[pt] A exploração e desenvolvimento de um campo de petróleo é permeada de incertezas de diferentes naturezas. A incerteza mais básica que o gestor de um portfolio exploratório enfrenta é aquela relativa à existência (ou não) de petróleo em determinado prospecto. Tipicamente, incertezas técnicas tendem a ser reduzidas com investimentos em aquisição de informação, que são exercícios de opções de aprendizagem. Decorrente da estrutura de correlações presentes nos prospectos de um portfolio exploratório, o resultado da perfuração de um poço pioneiro potencialmente irá revelar informações adicionais sobre a probabilidade de existência (ou não) de petróleo em outros prospectos deste mesmo portfolio. Cada poço a ser perfurado pode ser entendido como uma opção de aprendizagem a ser exercida (ou não) a depender da sua probabilidade de sucesso. Neste contexto, um dos fatores determinantes na otimização da campanha exploratória é a escolha da sequência ideal de perfuração de poços. Tal escolha é mais complexa, quão maior for a quantidade e diversidade de prospectos no portfolio. Diante dessa realidade, este trabalho propõe uma modelagem que busca, através de Algoritmos Genéticos, otimizar a sequência de perfurações dos poços e, portanto, o valor do portfolio. O modelo proposto considera as interdependências e as especificidades de cada prospecto e usa como função objetivo, a ser maximizada, o valor presente do líquido (VPL). Opções e aprendizagem são os aspectos-chave por trás do modelo de otimização. O modelo foi avaliado em dez diferentes portfolios exploratórios e, em todos os casos, foi capaz de propor pelo menos uma sequência que apresentasse expressivos ganhos de VPL em relação ao caso-base. / [en] An oil field exploration and development campaign is bounded with different kinds of uncertainty. The most basic one that an E and P portfolio manager deals with is the one related to the existence (or not) of oil in a given prospect. Typically, technical uncertainties are related to learning, and tend to be reduced with investments on information acquisition. From the correlation pattern on the prospects in a given exploratory portfolio, follows that the results from one initial wildcat drilling will, potentially, reveal, additional information about the oil existence (or not) in other prospects in the same geological play. This way, each prospect to be drilled might be understood as a learning option to be exercised (or not) depending on its respective success probability. In such case, one of the main factors on optimizing the exploratory campaign is choosing the ideal drilling sequence. Such choice is more complex, as the quantity and diversity of the prospects increases. Given such background, the present work proposes a model that intends, using Genetic Algorithms, to optimize the drilling sequence and, as a consequence, the total portfolio value. The proposed model considers the interdependencies and each prospect specific aspects and has as an objective function (to be maximizes) the portfolio net present value (NPV). Options and learning are the main aspects underlying the optimization model. The model was evaluated on ten different exploratory portfolios and, in every case, was able to deliver at least one sequence that could represent expressive NPV gains compared to the basic scenario.

published_or_final_version / Statistics / Doctoral / Doctor of Philosophy

No description available.

The purpose of this thesis research was to examine the dynamic relationship between climate change and tourism, with a direct focus on Churchill, Manitoba’s polar bear viewing industry. This unique tourism industry and the polar bears it depends on, are experiencing the negative effects of climate change due to warmer temperatures and melting sea ice, which significantly impacts the health, appearance, and prevalence of polar bears on display for tourists. Not only is this tourism industry affected by climate change, it also contributes to the ongoing changes of climatic conditions. This is due to the dependence of fossil fuel energy used for transportation, accommodation, and activities which directly contributes to the release of greenhouse gas emissions and thus to global climate change. Emissions from tourism has increased by 3% over the last 10 years, largely as a result of the accessibility and affordability of air travel, the most energy intensive form of transportation (Lenzen et al., 2018; UNWTO-UNEP-WMO, 2008). It has been suggested that in response to the increase in the demand to travel, the tourism industry should take a leadership role to reduce their total greenhouse gas emissions in an effort to decrease the impact of climate change. In this study, a visitor survey was conducted during four weeks of Churchill’s 2018 polar bear viewing season (October 16 to November 16). The aim of the survey was to: 1) estimate greenhouse gas emissions from polar bear viewing tourists and the polar bear viewing industry; 2) identify tourists’ awareness of the impacts of climate change (to and from tourism activities); 3) understand tourist’s climate-related travel motivations, and 4) identify tourists’ opinions on climate change mitigation strategies. Visitor surveys were hand- distributed at the Churchill Northern Studies Centre and at the Churchill Airport to tourists who had participated on a polar bear viewing tour. Surveys were analyzed and compared with the results from similar studies (Dawson et al., 2010 and Groulx, 2015) to identify the changing trends in greenhouse gas emissions, travel motivations, tourists’ knowledge of climate change, and acceptance of climate change mitigation strategies. Similar to trends observed 10 years ago, emissions from polar bear viewing tourists are 3-34 times higher than the average global tourist experience. Tourists’ awareness about climate change has stayed relatively consistent, despite the topic of climate change having received increased attention globally. Tourists recognize that climate change is happening and that it is human induced however, there is still a lack of understanding of how air travel is a contributor to climatic change. Although briefly mentioned in some participant’s responses, the main motivation was not to see a polar bear before it disappeared from the wild. The majority of tourists identified they were traveling to Churchill simply for the opportunity to see a polar bear. Additional motivators were photography, the Northern Lights, and for the opportunity to see other Arctic animals. The climate change mitigation strategies that tourists believed to be the most effective to reduce emissions were educational programs and transportation alternatives (such as taking the train- which was not an option at the time of study due to a rail line shutdown). This research contributes to the existing knowledge about tourism and climate change and provides a current analysis of Churchill’s polar bear viewing industry, enabling a comparison between findings from another study conducted over ten years ago. This research also makes conclusions about climate change mitigation strategies that might be effective for Churchill’s tourism industry to reduce their impact on the environment.

[ Abstract ] This research is for the purpose of to Kaoshiung south funds of utilization and the development tendency the area someone public industry high-level vocational school, makes the partial analyses and the research. The discussion affects this school funds budget disposition factor with whether has the decision-making by chance and of relativity utilization of and the social pulsation the funds. Disposition of in view of the education funds and effectiveness proposed the research suggestion, will be advantageous to future establishes reference the long-term education resources plan as the school, the display education resources effectiveness maximization. Front in order to achieve states the goal and studies budget, the final accounts material the school using the Kaoshiung municipal government, with same economic activity target and so on time economical growth rate, each kind of stock price index, labor productivity index, using the number of times percentage analysis, the mean value and the standard difference analysis, to examine and statistical method analysis and multiple regression analysis tests each hypothesis. Specifically says below, this research obtains the conclusion: (1) School frequently disburses the funds influence factor, from to the student counts for guides carries on the plan funds, this research real diagnosis demonstrated has the high relativity for to reveal the factor with the literature research discussion conclusion is consistent, but the Kaoshiung municipal government frequently budgets also for reveals the factor, obviously the public school frequently disburses mainly admires the municipal government to allocate funds to take from a surplus to supply an insufficiency, frequently disburses take the student counts as the guidance, carries on frequently disburses the plan pattern, basically is the direction which the present stage should maintain. (2) Capital funds counts take the student as the explanation variable, is possible in this research institute supposition to affect in the variable to demonstrate school of capital outlay investment the research changes certain part and the student number presents the reverse relations. (3) The capital outlay makes the analysis by the detail material, the information branch and the information equipment funds possibly explains the variable, has the student to count, the electronic stock price index all for reveals the negative direction explanation factor. (4) Is possible by the school total funds analysis to affect the variable, for reveals with the teaching and administrative staff number to, change influence possible factor and the teaching and administrative staff number the total funds have to the relativity, but the student number reveals the negative direction change, has the difference with the universal cognition, after or is most mainly included the capital outlay the total funds, causes the student to count this variable to make the regression analysis to the total funds to present reverse reveals the influence. (5) The student counts the growth, with the labor production index, the economical growth index changes the movement explanation variable, finally demonstrated the student counts the change, in certain degrees by the labor production index, the economical growth index is possibly changed two factors to explain. (6) Practice equipment budget various branches capital disbursement, studied the school still to have the many branches other student to practice the equipment unit cost to reveal is outdoing other branches, discovered possibly had the decision-making in this aspect school by chance.

Elementary students¡¦ participation in activities is an important issue. By participating in activities, students become socialization; learn the optimistic attitude toward people and environment and develop their personality. This study was assumed that elementary students not only participate in school activities, but also in extra curricula activities. The degree of participation in both activities depends on the family background, and shapes individual life chance in the future. The data focuses on four elementary school in residential district and industrial estate, located in Yongkang City, Tainan County, and sampling randomly 310 students from the senior students¡]sixth grade¡^to analyze. These below are the analysis¡G 1. The variable of school and extra curricula activities has significant correlation with variables of educational expectancy and the life chance. 2. This study regards the level of Father¡¦s education and occupation as a family¡¦s socio-economic status. It founds that the higher the family¡¦s socio-economic status, the better the students¡¦ educational expectancy. 3. Variable of the level of Father¡¦s education and occupation makes significant correlation with extra curricula activities. ¡]1¡^The higher the family¡¦s socio-economic status is, the more frequency of children¡¦s participation extra curricula activities is. ¡]2¡^The higher the family¡¦s socio-economic status is, the longer the children¡¦s participation in extra curricula activities is. ¡]3¡^According to these two point above, it founds that a family¡¦s socio-economic status makes great influence in students¡¦ participation in extra curricula activities. 4. By statistic regression, it shows that a family¡¦s socio-economic status is the biggest influence to students¡¦ educational expectancy. This study founds that whether elementary students participate in activities or not, makes great influence to life chance in the future. However, a family¡¦s socio-economic status makes the inequality of the chance. It is proposed that socialist, educationist, and the policy-maker should make efforts to eliminate the restriction of inequality, and build a friendly environment for students to learn by participating in any activities. Consequently, the equal chance will promote students¡¦ self and social competition ability, and make them develop great life chance.

We consider joint chance-constrained programs with random lefthand sides. The motivation of this project is that this class of problem has many important applications, but there are few existing solution methods. For the most part, we deal with the subclass of problems for which the underlying parameter distributions are discrete. This assumption allows the original problem to be formulated as a deterministic equivalent mixed-integer program. We rst approach the problem as a mixed-integer program and derive a class of optimality cuts based on irreducibly infeasible subsets of the constraints of the scenarios of the problem. The IIS cuts can be computed effciently by means of a linear program. We give a method for improving the upper bound of the problem when no IIS cut can be identifi ed. We also give an implementation of an algorithm incorporating these ideas and finish with some computational results. We present a tabu search metaheuristic for fi nding good feasible solutions to the mixed-integer formulation of the problem. Our heuristic works by de ning a sufficient set of scenarios with the characteristic that all other scenarios do not have to be considered when generating upper bounds. We then use tabu search on the one-opt neighborhood of the problem. We give computational results that show our metaheuristic outperforming the state-of-the-art industrial solvers. We then show how to reformulate the problem so that the chance-constraints are monotonic functions. We then derive a convergent global branch-and-bound algorithm using the principles of monotonic optimization. We give a finitely convergent modi cation of the algorithm. Finally, we give a discussion on why this algorithm is computationally ine ffective. The last section of this dissertation details an application of joint chance-constrained stochastic programs to a vaccination allocation problem. We show why it is necessary to formulate the problem with random parameters and also why chance-constraints are a good framework for de fining an optimal policy. We give an example of the problem formulated as a chance constraint and a short numerical example to illustrate the concepts.

This dissertation is centered on problems within the history and philosophy of biology. The project identifies the philosophical roots of the current ecological movement and shows how a version of philosophical naturalism might be put to use within contemporary ethical issues in biology, and aid in the development of research programs. The approach is historically informed, but has application for current dilemmas. The traditions from which I primarily draw include classical American philosophy, particularly C.S. Peirce and John Dewey, as well as thinkers associated with the German Naturphilosophie movement, such as Goethe and Schopenhauer. There are deep, but often overlooked, resonances between these seemingly disparate traditions and contemporary biology that are located in the conflict between the developing organism and the ever-fluctuating environment. The dissertation makes the case for a shared description of nature among these traditions and proposes applications to burgeoning contemporary ecological interpretations of issues such as hybridization and epigenetics.

Thesis (Ph. D.)--University of Oregon, 2008. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 208-216). Also available online in Scholars' Bank; and in ProQuest, free to University of Oregon users.

Thesis (Ph. D.)--University of Stellenbosch, 2004. / Includes bibliographical references. Also available via the Internet.