The semestral project deals with characteristics and theory of CDMA, OFDM and VSFOFCDM systems. As comparison and evaluation of these systems as transmission channel is being done for Matlab.

This master's thesis describes the design and the implementation of a step-down converter with variable output voltage for laboratory purposes. In the introduction the basic functions of switching power supplies are shown, flyback, forward and push-pull converters are described, followed by some integrated circuits for power management of converters. The second chapter discusses in detail the design of requested switched power supply, including the calculation of the electronic parts and design of the storage inductor. Following are described some observations of building this power supply, including the output characteristics. In conclusion, the obtained results are assessed, including proposals to improve whole design.

This paper describes the methods used mainly in the filtration of audio signals -- noise reduction. It realizes segmentation with variable lenght of segment, constant overlap add and segmentation with variable lenght of segment and overlap add. These methods are then compared with comon methods of segmentation in dependance of the lenght of segment and used window function by the thresholding method. For this purpose it uses the database of audio records. In the first part it desrcibes the technique of audio signal processing with comon method of segmentation. According to this method it continues in design of signal processing by variable segmentation method, in which it is needed to modify the shape of window function, which influences and attributes are explained in next chapter. In practical part it describes the implemented methods in MATLAB programming language with each steps of testing. It continues with chart of enclosed files and the evaluation of the results of hearing tests.

Shallow water equations are widely used to model water flows in the field of hydrodynamics and civil engineering. They are complex, and except for some simplified cases, no analytical solution exists for them. Therefore, the partial differential equations of the shallow water system have been the subject of various numerical analyses and studies in past decades. In this study, we construct a stable and robust finite volume scheme for the shallow water equations over quadtree grids. Quadtree grids are two-dimensional semi-structured Cartesian grids that have different applications in several fields of engineering, such as computational fluid dynamics. Quadtree grids refine or coarsen where it is required in the computational domain, which gives the advantage of reducing the computational cost in some problems. Numerical schemes on quadtree grids have different properties. An accurate and robust numerical scheme is able to provide a balance between the flux and source terms, preserve the positivity of the water height and water surface, and is capable of regenerating the grid with respect to different conditions of the problem and computed solution. The proposed scheme uses a piecewise constant approximation and employs a high-order Runge-Kutta method to be able to make the solution high-order in space and time. Hence, in this thesis, we develop an adaptive well-balanced positivity preserving scheme for the shallow water system over quadtree grids utilizing different techniques. We demonstrate the formulations of the proposed scheme over one of the different configurations of quadtree cells. Six numerical benchmark tests confirm the ability of the scheme to accurately solve the problems and to capture small perturbations. Furthermore, we extend the proposed scheme to the coupled variable density shallow water flows and establish an extended method where we focus on eliminating nonphysical oscillations, as well as well-balanced, positivity preserving, and adaptivity properties of the scheme. Four different numerical benchmark tests show that the proposed extension of the scheme is accurate, stable, and robust.

Master of Science

Este libro es una guía teórico-práctica que permite al estudiante de administración y carreras afines entender los conceptos sobre los que se fundamenta cada tema y aplicarlos a sus análisis administrativos. Para ello, además de una breve explicación teórica, en cada tema se presentan ejemplos resueltos y luego por resolver para fijar el aprendizaje. Finalmente, se cierra cada unidad con una serie de ejercicios aplicados. Esta obra es producto de la experiencia obtenida a lo largo de varios años en la coordinación y dictado de los cursos de la Universidad Peruana de Ciencias Aplicadas como Nivelación de Matemáticas, Lógica Matemática y, principalmente, Matemática Básica para Administradores. Asimismo, está complementado con los aportes y problemas propuestos por la mayoría de los profesores de estos cursos. Se trata entonces de una publicación útil y práctica para administradores, estudiantes y profesores.

Este libro es una guía teórico-práctica que permite al estudiante de administración y carreras afines entender los conceptos sobre los que se fundamenta cada tema y aplicarlos a sus análisis administrativos. Para ello, además de una breve explicación teórica, en cada tema se presentan ejemplos resueltos y luego por resolver para fijar el aprendizaje. Finalmente, se cierra cada unidad con una serie de ejercicios aplicados. Esta obra es producto de la experiencia obtenida a lo largo de varios años en la coordinación y dictado de los cursos de la Universidad Peruana de Ciencias Aplicadas como Nivelación de Matemáticas, Lógica Matemática y, principalmente, Matemática Básica para Administradores. Asimismo, está complementado con los aportes y problemas propuestos por la mayoría de los profesores de estos cursos. Se trata entonces de una publicación útil y práctica para administradores, estudiantes y profesores.

MSc (Mathematics) / Department of Mathematics

This doctoral dissertation proposal is comprised of three separate chapters, all of which uses the nationally representative uniform survey Health and Retirement Survey (HRS) to examine the relationship between health, insurance, health care and health outcomes. Below, the brief introduction for each section is provided:  Chapter I: Medicare Part D and Patients' Well-being  Chapter II: Parent's Health Insurance and Informal Care  Chapter III: Job Insecurity and Health (with Dr. Ayyagari) In chapter I, I explore how Medicare Part D (MD) affects the well-being of the severely sick patients both in the short- and in the long- term. I employ difference-in-difference (DD) alongside the instrumental variable (IV) model. The estimated results imply MD significantly improves mental health and increases regular drug utilization for the elderly. However, it neither systematically improves out-of-pocket payment (OOP) nor improves mortality across all waves. This suggests that MD provides an efficient mechanism to improve mental health and drug utilization, but might not necessarily enhance survival rate and financial burden for vulnerable patients. Chapter II investigates the relationship between informal care provided by the children and the take-up of health insurance by the near-elderly and elderly parents, and how the correlation is influenced by parent’s Activities of Daily Living (ADLs) and Instrumental Activities of vii Daily Living (IADLs). The results indicate that when the endogeneity is controlled for, in-formal care systematically crowds out the take-up of private long-term care (LTC) insurance whereas “crowds in” the take-up of the total plan including supplement insurance plans (TSP). Nevertheless, the degree of both crowding-out and “crowding-in” effect is reduced when the severity of ADLs/IADLs disability level grows. Our study reflects (a) the strong demand for TSP and more additional health coverage within household budget line (b) and the potential gap between healthcare demands by the parents and the informal care provided by the children and the potential gap between the healthcare demands by the parents and the formal care covered by the insurance. Our estimates are robust to alternative measures of informal care. The final chapter III examines the causal effect of subjective job insecurity on health, using pooled ordinary least squares (OLS), fixed-effects (FE) and instrumental variable (IV) specifications. The estimate implies that the negative impact of job insecurity is more pronounced for certain outcomes such as mental health and the emergence of new health conditions. Job insecurity provides a powerful prediction on subsequent job displacement and real income loss. Sub-population such as low-employability/better-educated individuals or males responds more to job insecurity than their counterparts.

Rainfall-runoff modeling in the United States has made extensive use of the Soil Conservation Service (SCS) curve number method for computing infiltration losses from rainfall. Even though the method is well established and may be applied to a wide range of environments, it often results in highly erroneous runoff estimates for shallow water table environments. Flat topography, wetlands, and fine sands are characteristics that make places like Florida very different from the environments where the SCS method was originally developed. The SCS method arose from experiments with soils that are dominated by infiltration excess (Hortonian mechanism), where runoff occurs after rainfall intensity exceeds the infiltration capacity of the soil. In contrast, Florida is likely dominated by saturation excess runoff (Dunne mechanism), where the soil storage capacity between a shallow water table and the ground surface is filled, and all remaining rainfall becomes runoff. The sandy soils of Florida have very high infiltration capacities, and thus infiltration excess is less likely than saturation excess. As a consequence of the saturation-excess mechanism, wetlands expand in the wet season as the soil moisture storage around the perimeter is filled. A modified form of the SCS method is proposed with the objective that it is more suitable than the current method in flatly sloped, humid environments. Initial conditions, such as the pre-storm soil moisture profile and depth to water table, are critical when predicting runoff in these areas. Air encapsulation is addressed because its presence causes the soil storage capacity to be filled significantly faster than in its absence. Equations are presented that provide an estimate of the average depth to water table and average soil storage capacity in a catchment. Two Florida catchments and one runoff test bed were selected for testing the new methodology. The runoff test bed demonstrated the saturation-excess mechanism while the catchments provided larger-scale testing of the method. Though more data is needed to fully assess the performance of the method, the approach offers a more plausible mechanism for runoff estimation in shallow water table environments with sandy soils.