As legalized gambling venues continue to emerge throughout the United States, the already present problem of pathological gambling is likely to evolve in to a great issue of social concern. The vast body of literature on the effects of choice and choice overload, or the experience of negative side effects due to large choice arrays, may further contribute to an understanding of gambling behavior and treatment. The current set of experiments sought to extend the previous literature on choice to a gambling context to expand the behavioral model of gambling. The purpose of Experiment I was to determine whether maximizers, or those who tend to carefully examine options, and satisficers, or those who choose with little deliberation, differ in terms of frequency of switching slot machines, a possible behavioral marker of maximization. The results demonstrated that maximizers switched among available slot machines significantly more frequently than satisficers. Experiment II investigated further links between gambling behavior and maximization. A significant correlation between maximization and outcomes of the Problem Gambling Severity Index were observed, suggesting that these phenomena are related. Experiment III tested the effects of an intervention requiring participants to make repeated choices as an abolishing operation on subsequent gambling behavior. Participants who repeatedly made choices gambled significantly fewer trials on slot machines when allowed to play freely compared to those who simply watched a gambling video. Overall, the literature on choice and the phenomena of maximization and choice overload add to the behavioral model of gambling by suggesting new relevant variables in the determination of gambling behavior.

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Chronic iron overload (CIO) in patients leads to a cardiomyopathy characterized by conduction defects, including bradyarrhythmias. Using a murine model of CIO, we explored the effects of iron loading on the electrophyisology of the heart. Telemetric heart rate was reduced in conscious CIO mice compared to controls. Similarly, heart rates were depressed in both isolated CIO hearts and CIO mice following autonomic blockade, suggesting an intrinsic impairment of the SA node (SAN). Indeed, spontaneous action potential frequency was reduced in CIO SAN myocytes. The depressed pacing rate in CIO SAN myocytes was linked to reduced L-type Ca2+ current (ICa,L) density and a rightward shift in ICa,L activation, suggesting a selective reduction in α1D-mediated ICa,L. Western blot analysis demonstrates that the α1D isoform was reduced by ~ 89% in CIO atrial tissue. Therefore, the conduction defects under conditions of CIO are due to reductions in Cav1.3 channel expression in atrial tissue.

Services are computational elements that expose functionality in a platform independent manner. They are the basic building blocks of the service-oriented (SO) design/integration paradigm. Composite Web Services (CWS) aggregate multiple Web Services (WSs), which is typically achieved by use of a workflow language. A workflow coordinates services in a manner that is consistent with the desired overall functionality (e.g. business process).<p> When the atomic and composite services are exposed to various users, the performance and runtime behavior of WSs becomes important. To ensure wide deployment of CWS, the performance issues must be studied. This research focuses on the performance of atomic and composite SOAP (Simple Object Access Protocol) WSs under transient overloads. This research includes conducting experiments with WSs, studying the runtime behavior, and building simulation models of WSs workflow patterns. Simulation models of different WSs workflow patterns are built to study different situations. Timeout and network latency are added to the model to better simulate real systems. The simulation models are used to predict the runtime behavior of WSs and CWS, as well as to improve the performance with existing, limited resources.

Chronic iron overload (CIO) in patients leads to a cardiomyopathy characterized by conduction defects, including bradyarrhythmias. Using a murine model of CIO, we explored the effects of iron loading on the electrophyisology of the heart. Telemetric heart rate was reduced in conscious CIO mice compared to controls. Similarly, heart rates were depressed in both isolated CIO hearts and CIO mice following autonomic blockade, suggesting an intrinsic impairment of the SA node (SAN). Indeed, spontaneous action potential frequency was reduced in CIO SAN myocytes. The depressed pacing rate in CIO SAN myocytes was linked to reduced L-type Ca2+ current (ICa,L) density and a rightward shift in ICa,L activation, suggesting a selective reduction in α1D-mediated ICa,L. Western blot analysis demonstrates that the α1D isoform was reduced by ~ 89% in CIO atrial tissue. Therefore, the conduction defects under conditions of CIO are due to reductions in Cav1.3 channel expression in atrial tissue.

Services are computational elements that expose functionality in a platform independent manner. They are the basic building blocks of the service-oriented (SO) design/integration paradigm. Composite Web Services (CWS) aggregate multiple Web Services (WSs), which is typically achieved by use of a workflow language. A workflow coordinates services in a manner that is consistent with the desired overall functionality (e.g. business process).<p> When the atomic and composite services are exposed to various users, the performance and runtime behavior of WSs becomes important. To ensure wide deployment of CWS, the performance issues must be studied. This research focuses on the performance of atomic and composite SOAP (Simple Object Access Protocol) WSs under transient overloads. This research includes conducting experiments with WSs, studying the runtime behavior, and building simulation models of WSs workflow patterns. Simulation models of different WSs workflow patterns are built to study different situations. Timeout and network latency are added to the model to better simulate real systems. The simulation models are used to predict the runtime behavior of WSs and CWS, as well as to improve the performance with existing, limited resources.

[pt] A operação de um sistema elétrico tem por objetivo atender a carga a todo instante, respeitando as restrições operacionais dos diversos componentes do sistema. Entretanto, devido às flutuações normais da carga ou algum outro distúrbio, o sistema pode vir a operar em estado de emergência. Neste estado, medidas rápidas devem ser tomadas a fim de que uma maior deterioração do sistema seja evitada. Com intuito de auxiliar o operador na tomada de decisões, tem sido desenvolvidos programas que sejam capazes de determinar em tempo real os controles necessários para eliminar as restrições violadas. O corte de carga, apesar de indesejável, às vezes deve ser ordenado com o objetivo de resguardar o sistema pelo menos em parte. O presente trabalho apresenta um método eficiente para resolver problemas de sobrecargas, utilizando o redespacho de geração e corte de carga como opções de controle. As prioridades para utilização destes controles são definidas no método desenvolvido. A solução proposta para o problema mencionado é obtida utilizando o método de Newton. O ponto de operação calculado a cada iteração sofre o desvio mínimo quadrático nas tensões dos barramentos. Entretanto nenhum algoritmo iterativo de otimização é utilizado, mas uma aplicação direta da teoria da inversa generalizada de Moore-Penrose. / [en] An electrical system is designed to supply the load considering the operating constraints of several system components. However, due to normal load fluctuations or disturbances, the system may operate in an emergency state. In this state, fast corrective easures must be taken to avoid cascading events leading to partial or total shut-down. In order to help the operator, advanced softwares have been developed determining, for example, the necessary controls to eliminate violated constraints in real time. The load shedding sometimes must be ordered to maintain at least part of the system. This dissertation describes an efficient method to solve overload problems using generation rescheduling and load shedding as control options. The solution of the mentioned problem is obtained using the Newton’s method and the Moore-Penrose generalized inverse theory. Therefore the evaluation of busbar voltages after each iteration is duly corrected by least square deviations.

[pt] O aumento da complexidade dos sistemas elétricos de potência tem feito crescer o interesse pela operação e controle em tempo real. Tornou-se então necessária, a criação de centros de controle e computadorizados cujo objetivo principal é suprir toda a carga com todas as restrições de operação satisfeitas e a custo mínimo. Evidencia-se assim, a necessidade de desenvolvimento de algoritmos para o controle corretivo da operação em tempo real, como por exemplo para o controle corretivo de sobrecargas. Os algoritmos existentes têm utilizado como modelo as equações não-lineares de potência injetada nodal na forma polar. Estas equações, quando escritas na forma retangular, são quadráticas e apenas os três primeiros termos da expansão em série de Taylor são não-nulos. Desta forma, é possível que o termo da 1ºordem da expansão na forma retangular seja mais representativo das equações não-lineares que o termo da 1ª ordem na forma polar. Isto pode acarretar melhoras na característica de convergência do método de Newton-Raphson. Além disso, é possível utilizar um método de solução de equações quadráticas onde todos os três termos da expansão em série de Taylor são tomados em consideração. Nesta dissertação são desenvolvidos algoritmos de 1ª e 2ª ordens na forma retangular para o controle corretivo de sobrecargas em tempo real. A melhor maneira de se considerar as restrições nas variáveis de controle é mostrada. Os algoritmos utilizam análise de sensibilidade entre as diversas variáveis do sistema e, na busca da melhor formulação, diversos testes com vários sistemas foram efetuados. Os resultados são comparados entre si e com aqueles obtidos com as equações na forma polar. / [en] The increase in complexity of the electrical power systems have risen the interest on real-time operation and control. The built of computarized control centers whose main objective is to supply the loads, with all the operation constratints satisfied at lowest cost, became necessary. Therefore, the development of real-time algorithms for secure and economic operation, as for instance for overload corrective control, turned out to be a consequence. The non-linear injected nodal power equations have been written in polar form in the existing algorithms. In rectangular form in the existing algorithms. In rectangular form, these equations are quadratic and their Taylor series expansion have only the first three terms. Hence, the first order term of the expansion in rectangular form might be more representative of the non-linear equations than the first order term in polar form. This may improve the converge characteristic of the Newton-Raphson method. Moreover, a quadratic equation solution method can be used. In this method, all the three terms of the Taylor series expansion are taken into account. In the dissertation 1st and 2nd orde algorithms in rectangular form for real-time overload corrective control are developed. The best way to deal with constraints on the control variables is pointed out. The algorithms use sensitivity analysis among the many system variables and, searching for the best formulation, the results using several test-systems are compared with each other and with those obtained with the equations in polar form.

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