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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.
61

Models of complexity in Robert Coover's John's wife and the adventures of Lucky Pierre

Bem, Isabella Vieira de January 2005 (has links)
Esta tese de doutorado analisa dois romances do escritor Norte-Americano Robert Coover como exemplos de escrita hipertextual e de hiperficção no suporte do livro de papel. A complexidade dos romances John's Wife e The Adventures of Lucky Pierre integra os elementos culturais característicos da atual fase do capitalismo e as práticas tecnologizadas que vêm forjando uma subjetividade diferente na escrita e leitura hipertextual, a subjetividade pós-humana. Os modelos da complexidade dos romances derivam do conceito de atratores estranhos da Teoria do Caos e de rizoma da Nomadologia. As transformações no grau de corporeidade dos personagens estabelecem o plano em que se discute a turbulência e a pós-humanidade. As noções de padrões dinâmicos e atratores estranhos e os conceitos do Corpo sem Órgãos e do Rizoma são interpretados para se revisar a narratologia e chegar a categorias apropriadas ao estudo dos romances. A leitura exercitada nesta tese põe em prática a proposta de leitura corpórea de Daniel Punday. As mudanças no grau de materialidade dos personagens são associadas aos estágios de ordem, turbulência e caos na estória, agindo sobre a constituição da subjetividade ao longo do processo de leitura. A inscrição dos planos de consistência que Coover realiza para se contrapor à linearidade e acomodar as feições hipertextuais nas narrativas em papel descreve a trajetória rizomática dos personagens. O presente estudo leva a concluir que a narrativa hoje se constitui antes como um regime numa relação rizomática com outros regimes na prática cultural do que como forma e gênero predominantemente literários. Também se conclui que a subjetividade pós-humana emerge alinhada a uma identidade de classe que tem nos romances hipertextuais a sua forma literária predileta. / This doctoral dissertation analyzes two novels by the American novelist Robert Coover as examples of hypertextual writing on the book bound page, as tokens of hyperfiction. The complexity displayed in the novels, John's Wife and The Adventures of Lucky Pierre, integrates the cultural elements that characterize the contemporary condition of capitalism and technologized practices that have fostered a different subjectivity evidenced in hypertextual writing and reading, the posthuman subjectivity. The models that account for the complexity of each novel are drawn from the concept of strange attractors in Chaos Theory and from the concept of rhizome in Nomadology. The transformations the characters undergo in the degree of their corporeality sets the plane on which to discuss turbulence and posthumanity. The notions of dynamic patterns and strange attractors, along with the concept of the Body without Organs and Rhizome are interpreted, leading to the revision of narratology and to analytical categories appropriate to the study of the novels. The reading exercised throughout this dissertation enacts Daniel Punday's corporeal reading. The changes in the characters' degree of materiality are associated with the stages of order, turbulence and chaos in the story, bearing on the constitution of subjectivity within and along the reading process. Coover's inscription of planes of consistency to counter linearity and accommodate hypertextual features to the paper supported narratives describes the characters' trajectory as rhizomatic. The study led to the conclusion that narrative today stands more as a regime in a rhizomatic relation with other regimes in cultural practice than as an exclusively literary form and genre. Besides this, posthuman subjectivity emerges as class identity, holding hypertextual novels as their literary form of choice.
62

Padrões e pseudo-aleatoriedade usando sistemas complexos / Patterns and pseudo-randomness using complex systems

Marina Jeaneth Machicao Justo 07 December 2017 (has links)
Neste trabalho demonstramos que padrões e aleatoriedade estão intimamente relacionados, ao contrário do que intuitivamente é considerado como campos opostos. Esta abordagem visa dois propósitos: por um lado, obter vantagens das propriedades caóticas para medir pseudo-aleatoriedade, e por outro lado, extrair padrões de diagramas espaço-tempo como método de reconhecimento de padrões. Este trabalho centrou-se em dois métodos relacionados com sistemas complexos, como sistemas dinâmicos de tempo discreto, redes complexas, autômatos celulares (AC) e suas combinações. O primeiro método foi explorar as propriedades das profundezas do caos como fonte de pseudo-aleatoriedade a partir de sistemas dinâmicos caóticos, como o mapa logístico e o mapa da tenda. Observamos que os padrões desaparecem e a pseudo-aleatoriedade é aumentada pela remoção de k dígitos à direita da vírgula dos pontos de uma órbita original de um mapa caótico. Portanto, foi encontrada uma fonte caótica interessante para obter geradores de números de pseudo-aleatórios (PRNGs) parametrizada por k. Um segundo método foi proposto com base na incorporação de autômatos celulares na topologia de rede, também chamada de rede-autômato, visando caracterizar as redes a partir da dinâmica espaço-temporal intrínseca dessas redes. Quatro problemas de grande demanda foram explorados, tais como (i) identificar redes sociais online; (ii) identificar organismos de diferentes domínios da vida através de suas redes metabólicas; (iii) classificar padrões de distribuição de estômatos variando de acordo com diferentes condições ambientais; e (iv) o problema de identificação de autoria. Finalmente, essa mesma abordagem foi utilizada para analisar as sequências de números pseudo-aleatórios gerados pelo padrão ouro do k-mapa logístico no contexto do reconhecimento de padrões. A abordagem proposta permitiu explorar padrões e pseudoaleatoriedade extraídos de uma miríade de sistemas com resultados bem-sucedidos em termos de acerto e boa pseudo-aleatoriedade. Além disso, este trabalho trouxe consigo progressos significativos em aplicações de reconhecimento de padrões do mundo real de um amplo ramo de campos como criptografia, criptoanálise, biologia e ciência dos dados. / In this work, we demonstrate that patterns and randomness are close related, contrary to what intuitively is considered as opposite fields. We aimed for a pattern recognition approach that aims for two purposes: (i) to take advantages from the chaotic properties as a source of pseudo-randomness in order to measure pseudo-randomness and (ii) to extract patterns from spatio-temporal diagrams obtained from complex systems models as a pattern recognition method. This work has focused on different complex systems such as discrete dynamical systems, complex networks, cellular automata (CA), and their combinations. The first method was to explore the chaotic properties in a deep-zoom manner as a source of pseudo-randomness from chaotic dynamical systems such as the logistic map and the tent map. We observed that the patterns vanish and therefore pseudo-randomness is increased by removing k right digits from the original orbit sequences. Therefore, we found an interesting chaotic source to obtain pseudo-randomness number generators (PRNGs). A second method was proposed based on the embedding of cellular automata (CA) over a network topology, also called network automata, aiming to characterize networks from the intrinsic spatio-temporal dynamics of these networks. Various on-demand problems were explored such as (i) identifying online social networks; (ii) identifying organisms from distinct domains of life through their metabolic networks; (iii) classifying stomata distribution patterns varying according to different environmental conditions; and (iv) the authorship identification problem. Finally, this same approach was used to analyze the sequences of pseudo-random numbers generated by the gold standard k-logistic map in the context of pattern recognition. So far, the proposed pattern recognition approach based on non-linear systems allowed us to explored patterns and pseudo-randomness extracted from a myriad of systems with successful results in terms of accuracy and good pseudorandomness. The proposed method has made significant progress in real-world pattern recognition applications from a wide branch of fields such as Cryptography, Cryptanalysis, Biology and Data Science.
63

Models of complexity in Robert Coover's John's wife and the adventures of Lucky Pierre

Bem, Isabella Vieira de January 2005 (has links)
Esta tese de doutorado analisa dois romances do escritor Norte-Americano Robert Coover como exemplos de escrita hipertextual e de hiperficção no suporte do livro de papel. A complexidade dos romances John's Wife e The Adventures of Lucky Pierre integra os elementos culturais característicos da atual fase do capitalismo e as práticas tecnologizadas que vêm forjando uma subjetividade diferente na escrita e leitura hipertextual, a subjetividade pós-humana. Os modelos da complexidade dos romances derivam do conceito de atratores estranhos da Teoria do Caos e de rizoma da Nomadologia. As transformações no grau de corporeidade dos personagens estabelecem o plano em que se discute a turbulência e a pós-humanidade. As noções de padrões dinâmicos e atratores estranhos e os conceitos do Corpo sem Órgãos e do Rizoma são interpretados para se revisar a narratologia e chegar a categorias apropriadas ao estudo dos romances. A leitura exercitada nesta tese põe em prática a proposta de leitura corpórea de Daniel Punday. As mudanças no grau de materialidade dos personagens são associadas aos estágios de ordem, turbulência e caos na estória, agindo sobre a constituição da subjetividade ao longo do processo de leitura. A inscrição dos planos de consistência que Coover realiza para se contrapor à linearidade e acomodar as feições hipertextuais nas narrativas em papel descreve a trajetória rizomática dos personagens. O presente estudo leva a concluir que a narrativa hoje se constitui antes como um regime numa relação rizomática com outros regimes na prática cultural do que como forma e gênero predominantemente literários. Também se conclui que a subjetividade pós-humana emerge alinhada a uma identidade de classe que tem nos romances hipertextuais a sua forma literária predileta. / This doctoral dissertation analyzes two novels by the American novelist Robert Coover as examples of hypertextual writing on the book bound page, as tokens of hyperfiction. The complexity displayed in the novels, John's Wife and The Adventures of Lucky Pierre, integrates the cultural elements that characterize the contemporary condition of capitalism and technologized practices that have fostered a different subjectivity evidenced in hypertextual writing and reading, the posthuman subjectivity. The models that account for the complexity of each novel are drawn from the concept of strange attractors in Chaos Theory and from the concept of rhizome in Nomadology. The transformations the characters undergo in the degree of their corporeality sets the plane on which to discuss turbulence and posthumanity. The notions of dynamic patterns and strange attractors, along with the concept of the Body without Organs and Rhizome are interpreted, leading to the revision of narratology and to analytical categories appropriate to the study of the novels. The reading exercised throughout this dissertation enacts Daniel Punday's corporeal reading. The changes in the characters' degree of materiality are associated with the stages of order, turbulence and chaos in the story, bearing on the constitution of subjectivity within and along the reading process. Coover's inscription of planes of consistency to counter linearity and accommodate hypertextual features to the paper supported narratives describes the characters' trajectory as rhizomatic. The study led to the conclusion that narrative today stands more as a regime in a rhizomatic relation with other regimes in cultural practice than as an exclusively literary form and genre. Besides this, posthuman subjectivity emerges as class identity, holding hypertextual novels as their literary form of choice.
64

Organização em sistema caótico: uso das tags para classificação da informação pelos usuários da rede social Twitter

Sousa, Amanda Moura de 20 March 2012 (has links)
Made available in DSpace on 2015-10-19T11:50:25Z (GMT). No. of bitstreams: 1 sousa2012.pdf: 3705794 bytes, checksum: 6faef66238e62b646a9ccd8ce1cc6df9 (MD5) Previous issue date: 2012-03-20 / It discusses issues related to classification and knowledge organization, folksonomy, information retrieval and the theories of chaos and complexity in systems, in order to approach the concepts needed to conduct the investigation. Approaches classification since its innate character, through the philosophical studies started in antiquity, even to the scientific approach to design of bibliographic classifications, and the classifications that have been used for organizing information in the Web 2.0 era. The theoretical discussion is developed on the theories of chaos and complexity in systems and their relationship with social networking sites. In particular with the social network Twitter which is a network of messages posted by users of the system, limited to 140 characters, without forming user groups by communities or groups of interest, as it is common in other social networks. The exploratory and empirical research shows the use and purpose of hashtags in Twitter, highlighting the role of collaboration in the choice of terms. Concludes that collaboration is essential to make information retrieval more effective, as well as acting in the convergence of knowledge / Aborda temas relacionados à classificação e organização do conhecimento, folksonomia, recuperação da informação e às teorias do caos e da complexidade em sistemas, com o objetivo de constituir o campo conceitual necessário para conduzir a investigação. Trata a classificação desde o seu caráter inato, passando pelos estudos filosóficos iniciados na antiguidade, chegando até a abordagem científica da concepção das classificações bibliográficas e das classificações que vem sendo utilizadas para a organização da informação na era da Web 2.0. Num segundo momento, a discussão teórica se desenvolve nas teorias do caos e da complexidade em sistemas e suas relações com as redes sociais na Internet, em particular, com a rede social Twitter que é uma rede de mensagens postadas pelos usuários do sistema, limitadas a 140 caracteres, sem o agrupamento dos usuários por comunidades ou grupos de interesse, como é comum em outras redes sociais. A pesquisa exploratória e empírica evidencia o uso e as finalidades das hashtags no Twitter, destacando o papel da colaboração na escolha dos termos. Conclui que a colaboração é essencial para tornar a recuperação da informação mais efetiva, além de atuar na convergência de saberes
65

Aprendizagem da língua inglesa como segunda língua baseada em tarefas: uma proposta de trabalho com ciclo complexo / Learning of english as a second language-based tasks: a job offer with complex cycle

Lopes Júnior, Juarez Aloizio 31 January 2014 (has links)
Submitted by Aline Batista (alinehb.ufpel@gmail.com) on 2015-04-02T19:23:46Z No. of bitstreams: 2 Aprendizagem da língua inglesa como segunda língua baseada em tarefas.pdf: 10361270 bytes, checksum: 50839ecc3d133d5fe19ddf26c6cd568f (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2015-04-03T01:21:36Z (GMT) No. of bitstreams: 2 Aprendizagem da língua inglesa como segunda língua baseada em tarefas.pdf: 10361270 bytes, checksum: 50839ecc3d133d5fe19ddf26c6cd568f (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-04-03T01:23:20Z (GMT). No. of bitstreams: 2 Aprendizagem da língua inglesa como segunda língua baseada em tarefas.pdf: 10361270 bytes, checksum: 50839ecc3d133d5fe19ddf26c6cd568f (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-01-31 / Sem bolsa / Em 1997, a autora Diane Larsen-Freeman publicou um inquietante artigo chamado “Ciência do Caos / Complexidade e Aquisição de Segunda Língua” (LARSENFREEMAN, 1997). Nesse trabalho, a linguista argumenta que há muitas similaridades entre a nova ciência do caos/complexidade e a aquisição de segunda língua. Diante das reflexões que tais ideias suscitam, pretende-se analisar a estrutura e a teoria da aprendizagem baseada em tarefas (Task Based Learning), sob a ótica da teoria do caos/complexidade. De acordo com Willis, J. (1996), essa abordagem comunicativa apresenta seis etapas, a saber: pré-tarefa, tarefa, planejamento, relatório, análise e prática. Como recorte em um universo tão amplo de pesquisa, tem-se a relação da teoria do caos/complexidade com o ciclo da tarefa – tarefa, planejamento e relatório (task-planning-report), enunciado por Willis, J. (1996).De acordo com Larsen-Freeman e Cameron (2008), uma abordagem complexa não se traduz em um método de ensino de L2 complexo. Este trabalho visa aproximar o trabalho seminal da linguista Diane Larsen-Freeman sobre a Teoria do Caos/Complexidade e Aquisição de Segunda Língua (1997) com a Aprendizagem Baseada em Tarefas propostanove anos antes por Willis, J. e Willis, D. (1988). Esta dissertação de mestrado concluiu que o ciclo da tarefa pode ser caracterizado como um sistema adaptativo complexo, uma vez que satisfaz suas regras de baixo nível, já que se trata de um sistema que é dinâmico, complexo, não linear, caótico, imprevisível, sensível às condições iniciais, aberto, auto-organizável, sensível ao feedback e adaptável. / In 1997, the linguist Diane Larsen-Freeman published a disturbing article called “Chaos/Complexity Science and Second Language Acquisition”(LARSENFREEMAN, 1997). In this article, the author states that there are many similarities between the new science of chaos/complexity and second language acquisition. Faced with the reflections, which give rise to such ideas, one intends to analyse the structure and theory of Task Based Learning under the light of the Chaos/Complexity Theory. According to Willis, J. (1996), this communicative approach presents itself with six stages, namely: pre-task, task, planning, report, analyses and practice. As part of a so vast research area, one intends to relate the Chaos/Complexity Theory with the task cycle – task, planning and report – formulated by Willis, J. (1996). According to Larsen-Freeman and Cameron (2008), a complexity approach does not translate into a complexity method for teaching language. This work aims to approximate the seminal article by Diane Larsen-Freeman about the Chaos/Complexity Theory and Second Language Acquisition (1997) with Task Based Learning proposed nine years before by Willis, J. and Willis, D. (1988).To sum up, this dissertation aims to show that the task cycle may be characterized as a complex adaptive system, once it complies with the rules of such systems, that is, dynamic, complex, nonlinear, chaotic, unpredictable, sensitive to the initial conditions, open, self-organizing, feedback sensitive and adaptive.
66

Determining originality in creative literary works

Geyer, Sunelle 14 June 2006 (has links)
Originality is the most basic requirement for the copyrighting of a work and may be viewed as the mirror image of copyright infringement. In terms of section 2(3) of the Copyright Act, a work remains eligible for copyright even if the making thereof involved an infringement of copyright in some other work. However, a certain aspect or a feature of a work (relating to the “substantial part” requirement for copyright infringement; “substantial part” being understood from a hypertext rather than a linear point of view) cannot be infringing and original. In this thesis, the South African legal understanding of the originality concept is determined from case law. Specific attention is given to the meaning of “skill” and “labour”; the protection afforded to mere labour in South Africa and certain selected other jurisdictions; how the subjective nature of the originality test is affected by the “meritorious distinctiveness” requirement; and the degree of own skill and/or labour required for a work to be original and consequently protected. The present literary concept of originality is derived from literary discussions that appeared in newspapers and other publications in the wake of six “plagiarism scandals” which each caused a furore in Afrikaans literary circles. Even though the terminology used by littérateurs differs from that used in legal circles, originality essentially means the same for littérateurs and lawyers. Skill and/or labour as required by law is reflected in the literary “crucial distance” concept. The fact that a sufficient degree of skill and/or labour is required is reflected in the fact that the literary standard of a work is determined on the basis of how “tightly woven” a work is. Although a general protection of original ideas would negatively influence the free flow of information, measures for the protection of ideas are developing, particularly in the United States of America, where ideas (especially in the film industry) are a very valuable commodity. As Swarth proposes, applying the “novelty” and “concreteness” criteria in inverse ratio to each other could help to create an environment where idea purveyors and prospective buyers felt more free to negotiate and enter into agreements over original ideas. Postmodernism, a contemporary interpretative strategy that reaches into nearly every aspect of modern society, is discussed with specific reference to its interaction with originality. The influences of two phenomena of postmodernism on the originality concept, namely hypertext and Chaos theory, are investigated. Recommendations are made regarding measures aimed at the retention of talented authors and the original content of works in the wake of plagiarism scandals, while still holding the wrongdoer responsible for his actions. Certain suggestions are also made regarding the accessibility of courts and the supplementation of the few available precedents regarding originality in creative literary works. / Thesis (LLD)--University of Pretoria, 2007. / Private Law / unrestricted
67

Hydroclimatological Modeling Using Data Mining And Chaos Theory

Dhanya, C T 08 1900 (has links) (PDF)
The land–atmosphere interactions and the coupling between climate and land surface hydrological processes are gaining interest in the recent past. The increased knowledge in hydro climatology and the global hydrological cycle, with terrestrial and atmospheric feedbacks, led to the utilization of the climate variables and atmospheric tele-connections in modeling the hydrological processes like rainfall and runoff. Numerous statistical and dynamical models employing different combinations of predictor variables and mathematical equations have been developed on this aspect. The relevance of predictor variables is usually measured through the observed linear correlation between the predictor and the predictand. However, many predictor climatic variables are found to have been switching the relationships over time, which demands a replacement of these variables. The unsatisfactory performance of both the statistical and dynamical models demands a more authentic method for assessing the dependency between the climatic variables and hydrologic processes by taking into account the nonlinear causal relationships and the instability due to these nonlinear interactions. The most obvious cause for limited predictability in even a perfect model with high resolution observations is the nonlinearity of the hydrological systems [Bloschl and Zehe, 2005]. This is mainly due to the chaotic nature of the weather and its sensitiveness to initial conditions [Lorenz, 1963], which restricts the predictability of day-to-day weather to only a few days or weeks. The present thesis deals with developing association rules to extract the causal relationships between the climatic variables and rainfall and to unearth the frequent predictor patterns that precede the extreme episodes of rainfall using a time series data mining algorithm. The inherent nonlinearity and uncertainty due to the chaotic nature of hydrologic processes (rainfall and runoff) is modeled through a nonlinear prediction method. Methodologies are developed to increase the predictability and reduce the predictive uncertainty of chaotic hydrologic series. A data mining algorithm making use of the concepts of minimal occurrences with constraints and time lags is used to discover association rules between extreme rainfall events and climatic indices. The algorithm considers only the extreme events as the target episodes (consequents) by separating these from the normal episodes, which are quite frequent and finds the time-lagged relationships with the climatic indices, which are treated as the antecedents. Association rules are generated for all the five homogenous regions of India (as defined by Indian Institute of Tropical Meteorology) and also for All India by making use of the data from 1960-1982. The analysis of the rules shows that strong relationships exist between the extreme rainfall events and the climatic indices chosen, i.e., Darwin Sea Level Pressure (DSLP), North Atlantic Oscillation (NAO), Nino 3.4 and Sea Surface Temperature (SST) values. Validation of the rules using data for the period 1983-2005, clearly shows that most of the rules are repeating and for some rules, even if they are not exactly the same, the combinations of the indices mentioned in these rules are the same during validation period with slight variations in the representative classes taken by the indices. The significance of treating rainfall as a chaotic system instead of a stochastic system for a better understanding of the underlying dynamics has been taken up by various studies recently. However, an important limitation of all these approaches is the dependence on a single method for identifying the chaotic nature and the parameters involved. In the present study, an attempt is made to identify chaos using various techniques and the behaviour of daily rainfall series in different regions. Daily rainfall data of three regions with contrasting characteristics (mainly in the spatial area covered), Malaprabha river basin, Mahanadi river basin and All India for the period 1955 to 2000 are used for the study. Auto-correlation and mutual information methods are used to determine the delay time for the phase space reconstruction. Optimum embedding dimension is determined using correlation dimension, false nearest neighbour algorithm and also nonlinear prediction methods. The low embedding dimensions obtained from these methods indicate the existence of low dimensional chaos in the three rainfall series considered. Correlation dimension method is repeated on the phase randomized and first derivative of the data series to check the existence of any pseudo low-dimensional chaos [Osborne and Provenzale, 1989]. Positive Lyapunov exponents obtained prove the exponential divergence of the trajectories and hence the unpredictability. Surrogate data test is also done to further confirm the nonlinear structure of the rainfall series. A limit in predictability in chaotic system arises mainly due to its sensitivity to the infinitesimal changes in its initial conditions and also due to the ineffectiveness of the model to reveal the underlying dynamics of the system. In the present study, an attempt is made to quantify these uncertainties involved and thereby improve the predictability by adopting a nonlinear ensemble prediction. A range of plausible parameters is used for generating an ensemble of predictions of rainfall for each year separately for the period 1996 to 2000 using the data till the preceding year. For analyzing the sensitiveness to initial conditions, predictions are made from two different months in a year viz., from the beginning of January and June. The reasonably good predictions obtained indicate the efficiency of the nonlinear prediction method for predicting the rainfall series. Also, the rank probability skill score and the rank histograms show that the ensembles generated are reliable with a good spread and skill. A comparison of results of the three regions indicates that although they are chaotic in nature, the spatial averaging over a large area can increase the dimension and improve the predictability, thus destroying the chaotic nature. The predictability of the chaotic daily rainfall series is improved by utilizing information from various climatic indices and adopting a multivariate nonlinear ensemble prediction. Daily rainfall data of Malaprabha river basin, India for the period 1955 to 2000 is used for the study. A multivariate phase space is generated, considering a climate data set of 16 variables. The redundancy, if any, of this atmospheric data set is further removed by employing principal component analysis (PCA) method and thereby reducing it to 8 principal components (PCs). This multivariate series (rainfall along with 8 PCs) are found to exhibit a low dimensional chaotic nature with dimension 10. Nonlinear prediction is done using univariate series (rainfall alone) and multivariate series for different combinations of embedding dimensions and delay times. The uncertainty in initial conditions is thus addressed by reconstructing the phase space using different combinations of parameters. The ensembles generated from multivariate predictions are found to be better than those from univariate predictions. The uncertainty in predictions is reduced or in other words, the predictability is improved by adopting multivariate nonlinear ensemble prediction. The restriction on predictability of a chaotic series can thus be reduced by quantifying the uncertainty in the initial conditions and also by including other possible variables, which may influence the system. Even though, the sensitivity to initial conditions limit the predictability in chaotic systems, a prediction algorithm capable of resolving the fine structure of the chaotic attractor can reduce the prediction uncertainty to some extent. All the traditional chaotic prediction methods are based on local models since these methods model the sudden divergence of the trajectories with different local functions. Conceptually, global models are ineffective in modeling the highly unstable structure of the chaotic attractor [Sivakumar et al., 2002a]. This study focuses on combining a local learning wavelet analysis (decomposition) model with a global feedforward neural network model and its implementation on phase space prediction of chaotic streamflow series. The daily streamflow series at Basantpur station in Mahanadi basin, India is found to exhibit a chaotic nature with dimension varying from 5-7. Quantification of uncertainties in future predictions are done by creating an ensemble of predictions with wavelet network using a range of plausible embedding dimension and delay time. Compared with traditional local approximation approach, the total predictive uncertainty in the streamflow is reduced when modeled with wavelet networks for different lead times. Localization property of wavelets, utilizing different dilation and translation parameters, helps in capturing most of the statistical properties of the observed data. The need for bringing together the characteristics of both local and global approaches to model the unstable yet ordered chaotic attractor is clearly demonstrated.
68

Uma abordagem de predição da dinâmica comportamental de processos para prover autonomia a ambientes distribuídos / An approach to provide autonomy to distributed environments by predicting the dynamics of process behavior

Evgueni Dodonov 01 July 2009 (has links)
A evolução de sistemas distribuídos resultou em aumento significativo de complexidade para manutenção e gerenciamento, tornando pouco eficientes técnicas convencionais baseadas em intervenções manuais. Isso motivou pesquisas que deram origem ao paradigma de computação autônoma (Autonomic Computing), que provê aspectos de auto-configuração, auto-recuperação, auto-otimização e auto-proteção a fim de tornar sistemas auto-gerenciáveis. Nesse contexto, esta tese teve como objetivo prover autonomia a ambientes distribuídos, sem a necessidade de mudar o paradigma de programação e as aplicações de usuários. Para isso, propôs-se uma abordagem que emprega técnicas para compreensão e predição de dinâmicas comportamentais de processos, utilizando abordagens de sistemas dinâmicos, inteligência artificial e teoria do caos. Os estudos realizados no decorrer desta pesquisa demonstraram que, ao predizer padrões comportamentais, pode-se otimizar diversos aspectos de computação distribuída, suportando tomadas de decisão autônomas pelos ambientes. Para validar a abordagem proposta, foi desenvolvida uma política de escalonamento distribuído, denominada PredRoute, a qual utiliza o conhecimento sobre o comportamento de processos para otimizar, transparentemente, a alocação de recursos. Experimentos realizados demonstraram que essa política aumenta o desempenho em até 4 ordens de grandeza e apresenta baixo custo computacional, o que permite a sua adoção para escalonamento online de processos / The evolution of distributed systems resulted in a significant growth in management and support complexities, which uncovered the inefficiencies incurred by the usage of conventional management techniques, based in manual interventions. This, therefore, has motivated researches towards the concept of Autonomic Computing, which provides aspects of self-configuration, self-healing, self-optimization and self-protection, aiming at developing computer systems capable of self-management. In this context, this thesis was conceived with the goal of providing autonomy to distributed systems, without changing the programming paradigm or user applications. In order to reach this goal, we proposed an approach which employs techniques capable of modelling and predicting the dynamics of application behavior, using concepts introduced in dynamical systems, artificial intelligence, and chaos theory. The obtained results demonstrated that it is possible to optimize several aspects of distributed computing, providing support for autonomic computing capabilities to distributed environments. In order to validate the proposed approach, a distributed scheduling policy was developed, named PredRoute, which uses the knowledge about the process behavior to transparently optimize the resource allocation. Experimental results demonstrated that this policy can improve the system performance by up to a power of 4, and also requires a considerably low computational cost, which suggests its adoption for online process scheduling in distributed environments
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The Heidegger Collection

Lin, Tung-Lung 08 1900 (has links)
The dissertation consists of two parts: (1) the essay and (2) the composition. The essay elucidates the composer's creative process of the orchestral works, The Heidegger Collection. The Heidegger Collection has five movements. The titles of each movement are derived from the key philosophical concepts from Heidegger's most significant writing, Being and Time: (1) State-of-Mind, (2) Idle-Talk, (3) Moment-of-Vision, (4) Dread, and (5) Being-towards-the-End. The essay discusses the meanings of the five concepts, and explains how I express my reaction to Heidegger's thinking through music composition. The essay also discusses the essential musical language of The Heidegger Collection, such as interval cycles, polyrhythmic patterns, algorithmic elements, portamento effects, chaos theory, and oriental influence.
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Providence and Space-Time: Rethinking God's Relation to the World Through the Eyes of John Polkinghorne

Birch, John F. January 2020 (has links)
No description available.

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