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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.
31

LED封裝產業發展分析-以台灣一LED封裝廠為例 / LED packages industrial analysis -a taiwan LED package as the model

劉偉凱, Liu, Ken Unknown Date (has links)
LED is one of the competitive businesses in the optical industry of Taiwan. Taiwan also has the most complete structure of LED industry from the chips (upstream) to the LED packages (downstream). Especial for the LED packages, from very beginning’s red, green, yellow and amber colors to blue and white colors, the LED companies in Taiwan have all participated more than 40 years and stand the very important role in the global LED industry. With the last 10 years, Due to the government in China also see the huge potential of LED business, so they invested the LED industry especial for the chips and packages started from the year 2000 as the important country development plan. However, with this 16 years’ over expansion in China, the global LED industry already became the cost driven industry for most of applications like lighting, TFT-LCD and consumer applications. How to find the next potential applications for LED package industry in Taiwan and have the difference than the companies in China will be the future growth opportunity of the LED business in Taiwan.
32

Optimalizace obalového hospodářství ve firmě Škoda Auto, a. s. / Optimalization of packaging management in Škoda Auto

Matějovská, Jana January 2009 (has links)
This diploma thesis deals with the transport packages in Škoda Auto Inc. and generally with questions of package and waste management. The aim of this work is to analyze the transport packages in corporation Škoda Auto and on the basis of this analysis specify, if the optimization of package management is possible and at the same time suggest recommendation to realization of this optimization. The first part of thesis is focused on basic term, legislation and definition of possibilities of firms in environmental protection. Second part is the case study in Škoda Auto Inc., which deals with the relations between corporation and environment, analysis of the transport packages and their optimization. Recommendations for internal changes in corporation are formulated in this part too. In conclusion you can find the resolution, if the optimization is possible and how could be achieved.
33

Proposta de método de controle integrado entre produção e qualidade com mensuração de perdas por making-do e pacotes informais

Fireman, Marcus Costa Tenorio January 2012 (has links)
O controle de perdas tem sido apontado como uma das principais estratégias para melhoria do desempenho e para redução de custos de sistemas de produção. Entretanto, apesar de sua importância, este é um tema pouco abordado na literatura sobre gestão da construção, principalmente no que se refere a sistemas de controle da produção. Alguns estudos recentes chamaram a atenção para a existência de uma perda típica do setor, denominada de making-do, a qual pode ser definida como a redução de desempenho do sistema produtivo devido à execução de atividades em condições subótimas. Este tipo de perda ainda tem sido apontada como uma das causas fundamentais de problemas da qualidade, e de outras perdas, tais como retrabalho e trabalho em progresso. Falhas na análise de restrições realizadas no planejamento de médio prazo têm sido apontadas como a principal razão para o surgimento de perdas por making-do, pois na ausência dos requisitos necessários para execução das atividades normalmente as equipes realizam improvisações, que podem afetar o desempenho da produção. O presente trabalho propõe um método de controle integrado produção e qualidade que permita mensurar perdas por making-do e também a ocorrência de pacotes de trabalho informais. Este método está dividido em três módulos: (a) identificação de perdas por making-do; (b) identificação de pacotes informais; e (c) controle integrado produção e qualidade. O desenvolvimento da pesquisa foi dividido nas seguintes etapas: (a) compreensão do problema; (b) estruturação do método; (c) consolidação do método; (d) avaliação dos resultados e proposição do método final. Como principais contribuições do trabalho, além do próprio método proposto, o estudo propõe uma conceitualização de perdas por making-do, retrabalho e falta de terminalidade. Ainda, os resultados demonstram a existência de uma forte relação entre as perdas por making-do, a execução de pacotes informais e o aumento do trabalho em progresso. / Waste control has been pointed out as one of the key strategies for improving the performance and reducing costs of production systems. However, despite its importance, this is a topic poorly discussed in the construction management literature, especially in relation to production control systems. Some recent studies have called the attention for a type of waste that is typical of the construction sector, named making-do, which can be defined as a loss in performance due to the execution of activities in sub-optimal conditions. It has been suggested that this type of waste is one of the root causes of quality failures, and also of other types of waste, such as rework and work in progress. Failures in constraint analysis at the medium term planning level have been pointed out a major cause of makingdo waste, as the crews tend to improvise when faced with the lack of prerequisites for the execution of tasks, which may affect the production performance. This research work proposes a method for integrated production and quality control, which enables the measurement making-do waste and also the occurrence of informal work packages This method is divided into three modules: (a) identification of making-do waste; (b) identification of informal work packages; and (c) integrated and production and quality control. The development of this research work was divided into the following stages: (a) understanding the problem; (b) structuring the method; (c) consolidating the method; (d) evaluation of results and proposition of the final version of the method. As main contributions, besides the integrated control method, this investigation proposes a conceptualization for three categories of waste: making-do, rework, and unfinished work. Moreover, the results indicate that there is a strong relationship making-do waste, the execution of informal packages and the increase of work in progress.
34

Analýza nabídky cestovních kanceláří / The analysis of supply of travel agencies

Hrušková, Dana January 2011 (has links)
The diploma thesis analyses supply of three major and three small regional Czech travel agencies regarding Croatia in terms of its width (number of offered accomodation facilities in particular sea resorts)and its compelexity (offer of packages for more demanding customers, sightseeing tours etc.) The thesis also contains general introduction of Croatia as one of the most popular summer destinations for Czech tourists as well as description and explanation of basic terms connected to tourism theory and functioning of travel agencies in general.
35

Evaluation de la fiabilité de boîtiers électroniques QFN à base de nanocomposites LCP/SiO2 fonctionnalisées / Evaluation of the reliability of electronic packages QFN-based on nanocomposites LCP / SiO2 functionalized

Chenniki, Walide 15 July 2015 (has links)
Dans le cadre du développement de boîtiers à cavités pour composants électroniques, les polymères à cristaux liquides (LCP) offrent des propriétés intéressantes capables de rivaliser avec les matériaux en céramique : une faible perméabilité aux gaz, une résistance à haute température, une stabilité thermique et une faible constante diélectrique (3,1 à 1 MHz et 2,8 à 10 GHz). Cette nouvelle génération de thermoplastiques permettra de concurrencer les boîtiers métalliques et céramiques à cavité plus coûteux et de s’ouvrir à de nouvelles applications comme l’imagerie médicale par exemple.Dans ce contexte, nous proposons une technique de fonctionnalisation de nanoparticules minérales (via procédé Sol-Gel) et leur incorporation à la matrice polymère afin de modifier ces propriétés mécaniques (Module de Young et CTE) et son anisotropie. La fiabilité de boîtiers est évaluée à l’aide de simulations thermomécaniques. Le but est d’établir un lien entre les propriétés mécaniques des composites à base de LCP et la durée de vie des boîtiers électroniques. Le développement de capots optiques pour ces boîtiers est aussi étudié afin d’obtenir une filtration dans la proche infrarouge pour des applications dans le secteur de la téléphonie mobile. / As part of the development of cavities packages for electronic components, Liquid Crystal Polymers (LCP) offer interesting properties and compete with ceramic materials: low gas permeability, high temperature resistance, thermal stability and low dielectric constant (3.1 to 2.8 for 1 MHz and 10 GHz). This new generation of thermoplastic will compete with classic packages more expensive and open to new applications such as medical imaging for example.In this context, we propose an original approach of mineral nanoparticles functionalization (via sol-gel process) and their incorporation into the polymer matrix to modify the mechanical properties (Young's modulus and CTE) and the anisotropy. Packaging reliability is assessed using thermomechanical simulations. The goal is to establish a link between the mechanical properties of composites based on LCP and the characteristic lifetime of the package. The development of optical covers for these packages is also study to obtain a filter in the near infrared for applications in the mobile phone sector.
36

A comparative analysis of lectures versus interactive computer-assisted learning packages for the teaching and learning of anatomy by tertiary students.

Lee, Harry B. January 1996 (has links)
The primary aim of this study was to validate interactive computer-assisted learning packages (ICALP) in a self operated computer controlled educational resource (SOCCER) to undergraduate (UG) physiotherapy students of anatomy. The development of ICALP, Test and FeedBack items for SOCCER are described, as well as the mechanism of delivery with continuous positive reinforcement to randomly selected students. To meet this requirement, a computer managed learning environment (CMLE) was established to affirm the value of ICALP and SOCCER materials to replace traditional lectures in anatomy. Quantitative data is given to verify this hypothesis during the education of UG physiotherapy students of anatomy. Throughout 1992, the UG population was randomly divided into Lecture and ICALP groups, with mutual exclusion of each to the other, for ten areas of study. These results were validated by re-application to the succeeding UG population in 1993. The secondary aim of this study was in two-parts. Firstly, to verify that ICALP materials can be applied to transfer 2-D cognitive anatomical information in a self-paced format of autonomous learning. Secondly, to investigate a premise that previously acquired 2-D anatomical information may be transferred into a 3-D psycho-motor skill. Ample data is given to verify the first hypothesis, with sufficient evidence to support the second. The subsidiary aim of this study compared the educational and administrative cost-effectiveness of ICALP and SOCCER with traditional lectures used in anatomy. Evidence is given to demonstrate that the time saved in lectures can be replaced by a lecture-seminar approach to problem-based learning to empower UG2 students to achieve at a level beyond that which would normally be expected. Sufficient data is provided to affirm the cost-benefits of ICALP and SOCCER to academic staff, individual students, and ++ / administrators. The untested belief held by schools of anatomy that high ranking pre-entrants in English, English Literature, and Human Biology, are more likely to transpose 2-D anatomical information into a 3-D skill than high ranking pre-entrants in Mathematics, Chemistry and Physics was also investigated. Scrutiny of these data could not determine any discriminatory differences of ability to succeed in UG anatomy by either of these two categories.
37

Trust the process: stakeholder management using a transparent, evidence-based policy approach

Auburn, Stephen Donald, sauburn@optusnet.com.au January 2005 (has links)
In Australia, the development and implementation of National Training Packages has been a major tool in the drive to reform of the vocational education and training system. The main aim of the reform is to establish a national vocational and education system within a federal political system and to make vocational educations and training providers more responsive to the needs of industry, by industry specifying its skill needs through the mechanism of national Training Packages. The background to this workplace project, the Review of the Community Services Training Package, and this study, is established by a review of policy and literature in relation to national training reform issues and stakeholder management within a public policy context. This review established some principles of good practice in relation to stakeholder management. The industry context of the workplace project is discussed. The workplace project is then unpacked in some detail with specific reference to stakeholder management strategies and issues and some specific stakeholder groups. This exegesis goes on to explore stakeholder behaviour in this particular workplace project in its historical context of the introduction of Training Packages to the vocational education and training system. It explores the perspectives of teachers and industry on the implementation of Training Packages and in particular the gap between educational technologies and industry expectations of standards of work performance. The exegesis concludes with some suggestions of opportunities for enhanced workplace practice in stakeholder management and for further research. It also suggests a job of work for industry and teachers to develop new communities of practice around Training Packages as a means of bringing together their sometimes divergent interests.
38

Visualizing, Assessing and Re-Modularizing Object-Oriented Architectural Elements

Abdeen, Hani 24 November 2009 (has links) (PDF)
To cope with the complexity of large object-oriented software systems, developers organize classes into subsystems using the concepts of module or package. Such modular structure helps software systems to evolve when facing new requirements. The organization of classes into packages and/or subsystems represents the software modularization. the software modularization usually follows interrelationships between classes. Ideally, packages should to be loosely coupled and cohesive to a certain extent. However, Studies show that as software evolves to meet requirements and environment changes, the software modularization gradually drifts and looses quality. As a consequence, the software modularization must be maintained. It is thus important to understand, to assess and to optimize the organization of packages and their relationships. Our claim is that the maintenance of large and complex software modularizations needs approaches that help in: (1) understanding package shapes and relationships; (2) assessing the quality of a modularization, as well as the quality of a single package within a given modularization; (3) optimizing the quality of an existing modulariza- tion. In this thesis, we concentrate on three research fields: software visualizations, metrics and algorithms. At first, we define two visualizations that help maintainers: (1) to understand packages structure, usage and relationships; (2) to spot patterns; and (3) to identify misplaced classes and structural anomalies. In addition to visual- izations, we define a suite of metrics that help in assessing the package design quality (i.e., package cohesion and coupling). We also define metrics that assess the quality of a collection of inter-dependent packages from different view points, such as the degree of package coupling and cycles. Finally, we define a search-based algorithm that automatically reduces package coupling and cycles only by moving classes over existing packages. Our optimization approach takes explicitly into account the origi- nal class organization and package structure. It also allows maintainers to control the optimization process by specifying: (1) the maximal number of classes that may change their packages; (2) the classes that are candidate for moving and the classes that should not; (3) the packages that are candidate for restructuring and the packages that should not; and (4) the maximal number of classes that a given package can entail. The approaches presented in this thesis have been applied to real large object- oriented software systems. The results we obtained demonstrate the usefulness of our visualizations and metrics; and the effectiveness of our optimization algorithm.
39

Optimization of Heat Sinks with Flow Bypass Using Entropy Generation Minimization

Hossain, Md Rakib January 2006 (has links)
Forced air cooling of electronic packages is enhanced through the use of extended surfaces or heat sinks that reduce boundary resistance allowing heat generating devices to operate at lower temperatures, thereby improving reliability. Unfortunately, the clearance zones or bypass regions surrounding the heat sink, channel some of the cooling air mass away from the heat sink, making it difficult to accurately estimate thermal performance. The design of an "optimized" heat sink requires a complete knowledge of all thermal resistances between the heat source and the ambient air, therefore, it is imperative that the boundary resistance is properly characterized, since it is typically the controlling resistance in the path. Existing models are difficult to incorporate into optimization routines because they do not provide a means of predicting flow bypass based on information at hand, such as heat sink geometry or approach velocity. <br /><br /> A procedure is presented that allows the simultaneous optimization of heat sink design parameters based on a minimization of the entropy generation associated with thermal resistance and fluid pressure drop. All relevant design parameters such as geometric parameters of a heat sink, source and bypass configurations, heat dissipation, material properties and flow conditions can be simultaneously optimized to characterize a heat sink that minimizes entropy generation and in turn results in a minimum operating temperature of an electronic component. <br /><br /> An analytical model for predicting air flow and pressure drop across the heat sink is developed by applying conservation of mass and momentum over the bypass regions and in the flow channels established between the fins of the heat sink. The model is applicable for the entire laminar flow range and any type of bypass (side, top or side and top both) or fully shrouded configurations. During the development of the model, the flow was assumed to be steady, laminar, developing flow. The model is also correlated to a simple equation within 8% confidence level for an easy implementation into the entropy generation minimization procedure. The influence of all the resistances to heat transfer associated with a heat sink are studied, and an order of magnitude analysis is carried out to include only the influential resistances in the thermal resistance model. Spreading and material resistances due to the geometry of the base plate, conduction and convection resistances associated with the fins of the heat sink and convection resistance of the wetted surfaces of the base plate are considered for the development of a thermal resistance model. The thermal resistance and pressure drop model are shown to be in good agreement with the experimental data over a wide range of flow conditions, heat sink geometries, bypass configurations and power levels, typical of many applications found in microelectronics and related fields. Data published in the open literature are also used to show the flexibility of the models to simulate a variety of applications. <br /><br /> The proposed thermal resistance and pressure drop model are successfully used in the entropy generation minimization procedure to design a heat sink with bypass for optimum dimensions and performance. A sensitivity analysis is also carried out to check the influence of bypass configurations, power levels, heat sink materials and the coverage ratio on the optimum dimensions and performance of a heat sink and it is found that any change in these parameters results in a change in the optimized heat sink dimensions and flow conditions associated with the application for optimal heat sink performance.
40

Optimization of Heat Sinks with Flow Bypass Using Entropy Generation Minimization

Hossain, Md Rakib January 2006 (has links)
Forced air cooling of electronic packages is enhanced through the use of extended surfaces or heat sinks that reduce boundary resistance allowing heat generating devices to operate at lower temperatures, thereby improving reliability. Unfortunately, the clearance zones or bypass regions surrounding the heat sink, channel some of the cooling air mass away from the heat sink, making it difficult to accurately estimate thermal performance. The design of an "optimized" heat sink requires a complete knowledge of all thermal resistances between the heat source and the ambient air, therefore, it is imperative that the boundary resistance is properly characterized, since it is typically the controlling resistance in the path. Existing models are difficult to incorporate into optimization routines because they do not provide a means of predicting flow bypass based on information at hand, such as heat sink geometry or approach velocity. <br /><br /> A procedure is presented that allows the simultaneous optimization of heat sink design parameters based on a minimization of the entropy generation associated with thermal resistance and fluid pressure drop. All relevant design parameters such as geometric parameters of a heat sink, source and bypass configurations, heat dissipation, material properties and flow conditions can be simultaneously optimized to characterize a heat sink that minimizes entropy generation and in turn results in a minimum operating temperature of an electronic component. <br /><br /> An analytical model for predicting air flow and pressure drop across the heat sink is developed by applying conservation of mass and momentum over the bypass regions and in the flow channels established between the fins of the heat sink. The model is applicable for the entire laminar flow range and any type of bypass (side, top or side and top both) or fully shrouded configurations. During the development of the model, the flow was assumed to be steady, laminar, developing flow. The model is also correlated to a simple equation within 8% confidence level for an easy implementation into the entropy generation minimization procedure. The influence of all the resistances to heat transfer associated with a heat sink are studied, and an order of magnitude analysis is carried out to include only the influential resistances in the thermal resistance model. Spreading and material resistances due to the geometry of the base plate, conduction and convection resistances associated with the fins of the heat sink and convection resistance of the wetted surfaces of the base plate are considered for the development of a thermal resistance model. The thermal resistance and pressure drop model are shown to be in good agreement with the experimental data over a wide range of flow conditions, heat sink geometries, bypass configurations and power levels, typical of many applications found in microelectronics and related fields. Data published in the open literature are also used to show the flexibility of the models to simulate a variety of applications. <br /><br /> The proposed thermal resistance and pressure drop model are successfully used in the entropy generation minimization procedure to design a heat sink with bypass for optimum dimensions and performance. A sensitivity analysis is also carried out to check the influence of bypass configurations, power levels, heat sink materials and the coverage ratio on the optimum dimensions and performance of a heat sink and it is found that any change in these parameters results in a change in the optimized heat sink dimensions and flow conditions associated with the application for optimal heat sink performance.

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