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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Making decisions about screening cargo containers for nuclear threats using decision analysis and optimization

Dauberman, Jamie 06 August 2010 (has links)
One of the most pressing concerns in homeland security is the illegal passing of weapons-grade nuclear material through the borders of the United States. If terrorists can gather the materials needed to construct a nuclear bomb or radiological dispersion device (RDD, i.e., dirty bomb) while inside the United States, the consequences would be devastating. Preventing plutonium, highly enriched uranium (HEU), tritium gas or other materials that can be used to construct a nuclear weapon from illegally entering the United States is an area of vital concern. There are enormous economic consequences when our nation's port security system is compromised. Interdicting nuclear material being smuggled into the United States on cargo containers is an issue of vital national interest, since it is a critical aspect of protecting the United States from nuclear attacks. However, the efforts made to prevent nuclear material from entering the United States via cargo containers have been disjoint, piecemeal, and reactive, not the result of coordinated, systematic planning and analysis. Our economic well-being is intrinsically linked with the success and security of the international trade system. International trade accounts for more than thirty percent of the United States economy (Rooney, 2005). Ninety-five percent of international goods that enter the United States come through one of 361 ports, adding up to more than 11.4 million containers every year (Fritelli, 2005; Rooney, 2005; US DOT, 2007). Port security has emerged as a critically important yet vulnerable component in the homeland security system. Applying game theoretic methods to counterterrorism provides a structured technique for defenders to analyzing the way adversaries will interact under different circumstances and scenarios. This way of thinking is somewhat counterintuitive, but is an extremely useful tool in analyzing potential strategies for defenders. Decision analysis can handle very large and complex problems by integrating multiple perspectives and providing a structured process in evaluating preferences and values from the individuals involved. The process can still ensure that the decision still focuses on achieving the fundamental objectives. In the decision analysis process value tradeoffs are evaluated to review alternatives and attitudes to risk can be quantified to help the decision maker understand what aspects of the problem are not under their control. Most of all decision analysis provides insight that may not have been captured or fully understood if decision analysis was not incorporated into the decision making process. All of these factors make decision analysis essentially to making an informed decision. Game theory and decision analysis both play important roles in counterterrorism efforts. However, they both have their weaknesses. Decision analysis techniques such as probabilistic risk analysis can provide incorrect assessments of risk when modeling intelligent adversaries as uncertain hazards. Game theory analysis also has limitations. For example when analyzing a terrorist or terrorist group using game theory we can only take into consideration one aspect of the problem to optimize at a time. Meaning the analysis is either analyzing the problem from the defenders perspective or from the attacker’s perspective. Parnell et al. (2009) was able to develop a model that simultaneously maximizes the effects of the terrorist and minimizes the consequences for the defender. The question this thesis aims to answer is whether investing in new detector technology for screening cargo containers is a worthwhile investment for protecting our country from a terrorist attack. This thesis introduces an intelligent adversary risk analysis model for determining whether to use new radiological screening technologies at our nation’s ports. This technique provides a more realistic risk assessment of the true situation being modeled and determines whether it is cost effective for our country to invest in new cargo container screening technology. The optimal decision determined by our model is for the United States to invest in a new detector, and for the terrorists to choose agent cobalt-60, shown in Figure 18. This is mainly due to the prominence of false alarms and the high costs associated with screening all of these false alarms, and we assume for every cargo container that sounds an alarm, that container is physically inspected. With the new detector technology the prominence of false alarms decreases and the true alarm rate increases, the cost savings associated with this change in the new technology outweighs the cost of technical success or failure. Since the United States is attempting to minimize their expected cost per container, the optimal choice is to invest in the new detector. Our intelligent adversary risk analysis model can simultaneously determine the best decision for the United States, who is trying to minimize the expected cost, and the terrorist, who is trying to maximize the expected cost to the United States. Simultaneously modeling the decisions of the defender and attacker provides a more accurate picture of reality and could provide important insights to the real situation that may have been missed with other techniques. The model is extremely sensitive to certain inputs and parameters, even though the values are in line with what is available in the literature, it is important to understand the sensitivities. Two inputs that were found to be particularly important are the expected cost for physically inspecting a cargo container, and the cost of implementing the technology needed for the new screening device. Using this model the decision maker can construct more accurate judgments based on the true situation. This increase in accuracy could save lives with the decisions being made. The model can also help the decision maker understand the interdependencies of the model and visually see how his resource allocations affect the optimal decisions of the defender and the attacker.
52

INCORPORATING PUBLIC PERCEPTIONS INTO THE SELECTION OF A NUCLEAR FUEL CYCLE

Swanson, John M 01 January 2015 (has links)
The final disposal location for used nuclear fuel in the U.S. remains unresolved. A major complication in resolving this issue has historically been the lack of public acceptance. This motivates the creation of a decision making model for selecting a nuclear fuel cycle in the U.S. that incorporates the preferences of the public. A model based on the Analytic Hierarchy Process (AHP) was created, tested, and shown to be problematic in incorporating public opinion into decision objectives. A new model based on Multi-Attribute Utility Theory (MAUT) has been created. This model contains the fundamental objectives for both technical and non-technical factors in both the short and long term for the decision. Additionally, the relevant subject matter experts involved in a nuclear fuel cycle selection are evaluated based on the public's perception of their qualifications, and environmental scientists are found to be considered equally as qualified as nuclear engineers and scientists.
53

Developing a Multi-Objective Decision Model for Maximizing IS Security within an Organization

May, Jeffrey Lee 01 January 2008 (has links)
Numerous IS researchers have argued that IS Security can be more effectively managed if the emphasis goes beyond the technical means of protecting information resources. In an effort to adopt a broader perspective that accounts for issues that transcend technical means alone, Dhillon and Torkzadeh (2006) present an array of 9 fundamental and 16 means objectives that are essential for maximizing IS security in an organization. These objectives were derived using a value-focused thinking approach and are organized into a conceptual framework. This conceptual framework provides a rigorous theoretical base for considering IS security in a manner that accounts for both technical and organizational issues; however, no direction is provided for using these objectives so that informed decisions can be made. As a result, the goal of this dissertation is to develop a decision model using Multiple Objective Decision Analysis (MODA) techniques that seek to provide informed alternatives to decision makers who desire to maximize IS security within an organization.
54

[en] MINING PROJECT VALUATION APPLYING THE REAL OPTION THEORY / [pt] AVALIAÇÃO DE PROJETO DE MINERAÇÃO APLICANDO A TEORIA DE OPÇÕES REAIS

ALEXANDRE PANZA VIDAL 27 January 2009 (has links)
[pt] A demanda por commodities mineral e energético no mundo vem sofrendo um forte aumento nos últimos anos causado principalmente pelo crescimento da economia chinesa. No setor de minério de ferro movimentos de aquisições e consolidações são cada vez mais freqüentes pois grandes grupos siderúrgicos buscam, por meio de aquisições, garantir o fornecimento de seu principal insumo e se proteger contra a forte variação do preço no mercado e, por outro lado, empresas de mineração, ao se consolidarem, se protegem contra essas ameaças. A avaliação de novos projetos de mineração é fundamental para identificar o valor da empresa ao considerarmos que uma empresa de mineração é um portfólio de projetos. Dada as características de alguns projetos de mineração, o uso da Teoria de Opções Reais permite uma avaliação mais eficiente do valor destes projetos em função das flexibilidades gerenciais e incertezas de mercado. Esta dissertação procura rever e aplicar os conceitos de opções reais utilizando a probabilidade neutra ao risco e processo estocástico com drifts de crescimento da variável de incerteza através de um projeto de mineração hipotético com a opção de expandir sua capacidade em um prazo de 5 anos. / [en] The world demand for mineral and energetic commodities is rising strongly in the last years due mainly to the growth of the Chinese economy. In the iron ore industry movements of merger and acquisition are more frequent therefore steel producers groups are looking to, by means of acquisition, guarantee their iron ore supply and to protect against the huge volatility of price in the market. On the other hand mining companies are protecting their business against these threats by merger operations. In this context, the valuation of new mining projects is essential to identify the enterprise value, considering that a mining company is a portfolio of projects. Given the characteristics of some mining projects, the use of the Real Option Theory allows a more efficiently valuation be done in presence of flexibilities and market uncertainties. This thesis intent to apply the concepts of real option, considering the risk neutral probability and stochastic process with growth drift of the variable of uncertainty, thru a hypothetic mining project, which holds a capacity expansion option that can be exercised in the five year time.
55

[en] RISK MANAGEMENT IN PROGRAMS: A STRUCTURED APPROACH WITH FOCUS ON THE ANALYSIS AND TREATMENT OF RISKS / [pt] GERENCIAMENTO DE RISCOS EM PROGRAMAS: UMA ABORDAGEM ESTRUTURADA COM FOCO NA ANÁLISE E TRATAMENTO DO RISCO

BRUNO RAFAEL DIAS DE LUCENA 05 March 2013 (has links)
[pt] Esta tese tem por objetivo estabelecer bases teóricas e propor um método para estruturar o gerenciamento de riscos em programas. Sua motivação é o número crescente de organizações que, por meio de programas, buscam descentralizar ações gerenciais e aumentar a eficácia de projetos concentrando o foco em seus objetivos estratégicos. A despeito de sua importância, a literatura não apresenta orientações bem fundamentadas para a prática do gerenciamento de riscos em programas. Tal carência parece ter origem em conceitos mal formados sobre vários aspectos. A pesquisa procurou preencher tais lacunas conceituais por meio de uma revisão bibliográfica crítica e de um levantamento feito junto a profissionais familiarizados com a gerência de programas. Uma classificação de riscos e diagramas de influência são os elementos básicos do método proposto para estruturar o gerenciamento de riscos. O levantamento indicou que alguns aspectos mais críticos do método proposto são bem aceitos pelos profissionais especializados. / [en] This dissertation seeks to establish a theoretical basis, and a method, for structuring risk management programs. It was motivated by the increasing number of organizations that resort to programs as means to decentralize managerial actions and increase the effectiveness of projects focusing on their strategic objectives. Despite its importance, the literature does not provide well-grounded guidelines for the practice of program risk-management. Such deficiency appears to stem from malformed concepts on various aspects of program management. The research sought to fill such conceptual gaps through a critical literature review and a survey with professionals familiar with program management. A risk classification and influence diagrams are the basic elements of the method proposed for structuring risk management. The survey indicated that some of the most critical aspects of the proposed method are well accepted by professionals.
56

[en] A DISCRETE TIME APPLICATION OF REAL OPTIONS THEORY FOR THE VALUATION OF A HIGHWAY CONCESSION PROJECT IN BRAZIL / [pt] UMA APLICAÇÃO DA TEORIA DAS OPÇÕES REAIS EM TEMPO DISCRETO PARA AVALIAÇÃO DE UMA CONCESSÃO RODOVIÁRIA NO BRASIL

LUIZ EDUARDO TEIXEIRA BRANDAO 01 July 2004 (has links)
[pt] Um dos problemas da avaliação por Opções Reais é a exigência de se ter mercados completos para que possam ser utilizados métodos baseados no princípio da não arbitragem para a sua solução. Outro problema é a inclusão de duas ou mais fontes de incerteza na modelagem matemática do projeto, que aumenta a complexidade do problema, especialmente quando essas incertezas envolvem risco privado, não correlacionado com o mercado. Este trabalho sintetiza conceitos aplicados a Teoria das Opções Reais desenvolvidos por diversos autores com ferramentas de Decision Analysis para propor uma metodologia de avaliação de projetos em tempo discreto utilizando algoritmo próprio aplicado a modelo de árvore de decisão com malha binomial que pode ser implementada utilizando-se programas de software padrão já existentes no mercado. O método é computacionalmente intenso, mas de modelagem mais simples e intuitiva que os métodos tradicionais de Opções Reais, permitindo assim uma maior flexibilidade na elaboração do modelo. Esta metodologia é aplicada ao problema de valoração de uma concessão rodoviária no Brasil com flexibilidade gerencial em mercados incompletos e risco político. / [en] One of the problems of the evaluation for Real Options is the need to have complete markets so that non arbitrage methods can be used for its solution. When that is not the case, or when the determination of a dynamic portfolio of market securities that replicate the stochastic characteristics of the project is not feasible for any reason, the alternative is to use an exogenous and arbitrary discount rate. Another problem is the inclusion of two or more uncertainty sources in the mathematical modeling of the project, which brings a certain degree of complexity to the problem, especially when those uncertainties involve private risk, not correlated with the market. This work synthesizes some Real Options Theory concepts developed by several authors with Decision Analysis tools to propose a method for evaluation of projects in incomplete markets by dynamic programming using an innovative algorithm to model the project`s stochastic process with a binomial lattice and decision tree. The method is computationally intense, but simpler and more intuitive than that the traditional methods of Real Options, allowing for a greater flexibility in the modeling of the problem. This methodology is applied to the problem of the valuation a highway concession in Brazil with managerial flexibility in incomplete markets and political risk.
57

Métodos de análise de decisão multicritério para a seleção de recursos em ambientes loT / Multicriteria decision analysis techniques for resources selection in IoT environments

Nunes, Luiz Henrique 12 December 2018 (has links)
A Internet das coisas é constituída de objetos que possuem pequenos sensores e atuadores capazes de interagir com o ambiente. Tais objetos ou coisas estão interconectados entre si e com acesso à Internet por meio de redes com e sem fio. A combinação entre os dispositivos embarcados com sensores e o acesso à Internet possibilita a comunicação dos recursos do mundo físico com o espaço cibernético, desempenhando um papel fundamental na resolução de muitos desafios encontrados na sociedade atual. Porém, a maioria das aplicações existentes são dedicadas a resolver problemas específicos utilizando tais recursos apenas em redes internas, limitando a real capacidade da Internet das Coisas. Diversos trabalhos na literatura propõem a reutilização de tais recursos em forma de serviço por meio de modelos como Dados como Serviço e Sensoriamento como Serviço. Neste contexto, em que potencialmente milhares de recursos podem transferir dados semelhantes de aplicações diferentes, a utilização de técnicas que possam selecionar recursos de forma sensível a contexto torna-se imprescindível. Nesta tese são propostos um conjunto de métodos para melhorar a relação custo-benefício na seleção de recursos em ambientes IoT, auxiliando na tomada de decisão durante a seleção dos recursos que serão ofertados como serviço. Os resultados obtidos por meio de estudos de caso, permitiram a comparação da qualidade da solução e do custo computacional das técnicas aplicadas na seleção de recursos em ambientes IoT, bem como o desenvolvimento de duas novas técnicas para a seleção de recursos, denominadas Elimination Sort e Fast Elimination Sort. / The Internet of Things is composed of objects which have small sensors and actuators capable of interacting with the environment. Such objects or things are interconnected with each other and has access to the Internet through wired and wireless networks. The combination of embedded devices with sensors and access to the Internet become it possible to communicate the resources of the physical world with the cyberspace, playing a key role in solving many challenges found in todays society. However, most existing applications solves a specific problem using its resources just for own purpose, limiting the actual ability of the Internet of Things. Several works propose the reuse of such resources through service models such as Data as Service and Sensing as a Service. In this context, where thousands of resources can transfer similar data from different applications, the use of techniques that can select these features in a context-sensitive way becomes essential. In this thesis, a set of methods to improve the cost-benefit of the process of selection of resources in IoT environments is proposed to support the decision making during resource selection that will be offered as a service. The results obtained through a case study allowed the comparison of the solution quality and the computational cost of the techniques applied for resource selection in IoT environments, as well as the development of two new techniques for the selection of resources called Elimination Sort and Fast Elimination Sort.
58

Gerenciamento de incertezas por análise de decisões: aplicações à otimização da produção e demandas incertas / Uncertainty management through decision analysis: applications to production optimization and uncertain demands

Danilo Augusto Sarti 05 December 2013 (has links)
A produção de sementes de milho é um processo que engloba variáveis de diversas naturezas. A quantidade de sementes a ser produzida é decisão fundamental para um produtor de sementes. Dessa forma, é necessário contextualizar a decisão da quantidade a se produzir dentro de todas as decisões que um produtor de sementes realiza no desenvolvimento de produtos e na produção. Assim, é possível com o uso de um modelo de custo associado ao excesso de oferta e demanda, determinar-se a quantidade de sementes à ser produzida que otimize este custo. Para tal, é necessário a obtenção de uma projeção para a demanda futura por simulação computacional. Dentro desse contexto, foi confeccionado um fluxograma para o processo de desenvolvimento de produtos e produção de sementes. Após isso, mapearam-se as decisões envolvidas com uso de diagramas de influências e determinou-se através de projeção da demanda por simulação a quantidade ótima de sementes de um cultivar a ser produzida para abastecer uma região de referência, determinada pelo modelo econômico desenvolvido no referencial. Além disso, devido à quantidade de informações simuladas foi possível a obtenção das probabilidades de diferentes faixas de lucro obtidas com o cultivar de interesse na região considerada. / Corn seed production is a complex process. The quantity of seed that a firm should produce is an important parameter. It is important for a seed producer to put the decision related to quantity to be produced in the context of all decisions made for product development and for the production process. Thus, with support of an model for costs related to excess of demand or supply, a firm could set the optimal quantity of seed to be produced that minimizes this cost. This methodology requires the use of a projection of demand through simulation. In these context, was built a flowchart for the process of product development and seed production. Then decisions and related uncertainties in these processes were mapped through influence diagrams. After the map production, the decision regarding the quantity to be produced was put in context and this quantity was determined by the methodology discussed. The analysis considered a cultivar and an interest region. Information got through simulation was also used to quantify the probabilities of different potential profits reached by the cultivar in the interest region.
59

Gerenciamento de incertezas por análise de decisões: aplicações à otimização da produção e demandas incertas / Uncertainty management through decision analysis: applications to production optimization and uncertain demands

Sarti, Danilo Augusto 05 December 2013 (has links)
A produção de sementes de milho é um processo que engloba variáveis de diversas naturezas. A quantidade de sementes a ser produzida é decisão fundamental para um produtor de sementes. Dessa forma, é necessário contextualizar a decisão da quantidade a se produzir dentro de todas as decisões que um produtor de sementes realiza no desenvolvimento de produtos e na produção. Assim, é possível com o uso de um modelo de custo associado ao excesso de oferta e demanda, determinar-se a quantidade de sementes à ser produzida que otimize este custo. Para tal, é necessário a obtenção de uma projeção para a demanda futura por simulação computacional. Dentro desse contexto, foi confeccionado um fluxograma para o processo de desenvolvimento de produtos e produção de sementes. Após isso, mapearam-se as decisões envolvidas com uso de diagramas de influências e determinou-se através de projeção da demanda por simulação a quantidade ótima de sementes de um cultivar a ser produzida para abastecer uma região de referência, determinada pelo modelo econômico desenvolvido no referencial. Além disso, devido à quantidade de informações simuladas foi possível a obtenção das probabilidades de diferentes faixas de lucro obtidas com o cultivar de interesse na região considerada. / Corn seed production is a complex process. The quantity of seed that a firm should produce is an important parameter. It is important for a seed producer to put the decision related to quantity to be produced in the context of all decisions made for product development and for the production process. Thus, with support of an model for costs related to excess of demand or supply, a firm could set the optimal quantity of seed to be produced that minimizes this cost. This methodology requires the use of a projection of demand through simulation. In these context, was built a flowchart for the process of product development and seed production. Then decisions and related uncertainties in these processes were mapped through influence diagrams. After the map production, the decision regarding the quantity to be produced was put in context and this quantity was determined by the methodology discussed. The analysis considered a cultivar and an interest region. Information got through simulation was also used to quantify the probabilities of different potential profits reached by the cultivar in the interest region.
60

A Systemic Approach Framework for Operational Risk : – SAFOR –

Kessler, Anna-Maria January 2007 (has links)
<p>This thesis attempts to describe the essential systems features of a complex real-world domain of operational risk (OR) in banking, by employing general systems theory (GST) as the guiding method. An implementational framework (SAFOR) is presented for operational risk management (ORM), the target of which is to manage and mitigate the risk-around-loss causes. Since reasoning about OR is often scenario based, the framework also includes methods for decision making in addition to Value at Risk (VaR) and Conditional Value at Risk (CVaR). Other computational models that yield prediction intervals are discussed as well. Because the banking industry is one of the most mature sectors when it comes to OR, and contains the most data points, the discussion in this thesis evolves around such institutions. The present state-of-the-art in OR management for banking is surveyed using a systemic-holistic approach and the model framework is presented against this discussion. Tools and concepts from systems theory and systems thinking are employed for assessing systems properties and gaining insights into the interaction of various components. This brings about a number of advantages. This is not in disagreement with current suggestions such as those of the Basle Committee (Basel II), which is doing an excellent job in proving the state-of-the-art in best practice for banking institutions. Rather, this thesis offers a complementary perspective, looking at essentially the same problems but in a broader context and with a differing view.</p><p>OR data has been hard to come by in banking. Confidentiality and difficulties in quantifying OR as well as the short time data has been gathered in a consistent way are some of the reasons for this. Therefore, no case study has been done. Instead, we have chosen to look into a published bank application of an advanced OR model. The application shows that the technique holds as validation of the SAFOR modules.</p>

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