The proposition of this dissertation is that superior capital budgeting solutions can be attained by not only analyzing projects individually but rather as part of a portfolio of projects that has the objective of maximizing the company’s range of multiple objectives, not only the economic benefit. The dissertation starts with a detailed study of current techniques and an assessment of flaws and shortcomings. This study concludes with the requirements that any new approach or model must address in order to improve on the current practices. Based on these requirements, a new model is developed based on the portfolio approach that integrates all the assumptions, constraints, project and variable interrelationships. An important feature of the model is that it selects its portfolio of capital projects in such a way that it optimizes support for the company’s multiple objectives, not only the economic objective. The dissertation concludes with the application of this model to a hypothetical case. It is concluded that, by developing and using this model, a company can improve the analysis required before capital budgets are finalized. / Dissertation (MEng (Industrial Engineering))--University of Pretoria, 2006. / Industrial and Systems Engineering / unrestricted

Esta tese de doutorado aborda os tópicos de modelagem e de reconhecimento de objetos estruturados, ou sistemas estruturados de objetos, em imagens. Um objeto ou sistema estruturado é aquele que pode ser descrito através de elementos primitivos que o compõem e pelas relações existentes entre esses elementos. Por exemplo, uma aeronave pode ser descrita pelos seguintes elementos primitivos: asas direita e esquerda, fuselagem e cockpit. O aspecto relacional de um objeto estruturado direciona sua representação computacional e seu reconhecimento em imagens ao paradigma estrutural de reconhecimento de padrões. Contudo, a variabilidade das características dos seus elementos primitivos é melhor representada através do paradigma estatístico de reconhecimento de padrões. Devido à complementaridade dos paradigmas, a conjunção dessas abordagens é um tema de pesquisa de interesse atual. Para conjugar esses dois aspectos, esta tese propôs uma metodologia que combina o conhecimento a priori das relações que caracterizam um objeto estruturado com dados estatísticos coletados de amostras desse objeto, num modelo híbrido denominado grafo estatístico-relacional (GER). Segundo essa representação, foi estudada uma abordagem probabilística para reconhecer um objeto estruturado em imagens. Nesse cenário, o GER modelo é considerado uma variável aleatória, enquanto uma rotulação de uma imagem de entrada é interpretada como uma potencial observação do modelo. A tarefa de reconhecimento foi então formulada como um problema de otimização, que busca maximizar a probabilidade da observação de acordo com o modelo. O método foi aplicado à modelagem de órgãos abdominais em imagens de ressonância magnética não-contrastadas. Esses órgãos apresentam um arranjo espacial consistente em imagens distintas, além de propriedades de aparência e anatômicas variáveis, o que vem ao encontro da proposta da representação por GER e da abordagem probabilística para o reconhecimento dos órgãos em novas imagens. / The purpose of this thesis was to propose a formalism for the problems of modeling and recognition of a structured object, or a system of structured objects, in images. A structured object is one that may be described in terms of its compound primitive elements and their inherent relations. For instance, an aircraft may be described in terms of the following primitives: right and left wings, fuselage, and cockpit. The relational aspect of structured objects leads these problems to solutions in structural pattern recognition, which describes patterns as primitives and relations. Nevertheless, the variability of primitive elements and of their relations is better modeled by traditional statistical pattern recognition methods. Because of the complementary capabilities of these approaches, the fusion of both has recently been pointed out as a trend in computer vision. To consider these sources of information, the methodology presented herein combines relational cues inherent to a structured object with statistical information learned from a set of object samples. A hybrid model of a structured object is represented by means of a statistical relational graph (SRG). The SRG is a prototype attributed relational graph (ARG) in which nodes represent primitive elements and arcs link nodes representing related primitives. Each node or arc is associated with attributes which are parameters of probability distributions that describe random variables representing primitive or relational attributes. Based on this representation, a probabilistic approach was proposed to tackle the problem of recognizing a structured object in an input image. The model SRG is interpreted as a random variable, whereas a labeling of the input image is considered a potential observation of the model. The recognition task was formulated as the optimization of an objective-function that is actually a probability measure to be maximized. The proposed approach was applied to the modeling of abdominal organs in non-contrasted magnetic resonance images. These organs present consistent spatial arrangement in distinct images, as well as varying appearance and anatomical properties, which meet the principle of the SRG representation and the associated probabilistic recognition scenario.

The diploma thesis deals with the image registration using evolutionary algorithms from metaheuristic optimization techniques which are considered recent and widely used. The frst part of the thesis contains theoretical description of components in image registration and later focuses on the ultrasound images. In that part, the thesis explains chosen evolutionary algorithms. Three optimization methods have been implemented, in particular genetic algorithm, particle swarm optimization and frey algorithm. Chosen similarity metrics for optimization are sum of squared dierences, cosine similarity and correlation coefcient. The main part of thesis includes testing of proposed methods with the evaluation of obtained results. These parameters are later used for optimization of real ultrasound sequences obtained by the contrast imaging.

By using a natural experiment approach and longitudinal national hospital data, this study sheds light on the objective functions of hospitals with different ownership forms by comparing their relative reductions in HH provision after the implementation of the BBA. The empirical findings reveal that for-profit hospitals behave differently as compared to public and private nonprofit hospitals, due to their different operational objectives. While the response of for-profit hospitals is consistent with the profit-maximizer model, both public and private nonprofit ownership types behave consistently in accordance with the model of two-good producers whose objective is to maximize market outputs for meeting the health care needs of the community, given the break-even requirement. This finding provides support for the tax exemption the United States government has granted private nonprofit hospitals. Although the response patterns of the nonprofit ownership types are in general similar, this study found that, contrary to expectation, religious hospitals were more likely than secular nonprofit hospitals to have reduced HH provision after the BBA. Further studies are needed to explore the difference in operational behaviors between these two ownership types. Built on previous related studies and applying a more comprehensive set of independent and control variables with improved data sources, this study is able to examine the effects of certain organizational and market factors on hospital offering of HH care pre-BBA and the change in the provision of HH care in the six years following the implementation of the BBA. Hospital proportion of Medicare patients, hospital size, total profit margin, case mix index, elderly density in the market are found to be positive determinants of a hospital’s likelihood of offering HH care. However, these organizational and market factors, in general, play a non-significant role in influencing hospitals’ changes in HH care provision after the implementation of the BBA. In the study, explanations and implications of these finding are discussed. Finally, potential limitations to this study and opportunities for future research are addressed.

This master´s thesis deals with the registration of ultrasound sequences using evolutionary algorithms. The theoretical part of the thesis describes the process of image registration and its optimalization using genetic and metaheuristic algorithms. The thesis also presents problems that may occur during the registration of ultrasonographic images and various approaches to their registration. In the practical part of the work, several optimization methods for the registration of a number of sequences were implemented and compared.

This thesis deals with the optimization of the structural design of large technology compounds. The main emphasis is placed on the participation of available optimization instruments in the design of supporting structures of these constructions. The introductory part is primarily focused on the optimization itself. In this part are further specified also used optimization methods, computational finite element method, implemented code checks and calculation of cost of construction. The main part is dedicated to application of optimization procedure for the design of steel supporting structure of the auxiliary technological object of thermal power plant. The objective criterium shall then constitute the total cost of construction works along with operating costs. For the solution is used Scia Engineer software together with optimization module Scia Engineer Optimization Toolbox. The whole analysis is presented comprehensively from the description of computational model to results evaluation. The attention is paid to the optimization task settings, technical solution of optimization, optimization methods deployment and during the calculation process (especially to the development of objective function values and desing constraints during the optimization solution).

本論文は第二言語話者の発話を高精度で認識するための音素セットの構成方法に関する研究結果を述べている．本論文では，第二言語話者の発話をネイティブ話者の発話とは異なる音響特徴量の頻度分布を持つ情報源とみなし，これを表現する適切な音素セットを構築する手法を提案している．具体的には，対象とする第二言語と母語との調音位置や調音様式などの類似性に加え，同音異義語の発生による単語識別性能の低下を総合した基準に基づき，最適な音素セットを決定する．提案手法を日本人学生の英語発話の音声認識に適用し，種々の条件下で認識精度の向上を検証した． / This dissertation focuses on the problem caused by confused mispronunciation to improve the recognition performance of second language speech. A novel method considering integrated acoustic and linguistic features is proposed to derive a reduced phoneme set for L2 speech recognition. The customized phoneme set is created with a phonetic decision tree (PDT)-based top-down sequential splitting method that utilizes the phonological knowledge between L1 and L2. The dissertation verifies the efficacy of the proposed method for Japanese English and shows that the feasibility of building a speech recognizer with the proposed method is able to alleviate the problem caused by confused mispronunciation by second language speakers. / 博士(工学) / Doctor of Philosophy in Engineering / 同志社大学 / Doshisha University

The thesis deals the issue of solution of continuous systems by evolutionary computational techniques. Evolutionary computing techniques fall into the field of softcomputing, an advanced metaheuristics optimization that is becoming more and more a method of solving complicated optimization problems with the gradual increase in computing performance of computers. The solution of continuous systems, or the synthesis of continuous control circuits, is one of the areas where these advanced algorithms find their application. When dealing with continuous systems we will focus on regulatory issues. Evolutionary computing can then become a tool not only for optimization of controller parameters but also to design its structure. Various algorithms (genetic algorithm, differential evolution, etc.) can be used to optimize the parameters of the controller, for the design of the controller structurewe usually encounter so called grammatical evolution. However, the use of grammatical evolution is not necessary if appropriate coding is used, as suggested in the presented thesis. The thesis presents a method of designing the structure and parameters of a general linear controller using the genetic algorithm. A general linear regulator is known also as so called polynomial controller, if we encounter the polynomial theory of control. The method of encoding the description of the general linear controller into the genetic chain is crucial, it determines a set of algorithms that are usable for optimization and influence the efficiency of the calculations. Described coding, effective EVT implementation, including multi-criteria optimization, is a key benefit of this work.