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The game of Hex is a board game that belongs to the family of Shannon games, which are connection-oriented games where players must secure certain connected components in graphs. The problem of solving Hex is a decision problem complete in PSPACE, which implies that the problem is NP-Hard. Although the Hex problem is difficult to solve, there are a number of problem reduction methods that allow solutions to be found for small Hex boards within practical search limits. The present work addresses two problems, the problem of solving the game of Hex for small board sizes and the problem of creating strong artificial Hex players for larger boards. Recently, a leading Hex solving program has been shown to solve the 7x7 Hex board, but failed to solve 8x8 Hex within practical limits. This work investigates Hex-solving techniques and introduces a series of new search optimizations with the aim to develop a better Hex solver. The most significant of these new optimization techniques is a knowledge base approach that stores and reuses search information to prune Hex-solving searches. This technique involves a generalized form of transposition table that stores game features and uses such features to prove that certain board positions are winning. Experimental results demonstrate a knowledge base Hex solver that significantly speeds up the solving of 7x7 Hex. The search optimization techniques for Hex solvers given here are highly specialized. This work reports on a search algorithm for artificial Hex players, called Pattern Enhanced Alpha-Beta search that can utilize these optimization techniques. On large board positions, an artificial Hex player based on the Pattern Enhanced Alpha- Beta search can return moves in practical times if search depths are limited. Such a player can return a good move provided that the evaluated probabilities of winning on board positions at the depth cut-offs are accurate. Given a large database of Hex games, this work explores an apprenticeship learning approach that takes advantage of this database to derive board evaluation functions for strong Hex playing policies. This approach is compared against a temporal difference learning approach and local beam search approach. A contribution from this work is a method that can automatically generate good quality evaluation functions for Hex players.

Thesis--University of Missouri, School of Mines and Metallurgy, 1908. / R. E. Hoffman determined to be Ray Eugene Hoffman from "Forty-First Annual Catalogue. School of Mines and Metallurgy, University of Missouri". The entire thesis text is included in file. Typescript. Illustrated by author. Title from title screen of thesis/dissertation PDF file (viewed February 26, 2009)

We introduce the Effective Number of Issues measure for e-participation efficiency. This novel index is based on the Shannon entropy measure of biodiversity and summarizes the amount of information gained through an e-participation project in one number. This makes the comparison between different e-participation projects straightforward and lays the foundation for the rigorous analysis of success factors of e-participation projects in a data-driven way. After providing the formula and rationale for the new measure we use the ENI index to benchmark the idea generation process for the digital agenda Vienna against other projects. It turns out that the efficiency of this project is significantly higher than those observed for other cases. We conjecture that this can be attributed to the user-friendly design of the software platform and the effective communication strategy of the process management. Finally, suggestions for further research are given. (authors' abstract)

Made available in DSpace on 2015-07-22T20:50:18Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-08-26 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Conselho Nacional de Pesquisa e Desenvolvimento (CNPq) / World Health Organization (WHO) / Howard Hughes Medical Institute / Proteinas de adesao celular sao essenciais para a invasao celular do hospedeiro mamifero pelo parasita Trypanosoma cruzi. Neste trabalho, nos mostramos que membros de gDispersed Gene Family-1 h, originalmente descrita como uma familia de sequencias nucleares repetitivas presente em varios cromossomos e compondo a terceira maior familia genica especifica deste parasita, contem caracteristicas de adesinas, incluindo quatro segmentos com similaridade significante a sequencia da subunidade ƒÀ7 de integrina humana. Ensaios de biotinilacao da superficie de parasitas e citometria de fluxo com anticorpos anti-DGF-1 indicaram que os membros dessa familia genica sao expressos na superficie das formas tripomastigotas. A genealogia de DGF-1, inferida por algoritmos de rede a partir de dados do Projeto Genoma da linhagem CL Brener de T. cruzi, sugere que essa familia genica pode ser dividida em pelo menos tres grupos com diferentes padroes de distribuicao de seus dominios funcionais. Analisando o perfil de uso dos codons, observou-se que as copias expressas apresentavam um uso preferencial de codons, favorecendo as bases GC, ao passo que copias nao-expressas, incluindo alguns pseudogenes, apresentavam uma distribuicao homogenea no uso de codons. A entropia informacional de Shannon foi utilizada como uma medida da variabilidade de sequencia e revelou que quatro segmentos de alta entropia coincidem com modulos funcionais putativos das proteinas preditas. Contradizendo a ideia de que alta variabilidade esta associada a selecao positiva, os resultados de dois testes distintos de selecao mostraram que posicoes altamente variaveis nao estao necessariamente sob selecao positiva. Nossa hipotese e de que membros de DGF-1 estao associados com a habilidade do T. cruzi se ligar a proteinas da matriz extracelular, como fibronectina e laminina, e especulamos sobre os mecanismos que gerariam diversidade nessas moleculas na ausencia de selecao. / Surface adhesion proteins are essential for Trypanosoma cruzi invasion of mammalian cells. Here we show that Dispersed Gene Family-1 (DGF-1) members, previously identified as nuclear repeated sequences present in several chromosomes and comprising the third largest T. cruzi-specific gene family, have conserved adhesin motifs including four segments with significant similarity to human beta 7 integrin. Flow cytometry and biotinylation assays with anti-DGF-1 antibodies indicated that, as expected, DGF-1 members are expressed on the trypomastigote surface. The DGF-1 genealogy, inferred using T. cruzi Genome Project data and network phylogeny algorithms, suggests that this gene family is separated in at least three groups with differential distribution of functional domains. To identify which members of this gene family are expressed we used a combined approach of RT-PCR and codon usage profiles, showing that expressed members have a very biased codon usage favoring GC whereas non-expressed members have a homogeneous distribution. Shannon information entropy was used to measure sequence variability and revealed four major high entropy segments in the extracellular domain of DGF-1 overlapping with important putative functional modules of the predicted proteins. Testing for natural selection, however, indicated that these high entropy segments were not under positive selection, which contradicts the notion that positive selection is the cause of high variability in specific domains of a protein relative to other less variable regions in the same molecule. We hypothesize that members of the DGF-1 family are associated with the ability of T. cruzi to bind extracellular matrix proteins, such as fibronectin and laminin, and speculate on mechanisms that would be generating the localized diversity in these molecules in the absence of selection. / FAPESP: 03/05317-0 / TEDE / BV UNIFESP: Teses e dissertações

Made available in DSpace on 2014-06-11T19:22:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-10Bitstream added on 2014-06-13T20:10:06Z : No. of bitstreams: 1 silva_da_me_sjrp.pdf: 1617803 bytes, checksum: ac272edc3fa2d00a58fa6e743064acda (MD5) / Embolização e quimioembolização são exemplos de procedimentos minimamente invasivos aplicados em medicina com objetivo de evitar e/ou amenizar efeitos colaterais causados por tratamentos e intervenções cirúrgicas convencionais. Partículas de poli(álcool vinílico) (PVA) destacam-se entre os materiais utilizados nesses procedimentos por apresentarem características físico-químicas desejáveis como elevada compressibilidade, biocompatibilidade e biodegradabilidade. A proposta deste trabalho foi sintetizar e caracterizar microesferas de PVA/PVAc com tamanhos de partículas entre 30µm e 1200µm por reação de polimerização em suspensão seguida por uma etapa de saponificação. Além disso, estudar a influência da concentração de solução alcalina no processo de saponificação. A caracterização morfológica e estrutural foi feita com auxílio das técnicas de microscopia eletrônica de varredura (MEV) e difração de raios-X (DRX). Além da caracterização físico-química, foi realizado o estudo histopatológico mediante implante subcutâneo das partículas em ratos, análise de dimensão fractal e entropia de Shannon. Os resultados mostraram que a concentração de solução alcalina exerce forte influência na cristalinidade, coloração e características superficiais do polímero obtido. As partículas com alta cristalinidade (saponificadas com solução 25 mol/L de NaOH) induziram à reação inflamatória similar ao comportamento observado para partículas disponíveis comercialmente, enquanto que as partículas menos cristalinas (saponificadas com solução 4 mol/L de NaOH) resultaram em baixa intensidade de reação inflamatória no tecido celular subcutâneo dos ratos. Dimensão fractal... / Embolization and chemoembolization are examples of minimally invasive procedures applied in medicine in order to avoid and/or reduce side effects caused by conventional treatments and surgeries. Particles of poly(vinyl alcohol) (PVA) stand out among these materials due to desirable physical and chemical characteristics such as high compressibility, biocompatibility and biodegradability. The purpose of this study was to synthesize and characterize PVA/PVAc microspheres with sizes between 30µm and 1200µm by reaction of suspension polymerization step followed by a process of saponification. Moreover, study the influence of the concentration of alkaline solution in the process of saponification. The morphological and structural characterization was made with scanning electron microscopy (SEM) and X-ray diffraction (XRD). In addition to the physico-chemical characterization, it was carried the histopathological study by subcutaneous implantation of particles in rats, analysis of fractal dimension and Shannon´s entropy. The results indicated that the concentration of alkaline solution strongly influence the crystallinity, color and surface characteristics of the polymer. Highly crystalline particles (saponified with 25 mol/L NaOH) induced inflammatory reaction similar to the behavior observed for the commercial particles, while particles with lower crystallinity (saponified with 4 mol/L NaOH) presented lower inflammation in the subcutaneous tissue of rats. Fractal dimension and Shannon´s entropy showed satisfactory correlation with the histopathological analysis: the values have changed as the permanence time of particles in rats, behavior was satisfactory from a clinical standpoint because it corroborates the qualitative changes observed in the subcutaneous tissues in response to disturbance of the immune... (Complete abstract click electronic access below)

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / In this work we study from both classical and quantum point of view the position dependent mass harmonic oscillator (PDMHO). Classically, we use the Legendre transformation to find the Hamiltonian of the system. Next, we define two functions, and , to simplify the hamiltonian of the PDMHO. By using the Poisson algebra we find the expressions for the position and moment. At last, by using a canonical transformation we relate the equations of the PDMHO to those of the simple harmonic oscillator (SHO). Quantically, we write the Hamiltonian of the PDMHO in terms of the operators and . Next, we consider that these operators satisfy the same algebra that those of the SHO. By assuming that both the classical and quantum PDMHO have the same form, we are able to find a simple form for the PDMHO Hamiltonian. Finally, by transforming the SchrÃdinger equation (SE) of the PDMHO into that of the SHO, we can write the wave function of the PDMHO in terms of that of the SHO. We will study two time-dependent systems, namely and , we observe that as , they tend to a simple harmonic oscillator. For each system we find the position and momentum (classical study), as well as the wave-function (quantum study). For both systems we analyze the the position e momentum uncertainty, the product uncertainty, the fisher information and Shannon entropy, for the ground state, as a function of the parameter . / Neste trabalho estudamos clÃssica e quanticamente o oscilador harmÃnico com massa dependente da posiÃÃo (OHMDP). Na parte clÃssica, utilizamos a transformaÃÃo de Legendre para encontrar a hamiltoniana do sistema. A seguir definimos duas funÃÃes e para escrevermos a hamiltoniana do OHMDP de uma forma mais simples. Utilizando a Ãlgebra de Poisson encontramos as expressÃes para a posiÃÃo e o momento. Por fim, atravÃs de uma transformaÃÃo canÃnica veremos como relacionar as equaÃÃes do OHMDP com aquelas do oscilador harmÃnico simples (OHS). Na parte quÃntica, escrevemos a hamiltoniana do OHMDP em termos de operadores e . Em seguida, vamos supor que estes operadores satisfaÃam a mesma relaÃÃo de comutaÃÃo que os operadores abaixamento e levantamento do OHS. Analisando que condiÃÃo deve ser satisfeita para que os osciladores OHMDP clÃssico e quÃntico tenham o mesmo potencial, encontramos uma forma simplificada da hamiltoniana do OHMDP. Em seguida, transformamos a equaÃÃo de SchrÃdinger (ES) para o OHMDP na ES para o OHS. Assim, obtemos a funÃÃo de onda do OHMDP em termos da funÃÃo de onda do OHS. Estudaremos dois sistemas com massa dependente da posiÃÃo, a saber: e , vemos que quando , recaÃmos no OHS. Para cada sistema encontraremos a posiÃÃo e o momento (estudo clÃssico), bem como a funÃÃo de onda (estudo quÃntico). Para os dois sistemas analisaremos tambÃm o comportamento da incerteza na posiÃÃo, incerteza no momento, produto de incerteza, informaÃÃo de Fisher e entropia de Shannon, para o estado fundamental, em funÃÃo do parÃmetro de deformaÃÃo .

Interference is a key limiting factor in modern communication systems. In a wireless cellular network, the performance of cell-edge users is severely limited by the intercell interference. This thesis studies the use of interference-channel and relay-channel techniques to mitigate intercell interference and to improve the throughput and coverage of cellular networks. The aim of this thesis is to demonstrate the benefit of the proposed interference mitigation schemes through both information theoretical studies and applications in the cellular network. There are three mains results in this thesis: First, it is shown that for the $K$-user cyclic Gaussian interference channel, where the $k$th user interferes with only the ($k -1$)th user (mod $K$) in the network, the Etkin-Tse Wang power splitting strategy achieves the capacity region to within 2 bits in the weak interference regime. For the special 3-user case, this gap can be sharpened to $1\frac{1}{2}$ bits by the time-sharing technique. Second, it is shown that for a two-user Gaussian interference channel with an in-band-reception and out-of-band transmission relay, generalized hash-and-forward together with Han-Kobayashi information splitting can achieve the capacity region of this channel to within a constant number of bits in a certain weak-relay regime. A generalized-degrees-of-freedom analysis in the high signal-to-noise ratio regime reveals that in the symmetric channel setting, each common relay bit improves the sum rate up to two bits. The third part of this thesis studies an uplink multicell joint processing model in which the base stations are connected to a centralized processing server via rate-limited digital backhaul links. This thesis proposes a suboptimal achievability scheme employing the Wyner-Ziv compress-and-forward relaying technique and successive-interference-cancellation decoding. The main advantage of the proposed approach is that it results in achievable rate regions that are easily computable, in contrast to previous schemes in which the rate regions can only be characterized by exponential number of rate constraints.

La première partie de la thèse introduit une méthode de déquantification de l'image qui améliore les propriétés statistiques du champ de gradient. Nous appliquons notre méthode à la détection de segments significatifs développée par Agnès Desolneux.La seconde partie présente une méthode d'évaluation du flou dans les images naturelles. Nous tirons profit du scale space morphologique pour permettre une évaluation aussi précise que possible de la quantité de flou local, sans connaissances sur le noyau.