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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.
241

Aplicação de algoritmos genéticos para minimização do número de objetos processados e o setup num problema de corte unidimensional / Analysis of cutting stock problem using genetic algorithm

Julliany Sales Brandão 22 May 2009 (has links)
Esta dissertação apresenta a aplicação de uma nova abordagem utilizando Algoritmo Genético na resolução do Problema de Corte Unidimensional na minimização de dois objetivos, geralmente conflitantes, o número de objetos processados e o setup, simultaneamente. O problema de corte consiste, basicamente, em encontrar a melhor maneira de obter peças de tamanhos distintos (itens) a partir do corte de peças maiores (objetos) com o objetivo de minimizar alguma espécie de custo ou maximizar o lucro. A disposição dos itens no objeto para a realização de cortes durante sua produção é denominada padrão de corte. E o setup é o tempo de preparação de máquina. O modelo do problema, a função objetivo e o método proposto denominado SingleGA, bem como os passos utilizados para sua resolução, também são apresentados. Os resultados obtidos pelo SingleGA são comparados com os métodos SHP, Kombi234, ANLCP300 e Symbio, encontrados na literatura, a fim de verificar a capacidade de encontrar soluções viáveis e competitivas. Os resultados computacionais mostram que o método proposto, o qual utiliza apenas um algoritmo genético para resolver esses dois objetivos inversamente relacionados, proporciona bons resultados.
242

O alinhamento do pensamento estratégico: o Balanced Scorecard como condutor do processo na Caixa Econômica Federal

Flores, Edson Luiz 04 January 2008 (has links)
Este trabalho tem como objetivo verificar se a adoção dos conceitos do BSC (Balanced Scorecard) na avaliação da gestão das unidades de negócio da Caixa Econômica Federal está contribuindo para que ocorra o alinhamento do pensamento estratégico nos diversos níveis gerenciais da organização. Com tal finalidade, foi realizada uma pesquisa junto a três grupos de profissionais com atuação na gestão das unidades de negócio da empresa na região da Superintendência Regional da Serra Gaúcha. Este trabalho apresenta o resultado da pesquisa que desenvolveu o instrumento de coleta de dados, seguindo o método de escalas multiitens. A escala foi construída a partir da realidade da organização selecionada como campo de estudo e, para tanto, fundamentou-se nos sete desafios estratégicos para o período 2005-2015. Após a revisão de literatura, a aplicação da pesquisa e a análise dos dados discutiram-se o alinhamento estratégico a partir da adoção do BSC, bem como a sua influência nos resultados da Caixa Econômica Federal. Verificou-se que, sob todos os aspectos analisados, a adoção do BSC está contribuindo para que ocorra o alinhamento do pensamento estratégico dos gestores da Caixa Econômica Federal que atuam em níveis hierárquicos e funcionais diferentes dentro da organização. Além disso, constatou-se que o resultado líquido da empresa estudada evolui acima da média dos seus maiores concorrentes. / This work has as its objective to verify if the adoption of the concepts of BSC (Balanced Scorecard) in the management evaluation of the business units of Caixa Econômica Federal is contributing to standardize the strategic thought in the several management levels of the organization. With such purpose, a research was carried out with three groups of professionals that act in the administration of the business units of the company, in the Superintendency Area of Serra Gaucha. The current work presents the research result that developed an instrument of data collection following the method of scales multiitens. The scale was built starting from the reality of the organization selected as study field and it was based in the seven strategic challenges for the period 2005-2015. After the literature revision, the application of the research and the data, the strategic standardization starting from the adoption of BSC is discussed, as well as its influence in the results of Caixa Econômica Federal. It was checked that, under all analyzed aspects, the adoption of BSC is contributing for the alignment of the bank strategic thought of the managers` of Caixa Econômica Federal that act in different hierarchical and functional levels inside the organization. Besides, it was checked that the net income of the studied company grows above the average of its largest competitors.
243

Comparação de abordagens MOPSO no planejamento da operação de sistemas hidrotérmicos / Comparing MOPSO approaches for hydrothermal systems operation planning

Silva, Jonathan Cardoso 26 February 2014 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2015-01-27T14:37:37Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - Jonathan Cardoso Silva - 2014.pdf: 3627934 bytes, checksum: 4b576bd42a95d94493a78b1e54c2d64a (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-01-28T12:39:13Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - Jonathan Cardoso Silva - 2014.pdf: 3627934 bytes, checksum: 4b576bd42a95d94493a78b1e54c2d64a (MD5) / Made available in DSpace on 2015-01-28T12:39:13Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - Jonathan Cardoso Silva - 2014.pdf: 3627934 bytes, checksum: 4b576bd42a95d94493a78b1e54c2d64a (MD5) Previous issue date: 2014-02-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The operation planning of hydrothermal systems is a complex, dynamic, stochastic, nonlinear and interconnected problem. In this study, we consider that this problem must tackle two objectives simultaneously: minimize thermoelectric generation (by maximizing the use of hydroelectric plants) and maximize water reservoirs’ level of hydroelectric plants. This dissertation presents the application of some multiobjective meta-heuristics, using a set of eight actual plants from Brazilian interconnected system in three periods of medium-term planning. The algorithms used were of two types: those based on particle swarms (MOPSO , MOPSO-TVAC , SMPSO, MOPSO-CDR and MOPSO-DFR) and evolutionary algorithms (SPEA2 and MOEAD/DRA). The results from previous studies, made with single objective techniques, were inserted in the initial population of the algorithms and compared with those simulations with normal initialization. We observed that MOPSO-CDR outperformed the other algorithms in the test scenarios while, in some cases, MOPSO has also generated competitive results. / O problema do planejamento da operação de sistemas hidrotérmicos é complexo, dinâmico, estocástico, interconectado e não linear. Este problema é tratado de modo atender a dois objetivos simultaneamente: maximizar a geração elétrica nas usinas hidrelétricas (ou minimizar o custo com a complementação da geração por termelétricas) e maximizar o nível dos reservatórios de água das hidrelétricas. Este trabalho apresenta a aplicação de algumas meta-heurísticas multiobjetivo a este problema, utilizando um conjunto de oito usinas reais do Sistema Interligado Nacional em três períodos de planejamento de médio prazo. Os algoritmos utilizados foram de dois tipos: os baseadas em enxames de partículas (MOPSO, MOPSO-TVAC,SMPSO, MOPSO-CDR e MOPSO-DFR) e os algoritmos evolucionários (SPEA2 e MOEAD/DRA). Foram realizados testes com a inserção de resultados de estudos anteriores com técnicas de único objetivo na população inicial dos algoritmos e comparados com os testes com inicialização normal. Observou-se que o algoritmo MOPSO-CDR obtém os melhores resultados nos cenários de testes utilizados, competindo em alguns casos com os resultados do MOPSO.
244

Otimização de sistemas hidrotérmicos de geração por meio de meta-heurísticas baseadas em enxame de partículas / Optimization of hydrothermal generating systems by means of particle swarm based meta-heuristics

Deus, Guilherme Resende 02 February 2016 (has links)
Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2017-07-03T12:59:51Z No. of bitstreams: 2 Dissertação - Guilherme Resende Deus - 2016.pdf: 3406372 bytes, checksum: aaa431a0fa0dd2323a74cf35fb63f892 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-07-10T11:44:22Z (GMT) No. of bitstreams: 2 Dissertação - Guilherme Resende Deus - 2016.pdf: 3406372 bytes, checksum: aaa431a0fa0dd2323a74cf35fb63f892 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-07-10T11:44:22Z (GMT). No. of bitstreams: 2 Dissertação - Guilherme Resende Deus - 2016.pdf: 3406372 bytes, checksum: aaa431a0fa0dd2323a74cf35fb63f892 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-02-02 / The objective of this work is to find reasonable solutions to the problem of optimization of hydrothermal generating systems by means of metaheuristics based on particle swarms. The proposed problem is complex, dynamic, nonlinear and presents some stochastic variables. The study consisted of the implementation of particle swarm algorithms, more specifically the variants of the Particle Swarm Optimization (PSO) algorithm: LSSPSO, ABeePSO and KFPSO. The algorithms were run in a mill simulator containing data from eight National Interconnected System mills during the five year period. The results were compared with the studies using the Nonlinear Programming (NLP) algorithm, and it was concluded that although the presented meta-heuristics were able to obtain a Final Storage Energy value equal to NLP, they did not have a generation cost Equivalent to or less than the Nonlinear Programming method. / O trabalho objetiva encontrar soluções razoáveis para o problema de otimização de sistemas hidrotérmicos de geração por meio de meta-heurísiticas baseadas em enxame de partículas. O problema proposto é complexo, dinâmico, não linear e apresenta algumas variáveis estocásticas. O estudo consistiu na implementação de algoritmos baseados em enxame de partículas, mais especificamente das variantes do algoritmo Particle Swarm Optimization (PSO): LSSPSO, ABeePSO e KFPSO. Os algoritmos foram executados em um simulador de usinas que contém dados de oito usinas do Sistema Interligado Nacional durante o período de cinco anos. Os resultados foram comparados com os estudos que utilizam o algoritmo de Programação Não-Linear (PNL), e conclui-se que apesar de as meta-heurísticas apresentadas conseguirem obter um valor de Energia Armazenada Final igual ao PNL, não obtiveram um custo de geração equivalente ou inferior ao método de Programação Não-Linear.
245

Rumo a um desenho técnico de um sistema de apoio à decisão para uma reconfiguração do soft systems methodology: o caso do planejamento sistêmico

Maranhão Filho, Éfrem de Aguiar 07 February 2013 (has links)
Submitted by Efrem Maranhão Filho (efremfilho@gmail.com) on 2013-03-08T18:52:46Z No. of bitstreams: 1 teseDoutoradoEfrem.pdf: 4695587 bytes, checksum: 70cbab7e35da687c5b0830b63dcd7115 (MD5) / Approved for entry into archive by Vera Lúcia Mourão (vera.mourao@fgv.br) on 2013-03-08T19:45:46Z (GMT) No. of bitstreams: 1 teseDoutoradoEfrem.pdf: 4695587 bytes, checksum: 70cbab7e35da687c5b0830b63dcd7115 (MD5) / Made available in DSpace on 2013-03-08T19:46:31Z (GMT). No. of bitstreams: 1 teseDoutoradoEfrem.pdf: 4695587 bytes, checksum: 70cbab7e35da687c5b0830b63dcd7115 (MD5) Previous issue date: 2013-02-07 / Multidisciplinary in decision-making undergoes the same specificities of any multidisciplinary field. Very often, the lack of communication generates problems and some different approaches can be found in other areas of expertise. The Problem Structuring Methods offers answers for current queries in business administration schools, being particularly useful when used in a multimethodological approach with others current methods. Having the Soft Systems Methodology – SSM – as the core, and the merged with Strategic Options Development and Analysis in the process, Georgiou (2012) presents the Systemic Planning in the latest configuration. Aiming to seek a computational tool that meets the assumptions of the SSM, and which incorporates the specifications of the configuration of Systemic Planning, here are defined a Notation for the method and a formalization of the existing communications between the elements, subsystems, system and environment and thus find a possible way of control the use of the method in a iteratively mode. In order to demonstrate such use of the Systemic Planning, A real case analysis is presented and shows the difficulties encountered in using the Notation defined and the Formalization of the communication. Subsequently, a design of a modular computational tool, and which can be used integrated with other tools of other methods, is presented. The contribution achieved are advances in the patterns in the use of SSM tools, presented the systemic aspects of the Systemic Planning, a demonstration of the iterative use and a blueprint for a computer tool. / A multidisciplinaridade da tomada de decisão sofre com as peculiaridades de qualquer campo multidisciplinar. A falta de comunicação, muitas vezes, gera problemas e as respostas que podem ser encontradas dentro de outras áreas. Os Métodos de Estruturação de Problemas são respostas para os questionamentos atuais nas escolas de administração e negócios, principalmente o uso multimetodológico destes com outros métodos. Tendo o Soft Systems Metholodogy – SSM – como base, e a incorporação do Strategic Options Development and Analysis – SODA – ao processo do SSM, Georgiou (2012) apresenta o Planejamento Sistêmico em sua configuração mais recente. Visando buscar uma ferramenta computacional que atenda os pressupostos do SSM, e que incorpore as especificações da configuração do Planejamento Sistêmico, definem-se uma notação para o método e uma formalização das para as comunicações existentes entre os elementos, subsistemas, sistema e ambiente e, com isso, torna-se possível controlar o uso do método de forma iterativa. Para demonstrar tal uso, apresenta-se uma análise de um caso real e demonstra as dificuldades encontradas na utilização da Notação e Comunicação definida. Posteriormente, apresenta-se um desenho técnico de uma ferramenta computacional modular e que pode ser usada de forma integrada com outras ferramentas de outros métodos. Como resultado, têm-se o avanço na definição de padrões no uso das ferramentas do SSM, na apresentação dos aspectos sistêmicos do Planejamento Sistêmico, na apresentação de um uso iterativo do método e na apresentação de um desenho técnico para uma ferramenta computacional.
246

Méta-enseignement : génération active d’exemples par apprentissage par renforcement

Larocque, Stéphanie 05 1900 (has links)
Le problème d’intérêt est un problème d’optimisation discrète dont on tente d’approximer les solutions des instances particulières à l’aide de réseaux de neurones. Un obstacle à résoudre ce problème par apprentissage automatique réside dans le coût d’étiquettage élevé (et variable) des différentes instances, rendant coûteuse et difficile la génération d’un ensemble de données étiquettées. On propose une architecture d’apprentissage actif, qu’on nomme architecture de méta-enseignement, dans le but de pallier à ce problème. On montre comment on combine plusieurs modèles afin de résoudre ce problème d’apprentissage actif, formulé comme un problème de méta-apprentissage, en utilisant un agent d’apprentissage par renforcement pour la génération active d’exemples. Ainsi, on utilise des concepts de plusieurs domaines de l’apprentissage automatique dont des notions d’apprentissage supervisé, d’apprentissage actif, d’apprentissage par renforcement, ainsi que des réseaux récurrents. Dans ce travail exploratoire, on évalue notre méthodologie sur un problème simple, soit celui de classifier des mains de poker en 10 classes pré-établies. On teste notre architecture sur ce problème jouet dans le but de simplifier l’analyse. Malheureusement, l’avantage d’utiliser l’architecture de génération active n’est pas significatif. On expose ensuite plusieurs pistes de réflexion sur certaines observations à approfondir dans de futurs travaux, comme la définition de la fonction de récompense. Dans de futurs projets, il serait également intéressant d’utiliser un problème plus similaire au problème d’optimisation initial qui comporterait, entre autres, des coûts d’étiquettage variables. / The motivating application behind this architecture is a discrete optimisation problem whose solution we aim to predict using neural networks. A main challenge of solving this problem by machine learning lies in the high (and variable) labelling cost associated to the various instances, which leads to an expensive and difficult dataset generation. We propose an active learning architecture, called meta-teaching, to address this problem. We show how we combine several models to solve the active learning problem, formulated as a metalearning problem, by using a reinforcement learning agent to actively generate new instances. Therefore, we use concepts from various areas of machine learning, including supervised learning, active learning, reinforcement learning and recurrent networks. In this exploratory work, we evaluate our method on a simpler problem, which is to classify poker hands in 10 predefined classes. We test our architecture on this toy dataset in order to simplify the analysis. Unfortunately, we do not achieve a significant advantage using our active generation architecture on this dataset. We outline avenues for further reflections, including the definition of the reward function. In future projects, using a more similar problem to our problem of interest having, among others, a variable labelling cost, would be interesting.
247

Simulation of 48-Hour Queue Dynamics for A Semi-Private Hospital Ward Considering Blocked Beds

Chen, Wei 23 March 2016 (has links)
This thesis study evaluates access to care at an internal medicine unit with solely semi-private rooms at Baystate Medical Center (BMC). Patients are divided into two types: Type I patient consumes one bed; Type II patient occupies two beds or an entire semi-private room as a private space for clinical reasons, resulting in one empty but unavailable (blocked) bed per Type II patient. Because little data is available on blocked beds and Type II patients, unit-level hospital bed planning studies that consider blocked beds have been lacking. This thesis study bridges that gap by building a single-stream and a two-stream discrete micro-simulation model in Excel VBA to describe unit-level bed queue dynamics at hourly granularity in the next 48-hour time horizon, using historical arrival rates and census-dependent discharge rates, supplemented with qualitative results on complexity of patient-level discharge prediction. Results showed that while we increase additional semiprivate beds, there was notable difference between the traditional single-stream model and the two-stream model concerning improvement in bed queue size. Possible directions for future research include patient-level discharge prediction considering both clinical and nonclinical milestones, and strategic redesign of hospital unit(s) considering overflows and internal transfers.
248

Modeling of Electrical Grid Systems to Evaluate Sustainable Electricity Generation in Pakistan

Amjad, Muhammad Mustafa 15 July 2020 (has links)
Pakistan has always had a history of severe energy shortfalls, which rose up to an alarming 33% in 2013. This situation was countered by investments in the energy sector through the China Pakistan Economic Corridor (CPEC), which were unfortunately largely based on brown fuels. Although beneficial in the short term, these investments do not bode well for the climate scenario of Pakistan, with various parts of the country already having experienced temperatures rise of 1-3°C. To ensure that the current situation doesn’t exacerbate and is tackled in a timely manner, this research aims to examine how the untapped potential of renewable energy in Pakistan can be better utilized by modelling the entire electrical grid system for multi-portfolio based sustainable electricity generation, in line with the sustainable development goals chalked out by Pakistan with the United Nations (UN). Delving further into the matter, a gap is observed that demands coalescence between sustainability and portfolio-based generation in the context of Pakistan, since the prevalent narrative is of Business As Usual (BAU). The research methodology implemented is a cross sectional case study employing qualitative and quantitative data collection methods and outcomes, in which the entire grid system of Pakistan is studied and sustainability metrics are defined; followed by a comprehensive use of Multi-Criteria Decision Methodology in decision making process. Portfolios defined are a combination of different generation technologies, each simulating a possible avenue of policy, and are then evaluated for a range of sustainability metrics to understand the tradeoffs involved to arrive at a set goal. The process decision framework developed shall enable the Pakistani energy sector in meeting the energy demands by providing the decision-makers with various routes to do so, while informing on the sustainability impact of their decisions.
249

Multi-Criteria Decision Modeling for Best Value Selections in Target Value Design Integrated Project Delivery

Griffis, Brent Patrick 01 June 2014 (has links)
Integrated Project Delivery (IPD) combined with Target Value Design (TVD) is a better way to deliver value for the client than traditional guaranteed maximum price (GMP) methods. With traditional GMP delivery methods, the interests of the parties are often at odds. The goal of IPD is to align all party interests in order to achieve a win-win scenario. Due to the aligning nature of IPD and the fact that each party’s success is dependent on achieving the project objectives as a whole; a non-biased, transparent, decision-making process is necessary in order to deliver the project objectives within the constraints of the TVD. Thus delivering the expected value for the client and ensuring that all parties achieve project success. The need for this transparent decision-making process is compounded by the fact that a “target” based system rapidly declines to a less than optimal state if there is no unbiased decision-making process in place. If we treat the entire lifespan of a project as the complex system that it is, we can begin to take advantage of the hierarchical nature of complex systems. The goal of this paper is to show that by modeling the life span of a project through a multi-criteria decision making model, built on a hierarchical framework will allow you to find a non-inferior solution to your TVD. I’m proposing to use Hierarchical Holographic Modeling (HHM) as the framework for an Analytical Hierarchical Process (AHP) multi-criteria decision-making model complete with post-optimality analysis as the preferred project management method.
250

An inclusion of value leaks into earned value analysis as a measure of project management

Asiedu, Ernest Marfo 11 1900 (has links)
This study originally emanated from the debate on value creation through projects, which has become more prevalent in project management literature in recent times. Earned value analysis, which is widely used to measure and report the performance of project value, does not include the occurrence of value leaks in its calculations and reporting. Although there is a scarcity of literature on the issue of value leaks during project deployment, it is considered to be a big issue which can make or break a project’s value success. This lack of research is more pronounced in network expansion projects in the Ghanaian telecommunication industry, however, considering the level of investment by these network operators, and their contribution to economic growth, the occurrence of value leaks can be suspected. Therefore, the overall aim of the study was to develop a diagnostic model that aids in the easy identification of value leaks, so that they can be controlled, and remedied to minimise the forgone unrealised project value. In view of this, the study adopted an exploratory sequential mixed research design. The qualitative phase employed a multiple-case study approach to explore the concept of value leaks and the extent to which it becomes problematic in delivering overall project value. The quantitative phase, through a survey study, adopted factor analysis to test and validate the findings from the case study, and analyses were also performed to test the conceptual model fit to the retained dataset. The findings culminated in the development of the “Value Leaks-Flashlight”, with an add-on called the “Tolerable Nut” to theorise the concept of value leaks. This practical establishment of the value leak concept cemented the development of the value leaks diagnostic model through the application of the “CIIR” acronym, which fulfils the overall aim of the study. The study contributes to the contemporary literature in the field of project management, as the concept of project value leaks is still gaining prominence, and only a few empirical studies have thus far been conducted. The concept of value leaks enlightens the perspective of project management practitioners in their quest to achieve value through projects. / Business Management / D. Phil. (Management Studies)

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