Made available in DSpace on 2015-04-22T22:16:04Z (GMT). No. of bitstreams: 1 Jose Nazareno Vieira Gomes.pdf: 449205 bytes, checksum: ed034dfcd18d705f7d20d12e963faffc (MD5) Previous issue date: 2008-09-15 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Consider immersion (Expressão Matemática) dimensional manifold Mn in a manifold of constant secctional curvature c. Let N(x) be the first normal space of f in x 2 M, that is the subspace of the normal space that is generate to image of second form fundamental of f in x. We say that we can reduce the codimension of f to k, with (Expressão Matemática), if exists a submanifold L of Qc (n + k)-dimensional totally geodesic such that (Expressão Matemática), and f is 1-1-regular if the first normal space have constant dimension 1. The objective of this work is to give a detailed exhibition of results obtained by Lúcio Rodriguez and Renato Tribuzy in "Reduction of Codimension of Regular Immersions", published in Mathematische Zeitschrift in the year of 1984, that permit to reduce the codimension of 1-1-regular. / Considere uma imersão (Expressão Matemática) de uma variedade n-dimensional Mn em uma variedade de curvatura seccional constante c. Seja N(x) o primeiro espaço normal de f em x 2 M, isto é, o subespaço do espaço normal que é gerado pela imagem da segunda forma fundamental de f em x. Diz-se que se pode reduzir a codimensão de f para k, com (Expressão Matemática), se existe uma subvariedade (n+k)-dimensional L de Qc totalmente geodésica e tal que (Expressão Matemática) regular se o primeiro espaço normal tem dimensão constante 1. O objetivo deste trabalho é dar uma exposição detalhada de resultados obtidos por Lúcio Rodriguez e Renato Tribuzy em "Redução de Codimensão de Imersões Regulares", publicado em Mathematische Zeitschrift no ano de 1984, que permitem reduzir a codimensão de imersões 1-1-regulares.

Made available in DSpace on 2015-04-22T22:16:13Z (GMT). No. of bitstreams: 1 Ana Acacia Pereira Valente.pdf: 221896 bytes, checksum: f7a5ffc2646f76d06002549f557bd363 (MD5) Previous issue date: 2003-12-19 / The work of this essay is to make a clear on detailed exposition of the two theorems of the article of Lúcio Rodriguez and Renato Tribuzy on the Reduction of Codimension of Regular Immersions in the space of constant curvature c. We show that if M is a compact and connected manifold, of dimension n, and is an immersion (formula) regular, that is, when the first normal space N generated by image of the second fundamental form has constant dimension 1, then we can reduce the codimension of the immersion to 1. Other result important in the work show that if M is complete, connected with non-negative Ricci curvature, then f is a cylinder over a curve our we can reduce the codimension to 1 and f(M) is the boundary of a convex set in an a±ne subspace of (formula). / Este trabalho tem como finalidade apresentar uma exposição clara e detalhada de dois dos teoremas apresentados no artigo de Lúcio Rodriguez e Renato Tribuzy sobre Redução de Codimensão de Imersões Regulares em Espaços de Curvatura Constante c. Mostra-se que se tivermos uma variedade compacta e conexa M, de dimensão n, e uma imersão (formula) regular, isto é, quando a dimensão do primeiro espaço normal N gerado pelas imagens da segunda forma fundamental tem dimensão constante igual a 1, então podemos reduzir a codimensão da imersão para 1. Outro resultado importante neste trabalho é o fato de que se a variedade é apenas completa, conexa e com curvatura de Ricci não-negativa, então a imersão será um cilindro sobre uma curva, do contrário, podemos reduzir a codimensão para 1 e nossa imersão será o bordo de um corpo convexo em um subespaço (formula).

The objective of this study has been to answer the question of finding ways to improve the quality of database. There exists a lot of problems of the data stored in the database, like missing or spelling errors. To deal with the dirty data in the database, this study adopts the conditional functional dependencies and regular expressions to detect and correct data. Based on the former studies of data cleaning methods, this study considers the more complex conditions of database and combines the efficient algorithms to deal with the data. The study shows that by using these methods, the database’s quality can be improved and considering the complexity of time and space, there still has a lot of things to do to make the data cleaning process more efficiency.

Web Information Extraction (WIE) is the discipline dealing with the discovery, processing and extraction of specific pieces of information from semi-structured or unstructured web pages. The World Wide Web comprises billions of web pages and there is much need for systems that will locate, extract and integrate the acquired knowledge into organisations practices. There are some commercial, automated web extraction software packages, however their success comes from heavily involving their users in the process of finding the relevant web pages, preparing the system to recognise items of interest on these pages and manually dealing with the evaluation and storage of the extracted results. This research has explored WIE, specifically with regard to the automation of the extraction and validation of online training information. The work also includes research and development in the area of automated Web Information Retrieval (WIR), more specifically in Web Searching (or Crawling) and Web Classification. Different technologies were considered, however after much consideration, Naïve Bayes Networks were chosen as the most suitable for the development of the classification system. The extraction part of the system used Genetic Programming (GP) for the generation of web extraction solutions. Specifically, GP was used to evolve Regular Expressions, which were then used to extract specific training course information from the web such as: course names, prices, dates and locations. The experimental results indicate that all three aspects of this research perform very well, with the Web Crawler outperforming existing crawling systems, the Web Classifier performing with an accuracy of over 95% and a precision of over 98%, and the Web Extractor achieving an accuracy of over 94% for the extraction of course titles and an accuracy of just under 67% for the extraction of other course attributes such as dates, prices and locations. Furthermore, the overall work is of great significance to the sponsoring company, as it simplifies and improves the existing time-consuming, labour-intensive and error-prone manual techniques, as will be discussed in this thesis. The prototype developed in this research works in the background and requires very little, often no, human assistance.

In this thesis, we aim at a quantitative understanding of extreme risks. We use heavy-tailed distribution functions to model extreme risks, and use various tools, such as copulas and MRV, to model dependence structures. We focus on modeling as well as quantitatively estimating certain measurements of extreme risks. We start with a credit risk management problem. More specifically, we consider a credit portfolio of multiple obligors subject to possible default. We propose a new structural model for the loss given default, which takes into account the severity of default. Then we study the tail behavior of the loss given default under the assumption that the losses of the obligors jointly follow an MRV structure. This structure provides an ideal framework for modeling both heavy tails and asymptotic dependence. Using HRV, we also accommodate the asymptotically independent case. Multivariate models involving Archimedean copulas, mixtures and linear transforms are revisited. We then derive asymptotic estimates for the Value at Risk and Conditional Tail Expectation of the loss given default and compare them with the traditional empirical estimates. Next, we consider an investor who invests in multiple lines of business and study a capital allocation problem. A randomly weighted sum structure is proposed, which can capture both the heavy-tailedness of losses and the dependence among them, while at the same time separates the magnitudes from dependence. To pursue as much generality as possible, we do not impose any requirement on the dependence structure of the random weights. We first study the tail behavior of the total loss and obtain asymptotic formulas under various sets of conditions. Then we derive asymptotic formulas for capital allocation and further refine them to be explicit for some cases. Finally, we conduct extreme risk analysis for an insurer who makes investments. We consider a discrete-time risk model in which the insurer is allowed to invest a proportion of its wealth in a risky stock and keep the rest in a risk-free bond. Assume that the claim amounts within individual periods follow an autoregressive process with heavy-tailed innovations and that the log-returns of the stock follow another autoregressive process, independent of the former one. We derive an asymptotic formula for the finite-time ruin probability and propose a hybrid method, combining simulation with asymptotics, to compute this ruin probability more efficiently. As an application, we consider a portfolio optimization problem in which we determine the proportion invested in the risky stock that maximizes the expected terminal wealth subject to a constraint on the ruin probability.

Implementation of federally mandated classroom inclusion of students with disabilities (SWDs) in the United States is inconsistent. Research has been limited on how teachers implement inclusion in classrooms, which has prevented systemwide improvements of inclusion practices. The purpose of this basic qualitative study was to describe the circumstances and experiences of regular and special education teachers in 3rd to 6th grade inclusion classes. The theory of organizational learning served as the conceptual framework for the study. Data were collected in interviews with 7 regular education teachers (RETs) and 5 special education teachers (SETs) from 3 public school districts in a south-central U.S. state. Data were analyzed using open coding to identify themes and patterns. Results indicated that SETs served SWDs from multiple classes and sometimes from multiple grades rather than following 1 student throughout the day. Further, RETs had students with and without disabilities from up to 7 different grade levels in their inclusion classrooms. Findings also revealed that none of the participants engaged in collaborative content planning. Almost all participants expressed the need for additional teachers to reduce the teacher-to-student ratio and for more training for RETs to support inclusion of SWDs in their classes. Findings may provide information to leaders at the building, district, regional, state, and legislative levels regarding how inclusion can be improved in classrooms, including how systemic change in public school systems may be implemented.

Many historical documents are rich in genealogical facts. Extracting these facts by hand is tedious and almost impossible considering the hundreds of thousands of genealogically rich family-history books currently scanned and online. As one approach for helping to make the extraction feasible, we propose GreenFIE—a "Green" Form-based Information-Extraction tool which is "green" in the sense that it improves with use toward the goal of minimizing the cost of human labor while maintaining high extraction accuracy. Given a page in a historical document, the user's task is to fill out given forms with all facts on a page in a document called for by the forms (e.g. to collect the birth and death information, marriage information, and parent-child relationships for each person on the page). GreenFIE has a repository of extraction patterns that it applies to fill in forms. A user checks the correctness of GreenFIE's form filling, adds any missed facts, and fixes any mistakes. GreenFIE learns based on user feedback, adding new extraction rules to its repository. Ideally, GreenFIE improves as it proceeds so that it does most of the work, leaving little for the user to do other than confirm that its extraction is correct. We evaluate how well GreenFIE performs on family history books in terms of "greenness"—how much human labor diminishes during form filling, while simultaneously maintaining high accuracy.

Let n be a positive integer. A Latin square of order n is an n×n array L such that each element of some n-set occurs in each row and in each column of L exactly once. It is well-known that one may construct a 4-class association scheme on the positions of a Latin square, where the relations are the identity, being in the same row, being in the same column, having the same entry, and everything else. We describe the subconstituent (Terwilliger) algebras of such an association scheme. One also may construct several strongly regular graphs on the positions of a Latin square, where adjacency corresponds to any subset of the nonidentity relations described above. We describe the local spectrum and subconstituent algebras of such strongly regular graphs. Finally, we study various notions of isomorphism for subconstituent algebras using Latin squares as examples.

Sport events and attractions which encourage both participants and spectators are seen as significant contributors to the tourism economy (Delpy, 1998; Glyptis, 1991; Standeven & DeKnop, 1999). Further, Gratton and Taylor (2000) note that sport related travel accounts for 7% of total expenditure on sport. To date, the main focus of event sport tourism research has been on the economic impact of large-scale sport events (Burgan & Mules, 1992; Crompton, 1995; Mules & Faulkner, 1996; Walo, Bull, & Breen, 1996). However, Higham (1999) posits that smaller scale events such as regular season games may be of greater benefit to the host community as these events are hosted within existing infrastructure and therefore limit the need for public expenditure. However, fans who travel to regular season competition are a market segment that has been largely ignored by both sport and tourism marketers. Sport marketers have focused on home game attendance, media viewership and product purchases, while tourism marketers have focused on leveraging the destination. Anecdotal evidence suggests that fans who travel organise a substantial proportion of their discretionary time and income around this activity. Recent research by Gibson, Willming and Holdnak (2002, 2003) has begun to understand the behaviours of sport fans who travel to home games. This study seeks to understand the behaviours and experiences of those who travel to attend away games. In particular the study asks: What motivates fans to travel to follow professional sport teams, what experiences fans have and seek during the travel, and what place does travelling to follow a sport team have in the overall consumption behaviour of sport fans. This study examined the motives and experiences of six fan groups travelling interstate to follow their Australian Football League (AFL) team in the 2001 season. As the behaviours and experiences of those who travel to follow sport teams have not previously been explored, exploratory analysis using an iterative process of constant comparison between data colleted from the research setting and the existent literature. Using this method the researcher was able to describe the social world under investigation without preconceived hypotheses. The researcher travelled interstate with each fan group, and collected data via participant observation and interviews with key informants. Data were coded using standard protocols for analysis of qualitative data (Spradley, 1980). The researcher read through the transcripts and field notes and coded all phrases and opinions from the manuscript. Data were analysed through the process of data reduction, selective sampling of the literature, and selected sampling of the data (Stern, 1980). From the initial codes, data reduction identified core variables and emergent themes. Through this grounded theory methodology, a conceptual model was developed which illustrates the motives and experiences of those who travel to follow professional sport teams. Three distinct types of groups were identified, each garnering a distinctive sport tourism experience. The groups identified were: supporter groups, long-term travel groups, and temporary travel groups. While travel to follow the team is the stated rationale for all three groups, the game experience for each is substantially different, four major themes emerged which distinguished the groups and the experiences that they had. These were: (1) group structure, (2) trip characteristics, (3) socialisation, and (4) game experience and reaction to game outcome. Each type of group was found to have a distinct group structure, communication pattern, but differed in terms of the objects to which they identified. Findings suggest that sport fans do not necessarily identify with the team or related object, but can identify with a smaller social group, which has a shared interest in the team. These elements of group structure and point of identification were found to have a reciprocal relationship with various travel elements that were utilised by each group including the mode of transport, temporal elements, choice of destination, and activities at the destination. In particular, the travel elements were chosen so that each group type could best express and experience that which is core to each group. Further analysis suggested that the experience of each of the groups was influenced by the continual development of the group both before and during the travel experience. For the supporter groups and long-term travel groups, rituals, symbols, and folklore played a key role in the experience. These elements of performance were used to continually shape and interpret the travel experience. One would expect that the game would have elevated importance, as it is the activity that legitimates each group. However, the on-field game did not have prime importance. Instead the different points of identification of each group were used as a basis through which the game was experienced. Key implications for sport and tourism marketing suggest that the sport tourism experience is more than an experience of place or an experience of watching the sport. Identification with a small social group is sufficient to generate travel to follow a team. By providing a setting which immerses participants in a particular identity for a prolonged period of time, the act of travelling itself can create a social climate that encourages participants to undertake the trip week after week, and form deep connection to the team. Implications for practice and future research directions are also discussed.

Predicting customers’ intention to purchase products online is an important issue. This thesis aims to understand how online shopping decision is determined by individual’s intention to buy via Internet and his/her attitude toward e-purchase. This study by integrating the Theory of Reasoned Action (TRA) with the Technology Acceptance Model (TAM), attempts to understand how website usefulness and ease of use, as well as customers’ attitude toward online shopping, influence purchase intention influence the online purchase. Those two models adopted in an online environment were used to analyze the outcome of the survey among Polish e-shoppers. By adopting the idea of regular and heavy Internet users, this study tries to differentiate the online shopping behavior in those two groups. The findings of the thesis have been found to be partially consistent with both models. However the difference between heavy and regular Internet users in frequency of buying online has not been confirmed.