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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.
1

A new upper limit on the electron anti-neutrino rest-mass

Alizadeh, Ramin January 1989 (has links)
No description available.
2

Electron energy loss analysis for diamond and diamondlike carbon materials

Wang, Ya-Xin January 1990 (has links)
No description available.
3

Využití spotřebitelského průzkumu na vymezení relevantního trhu v železniční dopravě na trase Praha - Košice / Definition of Relevant Market in Rail Transportation on the Route Prague - Košice using consumer survey

Juhásová, Zuzana January 2016 (has links)
The aim of the thesis is to define the relevant market in railway transportation on the route Prague - Košice. In the theoretical part we describe the concept of relevant market, its use and importance for competition policy. We explain methods used for defining the relevant market and focus on the SSNIP test and its practical application, critical loss analysis. In the empirical part we conduct a consumer survey among passenger on the route Prague - Košice and use its results to compute elasticity of demand for rail transportation on the route Prague - Košice and then we perform critical loss analysis. JEL Classification C80, C81, D42, D47,K21, L41, L92 Keywords relevant market, SSNIP test, critical loss analysis, critical elasticity, critical loss Author's e-mail juhasova.zuzana@gmail.com Supervisor's e-mail vacek@fsv.cuni.cz
4

Empirical Analysis of Market Definition under Digital Convergence¡X The Merger Case of TFN Media and Kbro

Feng, Chiu-Hui 26 August 2011 (has links)
Under digital convergence, the market structure has changed which cause the traditional market definition is no longer applicable. Many industries and firms have take action of cross-industry M&A and integration. In contrast, regulations and ¡§new¡¨ market definition has not appeared which cause antitrust authorities deal with the case of the M&A under digital convergence has no quantitative tools. Our study has found that the market structure under digital convergence almost is two-sided market and multi-sided market, so we use the modified Critical Loss Analysis which Evans and Noel (2008) proposed to be the market definition tool under digital convergence. Subsequently, we use the merger case of TFN media and Kbro to do empirical analysis. By the empirical results, we find out that the relevant market of cable TV has to expand. The IPTV and online play will be the competitive product that the market structure of cable TV will be changed radically. Under digital convergence, market definition may not precisely than traditional, but it still could provide antitrust authorities an effective quantitative evidence, and with the economic theory of qualitative analysis which could make policy analysis more integrity.
5

Relative Performance Comparison and Loss Estimation of Seismically Isolated and Fixed-based Buildings Using PBEE Approach

Sayani, Prayag J 01 December 2009 (has links)
Current design codes generally use an equivalent linear approach for preliminary design of a seismic isolation system. The equivalent linear approach is based on effective parameters, rather than physical parameters of the system, and may not accurately account for the nonlinearity of the isolation system. The second chapter evaluates an alternative normalized strength characterization against the equivalent linear characterization. Following considerations for evaluation are included: (1) ability to effectively account for variations in ground motion intensity, (2) ability to effectively describe the energy dissipation capacity of the isolation system, and (3) conducive to developing design equations that can be implemented within a code framework. Although current code guidelines specify different seismic performance objectives for fixed-base and isolated buildings, the future of performance-based design will allow user-selected performance objectives, motivating the need for a consistent performance comparison of the two systems. Based on response history analysis to a suite of motions, constant ductility spectra are generated for fixed-base and isolated buildings in chapter three. Both superstructure force (base shear) and deformation demands in base-isolated buildings are lower than in fixed-base buildings responding with identical deformation ductility. To compare the relative performance of many systems or to predict the best system to achieve a given performance objective, a response index is developed and used for rapid prototyping of response as a function of system characteristics. When evaluated for a life safety performance objective, the superstructure design base shear of an isolated building is competitive with that of a fixed-base building with identical ductility, and the isolated building generally has improved response. Isolated buildings can meet a moderate ductility immediate-occupancy objective at low design strengths whereas comparable ductility fixed-base buildings fail to meet the objective. In chapter four and five, the life cycle performance of code-designed conventional and base-isolated steel frame buildings is evaluated using loss estimation methodologies. The results of hazard and structural response analysis for three-story moment resisting frame buildings are presented in this paper. Three-dimensional models for both buildings are created and seismic response is assessed for three scenario earthquakes. The response history analysis results indicate that the performance of the isolated building is superior to the conventional building in the design event. However, for the Maximum Considered Earthquake, the presence of outliers in the response data reduces confidence that the isolated building provides superior performance to its conventional counterpart. The outliers observed in the response of the isolated building are disconcerting and need careful evaluation in future studies.
6

Characterization and Failure Mode Analysis of Cascode GaN HEMT

Liu, Zhengyang 16 July 2014 (has links)
Recent emerging gallium nitride (GaN) high electron mobility transistor (HEMT) is expected to be a promising candidate for high frequency power conversion techniques. Due to the advantages of the material, the GaN HEMT has a better figure of merit (FOM) compared to the state-of-the-art silicon (Si) power metal oxide silicon field effect transistor (MOSFET), which allows the GaN HEMT to switch with faster transition and lower switching loss. By applying the GaN HEMT in a circuit design, it is possible to achieve high frequency, high efficiency, and high density power conversion at the same time. To characterize the switching performance of the GaN HEMT, an accurate behavior-level simulation model is developed in this thesis. The packaging related parasitic inductance, including both self-inductance and mutual-inductance, are extracted based on finite element analysis (FEA) methods. Then the accuracy of the simulation model is verified by a double-pulse tester, and the simulation results match well with experiment in terms of both device switching waveform and switching energy. Based on the simulation model, detailed loss breakdown and loss mechanism analysis are made. The cascode GaN HEMT has high turn-on loss due to the body diode reverse recovery of the low voltage Si MOSFET and the common source inductance (CSI) of the package; while the turn-off loss is extremely small attributing to the cascode structure. With this unique feature, the critical conduction mode (CRM) soft switching technique are applied to reduce the dominant turn on loss and increase converter efficiency significantly. The switching frequency is successfully pushed to 5MHz while maintaining high efficiency and good thermal performance. Traditional packaging method is becoming a bottle neck to fully utilize the advantages of GaN HEMT. So an investigation of the package influence on the cascode GaN HEMT is also conducted. Several critical parasitic inductors are identified, which cause high turn on loss and high parasitic ringing which may lead to device failure. To solve the issue, the stack-die package is proposed to eliminate all critical parasitic inductors, and as a result, reducing turn on loss by half and avoiding potential failure mode of the cascode GaN device effectively. Utilizing the proposed stack-die package and ZVS soft switching, the GaN HEMT high frequency, high efficiency, and high density power conversion capability can be further extended to a higher level. / Master of Science
7

ANÁLISE DE PERDAS ATRAVÉS DO CONTROLE ESTATÍSTICO DE PROCESSO: ESTUDO DE CASO EM UMA INDÚSTRIA DE MÉDIO PORTE

Gonçalves, Renato de Souza 12 March 2018 (has links)
Submitted by admin tede (tede@pucgoias.edu.br) on 2018-04-18T12:39:55Z No. of bitstreams: 1 Renato de Souza Gonçalves.pdf: 2338121 bytes, checksum: 85b8036843bc2880b84c59e7336108f9 (MD5) / Made available in DSpace on 2018-04-18T12:39:55Z (GMT). No. of bitstreams: 1 Renato de Souza Gonçalves.pdf: 2338121 bytes, checksum: 85b8036843bc2880b84c59e7336108f9 (MD5) Previous issue date: 2018-03-12 / This research aims to analyze the losses occurring in the production process of a food industry, where statistical methods were used in the milk, peanut and marmalade production line. The case study was carried out at the Doçaria Dois Irmãos, located in Anápolis state of Goiás, where all the data were obtained for the study. The Toyota Production System was used with some quality management tools for the identification and treatment of losses. The data were processed according to the Statistical Process Control, where the stability tests were performed in the production process stages, and this was done through the control charts. After stabilizing the production process with the interventions made in the industry, it was also possible to perform the process capability test, where it was verified that some process steps do not have capacity. Through the results obtained, it was also possible to measure financially the losses that were occurring in the industry, the inherent gains of the investments in the improvement actions and the time of return on the investment made. Thus, it was understood that the time of return on investments justifies the interventions in the productive process of the company in question. It was concluded, therefore, that the losses in the productive process of the industry under study, not only left the processes unstable and incapable statistically, but also was generating unnecessary production costs. By applying improvement actions in the industry, it was possible to raise important information within the production process, as well as increase the profit in the production line of the selected sweets, due to the reduction of losses in the process. / Esta pesquisa visa analisar as perdas ocorrentes no processo produtivo de uma indústria de alimentos, onde foi utilizado métodos estatísticos na linha de produção dos doces de leite, amendoim e casadinho. O estudo de caso ocorreu na Doçaria Dois Irmãos, localizada em Anápolis estado de Goiás, onde obteve-se todos os dados para a concretização do estudo. Foi utilizado o Sistema Toyota de Produção com algumas ferramentas da gestão da qualidade para identificação e tratamento das perdas. Os dados foram tratados segundo o Controle Estatístico de Processo, onde se realizou os testes de estabilidade nas etapas do processo produtivo, sendo isto realizado através das cartas de controle. Após se estabilizar o processo produtivo com as intervenções feitas na indústria, foi possível também realizar o teste de capacidade do processo, onde se verificou que algumas etapas do processo não possuem capacidade. Através dos resultados obtidos, foi ainda possível mensurar financeiramente as perdas que vinham ocorrendo na indústria, os ganhos inerentes dos investimentos nas ações de melhoria e o tempo de retorno sobre o investimento realizado. Sendo assim, entendeu-se que o tempo de retorno sobre os investimentos justifica as intervenções no processo produtivo da empresa em questão. Conclui-se, portanto, que as perdas no processo produtivo da indústria em estudo, não só deixavam os processos instáveis e incapazes estatisticamente, como também estava gerando custos de produção desnecessários. Ao se aplicar ações de melhoria na indústria, foi possível levantar importantes informações dentro do processo produtivo, bem como aumentar o lucro na linha de produção dos doces selecionados, devido à redução de perdas no processo.
8

Parameterized Seismic Reliability Assessment and Life-Cycle Analysis of Aging Highway Bridges

Ghosh, Jayadipta 16 September 2013 (has links)
The highway bridge infrastructure system within the United States is rapidly deteriorating and a significant percentage of these bridges are approaching the end of their useful service life. Deterioration mechanisms affect the load resisting capacity of critical structural components and render aging highway bridges more vulnerable to earthquakes compared to pristine structures. While past literature has traditionally neglected the simultaneous consideration of seismic and aging threats to highway bridges, a joint fragility assessment framework is needed to evaluate the impact of deterioration mechanisms on bridge vulnerability during earthquakes. This research aims to offer an efficient methodology for accurate estimation of the seismic fragility of aging highway bridges. In addition to aging, which is a predominant threat that affects lifetime seismic reliability, other stressors such as repeated seismic events or simultaneous presence of truck traffic are also incorporated in the seismic fragility analysis. The impact of deterioration mechanisms on bridge component responses are assessed for a range of exposure conditions following the nonlinear dynamic analysis of three-dimensional high-fidelity finite element aging bridge models. Subsequently, time-dependent fragility curves are developed at the bridge component and system level to assess the probability of structural damage given the earthquake intensity. In addition to highlighting the importance of accounting for deterioration mechanisms, these time-evolving fragility curves are used within an improved seismic loss estimation methodology to aid in efficient channeling of monetary resources for structural retrofit or seismic upgrade. Further, statistical learning methods are employed to derive flexible parameterized fragility models conditioned on earthquake hazard intensity, bridge design parameters, and deterioration affected structural parameters to provide significant improvements over traditional fragility models and aid in efficient estimation of aging bridge vulnerabilities. In order to facilitate bridge management decision making, a methodology is presented to demonstrate the applicability of the proposed multi-dimensional fragility models to estimate the in-situ aging bridge reliabilities with field-measurement data across a transportation network. Finally, this research proposes frameworks to offer guidance to risk analysts regarding the importance of accounting for supplementary threats stemming from multiple seismic shocks along the service life of the bridge structures and the presence of truck traffic atop the bridge deck during earthquake events.
9

Analýza ztráty integrity nádrže pomocí MKP / Structural integrity analysis of storage tank using FEM

Zahradníček, Pavel January 2014 (has links)
This diploma thesis deals with the storage tanks for petroleum products. The introductory part is devoted to the distribution of the storage tanks, associated standards and maintenance of tanks. Another part goes about the analysis of real case of a tank collapse. There was created a 3D model of the collapsed tank according to the measured values in the tank. It was created a tank shell model by drawing documentation and analysis of the results of the accident investigation using the finite element method (FEM) by program ANSYS. Calculation was performed on the buckling resistance of the structure according to ČSN EN 1993-1-6 and its comparison with the results of FEM analysis in ANSYS. The aim of the study was to find the critical condition of the structure and determination of the critical internal underpressure and overpressure. At the end there were determined measures for safe operation and settings of the valve members.
10

Diesel Engine Energy Balance Study Operating on Diesel and Biodiesel Fuels

Wallace, Scott J. 08 August 2008 (has links)
No description available.

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