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Evaluating the Benefits of Optimal Allocation of Wind Turbines for Distribution Network OperatorsSiano, P., Mokryani, Geev January 2015 (has links)
No / This paper proposes a hybrid optimization method for optimal allocation of wind turbines (WTs) that combines a fast and elitist multiobjective genetic algorithm (MO-GA) and the market-based optimal power flow (OPF) to jointly minimize the total energy losses and maximize the net present value associated with the WT investment over a planning horizon. The method is conceived for distributed-generator-owning distribution network operators to find the optimal numbers and sizes of WTs among different potential combinations. MO-GA is used to select, among all the candidate buses, the optimal sites and sizes of WTs. A nondominated sorting GA II procedure is used for finding multiple Pareto-optimal solutions in a multiobjective optimization problem, while market-based OPF is used to simulate an electricity market session. The effectiveness of the method is demonstrated with an 84-bus 11.4-kV radial distribution system.
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Regularization of inverse problems in image processingJalalzai, Khalid 09 March 2012 (has links) (PDF)
Les problèmes inverses consistent à retrouver une donnée qui a été transformée ou perturbée. Ils nécessitent une régularisation puisque mal posés. En traitement d'images, la variation totale en tant qu'outil de régularisation a l'avantage de préserver les discontinuités tout en créant des zones lisses, résultats établis dans cette thèse dans un cadre continu et pour des énergies générales. En outre, nous proposons et étudions une variante de la variation totale. Nous établissons une formulation duale qui nous permet de démontrer que cette variante coïncide avec la variation totale sur des ensembles de périmètre fini. Ces dernières années les méthodes non-locales exploitant les auto-similarités dans les images ont connu un succès particulier. Nous adaptons cette approche au problème de complétion de spectre pour des problèmes inverses généraux. La dernière partie est consacrée aux aspects algorithmiques inhérents à l'optimisation des énergies convexes considérées. Nous étudions la convergence et la complexité d'une famille récente d'algorithmes dits Primal-Dual.
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Discrete Scale-Space Theory and the Scale-Space Primal SketchLindeberg, Tony January 1991 (has links)
This thesis, within the subfield of computer science known as computer vision, deals with the use of scale-space analysis in early low-level processing of visual information. The main contributions comprise the following five subjects: The formulation of a scale-space theory for discrete signals. Previously, the scale-space concept has been expressed for continuous signals only. We propose that the canonical way to construct a scale-space for discrete signals is by convolution with a kernel called the discrete analogue of the Gaussian kernel, or equivalently by solving a semi-discretized version of the diffusion equation. Both the one-dimensional and two-dimensional cases are covered. An extensive analysis of discrete smoothing kernels is carried out for one-dimensional signals and the discrete scale-space properties of the most common discretizations to the continuous theory are analysed. A representation, called the scale-space primal sketch, which gives a formal description of the hierarchical relations between structures at different levels of scale. It is aimed at making information in the scale-space representation explicit. We give a theory for its construction and an algorithm for computing it. A theory for extracting significant image structures and determining the scales of these structures from this representation in a solely bottom-up data-driven way. Examples demonstrating how such qualitative information extracted from the scale-space primal sketch can be used for guiding and simplifying other early visual processes. Applications are given to edge detection, histogram analysis and classification based on local features. Among other possible applications one can mention perceptual grouping, texture analysis, stereo matching, model matching and motion. A detailed theoretical analysis of the evolution properties of critical points and blobs in scale-space, comprising drift velocity estimates under scale-space smoothing, a classification of the possible types of generic events at bifurcation situations and estimates of how the number of local extrema in a signal can be expected to decrease as function of the scale parameter. For two-dimensional signals the generic bifurcation events are annihilations and creations of extremum-saddle point pairs. Interpreted in terms of blobs, these transitions correspond to annihilations, merges, splits and creations. Experiments on different types of real imagery demonstrate that the proposed theory gives perceptually intuitive results. / <p>QC 20120119</p>
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Formational leadership : Wesleyan spirituality and psychological growth as means of facilitating spiritual and emotional maturity and counteracting toxic leadershipKilian, Marcus Klaus 06 1900 (has links)
Includes bibliographical references (leaves 191-202) / This dissertation addresses the problem of toxic leadership, especially in Christian contexts. Toxic leadership behaviors of narcissistic and obsessive-compulsive leaders will be emphasized. To counteract toxic Christian leadership, this dissertation proposes a leadership development model, called formational leadership, which is based on Wesleyan spirituality. Formational leadership emphasizes the spiritual, emotional, and ethical development processes in the leader and includes an analysis of orthokardia, orthodynamis, and orthopraxis. These components have a circular relationship with one another. Orthokardia includes the concepts of spiritual and emotional maturity that a Christian leader needs to develop in order to become an ethical and effective leader. Orthodynamis includes right power and influence motives based on Christian affections that should inform formational leadership. Orthopraxis refers to right and just leadership behaviors informed by Wesley’s social holiness and justice values that need to be adopted as organizational core values. The implications of these components for leadership development are outlined in chapters 4-6 that include practical steps for helping toxic leaders change their dysfunctional and sinful intentions and behaviors. / Christian Spirituality, Church History and Missiology / M. Th. (Theological ethics with specialisation in Christian Leadership in context)
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Infeasibility detection and regularization strategies in nonlinear optimization / Détection de la non-réalisabilité et stratégies de régularisation en optimisation non linéaireTran, Ngoc Nguyen 26 October 2018 (has links)
Dans cette thèse, nous nous étudions des algorithmes d’optimisation non linéaire. D’une part nous proposons des techniques de détection rapide de la non-réalisabilité d’un problème à résoudre. D’autre part, nous analysons le comportement local des algorithmes pour la résolution de problèmes singuliers. Dans la première partie, nous présentons une modification d’un algorithme de lagrangien augmenté pour l’optimisation avec contraintes d’égalité. La convergence quadratique du nouvel algorithme dans le cas non-réalisable est démontrée théoriquement et numériquement. La seconde partie est dédiée à l’extension du résultat précédent aux problèmes d’optimisation non linéaire généraux avec contraintes d’égalité et d’inégalité. Nous proposons une modification d’un algorithme de pénalisation mixte basé sur un lagrangien augmenté et une barrière logarithmique. Les résultats théoriques de l’analyse de convergence et quelques tests numériques montrent l’avantage du nouvel algorithme dans la détection de la non-réalisabilité. La troisième partie est consacrée à étudier le comportement local d’un algorithme primal-dual de points intérieurs pour l’optimisation sous contraintes de borne. L’analyse locale est effectuée sans l’hypothèse classique des conditions suffisantes d’optimalité de second ordre. Celle-ci est remplacée par une hypothèse plus faible basée sur la notion de borne d’erreur locale. Nous proposons une technique de régularisation de la jacobienne du système d’optimalité à résoudre. Nous démontrons ensuite des propriétés de bornitude de l’inverse de ces matrices régularisées, ce qui nous permet de montrer la convergence superlinéaire de l’algorithme. La dernière partie est consacrée à l’analyse de convergence locale de l’algorithme primal-dual qui est utilisé dans les deux premières parties de la thèse. En pratique, il a été observé que cet algorithme converge rapidement même dans le cas où les contraintes ne vérifient l’hypothèse de qualification de Mangasarian-Fromovitz. Nous démontrons la convergence superlinéaire et quadratique de cet algorithme, sans hypothèse de qualification des contraintes. / This thesis is devoted to the study of numerical algorithms for nonlinear optimization. On the one hand, we propose new strategies for the rapid infeasibility detection. On the other hand, we analyze the local behavior of primal-dual algorithms for the solution of singular problems. In the first part, we present a modification of an augmented Lagrangian algorithm for equality constrained optimization. The quadratic convergence of the new algorithm in the infeasible case is theoretically and numerically demonstrated. The second part is dedicated to extending the previous result to the solution of general nonlinear optimization problems with equality and inequality constraints. We propose a modification of a mixed logarithmic barrier-augmented Lagrangian algorithm. The theoretical convergence results and the numerical experiments show the advantage of the new algorithm for the infeasibility detection. In the third part, we study the local behavior of a primal-dual interior point algorithm for bound constrained optimization. The local analysis is done without the standard assumption of the second-order sufficient optimality conditions. These conditions are replaced by a weaker assumption based on a local error bound condition. We propose a regularization technique of the Jacobian matrix of the optimality system. We then demonstrate some boundedness properties of the inverse of these regularized matrices, which allow us to prove the superlinear convergence of our algorithm. The last part is devoted to the local convergence analysis of the primal-dual algorithm used in the first two parts of this thesis. In practice, it has been observed that this algorithm converges rapidly even in the case where the constraints do not satisfy the Mangasarian-Fromovitz constraint qualification. We demonstrate the superlinear and quadratic convergence of this algorithm without any assumption of constraint qualification.
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Content Algebras and Zero-Divisors / Inhaltsalgebren und NullteilerNasehpour, Peyman 10 February 2011 (has links)
This thesis concerns two topics. The first topic, that is related to the Dedekind-Mertens Lemma, the notion of the so-called content algebra, is discussed in chapter 2. Let $R$ be a commutative ring with identity and $M$ be a unitary $R$-module and $c$ the function from $M$ to the ideals of $R$ defined by $c(x) = \cap \lbrace I \colon I \text{~is an ideal of~} R \text{~and~} x \in IM \rbrace $. $M$ is said to be a \textit{content} $R$-module if $x \in c(x)M $, for all $x \in M$. The $R$-algebra $B$ is called a \textit{content} $R$-algebra, if it is a faithfully flat and content $R$-module and it satisfies the Dedekind-Mertens content formula. In chapter 2, it is proved that in content extensions, minimal primes extend to minimal primes, and zero-divisors of a content algebra over a ring which has Property (A) or whose set of zero-divisors is a finite union of prime ideals are discussed. The preservation of diameter of zero-divisor graph under content extensions is also examined. Gaussian and Armendariz algebras and localization of content algebras at the multiplicatively closed set $S^ \prime = \lbrace f \in B \colon c(f) = R \rbrace$ are considered as well.
In chapter 3, the second topic of the thesis, that is about the grade of the zero-divisor modules, is discussed. Let $R$ be a commutative ring, $I$ a finitely generated ideal of $R$, and $M$ a zero-divisor $R$-module. It is shown that the $M$-grade of $I$ defined by the Koszul complex is consistent with the definition of $M$-grade of $I$ defined by the length of maximal $M$-sequences in I$.
Chapter 1 is a preliminarily chapter and dedicated to the introduction of content modules and also locally Nakayama modules.
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'True receivers': Rilke and the contemporary poetics of listening (Part 1) ; Poems: Small weather (Part 2)Lawrence, Faith January 2015 (has links)
Part 1: ‘True Receivers': Rilke and the Contemporary Poetics of Listening In this part of this thesis I argue that a contemporary ‘poetics of listening' has emerged in the UK, and explore the writing of three of our most significant poets - John Burnside, Kathleen Jamie and Don Paterson - to find out why they have become interested in the idea of the poet as a ‘listener'. I suggest that the appeal of this listening stance accounts for their engagement with the poetry of Rainer Maria Rilke, who thought of himself as a listening ‘receiver'; it is proposed that Rilke's notion of ‘receivership' and the way his poems relate to the earthly (or the ‘non-human') also account for the general ‘intensification' of interest in his work. An exploration of the shifting status of listening provides context for this study, and I pay particular attention to the way innovations in audio and communications technology influenced Rilke's late sequences the Duino Elegies and The Sonnets to Orpheus. A connection is made between Rilke's ‘listening poetics' and the ‘listening' stance of Ted Hughes and Edward Thomas; this establishes a ‘listening lineage' for the contemporary poets considered in the thesis. I also suggest that there are intriguing similarities between the ideas of listening that are emerging in contemporary poetics and Hélène Cixous' concept of ‘écriture féminine'. Exploring these similarities helps us to understand the implications of the stance of the poet-listener, which is a counter to the idea that as a writer you must ‘find your voice'. Finally, it is proposed that ‘a poetics of listening' would benefit from an enriched taxonomy. Part 2 of the thesis is a collection of my poems entitled ‘Small Weather'.
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A Multi-Factor Stock Market Model with Regime-Switches, Student's T Margins, and Copula DependenciesBerberovic, Adnan, Eriksson, Alexander January 2017 (has links)
Investors constantly seek information that provides an edge over the market. One of the conventional methods is to find factors which can predict asset returns. In this study we improve the Fama and French Five-Factor model with Regime-Switches, student's t distributions and copula dependencies. We also add price momentum as a sixth factor and add a one-day lag to the factors. The Regime-Switches are obtained from a Hidden Markov Model with conditional Student's t distributions. For the return process we use factor data as input, Student's t distributed residuals, and Student's t copula dependencies. To fit the copulas, we develop a novel approach based on the Expectation-Maximisation algorithm. The results are promising as the quantiles for most of the portfolios show a good fit to the theoretical quantiles. Using a sophisticated Stochastic Programming model, we back-test the predictive power over a 26 year period out-of-sample. Furthermore we analyse the performance of different factors during different market regimes.
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Řízení rizik ve stavebním podniku / Risk Management inside Construction CompanyResl, Jan January 2014 (has links)
The aim of the thesis is to analyse issues of risk management in a construction company, especially in the context of construction contracts implementation. The first part is devoted to applied terminology and interpretation of relevant terms, followed by a classification of risks from different perspectives, including the risks’ possible further sub classification. Furthermore, significant risk resources and construction participants who might be affected by the risks are presented. The third chapter deals with risk management; individual phases of this complex process are described herein, including their correct sequences, as well as a selection of methods and techniques that are standardly used in risk management. The last, fourth chapter summarises the problems of risk management on a practical example, where a construction company implements a construction contract by applying selected risk management methodologies.
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