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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.
31

動態系統與生育率及死亡率的估計 / Using dynamic system to model fertility and mortality rates

李玢 Unknown Date (has links)
人口統計學家在傳統上習慣將人口的種種變化視為時間的函數,皆試圖以決定型(deterministic)的函數來刻劃,例如:1825年Gompertz提出的死力法則、1838年Verhulst以羅吉斯函數描述人口成長。近年則傾向於逐項(item-by-item)分析各種可能因素,例如:1992年Lee-Carter提出的死亡率模型、目前英國實務上使用的Renshaw與Haberman(2003)提出改善Lee-Carter模型的Reduction Factor模型、加入世代(Cohort)因素的Age-Period-Cohort模型等。但台灣地區近年來生育率與死亡率皆不斷下降,且有隨著時間而變化加劇的傾向,使得以往使用的模型不易捕捉變化。 本文以另一個角度思考生育與死亡變化,將台灣人口視為一隨時間變化的動態系統,使用微分方程來刻劃,找出此動態系統的背後所隱含的規則。人口動態系統的變化,主要來源是出生、死亡與遷移,在建模的過程中,我們先各別針對其中一項,在其他條件不變的情況下,以常微分方程建模,之後再同時考慮各項變動,以偏微分方程建模,找出台灣人口變化的模型。在本文中,我們先介紹使用微分方程模型分別配適與估計出生與死亡。 由台灣地區人口統計資料顯示,不論總生育率或各年齡組的死亡率都有逐漸下降的趨勢,但是每年之間的震盪很大,因此我們提出「二次逼近法」,從出生或死亡對時間的變化率與曲度來估計生育率與死亡率,對於此種震盪幅度較大的資料,可以得到頗精確的估計。唯在連續幾年資料呈現近似線性上升或下降處,非線性的模型容易出現較大的估計誤差,針對此問題我們也提出一些可能的修正方法,以降低整體的模型誤差率。 / Conventionally the change of population is considered as a function of time and described by using deterministic functions. The well-known examples are Gompertz law of mortality (1825) and Verhulst’s logistic growth model (1838). Recently demographers favor stochastic models when analyzing factors in an item-by-item fashion. Since 1992, Lee-Carter model is a most commonly used stochastic model in demographic studies. But empirical studies indicate that the rapid declines in both fertility and mortality rates are against the assumptions of Lee-Carter model. In this study we treat Taiwan population as a dynamic system which changes over time and characterize it by differential equations. Since the changes are from birth, death and migration, we first separately build models using ordinary differential equations. Afterwards the model of Taiwan population can be built by using partial differential equations considering the three main factors simultaneously. Total fertility and age-specific mortality rates in Taiwan decline over time but with shakes between years. Consequently we propose‘parabola approximation method’and apply it to velocity and acceleration of birth or death to solve the differential equations of Taiwan fertility and mortality. Empirical study shows the method allows us to get accurate estimates of mortality and fertility when the data change a lot in a short period of time. But we found the model may over-fit the data at some time point where the function does not seem to be very continuous.
32

Modelagem de sistemas de proteção técnica contra incêndio em edifícios inteligentes através de rede de Petri. / Modeling of fire protection systems in intelligent building through Petri net.

Kaneshiro, Percy Javier Igei 01 December 2006 (has links)
O sistema de proteção técnica contra incêndio (SPTCI) é um dos principais sistemas que compõem o edifício inteligente (EI), pois a eficiência do seu funcionamento afeta diretamente a segurança das pessoas e o patrimônio do prédio. O SPTCI é composto de diferentes dispositivos, estratégias de controle e atua segundo legislação específica. Devido à complexidade do SPTCI, torna-se fundamental uma modelagem adequada que permita verificar a dinâmica do sistema e sua relação com outros sistemas prediais. Neste contexto, este trabalho propõe um procedimento para a modelagem e análise de estratégias de controle para o SPTCI, integrado com outros sistemas prediais dentro do contexto de EI. A abordagem considerada para este propósito baseia-se na teoria dos sistemas a eventos discretos, na aplicação de técnicas derivadas da rede de Petri e em técnicas de análise através de simulação discreta. Com esta abordagem são desenvolvidos modelos do sistema de controle do SPTCI onde é considerada a sua relação com outros sistemas prediais. Particularmente, explora-se as extensões da rede de Petri como as técnicas Production Flow Schema e Mark Flow Graph. Um estudo de caso é apresentado para ilustrar as principais características deste procedimento. / From the point of view of property damage and personal security, the fire protection system (FPS) is one of the most important systems in an intelligent building (IB). The FPS is composed of several devices and control strategies. Furthermore, it must act in accordance with specific laws. As a consequence the design of FPSs is a complex task and it is very important to provide an adequate model that supports the verification of the FPS dynamics and its integration with others building systems, facilitating its test and validation. In this context, this work proposes a procedure to model in a systematic and rational way a FPS in the IB context. Considering the nature of the structure and processes of FPS the approach is based on the discrete event dynamic system theory and the application of the Petri net. Then, the models the FPS control system and the controlled plant must include its integration with other building systems. Particularly, it explores Petri net extensions such as Production Flow Schema and Mark Flow Graph techniques. Through an example it is illustrated the main aspects of the proposed procedure.
33

Relations entre l’état d’une ressource et son exploitation via la compréhension et la formalisation des interactions de socio-écosystèmes. Application à la palourde japonaise (Venerupis philippinarum) du bassin d’Arcachon. / Relationships between stock status and its exploitation via comprehension and formalization of socio-ecosystems interactions. Application to Manila clam (Venerupis philippinarum) population of Arcachon Bay.

Caill-Milly, Nathalie 11 December 2012 (has links)
Composante importante de l’écosystème marin benthique, les bivalves exploités sont surtout situés dans la zone littorale dont les caractéristiques spatiales et temporelles engendrent des fluctuations populationnelles naturelles et contribuent à de fortes variations de biomasse et de structure démographique s’ajoutant aux effets d’activités anthropiques. La compréhension des interactions entre l’espèce, son environnement et son exploitation est cruciale. Leur formalisation, y compris pour la gestion, passe par le développement de modèles mathématiques qui visent à décrire le fonctionnement du système, expliquer des phénomènes observés en termes de cause à effet ou prédire l’effets de nouvelles causes. Espèce introduite en France dans les années 1980, la palourde japonaise (Venerupis philippinarum) constitue une ressource économique importante pour des zones littorales. Pour le bassin d’Arcachon, les pêcheurs à pied professionnels capturent quelques 600 tonnes par an. Outre la réglementation européenne qui fixe une taille minimale de capture, des mesures de gestion complémentaires sont établies par les structures professionnelles locales de la pêche dans un cadre de cogestion impliquant ces structures, scientifiques et administration.Ce travail de thèse s’inscrit dans ce contexte en intégrant les traits d’histoire de vie de la population dans le modèle de simulation utilisé à des fins de gestion. A l’échelle locale, l’analyse de forme conventionnelle basée sur des mesures métriques et pondérales établit des relations d’allométrie entre des paires de descripteurs avec un changement significatif de morphologie à partir d’une longueur de 16-20 mm. La variabilité phénotypique intra-site s’articule en trois patrons morphologiques. Dans le bassin d’Arcachon, le caractère globuleux, décrit pour la première fois ici, est associé à de faibles densités et à de fortes proportions d’individus affectés par la maladie du muscle marron, maladie émergente sur le bassin. A l’échelle de la façade atlantique française, trois ratios morphométriques (indices d’élongation, de densité de la valve et de poids de la valve sur sa longueur) discriminent les populations des sites nord (Banc du Guer, golfe du Morbihan) de celles des sites sud (Bellevue, bassin d’Arcachon). Une corrélation significative entre ces ratios et les conditions trophiques approchées par la concentration en chlorophylle a ainsi qu’un lien entre l’indice de densité de la valve et le pourcentage de températures comprises entre 12 et 20°C sont démontrés. La complexité des facteurs intervenant sur la morphologie intra et inter-sites laisse supposer l’intervention d’autres facteurs comme la nature du substrat, ce qui est conforté par des premières analyses de contours. Les travaux ont confirmé l’importance de la température sur les variables d’état du stock notamment lors de la période de reproduction. Pour ces mêmes variables, un rôle majeur des ressources trophiques a aussi été démontré avec des réponses différant selon les stades. Une partie de ces résultats a contribué à des modifications dans le modèle de simulation. Elles ont surtout concerné l’intégration de l’effet des ressources trophiques sur le recrutement, la révision de la production de juvéniles et des taux de croissance par classe de taille, la précision de données de captures et l’ajout d’un effet prix sur les stratégies de pêche. En parallèle à la validation du modèle, l’analyse de sensibilité a mis en évidence la sensibilité du modèle aux paramètres environnementaux et aux variables relatives aux stades les plus jeunes. Dans un contexte de cogestion, l’outil a été utilisé pour réaliser des projections sur le devenir de la population selon différents scénarios de gestion. Les différences de tendances d’évolution de la biomasse en réponse à ces dispositifs d’action ont servi aux gestionnaires pour la définition des mesures de gestion actuellement en vigueur. Au final, le modèle renforce la démarche participative engagée. / Significant component of the marine benthic ecosystem, exploited bivalves are mainly located inside the coastal area, which temporal and spatial features generate natural population fluctuations and contribute to considerable biomass and demographic structure changes added to anthropogenic activities’ effects (fishing, pollution,…). Understanding of the relationships between the species, its environment and its exploitation is crucial and their formalization, including for management purposes, requires development of mathematical models that aim at describing the functioning of the system, to explain the observed phenomenon in terms of cause and effect or predict effects of new causes. Originating from venerid culture trials carried out in France in the 80s, Manila clam (Venerupis philippinarum) is an important economic resource for coastal areas. Inside the Arcachon Bay, professional fishermen catch about 600 tonnes annually. Whereas the minimum legal harvest size is set by European legislation, complementary management measures are established by regional and departmental professional organizations in the framework of a co-management approach involving professional, scientists and administration. This doctoral thesis is part of this objective of co-management by integrating life history traits of the population in a simulation model used for management purposes. At local scale, conventional shape analysis methods using metric weights and measures establish allometric relationships between pairs of descriptors with a significant morphological change detected from a length of ca. 16-20 mm. Intra-site phenotypic variability is structured in three morphological patterns. Occurrence of globular character inside the Arcachon Bay, described here for the first time, is associated to low densities and to high proportions of individuals affected by brown muscle disease, an emerging disease in the Bay. At the scale of the French Atlantic coast, three morphological ratios (elongation, valve density and weight related to length indices) discriminate populations from northern (Banc du Guer and Morbihan Gulf) and southern sites (Bellevue and Arcachon Bay). Significant relationships between those ratios and trophic conditions expressed by chlorophyll a concentrations, as well as a link between weight surface ratios and percentage of seawater temperature ranging from 12 to 20°C are demonstrated. Complexity of factors involved in intrasite and intersite morphology suggests intervention of other factors such as sediment characteristics, which is supported by a first outlines analysis. This work confirmed the importance of seawater temperature on stock state variables particularly during the reproduction period. For those same variables, a major role of trophic conditions has also been demonstrated with answers depending on development stages. Part of this result contributed to modifications within the simulation model dedicated to this population. The modifications mainly concerned integration of trophic resources effect on recruitment level, juveniles’ production and growth rates per length class revision, accuracy of catches by professional fishermen and addition of a price effect on the fishing strategies. In conjonction with the model validation, the sensitivity analysis undertaken highlighted the sensitivity of the model to environmental parameters and to variables related to the younger stages. In a co-management context, this tool was used to perform projections on the future of the population according to various management scenarios. The differences in the patterns of biomass evolution in response to those action schemes were used by the stakeholders to identify management measures currently in force. In the end the model reinforces the engaged participatory process.
34

Modélisation dynamique de la signalisation cellulaire : aspects différentiels et discrets : application à la signalisation du facteur de croissance TGF-β dans le cancer / Dynamic modeling of cell signaling : differential and discrete aspects : application to the TGF-β growth factor in cancer

Andrieux, Goeffroy 18 July 2013 (has links)
La signalisation cellulaire regroupe l'ensemble des mécanismes biologiques permettant à une cellule de répondre de façon adaptée à son microenvironnement. Pour ce faire, de nombreuses réactions biologiques entrent en jeux avec un important enchevêtrement, créant ainsi un réseau dont le comportement s'apparente à un système complexe. Le compréhension de la réponse cellulaire à une stimulation passe par le développement conjoint des techniques d'acquisition de données, et des méthodes permettant de formaliser ces données dans un modèle. C'est sur ce dernier point que s'inscrivent les travaux exposés dans cette thèse. Nous présentons ici deux approches visant à répondre à des questions de natures différentes sur la signalisation cellulaire. Dans la première nous utilisons un modèle différentiel pour étudier le rôle d'un nouvel interactant dans la voie canonique du TGF-β. Dans la seconde nous avons exploré la combinatoire de la signalisation cellulaire en développant un formalisme discret basé sur les transitions gardées. Cette approche regroupe l'interprétation de la base de données Pathway Interaction Database dans un unique modèle dynamique de propagation du signal. Des méthodes de simulations et d'analyses inspirées des techniques de vérification de modèles telles que l'atteignabilité et l'invariance ont été développées. En outre, nous avons étudié la régulation du cycle cellulaire en réponse à la signalisation, ainsi que la régulation des gènes de notre modèle en comparaison avec des données d'expressions. / Cell signaling contains the whole biological mecanisms allowing the response of a cell to its microenvironnement in an adapted way. Many extremely intertwinned biological reactions are involved in a network that behaves as a complex system. The understanding of cell response requires the development of data acquisition technics and methods to formalize data into models. This point is the main drive of this thesis. We present here two approaches in order to analyse different granularities of cell signaling. In the first one, we used differential model to study the role of a new component of \tgf\ canonical pathway. In the second one, we explored the combinatorial complexity of cell signaling, developing a discrete formalism based on guarded transitions. In this approach, we interpreted the whole database Pathway Interaction Database into a single unified model of signal transduction. Simulation and analysis methods, such as reachability and invariance research, have been developed. The interests are presented through an application on cell cycle regulation by cell signaling, and a global analysis on the regulation of genes compared to experimental data.
35

Proposta de um indicador para monitorar a evolução da simbiose industrial em parques eco-industriais segundo a perspectiva de sistemas dinâmicos

Miriã Camargo Felicio 23 January 2013 (has links)
Os Parques Eco-Industriais (EIP - Eco-Industrial Park) surgiram como um novo modelo de organização espacial para arranjos industriais. Uma característica importante para um EIP é a adoção do conceito de simbiose industrial (SI), em que as empresas reutilizam resíduos em busca de um sistema fechado, diminuindo impacto ambiental. Há propostas para avaliar o fluxo de resíduos e a simbiose de um EIP por meio de indicadores detalhados em um determinado momento. Porém, trata-se de uma visão estática do parque na qual seria possível que os agentes implementassem mudanças para construir uma situação de sistema fechado ideal. Pesquisas recentes demonstram que essa abordagem enfrenta algumas limitações, uma vez que o processo de simbiose depende das decisões rotineiras e individuais de cada ator, empresários, técnicos e agenciadores, as quais podem alterar a dinâmica do fluxo de material no decorrer do tempo. A fim de contribuir, propõe-se um indicador de simbiose industrial diferente, elaborado segundo a abordagem do parque como um sistema dinâmico. Trata-se de uma ferramenta capaz de monitorar o nível de simbiose de um parque ao longo do tempo. Diferencia-se por permitir que a organização agenciadora possa implementar políticas de incentivo à simbiose industrial, influenciando nas decisões rotineiras dos diversos agentes do parque, em prol da simbiose. Empregaram-se estudos de caso, revisão sistemática da literatura e análise teórico-conceitual. Os primeiros resultados foram dois estudos de casos em parques que se autodenominavam EIPs, identificando oportunidades para a promoção da simbiose. O segundo resultado foi a proposta teórico-conceitual do Indicador de Simbiose Industrial (ISI) que pode ser utilizado como instrumento para o ambiente industrial dinâmico. Por fim, apresenta-se a análise das propriedades do indicador a partir de dados obtidos em um dos casos. Os resultados indicaram que o ISI pode identificar níveis de simbiose distintos para um mesmo parque, conforme sua evolução em direção a uma simbiose perfeita. A avaliação da coerência do ISI permitiu demonstrar sua capacidade em captar a ausência e a presença do processo de simbiose, atendendo as expectativas iniciais da construção do indicador. A avaliação do comportamento do ISI por meio da variação dos seus elementos permitiu analisar o indicador sob diferentes possibilidades, correspondendo positivamente às expectativas da pesquisa. Indica-se também várias questões que precisam ser verificadas para a validação do indicador e os próximos passos para torná-lo uma ferramenta útil para o gerenciamento de parques industriais interessados em aprimorar o seu nível de simbiose industrial. / The Eco-Industrial Parks (EIP - Eco-Industrial Park) emerged as a new model of spatial organization for industrial arrangements. An important feature for an EIP is the adoption of the concept of industrial symbiosis (IS), in which companies reuse waste to reach a closed system, reducing environmental impact. There are proposals to assess the waste stream and the symbiosis of an EIP through detailed indicators at a determined time. However, it is a static view of the park in which would be possible to the managers implement changes to construct a state of ideal closed system. Recent researches show that this approach faces some limitations, once the process symbiosis depends on the routine and individual decisions of the actors, managers, technicians and agents, which can alter the dynamics of the material flow through time. In order to contribute, it is proposed an different indicator of industrial symbiosis, prepared according to the approach of the park as a dynamic system. This is a tool that can monitor the level of symbiosis of a park during a determined time. This is different because allow the agent organization to implement policies to encourage industrial symbiosis influencing the routines decisions of the parks agents in favor of symbiosis. It was made case studies, systematic review of the literature and theoretical and conceptual analysis. The first results were two case studies in parks that called themselves EIPs, identifying opportunities to promote symbiosis. The second result was the proposed theoretical-conceptual Indicator Industrial Symbiosis (ISI) which can be used as a tool for the dynamic industrial environment. Finally, it shows the analysis of the indicator properties considering data obtained in one of the cases. The results indicated that the ISI can identify different levels of symbiosis for the same park as its evolution toward a perfect symbiosis. The assessment of the consistency of the ISI has demonstrated its ability to capture the absence and presence of the symbiosis process, confirming the expectations of the initial construction of the indicator. The performance evaluation of the ISI through the variation of its elements, allowed us to analyze the indicator under different possibilities, corresponding positively to the expectations of the research. Also, it indicates that several issues need to be checked to validate the indicator and the next steps to make it a useful tool for managing industrial parks interested in improving their level of industrial symbiosis.
36

Proposta de um indicador para monitorar a evolução da simbiose industrial em parques eco-industriais segundo a perspectiva de sistemas dinâmicos

Felicio, Miriã Camargo 23 January 2013 (has links)
Os Parques Eco-Industriais (EIP - Eco-Industrial Park) surgiram como um novo modelo de organização espacial para arranjos industriais. Uma característica importante para um EIP é a adoção do conceito de simbiose industrial (SI), em que as empresas reutilizam resíduos em busca de um sistema fechado, diminuindo impacto ambiental. Há propostas para avaliar o fluxo de resíduos e a simbiose de um EIP por meio de indicadores detalhados em um determinado momento. Porém, trata-se de uma visão estática do parque na qual seria possível que os agentes implementassem mudanças para construir uma situação de sistema fechado ideal. Pesquisas recentes demonstram que essa abordagem enfrenta algumas limitações, uma vez que o processo de simbiose depende das decisões rotineiras e individuais de cada ator, empresários, técnicos e agenciadores, as quais podem alterar a dinâmica do fluxo de material no decorrer do tempo. A fim de contribuir, propõe-se um indicador de simbiose industrial diferente, elaborado segundo a abordagem do parque como um sistema dinâmico. Trata-se de uma ferramenta capaz de monitorar o nível de simbiose de um parque ao longo do tempo. Diferencia-se por permitir que a organização agenciadora possa implementar políticas de incentivo à simbiose industrial, influenciando nas decisões rotineiras dos diversos agentes do parque, em prol da simbiose. Empregaram-se estudos de caso, revisão sistemática da literatura e análise teórico-conceitual. Os primeiros resultados foram dois estudos de casos em parques que se autodenominavam EIPs, identificando oportunidades para a promoção da simbiose. O segundo resultado foi a proposta teórico-conceitual do Indicador de Simbiose Industrial (ISI) que pode ser utilizado como instrumento para o ambiente industrial dinâmico. Por fim, apresenta-se a análise das propriedades do indicador a partir de dados obtidos em um dos casos. Os resultados indicaram que o ISI pode identificar níveis de simbiose distintos para um mesmo parque, conforme sua evolução em direção a uma simbiose perfeita. A avaliação da coerência do ISI permitiu demonstrar sua capacidade em captar a ausência e a presença do processo de simbiose, atendendo as expectativas iniciais da construção do indicador. A avaliação do comportamento do ISI por meio da variação dos seus elementos permitiu analisar o indicador sob diferentes possibilidades, correspondendo positivamente às expectativas da pesquisa. Indica-se também várias questões que precisam ser verificadas para a validação do indicador e os próximos passos para torná-lo uma ferramenta útil para o gerenciamento de parques industriais interessados em aprimorar o seu nível de simbiose industrial. / The Eco-Industrial Parks (EIP - Eco-Industrial Park) emerged as a new model of spatial organization for industrial arrangements. An important feature for an EIP is the adoption of the concept of industrial symbiosis (IS), in which companies reuse waste to reach a closed system, reducing environmental impact. There are proposals to assess the waste stream and the symbiosis of an EIP through detailed indicators at a determined time. However, it is a static view of the park in which would be possible to the managers implement changes to construct a state of ideal closed system. Recent researches show that this approach faces some limitations, once the process symbiosis depends on the routine and individual decisions of the actors, managers, technicians and agents, which can alter the dynamics of the material flow through time. In order to contribute, it is proposed an different indicator of industrial symbiosis, prepared according to the approach of the park as a dynamic system. This is a tool that can monitor the level of symbiosis of a park during a determined time. This is different because allow the agent organization to implement policies to encourage industrial symbiosis influencing the routines decisions of the parks agents in favor of symbiosis. It was made case studies, systematic review of the literature and theoretical and conceptual analysis. The first results were two case studies in parks that called themselves EIPs, identifying opportunities to promote symbiosis. The second result was the proposed theoretical-conceptual Indicator Industrial Symbiosis (ISI) which can be used as a tool for the dynamic industrial environment. Finally, it shows the analysis of the indicator properties considering data obtained in one of the cases. The results indicated that the ISI can identify different levels of symbiosis for the same park as its evolution toward a perfect symbiosis. The assessment of the consistency of the ISI has demonstrated its ability to capture the absence and presence of the symbiosis process, confirming the expectations of the initial construction of the indicator. The performance evaluation of the ISI through the variation of its elements, allowed us to analyze the indicator under different possibilities, corresponding positively to the expectations of the research. Also, it indicates that several issues need to be checked to validate the indicator and the next steps to make it a useful tool for managing industrial parks interested in improving their level of industrial symbiosis.
37

Using Auditory Modalities to Develop Rhythmic Competency in Children's Fundamental Movement Skills

Severy, Sally Suzanne 01 January 2016 (has links)
Physical education classrooms often have low levels of moderate to vigorous physical activity levels. This is a problem since many young elementary students are not building a foundation of fundamental movement skills necessary to be lifelong participants in physical activities. This study investigated how elementary physical education teachers used auditory modalities in their classrooms. The research question explored the emergence of rhythmic competency in fundamental movement skills to increase overall moderate to vigorous activity levels. This concurrent, mixed-methods, multiple case study used a constructivist paradigm using the schema and dynamic system theories as the underlying motor system theoretical framework. Two research sites were selected: a suburban Maryland public school system and a private liberal arts college located in the same county. The participants included 21 elementary physical education teachers and 6 physical education or exercise science majors from nationally recognized programs. Data were collected from a focus group, interviews, classroom observations, and a 10-item response Likert style survey designed for elementary physical education teachers to recognize current trends in the field of auditory modalities and rhythmic competency. The data were analyzed to identify auditory modality instructional methods for the emergence of rhythmic competencies. The results consisted of a list of best practices for use such as musical rhythms, verbal cues, and sound cues by physical education teachers and specialists. This research promotes positive social change by providing information for successfully planning interventions in the discipline of motor skill and rhythmic development that can lead to overall increased more-vigorous physical activity.
38

A Cognitive Radio Tracking System for Indoor Environments

Kushki, Azadeh 26 February 2009 (has links)
Advances in wireless communication have enabled mobility of personal computing services equipped with sensing and computing capabilities. This has motivated the development of location-based services (LBS) that are implemented on top of existing communication infrastructures to cater to changing user contexts. To enable and support the delivery of LBS, accurate, reliable, and realtime user location information is needed. This thesis introduces a cognitive dynamic system for tracking the position of mobile users using received signal strength (RSS) in Wireless Local Area Networks (WLAN). The main challenge in WLAN positioning is the unpredictable nature of the RSS-position relationship. Existing system rely on a set of training samples collected at a set of anchor points with known positions in the environment to characterize this relationship. The first contribution of this thesis is the use of nonparametric kernel density estimation for minimum mean square error positioning using the RSS training data. This formulation enables the rigorous study of state-space filtering in the context of WLAN positioning. The outcome is the Nonparametric Information (NI) filter, a novel recursive position estimator that incorporates both RSS measurements and a dynamic model of pedestrian motion during estimation. In contrast to traditional Kalman filtering approaches, the NI filter does not require the explicit knowledge of RSS-position relationship and is therefore well-suited for the WLAN positioning problem. The use of the dynamic motion model by the NI filter leads to the design of a cognitive dynamic tracking system. This design harnesses the benefits of feedback and position predictions from the filter to guide the selection of anchor points and radio sensors used during estimation. Experimental results using real measurement from an office environment demonstrate the effectiveness of proactive determination of sensing and estimation parameters in mitigating difficulties that arise due to the unpredictable nature of the indoor radio environment. In particular, the results indicate that the proposed cognitive design achieves an improvement of 3.19m (56\%) in positioning error relative to memoryless positioning alone.
39

A Cognitive Radio Tracking System for Indoor Environments

Kushki, Azadeh 26 February 2009 (has links)
Advances in wireless communication have enabled mobility of personal computing services equipped with sensing and computing capabilities. This has motivated the development of location-based services (LBS) that are implemented on top of existing communication infrastructures to cater to changing user contexts. To enable and support the delivery of LBS, accurate, reliable, and realtime user location information is needed. This thesis introduces a cognitive dynamic system for tracking the position of mobile users using received signal strength (RSS) in Wireless Local Area Networks (WLAN). The main challenge in WLAN positioning is the unpredictable nature of the RSS-position relationship. Existing system rely on a set of training samples collected at a set of anchor points with known positions in the environment to characterize this relationship. The first contribution of this thesis is the use of nonparametric kernel density estimation for minimum mean square error positioning using the RSS training data. This formulation enables the rigorous study of state-space filtering in the context of WLAN positioning. The outcome is the Nonparametric Information (NI) filter, a novel recursive position estimator that incorporates both RSS measurements and a dynamic model of pedestrian motion during estimation. In contrast to traditional Kalman filtering approaches, the NI filter does not require the explicit knowledge of RSS-position relationship and is therefore well-suited for the WLAN positioning problem. The use of the dynamic motion model by the NI filter leads to the design of a cognitive dynamic tracking system. This design harnesses the benefits of feedback and position predictions from the filter to guide the selection of anchor points and radio sensors used during estimation. Experimental results using real measurement from an office environment demonstrate the effectiveness of proactive determination of sensing and estimation parameters in mitigating difficulties that arise due to the unpredictable nature of the indoor radio environment. In particular, the results indicate that the proposed cognitive design achieves an improvement of 3.19m (56\%) in positioning error relative to memoryless positioning alone.
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Design Of An Integrated Hardware-in-the-loop Simulation System

Serdar, Usenmez 01 June 2010 (has links) (PDF)
This thesis aims to propose multiple methods for performing a hardware-in-the-loop simulation, providing the hardware and software tools necessary for design and execution. For this purpose, methods of modeling commonly encountered dynamical system components are explored and techniques suitable for calculating the states of the modeled system are presented. Modules and subsystems that enable the realization of a hardware-in-the-loop simulation application and its interfacing with external controller hardware are explained. The thesis also presents three different simulation scenarios. Solutions suitable for these scenarios are provided along with their implementations. The details and specifications of the developed software packages and hardware platforms are given. The provided results illustrate the advantages and disadvantages of the approaches used in these solutions.

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