Este trabalho apresenta um método empírico para previsão de sobrecargas transientes em sistemas computacionais por meio de modelagem dinâmica. A técnica, baseada em aproximações lineares e invariantes no tempo, tem como objetivo identificar a capacidade de um sistema computacional absorver variações na carga de trabalho. Experimentalmente, a identificação dessa capacidade do sistema pode ser feita por meio de técnicas de avaliação de desempenho, em que a abordagem prevalente é a estimação da capacidade estática em regime estacionário de operação, observando-se o desempenho sob demanda constante. Entretanto, essa avaliação não considera o regime transiente do sistema, i.e durante o período de restabelecimento ao regime estacionário após uma perturbação, e durante o qual, o esforço exigido pode ser bastante diverso, e potencialmente acima daquele apurado sob condições de regime estacionário. A proposta deste trabalho é a formulação de uma metodologia para avaliação de desempenho em regime transiente em sistemas computacionais sob carga de trabalho variável e que forneça informação para o dimensionamento de recursos e políticas de controle de admissão que evitem sobrecargas por efeitos transitórios. A metodologia baseia-se na parametrização de um modelo dinâmico a partir de ensaios experimentais, considerando perturbações bruscas e de longa duração, e os resultados são avaliados por comparação das predições do modelo em relação aos objetivos por simulação ou aferição. / This research work introduces an empirical method for the prediction of transient overloads in computer systems by means of dynamical modeling. The technique, based on linear time-invariant approximations, aims at identifying the computer systems capacity in absorbing variations on the workload. Experimentally, this capacity identification can be carried out from performance evaluation methods, whose prevalent approach is the estimation of the static capacity under stationary operational regime, by observing the performance under constant demand. Nevertheless, this kind of evaluation does not take into account the systems transient regime, i.e. the period during of the restablishment to the stationary regime after the perturbation, and within which, the effort required from the systems may be diverse and potentially superior to that measured under the stationary condition. This work proposes the formulation of a methodology for performance evaluation in transient regime of computer systems submitted to variable workloads, aimed at providing information for dimensioning or resources and design of admission control policies capable of avoiding overloads due to transitory effects. The methodology relies on the parametrization of a dynamical model obtained from experimental procedures, considering abrupt, long-lasting distrubances, and the results are evaluated through comparison of the model prediction with the simulated system.

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Approved for public release, distribution is unlimited / Organizational structure has profound effects on a joint force commander's ability to perform military actions. Organizations and their environment exhibit an interdependent relationship, requiring a commander to evolve his organization to rapidly achieve mission accomplishment. The CNO Strategic Studies Group XIX report of September 2000 has identified the FORCEnet as being the basis for the U.S. Navy's future network-centric organization, and outlines a military environment that includes multitudes of manned and unmanned vehicles, platforms, sensors, weapons and warfighters. These naval elements will operate jointly, leveraging organizational structure to rapidly sense, assess, and respond to the defense of the nation's security interests as directed by the President. The focus of this research is to examine this envisioned future military environment, the military actions required to achieve success in that environment and the organizational structure(s) that will best fit those action requirements. / Lieutenant Commander, United States Navy

A presente dissertação tem por objetivo discutir a importância de uma postura resiliente para a busca do urbanismo sustentável. O termo \"sustentável\" e suas variantes passaram por um desgaste nas últimas décadas, formando uma barreira prejudicial à sua aplicação efetiva. A \"resiliência\", surge, então, como uma forma de revisitar a questão, através de um conceito oriundo da física, que possibilita conceber uma transposição teórica para a arquitetura e o urbanismo, disciplinas nas quais o tema pode colaborar na formulação de novas ferramentas e conceitos aplicáveis ao planejamento e projeto. Almeja-se, através da sua conceituação teórica, contribuir para a elaboração de uma postura resiliente e promover o termo \"resiliência urbana\" em direção ao enfrentamento da crise urbana, ocasionada pelo crescimento vertiginoso da urbanização mundial e da consequente aglomeração populacional nas cidades. Nos países em desenvolvimento, essa abordagem pode ser de grande utilidade, dado que a crise urbana é fortalecida pelo avanço da informalidade e pela formação de novos tecidos urbanos às margens do planejamento. O conceito de resiliência, neste caso, possibilita uma discussão voltada às questões de espontaneidade, improvisos, constantes mudanças e transformações, inerentes à condição urbana, se discutido dentro de uma abordagem de Sistemas Adaptativos Complexos. Para tanto, elaborou-se uma análise reflexiva, a fim de aferir a transferência da teoria para prática, a partir de três projetos urbanos já implantados: as intervenções em torno da Línea K, em Medellín, Colômbia, o sistema teleférico do Complexo do Alemão e o Parque Sitiê, ambos na cidade do Rio de Janeiro. A partir daí, pôde-se constatar que a visão sistêmica adaptativa e complexa da resiliência traz a possibilidade de promover a inter-relação entre sociedade, economia e ambiente na construção do meio urbano e, assim, encorajar uma nova postura frente a difusão de um Urbanismo Sustentável. / The present dissertation aims to discuss the importance of a resilient posture in the search for a sustainable urbanism. The term \"sustainable\" and its variants have gone through a wear and tear through the last few decades, forming a barrier which prejudices its effective application. The \"resilience\" term then appears as a way of revisiting this matter, through a concept derived from physics, that allows a theoretical transposition to architecture and urbanism disciplines in which the subject can cooperate in the formulation of new tools and concepts that can be applied into planning and project design process. Over the theoretical conception, it is intended the contribution on the elaboration of a resilient attitude and therefore promotes the term \"urban resilience\" towards the current urban crisis, caused by the dramatical growth of the world urbanization and the consequent population cluster within cities. In developing countries, the approach can be very useful, given that the urban crisis is strengthened by the rise of informality and the formation of new urban networks at the edge of planning actions. The concept of resilience, in this case, enables a discussion focused on spontaneity issues, improvisations, changes and transformations, inherent to the urban condition, discussed within a Complex Adaptive Systems approach. However to elaborate a reflexive analysis it is necessary to verify the transformation of theory into practice from three urban projects already implemented: Line K\'s urban interventions in Medellín, Colombia, cable car system at Alemão Complex and Sitiê Park, both in Rio de Janeiro, Brazil. In conclusion, an adaptive and complex systemic view of resilience has the potential to promote an interrelationship between society, economy and environment during the construction of an urban environment and therefore encourage a new attitude towards the diffusion of Sustainable Urbanism.

The wind turbine generation system (WTGS) exhibits a nonlinear characteristic and its maximum power point varies with changing atmospheric conditions. In order to operate the WTGS at maximum power output under various wind speeds and to avoid using speed encoder in practical applications, it is necessary to improve the controller system to operate the maximum power points in the WTGS. There are three factors to influence wind generator, the wind speed, power coefficient and the radius of blade. The power coefficient depends on the blade pitch angle and tip speed ratio (TSR). The objective of the dissertation is to develop an intelligent controlled wind energy conversion system (WECS) using AC/DC and DC/AC power converters for grid-connected power application. To achieve a fast and stable response for the real power control, an intelligent controller was proposed, which consists of a fuzzy neural network (FNN), a recurrent fuzzy neural network (RFNN), a wilcoxcon radial basis function network (WRBFN) and a improved Elman neural network (IENN) for MPPT. Furthermore, the parameter of the developed FNN, RFNN, WRBFN and IENN are trained on-line using back-propagation learning algorithm. However, the learning rates in the FNN, RFNN, WRBFN, and IENN are usually selected by trial and error method, which is time-consuming. Therefore, modified particle swarm optimization (MPSO) method is adopted to adjust the learning rates to improve the learning capability of the developed RFNN, WRBFN and IENN. Moreover, presents the estimation of the rotor speed is based on the sliding mode and model reference adaptive system (MRAS) speed observer theory. Furthermore, a sensorless vector-control strategy for an induction generator (IG) operating in a grid-connected variable speed wind energy conversion system can be achieved. On the other hand, a WRBFN based with hill-climb searching (HCS) maximum-power-point-tracking (MPPT) strategy is proposed for permanent magnet synchronous generator (PMSG) with a variable speed wind turbine. Finally, many simulation results are provided to show the effectiveness of the proposed intelligent control wind generation systems.

This thesis addresses several synthesis and optimization issues for embedded control systems. Examples of such systems are automotive and avionics systems in which physical processes are controlled by embedded computers through sensor and actuator interfaces. The execution of multiple control applications, spanning several computation and communication components, leads to a complex temporal behavior that affects control quality. The relationship between system timing and control quality is a key issue to consider across the control design and computer implementation phases in an integrated manner. We present such an integrated framework for scheduling, controller synthesis, and quality optimization for distributed embedded control systems. At runtime, an embedded control system may need to adapt to environmental changes that affect its workload and computational capacity. Examples of such changes, which inherently increase the design complexity, are mode changes, component failures, and resource usages of the running control applications. For these three cases, we present trade-offs among control quality, resource usage, and the time complexity of design and runtime algorithms for embedded control systems. The solutions proposed in this thesis have been validated by extensive experiments. The experimental results demonstrate the efficiency and importance of the presented techniques.

A presente dissertação tem por objetivo discutir a importância de uma postura resiliente para a busca do urbanismo sustentável. O termo \"sustentável\" e suas variantes passaram por um desgaste nas últimas décadas, formando uma barreira prejudicial à sua aplicação efetiva. A \"resiliência\", surge, então, como uma forma de revisitar a questão, através de um conceito oriundo da física, que possibilita conceber uma transposição teórica para a arquitetura e o urbanismo, disciplinas nas quais o tema pode colaborar na formulação de novas ferramentas e conceitos aplicáveis ao planejamento e projeto. Almeja-se, através da sua conceituação teórica, contribuir para a elaboração de uma postura resiliente e promover o termo \"resiliência urbana\" em direção ao enfrentamento da crise urbana, ocasionada pelo crescimento vertiginoso da urbanização mundial e da consequente aglomeração populacional nas cidades. Nos países em desenvolvimento, essa abordagem pode ser de grande utilidade, dado que a crise urbana é fortalecida pelo avanço da informalidade e pela formação de novos tecidos urbanos às margens do planejamento. O conceito de resiliência, neste caso, possibilita uma discussão voltada às questões de espontaneidade, improvisos, constantes mudanças e transformações, inerentes à condição urbana, se discutido dentro de uma abordagem de Sistemas Adaptativos Complexos. Para tanto, elaborou-se uma análise reflexiva, a fim de aferir a transferência da teoria para prática, a partir de três projetos urbanos já implantados: as intervenções em torno da Línea K, em Medellín, Colômbia, o sistema teleférico do Complexo do Alemão e o Parque Sitiê, ambos na cidade do Rio de Janeiro. A partir daí, pôde-se constatar que a visão sistêmica adaptativa e complexa da resiliência traz a possibilidade de promover a inter-relação entre sociedade, economia e ambiente na construção do meio urbano e, assim, encorajar uma nova postura frente a difusão de um Urbanismo Sustentável. / The present dissertation aims to discuss the importance of a resilient posture in the search for a sustainable urbanism. The term \"sustainable\" and its variants have gone through a wear and tear through the last few decades, forming a barrier which prejudices its effective application. The \"resilience\" term then appears as a way of revisiting this matter, through a concept derived from physics, that allows a theoretical transposition to architecture and urbanism disciplines in which the subject can cooperate in the formulation of new tools and concepts that can be applied into planning and project design process. Over the theoretical conception, it is intended the contribution on the elaboration of a resilient attitude and therefore promotes the term \"urban resilience\" towards the current urban crisis, caused by the dramatical growth of the world urbanization and the consequent population cluster within cities. In developing countries, the approach can be very useful, given that the urban crisis is strengthened by the rise of informality and the formation of new urban networks at the edge of planning actions. The concept of resilience, in this case, enables a discussion focused on spontaneity issues, improvisations, changes and transformations, inherent to the urban condition, discussed within a Complex Adaptive Systems approach. However to elaborate a reflexive analysis it is necessary to verify the transformation of theory into practice from three urban projects already implemented: Line K\'s urban interventions in Medellín, Colombia, cable car system at Alemão Complex and Sitiê Park, both in Rio de Janeiro, Brazil. In conclusion, an adaptive and complex systemic view of resilience has the potential to promote an interrelationship between society, economy and environment during the construction of an urban environment and therefore encourage a new attitude towards the diffusion of Sustainable Urbanism.

Nos travaux sont menés dans le cadre des architectures logicielles pour des applications interactives dont le principe général d’exécution adaptative a été défini au sein du laboratoire. Nous nous plaçons dans l’hypothèse où une application interactive est contextualisée au moyen de situations. L’utilisateur exécute des actions dans le contexte de situations successives pour avancer dans l’application interactive jusqu’à atteindre un ou plusieurs objectifs prédéfinis par le concepteur. Au cours de son déroulement, il se peut que l’utilisateur ne puisse plus continuer selon la logique du concepteur à cause des blocages du système ou une insuffisance de données pour poursuivre la logique d’exécution. Pour y remédier, un système d’aide à la décision est indispensable pour permettre au système et/ou à l’utilisateur de faire un choix adapté au contexte pour poursuivre l’exécution de l’application. Nous proposons d’améliorer le processus de décision en utilisant les traces des exécutions précédentes. Pendant l’exécution de l’application, un système à base de traces (système de gestion de traces) va collecter toutes les traces générées par l’utilisateur et les traces d’activité (les logs) au cours de l’interaction avec le système. Les contributions de nos travaux se situent à plusieurs niveaux : la conception d’un algorithme à base de traces pour la pondération des critères de décision ; la conception d’un algorithme de détermination des alternatives ; la définition et la formalisation des logiques de choix de l’utilisateur (utilisation de la logique subjective) et du système (PROMETHEE II à base de traces) pour classer les alternatives et l’agrégation des différents choix pour suggérer à l’utilisateur un choix final à exécuter. Un cas d’étude Tamagotchi est présenté pour valider nos contributions. / Our work deals with software architectures for adaptive interactive applications. We assume that one application is structured with contextual interaction sequences called situations. Users perform actions in successive situations to reach one or more predefined designer’s objectives. During its execution, it could happen that the user cannot fulfil designer’s logic because of some system’s blockings or missing data. Our challenge is to propose a method that chooses the most appropriate situation according to the given one. We propose to improve the decision-making process by using the generated traces during previous executions. These traces represent users’ interactions and system activity logs. A trace-based system collects and manages all users’ generated traces (logs). Our main contributions are: the design of a trace-based algorithm for criteria weighting; the design of an alternatives determination algorithm; the design and the formalisation of the users’ choice (using the trace-based subjective logic) and the system’s choice (using the trace-based PROMETHEE II) to classify all the identified alternatives and the aggregation of different choices to suggest to the user the right option to follow. A Tamagotchi case study is presented to validate our contributions.

The merging of business and information technology (IT) strategies, effectively becoming a Digital Business Strategy (DBS), is changing the way that organisations have to leverage resources to create differential value. Due to the DBS being such a novice idea, there is no clear understanding of what the DBS is, what its characteristics and boundaries are, how it impacts alignment between business and IT, and how it impacts organisational performance. Without this understanding, organisations leveraging a DBS run the risk of launching technological initiatives or making organisational changes that are disjointed from their strategic direction. These misaligned efforts may result in unrealised strategy and unsatisfactory organisational performance. The purpose of this study was to define the boundaries and characteristics of the DBS, provide a definition of a DBS and to establish if the DBS has a positive effect on organisational performance. To examine the DBS, it was observed in its natural habitat, through a single case study approach, focusing on an organisation that has been leveraging a DBS as part of their digital journey. The organisation is a South African based financial services provider and is a subsidiary of a larger financial services provider. In this study, the DBS was observed from an intellectual, operational, social and cultural alignment perspective, using a combination of the Strategic Alignment Model (SAM) and the Complex Adaptive System (CAS) frameworks. This study subscribed to a mixed-method approach which included both qualitative and quantitative research techniques. Staff providing input into this study included senior, middle, junior and non-management employees. The study was conducted over a period of thirteen months. The findings from both the qualitative and quantitative data suggest that to leverage a DBS the organisation must be concerned with more than just leveraging digital resources. For instance, organisations must focus on customer and staff empowerment, use customer and industry-related information to create opportunistic and competitive decision-making opportunities, and create a change-ready culture where bold experimentation and failing forward is embraced. Researchers and practitioners alike can use the findings of this case study as lessons on how to leverage organisational resources in the context of the DBS.

Implementation of electronic health records (EHRs) is a driver for the improvement of health care and the reduction of health care costs. Developing countries face substantial challenges in adopting EHRs. The complex adaptive system conceptual framework was used to guide this single case study to explore strategies that health care leaders used to successfully implement the EHR system. Data were collected from 6 health care leaders from an island in the Caribbean using a semistructured interview technique. Data were analyzed using the Bengtsson's 4-stage data analysis process, which includes decontextualization, recontextualization, categorization, and compilation. The results of the study yielded 5 main themes: training, increased staffing, monitoring, identifying organizational gaps, and time. The implications of the study for positive social change include the potential to improve the standards of care provided to promote improved patient outcomes by using the strategies identified in this study to successfully implement the EHR system.