Thesis (Ph.D.)--Ohio University, June, 2008. / Title from PDF t.p. Includes bibliographical references.

Thesis (M.A.)--University of Notre Dame, 2006. / Thesis directed by Dawn M. Gondoli for the Department of Psychology. "July 2006." Includes bibliographical references (leaves 57-60).

Thesis (Ph. D.) University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on month August 3, 2007) Includes bibliographical references.

Large dams represent complex social-ecological systems, perhaps the most complicated projects among large infrastructures. Nowadays, developing and developed countries consider large dams as a viable solution to provide low-cost energy production and flood control for agriculture production. However, the debate about dams is generally focused on technical arrangements, lacking of a holistic perspective of analysis, while their effects may be disruptive for a wider number of factors. The present paper proposes to study large dams within the theory of common-pool resources, focusing on the relation between water security and sustainability. The use of a social-ecological framework facilitates a dynamic analysis among different variables of large dams. What is more, it permits a cross-scale analysis, enabling one to understand the extreme complexity of social-ecological changes in a considered system. This research will focus on the Ethiopian large dam Gibe III, predicted to start functioning at the end of this year. It is already altering the downstream conditions of Omo River and Lake Turkana, shared by Ethiopia and Kenya, posing a threat to the livelihoods of thousand people. However, the current discussion about it still appears limited to technical solutions to the dam implementation. Arguing the opposite, the social-ecological framework enables one to include information sharing, climate change and collective-choice rules as important elements to be considered to bring the discussion at a broader level of understanding. From the analysis of Ethiopia, it is found that large dams cannot alone be the answer to water security if they are not connected to more vast social-economic reforms. The paper argues that the interpretation of large dams must be considered as part of the broader social, ecological and politico-economic situation, transcending from the mere local situation. The overall picture is not whether not to build them or not, as there is not a real choice, but how to foster instruments of analysis that preserve the environment and societies, while defeating poverty.

Depuis quelques années, l’évolution des techniques d’acquisition a entraîné une généralisation de l’utilisation d’objets 3D très dense, représentés par des nuages de points de plusieurs millions de sommets. Au vu de la complexité de ces données, il est souvent nécessaire de les analyser pour en extraire les structures les plus pertinentes, potentiellement définies à plusieurs échelles. Parmi les nombreuses méthodes traditionnellement utilisées pour analyser des signaux numériques, l’analyse dite scale-space est aujourd’hui un standard pour l’étude des courbes et des images. Cependant, son adaptation aux données 3D pose des problèmes d’instabilité et nécessite une information de connectivité, qui n’est pas directement définie dans les cas des nuages de points. Dans cette thèse, nous présentons une suite d’outils mathématiques pour l’analyse des objets 3D, sous le nom de Growing Least Squares (GLS). Nous proposons de représenter la géométrie décrite par un nuage de points via une primitive du second ordre ajustée par une minimisation aux moindres carrés, et cela à pour plusieurs échelles. Cette description est ensuite derivée analytiquement pour extraire de manière continue les structures les plus pertinentes à la fois en espace et en échelle. Nous montrons par plusieurs exemples et comparaisons que cette représentation et les outils associés définissent une solution efficace pour l’analyse des nuages de points à plusieurs échelles. Un défi intéressant est l’analyse d’objets 3D acquis dans le cadre de l’étude du patrimoine culturel. Dans cette thèse, nous nous étudions les données générées par l’acquisition des fragments des statues entourant par le passé le Phare d’Alexandrie, Septième Merveille du Monde. Plus précisément, nous nous intéressons au réassemblage d’objets fracturés en peu de fragments (une dizaine), mais avec de nombreuses parties manquantes ou fortement dégradées par l’action du temps. Nous proposons un formalisme pour la conception de systèmes d’assemblage virtuel semi-automatiques, permettant de combiner à la fois les connaissances des archéologues et la précision des algorithmes d’assemblage. Nous présentons deux systèmes basés sur cette conception, et nous montrons leur efficacité dans des cas concrets. / Over the last decades, the evolution of acquisition techniques yields the generalization of detailed 3D objects, represented as huge point sets composed of millions of vertices. The complexity of the involved data often requires to analyze them for the extraction and characterization of pertinent structures, which are potentially defined at multiple scales. Amongthe wide variety of methods proposed to analyze digital signals, the scale-space analysis istoday a standard for the study of 2D curves and images. However, its adaptation to 3D dataleads to instabilities and requires connectivity information, which is not directly availablewhen dealing with point sets.In this thesis, we present a new multi-scale analysis framework that we call the GrowingLeast Squares (GLS). It consists of a robust local geometric descriptor that can be evaluatedon point sets at multiple scales using an efficient second-order fitting procedure. We proposeto analytically differentiate this descriptor to extract continuously the pertinent structuresin scale-space. We show that this representation and the associated toolbox define an effi-cient way to analyze 3D objects represented as point sets at multiple scales. To this end, we demonstrate its relevance in various application scenarios.A challenging application is the analysis of acquired 3D objects coming from the CulturalHeritage field. In this thesis, we study a real-world dataset composed of the fragments ofthe statues that were surrounding the legendary Alexandria Lighthouse. In particular, wefocus on the problem of fractured object reassembly, consisting of few fragments (up to aboutten), but with missing parts due to erosion or deterioration. We propose a semi-automaticformalism to combine both the archaeologist’s knowledge and the accuracy of geometricmatching algorithms during the reassembly process. We use it to design two systems, andwe show their efficiency in concrete cases.

Um mosaico é o conjunto de fotos de uma determinada área, recortadas e montadas técnica e artísticamente, de forma a dar a impressão de que todo o conjunto é uma única fotografia. No caso de fotografias aéreas, sua utilização soluciona o problema da necessidade de se retratar uma área de interesse mais extensa do que o campo de cobertura das lentes da câmera utilizada. O foco deste trabalho é a criação automática de mosaicos buscando encontrar a posição real de um conjunto de imagens imagens adquiridas em baixa altitude, de baixa escala, em relação à um Mapa de Base, de escala maior, realizando, assim, uma correlação entre imagens de escalas diferentes. Este problema é abordado por técnicas de análise multi-escala, mais precisamente, pela utilização de filtros de Gabor. A metodologia desenvolvida utiliza um banco de filtros de Gabor aplicado sobre uma imagem de referência de modo que, a partir da aplicação destes filtros sobre a mesma, seja possível gerar um processo automático de geração do mosaico para o restante do conjunto de imagens. Experimentos realizados utilizando o método proposto demonstram a eficácia do mesmo para imagens com texturas de orientação marcante, como o caso de imagens aéreas de plantação de eucaliptos / A mosaic is a set of pictures of a given area, technically and artistically cut and ?glued? together, giving the impression that the entire set resembles a single picture. For aerial photography, the use of mosaics solves the problem of imaging an area of interest whose dimension is much larger than that covered by the majority of the cameras available. This work focuses on the automatic creation of mosaics and aims to compute the real position of a set of images acquired at low altitudes (lower scale), in relation with a base map larger scale), by correlating images in different scales. Multi-scale analysis techniques, in particular, the Gabor filters, constitute an approach to this problem. The proposed methodology uses a bank of Gabor filters applied over a reference image in a way that an automatic process of mosaic generation, with the remaining set of images, could be carried out. Experiments have shown the efficiency of the proposed technique especially for images with clear textural orientation, for example, the case of aerial photographs of eucalyptus plantations

The purpose of this study was to: (a) develop a comprehensive plan consisting of a series of logical steps based upon recommendations derived from psychometric, measurement, and research literature and utilize the plan to develop a Likert-type scale to provide valid and reliable measures of the attitude of preservice and inservice elementary school teachers toward computers; (b) administer the developed scale to selected preservice elementary school teachers; and (c) investigate relationships between attitude toward computers and selected teacher variables. The comprehensive plan consisted of the following steps: (a) develop theory of construction, (b) establish conceptual framework, (c) create item pool, (d) develop trial scale, (e) administer trial scale, (1) conduct item analysis, (g) select items, (h) construct final scale, (i) test for homogeneity, (j) determine reliability, (k) test for unidimensionality, (l) administer final scale, and (m) infer validity. The plan was utilized to develop the Evans Scale for Computer Attitude (ESCA). Validity was inferred utilizing construct-related evidence, which included the manner in which the scale was developed, studies of scale internal structure, prediction and conformation of a general factor, replication of factor structure, relationship of scale scores to nontest variables, relationship of scale scores to similar and dissimilar constructs, comparison of scores with experimental intervention, comparison of known-group responses. An alpha reliability coefficient was found to be 0.96 on two occasions. It was concluded that: (a) the ESCA provided valid and reliable measures of the computer attitude of preservice and inservice teachers at the elementary school level, (b) the comprehensive plan was effective for the development of a Likert-type scale for measuring the attitude toward computers of preservice and inservice teachers at the elementary school level, (c) preservice teachers in the Masters of Arts in Teaching Program (MAT) in Elementary Education at Oregon State University as a group had positive attitude toward computers, and (c) computer attitude of elementary MAT preservice teachers was significantly related in a positive direction with computer experience and in a negative direction with age. / Graduation date: 1995

published_or_final_version / Medicine / Doctoral / Doctor of Philosophy

An indoor environment could be defined by a complex layout in a compact space. Since mobile robots can be used as substitute for human beings to access harmful and inaccessible locations, the research of autonomous indoor navigation has attracted much interest. In general, a mobile robot navigates in an indoor environment where acquired data are limited. Furthermore, sensor measurements may contain errors in a number of situations. Therefore, the complexity of indoor environment and ability of sensors have determined that it is an insufficient to merely compute with data. This thesis presents a new rough-fuzzy approach to perception-based computing for an indoor navigation algorithm. This approach to perceptual computing is being developed to store, analyze and summarize existing experience in given environment so that the machine is able to detect current situation and respond optimally. To improve uncertainty reasoning of fuzzy logic control, a rough set theory is integrated to regulate inputs before applying fuzzy inference rules. The behaviour extraction is evaluated and adjusted through entropy-based measures and multi-scale analysis. The rough-fuzzy based control algorithm aims to minimize overshoot and optimize transient-state period during navigation. The proposed algorithm is tested through simulations and experiments using practical common situations. The performance is evaluated with respect to desired path keeping and transient-state adaptability.

Thesis (Ph.D.)--University of Tulsa, 1993. / Includes bibliographical references (leaves 86-92).