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

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.

<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>

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.

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.

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.

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.

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.

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.

The aim of this study is to examine if social media has a negative impact on how womenperceive their own body image. The study was conducted by a quantitative survey usingquestionnaires to examine the various factors that affect the perceived body image. Such ashow women socially compare themselves with others or how satisfied they are with theirbody depending on how much time they spend on social media. We will also investigate ifwomen’s perceived body image is consistent with the their actual body based upon theirBMI. The sample for the study consisted of 159 women who are members of a specificFacebook group. The material was analyzed with support from Festinger’s theory of socialcomparison and Cooley’s glass-self theory among others. The results show that high use ofsocial media affects women’s satisfaction with how they look negatively compared withthose who use social media to a low degree. It also shows that women who spend a lot oftime on social media tend to compare themselves with other more widely and tend to beunhappier with their body. On the other hand, we could not see any correlation between theuse of social media and women’s perception of their actual body. / Syftet med studien är att undersöka om sociala medier har en negativ påverkan på hurkvinnor uppfattar sin egen kroppsbild. Studien genomfördes av en kvantitativ undersökningmed hjälp av enkäter för att undersöka de olika faktorerna som påverkar den uppfattadekroppsbilden. Såsom hur kvinnor jämför sig med andra eller hur nöjda de är med sin kroppberoende på hur mycket tid de spenderar på sociala medier. Vi kommer likaså undersöka omkvinnors uppfattade kroppsbild överensstämmer med deras faktiska kropp baserat på derasBMI. Urvalet för studien bestod av 159 kvinnor som är medlemmar i facebookgruppen Pinkroom. Materialet analyserades med bland annat stöd av Festingers teori om social jämförelseoch Cooleys teori om spegeljaget. Resultaten visar att vid hög användning av sociala medierpåverkas kvinnornas tillfredsställelse med kroppen i jämförelse med dem som användersociala medier i liten utsträckning. Det visar också att kvinnor som spenderar mycket tid påsociala medier tenderar att jämföra sig med andra i större utsträckning och att dem tenderaratt vara mer missnöjda med sin kropp.