201 |
Heurística construtiva para a programação de operações flow shop permutacional / A constructive heuristic for scheduling operations flow shop sequencing problemRodrigo Luiz Gigante 21 September 2010 (has links)
Os processos industriais de produção exigem uma programação da produção efetiva. Essa atividade consiste da alocação dos recursos produtivos, a fim de executar tarefas determinadas por um período de tempo definido. Programar a produção é uma das atividades mais complexas do Planejamento da Produção, pois existem diferentes tipos de recursos a serem administrados simultaneamente. E também a quantidade de possíveis soluções aumenta exponencialmente com o aumento da quantidade de tarefas e máquinas presentes no sistema. A proposta deste trabalho é apresentar um método heurístico construtivo para a solução de problemas flow shop permutacional. A função-objetivo utilizada é a minimização do tempo total da programação (makespan). O algoritmo foi desenvolvido com base no melhor algoritmo construtivo presente na literatura, e os resultados obtidos são discutidos e analisados com base na porcentagem de sucesso, desvio relativo médio e tempo médio de computação. / Industrial productive processes demand an effective production scheduling. These activities consist in allocating the productive resources in order to execute determined jobs for a established period of time. Scheduling the production is one of the most complex activities involved in Planning the Production because there are different kinds of resources to be managed simultaneously. Furthermore, the amounts of feasible solutions increase exponentially as the number of jobs and machines in large systems. This dissertation presents a constructive heuristic method to solve the permutational flow shop problem. The evaluation criterion is the total production elapsed time (makespan). The developed algorithm was based on the best algorithm found in the literature, the results are analysed based on the success rate, mean relative deviation and computing time.
|
202 |
Métodos heurísticos construtivos para redução do estoque em processo em ambientes de produção flow shop híbridos com tempos de setup dependentes da seqüência / Constructive heuristics methods to minimizing work in process in environment production hybrid flow shop with asymmetric sequence dependent setup timesMárcia de Fátima Morais 28 May 2008 (has links)
A teoria de programação da produção preocupa-se em fornecer diretrizes e métodos eficientes para a utilização dos recursos nas atividades produtivas. Este trabalho investiga o problema de programação da produção em ambientes flow shop com máquinas múltiplas e tempos de preparação das máquinas assimétricos e dependentes da seqüência de execução das tarefas. A atividade de programação da produção constitui uma das várias funções executadas pelo planejamento e controle da produção, que tem como objetivo comandar e gerenciar o processo produtivo, e caracteriza uma das atividades mais complexas no gerenciamento dos sistemas produtivos. A programação da produção preocupa-se com a alocação de recursos sobre o tempo para executar um conjunto de tarefas. No ambiente estudado neste trabalho as operações de cada tarefa são executadas em múltiplos estágios de produção, podendo variar a quantidade de máquinas em cada um deles. Cada operação é processada por apenas uma máquina em cada estágio. Os tempos de preparação das máquinas possuem uma variabilidade relevante em função da ordem de execução das tarefas nas mesmas. A função-objetivo considerada é a minimização do tempo médio de fluxo. Foram desenvolvidos quatro métodos heurísticos construtivos com base em algoritmos reportados na literatura para solução do problema flow shop permutacional e máquinas paralelas cujo tempo de setup é dependente da seqüência de execução das tarefas. Como não foram encontrados na literatura métodos de solução para o problema investigado neste trabalho, os algoritmos propostos foram comparados entre si. Foi efetuado um estudo da influência da relação entre as ordens de grandeza dos tempos de processamento das tarefas e do setup das máquinas em cada método de solução. Os resultados obtidos na experimentação computacional foram analisados e discutidos com base na porcentagem de sucesso, desvio relativo, desvio-padrão do desvio relativo e tempo médio de computação. / Scheduling theory attempts to provide guidelines and efficient methods to the use of the resources in the productive activities. This study investigates the hybrid flow shop problem with asymmetric sequence dependent setup times. The activity of production scheduling constitute is one of the several functions carried by production planning and control, which has as the objective command and management the production system, and characterize is one of the tasks most complex in production management. This activity of the scheduling aims within the allocation of the resources for the execution of jobs in a time base. In the environment studied in this work, the operations of each job are processed in multiple production stages. The number of machines in each stage can be different. Each operation is processed by only one machine in each stage. The setup times have a significant variability in function of the sequence of job processing on the machines. The objective is minimizing the mean flow time. Four constructive heuristic methods were proposed on the basis of algorithms reported in the literature for solving permutation flow shop and parallel machine problems with sequence dependent setup times. The proposed heuristic methods will have compared between themselves, since no constructive heuristics have been found in the literature for the scheduling problem considered in this work. It was carried out the study of the influence of the relations among the range of the times processing and setup times in each method. The statistics used in order to evaluate the heuristic performances were the percentage of success (in finding the best solution), relative deviation, standard deviation of relative deviation and average computation time. Results from computational experience are discussed.
|
203 |
Test av OCR-verktyg för Linux / OCR software tests for LinuxNilsson, Elin January 2010 (has links)
Denna rapport handlar om att ta fram ett OCR-verktyg för digitalisering av pappersdokument. Krav på detta verktyg är att bland annat det ska vara kompatibelt med Linux, det ska kunna ta kommandon via kommandoprompt och dessutom ska det kunna hantera skandinaviska tecken. Tolv OCR-verktyg granskades, sedan valdes tre verktyg ut; Ocrad, Tesseract och OCR Shop XTR. För att testa dessa scannades två dokument in och digitaliserades i varje verktyg. Resultatet av testerna är att Tesseract är de verktyget som är mest precist och Ocrad är det verktyget som är snabbast. OCR Shop XTR visar på sämst resultat både i tidtagning och i antal korrekta ord. / This report is about finding OCR software for digitizing paper documents. Requirements were to include those which were compatible with Linux, being able to run commands via the command line and also being able to handle the Scandinavian characters. Twelve OCR softwares were reviewed, and three softwares were chosen; Ocrad, Tesseract and OCR Shop XTR. To test these, two document were scanned and digitized in each tool. The results of the tests are that Tesseract is the tool which is the most precise and Ocrad is the tool which is the fastest. OCR Shop XTR shows the worst results both in timing and number of correct words.
|
204 |
Fullständig Njutning : Distinktioner och nyliberal konsumtionskultur i sexbutiken Kino Shops nyhetsbrev 2009-2019Ström, Maya January 2020 (has links)
The sex shop has existed as spatially Othered and ideologically transgressive. However, the last decades have witnessed both a literal and figurative move into a position of normalcy and legitimacy. Previous research conducted on this topic has covered this shift, and the importance of a “feminization” of the market for this to happen. While the previous research is extensive on the “new” sex shop, it has partly overlooked the hybridization of the traditional with the feminized. This essay has thus aimed to discern the trends of a “mixed-gender” sex shop, in order to both contribute to the understanding of the Swedish context as well as how class, gender, and past & present work as distinctions within this. The results show that a stereotypical femininity and masculinity is visually used by the store as tropes of distinction. As abstract ideals they converge in a rhetoric of an aspirational class, that sees knowledge as well as consumption as vital to a “sexual health”. However, while the commodities on offer are partly marketed with such sophistication, they are equally advertised as realistic resemblances of genitalia or parts of the body. Thus, the sophisticated consumption is diversified with a realistic, at times vulgar, address. The conclusive observation here is hence that the traditional sexuality-related consumption can coexist with a feminized version within one and the same store. Consequently, this essay sees that a plurality of desires is a part of the market’s continual expansion.
|
205 |
Rozšíření obchodních aktivit prostřednictvím zavedení e-shopu / Expansion of Business Activities by Introducing an E-shopKučírková, Kateřina January 2021 (has links)
The diploma thesis deals with the development of business activities through the establishment of an e-shop in the company Sýry & Vína VEČERKA. The first part deals with the definition of the problem, the aim of the work and methods of solution. The theoretical part deals with the theoretical basis of the problem. The next part of the work contains an analysis of the internal and external environment, which we then summarize in the SWOT analysis. Based on the results of these analyzes, we will propose a solution to the company that will lead to the development of their business activities.
|
206 |
Návrh dílčí části informačního systému / Proposal of Part of Information SystemBašta, Jiří January 2021 (has links)
This thesis is focused on design and implementation of partial part of the information system in cooperation with the integration of a new agile project management. Partial part of the information system is a web shop for company providing IPTV. This web shop will be implemented in PHP language and Nette framework. The new project management, which will be continously integrated, is agile SCRUM methodology.
|
207 |
Modeling, Analysis, and Algorithmic Development of Some Scheduling and Logistics Problems Arising in Biomass Supply Chain, Hybrid Flow Shops, and Assembly Job ShopsSingh, Sanchit 15 July 2019 (has links)
In this work, we address a variety of problems with applications to `ethanol production from biomass', `agile manufacturing' and `mass customization' domains. Our motivation stems from the potential use of biomass as an alternative to non-renewable fuels, the prevalence of `flexible manufacturing systems', and the popularity of `mass customization' in today's highly competitive markets. Production scheduling and design and optimization of logistics network mark the underlying topics of our work. In particular, we address three problems, Biomass Logistics Problem, Hybrid Flow Shop Scheduling Problem, and Stochastic Demand Assembly Job Scheduling Problem.
The Biomass Logistics Problem is a strategic cost analysis for setup and operation of a biomass supply chain network that is aimed at the production of ethanol from switchgrass. We discuss the structural components and operations for such a network. We incorporate real-life GIS data of a geographical region in a model that captures this problem. Consequently, we develop and demonstrate the effectiveness of a `Nested Benders' based algorithm for an efficient solution to this problem.
The Hybrid Flow Shop Scheduling Problem concerns with production scheduling of a lot over a two-stage hybrid flow shop configuration of machines, and is often encountered in `flexible manufacturing systems'. We incorporate the use of `lot-streaming' in order to minimize the makespan value. Although a general case of this problem is NP-hard, we develop a pseudo-polynomial time algorithm for a special case of this problem when the sublot sizes are treated to be continuous. The case of discrete sublot sizes is also discussed for which we develop a branch-and-bound-based method and experimentally demonstrate its effectiveness in obtaining a near-optimal solution.
The Stochastic Demand Assembly Job Scheduling Problem deals with the scheduling of a set of products in a production setting where manufacturers seek to fulfill multiple objectives such as `economy of scale' together with achieving the flexibility to produce a variety of products for their customers while minimizing delivery lead times. We design a novel methodology that is geared towards these objectives and propose a Lagrangian relaxation-based algorithm for efficient computation. / Doctor of Philosophy / In this work, we organize our research efforts in three broad areas - Biomass Supply Chain, Hybrid Flow Shop, and Assembly Job Shop, which are separate in terms of their application but connected by scheduling and logistics as the underlying functions. For each of them, we formulate the problem statement and identify the challenges and opportunities from the viewpoint of mathematical decision making. We use some of the well known results from the theory of optimization and linear algebra to design effective algorithms in solving these specific problems within a reasonable time limit. Even though the emphasis is on conducting an algorithmic analysis of the proposed solution methods and in solving the problems analytically, we strive to capture all the relevant and practical features of the problems during formulation of each of the problem statement, thereby maintaining their applicability. The Biomass Supply Chain pertains to the production of fuel grade ethanol from naturally occurring biomass in the form of switchgrass. Such a system requires establishment of a supply chain and logistics network that connects the production fields at its source, the intermediate points for temporary storage of the biomass, and bio-energy plant and refinery at its end for conversion of the cellulosic content in the biomass to crude oil and ethanol, respectively. We define the components and operations necessary for functioning of such a supply chain. The Biomass Logistics Problem that we address is a strategic cost analysis for setup and operation of such a biomass supply chain network. We focus our attention to a region in South Central Virginia and use the detailed geographic map data to obtain land use pattern in the region. We conduct survey of existing literature to obtain various transportation related cost factors and costs associated with the use of equipment. Our ultimate aim here is to understand the feasibility of running a biomass supply chain in the region of interest from an economic standpoint. As such, we represent the Biomass Logistics Problem with a cost-based optimization model and solve it in a series of smaller problems. A Hybrid Flow Shop (HFS) is a configuration of machines that is often encountered in the flexible manufacturing systems, wherein a particular station of machines can execute processing of jobs/tasks simultaneously. In our work, we approach a specific type of HFS, with a single machine at the first stage and multiple identical machines at the second stage. A batch or lot of jobs/items is considered for scheduling over such an HFS. Depending upon the area of application, such a batch is either allowed to be split into continuous sections or restricted to be split in discrete sizes only. The objective is to minimize the completion time of the last job on its assigned machine at the second stage. We call this problem, Hybrid Flow Shop Scheduling Problem, which is known to be a hard problem in literature. We aim to derive the results which will reduce the complexity of this problem, and develop both exact as well as heuristic methods in order to obtain near-optimal solution to this problem. An Assembly Job Shop is a variant of the classical Job Shop which considers scheduling a set of assembly operations over a set of assembly machines. Each operation can only be started once all the other operations in its precedence relationship are completed. Assembly Job Shop are at the core of some of the highly competitive manufacturing facilities that are principled on the philosophy of Mass Customization. Assuming an inherent nature of demand uncertainty, this philosophy aims to achieve ‘economy of scale’ together with flexibility to produce a variety of products for the customers while minimizing the delivery lead times simultaneously. We incorporate some of these challenges in a concise framework of production scheduling and call this problem as Stochastic Demand Assembly Job Scheduling Problem. We design a novel methodology that is geared towards achieving the set objectives and propose an effective algorithm for efficient computation.
|
208 |
Brassinoesteroides: síntesi d'anàlegs androstànics encaminats en aprofundir en la interacció brassinoesteroide-receptor.Molist i Fusté, Meritxell 19 April 2007 (has links)
En el camp dels brassinoesteroides, promotors del creixement vegetal, es pretén, d'una banda, aprofundir en el coneixement de la seva interacció amb el receptor (on la formació de ponts d'hidrogen dels diferents hidroxils sembla jugar un paper fonamental) i, de l'altra, obtenir anàlegs amb bona relació cost sintètic-activitat. En aquest sentit, es creu interessant abordar l'estudi dels brassinoesteroides androstànics.Concretament en aquesta tesi, s'han desenvolupat estratègies sintètiques per a l'obtenció, de forma sistemàtica i eficient, d'anàlegs androstànics amb diferents cadenes laterals. S'ha estudiat computacionalment la semblança tridimensional de tots els anàlegs proposats amb la de brassinoesteroides actius de referència, emprant alineaments flexibles amb el programa MOE. Les estratègies desenvolupades per tal d'aconseguir diverses modificacions a l'anell A han permès observar com la introducció de les funcionalitats 2,3-diol és més senzilla i eficient que d'altres a priori interessants com 2,3-difluor o 2,3-dicetona.S'han desenvolupat estratègies i aproximacions per a la síntesi de l'anàleg androstànic que millor simularia la cadena lateral de la brassinolida (brassinosteroide natural més actiu conegut fins el moment). De tota manera, degut a la dificultat sintètica de l'àcid carboxílic 3S,4-dimetil-2R-hidroxipentanoic (cadena lateral) no s'ha aconseguit la síntesi de l'anàleg d'interès. S'han dissenyat, sintetitzat i avaluat una sèrie d'androstans per tal d'estudiar la influència de la part hidrofòbica terminal i de la posició de les funcionalitats polars de la cadena lateral, així com també el paper que juga el grup protector d'aquestes en l'activitat.Amb la finalitat de validar la metodologia SHOP aplicada prèviament en l'equip, s'han sintetitzat i avaluat diversos brassinoesteroides androstànics amb cadenes d'àcids carboxílics comercials escollits emprant aquesta metodologia. La síntesi i avaluació d'activitat d'anàlegs androstànics amb diferents funcionalitats en  de carbonil de la cadena lateral (fluor, carbonil, azida, amina.) així com també la dels anàlegs escollits de forma sistemàtica (metodologia SHOP) ha permès concloure que és necessària la presència d'una funcionalitat donadora de ponts d'hidrogen en aquesta regió per tal que un brassinoesteroide expressi activitat com a promotor del creixement vegetal. / Most of the efforts made nowadays in the field of brassinosteroids, plant growth promoting regulators, are focused on going in depth in the knowledge of the brassinosteroid-receptor interaction (where hydrogen bonding seems to play an important role) and on synthesizing analogs with good cost-activity ratio. In this way, it was considered interesting to study androstane brassinosteroid analogs.In this phD thesis, some synthetic strategies have been developed to obtain androstane analogs with different side chains in a systematic and efficient way. Moreover, the 3D similarity between these analogs and some active brassinosteroids has been studied through flexible alignments using MOE program.The strategies developed to achieve A ring modifications have allowed us to observe how the,3-diol functionality introduction is much more easy and efficient than others such as ,3-difluoro or 2,3-diketone.Lots of trials to synthesize the most similar androstane analog to brassinolide have been made. Unfortunately, due to the synthetic difficulty to obtain 3S,4-dimethyl-2R-hydroxipentanoic acid (side chain) this analog synthesis has been unsuccessful.A group of more than ten brassinosteroid androstane analogs have been designed, synthesized and bioactivity evaluated in order to study the influence of the hydrophobic side chain region, the polar functionality position and the role of some protective groups.With the aim to validate the SHOP methodology, previously applied in our team, some androstane analogs with commercially available side chain have been obtained and bioactivity evaluated.The synthesis and activity evaluation of some analogs with different 2'-functionalities (fluorine, azide, amine...) and of those selected by molecular modeling techniques (SHOP methodology) have let conclude that a hydrogen bond donor group / En el campo de los brasinosteroides, promotores del crecimiento vegetal, se pretende, por un lado, profundizar en el conocimiento de su interacción con el receptor (donde la formación de puentes de hidrógeno de los distintos hidroxilos parece jugar un papel fundamental) y, de otra, obtener análogos con una buena relación coste sintético-actividad. En este sentido, se consideró interesante abordar el estudio de los brasinoesteroides androstánicos.Concretamente en esta tesis, se han desarrollado estrategias sintéticas para la obtención, de forma sistemática y eficiente, de análogos androstánicos con distintas cadenas laterales. Se han estudiado computacionalmente la semejanza tridimensional de todos los análogos propuestos con brasinoesteroides activos de referencia, utilizando alineamentos flexibles con el programa MOE.Las estrategias desarrolladas para conseguir diversas modificaciones en al anillo A han permitido observar como la introducción de las funcionalidades 2,3-diol es más sencilla y eficiente que otras a priori interesantes como 2,3 -difluor o 2,3-dicetona.Se han desarrollado estrategias y aproximaciones para la síntesis del análogo androstánico que mejor simularía la cadena lateral de la brasinolida (brasinoesteroide natural más activo conocido hasta el momento). De todas formas, debido a la dificultad sintética del ácido 3S,4-dimetil-2R-hidroxipentanoico (cadena lateral) no se ha conseguido la síntesis del análogo de interés.Se han diseñado, sintetizado y evaluado una serie de androstanos para estudiar la influencia de la parte hidrofóbica terminal y de la posición de las funcionalidades polares de la cadena lateral, así como también el papel que juega el grupo protector de estas en la actividad.Para validar la metodología SHOP, aplicada previamente en el equipo, se han sintetizado y evaluado diversos brasinoesteroides androstánicos con cadenas de ácidos carboxílicos comerciales escogidos utilizando esta metodología.La síntesis y evaluación de la actividad de análogos androstánicos con distintas funcionalidades en  de carbonilo de la cadena lateral (fluor, azida, carbonilo, amina.) así como también la de análogos escogidos de forma sistemática (metodología SHOP) ha permitido concluir que es necesaria la presencia de una funcionalidad dadora de puente de hidrógeno en esta región para que un brasinoesteroide exprese actividad como promotor del crecimiento vegetal.
|
209 |
Job Sequencing & WIP level determination in a cyclic CONWIP Flowshop with BlockingPalekar, Nipun Pushpasheel 14 September 2000 (has links)
A CONWIP (Constant Work-In-Progress) system is basically a hybrid system with a PUSH-PULL interface at the first machine in the line. This research addresses the most general case of a cyclic CONWIP system by incorporating two additional constraints over earlier studies namely; stochastic processing times and limited intermediate storage. One of the main issues in the design of a CONWIP system is the WIP level 'M', to be maintained. This research proposes an iterative procedure to determine this optimal level. The second main issue is the optimization of the line by determining an appropriate job sequence. This research assumes a 'permutational' scheduling policy and proposes an iterative approach to find the best sequence. The approach utilizes a controlled enumerative approach called the Fast Insertion Heuristic (FIH) coupled with a method to appraise the quality of every enumeration at each iteration. This is done by using a modified version of the Floyd's algorithm, to determine the cycle time (or Flow time) of a partial/full solution.
The performance measures considered are the Flow time and the Interdeparture time (inverse of throughput). Finally, both the methods suggested for the two subproblems, are tested through computer implementations to reveal their proficiency. / Master of Science
|
210 |
Métodos heurísticos para minimização da duração total da programação em ambiente no-wait flow shop com políticas de manutenção-preventiva / Heuristics methods for the no-wait flow shop problem with preventive maintenance constraints and makespan minimizationMiyata, Hugo Hissashi 20 July 2015 (has links)
O problema de programação de operações em ambiente no-wait flow shop tem sido abordado desde a década de 60. Por se tratar de um ambiente em que as tarefas devem ser processadas continuamente e sem interrupções entre uma máquina e outra, um tempo de espera entre o início da tarefa anterior e o início da tarefa atual deve ser determinado na primeira máquina. Neste sentido, uma vez que a tarefa inicia seu processamento, as máquinas devem estar disponíveis para que atendam a restrição de no-wait. Portanto, operações de manutenção preventiva são necessárias para que a programação seja atendida sem maiores problemas. Este trabalho aborda dois problemas: no-wait flow shop e no-wait flow shop com operações de manutenção preventiva. O critério de desempenho adotado foi a duração total da programação (makespan). Por meio de uma revisão de literatura, mecanismos de construção de soluções foram identificadas e classificadas e, baseando-se em tais, novos métodos heurísticos construtivos simples e compostos foram propostos para o problema no-wait flow shop e uma heurística composta foi desenvolvida considerando as operações de manutenção preventiva. Experimentações computacionais para os dois problemas foram realizadas para fins de comparação e avaliação dos métodos propostos com os métodos heurísticos construtivos da literatura. Para o problema Fm|no - wait|Cmax resultados evidenciaram que as heurísticas propostas H4GPSLLS e MH4GPSLLS superaram as heurísticas da literatura em qualidade de solução, com diferença estatisticamente significativa no nível de 5% de significância. Para o problema Fm|no - wait, m(k)|Cmax, pode-se constatar que a heurística BIHLS e as heurísticas H4GPSLLS e MH4GPSLLS apresentaram desempenho superior com diferença estatística significativa no nível de 5% de significância em comparação as heurísticas da literatura. / The no-wait flow shop scheduling problem has been studied since 60\'s. In this environment, jobs must be processed continuously without interruption between one machine and another, and because of this, a delay between the start time of the previous job and the start time of the current job must be determined in the first machine. In this sense, since a job starts its processing, the machines must be available to respect the no-wait constraint. Therefore, preventive maintenance operations are needed. This work adresses two problems: the m machine no-wait flow shop and the m machine no-wait flow shop with preventive maintenance operations. The performance measure adopted was the makespan. By means of a literature review, mechanisms of solution construction were identified and classified. New simple and composite constructive heuristics were proposed to the no-wait flow shop problem and a new composite constructive heuristic was developed considering the preventive maintenance operations. Computational experiments and their respective analyses for both problems were carried out to compare and evaluate the performance between the proposed methods and the constructive heuristics of the literature. Regarding Fm|no - wait|Cmax problem, results show that the proposed heuristics H4GPSLLS and MH4GPSLLS outperformed the heuristics of the literature in quality of the solution and is statistically significative to 5% of significance level. To the Fm|no - wait, m(k)|Cmax problem it can be seen that the proposed heuristic BIHLS and H4GPSLLS and MH4GPSLLS outperformed the heuristics of the literature and is statistically better to 5% of significance level.
|
Page generated in 0.0322 seconds