Submitted by Livia Mello (liviacmello@yahoo.com.br) on 2016-09-23T20:38:51Z No. of bitstreams: 1 TeseWNN.pdf: 1247691 bytes, checksum: 63f743255181169a9bb4ca1dfd2312c2 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-26T20:35:27Z (GMT) No. of bitstreams: 1 TeseWNN.pdf: 1247691 bytes, checksum: 63f743255181169a9bb4ca1dfd2312c2 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-26T20:35:33Z (GMT) No. of bitstreams: 1 TeseWNN.pdf: 1247691 bytes, checksum: 63f743255181169a9bb4ca1dfd2312c2 (MD5) / Made available in DSpace on 2016-09-26T20:35:40Z (GMT). No. of bitstreams: 1 TeseWNN.pdf: 1247691 bytes, checksum: 63f743255181169a9bb4ca1dfd2312c2 (MD5) Previous issue date: 2016-02-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / In this thesis we study the asymptotic properties for the solution of the Cauchy problem for the Klein-Gordon equation with non-effective time-dependent potential. The main goal was define a suitable energy related to the Cauchy problem and derive decay estimates for such energy. Strichartz’ estimates and results of scattering and modified scattering was established. The C m theory and the stabilization condition was applied to treat the case where the coefficient of the potential term has very fast oscillations. Moreover, we consider a semi-linear wave model scale-invariant time- dependent with mass and dissipation, in this step we used linear estimates related with the semi-linear model to prove global existence (in time) of energy solutions for small data and we show a blow-up result for a suitable choice of the coefficients. / Nesta tese estudamos as propriedades assintóticas para a solução do problema de Cauchy para a equação de Klein-Gordon com potencial não efetivo dependente do tempo. O principal objetivo foi definir uma energia adequada relacionada ao problema de Cauchy e derivar estimativas para tal energia. Estimativas de Strichartz e resultados de scatering e scatering modificados também foram estabelecidos. A teoria C m e a condição de estabilização foram aplicados para tratar o caso em que o coeficiente da massa oscila muito rápido. Além disso, consideramos um mod- elo de onda semi-linear scale-invariante com massa e dissipação dependentes do tempo, nesta etapa usamos as estimativas lineares de tal modelo para provar ex- istência global (no tempo) de solução de energia para dados iniciais suficientemente pequenos e demonstramos um resultado de blow-up para uma escolha adequada dos coeficientes.

Made available in DSpace on 2015-05-14T12:14:13Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 607405 bytes, checksum: 901b07535dd697c3ac45d2bdfef30f70 (MD5) Previous issue date: 2014-08-08 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this thesis, we study the generalized harmonic oscillator with frequency dependent mass and time and subjected to a friction force whose speed depends on the time, of classical and quantum points of view. Obtained the solutions of the classical equation of motion of this system for some special cases, we derive an equation of motion that describes three systems. Then, with the help of quadratic invariant operators the light of the method of dynamical invariants we find the exact solutions of the Schrodinger equation for this system. We derive the geometric, dynamic and Berry for this system non-stationary phases and we evaluate this phases for three special cases. After this, we construct coherent states for this quantized system and employ them to investigate some properties quantum properties such as quantum uctuations of the coordinate and momentum as well as the product of the uncertainties. We then use a linear invariant operator light of the method of dynamical invariants in the intention of finding exact Schrodinger equation for the damped harmonic oscillator for forced time-dependent solutions. As described in our contribution we built solutions in the form of Gaussian wave packets as well as calculate the quantum uctuations of the coordinates and time, as well as the correlations between them. Finally, we show that the width of the uctuations and correlations of the Gaussian packet does not depend on the external force / Na presente tese, estudamos o oscilador harmônico generalizado com massa e frequência dependentes do tempo e submetido a uma força de fricção linear na velocidade cujo coeficiente de fricção depende do tempo, do ponto de vista clássico e quântico. Obtivemos as soluções da equação de movimento clássica deste sistema para alguns casos particulares e derivamos uma equação de movimento que descreve simultaneamente três sistemas diferentes. Em seguida, com a ajuda dos operadores invariantes quadráticos e à luz do método de invariantes dinâmicos encontramos as soluções exatas da equação de Schrodinger para este sistema. Também derivamos as fases geométrica, dinâmica e de Berry para este sistema não-estacionário e as avaliamos para três casos especiais. Ainda construímos estados coerentes para este sistema quantizado e os empregamos para investigar algumas propriedades quânticas tais como utuações quânticas da coordenada e momento bem como do produto das incertezas. Em seguida, utilizamos um operador invariante linear e usamos o método de invariantes dinâmicos para encontrar soluções exatas da equação de Schrodinger para um oscilador harmônico amortecido e forçado dependente do tempo. Com as soluções desta equação, construímos soluções na forma de pacotes de onda Gaussianos assim como calculamos as utuações quânticas das coordenadas e momentos, bem como as correlações entre ambos. Finalmente, mostramos que a largura das utuações e correlações do pacote Gaussiano não dependem da força externa.

Made available in DSpace on 2015-05-14T12:14:20Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 650048 bytes, checksum: 434d6fa42298be2011c48aa4e06477c3 (MD5) Previous issue date: 2008-06-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this thesis, we use linear invariants and the method of dynamical invariants to obtain exact solutions of the Schr¨odinger equation for the generalized time-dependent forced harmonic oscillator in terms of the solutions of a second order ordinary differential equation that describes the amplitude of the classical unforced damped oscillator. In addition, we construct gaussian wave packet solutions and calculate the fluctuations in coordinate and momentum as well as the quantum correlations between them. It is shown that the width of the Gaussian packet, fluctuations and correlations do not depend on the external force. As a particular case, we consider the forced Caldirola-Kanai oscillator. In addition, we use the Coulomb gauge, linear invariants and the method of dynamical invariants in the framework of the Schr¨odinger equation to obtain a quantum description of the light propagation through a homogeneous conducting linear media with no charge density. We obtain exact wave functions for this problem in terms of solutions of a second order ordinary differential equation which describes the amplitude of the classical damped harmonic oscillator. Furthermore, we construct gaussian wave packet solutions and calculate the fluctuations in coordinate and momentum as well as the quantum correlations for every mode of the quantized electromagnetic field. We also use quadratic invariants together method of dynamical invariants to study the light propagation in a conducting media. We obtain exact solutions of the time-dependent Schr¨odinger equation for this case and construct coherent and squeezed states for the quantized electromagnetic waves. Yet, we evaluate the quantum fluctuations in coordinate and momentum as well as the uncertainty product for every mode of the electromagnetic field. Finally, we use quadratic invariants and the dynamical invariant method for obtain exact wavefunctions of the Schr¨odinger equation for a particle trapped by oscillating fields. / Na presente tese, usamos operadores invariantes lineares à luz do método de invariantes dinâmicos para encontrar as soluções exatas da equação de Schrödinger para um oscilador harmônico forçado generalizado dependente do tempo em termos das soluções de uma equação diferencial de segunda ordem que descreve a amplitude de um oscilador harmônico amortecido não-for¸cado. Construimos as soluções do tipo pacotes de ondas gaussianos e calculamos as flutuações quânticas das coordenadas e momentos, bem como da correlação entre ambos. Como destaque, mostramos que a largura das flutuações e as correlações do pacote gaussiano não dependem da força externa. Como caso particular, aplicamos nosso formalismo ao conhecido oscilador forçado de Caldirola-Kanai. Depois, fazemos uma descrição quântica da propagação da luz num meio condutor, homogêneo, linear e com densidade de carga nula, usando o modelo de oscilador harmônico dependente de tempo numa abordagem fenomenológica usando o gauge de Coulomb, invariantes lineares e o método do invariante dinâmico. Obtemos as funções de onda exatas para este problema em termos de soluções de uma equação diferencial de segunda ordem que descreve a amplitude do oscilador amortecido clássico. Além disso, construimos soluções do tipo pacotes de onda gaussianos e calculamos as flutuações e as correlações quânticas para cada modo do campo eletromagnético quantizado. Em seguida, estendemos nossa investiga ção utilizando também um operador invariante quadrático. Encontramos as funções de onda exatas para a equação de Schrödinger para a luz num meio condutor com frequência dependente do tempo. Concluímos a presente tese abordando o problema de encontrar funções de onda (soluções da equação de Schrodinger) exatas, com dependência temporal, para uma partícula aprisionada por campos oscilantes.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Nesta dissertaÃÃo foi estudado o problema de processar consultas kNN em redes de rodovias considerando o histÃrico das condiÃÃes de trÃfego, em particular o caso onde a velocidade dos objetos mÃveis depende do tempo. Dado que um usuÃrio està em uma dada localizaÃÃo e em um determinado instante de tempo, a consulta retorna os k pontos de interesse (por exemplo, postos de gasolina) que podem ser alcanÃados em uma quantidade de tempo mÃnima considerando condiÃÃes histÃricas de trÃfego. SoluÃÃes anteriores para consultas kNN e outras consultas comuns em redes de rodovia estÃticas nÃo funcionam quando o custo das arestas (tempo de viagem) à dependente do tempo. A construÃÃo de estratÃgias e algoritmos eficientes e corretos, e mÃtodos de armazenamento e acesso para o processamento destas consultas à um desafio desde que algumas das propriedades de grafos comumente supostas em estratÃgias para redes estÃticas nÃo se mantÃm para redes dependentes do tempo. O mÃtodo proposto aplica uma busca A∗ à medida que vai, de maneira incremental, explorando a rede. O objetivo do mÃtodo à reduzir o percentual da rede avaliado na busca. Para dar suporte à execuÃÃo do algoritmo, foi tambÃm proposto um mÃtodo para armazenamento e acesso para redes dependentes do tempo. A construÃÃo e a corretude do algoritmo sÃo discutidas e sÃo apresentados resultados experimentais com dados reais e sintÃticos que mostram a eficiÃncia da soluÃÃo. / In this dissertation we study the problem of processing k-nearest neighbours (kNN)queries in road networks considering the history of traffic conditions, in particular the case where the speed of moving objects is time-dependent. For instance, given that the user is at a given location at a certain time, the query returns the k points of interest (e.g., gas stations) that can be reached in the minimum amount of time. Previous solutions to answer kNN queries and others common queries in road networks do not work when the moving speed in each road is not constant. Building efficient and correct approaches and algorithms and storage and access schemes for processing these queries is a challenge because graph properties considered in static networks do not hold in the time dependent case. Our approach uses the well-known A∗ search algorithm by applying incremental network expansion and pruning unpromising vertices. The goal is reduce the percentage of network assessed in the search. To support the algorithm execution, we propose a storage and access method for time-dependent networks. We discuss the design and correctness of our algorithm and present experimental results that show the efficiency and effectiveness of our solution.

A utilização de concreto projetado como suporte de túneis é uma prática amplamente difundida no mundo inteiro. Este tipo material possui a característica de começar a agir estruturalmente desde pequenas idades. Apesar disso, os correntes processos de dimensionamento de suportes negligenciam o desenvolvimento de suas propriedades com o tempo, em acoplamento aos efeitos tridimensionais da região onde se localiza a frente de escavação. O presente trabalho tem a finalidade de relatar os procedimentos utilizados na análise da influência de alguns parâmetros da interação maciço - suporte, sobre os esforços solicitantes e os deslocamentos radiais finais do suporte de um túnel, tanto para o caso de concreto projetado, com suas propriedades dependentes do tempo, quanto para materiais com propriedades constantes. São elaboradas soluções adimensionais para o problema da quantificação de esforços solicitantes no suporte e de deslocamentos radiais na interface entre maciço e suporte. Além disso, é proposta uma forma de se determinar, através destas soluções adimensionais, coeficientes de alívio de tensões que auxiliam em simulações bidimensionais de escavações subterrâneas. / The utilization of shotcrete as tunnel support is a widely diffused practice in the whole world. This kind of material has the feature of beginning to act structurally since early ages. Nevertheless, the current processes of support design neglect the development of its properties after some time in connection to the 3D effects of the region where the face of the tunnel is located. The present work relates the procedures adopted in analyzing the influence of some ground-support interaction parameters on the support internal forces and interface radial displacements of a tunnel, not only when shotcrete is used, with its time-dependent properties, but for materials with constant properties as well. Dimensionless solutions are developed for the support thrust and radial displacement quantification problem. Moreover, through this dimensionless solution, a way of quantifying stress relief factors, which are intermediate steps in 2D simulations of underground excavations, is proposed.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Neste trabalho apresentamos soluÃÃes clÃssicas e quÃnticas de osciladores harmÃnicos acoplados dependentes do tempo. Nesses sistemas as massas, frequÃncias e o parÃmetro de acoplamento sÃo funÃÃes do tempo. Quatro sistemas sÃo investigados. Para obter as soluÃÃes clÃssicas usamos uma transformaÃÃo de coordenada e momento juntamente com uma transformaÃÃo canÃnica para escrever o Hamiltoniano original como a soma de dois Hamiltonianos de osciladores harmÃnicos desacoplados dependentes do tempo com frequÃncias modificadas dependentes do tempo e massas unitÃrias. Encontramos soluÃÃes analÃticas para a posiÃÃo e a velocidade para cada oscilador de todos os sistemas. Para obter as soluÃÃes quÃnticas exatas usamos uma transformaÃÃo unitÃria e o mÃtodo invariante de Lewis e Riesenfeld. As funÃÃes de onda sÃo escritas em termos de uma quantidade escalar a qual à soluÃÃo da equaÃÃo de Milne-Pinney. Para cada sistema resolvemos a respectiva equaÃÃo de Milne-Pinney e discutimos como as flutuaÃÃes quÃnticas e o produto de incerteza evoluem no tempo. / In this work we present the classical and quantum solutions of time-dependent coupled harmonic oscillators. In these systems the masses, frequencies and coupling parameter (k) are functions of time. Four systems are investigated. To obtain the classical solutions we use a coordinate and momentum transformations along with a canonical transformation to write the original Hamiltonian as the sum of two Hamiltonians of uncoupled harmonic oscillators with modified time-dependent frequencies and unitary masses. We find the analytical expression for position and velocity of each oscillator of the systems. To obtain the exact quantum solutions we use a unitary transformation and the Lewis and Riesenfeld invariant method. The wave functions obtained are written in terms of a c-number quantity () which is solution of the Milne-Pinney equation. For each system we solve the respective Milne-Pinney equation and discuss how the quantum fluctuations and the uncertainty product evolve with time.

Cette thèse est consacrée à l’étude de problèmes inverses associés à des équations aux dérivées partielles hyperboliques et de type Schrödinger.La première partie de la thèse est consacrée à l’étude de problèmes inverses pour l’équation des ondes. Il s’agit d’examiner les propriétés de stabilité et d’unicité dans l’identification de certains coefficients apparaissant dans l’équation des ondes, à partir de différents types d’observation.La deuxième partie de cette thèse, traite du problème de l’identification du champ magnétique et du potentiel électrique apparaissant dans l’équation du Schrödinger. Nous prouvons que ces coefficients peuvent être déterminés de façon stable dans tout le domaine, à partir de données de type Neumann. La dérivation de ces résultats est basée sur la construction d’un ensemble de solutions de type optique géométrique, adaptées au système étudié. Il existe une méthode alternative pour l’analyse de ce type de problèmes inverses, celle de Bukhgeim-Klibanov, qui utilise une estimation de Carleman spécifique à l’opérateur con-sidéré. Elle nous a permis de montrer qu’il est possible de récupérer de façon stable et simultanée, la partie spatiale des potentiels électrique et magnétique de l’équation de Schrödinger magnétique, à partir d’un nombre fini de mesures partielles de la solution. / This thesis is devoted to the study of inverse problems associated to hyperbolic and Schrödinger equations. The first part of the thesis is devoted to the study of inverse problemsfor the wave equation. The aim is to examine the stability andthe uniqueness issues in the identification of certain coefficients appearing in the wave equation from different types of observation. The second part of this thesis deals with the problem of the identification of a magnetic field and an electric potential appearing in the Schrödinger equation. We prove that these coefficients can be stably determined throughout the domain, using Neumann data. The derivation of these results is based on the construction of a set of geometric optics solutions adapted to the system studied. There is an alternative method for the analysis of this type of inverse problem, which is due to Bukhgeim-Klibanov, and which uses a Carleman estimate. We show that it is possible to stably and simultaneously recover the spatial part of the electrical and magnetic potentialsappearing in the magnetic Schrödinger equation, from a finite number of measurements.

For children with intractable seizures, surgical removal of epileptic foci, if identifiable and feasible, can be an effective way to reduce or eliminate seizures. The success of this type of surgery strongly hinges upon the ability to identify and demarcate those epileptic foci. The ultimate goal of this research project is to develop an effective technology for detection of unique in vivo pathophysiological characteristics of epileptic cortex and, subsequently, to use this technology to guide epilepsy surgery intraoperatively. In this PhD dissertation the feasibility of using optical spectroscopy to identify unique in vivo pathophysiological characteristics of epileptic cortex was evaluated and proven using the data collected from children undergoing epilepsy surgery. In this first in vivo human study, static diffuse reflectance and fluorescence spectra were measured from the epileptic cortex, defined by intraoperative ECoG, and its surrounding tissue from pediatric patients undergoing epilepsy surgery. When feasible, biopsy samples were taken from the investigated sites for the subsequent histological analysis. Using the histological data as the gold standard, spectral data was analyzed with statistical tools. The results of the analysis show that static diffuse reflectance spectroscopy and its combination with static fluorescence spectroscopy can be used to effectively differentiate between epileptic cortex with histopathological abnormalities and normal cortex in vivo with a high degree of accuracy. To maximize the efficiency of optical spectroscopy in detecting and localizing epileptic cortex intraoperatively, the static system was upgraded to investigate histopathological abnormalities deep within the epileptic cortex, as well as to detect unique temporal pathophysiological characteristics of epileptic cortex. Detection of deep abnormalities within the epileptic cortex prompted a redesign of the fiberoptic probe. A mechanical probe holder was also designed and constructed to maintain the probe contact pressure and contact point during the time dependent measurements. The dynamic diffuse reflectance spectroscopy system was used to characterize in vivo pediatric epileptic cortex. The results of the study show that some unique wavelength dependent temporal characteristics (e.g., multiple horizontal bands in the correlation coefficient map g(λref = 800 nm, λcomp,t)) can be found in the time dependent recordings of diffuse reflectance spectra from epileptic cortex defined by ECoG.

La course à la miniaturisation requiert l'introduction d'architectures de transistors innovantes enremplacement des technologies conventionnelles sur substrat de silicium. Ainsi la technologie UTBB-FDSOI permet d'améliorer notablement l'intégrité électrostatique et assure une transition progressive vers les structures 3D multigrilles. Ces dispositifs diffèrent des structures conventionnelles par la présence d'un oxyde enterré qui va non seulement modifier l'électrostatique mais également introduire une nouvelle interface de type Si/SiO2 sujette à d'éventuelles dégradations. Par ailleurs, la réduction des dimensions des transistors s'accompagne d'une augmentation de la dispersion des paramètres électriques. En parallèle, le vieillissement de ces transistors introduit une forme additionnelle de variabilité : la variabilité temporelle, qu'il convient d'intégrer à cette composante moyenne de dégradation. Ce travail de thèse est développé sur quatre chapitres, où nous nous intéressons dans le premier chapitre aux évolutions technologiques nécessaires pour passer des technologies CMOS standards (40LP, 28LP) à cette technologie UTBB-FDSOI. Puis dans le second chapitre, nous abordons la dégradation moyenne des transistors et l'impact de l'architecture sur la fiabilité des dispositifs, étudiés sur les mécanismes de dégradations NBTI et HCI. Le troisième chapitre donne au niveau transistor une description analytique et physique de la variabilité temporelle induite par le NBTI. Enfin, cette variabilité temporelle est intégrée au niveau cellules SRAM dans le quatrième chapitre afin de prédire les distributions des tensions minimums de fonctionnement (Vmin) des mémoires SRAM. / The classical CMOS structure is reaching its scaling limits at the 20nm node and innovative architectures of transistors are required to replace these conventional Bulk transistors. UTBB-FDSOI transistors can improve significantly the electrostatic integrity and ensure a smooth transition to 3D multi-gates devices that will be required for sub-10nm nodes. The main difference compared to conventional transistor is related to the integration of a buried oxide (BOX) underneath the silicon film. This latter impacts the electrostatic behavior of these devices and introduces an additional Si/SiO2 interface which may be degraded due to ageing. It is then necessary to evaluate its impact on the NBTI and HCI reliability mechanisms. Besides, transistor scaling leads to an increasing variability which translates into an increased dispersion of the electrical parameters of the transistors. Meanwhile, time dependent variability due to ageing needs to be added to the average degradation component. This PhD done in STMicroelectronics R&D center is divided into four chapters: in the first one, the main technological developments necessary to keep on sustaining Moore's law requirements resulting in the UTBBFDSOI structure introduction is discussed. Then in the second chapter the architecture impact on the average reliability mechanism is discussed at transistor and Ring Oscillators' levels. In the third chapter, the time dependent variability due to NBTI is described and compared to time-zero variability. Finally the last chapter focuses on the SRAM cells reliability and a method is developed to predict minimum operating voltage (Vmin) distributions of SRAM memory.

Since the very beginning of the development of computers they have been used to accelerate the knowledge gain in science and research. Today they are a core part of most research facilities. Especially in natural and technical sciences they are used to simulate processes that would be hard to observe in real world experiments. Together with measurements from such experiments, simulations produce huge amounts of data that have to be analyzed by researchers to gain new insights and develop their field of science.