abstract: Recent efforts in data cleaning have focused mostly on problems like data deduplication, record matching, and data standardization; few of these focus on fixing incorrect attribute values in tuples. Correcting values in tuples is typically performed by a minimum cost repair of tuples that violate static constraints like CFDs (which have to be provided by domain experts, or learned from a clean sample of the database). In this thesis, I provide a method for correcting individual attribute values in a structured database using a Bayesian generative model and a statistical error model learned from the noisy database directly. I thus avoid the necessity for a domain expert or master data. I also show how to efficiently perform consistent query answering using this model over a dirty database, in case write permissions to the database are unavailable. A Map-Reduce architecture to perform this computation in a distributed manner is also shown. I evaluate these methods over both synthetic and real data. / Dissertation/Thesis / Doctoral Dissertation Computer Science 2014

Na área de simulação de processos, existe uma visível tendência da migração das ferramentas seqüenciais modulares, que hoje são as mais amplamente utilizadas, para as baseadas em equações. Uma das principais vantagens do paradigma baseado em equações ou simultâneo é que este se mostra eficiente na solução de problemas de simulação, otimização, estimação de parâmetros e reconciliação de dados, todos baseados em um mesmo conjunto de modelos, evitando retrabalho de modelagem. Porém, a tecnologia simultânea também apresenta algumas deficiências, onde destacam-se os problemas de robustez tanto na modelagem quanto na obtenção de resultados numéricos. Este trabalho tem como objetivo reunir e desenvolver técnicas que permitam reduzir estas deficiências. Para tanto, as técnicas conhecidas para depuração de sistemas de equações que representam problemas estacionários e dinâmicos foram estudadas em detalhe. Pôde-se observar que para o caso estático os métodos disponíveis para depuração de modelos, já se apresentam em um nível bem desenvolvido. Já para o caso dinâmico, onde há uma maior complexidade, as técnicas conhecidas encontram-se em um nível de desenvolvimento muito menor. Neste ponto encontram-se as principais contribuições deste trabalho. / In the field of process simulation the movement from the sequential modular tools, which are currently the most widely used, to the equation based approach is clear. One of the key advantages of the equation based or simulatneous approach is that using a single model one can solve simulation, optimization, parameter estimation, and optimization problems. This fact avoids modeling rework for each application. However, the simultaneous technology has problems regarding modeling and solving robustness. This work aims to group and develop methods capable of minimize these deficiencies. In order to achieve this goal, available debugging approaches for both steady-state and dynamic system of equations were studied in detail. For the steady-state case well stablished debugging techniques are known. For dynamic models, where the complexity is higher, the analysis and debugging methods are much less mature. This was the source for the major contributions of this work.

O gás de Bose carregado foi estudado em duas e três dimensões, sendo que no caso bidimensional foram considerados dois tipos distintos de interação: l/r e ln(r). Aplicamos a esses sistemas o método do campo auto-consistente que leva em consideração a interação de curto alcance entre os bosons através de uma correção de campo local. Por meio de cálculos numéricos auto-consistentes determinamos o fator de estrutura S(&#8594k) em um amplo intervalo de densidades. A partir de S(&#8594k) obtivemos a função de correlação dos pares, a energia do estado fundamental que é essencialmente a energia de correlação, a pressão do gás e o espectro de excitações elementares. Calculamos ainda a densidade de blindagem induzida por uma impureza carregada fixada no gás. No limite de altas densidades nossos cálculos reproduzem os resultados da teoria de perturbação de Bogoliubov. Na região de densidades intermediárias em que os sistemas são fortemente correlacionados nossos resultados apresentam uma boa concordância com cálculos baseados na aproximação de HNC e no método de Monte Carlo. Nossos resultados são em várias situações confrontados com os de RPA demonstrando que o método que utilizamos é muito mais adequado para tratar o sistema. Os sistemas bidimensionais mostraram-se mais correlacionados que o tridimensional, sendo que o gás com interação l/r é mais correlacionado que o logarítmico a altas densidades, mas na região de densidades baixas essa situação se inverte. Finalmente calculamos as funções termodinâmicas dos sistemas bi e tridimensionais a temperaturas finitas próximas do zero absoluto baseando-nos nos espectros de excitação do gás a temperatura zero. / The two and three-dimensional charged Bose gas have been studied. In the bidimensional case two different types of interaction were considered: l/r and ln(r).We have applied to these systems the self-consistent-field method, which takes into account the short range correlations between the bosons through a local-field correction. By using self-consistent numerical calculations we determinate the structure factor S(&#8594k) in a wide range of densities. From S(&#8594k) we obtained the pair-correlation function, the ground-state energy, the pressure of the gas and the spectrum of elementary excitations. In addition we calculated the screening density induced by a fixed charged impurity. In the high-density limit our calculations reproduce the results given by Bogoliubov\'s perturbation theory. In the intermediate-density region, corresponding to the strongly coupled systems, our results are in very good agreement with calculations based on HNC approximation as well as Monte Carlo method. Our results are compared in several situations with RPA results showing that the self-consistent method is much more accurate. The two-dimensional systems showed to be more correlated than the three-dimensional one; the gas with interaction l/r is also more correlated than the logarithmic one at high densities, but it begins to be less correlated than this one in the low-density region. Finally we calculated the thermodynamic functions of the two and three-dimensional systems at finite temperatures near absolute zero, based upon the gas excitation spectra at zero temperature.

Na área de simulação de processos, existe uma visível tendência da migração das ferramentas seqüenciais modulares, que hoje são as mais amplamente utilizadas, para as baseadas em equações. Uma das principais vantagens do paradigma baseado em equações ou simultâneo é que este se mostra eficiente na solução de problemas de simulação, otimização, estimação de parâmetros e reconciliação de dados, todos baseados em um mesmo conjunto de modelos, evitando retrabalho de modelagem. Porém, a tecnologia simultânea também apresenta algumas deficiências, onde destacam-se os problemas de robustez tanto na modelagem quanto na obtenção de resultados numéricos. Este trabalho tem como objetivo reunir e desenvolver técnicas que permitam reduzir estas deficiências. Para tanto, as técnicas conhecidas para depuração de sistemas de equações que representam problemas estacionários e dinâmicos foram estudadas em detalhe. Pôde-se observar que para o caso estático os métodos disponíveis para depuração de modelos, já se apresentam em um nível bem desenvolvido. Já para o caso dinâmico, onde há uma maior complexidade, as técnicas conhecidas encontram-se em um nível de desenvolvimento muito menor. Neste ponto encontram-se as principais contribuições deste trabalho. / In the field of process simulation the movement from the sequential modular tools, which are currently the most widely used, to the equation based approach is clear. One of the key advantages of the equation based or simulatneous approach is that using a single model one can solve simulation, optimization, parameter estimation, and optimization problems. This fact avoids modeling rework for each application. However, the simultaneous technology has problems regarding modeling and solving robustness. This work aims to group and develop methods capable of minimize these deficiencies. In order to achieve this goal, available debugging approaches for both steady-state and dynamic system of equations were studied in detail. For the steady-state case well stablished debugging techniques are known. For dynamic models, where the complexity is higher, the analysis and debugging methods are much less mature. This was the source for the major contributions of this work.

Submitted by Jaqueline Silva (jtas29@gmail.com) on 2016-12-14T19:00:27Z No. of bitstreams: 2 Dissertação - Gabriela de Araújo Achegaua Salazar - 2016.pdf: 1867612 bytes, checksum: 2444ce3444e2753459478adf4d25d865 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Jaqueline Silva (jtas29@gmail.com) on 2016-12-14T19:00:50Z (GMT) No. of bitstreams: 2 Dissertação - Gabriela de Araújo Achegaua Salazar - 2016.pdf: 1867612 bytes, checksum: 2444ce3444e2753459478adf4d25d865 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-12-14T19:00:50Z (GMT). No. of bitstreams: 2 Dissertação - Gabriela de Araújo Achegaua Salazar - 2016.pdf: 1867612 bytes, checksum: 2444ce3444e2753459478adf4d25d865 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-11-16 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / This paper is a analysis about the academic research done in 2001 – 2012 periods in the postgraduate programs in Education and Education in Science and Mathematics on the teacher who teaches mathematics. The main goal of this paper was analyze and understand the academic literature on the teacher who teaches mathematics from a theoretical and methodological perspective to answer the following research question: Research has as subject to the teacher teaching math presented incoherence of cleat theoretical-methodological? It was used the meta-analysis like a kind of bibliographyc research like methodology. The theoretical framework is grounded in the activity’s theory of Leontiev which has theoretical and methodological bases grounded in Marxist thought. The main conception of research to investigate human phenomena was based on Vigotski who emphasizes the importance of considering the historicity of the phenomenon to explain the relationships that make up the whole. It was necessary to understand the evolution of research in Humanities (ALVES-MAZZOTTI; GEWAMDSZNADJDER, 1998; LAVILLE; DIONNE, 1999) and consequently in Education (GATTI, 2002) to understand the research in Mathematics Education in Brazil (FIORENTINI, 1994; FIORENTINI; LORENZATO, 2009). The problems encountered in educational research were treated based on Gatti (1983, 2002), Gouveia (1971), Souza, Magalhães and Silveira (2014) followed by the problems in Mathematics Education production (BICUDO, 1993; BICUDO; PAULO, 2011; FIORENTINI; LORENZATO, 2009). It was recorded 20 papers that studied the teacher who teaches mathematics, however, only those who presented the teacher as the subject of the research were analyzed. It was established as categories of analysis Coherence between problem and problematic, Theoretical-methodological Coherence and Coherence between problem, theoretical referential and methodology, in which 8 papers were analyzed in the postgraduate programs already mentioned. The main conclusions was that the majority of the academic works that has as focus of analysis the teacher who teaches mathematics presents theoretical and methodological. / Este estudo analisa a produção acadêmica realizada no período de 2001 a 2012 nos programas de Pós-Graduação das áreas de Educação e de Ensino de Goiás sobre o professor que ensina matemática. O principal objetivo foi analisar e compreender, a partir de uma perspectiva teórico-metodológica, a produção acadêmica sobre o professor que ensina matemática, para responder a seguinte questão de pesquisa: As pesquisas que têm como tema o professor que ensina matemática apresentam incoêrencias de cunho teórico- metodológico? Utilizou-se a pesquisa bibliográfica do tipo meta-análise como metodologia. O referencial teórico é pautado na teoria da atividade de Leontiev, que possui bases teóricas-metodológicas pautadas no pensamento marxista. Tomou-se como principal concepção de pesquisa aquela apresentada por Vigotski, que ressalta a importância de considerar a historicidade do fenômeno para se explicar as relações existentes que formam o todo, ao investigar os fenômenos humanos. Fez-se necessária a compreensão da evolução da pesquisa em Ciências Humanas (ALVES-MAZZOTTI; GEWAMDSZNADJDER, 1998; LAVILLE; DIONNE, 1999) e em Educação (GATTI, 2002) para que se pudesse compreender a pesquisa em Educação Matemática no Brasil (FIORENTINI, 1994; FIORENTINI; LORENZATO, 2009). Os problemas encontrados na pesquisa em Educação foram tratados com base em Gatti (1983, 2002), Gouveia (1971), Souza, Magalhães e Silveira (2014), seguido dos problemas na produção em Educação Matemática (BICUDO, 1993; BICUDO; PAULO, 2011; FIORENTINI; LORENZATO, 2009). Foram fichados 20 trabalhos que de alguma forma estudaram o professor que ensina matemática, porém, foram analisados apenas aqueles apresentavam o professor como sujeito da pesquisa. Estabeleceu-se como categorias de análise Coerência entre problema e problemática, Coerência teórico-metodológica e Coerência entre problema, referencial teórico e metodologia, em que se analisou 8 trabalhos realizados nos programas de pós-graduação já citados. Como principais conclusões, observou-se que a maioria dos trabalhos acadêmicos que tem como foco de análise o professor que ensina matemática apresenta coerência teórico-metodológica.

Dans cette thèse, nous présentons des avancements récents en Théorie des Champs Doubles (TCD) et Théories des Champs Exceptionnels (TCE). Ces théories ont la particularité d’être des reformulations de supergravité dans lesquelles les symétries de dualité sont explicites avant toute réduction dimensionnelle. Ces reformulations se basent sur la définition d’un espace-temps étendu qui géométrise le groupe de T-dualité en TCD et les groupes exceptionnels de U-dualité en TCE. Tous les champs de cet espace sont soumis à une contrainte de section qui restreint leur dépendance en coordonnées. Il existe plusieurs solutions à la contrainte de section, qui correspondent donc à des théories différentes. Dans ce sens, le formalisme des théories des champs étendues amène à une unification de ces théories. De plus, grâce à un outil spécifique aux théories des champs étendues, l’ansatz de Scherk-Schwarz généralisé, il est possible de réécrire les ansatz compliqué de type Kaluza-Klein en supergravité sous une forme élégante et compacte: un produit matriciel en dimensions supérieures. Ici, nous présentons plusieurs exemples de l’efficacité de l’ansatz de Scherk-Schwarz généralisé. En particulier, nous prouvons deux conjectures concernant les troncations cohérentes: la réduction dite “de Pauli” de la corde bosonique ainsi que la supergravité de type IIB sur AdS5 x S5. La dernière application de cet ansatz concerne la théorie de type IIB généralisée, apparue récemment dans l’étude des système intégrables, et son plongement dans la TCE E6(6). Enfin, nous présentons la complétion supersymétrique de la TCE E8(8) bosonique. / In this thesis, recent developments in Double Field Theory (DFT) and Exceptional Field Theory (EFT) are presented. They are reformulation of supergravity in which duality symmetries are made manifest before dimensional reduction. This is achieved through the definition of an extended spacetime that “geometrises” the T-duality group O(d,d) in DFT and exceptional U-duality groups in EFT. All functions on this extended space are subject to a covariant `section constraint', whose solutions then restrict the coordinates dependency of the fields. There exist different solutions to the section constraint that correspond to different theories. In this sense, different theories are unified within the formalism of extended field theories. Moreover, extended field theories possess a powerful tool to study compactifications: the generalised Scherk-Schwarz ansatz.Here, we present several examples of the effectiveness of the generalised Scherk-Schwarz ansatz. In particular, we proved two conjectures regarding consistent truncations: the so-called Pauli reduction of the bosonic string on group manifolds and type IIB supergravity on AdS5 x S5. Another application is presented on the embedding of generalised type IIB within the E6(6) EFT, which recently appeared in the study of integrable systems.Finally, we present the supersymmetric completion of the bosonic E8(8) EFT.

No description available.

Employing correlation consistent basis sets coupled with electronic structure methods has enabled accurate predictions of chemical properties for second- and third-row main group and transition metal molecular species. For third-row (Ga-Kr) molecules, the performance of the correlation consistent basis sets (cc-pVnZ, n=D, T, Q, 5) for computing energetic (e.g., atomization energies, ionization energies, electron and proton affinities) and structural properties using the ab initio coupled cluster method including single, double, and quasiperturbative triple excitations [CCSD(T)] and the B3LYP density functional method was examined. The impact of relativistic corrections on these molecular properties was determined utilizing the Douglas-Kroll (cc-pVnZ-DK) and pseudopotential (cc-pVnZ-PP) forms of the correlation consistent basis sets. This work was extended to the characterization of molecular properties of novel chemically bonded krypton species, including HKrCl, FKrCF3, FKrSiF3, FKrGeF3, FKrCCF, and FKrCCKrF, and provided the first evidence of krypton bonding to germanium and the first di-krypton system. For second-row (Al-Ar) species, the construction of the core-valence correlation consistent basis sets, cc-pCVnZ was reexamined, and a revised series, cc-pCV(n+d)Z, was developed as a complement to the augmented tight-d valence series, cc-pV(n+d)Z. Benchmark calculations were performed to show the utility of these new sets for second-row species. Finally, the correlation consistent basis sets were used to study the structural and spectroscopic properties of Au(CO)Cl, providing conclusive evidence that luminescence in the solid-state can be attributed to oligomeric species rather than to the monomer.

This dissertation sets out to describe a set of financial instruments whose cash flows are driven by the movements in some underlying population's mortality rates. For example, a longevity bond where the coupons are determined with reference to the proportion of the initial population that are alive at the coupon date. Other examples include mortality swaps and mortality swaptions which are analogous to interest rate swaps and interest rate swaptions. It also aims to show there are risks associated with mortality and that these mortality driven instruments can be used to manage some of these risks. These instruments should also enable portfolios that replicate mortality driven cash ows to be constructed. This would in turn allow the market consistent valuation of these cash flows. To construct a pricing framework for these mortality based instruments a stochastic mortality model is needed. In this dissertation the stochastic mortality model used was the Lee-Carter model. The Lee-Carter model in essence models mortality rates per age by calendar year or cohort year using Time Series techniques. Copyright / Dissertation (MSc)--University of Pretoria, 2012. / Mathematics and Applied Mathematics / unrestricted

abstract: The quest to find efficient algorithms to numerically solve differential equations isubiquitous in all branches of computational science. A natural approach to address this problem is to try all possible algorithms to solve the differential equation and choose the one that is satisfactory to one's needs. However, the vast variety of algorithms in place makes this an extremely time consuming task. Additionally, even after choosing the algorithm to be used, the style of programming is not guaranteed to result in the most efficient algorithm. This thesis attempts to address the same problem but pertinent to the field of computational nanoelectronics, by using PETSc linear solver and SLEPc eigenvalue solver packages to efficiently solve Schrödinger and Poisson equations self-consistently. In this work, quasi 1D nanowire fabricated in the GaN material system is considered as a prototypical example. Special attention is placed on the proper description of the heterostructure device, the polarization charges and accurate treatment of the free surfaces. Simulation results are presented for the conduction band profiles, the electron density and the energy eigenvalues/eigenvectors of the occupied sub-bands for this quasi 1D nanowire. The simulation results suggest that the solver is very efficient and can be successfully used for the analysis of any device with two dimensional confinement. The tool is ported on www.nanoHUB.org and as such is freely available. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2020