Central to human intelligence, visual categorization is a skill that is both remarkably fast and accurate. Although there have been numerous studies in primates regarding how information flows in inferiortemporal (ITC) and prefrontal (PFC) cortices during online discrimination of visual categories, there has been little comparable research on the human cortex. To bridge this gap, this thesis explores how visual categories emerge in prefrontal cortex and the ventral stream, which is the human homologue of ITC. In particular, cortical spatiotemporal plasticity in visual category learning was investigated using behavioral experiments, magnetoencephalographic (MEG) imaging, and statistical machine learning methods. From a theoretical perspective, scientists from work on non-human primates have posited that PFC plays a primary role in the encoding of visual categories. Much of the extant research in the cognitive neuroscience literature, however, emphasizes the role of the ventral stream. Despite their apparent incompatibility, no study has evaluated these theories in the human cortex by examining the roles of the ventral stream and PFC in online discrimination and acquisition of visual categories. To address this question, I conducted two learning experiments using visually-similar categories as stimuli and recorded cortical response using MEG—a neuroimaging technique that offers a millisecond temporal resolution. Across both experiments, categorical information was found to be available during the period of cortical activity. Moreover, late in the learning process, this information is supplied increasingly in the ventral stream but less so in prefrontal cortex. These findings extend previous theories by suggesting that the ventral stream is crucial to long-term encoding of visual categories when categorical perception is proficient, but that PFC jointly encodes visual categories early on during learning. From a methodological perspective, MEG is limited as a technique because it can lead to false discoveries in a large number of spatiotemporal regions of interest (ROIs) and, typically, can only coarsely reconstruct the spatial locations of cortical responses. To address the first problem, I developed an excursion algorithm that identified ROIs contiguous in time and space. I then used a permutation test to measure the global statistical significance of the ROIs. To address the second problem, I developed a method that incorporates domainspecific and experimental knowledge in the modeling process. Utilizing faces as a model category, I used a predefined “face” network to constrain the estimation of cortical activities by applying differential shrinkages to regions within and outside this network. I proposed and implemented a trial-partitioning approach which uses trials in the midst of learning for model estimation. Importantly, this renders localizing trials more precise in both the initial and final phases of learning. In summary, this thesis makes two significant contributions. First, it methodologically improves the way we can characterize the spatiotemporal properties of the human cortex using MEG. Second, it provides a combined theory of visual category learning by incorporating the large time scales that encompass the course of the learning.

在這篇論文裡，我們研究Diffy六邊形。本文一開始將Diffy六邊形視為Ducci序列，然後我們討論關於Ducci序列的一些性質。然而，Diffy六邊形事實上是可以旋轉與翻轉的，但是，我們所考慮的Ducci序列並不具備這樣的性質。所以，在本文的最後，我們討論在考慮旋轉與翻轉情況下的Ducci序列。 / In this thesis, we study the Diffy Hexagons: Initially, we regard a Ducci sequence as a Diffy Hexagon game and discuss some properties about Ducci sequences. However, a Ducci sequence isn't actually a Diffy Hexagon game due to the fact that regular hexagons has some symmetries under rotations and reflections, but the Ducci sequences don't. So, we apply an identification in the end.

The aim of this thesis is to investigate the traffic patterns in the mobile data networks. In this work, a simple Cellular Digital Packet Data (CDPD) network was modeled in order to be used in simulations. For the purpose of using in the CDPD model, a synthetic bursty traffic model was produced and using different traffic patterns some performance investigations were made in CDPD network. During the whole work, OPNET simulation tool was used. The CDPD network modeled by OPNET simulation tool was compared with a CDPD model described in the literature and the differences were shown. The new model has some new features: 1) Burst transmission of MAC blocks. 2) Exponential backoff. 3) New packet structures. 4) Frame segmentation and encapsulation into MAC layer frames. Using OPNET, a traffic having higher level of burstiness was produced and applied to the CDPD network model. Under the bursty traffic, some CDPD performance parameters were collected and according to the collected results some suggestions were given.

This thesis is a critical evaluation of the content, form and technique of traditional and modern praise poetry in Northern Sotho. Chapter 1 presents the aim of the study and the method of research and defines the concepts of poetry and praise poetry. Praise poetry is viewed from a traditional and modern perspective. Chapter 2 deals with the content and technique of praise poetry. Content consists of oral praise poetry lauding the heroic deeds of men in battles and casual encounters. Modern praise poetry comments on current events. Devices for rapid composition of the praises are discussed. Techniques differ between poets and according to time, place and occasion. Chapter 3 covers the traditional praises of chiefs, warriors, initiates, animals, birds, divining bones and totem praises, examining them from the perspective of content and form. The praises extol human achievements, peculiar animal characteristics and the interpretation of "mawa" of divining bones. Chapter 4 deals with the development and transition from traditional to modern form as well as the reciprocal influence. The content and form of modern praises of chiefs, academics, community leaders, animals, birds, divining bones, man-made objects and some natural phenomena are discussed. Many modern poets have also written praises of fictional characters. Chapter 5 compares oral and written praise poetry by concentrating on the similarities and differences between traditional and modern praise poetry. This study shows that there are differences in of theme, rhyme, beginning and ending, sentence length and significant emphasis on man-made objects such as cars and locomotives as exceptional modes of transport for commuters. Chapter 6 concludes the study and proves that praise poetry is a living or dynamic entity which will continue to exist. Praise poetry highlights persons, interpersonal relationships, attitudes and values derived from an African conceptions of the universe. / African Languages / D.Litt. et Phil (African Languages)

Made available in DSpace on 2015-07-22T20:50:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-11-25. Added 1 bitstream(s) on 2015-08-11T03:25:40Z : No. of bitstreams: 1 Publico-061.pdf: 1435875 bytes, checksum: 1afa77ce414913258d6fac6e89cdb379 (MD5) / Entre as alterações inerentes ao envelhecimento pode-se observar o surgimento do declínio cognitivo. Contudo, uma vida saudável com a prática de exercícios físicos parece gerar um efeito protetor contra o declínio cognitivo nos idosos. Segundo a literatura, tanto os exercícios aeróbios quanto os resistidos, quando praticados isoladamente, parecem beneficiar a cognição. Contudo, ainda não foi descrito se a combinação de ambas as modalidades acarretaria o mesmo beneficio. O objetivo do presente estudo foi investigar os efeitos que o treinamento combinado traria para a função cognitiva de idosos saudáveis. Foram selecionados trinta e três idosos saudáveis que foram distribuídos aleatoriamente em dois grupos: o Controle (N = 17) e o Combinado (N = 16). O grupo controle foi orientado a manter as suas atividades habituais, e o combinado participou de um programa de treinamento composto por exercícios físicos aeróbio e resistido, três vezes por semana, em dias alternados, por um período de seis meses. Os idosos, no início e ao final do protocolo, foram submetidos a avaliações físicas (ergoespirometria e teste de 1 Repetição Máxima - 1RM), cognitivas (por meio de medidas neuropsicológicas e neurofisiológicas), de humor, e de qualidade de vida, e também a análises sangüíneas (Fator de crescimento semelhante à insulina - IGF-1- e viscosidade do sangue). Os resultados demonstraram que nas avaliações físicas, tanto no consumo de oxigênio (p=0,01) quanto na 1RM (p=0,001), o grupo experimental, após o treinamento, apresentou uma diferença significativa em relação ao grupo controle. As variáveis relativas à composição corporal também tiveram diferenças significativas após a intervenção, ocorrendo uma diminuição da massa de gordura (p=0,016) e um aumento da massa livre de gordura (p=0,016). Além disso, no mesmo tipo de comparação, o grupo combinado, após um período de seis meses, apresentou um melhor desempenho nos seguintes testes: Figura Complexa de Rey e Taylor (p=0,01); Toulouse, no qual obtiveram um percentil maior na qualidade (p=0,045); Semelhanças (p=0,003); e Soma de todas das tentativas no teste de Pares Verbais Associados (p=0,043). Não foram observadas diferenças estatísticas nas demais análises. Desta forma, pode-se concluir que o treinamento físico combinado foi capaz de aumentar a força e a capacidade aeróbia de idosos saudáveis, tendo ocorrido também uma melhora na habilidade de abstração, no controle inibitório, na memória de curto prazo e na aprendizagem, / Among the changes associated with aging there is a cognitive decline. However, a healthy life style, such as physical exercise seems to generate a protective effect against this cognitive decline. The literature has shown that both aerobic and the resistance exercise, when practiced in isolation seem to result in benefits to cognition. Yet it is not described if the combination of both methods would result in the same benefit. The aim of this study was to investigate the effects of combined training on cognitive function in health elderly. Were select thirty-three elderly subjects who were randomly divided into two groups: Control (N = 17) and Combined (N = 16). The control group was instructed to maintain their usual activities and the combined group participated in a training program composed by aerobic and resistance exercise, three times per week on alternate days for a period of six months. Both groups underwent a physical assessment (spirometry and testing of 1 Repetition Maximum - 1RM), cognitive (through neurophysiological and neuropsychological measures), mood, quality of life and blood tests (Insulin-like growth factors type 1- IGF-1 - and blood viscosity) at the beginning and the end of the protocol. The results showed that in the physical assessments, both oxygen consumption (p = 0.01) and 1RM (p = 0.001), the experimental group after training showed a significant difference when compared to the control group. The variables relating to body composition also showed significant differences after the intervention, causing a decrease in fat mass (p = 0.016) and an increase in fat-free mass (p = 0.016). Moreover, the same type of comparison, the combined group, after a period of six months, performed better in the following tests: Rey Complex Figure and Taylor (p = 0.01); Toulouse, which obtained a percentile in the quality (p = 0.045); Similarities (p = 0.003); and Sum of all the attempts to test Verbal Associated Pairs (p = 0.043). There were no statistical differences in the other analysis. Thus, the conclusion is that the combined training can increase both strength and aerobic capacity in healthy elderlies, affecting an improvement in the ability of abstraction, inhibitory control, short-term memory and learning regardless of serum IGF-1 and blood viscosity. / TEDE / BV UNIFESP: Teses e dissertações

A prestudy indicated superior accuracy and convergence properties of apseudo-spectral method compared to a spline-based method implemented byCòrdoba et al. in 2005 when solving the α-patches problem. In this thesis wefurther investigate the numerical properties of the pseudo-spectral method and makeit more robust by implementing the Nonequispaced Fast Fourier Transform. Wepresent a more detailed overview and analysis of the pseudo-spectral method and theα-patches problem in general and conclude that the pseudo-spectral method issuperior in regards to accuracy in periodic settings.

Esta dissertação apresenta a edição fac-similar e diplomática em perspectiva genética de 53 notas de planejamento do romance Avalovara de Osman Lins. Esta seleção permitiu verificar quais foram os procedimentos empregados na composição do texto, da estrutura rigorosa do livro e o registro da utilização destas notas na obra publicada em 1973. A edição contempla documentos autógrafos, datiloscritos e impressos rasurados que, de modo geral, contêm um discurso indicativo. Com isso, é possível perceber certas particularidades relacionadas ao processo de criação do romance além de estabelecer novas propostas de estudo para a obra. / This dissertation presents the diplomatic and fac-simile edition of 53 planning notes of the Avalovara, a novel by Osman Lins, through a genetic perspective. The selection was limited to these documents in order to check the procedures employed in the text composition and in its rigorous structure, as well as the record of the use of these notes in the volume published in 1973. The edition includes handwritten, typed and scrapped printed documents that, in general, display an indicative discourse. Through this edition, it is possible both to notice certain peculiarities related to the creative process of the novel and to establish new perspectives of study for the novel.

Esse trabalho é um estudo sobre circuitos resistivos que apresentam a característica da autossimilaridade em sua configuração. A construção desses circuitos é feita de uma maneira recursiva, de forma análoga a um fractal autossimilar. Os circuitos são analisados pelas suas resistências equivalentes, sendo obtida uma condição para convergência desse valor. Os conceitos auxiliares necessários ao tema desta dissertação abordam a representação de um circuito resistivo como um grafo, além de conceitos envolvendo fractais autossimilares. São propostas ao final de cada capítulo atividades interdisciplinares acessíveis a alunos de ensino médio, com conteúdos envolvendo resistência equivalente, sequências, conjuntos, e noções de área e perímetro. / This work is a study of resistive circuits which present a characteristic of self similarity in their configuration. The construction of these circuits is made in a self recursive way, analogously to a self similar fractal. The circuits are analyzed by their equivalent resistance, and a condition for convergence of this quantity is obtained. Auxiliary concepts that are necessary to this dissertation theme treat the resistive circuit as a graph, and concepts involving self similar fractals. It is proposed at the end of each chapter interdisciplinary activities that are accessible to high school students, with topics involving equivalent resistence, sequences, sets, and notions of area and perimeter.

Este trabalho visa dar uma contribuição para o aumento de eficiência no fluxo de projeto de sistemas integrados, especificamente na avaliação de desempenho da comunicação entre os seus blocos componentes. É proposto o uso de modelagem e simulação de hardware em alto nível, no nível de transações, denominado TLM, para aproveitar a redução de esforço e tempo que se pode oferecer ao projeto de sistemas integrados, diferentemente de enfoques convencionais em níveis mais baixos de descrição, como o nível de registradores (RTL). É proposta uma forma de análise do tráfego intrachip produzido na comunicação de elementos do sistema, visando-se o uso dos resultados obtidos para descrição de geradores de tráfego. A principal contribuição deste trabalho é a proposta da análise de séries de tráfego obtido durante simulação de plataformas de hardware descritas no nível TLM usando-se métodos estatísticos conhecidos da área de estudo de séries temporais. A análise permite ao projetista ter maior compreensão da natureza estatística do tráfego intrachip, denominada dependência de curta ou longa duração (SRD e LRD), para o posterior ajuste de modelos usados na geração de séries sintéticas que representem tal natureza. Os resultados da análise mostraram que o tráfego obtido por simulação TLM tem natureza similar em relação ao da do tráfego obtido por simulação num nível mais baixo de abstração, do tipo de precisão por ciclos, indicando que o tráfego TLM pode ser usado para a representação do tráfego intrachip. Outra contribuição deste trabalho é a proposta de ajuste de modelos paramétricos autossimilares usando-se a decomposição da série de tráfego original, tendo sido feita uma comparação dos resultados desta com o ajuste convencional feito a modelos sem decomposição. Estas contribuições foram agrupadas dentro de uma metodologia detalhada, apresentada neste documento, para a qual experimentos foram realizados. Os resultados a partir das séries sintéticas autossimilares geradas pelos modelos estimados, apresentaram semelhança nos indicadores de SRD e LRD em relação às séries originais TLM, mostrando ser favorável o uso futuro destas séries sintéticas na implementação de geradores de tráfego. / It is objective of this work to make a contribution to improve the efficiency of the integrated systems design flow, specifically on the evaluation of communication performance between component blocks. The use of high level hardware modeling and simulation, at the transaction level, known as TLM, is proposed, in order to take advantage of the reduction of effort and time for the integrated system design; that in contrast to the traditional approaches, which use lower hardware description level, such as register transfer level (RTL). A methodology to evaluate the intra-chip traffic produced by the communication between system elements is proposed. The main contribution of this work is the analysis of traffic time series obtained by simulation of hardware platforms modeled in TLM, using well-known statistical methods for time series analysis. The analysis allows the system developer to understand the statistical nature of the intra-chip traffic, also known as short and long range dependence (SRD and LRD), for later adjustment and accurate representation of the traffic nature in synthetic series. The analysis results have shown that traffic traces obtained by TLM simulation has similar statistical nature as the traffic traces obtained at lower abstraction level, as cycle accurate type, which indicates that TLM traffic could be used to represent intrachip traffic. Another contribution of this work is a fitting procedure to auto similar parametric models thought the decomposition of the original traffic, and its comparison to the results of the conventional fitting, when applied to models that are not decomposed. These contributions were grouped and included in the detailed methodology presented in this document, being a series of experiments carried out. The results related to self-similar synthetic series, obtained from the fitted models, have shown similarity to the SRD and LRD indicators of the original TLM series, what favors the use of synthetic series future for the implementation of traffic generators.

Ce travail de thèse porte sur l'étude de systèmes dynamiques substitutifs. Les substitutions ont historiquement été introduites pour décrire la suite des sommes des chiffres modulo 2 en base 2 . On étudie des propriétés de la suite somme des chiffres et notamment les propriétés des densités asymptotiques d'ensembles liés aux autocorrélations de fonctions arithmétiques définies par les fonctions somme des chiffres. On démontre notamment un théorème de la limite centrale pour ces densités. On étudie également les propriétés de régularité de la fonction de pression dans le cadre du formalisme thermodynamique, introduit par Bowen, Ruelle et Sinaï, pour une famille de potentiels définis en terme de distance à l'attracteur de la substitution de k-bonacci. On démontre la convergence des itérés de l'opérateur de renormalisation introduit par Baraviera, Leplaideur et Lopes vers un point fixe pour cette même famille de potentiels. Enfin, on étudie des propriétés de régularité de certaines mesures spectrales associées à des pavages auto-similaires en s'appuyant sur des travaux de Bufetov et Solomyak portant sur les déviations des sommes ergodiques dans le cas de l'action par translation de \R^d sur les pavages auto-similaires de R^d. On démontre qu'après renormalisation, ces mesures spectrales se comportent comme des mesures de Radon autour de zér / In the present work we study substitutive dynamical systems. Historically, substitutions have been introduced in order to describe the sequence of the sum-of-digits mod 2 in base 2. We study some properties of densities of sets defined by sum-of-digits functions, sets which are linked with autocorrelations of some arithmétic functions. We prove that these densities are usually normally distributed. We also study the regularity of the pressure function in the framework of the thermodynamics formalism, introduced by Bowen, Ruelle and Sinaï, for a family of potentials defined in terms of distance to the attractor of the k-bonacci substitution. We also show that the iterations of the renormalisation operator defined by Baraviera, Leplaideur and Lopes converges towards a fixed point of this operator. Finally we study the regularity of some spectral measures associated to self-similar tilings using mostly works from Bufetov and Solomyak on the deviations of ergodic sums for the action of translations by vectors in R^d on self-similar tilings of R^d. We prove that, afeter renormalisation, these spectral measures behave like Radon measures around