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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

Study on Architecture-Oriented Electric Arc Furnace Manufacturing System Model

Huang, Bo-ham 25 June 2009 (has links)
The electric arc furnace steelmakers produce steel across wide ranging sizes and different quality levels. The method of using electric arc for melting is an important process to produce steel from iron or scraps. The diversity of products and markets makes the steelmakers to operate within a large number of constraints of limited enterprise resources, so the electric arc furnace manufacturing system faces problems to integrate the enterprise resource planning system with the manufacturing execution system. The international automation society has come out a solution with an international standard, also known as ISA-95 aimed to help manufacturing industries such as electric arc furnace steelmakers, for the integration of enterprises and control systems. However, ISA-95 only emphasizes on the integration of enterprises and control systems, but does not provide a whole picture of the entire system. This research utilizes the tool of system architecture to develop the architecture-oriented electric arc furnace manufacturing system model, abbreviated as AOEAFMSM, to illustrate coherently the structure view and the behavior view of the electric arc furnace manufacturing system. Furthermore, AOEAFFMSM is able to fully describe many other views of the electric arc furnace manufacturing system. This capability satisfies everybody¡¦s need for capturing different views of the system. Consequentially, AOEAFFMSM simplifies the software development and reduces many communication difficulties among system developers and customers. In modeling the electric arc furnace manufacturing system model, AOEAFFMSM is superior to ISA-95.
22

On Manufacturing System Development in the Context of Concurrent Engineering

Aganovic, Dario January 2004 (has links)
<p>This thesis presents an extension of the contemporaryengineering design theory towards a unified view onsimultaneous development of products and manufacturing systems,i.e. concurrent engineering.</p><p>The traditional engineering design theory explains therealization of a product design as a development of productstructure from four perspectives: technical process, function,technical solution, and physical embodiment. This thesisextends the engineering design theory with a set of definitionsand universal statements. These definitions and universalstatements describe manufacturing systems from same fourperspectives. In that context they also describe therelationship between a product and its manufacturing system.The thesis contributes to the creation of a single theoreticalsystem based on an integration of theories from two engineeringdesign schools, the WDK and the Axiomatic Design. WDKtheoriesare in this new context utilized for qualitative synthesis ofthe developed artifacts, while the Axiomatic Design is utilizedfor structuring and analyzing the corresponding quantitativeparameters.</p><p>The definitions and universal statements describe thedevelopment structures for productsand manufacturing systems.This description is utilized for definition of a system fordevelopment of these structures, i.e. (i) a stage-gate-basedmanufacturing system development process, (ii) a developmentmethodology toolbox, and (iii) an information managementframework consisted of an information model harmonized with thesystems engineering data management standard STEP AP 233.</p><p>The research has been carried out in a close collaborationwith Swedish manufacturing industry. The utilized researchmethodology is the hypothetic- deductive method, with casestudy as an observation method.</p><p><b>Keywords:</b>Concurrent Engineering, Engineering Design,Development Methods and Tools, Manufacturing System,Information Management.</p>
23

Mechaninių gaminių integruotos gamybos sistemos modelio sukūrimas / Integrated model of manufacturing system for mechanical products

Borusas, Henrikas 29 September 2008 (has links)
Baigiamajame magistro darbe pateikiamos teorinės integruotos gamybos sistemos galimybės ir prielaidos, įdiegimo funkcijos ir etapai. Analizuojamos integruotos gamybos sistemos integravimo praktinės galimybės realiam mechaniniam gaminiui, nurodoma laukiama nauda ir kiti privalumai. / The practical realization of model theoretical bases to medium Lithuanian company X is carried out. Considered company in manufacturing business of small trucks components’ is involved. It applies the various metal profiles as materials and machining, welding and painting operations. The company business process was modeled, tested and validated. It works on the virtual prototypes at the early business conception stage. Main task of developed model in this stage is forecasting of manufacturing cost and decision making selecting suppliers and partners. The results and conclusions of work are presented.
24

QUALITY ANALYSIS IN FLEXIBLE MANUFACTURING SYSTEMS WITH BATCH PRODUCTIONS

Wang, Junwen 01 January 2010 (has links)
To improve product quality and reduce cost, batch production is often implemented in many exible manufacturing systems. However, the current literature does not provide any method to analyze the quality performance in a flexible manufacturing system with batch production. In this research, we present an analytical method with closed-form formula to evaluate the quality performance in such systems. Based on the model, we discover and investigate monotonic and non-monotonic properties in quality to provide practical guidance for operation management. To improve product quality, we introduce the notions of quality improvability with respect to product sequencing. In addition, we develop the indicators for quality improvability based on the data available on the factory floor rather than complicated calculations. We define the bottleneck sequence and bottleneck transition as the ones that impede quality in the strongest manner, investigate the sensitivity of quality performance with respect to sequences and transitions, and propose quality bottleneck sequence and transition indicators based on the measured data. Finally, we provide a case study at an automotive paint shop to show how this method is applied to improve paint quality. Moreover, we explore a potential application to reduce energy consumption and atmospheric emissions at automotive paint shops. By selecting appropriate batch and sequence policies, the paint quality can be improved and repaints can be reduced so that less material and energy will be consumed, and less atmospheric emissions will be generated. It is shown that such scheduling and control method can lead to significant energy savings and emission reduction with no extra investment nor changes to existing painting processes. The successful development of such method would open up a new area in manufacturing systems research and contribute to establish a solid foundation for an integrated study on productivity, quality and exibility. In addition, it will provide production engineers and operation managers a quantitative tool for continuous improvement on product quality in flexible manufacturing environment
25

Job Scheduling Considering Both Mental Fatigue and Boredom

Jahandideh, Sina 25 January 2012 (has links)
Numerous aspects of job scheduling in manufacturing systems have been the focus of several studies in the past decades. However, human factors in manufacturing systems such as workers’ mental conditions are still neglected issues and have not received adequate attentions. Job boredom and mental fatigue are both aspects of workers’ mental condition. They affect work performances by increasing sick leave duration and decreasing work productivity. On the other hand, job rotation could be an alternative strategy to cope with such human issues at work. The benefits of job rotation for both employees and firms have been widely recognized in the literature. Although some studies found job rotation as a means to reduce workers' physical work-related traumas, they did not consider the effect of variable mental conditions on workers. Despite the proven importance of boredom and mental fatigue at the workplace, they have not been a combined precise objective of any job rotation problem in current literature. The study of mental conditions proposed in this paper attempts to extend the previous works by addressing new methods and developing a feasible solution to increase manufacturing productivity. A new job scheduling program has been designed specifically which combines a new job rotation model and a job assignment method.
26

Development of a toolkit for component-based automation systems

McLeod, Charles S. January 2013 (has links)
From the earliest days of mass production in the automotive industry there has been a progressive move towards the use of flexible manufacturing systems that cater for product variants that meet market demands. In recent years this market has become more demanding with pressures from legislation, globalisation and increased customer expectations. This has lead to the current trends of mass customisation in production. In order to support this manufacturing systems are not only becoming more flexible† to cope with the increased product variants, but also more agile‡ such that they may respond more rapidly to market changes. Modularisation§ is widely used to increase the agility of automation systems, such that they may be more readily reconfigured¶. Also with globalisation into India and Asia semi-automatic machines (machines that interact with human operators) are more frequently used to reduce capital outlay and increase flexibility. There is an increasing need for tools and methodologies that support this in order to improve design robustness, reduce design time and gain a competitive edge in the market. The research presented in this thesis is built upon the work from COMPAG/COMPANION (COMponent- based Paradigm for AGile automation, and COmmon Model for PArtNers in automatION), and as part of the BDA (Business Driven Automation), SOCRADES (Service Oriented Cross-layer infrastructure for Distributed smart Embedded deviceS), and IMC-AESOP (ArchitecturE for Service- Oriented Process – monitoring and control) projects conducted at Loughborough University UK. This research details the design and implementation of a toolkit for building and simulating automation systems comprising components with behaviour described using Finite State Machines (FSM). The research focus is the development of the engineering toolkit that can support the automation system lifecycle from initial design through commissioning to maintenance and reconfiguration as well as the integration of a virtual human. This is achieved using a novel data structure that supports component definitions for control, simulation, maintenance and the novel integration of a virtual human into the automation system operation.
27

A contribution to the development of a HMS simulation tool and proposition of a meta-model for holonic control

Simão, Jean Marcelo 10 2011 (has links)
The present context and tendencies in modern production system, as mass customization, requires improvements with respect to the agility of the production organizations. In this sense, agile approaches have been proposed, such as the holonic approach. In Holonic Manufacturing System (HMS) the production entities, as resources and products, are envisaged with a type of intelligence. These smart-entities are called holons (HLs) whose intelligence is related to their autonomy and collaboration skills. The HMS also comprises a Holonic Control (HC) that must properly organize holon collaborations in order to become agile. Actually, HMS development requires engineering tools for design and testing. In this doctoral thesis, a meta-model for HC is proposed, whose instances are simulated within a particular tool called ANALYTICE II. This tool presents a clear separation between high-level control and emulated resources. Firstly, before the proposition of the HC meta-model, the resource holonification is proposed in this environment. Each Resource-HL is obtained by means of a virtual resource that provides data and services of an emulated-resource at a high level of control. Subsequently, the meta-model for HC over Resource-HLs following a process-driven production approach is proposed. The essence of the solution is based on Rule Base System (RBS) concepts being the causal relations of control dealt with by entities called Rules. The inference process in this RBS is realized through collaborations based upon notifications. The Resource-HLs notify the Rules about factual knowledge with respect to their states. Each Rule that is notified deliberates about the proper moment to execute some control action, as the coordination of a set of Resource-HLs, using causal knowledge. The inference occurs within a notification chain enabled by a group of Resource-HL agents and Rule agents. This kind of inference can be expected to provide advantages for the HC, such as high reactivity and entity decoupling. Furthermore, it allows for the creation of co-operative mechanisms for dealing with determinism and conflict issues. Moreover, this approach of rule-oriented control allows for coherent control implementation and expression. The control mechanisms emerge based on causal control knowledge expressed by experts in the Rules. Experts are exclusively concerned with the proper control knowledge needed for exploiting system flexibilities in order to increase system agility. Furthermore, some experts could even be artificial agents automatically dealing with knowledge of the Rules. Briefly, this process-driven HC solution concomitantly treats a set of control issues while also being a self-contained and open solution. Indeed, the solution openness allows its interpretation as a product-driven solution. The product-driven control is a tendency to reach agility by the decoupling of production demands and execution via entities like Smart-Product-HLs. Each Smart-Product-HL is concerned with a specific customized production order. The Smart-Product-HLs, with certain autonomy, use Resource-HLs to reach their production goals. In the meta-model interpretation, their interactions are organized by Rules for Resource-HL cooperation that avoids inappropriate system behavior. In this context, the execution of Rules depends upon the explicit Smart-Product-HL interest in their utilization. In some manner, each Smart-Product- HL deals with Rules as a kind of expert agent. The solution has been applied in a set of examples in ANALYTICE II presenting some simulation independence because each control instance is not aware that Resource-HLs and Smart-Product-HLs are simulated.
28

Analise de margem de contribuição e capacidade produtiva pro programação linear e simulação para apoio a tomada de decisão num sistema de manufatura / Contribuition margin and productive capacity analysis through linear programming and simulation for decision support in a manufacturing system

Nakayama, Alexandre Yamassaki 29 July 2005 (has links)
Orientador: Sergio Tonini Button / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-06T07:50:50Z (GMT). No. of bitstreams: 1 Nakayama_AlexandreYamassaki_M.pdf: 678284 bytes, checksum: fe25f524e1f87976fd997d7050c64bdb (MD5) Previous issue date: 2005 / Resumo: A competição cada vez mais acirrada do mundo globalizado exige das empresas o estudo e uso de ferramentas, teorias e conceitos que auxiliem no aumento de produtividade. Dentre os muitos sistemas administrativos e métodos de auxílio de aumento de produtividade, a Pesquisa Operacional tem se mostrado bastante eficiente e difundida pelos tomadores de decisões. Na Pesquisa Operacional, destacam-se especialmente as técnicas de Simulação e Programação Linear, técnicas que se desenvolveram em paralelo ao desenvolvimento da informática, esta tão presente no mundo atual. Este trabalho tem o objetivo principal de comparar a abordagem de um problema de programação da manufatura por estas técnicas distintas em um ambiente produtivo responsável pela fabricação de peças forjadas e usinadas para o setor automobilístico. O resultado esperado deste estudo é facilitar o entendimento e explicitar a diferença das duas técnicas englobando principalmente a aquisição e tratamento dos dados para uma escolha mais apurada / Abstract: The increasingly competitiveness in a globalization world demands from companies the study and use of tools, theories and concepts to provide productivity increase. Among the management tools and methods, the Operational Research has been largely diffused due to its efficiency. Especially emphasized are the Operational Research techniques of Simulation and Linear Programming that have been developed in parallel with Informatics. This research work has the main objective of comparing the application of both techniques in a manufacturing programming problem. The techniques were applied at a system responsible for manufacturing of components for the auto industry. The expected result of this study is to facilitate and explicitate the differences between the two techniques with approach to data acquisition and treatment and provide better information for a more accurate choice / Mestrado / Planejamento e Gestão Estrategica da Manufatura / Mestre em Engenharia Mecânica
29

Dynamics Of Two Link Flexible Systems : Modelling And Experiments

Nagaraj, B P 01 1900 (has links) (PDF)
No description available.
30

Job Scheduling Considering Both Mental Fatigue and Boredom

Jahandideh, Sina January 2012 (has links)
Numerous aspects of job scheduling in manufacturing systems have been the focus of several studies in the past decades. However, human factors in manufacturing systems such as workers’ mental conditions are still neglected issues and have not received adequate attentions. Job boredom and mental fatigue are both aspects of workers’ mental condition. They affect work performances by increasing sick leave duration and decreasing work productivity. On the other hand, job rotation could be an alternative strategy to cope with such human issues at work. The benefits of job rotation for both employees and firms have been widely recognized in the literature. Although some studies found job rotation as a means to reduce workers' physical work-related traumas, they did not consider the effect of variable mental conditions on workers. Despite the proven importance of boredom and mental fatigue at the workplace, they have not been a combined precise objective of any job rotation problem in current literature. The study of mental conditions proposed in this paper attempts to extend the previous works by addressing new methods and developing a feasible solution to increase manufacturing productivity. A new job scheduling program has been designed specifically which combines a new job rotation model and a job assignment method.

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