• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 227
  • 119
  • 49
  • 25
  • 19
  • 17
  • 15
  • 15
  • 8
  • 6
  • 6
  • 4
  • 4
  • 3
  • 3
  • Tagged with
  • 617
  • 175
  • 145
  • 77
  • 76
  • 67
  • 56
  • 50
  • 47
  • 46
  • 45
  • 43
  • 43
  • 42
  • 41
  • 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.
151

Residual-based shadings for visualizing (conditional) independence

Zeileis, Achim, Meyer, David, Hornik, Kurt January 2005 (has links) (PDF)
Residual-based shadings for enhancing mosaic and association plots to visualize independence models for contingency tables are extended in two directions: (a) perceptually uniform HCL colors are used and (b) the result of an associated significance test is coded by the appearance of color in the visualization. For obtaining (a), a general strategy for deriving diverging palettes in the perceptually-based HCL space is suggested. As for (b), cut offs that control the appearance of color are computed in a data-driven way based on the conditional permutation distribution of maximum-type test statistics. The shadings are first established for the case of independence in 2-way tables and then extended to more general independence models for multi-way tables, including in particular conditional independence problems. / Series: Research Report Series / Department of Statistics and Mathematics
152

Služby v obecných souvislostech / Services in mutual contigency

Prouza, Petr January 2010 (has links)
This thesis is focused on services in informatics, especially their global concept and mutual contingency. In this issue there is one main aim but there can be found more minor goals without as high importance as main one. The particular goals are specification of different dimensions of view on informatics services, analysis of standards dealing with services in aim to find mutual contingency, creation of global model of service, definition of global sense and functionality of services and clarifying the look on the services in organizations. If this look is broader one or only technical solution of informatics is taken into account (the broad context is connected with processes and business). In the first part of my thesis the dimensions of different views on issue of services in informatics are specified. It includes the overlapping of these dimensions according to read literature and other internet sources. The second part of my work is about analyzing of standards in information services provided in services orientated architecture and standards dealing with governance of services in informatics. Next chapter involves the global model of service created on basis of previous analysis and the knowledge from read literature. The fourth chapter is focused on definition of the global sense and functionality of services. The last part of my thesis summarized the most common problems which can occur during introduction of services. The last chapter contains the case study in which the importance of understanding of services in their broad context is mentioned and revealed.
153

Lógica e ontologia: as raízes da contingência em Leibniz / Logic and ontology: the sources of contingency in Leibniz

Faria, Chaianne Maria da Silva 07 February 2019 (has links)
Esta pesquisa tem como núcleo uma investigação das condições que permitiram a Leibniz mobilizar o conceito de análise infinita como solução para o problema posto pela dupla e simultânea afirmação da existência de uma estrutura lógica do mundo, que subjaz a todo acontecimento e a toda substância, e da contingência desses mesmos acontecimentos e das substâncias que os produzem dinamicamente na ordem do tempo. Trata-se, portanto, de discutir e elucidar aquilo que, para o filósofo de Hannover, se constitui como raiz da contingência. Assim, sobre o cerne do problema, materializado nas noções de infinito e de análise infinita, coloca-se ainda, como uma segunda camada da pesquisa, a questão relativa à possibilidade, aberta ou não aos seres racionais criados, de produzirem alguma modificação em sua própria existência, e, mais profundamente, na ordem geral da natureza, pela ação de uma vontade livre. Com efeito, a posição da ideia de análise infinita parece bastar para excluir o princípio de contradição como razão suficiente do mundo e dos fatos que nele têm lugar, mas à primeira vista não é o bastante para assegurar aos seres humanos e a outros agentes racionais finitos que porventura haja a possibilidade real de escolha, donde a fragilidade, ainda persistente, da afirmação da contingência como componente do universo. Daí que um estudo do conceito de vontade em Leibniz se mostre tão necessário como etapa da construção da ideia de contingência quanto uma elucidação da noção de análise infinita. Tal estudo é realizado com base na leitura da correspondência com Clarke e no exame do conceito de leis da natureza, as quais para Leibniz nada mais são que atos da vontade divina. Há, enfim, um último elemento que parece se apresentar como base da contingência na filosofia leibniziana: trata-se da possibilidade de afirmar uma existência infinitesimal das substâncias possíveis, graças à qual é dado às substâncias inteligentes criadas participarem, por atos de vontade, da formação dos eventos que constituem sua realidade e a do conjunto das coisas. Dito isso, a dissertação tem como ordem de temas uma breve apresentação do problema do contingência em Leibniz, e do lugar que ele ocupa no tema mais amplo da liberdade tal como pensada pelo filósofo, seguida por estudo da definição leibniziana de proposição verdadeira que põe o primeiro obstáculo à afirmação da contingência , uma análise das conexões entre esse conceito e a tese das noções individuais completas, o exame do nexo entre essa tese e os conceitos de infinito e de expressão, uma breve elucidação dos princípios de contradição e de razão suficiente, e, por último, um estudo do conceito de vontade em Leibniz e de seus conceitos de possível e existente. / The core to this research is an investigation of the conditions that allowed Leibniz to mobilise the concept of infinite analysis as a solution for the issue posed by the double and simultaneous statement of the existence of a logical structure of the world, subjacent to every event and every substance, and of the contingency of these same events produced dynamically in the order of time by these substances. This dissertation, in that sense, will discuss and elucidate what, for Leibniz, constitutes as the root of contingency. Thus, concerning the centre of the problem materialised in the notions of infinite and infinite analysis, we further place, as a second research layer, the question related to the possibility, be it open or not to created rational beings, to produce any modification in the order of their own existences, and, plunging even deeper, in existing natural order, by act of free will. In effect, the position of the idea of infinite analysis seems enough to exclude the principle of contradiction as sufficient reason for the world and for the facts that take place in it, but at a first glance this is not enough to ensure human beings and other created rational agents there might be a real possibility of choice, where the fragility of the statement of contingency as a defining feature of the universe still persists. From there, the study of will in Leibniz presents itself as much necessary as a step for the construction of the concept contingency in the author as it is an elucidation of the notion of infinite analysis. That investigation is here made possible above all based on his correspondence with Clarke, one of the last exchanges of letters in which Leibniz engaged, and in examining the concept of laws of nature, which for Leibniz are acts of the divine will. Lastly, there is one element that presents itself as a base for contingency in Leibnizian Philosophy; that is the possibility of affirming na infinitesimal existence of possible substances, permitting created intelligent substances to participate, by acts of will, in the shaping of events that form their own reality and the universe. That said, the order of themes in this dissertation is as follows: a brief presentation of the problem of contingency in Leibniz, followed by a study around Leibnizian definition of true proposition which establishes the first barrier to the statement of contingency , an analysis of the connections between this concept and the thesis of complete individual notions, the examination of nexus between that thesis and the concepts of infinite and expression, a brief elucidation around the principles of contradiction and sufficient reason, and finally a study of the concept of will in Leibniz and of its concepts of possible and existing.
154

Mutation rates in mycobacterial hosts with altered Dna metabolic activity

Barichievy, Samantha 08 February 2006 (has links)
Master of Science - Molecular Medicine and Haematology / The completion of the genome sequence of Mycobacterium tuberculosis strain H37Rv revealed that 10% of the coding capacity is devoted to two, large multigene families that are characterised by repeat sequences. These are the PE and PPE families that code for acidic, glycine rich proteins. A subgroup of the PE family is the polymorphic GC rich sequence (PGRS) gene subfamily. Genome comparisons of clinical isolates of M. tuberculosis have confirmed the polymorphic character of some of these genes suggesting they may be analogous to the contingency loci found in other pathogenic bacteria. Certain PE-PGRS proteins play a direct role in virulence in M. marinum, other PE-PGRS genes are cell surface associated, and some PE-PGRS proteins are variable surface antigens, supporting a potential role in host pathogen interactions. A reporter assay designed to investigate mutations in a PE-PGRS repeat-containing sequence was used to assess mutation rates in various M. smegmatis host strains by fluctuation analysis. A wide spectrum of mutations was observed and the evidence suggests that slipped-strand mispairing between proximal and distal PGRS sequences located in cis is the predominant type of mutational event at such loci. Moreover, slipped-strand mispairing at such loci occurs at a moderately higher rate than base substitution mutagenesis and is mediated by the normal replicative polymerase.
155

[en] THE CONCEPTION OF CONTINGENCY IN RICHARD RORTY / [pt] A CONCEPÇÃO DE CONTINGÊNCIA EM RICHARD RORTY

FLORA MUNIZ TUCCI DE AZEVEDO 04 September 2007 (has links)
[pt] A dissertação A Concepção de Contingência em Richard Rorty pretende apresentar a concepção de contingência no pensamento de Richard Rorty, que é especialmente desenvolvida em seu livro Contingência, Ironia e Solidariedade (1989). O primeiro capítulo será sobre a contingência da linguagem; o segundo, sobre a contingência do indivíduo, e o terceiro, sobre a contingência de uma comunidade liberal. Partindo desse estudo, o quarto capítulo será constituído pela apresentação de algumas reflexões e críticas em relação à compreensão sobre a contingência, com o objetivo de traçar um diálogo com o autor, buscando trazer maior esclarecimento sobre o tema. As questões estarão relacionadas aos valores defendidos pelo autor em sua comunidade liberal utópica, ao questionar se de fato podem ser deduzidos da sua compreensão de contingência da linguagem e de indivíduo. / [en] The dissertation The conception of contingency in Richard Rorty intends to present the conception of contingency in Richard Rorty's thought, which is especially developed in his book Contingency, Irony and Solidarity (1989). The first chapter will discuss the contingency of language, the second, the contingency of selfhood, and the third, the contingency of a liberal community. From this point, the fourth chapter will comprise the presentation of some reflections and criticisms concerning the comprehension of contingency. Our goal is to outline a discussion with the author to lead to a better understanding on the issue. Thus the questions will be related to the values defended by Rorty in his liberal utopia, and analyze if we can in fact deduce them from the comprehension of contingency of language and selfhood.
156

Contingência e contigüidade no responder de ratos submetidos a esquemas de razão e intervalo variáveis / Contingencies and contiguity imposition on response by exposing rats to variable interval and variable ratio schedule

Fonseca, Cristina Moreira 12 May 2006 (has links)
O presente estudo é formado por dois experimentos (Experimento 1 e Experimento 2) que empregaram procedimento de atraso de reforço não sinalizado non-resetting [esquema tandem em que o segundo componente ocorre em tempo fixo (FT)]. Os experimentos tiveram como objetivo geral manipular experimentalmente relações de contingência e contigüidade utilizando diferentes esquemas de reforço (esquema dependente de resposta, esquema dependente da resposta com liberação atrasada do reforço e esquema independente de resposta). Mais especificamente, os experimentos tiveram como objetivo verificar os efeitos produzidos pela introdução do atraso do reforço sobre a taxa e a distribuição de freqüência no tempo das respostas de pressão à barra, emitidas por ratos submetidos a esquemas de intervalo variável (VI) e razão variável (VR).No Experimento 1, os efeitos da introdução de um atraso de 5 s foram comparados à liberação de água independente da resposta (VT). Os resultados do experimento mostraram que, em linha de base (presença de contingência e contigüidade), o esquema VR gerou, relativamente ao VI, taxas de respostas mais elevadas. Com a introdução do atraso de reforço (presença de contingência e contigüidade reduzida) houve diminuição nas taxas de respostas dos sujeitos de ambos os grupos em relação à linha de base, com diminuição maior nas taxas de respostas dos sujeitos do Grupo VI. Na vigência do VT (ausência de contingência, mas não de contigüidade), esta diminuição foi ainda mais acentuada. Os efeitos diferenciados do atraso nos esquemas VI e VR foram detalhados por meio da distribuição de freqüência de respostas no tempo, de modo a se identificarem os valores de atraso que efetivamente ocorreram (isto é, o intervalo entre a liberação do reforço e a última resposta anteriormente emitida). Para os sujeitos do Grupo VI, os valores de atrasos registrados se concentraram geralmente em valores próximos ao atraso programado de 5 s enquanto que, para os sujeitos do Grupo VR, os intervalos efetivamente registrados assumiram valores menores. Uma explicação para esses resultados deve-se às próprias características dos esquemas. Deste modo, a probabilidade dos atrasos registrados se concentrarem no valor do atraso programado é maior no VI do que no VR. No Experimento 2, foi verificado o efeito da introdução de diferentes valores de atraso - 2, 5 e 8 s - sobre a taxa e a distribuição de freqüência de respostas, submetendo-se ratos ingênuos aos esquemas de VI e VR, com e sem atraso de reforço. Os resultados do Experimento 2 mostraram que, com a introdução dos diferentes valores de atraso de reforço (presença de contingência e contigüidade parametricamente manipulada), houve diminuições nas taxas de respostas dos sujeitos de ambos os grupos. A análise por meio da distribuição de freqüência dos valores de atrasos mostrou que para os sujeitos de ambos os grupos - VI e VR, os valores de atrasos registrados assumiram os menores intervalos quando o atraso foi de 2 s, concentraram-se em valores próximos ao atraso programado, quando o atraso foi de 5 s e, foram distribuídos entre os diferentes intervalos quando o atraso foi de 8 s. Resultados diferentes, porém, foram observados em dois sujeitos cujos valores de atrasos se concentraram nos valores de atrasos programados. No conjunto, os resultados de ambos os experimentos mostram que apesar das taxas de respostas semelhantes, identificam-se efeitos do atraso sob a distribuição do responder quando os sujeitos estão sob VI ou VR. Efeitos que não puderam ser observados quando a análise dos dados limitou-se à taxa de resposta, medida esta mais freqüentemente usada na investigação de relações de contingência e contigüidade. / The present study comprises two experiments (experiment 1 and experiment 2) that applied delayed reinforcement [non-resentting] procedure [schedule in which the second component operates on a fixed time condition (FT)]. The main purpose was to manipulate experimentally contingencies and contiguity relations by using different reinforcement schedules (response dependent schedule, response dependent schedule with delayed reinforcement and response independent schedule). The experiments investigated the effects of delayed reinforcement imposition on the lever press response rate and distribution of frequency on time, by exposing rats to variable interval (VI) and variable ratio schedule (VR). Experiment 1 compared effects of 5 s delays imposition with response independent water presentation. Experiment 1 showed that VR schedule engendered, in baseline condition (contingency and contiguity condition), higher response rates than did VI schedule. Delayed reinforcement (contingency and reduced contiguity condition) produced lower response rates, in both groups, than that of baseline condition. The lowest rates were observed in VI group. During VT condition (no contingency, but with contiguity), the rate decrease was accentuated. The different effects of delay under VI and VR schedules were showed in detail by the distribution of response frequency on time so that the effective delay values could be identified (the interval between reinforcement presentation and the last emitted response). In VI group, the observed delay values were in general near the programmed 5 s delay, whereas the intervals effectively observed, in VR group, were lower than the programmed 5 s delay. The schedules features can explain these results. The observed delays are more likely to be near the delay programmed value in VI than in VR schedule. Experiment 2 showed the effect of imposition of different delay values – 2, 5 and 8 s- on the response rate and frequency distribution, by exposing naïve rats to VI and VR schedules, with and without reinforcement delay. The experiment 2 revealed that the response rates decreased, in both groups, when different reinforcement delay values were presented (contingency and parametrically manipulated contiguity). The analysis of distribution of delay values frequency showed that the registered delay values were lower than the programmed 2 s delay, delay values were in general near the programmed 5 s delay and distributed over the different values in both groups (VI and VR). Different findings were, however, observed in two subjects whose delay values were near the programmed delay values. The results of both experiments, taken together, indicate that the analysis of distribution of delay values frequency reveals the different effects of delay on VI and VR schedule. These effects could not be observed when the data analysis took into account only response rate, a more usual measure employed in investigations on relationship between contingency and contiguity.
157

Estudo de fatores que influenciam a mudança na contabilidade gerencial com enfoque na implementação do balanced scorecard - estudos multicasos / Study of factors that influence the change in the managerial accounting with approach in the implementation of the Balanced Scorecard ? multi-cases study

Silva, Lucileni Pereira da 24 April 2007 (has links)
Nessa pesquisa busca-se identificar se, em empresas em que as variáveis contextuais são mais favoráveis à mudança na contabilidade gerencial, é maior o nível de sofisticação do BSC implementado. Para tanto realizou-se estudos de casos em quatro empresas que implementaram essa ferramenta. Nelas são analisadas as características do BSC implementado e como essas estão associadas a determinadas variáveis contextuais: as características organizacionais e os fatores que aceleram ou desaceleram o processo de mudança na contabilidade gerencial, ambos analisados sob a perspectiva da abordagem contingencial. Embora não seja possível generalizar os resultados, o desenvolvimento do estudo dos casos permitiu confirmar a relação entre tais variáveis contextuais e o nível de sofisticação do BSC implementado nas empresas pesquisadas. Quanto às características organizacionais, observa-se que, de modo geral, conforme crescem o nível de pressão competitiva e o tamanho da empresa, mais sofisticado é o BSC implementado, havendo apenas uma exceção, onde o BSC mais desenvolvido foi explicado por outros fatores. Quanto aos fatores de estímulos para mudanças, três fatores se destacaram, possibilitando relevantes comparações quanto aos tipos de BSC implementados nas empresas: os objetivos específicos para mudança, as necessidades externas e o envolvimento da alta gestão. A análise do grau de comunicação incorporada ao estudo dos casos mostrou que, em empresas onde o BSC é mais desenvolvido, há maior grau de comunicação da estratégia. / This study aims to identify if, in companies where the variable contextual are more favorable to the change in the managerial accounting is higher the level of sophistication of the implemented BSC. Therefore, the studies of cases were done in four companies of which had implemented this tool. In these companies the characteristics of the implemented BSC are analyzed and how these are linked and established to the changeable contextual ones: the organizational characteristics and the factors that speed up or decelerate the process of management accounting change, were both analyzed under the perspective of the contingency approach. Although it is not possible to generalize the results, the development of the study of cases allowed to confirm the relation between such contextual variables and the level of sophistication of the BSC implemented in the studied companies. For the organizational characteristics, it is observed that, in general, as the level of competition and the growth of the company increases, more sophisticated are the implemented BSC. However there is only one exception; the BSC that is more developed was obtained by other factors. In the factors of stimulating changes, three factors stood out, allowing excellent comparisons to the types of BSC implemented in the companies: the specific objectives for change, the external necessities and the engagement of the high level management. The analysis of the degree of communication incorporated to the study of the cases showed that, in companies where the BSC is more developed, it has greater degree of communication of the strategy.
158

A realidade e seus signos: as proposições sobre o futuro contingente e a predestinação divina na lógica de Guilherme de Ockham / The reality and its signs: the propositions about the future contingent and the divine predestination in Guilherme de Ockham\' s logic

Oliveira, Carlos Eduardo de 07 April 2006 (has links)
A \"Exposição de Guilherme de Ockham para o Perihermenias de Aristóteles (i.e., o Sobre a Interpretação)\" traz um problema para \"a verdade os teólogos\": de acordo com Aristóteles, a proposição hipotética que contém um par de contraditórias sobre a mesma coisa futura e contingente não é verdadeira nem falsa de modo determinado - uma vez que nenhuma de suas contraditórias é verdadeira ou falsa de modo determinado. Sendo assim, antes que aquilo que é enunciado aconteça, ninguém pode saber com certeza a verdade ou a falsidade de proposições sobre o futuro contingente. Os teólogos, entretanto, não podem admitir essa conclusão: a revelação nos diz que Deus sabe, com toda certeza e desde a eternidade, que parte da contradição será determinadamente verdadeira ou falsa. Para Ockham, a solução desse problema parece conter desde uma abordagem especial da formulação lógica desta questão até o reconhecimento de uma certa limitação do conhecimento humano. É a análise dessa solução o que pretendemos mostrar no trabalho que se segue. / The \"William of Ockham\'s Exposition on the \'Perihermenias\' of Aristotle (i.e., the Aristotelian De Interpretatione)\" brings a problem \"to the truth and to the theologians\": according to Aristotle, the hypothetical proposition which contains a pair of contradictories related to the same future contingent thing is neither determinately true nor determinately false - once none of their contradictories are neither determinately true nor determinately false. Therefore, before that thing happens, nobody can know with certainty the truth or the falsity of any proposition about future contingent things. Theologians, however, cannot accept this conclusion: the faith teaches that God knows, with certainty and from eternity, which part of that pair of contradictories is determinately true or determinately false. In Ockham\'s view, the solution of this argument seems to pass by a special approach of the logical view of this question and by the assumption of limits for the human knowledge. It\'s on the analysis of this solution that the present work is related.
159

Bayesian analysis of a 2 x 2 contingency table with prior beliefs of association.

January 1995 (has links)
by Wai-chuen Tso. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 90-94). / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Prior Information --- p.5 / Chapter 2.1 --- Prior Distribution --- p.6 / Chapter 2.2 --- Quantification of Prior Belief --- p.10 / Chapter 2.2.1 --- Prior Belief --- p.10 / Chapter 2.2.2 --- Some Basic Concepts of Fuzzy Set Theory --- p.12 / Chapter 2.2.3 --- Quantification --- p.16 / Chapter 2.3 --- Specification and Determination of Model Parameters --- p.20 / Chapter 2.3.1 --- A Questionnaire --- p.21 / Chapter 2.3.2 --- Parameter Value --- p.22 / Chapter 2.3.3 --- Determination of Degree of Fuzziness --- p.23 / Chapter 2.4 --- Comments --- p.26 / Chapter 2.4.1 --- Interpretation of Time Length of Poisson Process --- p.26 / Chapter 2.4.2 --- Likelihood Interpretation of Membership Value --- p.28 / Chapter 2.4.3 --- Comparison with Existing Modeling --- p.30 / Chapter 2.4.4 --- Conclusion of Prior Information --- p.31 / Chapter 3 --- Posterior Analysis --- p.33 / Chapter 3.1 --- Posterior Analysis by Monte Carlo Method --- p.34 / Chapter 3.1.1 --- Monte Carlo Method --- p.34 / Chapter 3.1.2 --- Estimation of Posterior Mean and Posterior Variance of Log-odds Ratio --- p.35 / Chapter 3.1.3 --- Construction of Credible Region of Log-odds Ratio --- p.38 / Chapter 3.1.4 --- Estimation of Posterior Mean of Cell Probability --- p.41 / Chapter 3.2 --- Sampling of Prior Cell Frequency Vector by Gibbs Sampler --- p.42 / Chapter 3.2.1 --- Gibbs Sampler --- p.42 / Chapter 3.2.2 --- Two Sampling Algorithms --- p.45 / Chapter 3.2.3 --- Acceptance-Rejection Algorithm --- p.50 / Chapter 3.3 --- Some Practical Problems --- p.51 / Chapter 3.3.1 --- Number of Iterations in Gibbs Sampler --- p.51 / Chapter 3.3.2 --- Sample Size of Gibbs Sample --- p.53 / Chapter 4 --- Simulation Study --- p.58 / Chapter 4.1 --- Multinomial Model --- p.59 / Chapter 4.1.1 --- Determination of Number of Iterations --- p.61 / Chapter 4.1.2 --- Determination of Sample Size --- p.62 / Chapter 4.1.3 --- Posterior Estimation --- p.63 / Chapter 4.1.4 --- Sensitivity Analysis --- p.64 / Chapter 4.2 --- Poisson Model --- p.71 / Chapter 4.2.1 --- Determination of Number of Iterations --- p.72 / Chapter 4.2.2 --- Determination of Sample Size --- p.73 / Chapter 4.2.3 --- Posterior Estimation --- p.74 / Chapter 4.2.4 --- Sensitivity Analysis --- p.75 / Chapter 4.3 --- Conclusion --- p.82 / Chapter 5 --- Conclusions and Discussions --- p.85 / References --- p.90
160

Power System State Estimation and Contingency Constrained Optimal Power Flow - A Numerically Robust Implementation

Pajic, Slobodan 01 May 2007 (has links)
The research conducted in this dissertation is divided into two main parts. The first part provides further improvements in power system state estimation and the second part implements Contingency Constrained Optimal Power Flow (CCOPF) in a stochastic multiple contingency framework. As a real-time application in modern power systems, the existing Newton-QR state estimation algorithms are too slow and too fragile numerically. This dissertation presents a new and more robust method that is based on trust region techniques. A faster method was found among the class of Krylov subspace iterative methods, a robust implementation of the conjugate gradient method, called the LSQR method. Both algorithms have been tested against the widely used Newton-QR state estimator on the standard IEEE test networks. The trust region method-based state estimator was found to be very reliable under severe conditions (bad data, topological and parameter errors). This enhanced reliability justifies the additional time and computational effort required for its execution. The numerical simulations indicate that the iterative Newton-LSQR method is competitive in robustness with classical direct Newton-QR. The gain in computational efficiency has not come at the cost of solution reliability. The second part of the dissertation combines Sequential Quadratic Programming (SQP)-based CCOPF with Monte Carlo importance sampling to estimate the operating cost of multiple contingencies. We also developed an LP-based formulation for the CCOPF that can efficiently calculate Locational Marginal Prices (LMPs) under multiple contingencies. Based on Monte Carlo importance sampling idea, the proposed algorithm can stochastically assess the impact of multiple contingencies on LMP-congestion prices.

Page generated in 0.1065 seconds