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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.
331

Semiconductor Assembly Manufacturing Industry Control of Volatile Organic Compounds by Wet Scrubbing and Advanced Oxidation Technology--Case Feasibility Studies of Full-Scale Plant--

Yeh, Shu-hung 08 February 2010 (has links)
Taiwan semiconductor manufacturing industry ranks top in the world for the production and has a great contribution to Taiwan economics. However, the industry produces a significant amount of volatile organic compounds (VOC) into the air. According to EPA of Taiwan, the annual VOC emission amounts from the industry were approximately five thousand tons, a major stationary source of VOC emission. The EPA has implemented the air pollution control regulation for semiconductor industry, in which the VOC emission amount should be below <0.6 kg/hr or the removal efficiency should be >90% for each factory . The conventional control technologies for the VOC emissions was concentration using zeolite followed by thermal oxidation. However, the high boiling points of VOC is difficult to desorbed from zeolite and it required the water to wash the zeolite. This would reduce the removal efficiency of zeolite. This control processes have high operation cost and may produce byproducts required for further treatment. Advanced chemical oxidation process (AOP) recently has gained tremendous attention as an emerging control technology of VOC due to low treatment cost and few oxidation byproducts. The major oxidant of the technology is believed to be hydroxyl radicals, which can react organic compounds at very reaction rates. A majority of VOC emissions from the semiconductor industry are highly soluble and can be easily dissolved into water by scrubbing process. However, the wet scrubbing process can produce a significant amount of wastewater. The objective of this study was to investigate the feasibility of using wet scrubber and O3/H2O2/catalyst process on controlling the VOC emissions from the semiconductor manufacturing industry. A full scale of process of 1000 CMM flowrate was designed and built along with a semiconductor packaging facility. Results showed that major compounds of the VOC exhaust were iso-propanol, PGMEA, PGME and methyl ethyl keton. The inlet concentrations of THC significantly varied from 50 to 600 ppmv as methane. The AOP process can removed 90-95% of VOCs and the scrubbing water can be recycled and reused at least 95%. The capital cost of the system was NT20,000,000 with the annual operation cost of NT120,000 which was only 36-40% of it for the concentration using zeolite followed by thermal oxidation.
332

Supply Chain Models for an Assembly System with Preprocessing of Raw Materials

Rahman, Mohammad Anwar Ashek 07 February 2003 (has links)
An assembly line that procures raw materials from outside suppliers and processes the materials into finished products is considered in this research. An ordering policy is proposed for raw materials to meet the requirement of a production facility, which, in turn, must deliver finish products in a fixed quantity at a fixed time interval to the outside buyers. Two different types of raw materials, unfinished and ready-to-use, are procured for the manufacturing system. The unfinished raw materials are turned into processed raw materials after preprocessing. In the assembly line, the processed raw materials and the ready raw materials are assembled to convert into the final products. A cost model is developed to aggregate the total costs of raw materials, Work-in-process, and finished goods inventory. Based on the product design and manufacturing requirement a relationship is established between the raw materials and the finished products at different stages of production. A non-linear integer-programming model is developed to determine the optimal ordering policies for procurement of raw materials, and shipment of assembly product, which ultimately minimize the total costs of the model. Numerical examples are presented to demonstrate the solution technique. Sensitivity analysis is performed to show the effects of the parameters on the total cost model. Future research direction is suggested for further improvement of the existing results.
333

Optimal Batch Quantity Models for A Lean Production System with Rework and Scrap

Biswas, Pablo 10 January 2003 (has links)
In an imperfect manufacturing process, the defective items are produced with finished goods. Rework process is necessary to convert those defectives into finished goods. As the system is not perfect, some scrap is produced during this process of rework. In this research, inventory models for a single-stage production process are developed where defective items are produced and reworked, where scrap is produced, detected and discarded during the rework. Two policies of rework processes are considered (a) First policy: rework is done within the cycle, and (b) Second policy: rework is done after N cycles of normal production. Also, three types of scrap production and detection methods are considered for each policy, such as (i) scrap is detected before rework, (ii) scrap is detected during rework and (iii) scrap is detected after rework. Based on these inventory situations, the total cost functions for a single-stage imperfect manufacturing system are developed to find the optimum operational policy. Some numerical examples are provided to validate the model and a sensitivity analysis is carried out with respect to different parameters used to develop the model.
334

Den nya generationen KinBag : The new generation of KinBag

Svensson, Patrik, Klippberg, Lovisa, Jansson, Björn January 2007 (has links)
<p>This report summarizes a Bachelor Degree Project in Integrated Product Development,carried out during the spring semester in 2007 by three students at the Product Design Engineering programme at the University of Skövde. The project was performed as an assignment for KinBag ab, a sister subsidiary to Kinnegrip ab in Lidköping, who develop,manufacture and market the golf bag KinBag, a bag with an integrated wheel carriage system. The purpose of the project was to redesign the golf bag to attract a target group consisting of golfers aged between 20 and 40.</p><p>The layout of the project was as follows: The project began with a feasibility study where different problems were identified with the basis of a market research which eventually was summarized in a dynamic specification of requirements. The feasibility study was followed by a generation of ideas which contained everything from sketches to simple mock-ups with an intensive amount of thoughtful brainwork and information gathering in between. This led</p><p>to the development of a number of design concepts, both on an overall level and on different parts of the golf bag. Even more detailed models were created and visualized in a three dimensional environment by means of a CAD program.</p><p>The report portrays the product design process and methods utilized in the project, as well as the final result - a full-scale operational prototype of the new generation of KinBag.</p>
335

Materialflödesanalys / Material flow analysis

Hedenfeldt, Markus, Stigbäck, Johan January 2008 (has links)
<p>Denna rapport är ett resultat av den expansionsfas Söderhamn Eriksson AB i Mariannelund befinner sig i idag. De ökade kraven som ställs på tillverkningsföretag såsom SEMAB/Remill har gjort att kontakt tagits med studenter på Tekniska Högskolan i Jönköping. Den uppgift studenterna stått inför är att analysera och ge förslag, som kan förbättra materialflödet inom verksamheten i Mariannelund.</p><p>Målet med detta projekt är att förbättra och effektivisera nuvarande materialflöde hos SEMAB/Remill. För att uppnå detta mål ges förslag på en ny, fristående enhet för bearbetning av råmaterialet. Layoutförslag och vilka krav som kommer att ställas på en sådan enhet beskrivs och diskuteras. Hur verksamheten skulle kunna förbättras om situationen som råder idag behålls diskuteras vidare i rapporten.</p><p>Studier hos de två befintliga produktionsenheterna har gjorts i olika former. De metodiker som använts är nulägesbeskrivning, kartläggning av materialflöden, intervjuer och en undersökning av servicegraden in till den bearbetning (svetsning eller skärande bearbetning) som följer efter att råmaterialet kapats eller skurits.</p><p>Förseningsundersökningen som gjordes på de två produktionsenheterna gav resultatet att SEMAB hade försening på 20 % av materialet, medan Remill hade 12 % försening på sitt material. På grund av kort undersökningsperiod och något lugnare produktionstakt gav inte denna undersökning den förmodade graden av förseningar som upplevs av personer inom organisationen.</p><p>Resultatet av de analyser och förslag som kommit fram vid intervjuerna har framställts i en ny layout med placering på Remillfastigheten, samt förslag på alternativ placering. Hur företaget skulle kunna förbättra produktiviteten med förbättringsarbete är en annan del av huvudtyngdpunkten i resultatet.</p><p>I diskussionen behandlas de förslag som givits vidare. Fördelar vägs mot nackdelar och alternativ till var en ny enhet skulle kunna vara placerad ges. Ledarskapet är en viktig del vid förbättringsarbete som beskrivs och diskuteras vidare. Förslag som kommit från medarbetare, men inte bearbetats vidare reflekteras i diskussionen.</p><p>Slutsatsen av de analyser och intervjuer som gjorts är att det föreligger problem med materialhanteringen inom verksamheten. Att något måste göras för att förbättra produktiviteten förefaller därför som en självklarhet.</p><p>För att förenkla för läsaren att visuellt skapa sig en bild av hur det ser ut hos SEMAB och Remill har bilagor framställts på layouter och placeringen av de olika enheterna, dels som bilagor sist i rapporten, men även löpande i rapporten.</p>
336

Utveckling och utförande av frekvensstudie vid Rapid Granulator AB

Haugan, Martin, Randowo, Mikael January 2006 (has links)
<p>The object of this examination project is to produce a method of work sampling at Rapid Granulator AB. The aim is to perform the method at the company and evaluate if it is executable. The study is delimited to the basic construction of the 45-series in the assembly hall.</p><p>Preparations to produce the method of the work sampling resulted in definitions of activities, a form and a product tree. Several days were spent studying the assembling to learn and understand the entirety.</p><p>The work sampling result showed a large amount of no value adding time that was used in the assembling. Some of the activities could be reduced and we observed some problems during the assembly process. These problems were noted and are presented to enlighten the company, together with some suggests of changes, with the purpose to reduce the time of the assembly cycle and increase the productivity.</p><p>Conclusions of the results of the work sampling are discussed at the end.</p><p>A large amount of tables and charts, connected to preparations and results, is to be found in the appendix.</p>
337

Modelling manufacturing systems capability

Holmström, Patrik January 2006 (has links)
<p>Any way of making the manufacturing industry more efficient is always of great interest due to the contribution of manufacturing to the society. A major asset within manufacturing is information about manufacturing systems, as a base when making decisions. The most essential information within manufac-turing industry would be the manufacturing systems capability information. That information would include information about the resource, used process and produced product. Although important, manufacturing systems capability models are rare, and the information seems to be challenging to model.</p><p>The purpose of this thesis is to model manufacturing systems capability with focus on the machining industry.</p><p>In order to model manufacturing system capability, existing information standards has been used as a frame of reference. Some information standards have been evaluated on industrial cases and sometimes modified to serve a specific purpose. The information standards have been evaluated to first separately represent product, process and resource. Thereafter have the infor-mation standards been evaluated to represent all three domains together.</p><p>ISO10303-214 (AP214) has been modified and evaluated to represent any process within manufacturing. The state of the product and the state of used manufacturing system are described and connected to every relevant process step.</p><p>AP214 with ISO10303-224 (AP224) has been used together with a developed method, to describe manufacturing system capability within machining. Within the limitations of AP224 geometrical feature description, the capability of a manufacturing system can be defined and connected to a product description. Using similar feature based description for the capability and the product description, products manufacturability can be evaluated.</p><p>Also ISO14649 and ISO10303-238, both also known as STEP-NC, are treated in this thesis as enablers to describe manufacturing system capability. STEP-NC is shown to describe manufacturing systems within machining where the product, process and resource are collectively described. In order to describe capability and evaluate products manufacturability, STEP-NC has to be extended from describing/modelling one configuration of a manufacturing system to describe a set of configurations.</p>
338

Congruence between product strategy and manufacturing strategy : a framework for collaborative development

Tjärnberg, Niklas January 2006 (has links)
<p>Today’s industries face an increasing global competition. Decision makers have to deal with different kinds of uncertainty, a complex business ecosystem, a high pace of change, and an unforgiving market when less than best decisions are made. One, among many others, approach that can lead to these better decisions is to have a strategy.</p><p>The objective of this research is:</p><p>“<i>To design a model that supports the formulation of product strategy and manufacturing strategy in accordance to each other and thereby facilitate and encourage continuous communication and collaboration between product development and manufacturing system development.”</i></p><p>To help meet the objective, three chapters of frame of reference are presented; Strategy, development processes and design for X. The frame of reference together with discussions in industry (ITT Flygt) has in an iterative manner lead to a suggested model that supports the formulation of product strategy and manufacturing strategy.</p><p>Future research will improve, evaluate and validate both the usability of the model and the results from using it in practise. A method for using the model will be developed.</p><p>The research project presented in this licentiate thesis is one of seven parallel research projects with a shared objective – to develop systematic working procedures, a generic decision model and decision sub models that support the practical design of a workshop that supports the business strategy of the company.</p>
339

Service life estimations in the design of a PCM based night cooling system

Hed, Göran January 2005 (has links)
<p>The use of Phase Change Material, PCM, to change the thermal inertia of lightweight buildings is investigated in the CRAFT project C-TIDE. It is a joint project with Italian and Swedish partners, representing both industry and research. PCMs are materials where the phase change enthalpy can be used for thermal storage. The Swedish application is a night ventilation system where cold night air is used to solidify the PCM. The PCM is melted in the day with warm indoor air and thereby the indoor air is cooled. The system is intended for light weight buildings with an overproduction of heat during daytime. In the thesis, the results of experiments and numerical simulations of the application are presented. The theoretical background in order design the heat exchanger and applying the installation in thermal simulation software is presented. An extensive program is set up, in order to develop test methods and carry tests to evaluate the performance over time of the PCM. Testing procedures are set up according to ISO standards concerning service life testing. The tests are focused on the change over time of the Thermal Storage Capacity (TSC) in different temperature spans. Measurements are carried out on large samples with a water bath calorimeter. The service life estimation of a material is based on the performance of one or more critical properties over time. When the performances of these properties are below the performance requirements, the material has reached its service life. The critical properties of the PCM are evaluated by simulation of the application. The performance requirements of the material are set up according to general requirements of PCM and requirements according to building legislation. The critical properties of a PCM are the transition temperature, the melting temperature range and the TSC in the operative temperature interval. The critical property of the application is its energy efficiency.</p><p>The results of the study show that the night cooling system will lower the indoor air temperature during daytime. It also shows that the tested PCM does not have a clear phase change, but an increased specific heat in the operative temperature interval. Increasing the amount of material, used in the application, can compensate this. Finally, the tested PCM is thermally stable and the service life of the product is within the range of the design lives of the building services. It is essential to for all designers to know the performance over time of the properties of PCMs. Therefore it is desirable that standardized testing methods of PCM are established and standardized classification systems of PCMs are developed.</p>
340

En företagsmodell för modernt industriellt byggande

Gerth, Robert January 2008 (has links)
<p>Industrial housing is the strategy of the future for efficient housing. The strategy exploits the principles and work methods of production systems and is applied to the construction industry. Traditionally the construction sector considers production of one-of-a-kind products as de facto solutions. However, this strategy requires new paradigms, supporting methodologies and business models. The purpose of this thesis is to present and describe a business model that supports the strategy, which meet the project oriented market’s one-of-a-kind demands with customized multi-story houses. </p><p>Industrial manufacturing of customized houses can be accomplished by industrial strategies, such as Mass Customization. The prerequisites are that the organizational properties, mentioned in the list below, have to be integrated and adjusted to the elementary principles of industrial production and Mass Customization.</p><p>Fundamental philosophy of the Company</p><p>Organizational Structure and Management </p><p>Market and Business Process</p><p>Product ModelProduction System</p><p>Information and Communication Systems</p><p>In this thesis an industrial approach was used to identify the fundamental characteristics in industrial manufacturing and Mass Customization, and its influence of the organizational properties for industrial housing. The foundations of industrial production are a standardized product structure, standardized processes, manual and machine operations, process oriented production, and controlled material flow. Mass Customization is a strategy to achieve customized but industrial produced products with the same efficiency as mass production. It is based on standardized product models, which can be configured and flexible production systems, in which process and resources can be reconfigured in a systematic way. </p><p>On the basis of this a normative business model (The MC-House) was developed, empirical tested and validated through case studies. The truck manufacture, Scania CV AB, and the industrial housing entrepreneur, NCC Komponent AB, were investigated by interviews and company archives. The result showed that on organizational property level the business model was generic and valid for industrial manufacturing of discrete configured products. In what extent individual products could be configured and produced with a certain performance, require different designs within the organizational properties. The more individual configuration that could be managed, the more complex the executive management gets. To achieve an effective business the complexity has to be met by definition, systemizing, and integration on the corresponding organizational hierarchic level as the configuration is managed.</p><p>When considered the fundamental characteristics of construction, buildings has to be assembled there it will be used, the result also showed that the production system for industrial housing should be divided in two. One stationary manufacturing system, the factory, and one mobile assemble system at the construction site. Another condition that has to be considered is that the generic product model should be able to meet the local requirements.</p><p>Further the study indicated that the a industrial housing company is different from a traditional construction company, regarding the organizational structure, the market management, production approach, product model handling, business and project processes. Within an industrial housing company the activity is process oriented around the continuous production process. This mean that a house or a project cannot be considered as strictly unique, rather just another order which is made of standardized components, produced in the same process and with same recourses as previous and future other orders. In fact an industrial housing company has more in common with organizations of industrial manufacturing than with classical construction entrepreneurs organized for project oriented and hand craft production.</p>

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