O objetivo principal de estudo deste trabalho são as estruturas localmente integráveis L e a fórmula de aproximação de Baouendi-Treves, segundo a qual qualquer solução homogênea de Lu = 0, pode, localmente, ser aproximada por polinômios nas suas integrais primeiras. A realização deste projeto requer um estudo rigoroso de alguns aspectos da teoria das estruturas involutivas e da teoria das distribuições. As principais referências são [2], [4] e [1]. / The main goal of this project is to study a locally integrable structures L and the Baouendi-Treves approximation formula, which states that every homogeneous solution of Lu = 0, can be, locally, approximated by polynomials in their first integrals. This result requires the rigorous study of some aspects of the involutive structures theory and of the distributions theory. The main references are [2], [4] e [1].

O principal objetivo desta dissertação é estudar um contraexemplo para o Décimo Quarto Problema de Hilbert no caso de dimensão n = 5, que foi apresentado por Arno van den Essen ([6]) em 2006 e que é baseado em um contraexemplo de D. Daigle e G. Freudenburg ([4]). Para isso, serão estudados os conceitos fundamentais da teoria de derivações e os princípios básicos das derivações localmente nilpotentes, bem como seus respectivos corolários. Dentre esses princípios encontra-se o Princípio 13, que garante que, se B é uma k- álgebra polinomial, digamos B = k[x1; ..., xn], (onde k é um corpo de característica zero) e D é uma derivação localmente nilpotente sobre B, então seu núcleo A = ker D satisfaz A = B &cap: Frac(A). Assim encontramos o contraexemplo esperado, ao mostrar que A não é finitamente gerado sobre k. Além disso, no apêndice deste trabalho, é dada uma prova para o caso de dimensão 1 do Décimo Quarto Problema de Hilbert. / The main objective of this thesis is to study a counterexample to the Hilberts Fourteenth Problem in dimension n = 5, which was presented by Arno van den Essen ([6]) in 2006 and that is based on a counterexample of D. Daigle and G. Freudenburg ([4]). For these purpose, we study the fundamental concepts of the theory of derivations and the basic principles of locally nilpotent derivations and their corollaries. Among these principles, Principle 13 ensures that if B is a k-algebra polynomial, say B = k[x1; ..., xn], (where k is a field of characteristic zero) and D is a locally nilpotent derivation on B, then its kernel A = ker D satisfies A = B ∩ Frac(A). Once we have proved that A is not finitely generated over k, we find the expected counterexample. In addition, in the appendix of this work is given a proof for the Hilberts Fourteenth Problemin dimension n = 1.

La discrétion acoustique est un enjeu majeur dans le domaine de la défense navale. Dans ce contexte, DCNS Research souhaite évaluer la capacité des métamatériaux acoustiques aléatoires localement résonnants à constituer une rupture technologique, comparativement aux matériaux anéchoïques actuels. Nous nous proposons de dimensionner, suite à une étude paramétrique conséquente, des structures contenant une répartition aléatoire d’inclusions sphériques. Des échantillons de matériaux localement résonnants ont été fabriqués. Leur réponse acoustique a été mesurée et confrontée aux prédictions issues de modèle. L’impact des résonances des inclusions et de l’angle d’incidence a été mis en évidence. Enfin, une méthode d’identification de leurs propriétés effectives a été développée à partir de mesures en réflexion et en transmission. Elle repose sur une configuration expérimentale originale. Des difficultés liées à l’extraction de la masse volumique dynamique sont mises en exergue. / Stealth is a major issue in naval defence. In this context, DCNS Research wants to know if locally-resonant acoustic metamaterials represent a technological breakthrough in comparison to current anechoic materials. We propose here a design of structures with randomly distributed spheres, based on a consequent parametric study. Samples of locally resonant materials were manufactured. Then, their acoustic response has been measured and compared to predictions based on multiple scattering theories. The presence of resonances and the impact of a non-null incidence angle have been highlighted. Finally, we developed a characterization method of the effective properties, from measurements of coefficients of reflection and transmission. Its design is based on an originally experimental setup. Difficulties coming from the retrieval of the dynamic mass density have been showed.

In this work, prestressed elasticity problem as a model of the so-called glacial isostatic adjustment (GIA) process is studied. The model problem is described by a set of partial differential equations (PDE) and discretized with a mixed finite element (FE) formulation. In the presence of prestress the so-constructed system of equations is non-symmetric and indefinite. Moreover, the resulting system of equations is of the saddle point form. We focus on a robust and efficient block lower-triangular preconditioning method, where the lower diagonal block is and approximation of the so-called Schur complement. The Schur complement is approximated by the so-called element-wise Schur complement. The element-wise Schur complement is constructed by assembling exact local Schur complements on the cell elements and distributing the resulting local matrices to the global preconditioner matrix. We analyse the properties of the element-wise Schur complement for the symmetric indefinite system matrix and provide proof of its quality. We show that the spectral radius of the element-wise Schur complement is bounded by the exact Schur complement and that the quality of the approximation is not affected by the domain shape. The diagonal blocks of the lower-triangular preconditioner are combined with inner iterative schemes accelerated by (numerically) optimal and robust algebraic multigrid (AMG) preconditioner. We observe that on distributed memory systems, the top pivot block of the preconditioner is not scaling satisfactorily. The implementation of the methods is further studied using a general profiling tool, designed for clusters. For nonsymmetric matrices we use the theory of Generalized Locally Toeplitz (GLT) matrices and show the spectral behavior of the element-wise Schur complement, compared to the exact Schur complement. Moreover, we use the properties of the GLT matrices to construct a more efficient AMG preconditioner. Numerical experiments show that the so-constructed methods are robust and optimal.

The forward-looking design trend in Very Large Scale Integrated (VLSI) is Systems-on-Chip (SoC). SoC aims to integrate multiple computation, communication and storage components into a single chip and targets high performance systems by elimination of most on-chip communication costs. It is agreed that running SoC components under control of a single clock is not feasible and clock distribution has been revealed as a critical obstacle. Asynchronous techniques can be exploited to relax strict timing constraints of traditional design methodologies. A less radical solution is Globally Asynchronous Locally Synchronous (GALS) systems which offer potential advantages in this respect, as it preserves system modularity and concentrates on communication aspects. The problem with GALS design is the relative lack of familiarity of traditional designers with this approach. To deal with this, a methodology is proposed to allow designers implement GALS systems at a higher abstraction level which is independent of technology, protocol, data encoding or any other details of circuit design. With the recent advances in concurrent programming, Communicating Sequential Processes (CSP) has gained popularity again. The CSP-based programming languages, like Go, have emerged to allow software designers to exploit the model toward implementing scalable softwares. CSP has a long history since 90's in the hardware domain, mainly utilised by the Asynchronous community. In this thesis, a novel high level synthesis framework is proposed, called eTeak, which enables the designers to implement GALS-like systems in a CSP-based language (Balsa) without concerning about the timing issues at system level. The proposed approach in this thesis takes advantage of synchronous elasticity to introduce a common timing discipline to the circuit which transforms it into a latency-insensitive system. A latency-insensitive system is able to tolerate dynamic changes in the computation and communication delays. This feature enables eTeak to raise the level of abstraction to the data-flow representation where functionality is separated from timing details. Therefore, it is possible for a designer to specify a large scale system by only concentrating on its functionality and postpone timing complexity to when synthesis takes place. Unlike many previous systems, the proposed design flow employs data-driven synthesis style to distribute controllers through the network which contributes to its modularity and enhanced concurrency. This facilitates partitioning into elastic blocks and is supposed to pave the road for further optimisations, such retiming and re-synthesis, using commercial EDA tools.

The purpose of the thesis is to evaluate the regulation and manner of deregulation in the Czech Republic. The first part describes regulation in general and interest groups approach to the deregulation of rents. In society there are many myths about rent control that are overturned at work. The rent control in the Czech Republic, the legal framework of regulation and regulation impacts are discussed in next part of the work. Then are described the impacts and possible ways of solving problems associated with deregulation. Ways of rent deregulation in selected foreign countries are compared with the way deregulation in the Czech Republic. In the practical part are analysed revenues and expenditures of owner of real estate property during the regulated years and modelled an example of fair rents made with regard to the cost of tenant and lessor.

The finite difference time domain (FDTD) method is commonly used for numerical simulations of the electromagnetic wave propagation in time domain. The FDTD method is easy to implement and the computational results are highly relevant to the analytical solution, so that the FDTD method is applied to variety application problems. However, the computational efficiency of the FDTD method is constrained by the upper limit of the temporal discretisation. The Courant Friedrich Lewy (CFL) stability condition limits the time step for the computation of the FDTD method, so that if the spatial discretisation of the computation is set to be small in order to obtain high accurate results, the size of the temporal discretisation need to be satisfy the CFL stability condition. The locally one dimensional FDTD (LOD-FDTD) method is unconditionally stable. The time step and the spatial step can be independently chosen for the computation of the LOD-FDTD method. The arithmetic operations of the LOD-FDTD method is fewer than that of the other implicit FDTD method, such as the Crank Nicolson FDTD (CN-FDTD) method and the alternating direction implicit FDTD (ADI-FDTD) method. Although the implementation of the LOD-FDTD method is simpler than that of the ADI-FDTD method,the numerical error in the computational results of the LOD-FDTD method is equivalent to that in the computational results of the ADI-FDTD method. In this thesis, a new three dimensional (3D) frequency dependent (FD) LOD-FDTD method is proposed. The one pole Debye model is incorporated into the 3D-FD-LOD-FDTD method in order to deal with practical applications. The proposed method is implemented in Fortran 90 and parallelised with OpenMP. A simulation model of the human phantom is developed in the 3D-FD-LOD-FDTD method with fine structures and frequency dependent dielectric properties of the human tissues, and numerical simulation of electromagnetic wave propagation inside the human head is shown.

Orientador: Jorge Tulio Mujica Ascui / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Computação Cientifica / Made available in DSpace on 2018-08-07T16:44:31Z (GMT). No. of bitstreams: 1 Takatsuka_Paula_D.pdf: 3540981 bytes, checksum: 643e40ac81900cf042cfe1cfb3737b0d (MD5) Previous issue date: 2006 / Resumo: Este trabalho estende teoremas clássicos da teoria de funções holomorfas de uma variável complexa para espaços localmente convexos de dimensão infinita. Serão dadas várias caracterizações de famílias normais, n¿ao apenas com relação à topologia compacto-aberta, mas também para outras topologias naturais no espaço de aplicações holomorfas. Teoremas de tipo Montel e de tipo Schottky, bem como outros resultados correlatos, ser¿ao estabelecidos em dimensão infinita para as diferentes topologias. Teoremas de limita¸c¿ao universal sobre famílias de funções holomorfas que omitem dois valores distintos ser¿ao formulados para espaços de Banach / Abstract: The present work extends some classical theorems from the theory of holomorphic functions of one complex variable to infinite dimensional locally convex spaces. Several characterizations of normal families are given, not only for the compact-open topology, but also for other natural topologies on spaces of holomorphic mappings. Montel-type and Schottky-type theorems and various related results are established in infinite dimension for these different topologies. Universal boundedness theorems concerning families of holomorphic functions which omit two distinct values are formulated for Banach spaces / Doutorado / Mestre em Matemática

abstract: Bivariate responses that comprise mixtures of binary and continuous variables are common in medical, engineering, and other scientific fields. There exist many works concerning the analysis of such mixed data. However, the research on optimal designs for this type of experiments is still scarce. The joint mixed responses model that is considered here involves a mixture of ordinary linear models for the continuous response and a generalized linear model for the binary response. Using the complete class approach, tighter upper bounds on the number of support points required for finding locally optimal designs are derived for the mixed responses models studied in this work. In the first part of this dissertation, a theoretical result was developed to facilitate the search of locally symmetric optimal designs for mixed responses models with one continuous covariate. Then, the study was extended to mixed responses models that include group effects. Two types of mixed responses models with group effects were investigated. The first type includes models having no common parameters across subject group, and the second type of models allows some common parameters (e.g., a common slope) across groups. In addition to complete class results, an efficient algorithm (PSO-FM) was proposed to search for the A- and D-optimal designs. Finally, the first-order mixed responses model is extended to a type of a quadratic mixed responses model with a quadratic polynomial predictor placed in its linear model. / Dissertation/Thesis / Doctoral Dissertation Statistics 2020

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