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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

Experimental Study of Scan Based Transition Fault Testing Techniques

Jayaram, Vinay B. 19 February 2003 (has links)
The presence of delay-inducing defects is causing increasing concern in the semiconductor industry today. To test for such delay-inducing defects, scan-based transition fault testing techniques are being implemented. There exist organized techniques to generate test patterns for the transition fault model and the two popular methods being used are Broad-side delay test (Launch-from-capture) and Skewed load delay test (Launch-from-shift). Each method has its own drawbacks and many practical issues are associated with pattern generation and application. Our work focuses on the implementation and comparison of these transition fault testing techniques on multiple industrial ASIC designs. In this thesis, we present results from multiple designs and compare the two techniques with respect to test coverage, pattern volume and pattern generation time. For both methods, we discuss the effects of multiple clock domains, tester hardware considerations, false and multi-cycle paths and the implications of using a low cost tester. We then consider the implications of pattern volume on testing both stuck-at and transition faults and the effects of using transition fault patterns to test stuck-at faults. Finally, we present results from our analysis on switching activity of nets in the design, while executing transition fault patterns. / Master of Science
32

Skeva livslinjer och tickande kroppar : Tid och rum i att leva som ickebinär trans*person

Streger, Robin January 2024 (has links)
This master’s thesis investigates normative lifelines, time and space in relation to a nonbinary gender identity. My research questions focused on nonbinary aging, orientation in regards to identity and spaces, and views on maturity. I wanted to know how temporality and spatiality can be used as a theoretic framework to better understand nonbinary people’s experiences. This was achieved by interviewing seven Swedish nonbinary subjects aged 30-41 about norms regarding time and place. The results show that the nonbinary informants use gender norms to orient themselves in relation to gender identity. Aging is shown to be a gendered practice and therefore nonbinary aging and what the future will hold is made unclear for the participants. Nonbinary people seek not to be a hindrance or annoyance to the outside world and are aware that their identity often is viewed as childish, made up and illegitimate. Despite fears that they take up too much space I have shown that there is not enough space for nonbinary subjects to comfortably find a place in most rooms.
33

Contos consumados / Consummated tales

Sugimoto, Vitor de Melo 01 October 2015 (has links)
Misturando o mundano ao universo maravilhoso, esta pesquisa não só objetivou quebrar a barreira entre realidade fantasia, mas também acabou por revelar histórias profundamente humanas. / Merging the mundane and the marvellous universe, the research not only aimed to break the reality/fantasy barrier, but also ended up revealing deep human stories.
34

Essays on Gaussian Probability Laws with Stochastic Means and Variances : With Applications to Financial Economics

Eriksson, Anders January 2005 (has links)
<p>This work consists of four articles concerning Gaussian probability laws with stochastic means and variances. The first paper introduces a new way of approximating the probability distribution of a function of random variables. This is done with a Gaussian probability law with stochastic mean and variance. In the second paper an extension of the Generalized Hyperbolic class of probability distributions is presented. The third paper introduces, using a Gaussian probability law with stochastic mean and variance, a GARCH type stochastic process with skewed innovations. </p><p>In the fourth paper a Lévy process with second order stochastic volatility is presented, option pricing under such a process is also considered.</p>
35

Essays on Gaussian Probability Laws with Stochastic Means and Variances : With Applications to Financial Economics

Eriksson, Anders January 2005 (has links)
This work consists of four articles concerning Gaussian probability laws with stochastic means and variances. The first paper introduces a new way of approximating the probability distribution of a function of random variables. This is done with a Gaussian probability law with stochastic mean and variance. In the second paper an extension of the Generalized Hyperbolic class of probability distributions is presented. The third paper introduces, using a Gaussian probability law with stochastic mean and variance, a GARCH type stochastic process with skewed innovations. In the fourth paper a Lévy process with second order stochastic volatility is presented, option pricing under such a process is also considered.
36

A Comparative Study of the SIMPLE and Fractional Step Time Integration Methods for Transient Incompressible Flows

Hines, Jonathan January 2008 (has links)
Time integration methods are necessary for the solution of transient flow problems. In recent years, interest in transient flow problems has increased, leading to a need for better understanding of the costs and benefits of various time integration schemes. The present work investigates two common time integration schemes, namely the Semi-Implicit Method for Pressure-Linked Equations (SIMPLE) and the Fractional Step (FS) method. Three two-dimensional, transient, incompressible flow problems are solved using a cell centered, finite volume code. The three test cases are laminar flow in a lid-driven skewed cavity, laminar flow over a square cylinder, and turbulent flow over a square cylinder. Turbulence is modeled using wall functions and the k - ε turbulence model with the modifications suggested by Kato and Launder. Solution efficiency as measured by the effort carried out by the flow equation solver and CPU time is examined. Accuracy of the results, generated using the SIMPLE and FS time integration schemes, is analyzed through a comparison of the results with existing experimental and/or numerical solutions. Both the SIMPLE and FS algorithms are shown to be capable of solving benchmark flow problems with reasonable accuracy. The two schemes differ slightly in their prediction of flow evolution over time, especially when simulating very slowly changing flows. As the time step size decreases, the SIMPLE algorithm computational cost (CPU time) per time step remains approximately constant, while the FS method experiences a reduction in cost per time step. Also, the SIMPLE algorithm is numerically stable for time steps approaching infinity, while the FS scheme suffers from numerical instability if the time step size is too large. As a result, the SIMPLE algorithm is recommended to be used for transient simulations with large time steps or steady state problems while the FS scheme is better suited for small time step solutions, although both time-stepping schemes are found to be most efficient when their time steps are at their maximum stable value.
37

A Comparative Study of the SIMPLE and Fractional Step Time Integration Methods for Transient Incompressible Flows

Hines, Jonathan January 2008 (has links)
Time integration methods are necessary for the solution of transient flow problems. In recent years, interest in transient flow problems has increased, leading to a need for better understanding of the costs and benefits of various time integration schemes. The present work investigates two common time integration schemes, namely the Semi-Implicit Method for Pressure-Linked Equations (SIMPLE) and the Fractional Step (FS) method. Three two-dimensional, transient, incompressible flow problems are solved using a cell centered, finite volume code. The three test cases are laminar flow in a lid-driven skewed cavity, laminar flow over a square cylinder, and turbulent flow over a square cylinder. Turbulence is modeled using wall functions and the k - ε turbulence model with the modifications suggested by Kato and Launder. Solution efficiency as measured by the effort carried out by the flow equation solver and CPU time is examined. Accuracy of the results, generated using the SIMPLE and FS time integration schemes, is analyzed through a comparison of the results with existing experimental and/or numerical solutions. Both the SIMPLE and FS algorithms are shown to be capable of solving benchmark flow problems with reasonable accuracy. The two schemes differ slightly in their prediction of flow evolution over time, especially when simulating very slowly changing flows. As the time step size decreases, the SIMPLE algorithm computational cost (CPU time) per time step remains approximately constant, while the FS method experiences a reduction in cost per time step. Also, the SIMPLE algorithm is numerically stable for time steps approaching infinity, while the FS scheme suffers from numerical instability if the time step size is too large. As a result, the SIMPLE algorithm is recommended to be used for transient simulations with large time steps or steady state problems while the FS scheme is better suited for small time step solutions, although both time-stepping schemes are found to be most efficient when their time steps are at their maximum stable value.
38

偏態預測:台灣加權指數報酬率之研究 / Predicting conditional skewness:Evidence from the return distribution of the Taiwan Stock Exchange Value-Weighted Index

李家昇 Unknown Date (has links)
此論文研究有什麼因子會影響台灣股票加權指數報酬率之偏態係數。過去的文獻顯示,交易量和報酬率為可能的因子。實證的結果確實發現,交易量和報酬率顯著地影響偏態係數。 / This study examines the determinants for conditional skewness of the return distribution of the Taiwan Stock Exchange Value-Weighted Index. Important driving factors that affect conditional skewness, based on the theory literature, include trading volumes and returns. To capture the skewness in the data, the family of time series model we consider focuses on the specifications of higher-order moments than mean and volatility that conventional models look at. With the specifications, we are able to test whether the factors, volumes and returns, can influence conditional skewnees of the return distribution. Our results suggest the significance of the factors using data from the Taiwan Stock Exchange Value-Weighted Index.
39

Bayesian Inference on Mixed-effects Models with Skewed Distributions for HIV longitudinal Data

Chen, Ren 01 January 2012 (has links)
Statistical models have greatly improved our understanding of the pathogenesis of HIV-1 infection and guided for the treatment of AIDS patients and evaluation of antiretroviral (ARV) therapies. Although various statistical modeling and analysis methods have been applied for estimating the parameters of HIV dynamics via mixed-effects models, a common assumption of distribution is normal for random errors and random-effects. This assumption may lack the robustness against departures from normality so may lead misleading or biased inference. Moreover, some covariates such as CD4 cell count may be often measured with substantial errors. Bivariate clustered (correlated) data are also commonly encountered in HIV dynamic studies, in which the data set particularly exhibits skewness and heavy tails. In the literature, there has been considerable interest in, via tangible computation methods, comparing different proposed models related to HIV dynamics, accommodating skewness (in univariate) and covariate measurement errors, or considering skewness in multivariate outcomes observed in longitudinal studies. However, there have been limited studies that address these issues simultaneously. One way to incorporate skewness is to use a more general distribution family that can provide flexibility in distributional assumptions of random-effects and model random errors to produce robust parameter estimates. In this research, we developed Bayesian hierarchical models in which the skewness was incorporated by using skew-elliptical (SE) distribution and all of the inferences were carried out through Bayesian approach via Markov chain Monte Carlo (MCMC). Two real data set from HIV/AIDS clinical trial were used to illustrate the proposed models and methods. This dissertation explored three topics. First, with an SE distribution assumption, we compared models with different time-varying viral decay rate functions. The effect of skewness on the model fitting was also evaluated. The associations between the estimated decay rates based on the best fitted model and clinical related variables such as baseline HIV viral load, CD4 cell count and longterm response status were also evaluated. Second, by jointly modeling via a Bayesian approach, we simultaneously addressed the issues of outcome with skewness and a covariate process with measurement errors. We also investigated how estimated parameters were changed under linear, nonlinear and semiparametric mixed-effects models. Third, in order to accommodate individual clustering within subjects as well as the correlation between bivariate measurements such as CD4 and CD8 cell count measured during the ARV therapies, bivariate linear mixed-effects models with skewed distributions were investigated. Extended underlying normality assumption with SE distribution assumption was proposed. The impacts of different distributions in SE family on the model fit were also evaluated and compared. Real data sets from AIDS clinical trial studies were used to illustrate the proposed methodologies based on the three topics and compare various potential models with different distribution specifications. The results may be important for HIV/AIDS studies in providing guidance to better understand the virologic responses to antiretroviral treatment. Although this research is motivated by HIV/AIDS studies, the basic concepts of the methods developed here can have generally broader applications in other fields as long as the relevant technical specifications are met. In addition, the proposed methods can be easily implemented by using the publicly available WinBUGS package, and this makes our approach quite accessible to practicing statisticians in the fields.
40

Contos consumados / Consummated tales

Vitor de Melo Sugimoto 01 October 2015 (has links)
Misturando o mundano ao universo maravilhoso, esta pesquisa não só objetivou quebrar a barreira entre realidade fantasia, mas também acabou por revelar histórias profundamente humanas. / Merging the mundane and the marvellous universe, the research not only aimed to break the reality/fantasy barrier, but also ended up revealing deep human stories.

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