Background: Respiratory illnesses can have a substantial impact on population health and burden hospitals in terms of patient load. Advance warnings of the spread of such illness could inform public health interventions and help hospitals manage patient services. Previous research showed that calls for respiratory complaints to Telehealth Ontario are correlated up to two weeks in advance with emergency department visits for respiratory illness at the provincial level. Objectives: This thesis examined whether Telehealth Ontario calls for respiratory complaints could be used to accurately forecast the daily and weekly number of emergency department visits for respiratory illness at the health unit level for each of the 36 health units in Ontario up to 14 days in advance in the context of a real-time syndromic surveillance system. The forecasting abilities of three different time series modeling techniques were compared. Methods: The thesis used hospital emergency department visit data from the National Ambulatory Care Reporting System database and Telehealth Ontario call data and from June 1, 2004 to March 31, 2006. Parallel Cascade Identification (PCI), Fast Orthogonal Search (FOS), and Numerical Methods for Subspace State Space System Identification (N4SID) algorithms were used to create prediction models for the daily number of emergency department visits using Telehealth call counts and holiday/weekends as predictors. Prediction models were constructed using the first year of the study data and their accuracy was measured over the second year of data. Factors associated with prediction accuracy were examined. Results: Forecast error varied widely across health units. Prediction error increased with lead time and lower call-to-visits ratio. Compared with N4SID, PCI and FOS had significantly lower forecast error. Forecasts of the weekly aggregate number of visits showed little evidence of ability to accurately flag corresponding actual increases. However, when visits were aggregated over a four day period, increases could be flagged more accurately than chance in six of the 36 health units accounting for approximately half of the Ontario population. Conclusions: This thesis suggests that Telehealth Ontario data collected by a real-time syndromic surveillance system could play a role in forecasting health services demand for respiratory illness. / Thesis (Master, Community Health & Epidemiology) -- Queen's University, 2009-08-11 16:20:44.553

In this study we look at the problem of analysing survival data in the presence of longitudinally collected covariates. New methodology for analysing such data has been developed through the use of hidden Markov modeling. Special attention has been given to the case of large information volume, where a preliminary data reduction is necessary. Novel graphical diagnostics have been proposed to assess goodness of fit and significance of covariates. The methodology developed has been applied to the data collected on behaviors of Mexican fruit flies, which were monitored throughout their lives. It has been found that certain patterns in eating behavior may serve as an aging marker. In particular it has been established that the frequency of eating is positively correlated with survival times. / Thesis (Ph.D, Mathematics & Statistics) -- Queen's University, 2010-04-26 18:34:01.131

Evidence for a human contribution to climatic changes during the past century is accumulating rapidly. Given the strength of the evidence, it seems natural to ask whether forcing projections can be used to forecast climate change. A Bayesian method for post-processing forced climate model simulations that produces probabilistic hindcasts of inter-decadal temperature changes on large spatial scales is proposed. Hindcasts produced for the last two decades of the 20th century are shown to be skillful. The suggestion that skillful decadal forecasts can be produced on large regional scales by exploiting the response to anthropogenic forcing provides additional evidence that anthropogenic change in the composition of the atmosphere has influenced our climate. In the absence of large negative volcanic forcing on the climate system (which cannot presently be forecast), the global mean temperature for the decade 2000-2009 is predicted to lie above the 1970-1999 normal with probability 0.94. The global mean temperature anomaly for this decade relative to 1970-1999 is predicted to be 0.35C (5-95% confidence range: 0.21C-0.48C). Reconstruction of temperature variability of the past centuries using climate proxy data can also provide important information on the role of anthropogenic forcing in the observed 20th century warming. A state-space model approach that allows incorporation of additional non-temperature information, such as the estimated response to external forcing, to reconstruct historical temperature is proposed. An advantage of this approach is that it permits simultaneous reconstruction and detection analysis as well as future projection. A difficulty in using this approach is that estimation of several unknown state-space model parameters is required. To take advantage of the data structure in the reconstruction problem, the existing parameter estimation approach is modified, resulting in two new estimation approaches. The competing estimation approaches are compared based on theoretical grounds and through simulation studies. The two new estimation approaches generally perform better than the existing approach. A number of studies have attempted to reconstruct hemispheric mean temperature for the past millennium from proxy climate indicators. Different statistical methods are used in these studies and it therefore seems natural to ask which method is more reliable. An empirical comparison between the different reconstruction methods is considered using both climate model data and real-world paleoclimate proxy data. The proposed state-space model approach and the RegEM method generally perform better than their competitors when reconstructing interannual variations in Northern Hemispheric mean surface air temperature. On the other hand, a variety of methods are seen to perform well when reconstructing decadal temperature variability. The similarity in performance provides evidence that the difference between many real-world reconstructions is more likely to be due to the choice of the proxy series, or the use of difference target seasons or latitudes, than to the choice of statistical method.

Recently, the environmental impact of aircraft and rising fuel prices have become an increasing concern in the aviation industry. To address these problems, organizations such as NASA have set demanding goals for reducing aircraft emissions, fuel burn, and noise. In an effort to reach the goals, a movement toward more-electric aircraft and electric propulsion has emerged. With this movement, the number of critical electrical loads on an aircraft is increasing causing power system reliability to be a point of concern. Currently, power system reliability is maintained through the use of back-up power supplies such as batteries and ram-air-turbines (RATs). However, the increasing power requirements for critical loads will quickly outgrow the capacity of the emergency devices. Therefore, reliability needs to be addressed when designing the primary power distribution system. Power system reliability is a function of component reliability and redundancy. Component reliability is often not determined until detailed component design has occurred; however, the amount of redundancy in the system is often set during the system architecting phase. In order to meet the capacity and reliability requirements of future power distribution systems, a method for redundancy allocation during the system architecting phase is needed. This thesis presents an aircraft power system design methodology that is based upon the engineering decision process. The methodology provides a redundancy allocation strategy and quantitative trade-off environment to compare architecture and technology combinations based upon system capacity, weight, and reliability criteria. The methodology is demonstrated by architecting the power distribution system of an aircraft using turboelectric propulsion. The first step in the process is determining the design criteria which includes a 40 MW capacity requirement, a 20 MW capacity requirement for the an engine-out scenario, and a maximum catastrophic failure rate of one failure per billion flight hours. The next step is determining gaps between the performance of current power distribution systems and the requirements of the turboelectric system. A baseline architecture is analyzed by sizing the system using the turboelectric system power requirements and by calculating reliability using a stochastic flow network. To overcome the deficiencies discovered, new technologies and architectures are considered. Global optimization methods are used to find technology and architecture combinations that meet the system objectives and requirements. Lastly, a dynamic modeling environment is constructed to study the performance and stability of the candidate architectures. The combination of the optimization process and dynamic modeling facilitates the selection of a power system architecture that meets the system requirements and objectives.

在台灣，遠期外匯可分為有本金遠期外匯(DF)及無本金遠期外匯(NDF)，其中無本金遠期外匯為銀行與客戶訂定之無標準化規格契約， 其特色是在契約到期時，交易雙方僅就約定之匯率差額進行交割，不須交割本金。此特色也使得避險或是投機時較為節省資金成本， 故NDF在台灣遠期外匯市場的交易量有逐漸增加的趨勢。 然而在理性預期下，不論是DF或是NDF都應該是即期匯率的最佳預測值，即所謂的市場效率性。傳統統計方法通常用線性迴歸來檢定市場效率性， 但卻常推估出互相衝突的結論。本文利用Kalman approach推估遠期外匯之貼水，希望藉此觀察出不同時間點，台灣遠期外匯市場的效率性。 研究結果發現台灣遠期外匯之貼水在金融風暴之後呈現穩定，表示此時間內台灣外匯市場具有效率性。 另外，在金融風暴之後NDF貼水之波動較DF而且為大，表示程度上NDF較不具效率性，可能跟NDF之投機性交易較多有關係。 雖然如此，NDF市場之投機交易，並沒有使NDF之貼水波動達到無效率的地步，故建議央行可逐步放寬對NDF交易之限制， 以促進市場交易之健全。 / The forward exchange are divided into deliverable forward(DF) and non-deliverable forward(NDF) exchange in Taiwan . NDFs are foreign exchange derivative products traded over the counter. The parties of the NDF contract settle the transaction, not by delivering the underlying pair of currencies, but by making a net payment in a convertible currency proportional to the difference between the agreed forward exchange rate and the subsequently realised spot fixing. Under the rational expectation of foreign traders, not only DF exchange rate but also NDF will be the best predictor of the spot exchange. Tradional statistics methods use linear regressions to test whether the markets are efficiency or not. However, this study consider a Kalman approach to estimate the model and predict the spot exchange rate. The results can be found by observing the estimated premia: first, the premia show a certain degree of persistence after the Asian crisis. Second, the premium of NDF rate is more fluctuated than DF rates after the Asian crisis. It may present that the Non-deliverable forward exchange market in Taiwan has many speculative transactions. However, considering the process what we analyze the difference between the future spot rates and forward rates, it seems that the forward exchange markets in Taiwan have efficiency because of their persistence over time. Since the speculative transactions have no enough power to make the NDF markets inefficient, the Central Bank of Taiwan may suggest cancel the restrictions of NDF transactions.

The objective of this research is to demonstrate how an underlying system's state vector distribution can be determined in a distributed heterogeneous sensor network with reduced subspace observability at the individual nodes. We show how the network, as a whole, is capable of observing the target state vector even if the individual nodes are not capable of observing it locally. The initialization algorithm presented in this work can generate the initial state vector distribution for networks with a variety of sensor types as long as the measurements at the individual nodes are known functions of the target state vector. Initialization is accomplished through a novel distributed implementation of the particle filter that involves serial particle proposal and weighting strategies, which can be accomplished without sharing raw data between individual nodes in the network. The algorithm is capable of handling missed detections and clutter as well as compensating for delays introduced by processing, communication and finite signal propagation velocities. If multiple events of interest occur, their individual states can be initialized simultaneously without requiring explicit data association across nodes. The resulting distributions can be used to initialize a variety of distributed joint tracking algorithms. In such applications, the initialization algorithm can initialize additional target tracks as targets come and go during the operation of the system with multiple targets under track.

In Artificial Intelligence, especially in area of constraint programming, it's popular to design various modeling languages which allow solving problems on domain level and by using domain specific abstractions. Techniques known from research on Domain-Specific Languages are often useful in this effort. Functional programming languages offer new tools for designing such languages, particularly Domain-Specific Embedded Languages. This work investigates the advantages and disadvantages of using functional programming for designing and implementing a Domain-Specific Embedded Language for state space search problems.

Existem vários problemas clássicos na área de pesquisa operacional que trabalham com o tema vinculado à designação de veículos em um sistema logístico, entre eles o Problema de Escalonamento de Veículos com Múltiplas Garagens (MDVSP). Esses modelos são largamente utilizados e representam uma das etapas essenciais para o planejamento de trânsito em massa (HAGHANI e BANIHASHEMI, 2002). Tratando-se de sistemas logísticos reais, dificilmente encontra-se um ambiente onde os veículos devem partir e chegar a uma única garagem, por isso torna-se necessário o planejamento das seqüências de viagens de modo a reduzir os custos de deslocamentos com o aproveitamento das múltiplas garagens distribuídas geograficamente. Infelizmente, considerando a complexidade exponencial do MDVSP, muitas vezes sua aplicação torna-se inviável na solução de problemas reais. Por essa razão, poucos trabalhos abordam o MDVSP de modo a conseguir solucionar o problema para uma grande quantidade de viagens e garagens. A maioria das pesquisas trabalha com instâncias inferiores a 500 viagens e quatro garagens, mostrando-se pouco aplicáveis. Esse estudo refere-se a um trabalho de pesquisa operacional que aborda soluções de problemas de escalonamento de veículos com múltiplas garagens (MDVSP) considerando sua aplicabilidade em sistemas reais. Tendo em vista a complexidade exponencial do MDVSP, nesse estudo optou-se por tratar o problema através de uma abordagem baseada na redução do espaço de estados e na utilização de heurísticas. Durante essa pesquisa três procedimentos de redução do espaço de estados foram adotados. Os resultados apontam que é possível reduzir em até 98% o número de variáveis nesses problemas sem comprometer uma solução satisfatória ou ótima. Além dos procedimentos de redução do espaço de estados, foi desenvolvido um procedimento de buscar a solução do MDVSP. Através desse último procedimento foi possível resolver o MDVSP com até 3000 viagens e oito garagens. Sendo assim, nesse estudo desenvolveram-se modelos que servem para o planejamento de um sistema logístico através da aplicação de cenários, com vistas a permitir a geração e análise de alternativas de escalonamento. Objetivou-se com isso, fornecer ao sistema logístico um modelo amplo que permita a escolha da ação mais conveniente e eficiente a ser tomada em modelos compostos por diversas garagens. / There are many classics problems in operations research concerning optimal assignment vehicles in logistical system. The multiple depot vehicle scheduling problem (MDVSP) is one of them. This problem is largely used to represent and solve mass transit planning (HAGHANI e BANIHASHEMI, 2002). Considering a real logistical system, it is very difficult to find out a situation where the vehicles must leave and come to only one depot. In general, the shipping company has several depots located at different sites in a network. In this way, it is strongly necessary to reduce cost through the planning of sequence trips taking into account multiple depots geographically distributed. Unfortunately, the exponential complexity of the MDVSP reduces, in the most cases, the applicability of this problem in the real world. For this reason, few researchers address the MDVSP to solve real world problems considering a large number of trips and depots. The majority of the research dealing with the MDVSP works with instances lower than 500 trips and four depots, what can be considered a major constraint for its practical use. The main objective of this work is to solve the MDVSP for very large instances. A state space reduction approach combined with heuristic procedures are developed to obtain a realistic way of solving this complex problem. In this research, three state space reduction procedures were developed. The results appointed that is possible to reduce until 98% of variables in the MDVSP without jeopardizing an optimal solution. Furthermore, heuristic procedures were developed to obtain solutions without relaxing any realworld constraint of the problem. The solution procedure developed was compared with wellknown available instances. The method is able to solve the MDVSP with 3000 trips and eight depots in less than 11 minutes. Although the solution process does not obtain the best solution in all tested instances, it is by far the quickest.

O presente estudo analisa a evolução, o comportamento e a natureza cíclica do crédito brasileiro no período compreendido entre janeiro de 2003 e dezembro de 2013. Mais especificamente, verifica se a postura da condução da oferta de crédito público, de fato, destoou daquela apresentada pelo crédito privado, especialmente após o advento da crise financeira de 2007/2008. Para tanto, se vale de uma revisão das literaturas nacional e internacional e realiza um resgate histórico dos principais bancos públicos do Brasil – etapa que se dá concomitantemente à análise da evolução do desempenho dos mesmos nos últimos tempos. Com isso, além de se mostrar a performance recente destas instituições, demonstra-se também que, a despeito da redução da participação das instituições bancárias públicas na década de 1990, estas foram decisivas para a melhor reação da economia brasileira frente aos efeitos adversos da crise de 2007/2008 – o que fornece mais indícios da validade do problema de pesquisa e traz, por conseguinte, mais força à hipótese de trabalho. Na sequência, são discutidos alguns aspectos metodológicos no intuito de identificar qual a modelagem econométrica seria a mais adequada para descobrir como os bancos públicos e privados se comportaram no período abordado e, mais especificamente, como eles reagiram após o advento da crise financeira dos subprimes – procurou-se também, uma abordagem que, especificamente, ajudasse a desvendar a natureza cíclica dos créditos privado e público. Nesse sentido, optou-se pela modelagem econométrica denominada de Modelos Estruturais de Espaço de Estados, também conhecida como Modelos de Componentes não-observáveis. Através desta metodologia, foi possível verificar, de maneira endógena, se existiram e quando ocorreram outliers e quebras estruturais nas séries de dados referentes à evolução do crédito brasileiro no período. Os resultados obtidos vieram a corroborar a hipótese de trabalho, mostrando a existência de uma relação negativa e estatisticamente significante entre as variáveis representativas do produto interno bruto e as do crédito público e do crédito total. Dessa maneira, chegou-se à conclusão de que, realmente, o crédito público mostrou características contra-cíclicas no período de 2003 a 2013, especialmente após o ano de 2008 – fato que é reforçado pela ocorrência de quebras de nível positivas neste ano. / This study analyses the evolution, behavior and cyclical nature of the Brazilian credit supply in the period from January 2003 to December 2013. Specifically, it checks if the posture of public credit supply’s conduction has differed, indeed, from the one presented by the private credit, particularly after the financial crisis of 2007-08. For this purpose, this paper reviews national and international literature and performs a historical examination of the main Brazilian state-owned banks – which is presented concomitantly to the analysis of their lately performance’s evolution. Therewith, besides showing these institutions’ recent performance, it also demonstrates that, in spite of the reduction in the state-owned banks participation in the 1990s, these were decisive to the better reaction of the Brazilian economy in the face of the adverse effects of the 2007-08 crisis – which provides further evidence of the research question validity and brings, therefore, strenght to the working hypothesis. In the next step, some methodological aspects are discussed aiming to identify which would be the most appropriate econometric modelling to find out how the public and private banks behaved in this period, and specifically, to discover how they reacted after the subprime financial crisis – in this point, a research was made in order to identify an approach that, particularly, helped to reveal the cyclical nature of private and public credits. It was decided to use an econometric approach called Space-State Modelling, also known as Unobservable Component Models. Through this methodology, it was possible to check, in an endogenous way, if there were – and when they occurred – outliers and structural breaks in the data series referring to the Brazilian credit evolution in the period. The results came to support the working hypothesis, showing the existence of a negative and statistically significant relationship between the variables representing the gross domestic product and the ones representing public credit and the total credit. Thus, it was concluded that the public credit, indeed, showed counter-cyclical characteristics in the period between 2003 and 2013, especially after 2008 – a fact that is reinforced by the occurrence of positive level breaks in this year.

Considerando a importância de uma medida de alta frequência para o PIB do Rio Grande do Sul, o principal indicador de atividade econômica do estado, este trabalho foi dividido em três objetivos. O primeiro foi a estimação de uma série com frequência mensal para o PIB real do Rio Grande do Sul entre janeiro de 2002 e março de 2017, dado que o mesmo só é contabilizado em frequência trimestral. Para tanto, foi utilizado um modelo em espaço de estados que permite a estimação e nowcast do PIB mensal, utilizando séries coincidentes como fonte de informação para a interpolação dos dados trimestrais do PIB, em linha com Bernanke, Gertler e Watson (1997), Mönch e Uhlig (2005) e Issler e Notini (2016). O segundo objetivo foi comparar a série estimada com um indicador de atividade calculado pelo Banco Central do Brasil para o estado, o Índice de Atividade Econômica Regional (IBCR-RS), tanto em termos metodológicos como na capacidade em antecipar as variações do PIB trimestral antes de sua divulgação (nowcasting). O terceiro objetivo foi estabelecer a cronologia dos ciclos de expansão e recessão da economia gaúcha com o uso do algoritmo de Bry e Boschan (1971). Após a etapa de seleção das séries coincidentes e da estimação de diversos modelos de interpolação, foi escolhido para gerar a série mensal do PIB o modelo que utiliza somente a produção industrial como variável auxiliar, tendo este apresentado o melhor ajuste. A comparação do PIB mensal interpolado com o IBCR-RS mostrou que, além da vantagem computacional a favor do método proposto neste trabalho, a imposição da disciplina de que as variações do PIB mensal estimado devem ser exatamente iguais às do PIB trimestral faz com que a dinâmica de curto e longo prazo das variáveis sejam idênticas, o que não ocorre com o IBCR-RS. A cronologia dos pontos de inflexão da atividade econômica apontou três períodos recessivos na economia gaúcha desde janeiro de 2002: jun/2003 a abr/2005 (23 meses e queda acumulada de 8,79%); abr/2011 a abr/2012 (13 meses e queda acumulada de 9,47%); e jun/2013 a nov/2016 (42 meses e queda acumulada de 10,41%), sendo o encerramento deste último apontado somente com a inclusão dos resultados estimados pelo modelo para o segundo trimestre de 2017. Finalmente, os resultados do exercício de nowcasting do PIB mostraram desempenho superior do método proposto frente ao IBCR-RS em termos de antecipação do resultado do PIB de um trimestre a frente, tomando como base as medidas de MAE (erro absoluto médio, em inglês) e MSE (erro quadrático médio, em inglês), comumente usadas nesse intuito. / Giving the importance of a high frequency measure for Rio Grande do Sul’s GDP, the main indicator of economic activity of the state, this work was divided into three objectives. The first one was the estimation of monthly frequency series for Rio Grande do Sul’s real GDP between January/2002 and March/2017, since it is only accounted in quarterly basis. Therefore, we used a State-Space model that enables to estimate and nowcast the monthly GDP, using coincident series as a source of information for the interpolation of quarterly GDP data, in line with Bernanke, Gertler e Watson (1997), Mönch e Uhlig (2005) and Issler e Notini (2016). The second objective was to compare the estimated series with an activity indicator calculated by the Central Bank of Brazil for the state, the Regional Economic Activity Index (IBCR-RS), both in methodological terms and in the capability to anticipate the quarterly GDP release (nowcasting). The third objective was to establish the chronology of the cycles of expansion and recession of the economy of Rio Grande do Sul using the algorithm of Bry e Boschan (1971). After the selection of the coincident series and the estimation of several interpolation models, the chosen model to generate the monthly GDP series uses only the industrial production as an auxiliary variable, and this one presented the best fit. The comparison of the monthly GDP interpolated with the IBCR-RS showed that, in addition to the computational advantage in favor of the method proposed in this work, the imposition of the discipline that the estimated monthly GDP changes must be exactly the same as the quarterly GDP makes the short-term and long-term dynamics of the variables are identical, which is not the case with IBCR-RS. The chronology of the turning points of the economic activity pointed to three recessive periods in the economy of Rio Grande do Sul since January 2002: June/2003 to April/2005 (23 months and accumulated drop of 8.79%); April/2011 to April/2012 (13 months and accumulated fall of 9.47%); and June/2013 to November/2016 (42 months and 10.41% accumulated decrease), with the latter one closing only with the inclusion of the results estimated by the model for the second quarter of 2017. Finally, results for GDP’s nowcasting showed superior performance of the proposed method compared to the IBCR-RS in terms of anticipating quarter-to-quarter GDP results, based on the measures of MAE (absolute mean error) and MSE (mean square error), commonly used for this purpose.