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Target Tracking and Data Fusion with Cooperative IMM-based AlgorithmHsieh, Yu-Chen 26 August 2011 (has links)
In solving target tracking problems, the Kalman filter (KF) is a systematic estimation algorithm. Whether the state of a moving target adapts to the changes in the observations depends on the model assumptions. The interacting multiple model (IMM) algorithm uses interaction of a bank of parallel KFs by updating associated model probabilities. Every parallel KF has its model probability adjusted by the dynamic system. For moving targets of different dynamic linear models, an IMM with two KFs generally performs well. In this thesis, in order to improve the performance of target tracking and state estimation, multi-sensor data fusion technique will be used. Same types of IMMs can be incorporated in the cooperative IMM-based algorithm. The IMM-based estimators exchange with each other the estimates, model robabilities and model transition probabilities. A distributed algorithm for multi-sensor tracking usually needs a fusion center that integrates decisions or estimates, but the proposed cooperative IMM-based algorithm does not use the architecture. Cooperative IMM estimator structures exchange weights and estimates on the platforms to avoid accumulation of errors. Performance of data fusion may degrade due to different kinds of undesirable environmental effects. The simulations show that an IMM estimator with smaller measurement noise level can be used to compensate the other IMM, which is affected by larger measurement noise. In addition, failure of a sensor will cause the problem that model probabilities can not be updated in the corresponding estimator. Kalman filters will not be able to perform state correction for the moving target. To tackle the problem, we can use the estimates from other IMM estimators by adjusting the corresponding weights and model probabilities. The simulations show that the proposed cooperative IMM structure effectively improve the tracking performance.
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Kolektivizace zemědělství - Sušicko a Horažďovicko (1949-1959) / The collectivization of agriculture - Sušicko and Horažďovicko (1949-1959)ŠMÍD, Jan January 2007 (has links)
The collectivization of agriculture, or in other words, the process of village socialization has become a term that is synonomous for revolutionary changes to the lives of farmers, villages, and the entire countryside. For the older generation, its rememberance illicits mixed emotions; for the younger gereration, it is only a foggy resonance of the beginning of the path towards socialism.The collectivization of Agriculture can be evaluated by several criteria and points of view, whereas by refering to one of them we can characterize this era as the period of mass illegality.And it is this mass illegality that is the major concern of the diploma work. It aims to examine the impact of the collectivization policy on the rural inhabitants and the ensuing reactions as it is rarely studied by regional historiography {--} it is not available or is only available to a limited extent. From my point of view, this interaction is best described by the records of the criminal agenda of Sušice and Horažďovice court from 1949 to 1959; they also form the basis of my thesis.This thesis is focused not just on the general features of collectivization with regard to the mentioned regions, but to a considerable extent, it focuses on concrete examples. This thesis and peoples responses thus attempts, in part, to turn this work into a testimony of our recent history.
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Examining Cooperative System Responses Against Grid Integrity AttacksParady, Alexander D 01 January 2022 (has links)
Smart grid technologies are integral to society’s transition to sustainable energy sources, but they do not come without a cost. As the energy sector shifts away from a century’s reliance on fossil fuels and centralized generation, technology that actively monitors and controls every aspect of the power infrastructure has been widely adopted, resulting in a plethora of new vulnerabilities that have already wreaked havoc on critical infrastructure. Integrity attacks that feedback false data through industrial control systems, which result in possible catastrophic overcorrections and ensuing failures, have plagued grid infrastructure over the past several years. This threat is now at an all-time high and shows little sign of cooling off.
To combat this trajectory, this research explores the potential for simulated grid characteristics to examine robust security measures by use of a cyber-physical system (CPS) testbed constructed across the University of Central Florida (UCF) Resilient, Intelligent and Sustainable Energy Systems (RISES) Lab Cluster. This thesis explores hypothesized defense mechanisms and awareness algorithms to protect against unforeseen vulnerabilities brought on by grid attacks that will test the boundaries of commercial cybersecurity standards. Through an extensive probe across proposed defenses and vulnerability analysis of industrial systems, a blueprint for future research is outlined that will yield results that have the potential to ripple improvements across the power sector. The sanctity of critical infrastructure is of the highest priority for global powers. As such, this research bolsters the tools at the disposal of international entities and seeks to protect the ever-expanding lifestyle that reliable access to energy provides.
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Política governamental de energia substitutiva - cana de açúcar: do Pro-álcool ao etanol - 1979-2009 - um estudo de caso: região noroeste do Rio Grande do Sul / Governamental policy of substitutive energy. Sugar Cane: from Pro Alcohol to Etanol. (1979-2009). A Case Study: the northweet region of Rio Grande do SulFlores, Nelza 14 October 2010 (has links)
Este trabalho teve como objetivo pesquisar, à luz do pensamento de Celso Furtado e de especialistas, como Bautista Vidal, as políticas substitutivas energéticas, em especial as relativas à produção de álcool. Nesse contexto, enfoca um estudo de caso na Região Noroeste do Rio Grande do Sul, sobre pequenas propriedades rurais que atuam de modo cooperado para produzir em sistemas integrados, alimentos, energias renováveis e serviços ambientais. Pretende-se mostrar a importância desse modelo, não só para os municípios onde atuam as cooperativas estudadas, como também sua aplicabilidade em outros municípios, de acordo com as suas especificidades regionais, para atender a crescente demanda por um combustível limpo e renovável, dentre eles o álcool, bem como para diminuir as desigualdades regionais, ampliar a produção de alimentos e ainda, para criar mecanismos que possibilitem ao pequeno produtor rural deixar de ser apenas fornecedor de matéria prima. / This work intends to research - according the views of Celso Furtado and Bauptista Vidal the alternative policies of energy particularly to alcohol output. Emphasis is put on the Northwest Region of Rio Grande do Sul where cooperative small-sized proprietors produce integrated activities with food, crops, renewable energies and environment services. It is an attempt to show the importance of this model to countries and cooperative activities. It respects their local particularities in order to satisfy a growing demand for clean and renewable combustible, specially alcohol, contributing to reduce regional inequalities. It allows to expand food output and engendering mechanisms to promote small rural producer beyond the condition of raw materials supplier.
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Política governamental de energia substitutiva - cana de açúcar: do Pro-álcool ao etanol - 1979-2009 - um estudo de caso: região noroeste do Rio Grande do Sul / Governamental policy of substitutive energy. Sugar Cane: from Pro Alcohol to Etanol. (1979-2009). A Case Study: the northweet region of Rio Grande do SulNelza Flores 14 October 2010 (has links)
Este trabalho teve como objetivo pesquisar, à luz do pensamento de Celso Furtado e de especialistas, como Bautista Vidal, as políticas substitutivas energéticas, em especial as relativas à produção de álcool. Nesse contexto, enfoca um estudo de caso na Região Noroeste do Rio Grande do Sul, sobre pequenas propriedades rurais que atuam de modo cooperado para produzir em sistemas integrados, alimentos, energias renováveis e serviços ambientais. Pretende-se mostrar a importância desse modelo, não só para os municípios onde atuam as cooperativas estudadas, como também sua aplicabilidade em outros municípios, de acordo com as suas especificidades regionais, para atender a crescente demanda por um combustível limpo e renovável, dentre eles o álcool, bem como para diminuir as desigualdades regionais, ampliar a produção de alimentos e ainda, para criar mecanismos que possibilitem ao pequeno produtor rural deixar de ser apenas fornecedor de matéria prima. / This work intends to research - according the views of Celso Furtado and Bauptista Vidal the alternative policies of energy particularly to alcohol output. Emphasis is put on the Northwest Region of Rio Grande do Sul where cooperative small-sized proprietors produce integrated activities with food, crops, renewable energies and environment services. It is an attempt to show the importance of this model to countries and cooperative activities. It respects their local particularities in order to satisfy a growing demand for clean and renewable combustible, specially alcohol, contributing to reduce regional inequalities. It allows to expand food output and engendering mechanisms to promote small rural producer beyond the condition of raw materials supplier.
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DIFFERENTIAL CODE SHIFTED REFERENCE IMPULSE-BASED COOPERATIVE UWB COMMUNICATION SYSTEMAmjad, Shoaib, Malhi, Rohail Khan, Burhan, Muhammad January 2013 (has links)
Cooperative Impulse Response – Ultra Wideband (IR-UWB) communication is a radio technology very popular for short range communication systems as it enables single-antenna mobiles in a multi-user environment to share their antennas by creating virtual MIMO to achieve transmit diversity. In order to improve the cooperative IR-UWB system performance, we are going to use Differential Code Shifted Reference (DCSR). The simulations are used to compute Bit Error Rate (BER) of DCSR in cooperative IR-UWB system using different numbers of Decode and Forward relays while changing the distance between the source node and destination nodes. The results suggest that when compared to Code Shifted Reference (CSR) cooperative IR-UWB communication system; the DCSR cooperative IR-UWB communication system performs better in terms of BER, power efficiency and channel capacity. The simulations are performed for both non-line of sight (N-LOS) and line of sight (LOS) conditions and the results confirm that system has better performance under LOS channel environment. The simulation results also show that performance improves as we increase the number of relay nodes to a sufficiently large number. / +923214674079 , +923234155044
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Invariance and symbolic control of cooperative systems for temperature regulation in intelligent buildings / Invariance et contrôle symbolique de systèmes coopératifs pour la régulation de température dans les bâtiments intelligentsMeyer, Pierre-Jean 24 September 2015 (has links)
Cette thèse fournit de nouvelles stratégies de contrôle pouvant s'attaquer aux phénomènes hétérogènes et non-linéaires qui décrivent la régulation de la température dans les bâtiments afin d'obtenir un compromis entre le confort et l'efficacité énergétique. Nous nous intéressons donc au contrôle robuste de systèmes coopératifs avec perturbations bornées. Nous résolvons d'abord ce problème grâce à la notion d'intervalle invariant contrôlé robuste, décrivant un ensemble dans lequel l'état peut être maintenu quelle que soit la valeur des perturbations. Une seconde approche décrit des méthodes symboliques pour la synthèse d'un contrôleur discret sur une abstraction finie du système, réalisant une spécification de sûreté associée à l'optimisation des performances. Nous présentons d'abord une méthode symbolique centralisée utilisant les dynamiques du système correspondant au modèle physique. Pour résoudre ses limitations en termes de passage à l'échelle, nous considérons une approche compositionnelle où les méthodes symboliques d'abstraction et de synthèse sont appliquées à des descriptions partielles du système, sous des obligations de type assume-guarantee supposant que la sûreté est satisfaite pour tous les états non-contrôlés. Dans la dernière partie, les contrôleurs présentés sont combinés et évalués dans le cadre d'une régulation de température pour un bâtiment expérimental équipé de la solution UnderFloor Air Distribution. / This thesis provides new control strategies that deal with the heterogeneous and nonlinear dynamics describing the temperature regulation in buildings to obtain a tradeoff between comfort and energy efficiency. We thus focus on the robust control of cooperative systems with bounded disturbances. We first solve this problem with the notion of robust controlled invariant interval, which describes a set where the state can be maintained for any value of the disturbances. A second approach provides dedicated symbolic methods to synthesize a discrete controller on a finite abstraction of the system, realizing safety specifications combined with a performance optimization. We first present a centralized symbolic method using the system dynamics provided by the physical model. To address its limitation in terms of scalability, a compositional approach is considered, where the symbolic abstraction and synthesis methods are applied to partial descriptions of the system under the assume-guarantee obligation that the safety specification is realized for all uncontrolled states. In the final part, the proposed controllers are combined and evaluated on the temperature regulation for an experimental building equipped with UnderFloor Air Distribution.
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Méthode collaborative de segmentation et classification d'objets à partir d'images de télédétection à très haute résolution spatiale / Collaborative method of segmentation and classification of objects from remote sensing images with very high spatial resolutionSellaouti, Aymen 16 September 2014 (has links)
Avec l’avènement des images satellitaires à très haute résolution, les approches pixelliques ne donnant plus entière satisfaction ont été remplacées par les approches objets. Cependant, ces approches restent tributaires de la première étape qui permet le passage du pixel vers l’objet, à savoir l’étape de construction. L’architecture séquentielle de ces approches fait que les erreurs de l’étape de construction se répercutent sur l’étape d’identification. Il devient donc primordial de passer de cette architecture séquentielle vers une architecture itérative permettant la collaboration entre les étapes de construction et d’identification. Dans le cadre de cette thèse, nous nous sommes concentrés sur l’étude de l’étape de construction(i.e., la segmentation) comme base de départ pour les approches proposées. Nous avons proposé deux approches objets basées sur les techniques de segmentation les plus propices à la collaboration, à savoir les techniques régions et les techniques collaboratives région/contour. La première approche proposée se base sur une croissance sémantique hiérarchique. Elle permet de combiner les algorithmes de croissance de régions et les approches d’analyse d’images orientées objets. La croissance étant spécifique à la classe du germe de départ, nous avons proposé deux adaptations de l’approche sur les objets les plus rencontrés dans le contexte urbain, à savoir, les routes et les bâtiments. La deuxième approche utilise un algorithme évolutionnaire local permettant un paramétrage local des différents agents régions et contours évoluant au sein d’un système multi-agents. / Object based image analysis is a rising research area in remote sensing. However, existing approaches heavily rely on the object construction process, mainly due to the lack of interaction between the two steps, i.e., Construction and identification.In this thesis, we focused on the study of the construction phase (i.e., segmentation) as a basis for the proposed approaches. The first proposed approach is based on a hierarchical semantic growth. This approach allows merging region-growing algorithms and Object Based Image Analysis approaches. Due to the dependency of the semantic growth on the seed class, we propose two adaptations of the approach on the most used class in the urban context, i.e., roadsand buildings. The second approach benefits of both multi-agent systems and genetic algorithms characteristics. It overcomes the threshold’s dependency of the proposed cooperative multi-agent system between an edge approach and a region approach. The genetic algorithm is used to automatically find building extraction parameters for each agent based on expert knowledge. The proposed approaches have been validated on a very high-resolution image of the urban area of Strasbourg.
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Cooperative Communication In Store And Forward Wireless Networks Using Rateless CodesBansal, Gaurav 05 1900 (has links) (PDF)
In this thesis, we consider a cooperative relay-assisted communication system that uses rateless codes. When multiple relays are present, the relay with the highest channel gain to the source is the first to successfully decode a message from the source and forward it to the destination. Thus, the unique properties of rateless codes ensure that both rate adaptation and relay selection occur without the transmitting source or relays acquiring instantaneous channel knowledge. We show that in such cooperative systems, buffering messages at relays significantly increases throughput. We develop a novel analysis of these systems that combines the communication-theoretic aspects of cooperation over fading channels with the queuing-theoretic aspects associated with buffering. Closed-form expressions are derived for the throughput and end-to-end delay for the general case in which the channels between various nodes are not statistically identical. Results are also shown for the benchmark system that does not buffer messages.
Though relay selection combined with buffering of messages at the relays substantially increases the throughput of a cooperative network, it also increases the end-to-end delays due to the additional queuing delays at the relay nodes. In order to overcome this, we propose a novel method that exploits a unique property of rateless codes that enables a receiver to decode a message from non-contiguous and unordered portions of the received signal. In it, each relay, depending on its queue length, ignores its received coded bits with a given probability. We show that this substantially reduces the end-to-end delays while retaining almost all of the throughput gain achieved by buffering. In effect, the method increases the odds that the message is first decoded by a relay with a smaller queue. Thus, the queuing load is balanced across the relays and traded off with transmission times. We derive conditions for the stability of this system when the various channels undergo fading. Despite encountering analytically intractable G/GI/1 queues in our system, we also gain insights about the method by analyzing a similar system with a simpler model for the relay-to-destination transmission times.
Next we combine the single relay selection scheme at the source with physical layer power control at the relays (due to the diversity provided by the rateless codes, power control at the source is not needed). We derive an optimal power control policy that minimizes the relay to destination transmission time. Due to its computational and implementation complexity, we develop another heuristic easily implementable near optimal policy. In this policy, power allocated turns out to be inversely proportional to the square root of channel gain. We also see that this policy performs better than the channel inversion policy. Our power control solution substantially decreases the mean end-to-end delays with a marginal increase in throughput also. Finally, we combine bit dropping with power control at the relays which further improves the system performance.
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Predictable and Scalable Medium Access Control for Vehicular Ad Hoc NetworksSjöberg Bilstrup, Katrin January 2009 (has links)
<p>This licentiate thesis work investigates two medium access control (MAC) methods, when used in traffic safety applications over vehicular <em>ad hoc</em> networks (VANETs). The MAC methods are carrier sense multiple access (CSMA), as specified by the leading standard for VANETs IEEE 802.11p, and self-organizing time-division multiple access (STDMA) as used by the leading standard for transponders on ships. All vehicles in traffic safety applications periodically broadcast cooperative awareness messages (CAMs). The CAM based data traffic implies requirements on a predictable, fair and scalable medium access mechanism. The investigated performance measures are <em>channel access delay</em>, <em>number of consecutive packet drops</em> and the <em>distance between concurrently transmitting nodes</em>. Performance is evaluated by computer simulations of a highway scenario in which all vehicles broadcast CAMs with different update rates and packet lengths. The obtained results show that nodes in a CSMA system can experience <em>unbounded channel access delays</em> and further that there is a significant difference between the best case and worst case channel access delay that a node could experience. In addition, with CSMA there is a very high probability that several <em>concurrently transmitting nodes are located close to each other</em>. This occurs when nodes start their listening periods at the same time or when nodes choose the same backoff value, which results in nodes starting to transmit at the same time instant. The CSMA algorithm is therefore both <em>unpredictable</em> and <em>unfair</em> besides the fact that it <em>scales badly</em> for broadcasted CAMs. STDMA, on the other hand, will always grant channel access for all packets before a predetermined time, regardless of the number of competing nodes. Therefore, the STDMA algorithm is <em>predictable</em> and <em>fair</em>. STDMA, using parameter settings that have been adapted to the vehicular environment, is shown to outperform CSMA when considering the performance measure <em>distance between concurrently transmitting nodes</em>. In CSMA the distance between concurrent transmissions is random, whereas STDMA uses the side information from the CAMs to properly schedule concurrent transmissions in space. The price paid for the superior performance of STDMA is the required network synchronization through a global navigation satellite system, e.g., GPS. That aside since STDMA was shown to be scalable, predictable and fair; it is an excellent candidate for use in VANETs when complex communication requirements from traffic safety applications should be met.</p>
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