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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.
111

Análise e desenvolvimento de algoritmos eficientes de programação linear para o problema de planejamento de sistemas de transmissão a longo prazo /

Hashimoto, Selma Helena Marchiori. January 2005 (has links)
Orientador: Rubén Augusto Romero Lázaro / Banca: Jose Roberto Sanches Mantovani / Banca: Sergio Azevedo de Oliveira / Banca: Antônio César Baleeiro Alves / Banca: Eduardo Nobuhiro Asada / Resumo: O problema de planejamento de sistemas de transmissão é um problema de programação não-linear inteira mista (PNLIM) quando é usado o modelo DC. Praticamente todos os algoritmos usados para resolver este problema utilizam uma subrotina de programação linear (PL) para resolver problemas de PL resultantes do algoritmo de solução do problema de planejamento. Às vezes a resolução desses problemas de PL representa o maior esforço computacional dos algoritmos de planejamento. A particularidade desses problemas de PL é que, na solução ótima, apenas algumas restrições de desigualdade estão ativas. Este trabalho considera a formulação e a implementação computacional de vários algoritmos de PL resultantes, ou seja, os algoritmos propostos fazem modificações nos problemas de PL resultantes dos modelos de transportes e DC de maneira que apresentam uma única restrição de igualdade, a equação de balanço de potência ativa, e muitas restrições de desigualdade. É usado um algoritmo dual simplex canalizado e uma estratégia de relaxação para resolver esses problemas de PL que inicia o processo de otimização com uma única restrição de igualdade e, em cada passo, é adicionada a restrição mais violada. Portanto, a lógica de trabalho é parecida com a proposta apresentada por Brian Stott para o planejamento da operação de sistemas elétricos. Os resultados encontrados mostram um desempenho superior do algoritmo quando comparados com métodos do tipo primal simplex. / Abstract: The transmission network planning problem is a non linear integer mixed programming problem (NLIMP) which used the DC model. Most of the algorithms used to solve this problem use a linear programming subroutine (LP) to solve LP problems resulting from planning algorithms. Sometimes the resolution of these LP problems represents a major computational effort of planning algorithms. The particularity of these LP problems in optimal solution is that only some inequality constraints are binding. This work considers the formulation and the computational implementation of algorithms several of the LP problems resulting, i.e., the proposed algorithms make modifications in the LP problems resulting of the transports and DC models so that present an only equality constraint, only one equality constraint, the power flow equation, and many inequality constraints. It is used a dual simplex algorithm and a relaxation strategy to solve these LP problems_ which start the optimization process with only one equality constraint and, in each step, the most unfeasible constraint is added. Then, the logic used is similar to the proposal presented in Brian Stott for electric systems operation planning. The results show a higher performance of the algorithm when compared to primal simplex methods. / Doutor
112

A Bounded Affinity Theory of Religion and the Paranormal

Baker, Joseph O., Bader, Christopher D., Mencken, F. Carson 01 December 2016 (has links)
We outline a theory of bounded affinity between religious experiences and beliefs and paranormalism, which emphasizes that religious and paranormal experiences and beliefs share inherent physiological, psychological, and ontological similarities. Despite these parallels, organized religious groups typically delineate a narrow subset of experiences and explanatory frames as acceptable and True, banishing others as either false or demonic. Accordingly, the theory provides a revised definition of the “paranormal” as beliefs and experiences explicitly rejected by science and organized religions. To demonstrate the utility of the theory, we show that, after controlling for levels of conventional religious practice, there is a strong, positive relationship between claiming Christian-based religious experiences and believing in, pursuing, and experiencing the paranormal, particularly among individuals not strongly tethered to organized religion. Bounded affinity theory makes sense of recent non-linear and complex moderation findings in the empirical literature and reiterates the importance of the paranormal for studies of religion.
113

Financial advice and consumer protection / Conseil financier et protection des consommateurs

Kim, Areum 02 October 2014 (has links)
Cette thèse porte sur le régime de protection des consommateurs qui vise à prévenir les ventes abusives dans les services de conseil en investissement. Elle examine les conflits d'intérêts dus au comportement des conseillers financiers qui peuvent entraîner des ventes abusives. Le fait que la rationalité du consommateur puisse être limitée signifie que les consommateurs financiers traditionnellement considérés comme des clients de détail ou des investisseurs de détail sont en effet exposés au risque de conflits d'intérêts dans le processus de conseil en investissement et nécessitent donc une protection accrue. La directive MIF a récemment renforcé son dispositif afin de protéger plus efficacement les consommateurs contre le problème persistant des ventes abusives. La modification de la réglementation de la protection des consommateurs est significative en ce qu'elle renforce le régime général de protection des consommateurs de la directive MIF en mettant l'accent sur la vulnérabilité réelle des consommateurs. Elle contribue en outre à la promotion du système de protection du consommateur en imposant des devoirs de comportement aux sociétés financières qui doivent gérer des conflits d'intérêts spécifiques dans le cadre du grand principe de la protection des consommateurs. Cependant, même si l’intention à l’origine de son introduction est largement reconnue, la mise en place et la mise en œuvre pratiques de certains règlements devraient rencontrer des difficultés et donc nécessiter que des mesures supplémentaires soient prises. / The thesis deals with the consumer protection scheme which aims to prevent mis-selling in investment advice services. It examines the conflicts of interest which appear in the behavior of investment advisors which may ultimately cause mis-selling scandals. The research findings of behavioral economics that the consumer’s rationality can be bounded indicate that financial consumers who are traditionally considered as retail clients or retail investors are indeed vulnerable to the risk of conflicts of interest in investment advisory processes and thus need enhanced consumer protection. MiFID I has recently strengthened its scheme with a view to protecting consumers more effectively from persistent problems of mis-selling. The amendment of the consumer protection regulation is meaningful in that it strengthens the overall consumer protection scheme within the MiFID with a focus on the actual vulnerability of consumers. Furthermore, it contributes to the fostering of the consumer protection system by imposing behavioral duties on financial firms which manage specific conflicts of interest under the important principle of consumer protection. However, even though the intention at the origin of its introduction is widely recognized, it is expected that some difficulties will arise when some of the regulations are virtually introduced and implemented, and thus supplementary measures will have to be established.
114

Bounded Point Derivations on Certain Function Spaces

Deterding, Stephen 01 January 2018 (has links)
Let 𝑋 be a compact subset of the complex plane and denote by 𝑅𝑝(𝑋) the closure of rational functions with poles off 𝑋 in the 𝐿𝑝(𝑋) norm. We show that if a point 𝑥0 admits a bounded point derivation on 𝑅𝑝(𝑋) for 𝑝 > 2, then there is an approximate derivative at 𝑥0. We also prove a similar result for higher order bounded point derivations. This extends a result of Wang, which was proven for 𝑅(𝑋), the uniform closure of rational functions with poles off 𝑋. In addition, we show that if a point 𝑥0 admits a bounded point derivation on 𝑅(𝑋) and if 𝑋 contains an interior cone, then the bounded point derivation can be represented by the difference quotient if the limit is taken over a non-tangential ray to 𝑥0. We also extend this result to the case of higher order bounded point derivations. These results were first shown by O'Farrell; however, we prove them constructively by explicitly using the Cauchy integral formula.
115

Demand for genetically modified food : theory and empirical findings

Kaye-Blake, William Henry January 2006 (has links)
As economies develop, novel products are created and markets for these products arise. Genetically modified food (GMF) is an example of such a novel product and provides economists with the opportunity to investigate an infant market. Of particular interest with GMF is the impact of consumer reactions on the market. The response of consumers to GMF and their willingness to pay for it has emerged as an important factor in the development of this technology. This research investigates these consumer responses. Prior research suggests that two aspects of consumer behaviour may be relevant for the GMF market. First, consumers may react differently to different types of GMF, so that some products are potentially more economically viable. Secondly, some consumers appear to prefer not having GMF at all. Consumer behaviour is often framed according to neoclassical economic theory. Consumer preferences over goods and the attributes of those goods are generally held to have certain properties. The aspects of consumers’ reactions to GMF noted above, however, may be in conflict with two properties of preferences in neoclassical theory. First, preferences over food attributes are not separable, but may interact with each other. Secondly, some consumers may have preferences regarding GMF that are not continuous. As a result, aggregate impacts of introducing GMF may be difficult to measure, which raises a third issue for investigation, aggregation. Finally, an alternative model of consumer behaviour is bounded rationality, which theorises that choices may be discontinuous as a result of specific protocols. It also suggests that consumers seek to make good-enough choices, rather than attempting to maximise their satisfaction. Thus, optimisation or maximisation is the fourth issue considered in this thesis. In order to investigate these properties of consumers’ preferences, a choice experiment survey was developed. The strength of a choice experiment for examining these issues is its focus on the impact of each product attribute on a respondent’s choices. Thus, it may be possible to identify potentially discontinuous choice patterns and to identify choices affected by interactions between GM technology and other food attributes. Results from a neoclassical analysis of the survey data suggest that some consumers consider the type of benefit created with GM technology in making their choices. In addition, one-quarter to one-half of respondents may have had discontinuous preferences with respect to GMF. Reactions to GMF appear related to respondents’ attitudes, but not to socio-economic or demographic descriptors. As a result, aggregate measures of the impact of GMF may not fully account for consumers’ responses. A boundedly rational model also has reasonable goodness of fit, and may provide a different perspective on consumer behaviour. It is hoped that the results of this research provide a better understanding of consumer behaviour regarding GMF and, by extension, of the process of consumer adoption of novel products. It is further hoped that this attempt to incorporate choice protocols into discrete choice analysis will provide a useful example for further research.
116

Online regulations of low order systems under bounded control

Arora, Sumit 30 September 2004 (has links)
Time-optimal solutions provide us with the fastest means to regulate a system in presence of input constraints. This advantage of time-optimal control solutions is offset by the fact that their real-time implementation involves computationally intensive iterative techniques. Moreover, time-optimal controls depend on the initial state and have to be recalculated for even the slightest perturbation. Clearly time-optimal controls are not good candidates for online regulation. Consequently, the search for alternatives to time-optimal solutions is a very active area of research. The work described here is inspired by the simplicity of optimal-aim concept. The "optimal-aim strategies" provide online regulation in presence of bounded inputs with minimal computational effort. These are based purely on state-space geometry of the plant and are inherently adaptive in nature. Optimal-aim techniques involve aiming of trajectory derivative (or the state velocity vector) so as to approach the equilibrium state in the best possible manner. This thesis documents the efforts to develop an online regulation algorithm for systems with input constraints. Through a number of hypotheses focussed on trying to reproduce the exact time-optimal solution, the diffculty associated with this task is demonstrated. A modification of optimal-aim concept is employed to develop a novel regulation algorithm. In this algorithm, aim directions are chosen in a special manner to generate the time-optimal control approximately. The control scheme thus developed is shown to be globally stabilizing for systems having eigenvalues in the CLHP (closed left half-plane). It is expected that this method or its modifications can be extended to higher dimensional systems as a part of future research. An alternative control algorithm involving a simple state-space aiming concept is also developed and discussed.
117

On infinite matrices whose entries satisfying certain dyadic recurrent formula

Hsu, Chia-ming 25 July 2007 (has links)
Let (b$_{i,j}$) be a bounded matrix on extit{ l}$^{2}$, $Bbb T={zinBbb C:|z|=1}$, and A be a bounded matrix on L$^{ 2}(mathbb{T)}$ satisfying the conditions 1.$langle Az^{2j},z^{2i} angle =sigma ^{-1}b_{ij}+|alpha |^{2}sigma ^{-1}langle Az^{j},z^{i} angle $; 2.$langle Az^{2j},z^{2i-1} angle =-alpha sigma ^{-1}b_{ij}+alpha sigma ^{-1}langle Az^{j},z^{i} angle $; 3.$langle Az^{2j-1},z^{2i} angle =-overline{alpha }sigma ^{-1}b_{ij}+overline{alpha }sigma ^{-1}langle Az^{j},z^{i} angle$; 4.$langle Az^{2j-1},z^{2i-1} angle =|alpha |^{2}sigma ^{-1}b_{ij}+sigma ^{-1}langle Az^{j},z^{i} angle $ hspace{-0.76cm} for all $i,jin mathbb{Z}$, where $sigma =1+|alpha |^{2},,alpha in mathbb{C},alpha eq0$. The above conditions evidently suggests that there is a "dyadic" relation in the entries of $A$. Here in the following picture illustrates how each $ij-$th entry of $A$ generates the 2 by 2 block in $A$ with entries ${a_{2i 2j}, a_{2i-1 2j}, a_{2i 2j-1}, a_{2i-1 2j-1}}.$ vspace{-0.3cm} egin{figure}[hp] egin{center} includegraphics[scale=0.42]{cubic.pdf} end{center} vspace{-0.8cm}caption{The dyadic recurrent form} end{figure} It has been shown [2] that $displaystyle A=sum_{n=0}^{infty }S^{n}BS^{ast n}$, where $Sz^i=sigma ^{-1/2}(overline{alpha }z^{2i}+z^{2i-1})$ and $$B=sumlimits_{i=-infty}^infty sumlimits_{j=-infty}^infty b_{ij}(u_{i}otimes u_{j}), u_{i}(z)=sigma ^{-1/2}z^{2i-1}(alpha -z).$$ In this paper, we shall use the above relations to compute $langle a_{i,j} angle $ explicitly. ewline Key words: shift operator, bounded matrix, dyadic recurrent formula, slant Toeplitz operator, separable Hilbert space 2.$langle Az^{2j},z^{2i-1} angle =-alpha sigma ^{-1}b_{ij}+alpha sigma ^{-1}langle Az^{j},z^{i} angle $ 3.$langle Az^{2j-1},z^{2i} angle =-overline{alpha }sigma ^{-1}b_{ij}+overline{alpha }sigma ^{-1}langle Az^{j},z^{i} angle $ 4.$langle Az^{2j-1},z^{2i-1} angle =|alpha |^{2}sigma ^{-1}b_{ij}+sigma ^{-1}langle Az^{j},z^{i} angle $ for all $i,jin mathbb{Z}$, where $sigma =1+|alpha |^{2},,alpha in mathbb{C},alpha eq0$ egin{figure}[hp] egin{center} includegraphics[scale=0.42]{cubic.pdf} end{center} caption{The dyadic recurrent form} end{figure} Since it has been shown [2] that $displaystyle A=sum_{n=0}^{infty }S^{n}BS^{ast n}$, where $ Sz^i=sigma ^{-1/2}(overline{alpha }z^{2i}+z^{2i-1})$ $ B=sum sum b_{ij}(u_{i}otimes u_{j})$ ;;; which $u_{i}(z)=sigma ^{-1/2}z^{2i-1}(alpha -z)$ Then we can use it to compute $langle Az^{j},z^{i} angle $ explicity if A satisfies the previous condition. ewline Key words: shift operator, bounded matrix, dyadic recurrent formula, slant Toeplitz operator, separable Hilbert space
118

Organizational choice and behaviour : a framework for analyzing decision-making in co-operative organizations

Heit, Jason D 19 September 2007
This thesis proposes a conceptual framework to analyze the choice of organizational form and assess the shifts in organizational behaviour and form. This thesis argues that the choice of organizational form is an outcome of an individuals or groups mode of identification within the dominant organizational form and property rights structure of society. The framework places/situates the investor-owned firm (IOF) in a position of identification with the dominant ideology and property rights structure of society. The state-owned enterprise (SOE) occupies a position of counter-identification with the dominant ideology and property rights structure of society. The co-operative, on the other hand, represents a dis-identification with both the IOF and the SOE as this form works on and against the ideologies and property rights structures associated with the two former organizational forms.<p>Further, the thesis argues that endogenous and exogenous pressures may cause some organizations to shift their organizational behaviour and form. The researcher examines how internal problems in co-operative organizations (i.e., horizon and principal-agent problems) can exacerbate exogenous pressures (i.e., increasing competition and/or government deregulation) from the market and/or state causing the co-op to imitate the strategies or property rights structure of the IOF in order to cope with these issues. <p>Profiles of the formation of the Saskatchewan Co-operative Wholesale Society and the Consumers Co-operative Refineries Limited and the conversion of the Saskatchewan Wheat Pool are used to illustrate the conceptual framework and support the arguments made in this thesis.
119

Improved approximation guarantees for lower-bounded facility location problem

Ahmadian, Sara January 2010 (has links)
We consider the lower-bounded facility location (LBFL) problem (, also known as load-balanced facility location), which is a generalization of uncapacitated facility location (UFL) problem where each open facility is required to serve a minimum number of clients. More formally, in the LBFL problem, we are given a set of clients Ɗ , a set of facilities Ƒ, a non-negative facility-opening cost f_i for each i ∈ Ƒ, a lower bound M, and a distance metric c(i,j) on the set Ɗ ∪ Ƒ, where c(i,j) denotes the cost of assigning client j to facility i. A feasible solution S specifies the set of open facilities F_S ⊆ Ƒ and the assignment of each client j to an open facility i(j) such that each open facility serves at least M clients. Our goal is to find feasible solution S that minimizes ∑_{i ∈ F_S} f_i + ∑_j c(i,j). The current best approximation ratio for LBFL is 550. We substantially advance the state-of-the-art for LBFL by devising an approximation algorithm for LBFL that achieves a significantly-improved approximation guarantee of 83.
120

GBNM : un algorithme d'optimisation par recherche directe. Application à la conception de monopalmes de nage

Luersen, Marco Antonio 14 May 1993 (has links) (PDF)
Dans ce travail, une méthode d'optimisation à coût fini, essentiellement locale,mais qui devient globale lorsque le nombre d'analyses croît est développée. La ± globalisation α vient de ré-initialisations probabilisées de recherches locales prenant en compte les points de départ et de convergence passés. L'optimiseur local est une version améliorée de la méthode de Nelder-Mead, où les variables sont bornées, où les contraintes d'inégalité sont prises en compte par pénalisation adaptative, et où les dégénérescences du simplexe sont traitées par ré-initialisation. Cette méthode, appelée ± Globalized and Bounded Nelder-Mead α (GBNM), est testée sur des fonctions multimodales et des problèmes de conception de stratifiés composites. Puis, des applications plus complexes sont traitées avec GBNM : l'optimisation de la raideur de flexion et l'identification des positions des sauts de plis de monopalmes de nage.

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