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No / Rotation is a well-known operation on lists. We define its two-dimensional analogue and discuss its implementation in Prolog using difference lists. An application to the iterative solution of a system of linear equations by the Gauss¿Seidel method is given.

Column-supported, geosynthetic-reinforced embankments provide effective geotechnical foundations for applications in areas of weak subgrade soils. The system consists of a soil bridging layer with one or more embedded layers of geosynthetic reinforcement supported by driven or deep mixed columnar piles. The geosynthetic promotes load transfer within the bridging layer to the columns, allowing for larger column spacings and varied alignments. This technique is generally used when differential settlements of the embankment or adjacent structures are a concern and to minimize construction time. Recent increase in the popularity of this composite system has generated the need to further investigate its behavior and soil-structure interaction. Current models of geosynthetics are oversimplified and do not represent the true three-dimensional nature of the material. Such simplifications include treating the geosynthetic as a one-dimensional cable as well as neglecting stress concentrations and pile orientations. In this thesis, a complete three-dimensional analysis of the geosynthetic is performed. The geosynthetic was modeled as a thin flexible plate in a single square unit cell of the embankment. The principle of minimum potential energy was then applied, utilizing central finite difference equations. Energy components from vertical loading, soil and column support, as well as bending and membrane stiffness of the geosynthetic are considered. Three pile orentation types were implemented: square piles, circular piles, and square piles rotated 45° to the edges of the unit cell. Each of the pile orientations was analyzed using two distinct parameter sets that are investigated in previously published and ongoing research. Vertical and in-plane deflections, stress resultants, and strains were determined and compared to other geosynthetic models and design guides. Results of each parameter set and pile orientation were also compared to provide design recommendations for geosynthetic-reinforced column-supported embankments. / Master of Science

A state space model is developed for a class of integro-partial differential equations of hyperbolic type which arise in viscoelasticity. An approximation scheme is developed based on a spline approximation in the spatial variable and an averaging approximation in the de1ay variable. Techniques from linear semigroup theory are used to discuss the well-posedness of the state space model and the convergence properties of the approximation scheme. We give numerical results for a sample problem to illustrate some properties of the approximation scheme. / Ph. D.

Finite-difference models have been used for nearly 40 years to solve electromagnetic problems of heterogeneous nature. Further, these techniques are well known for being computationally expensive, as well as subject to various numerical artifacts. However, little is yet understood about the errors arising in the simulation of wideband sources with the finitedifference time-domain (FDTD) method. Within this context, the focus of this thesis is on two different problems. On the one hand, the speed and accuracy of current FDTD implementations is analysed and increased. On the other hand, the distortion of numerical pulses is characterised and mitigation techniques proposed. In addition, recent developments in general-purpose computing on graphics processing units (GPGPU) have unveiled new methods for the efficient implementation of FDTD algorithms. Therefore, this thesis proposes specific GPU-based guidelines for the implementation of the standard FDTD. Then, metaheuristics are used for the calibration of a FDTD-based narrowband simulator. Regarding the simulation of wideband sources, this thesis uses first Lagrange multipliers to characterise the extrema of the numerical group velocity. Then, the spread of numerical Gaussian pulses is characterised analytically in terms of the FDTD grid parameters. The usefulness of the proposed solutions to the previously described problems is illustrated in this thesis using coverage and wideband predictions in large-scale scenarios. In particular, the indoor-to-outdoor radio channel in residential areas is studied. Furthermore, coverage and wideband measurements have also been used to validate the predictions. As a result of all the above, this thesis introduces first an efficient and accurate FDTD simulator. Then, it characterises analytically the propagation of numerical pulses. Finally, the narrowband and wideband indoorto-outdoor channels are modeled using the developed techniques.

Approved for public release, distribution is unlimited / This thesis examines the magnitude of the deterrence effect associated with the implementation of the "zero tolerance" policy in the U.S. military in the early 1980s. The estimation of the deterrence effect is based on the estimation of linear probability models (LPM). A difference-in-difference estimator is obtained by comparing pre- and post-policy differences in drug use rates in the military and civilian sectors. The thesis uses data on drug participation drawn from the National Household Survey of Drug Abuse and the DoD Worldwide Health Survey. The study investigates the deterrence effect for the military as a whole, for each branch, for various age groups, and two different measures of drug participation. The results show that a significant deterrence effect appears to have been associated with the implementation of the "zero tolerance" and drug testing policy, especially for the past year drug participation rates. Additionally, there is evidence that individuals above 25 years old who are more educated and married have smaller drug participation rates than the rest of the population. / Lieutenant Commander, Hellenic Navy

This thesis analyzes the trade liberalization implemented in the form of FTA between Peru and USA in 2009 and its effect on the welfare of different clusters of individuals. In the ambient of economy with high income inequities it evaluates the liberalization separately for different income-level samples. The research is based on the comparison of groups of individuals occupied in sectors that were already liberalized by other market opening tools before 2009 and groups recently affected by the FTA. The analysis is than accomplished on the household survey panel data covering the period between 2007 and 2010. The findings suggest the trade liberalization positively affected not only the wealthier population but also the poor, both from the category of individuals working in sectors producing for domestic consumption. The positive effect on export-oriented producers hasn't been approved.

The economic value of sport has long been an interesting subject to study. Proponents arguing there is big monetary return for a region hosting a professional sports team. However, majority of studies done on the subject point in the same direction where it seems economic return are negligible. Researchers even argue there is rather an alternative cost where money could be better spent on other social structure such as education and health care. The value of sport creates both direct and indirect effect. In this essay I will look at whether there could be any indirect spillover effects from hosting a hockey team in the highest league. Due to its simplicity, a difference-in-difference (DiD) method will be used on municipalities hosting a hockey team. This when looking at Gross Regional Product (GRP), unemployment rate and population growth to municipalities without a hockey team. The results of this study are ambiguous and hard to interpret when sign on coefficient differ between variables and municipalities. However, there seem to be a correlation between lower unemployment rate and population growth and an increase in GRP when a team is qualifying to SHL. It cannot be determined whether this depend on economic growth or success of their professional sports team.

This paper studies five mergers in the European wireless telecommunication industry and analyzes their impact on prices and capital expenditures of both merging carriers and their rivals. We find substantial heterogeneity in the relationship between increases in concentration and carriers' prices. The specifics of each merger case clearly matter. Moreover, we find a positive correlation between the price and the investment effect; when the prices after a merger increase (decrease), the investments increase (decrease) too. Thus, we document a trade-off between static and dynamic efficiency of mergers.

Neste trabalho é apresentada uma etnografia sobre jovens freqüentadores da Rua Augusta e adjacências na cidade de São Paulo. São analisadas as negociações desses jovens em relação à freqüência de lugares comuns por jovens de estilos diferentes. A maneira como as diferenças são transformadas em desigualdade através do uso de marcadores sociais da diferença é analisada tendo como base uma bibliografia sobre sexualidade, papel de gênero, heteronormatividade e estilo. Será apresentado o campo onde foi feita a pesquisa e contingências da observação participante em um ambiente de flerte. Em seguida são comentadas as perspectivas teóricas utilizadas na análise dos dados obtidos em campo. Também será apresentada a descrição das pessoas que freqüentavam os locais descritos durante o decorrer da observação e por fim são feitas considerações finais sobre os tópicos presentes nos capítulos anteriores. / This work presents an ethnography on young frequenters of Augusta street and the nearby locations in the city of São Paulo. It analyzes the negotiations these youngsters carry in relation to the presence of different styles in that area. The manner in which difference is transformed into inequality through the use of social markers of difference is analyzed based on a bibliography on sexuality, heteronormativity and style. The fieldwork is presented as well as the contingencies of doing participating observation in an environment of flirting. Then there are comments on the theoretical perspectives used to analyze the obtained data. It also presents a depiction of the people present in the field during the time of the research and lastly the final considerations on the data from the other chapters are presented.