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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

An evaluation of Java and its application to the fifteen-puzzle

Hang, Raksas. January 1996 (has links)
Thesis (M.S.)--University of California, Santa Cruz, 1996. / Typescript. Includes bibliographical references (leaf 45).
32

Retirement Consumption Behavior: Evidence from HRS CAMS 2001-2009

Chiang, Mei-Fang 27 June 2012 (has links)
No description available.
33

Shape Based Object Detection and Recognition in Silhouettes and Real Images

Yang, Xingwei January 2011 (has links)
Shape is very essential for detecting and recognizing objects. It is robust to illumination, color changes. Human can recognize objects just based on shapes, thus shape based object detection and recognition methods have been popular in many years. Due to problem of segmentation, some researchers have worked on silhouettes instead of real images. The main problem in this area is object recognition and the difficulty is to handle shapes articulation and distortion. Previous methods mainly focus on one to one shape similarity measurement, which ignores context information between shapes. Instead, we utilize graph-transduction methods to reveal the intrinsic relation between shapes on 'shape manifold'. Our methods consider the context information in the dataset, which improves the performance a lot. To better describe the manifold structure, we also propose a novel method to add synthetic data points for densifying data manifold. The experimental results have shown the advantage of the algorithm. Moreover, a novel diffusion process on Tensor Product Graph is carried out for learning better affinities between data. This is also used for shape retrieval, which reaches the best ever results on MPEG-7 dataset. As shapes are important and helpful for object detection and recognition in real images, a lot of methods have used shapes to detect and recognize objects. There are two important parts for shape based methods, model construction and object detection, recognition. Most of the current methods are based on hand selected models, which is helpful but not extendable. To solve this problem, we propose to construct model by shape matching between some silhouettes and one hand decomposed silhouette. This weakly supervised method can be used not only learn the models in one object class, but also transfer the structure knowledge to other classes, which has the similar structure with the hand decomposed silhouette. The other problem is detecting and recognizing objects. A lot of methods search the images by sliding window to detect objects, which can find the global solution but with high complexity. Instead, we use sampling methods to reduce the complexity. The method we utilized is particle filter, which is popular in robot mapping and localization. We modified the standard particle filter to make it suitable for static observations and it is very helpful for object detection. Moreover, The usage of particle filter is extended for solving the jigsaw puzzle problem, where puzzle pieces are square image patches. The proposed method is able to reach much better results than the method with Loopy Belief Propagation. / Computer and Information Science
34

Can market incompleteness resolve asset pricing puzzles?

Freeman, Mark C. 06 August 2009 (has links)
No / This paper shows that the presence of persistent uninsurable risk concentrated in economic depressions has the potential to resolve two well¿known asset pricing puzzles. It is also shown that the presence of such risk in more normal economic expansions and recessions is likely to be much less relevant in determining equilibrium asset prices.
35

Sub-optimální algoritmy pro řešení úloh o přesouvání kamenů / Sub-optimal algorithms for solving sliding puzzles

Michalík, Petr January 2011 (has links)
Title: Sub-optimal algorithms for solving sliding puzzles Author: Petr Michalík Department: Department of Theoretical Computer Science and Mathematical Logic Supervisor: RNDr. Pavel Surynek, Ph.D. Supervisor's e-mail address: Pavel.Surynek@mff.cuni.cz In the present work techniques for solving the so-called sliding tiles puzzles, which generate optimal or sub-optimal solution, are studied. This thesis focuses especially on a specific variant of the puzzle: the (n^2-1)-puzzle. This work shows and compares current methods for solving this type of problem. A choosen method is a subject to a close analysis of complexity and is also implemented so that theoretical and experimental results could be confronted. An alternative sub-optimal algorithm is proposed and its theoretical analysis is presented. This algorithm is implemented as well and is compared with the existing algorithm. Both the theoretical analysis and the test results show that better (shorter) solutions can often be obtained using this alternative algorithm.
36

Observing Globalization using the Gravity Model of Trade / Observing Globalization using the Gravity Model of Trade

Dobiáš, Adam January 2016 (has links)
This thesis investigates application of the gravity model of international trade on measuring a distance coefficient, which is known to be a proxy to globalization. This estimation is performed on a dataset containing information on EU 27 countries through the years 1996 to 2014. The presence of 10 post- communist countries enabled the author to perform the estimation on transformative economies, which had been isolated from their western trade partners for over 40 years. The division of the dataset into the Western and Eastern Blocs enabled measurement of convergence of the intra-blocs trade - the second goal of this thesis. This measurement was done through newly introduced intra-blocs trade variables that enabled measurements of both directions of trade. Through the application of this model on 10 sections, these measurements could be performed on single trade components. The analysis shows a substantial heterogeneity between single sections both in distance coefficient and inter-blocs trade. An increase in the level of globalization was observed in 9 out of 10 sections and convergence of some sections between the blocs was also found. Finally, globalization was found to progress with varying speed within single SITC sections during periods of economic crises. Powered by TCPDF (www.tcpdf.org)
37

Interdisciplinaridade ou puzzle disciplinar? uma investigação em um curso de Letras/Inglês

Carvalho, Eliana Márcia dos Santos 16 September 2014 (has links)
Made available in DSpace on 2016-04-28T18:22:55Z (GMT). No. of bitstreams: 1 Eliana Marcia dos Santos Carvalho.pdf: 1733519 bytes, checksum: 389d367150a16a560af2d1ae69af84d4 (MD5) Previous issue date: 2014-09-16 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / This research in Applied Linguistics has two goals: to investigate the applicability of interdisciplinary actions in the university and to confront the concepts of interdisciplinarity by graduation teachers with the conceptions indicated in the Pedagogic Project of university course. Throughout this writing I tried to answer questions about the nature of teaching actions of a College degree in English Language Teaching that has a curriculum guided by the interdiciplinarity approach. Although there still no a ready definition to the term interdisciplinarity, the teachers conceptions were the main point to do a confrontation with the actions developed in the College Course. The interdisciplianrity approach is the focus of this work. The research has as its context the reality of a College degree in English Language Teaching from a multicampi University in the Brazilian Northeast . The developed studies provided an understanding of interdisciplinarity not as a "disciplinary puzzle", but as an educational attitude where personal, academic and methodological interconnections are possible. The methodology adopted was based on Ricoeur s hermeneutic (1990, 2006), where it was possible change as texts the interview and the questioner, instruments used to collect the information supporting this research. The teachers actions of the College degree in English Language from the campus focused refers to the to the field of interdisciplinary postulated by Japiassu (1976), Fazenda (1979, 2008, 2011, etc.), Pombo (1993, 2011). The study of História da Filosofia das Ciências in Lisboa-PT made me understand the interdisciplinarity as the current manifestation of the unity of science in school. The interpretation of texts from the questionnaires and interviews based on the pillars consistency, humility, expecting, detachment and respect - that guide interdisciplinary attitude, expresses an urgent necessity for curriculum reform and change of attitude in the educational environment / Esta pesquisa em Linguística Aplicada tem como objetivos: investigar a aplicabilidade de ações interdisciplinares no contexto universitário e confrontar conceitos de interdisciplinaridade dos professores da graduação com as concepções indicadas no Projeto Pedagógico de Curso de uma Universidade. Ao longo desta escrita, procurei responder indagações sobre a natureza das ações docentes de um Curso de Letras/Inglês que tem um currículo nas linhas de uma abordagem interdisciplinar. Embora ainda não exista uma pronta definição para o termo interdisciplinaridade, as concepções dos professores envolvidos nesta pesquisa foram o ponto principal para fazer uma confrontação com as ações desenvolvidas no curso de graduação. A abordagem interdisciplinar é o foco deste trabalho. Esta pesquisa tem como contexto a realidade de um Curso de Letras/Inglês de uma Universidade multicampi do nordeste brasileiro. Os estudos desenvolvidos possibilitaram a compreensão da interdisciplinaridade não como um puzzle disciplinar , mas como uma atitude educacional em que as interligações pessoais, metodológicas e acadêmicas são possíveis. A metodologia adotada foi a hermenêutica com base em Ricoeur (1990, 2006), na qual pude textualizar as entrevistas e questionários, instrumentos utilizados para coletar as informações que subsidiam esta pesquisa. As ações docentes do Curso de Letras/Inglês do campus em foco remete ao campo do estudo interdisciplinar postulado por Japiassu (1976), Fazenda (1979, 2008, 2011, etc.) e Pombo (1993, 2011). O estudo de História da Filosofia das Ciências em Lisboa-PT fez-me compreender a interdisciplinaridade como manifestação atual da unidade da ciência na escola. A interpretação dos textos oriundos dos questionários e da entrevista com base nos pilares coerência, humildade, espera, desapego e respeito que pautam a atitude interdisciplinar, expressa a necessidade de uma urgente reforma curricular e mudança de postura no ambiente educacional
38

Du système de parenté à la diversité génétique dans les populations humaines d'Asie du Sud-Est / From kinship system to genetic diversity in Southeast Asian human populations

Ly, Goki 12 December 2017 (has links)
L’évolution humaine n’est pas seulement génétique, elle est aussi culturelle, et les processus culturels et génétiques interagissent entre eux. Plus particulièrement, le système de parenté, en déterminant quand, où et avec qui les individus se reproduisent et élèvent leurs enfants, est un facteur clé de l’évolution génétique des populations humaines. Cependant la grande majorité des études de génétique des populations humaines ignorent l’existence de ces structures sociales. L’objectif de cette thèse est de remédier à ce manque en explorant par une approche pluridisciplinaire et quantitative l’influence des systèmes de parenté sur la diversité génétique de 12 populations d’Asie du Sud-Est présentant des règles de filiation patrilinéaire, matrilinéaire et cognatique associées à des règles de résidence patrilocale, matrilocale et multilocale. Nous avons tout d’abord mis en évidence que les systèmes de parenté se répercutent sur les variables ethno-démographiques d’importance pour l’évolution génétique des populations, et notamment sur les migrations maritales sexe-spécifiques. En particulier nous avons observé que les systèmes patrilinéaires et matrilinéaires ne sont pas symétriques. Il existe une plus grande flexibilité de la règle de résidence chez les populations patrilinéaires par rapport aux populations matrilinéaires. Cette différence a pour conséquence des taux de migrations d’hommes similaires entre les systèmes de parenté alors que les taux de migrations de femmes sont plus élevés chez les populations patrilinéaires que matrilinéaires. En outre, nous avons montré que les populations matrilinéaires et cognatiques avec résidence matrilocale prédominante ont une endogamie de village plus élevée que les populations patrilinéaires. Les raisons ethnologiques de ces observations sont discutées, particulièrement en lien avec l’hypothèse du « puzzle matrilinéaire ». Puis, nous avons exploré l’impact de ces différences ethno-démographiques entre populations suivant des systèmes de parenté différents sur leur diversité génétique uniparentale. Nous avons pu observer l’effet de la plus grande flexibilité de la règle de résidence chez les populations patrilinéaires : en effet, la diversité du chromosome Y suit le patron de migration des hommes, et est similaire entre les systèmes de parenté alors que celle de l’ADN mitochondrial suit le patron de migration de femmes et est plus élevée chez les populations patrilinéaires que matrilinéaires. Enfin, nous nous sommes intéressés à l’effet des systèmes de parenté sur la diversité autosomale et plus spécifiquement sur la consanguinité. Nous avons montré que le taux de consanguinité est plus élevé dans les populations matrilinéaires et cognatiques que dans les populations patrilinéaires, ce qui s’explique par la différence d’endogamie de village entre les systèmes de parenté.Pris ensemble, ces résultats montrent qu’il est nécessaire de prendre en compte le système de parenté comme une combinaison de règles (de filiation, de résidence et d’alliance) qui se croisent et interagissent, et dont l’effet sur la diversité génétique ne peut être appréhendé que par une analyse quantitative des variables ethno-démographiques pertinentes. / In humans, evolution is not only biological but also cultural. In addition, biological and cultural processes interact with each other. Kinship system is particularly interesting for population geneticists since it conditions when, where and with whom men and women reproduce and raise their children. It is therefore a key factor in the genetic evolution of human populations. However, most studies in human population genetics do not take into account the influence of social structures. The aim of this Phd thesis was to deepen our understanding of the influence of kinship system on genetic diversity. We undertook a pluridisciplinary and quantitative approach by collecting genetic and ethno-demographic data from 12 Southeast Asian populations exhibiting a wide variety of descent (matrilineal, patrilineal, or cognatic) and residence (matrilocal, patrilocal, or multilocal) rules.We first showed that kinship systems influence ethno-demographic variables that impacts the evolution of genetic diversity, notably sex-specific migrations. We found that patrilineal and matrilineal systems are not the symmetric opposite of each other. There was a higher residence rule flexibility in patrilineal populations compared to matrilineal populations. In consequence, male migration rates were similar between kinship systems whereas female migration rates were higher in patrilineal populations compared to matrilineal populations. In addition, we showed that matrilineal populations and cognatic populations with predominant matrilocal residence had a higher village endogamy compared to patrilineal populations. The ethnological reasons for these observations were discussed, in particular in the light of the matrilineal puzzle hypothesis. We then tested to which extent such ethno-demographic differences between populations following different kinship systems impact their uniparental genetic diversity. We could detect the impact of the higher residence rule flexibility in patrilineal populations: indeed, Y chromosome diversity followed the male migration pattern, and was similar between kinship systems, whereas mitochondrial DNA diversity followed the female migration pattern, and was higher in patrilineal populations compared to matrilineal populations. Finally, we focused on the influence of kinship systems on autosomal diversity, more specifically on inbreeding levels. We demonstrated that, due to larger village endogamy, inbreeding level was higher in matrilineal and cognatic populations compared to patrilineal populations Together these results showed that the kinship system has to be considered as the combination of a set of crossing and interacting rules (descent, residence and alliance), whose effects on genetic diversity can be disentangled only by going beyond categorizations and performing a quantitative assessment of relevant ethno-demographic variables.
39

Can a habit formation model really explain the Forward Premium Anomaly?

Vasconcelos, Jivago B. Ximenes de 07 August 2009 (has links)
Submitted by Daniella Santos (daniella.santos@fgv.br) on 2009-08-07T12:32:56Z No. of bitstreams: 1 Dissertação_Jivago_Vasconcelos.pdf: 444244 bytes, checksum: a4ae0c0f31d2c2371cb0e5b822e7da78 (MD5) / Approved for entry into archive by Antoanne Pontes(antoanne.pontes@fgv.br) on 2009-08-07T17:37:15Z (GMT) No. of bitstreams: 1 Dissertação_Jivago_Vasconcelos.pdf: 444244 bytes, checksum: a4ae0c0f31d2c2371cb0e5b822e7da78 (MD5) / Made available in DSpace on 2009-08-07T17:37:15Z (GMT). No. of bitstreams: 1 Dissertação_Jivago_Vasconcelos.pdf: 444244 bytes, checksum: a4ae0c0f31d2c2371cb0e5b822e7da78 (MD5) / Verdelhan (2009) shows that if one is to explain the foreign ex- change forward premium behavior using Campbell and Cochrane (1999) s habit formation model one must specify it in such a way to generate pro-cyclical short term risk free rates. At the calibration procedure, we show that this is only possible in Campbell and Cochrane s framework under implausible parameters speci cations given that the priceconsumption ratio diverges in almost all parameters sets. We, then, adopt Verdelhan s shortcut of xing the sensivity function (st) at its steady state level to attain a nite value for the price-consumption ratio and release it in the simulation stage to ensure pro-cyclical risk free rates. Beyond the potential inconsistencies that such procedure may generate, as suggested by Wachter (2006), with pro-cyclical risk free rates the model generates a downward sloped real yield curve, which is at odds with the data. / Verdelhan (2009) mostra que desejando-se explicar o comporta- mento do prêmio de risco nos mercados de títulos estrangeiros usando- se o modelo de formação externa de hábitos proposto por Campbell e Cochrane (1999) será necessário especificar o retorno livre de risco de equilíbrio de maneira pró-cíclica. Mostramos que esta especificação só é possível sobre parâmetros de calibração implausíveis. Ainda no processo de calibração, para a maioria dos parâmetros razoáveis, a razão preço-consumo diverge. Entretanto, adotando a sugestão proposta por Verdelhan (2009) - de xara função sensibilidade (st) no seu valor de steady-state durante a calibração e liberá-la apenas durante a simulação dos dados para se garantir taxas livre de risco prócíclicas - conseguimos encontrar um valor nito e bem comportado para a razão preço-consumo de equilíbrio e replicar o foward premium anomaly. Desconsiderando possíveis inconsistências deste procedimento, sobre retornos livres de risco pró-cíclicos, conforme sugerido por Wachter (2006), o modelo utilizado gera curvas de yields reais decrescentes na maturidade, independentemente do estado da economia - resultado que se opõe à literatura subjacente e aos dados reais sobre yields.
40

[en] INTERNATIONAL RESERVES AND THE EQUITY PREMIUM / [pt] RESERVAS INTERNACIONAIS E O EQUITY PREMIUM

18 October 2021 (has links)
[pt] Uma possível razão para a alta acumulação de reservas internacionais observada em diversos países está relacionada à vontade de se assegurar contra eventuais crises. Os modelos quantitativos de seguro, entretanto, possuem dificuldade para racionalizar as posições de reserva, a menos que os agentes exibam níveis relativamente altos de aversão ao risco. Esse resultado sugere uma conexão entre o puzzle de reservas internacionais e o equity premium puzzle, que exploramos nesta dissertação. Introduzimos preferências Epstein- Zin em um modelo padrão de default soberano com dívida de longo prazo e um ativo livre de risco, e o calibramos para a economia mexicana. Em seguida, precificamos um ativo de ação dentro do modelo e usamos simulações para estabelecer uma relação positiva entre o nível ótimo de reservas e o equity premium, conforme variamos o grau de aversão ao risco dos agentes domésticos. Usando uma estimativa do equity premium para o México, calibramos o nível de aversão ao risco e encontramos um nível ótimo de reservas internacionais próximo aos dados. Por fim, fornecemos evidência empírica consistente com a relação estabelecida no modelo. Especificamente, introduzimos estimativas do equity premium e, usando especificações crosssectional e de painel, documentamos uma associação positiva e robusta entre essas duas variáveis. / [en] Insurance is a possible explanation for the large holdings of international reserves observed in many countries. Quantitative models of the insurance motive, however, struggle to rationalize reserve positions, unless agents exhibit relatively high levels of risk aversion. This result suggests a connection between the international reserves puzzle and the equity premium puzzle, which we explore in this paper. We introduce Epstein-Zin preferences into a standard sovereign default model with long-term debt and a risk-free asset, and calibrate it to the Mexican economy. We then price an equity claim within the model, and use simulations to establish a positive relationship between optimal reserve holdings and the equity premium, as we vary the degree of risk aversion of domestic agents. Using an estimate of the equity premium for Mexico, we calibrate the level of risk aversion and find it produces an optimal level of international reserves that is close to the data. Finally, we provide empirical evidence consistent with the relationship established with the model. Specifically, we introduce estimates of the equity premium into standard regressions used to explain countries holdings of international reserves. Using both cross-sectional and panel specifications, we document a robust positive association between these two variables.

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