of machines with a specific patterned flow. The clustering genetic algorithm (CGA) allows the specification of the desired number of modules (K-grouping problem) and also the optimization of the number of modules (automatic clustering problem). The genetic algorithm is very flexible and the user can guide his reasoning. It supplies different options of chromosome encoding, generation of the initial population, fitness function to evaluate the solution quality, different similarity measures for comparison of operation sequences and methods for generation of the new population. Three crossover operators and four mutation operators have been developed. The experiments have allowed evaluating the behavior of the CGA with different operators and parameters configurations, through the number of times in which the best solution was found. The layout modules generated by the CGA and the block layout were compared with the main reference which was found in literature in the design of modular facility layouts. In the block layout elaborated from the solutions of the CGA there was an important reduction of the total distance traveled by the set of parts, demonstrating the effectiveness of the clustering genetic algorithm. The results indicated that the clustering genetic algorithm is an alternative for generation of layout modules in the design of modular facility layouts.

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