Orientador: Flávio Vasconcelos da Silva / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-21T21:00:26Z (GMT). No. of bitstreams: 1 Rodrigues_Sergio_M.pdf: 4024499 bytes, checksum: 621b50dee12f09a22c121b01b7c3340b (MD5) Previous issue date: 2012 / Resumo: Neste trabalho foi utilizada uma série histórica de dados reais de danos sofridos na rede de distribuição de gás natural da concessionária Comgás, em sua área de concessão no estado de São Paulo abrangendo 177 municípios das regiões metropolitanas de São Paulo, Campinas, Baixada Santista e Vale do Paraíba. Com a análise desses dados foi observado que a ocorrência de danos na rede subterrânea de distribuição de gás natural é composta por harmônicas de diferentes frequências e amplitudes. Através da aplicação da transformada de Fourier a série histórica de dados de danos, identificou-se a presença de quatro harmônicas e seus respectivos períodos e magnitudes. De posse desses coeficientes de Fourier aplicou-se a eles a série de Fourier e construiu-se um modelo matemático que representou a função dano com um intervalo de confiança de 94% tornando assim possível prever sua intensidade no domínio do tempo / Abstract: This study used a real third party excavation damages time series data on a natural gas distribution network that belongs to Comgás in your concession area, Brazil, São Paulo state with 177 cities included in metropolitan areas as São Paulo, Campinas, Santos and Vale do Paraiba, demonstrates that this occurrence is droved by harmonic or cycled forces with different frequencies am magnitudes. Due to the application of Fourier transform at the historical damages time series data there was an identification of four harmonic forces and your periods and magnitudes. With this Fourier coefficients identified was applied to a Fourier series to model the third party damage function in time domain. This model gets a 94% of confidential interval and becomes able to prevent damages or time periods with more incidences of damages / Mestrado / Sistemas de Processos Quimicos e Informatica / Mestre em Engenharia Química

Orientador: Jose Roberto de França Arruda / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-07-31T18:15:00Z (GMT). No. of bitstreams: 1 Rossetto_GustavoDalben_M.pdf: 4484828 bytes, checksum: b149e9723524115d4c39c2ea81d0c5bc (MD5) Previous issue date: 2001 / Resumo: Neste trabalho uma geometria simples (cavidade retangular) é usada para o estudo da metodologia aplicada na análise modal acústica. Modelos analítico e numérico são desenvolvidos para a comparação com os resultados experimentais. Três tipos de dispositivos de excitação do sistema acústico foram construídos. Um baseado num pistão conectado a um shaker, e outros dois usando um alto-falante do tipo driver. O primeiro atuador usando o driver é similar ao modelo desenvolvido por um projeto europeu, onde um tubo flexível com uma terminação instrumentada com um microfone é usado para a condução da excitação acústica. O segundo atuador baseado no uso do driver também usa um tubo flexível, mas este é instrumentado com dois microfones em sua terminação. O comportamento destes dois últimos atuadores em termos de aceleração de volume (essencial para a análise modal acústica experimental) e de potência ativa (necessária para Análise Estatística de Energia Experimental) sendo injetados no meio são investigados. A análise modal experimental da cavidade retangular é realizada e um método que utiliza a transformada de Fourier espacial multidimensional do campo de pressão medido é proposto para-a construção do campo de deslocamento de partícula para a visualização do modo acústico / Abstract: In the present work, a simple geometry (rectangular shallow cavity) is used to investigate the acoustic modal analysis methodology. Analytical and numerical models are developed for the comparison with the experimental results. Three types of excitation devices were constructed. One based on a shaker-driven piston and the other two using a driver loudspeaker. The first actuator based on a driver loudspeaker is similar to a model developed by an EEC project, where a flexible tube with a socket, instrumented with one microphone, at its termination is used to conduct the sound excitation. The second actuator based on a driver loudspeaker alse uses a flexible tube, but it is instrumented with two microphones in its socket instead of one. The behavior of these last two actuators in terms of volume acceleration (essential in the acoustic modal analysis) and active power (necessary for the Experimental Statistical Energy Analysis) being injected into the medium are investigated. The experimental modal analysis of the rectangular cavity is performed and a method using multi-dimensional spatial Fourier transforms of the array of pressure measurements is proposed for the construction of the partic1e displacement field for acoustic mode shape visualization / Mestrado / Mecanica dos Sólidos e Projeto Mecanico / Mestre em Engenharia Mecânica

The goal of this thesis is to apply the theory of multilinear weighted Fourier estimates to nonlinear dispersive equations in order to tackle problems in regularity, well-posedness, and pointwise convergence of solutions. Dispersion of waves is a ubiquitous physical phenomenon that arises, among others, from problems in shallow-water propagation, nonlinear optics, quantum mechanics, and plasma physics. A natural tool for understanding the related physics is to study waves/signals simultaneously from both physical and spectral perspectives. Specifically, we will treat nonlinearities as multilinear operator perturbations, which (by the method of spacetime Fourier transforms), exhibit smoothing properties in norms defined to reflect the dispersive natures of the solutions. Our model equation is the quantum Zakharov system, which can be viewed as a variation on the cubic nonlinear Schrödinger equation (NLS). We investigate the model in various contexts (adiabatic limits, nonlinear Schrödinger limits, semi-classical limits). We additionally study a variation of Carleson's Fourier convergence problem in the context of pointwise convergence of the full Schrödinger operator with non-zero potential.

Sexual dimorphism of the distal humerus has been used for the development of morphometric sex estimation methods in human identification. In particular, visual assessment of the olecranon fossa, trochlear shape, and medial epicondyle angle are variably successful in differentiating females and males in African, Asian, and European groups. However, the influence of other factors on the distal humerus has yet to be fully explored. This study utilizes elliptical Fourier analysis (EFA) to examine the shape of these three features for evidence of sexual dimorphism and the effects of age-at-death, stature, and humeral measurements in 261 modern Thai individuals (f=116; m=145), 20-97 years of age. Left humeri were measured, photographed, traced, and analyzed in SHAPE v. 1.3 for EFA. Chi-square, ANOVA, and principal component results indicate sexual dimorphism in the olecranon fossa and trochlear extension shapes, both of which are correlated with epicondylar breadth. Trochlear extension was also found to be correlated with minimum midshaft diameter, vertical head diameter, and stature. The medial epicondyle was not correlated with any of the other factors examined, and age was not correlated with any of the shapes. High rates of intra- and interobserver error were found in the tracings of the three features. While future research should assess methods that better capture the medial epicondyle and improve reliability, features of the distal humerus are sexually dimorphic and somewhat affected by stature and/or body size.

This report documents the process of designing a laboratory exercise in Fourier analysis at Vetenskapens Hus (House of Science) in Stockholm. The lab is designed for high school students studying science or technical education. It focuses on the physical understanding and mathematical description of sound, in particular music. A model of such a lab is presented in this work; containing a review of the mathematical theory, summary of educational research in the field, descriptions of the design process and of the investigative work that led to the final result. The designed material for the lab includes developed computer programs, visit leader tutorial and description for teachers.

A digital program has been developed to Fourier analyse the data obtained in experiments to study the de Haas-van Alphen effect. A physical account of the origin of this effect is given and the problem of analysing the data is explained. An account is given of the development of the program together with a consideration of the mathematical properties of the Fourier transform. General questions concerning the resolving power and accuracy of this method of analysis are discussed. The program was tested using artificial synthetic data of known analytic form and later applied to the analysis of data from a single crystal of mercury. / Thesis / Master of Science (MSc)

<p> The present study has two objectives. The first is to apply a reliable and valid technique of eeg frequency analysis to the measurement of the human alpha rhythm. The second objective is to find a chemical agent which will alter an individual's dominant occipital frequency 2 Hz from its resting frequency. The techniques used are: dextrose ingestion, fasting, oxygen inhalation, hyperventilation, carbon dioxide inhalation, diamox, alcohol, librium and dexedrine. The treatments which did produce a 2 Hz shift in dominant frequency also produced new peaks in other parts of the frequency spectrum. Evidence is presented which suggests that the alpha rhythm can be made to fluctuate over a very narrow frequency range (approx. 1 Hz ).</p> / Thesis / Master of Arts (MA)

Laser speckle photography is an experimental technique which provides a non-contract means for direct measurement of in-plane displacements of objects subjected to different loading conditions. It requires a camera system to record two images of the object that are illuminated with laser light on a high resolution film. The double-exposure film (specklegram) is a permanent record of the displacement information of the object. Point-by-point analysis of the specklegram will yield the displacement data, but requires considerable time to complete the data reduction. An automated data analysis system is developed and described in this report. He-Ne laser and computer-controlled translation stages holding the specklegram represent the first part of the system. A linear diode sensor is used to digitize the generated fringe pattern. Finally, a microcomputer and a spectrum analyzer are used to perform the analysis. The system has been successfully applied to the computation of displacements of a cantilever beam. Comparisons to theoretical results indicate that the system is indeed a viable one and may be sued for a more complex displacement analysis.

Sapphire fiber based temperature sensors are exceptional in their ability to operate at temperatures above 1000C and as high as 1800C. Sapphire fiber technology is emerging and the fiber is available commercially. Sapphire fiber has a high loss, is highly multi-mode and does not have a solid cladding, but it is nonetheless very useful in high temperature applications. Of the available interferometer configurations, Fabry-Perot interferometers are distinguished in their high accuracy and great isolation from sources of error. In this thesis, improvements are reported to an existing design to enhance its reliability and to reduce possible modes of failure. The existing high temperature sensor design has shown a lot of potential in the past by continuously measuring the temperature in a coal gasifier for 7 months, but its true potential has not yet been realized. The goal of this work and the work of many others is to extend the working life and reliability of high-temperature optical sapphire temperature sensors in harsh environments by exploring a solid cladding for sapphire fiber, improved fringe visibility sapphire wafers and a new sensor design. This project is supported by the National Energy and Technology Laboratory of the Department of Energy. / Master of Science

In this dissertation we provide a comprehensive theory for the formation of a moire pattern in a sampled halftone image. We explore techniques for restoring a sampled halftone image with a moire pattern and techniques for preventing a moire pattern when a halftone picture is scanned. Specifically, we study the frequency, phase, and spatial geometry of a moire pattern. We observe and explain the half period phase reversal phenomenon that a moire pattern may exhibit. As a case study, we examine the moire patterns generated by a commercial scanner. We propose three restoration methods, including a notch filtering method, a simulation method, and a relaxation method. We also describe a moire prevention method, the partial inverse Fourier transform method. Finally, we propose a research agenda for further investigation. / Ph. D.