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This dissertation investigates attitude transition maneuvers of a gyrosat-satellite between relative equilibria. The primary challenge in transitioning between relative equilibria is the proper adjustment of the system angular momentum so that upon completing the transition maneuver the gyrostat-satellite will satisfy all the requirements for a relative equilibrium. The system angular momentum is a function of the attitude trajectory taken during the transition maneuver. A new concept, the constant orbital momentum equilibrium trajectory or COMET, is introduced as a means to a straight-forward solution to a subset of the possible transitions between relative equilbria. COMETs are a class of paths in SO(3) that a gyrostat-satellite may travel along that maintain a constant system angular momentum. The primary contributions of this dissertation are the introduction and analysis of COMETs and their application to the problem of transitioning a gyrostat-satellite between two relative equilibria. The current work introduces, defines, and analyzes COMETs in detail. The requirements for a path in SO(3) to be a COMET are defined. It is shown via example that COMETs are closed-curves in SO(3). Visualizations of families of COMETs are presented and discussed in detail. A subset of COMETs are shown to contain critical points that represent isolated relative equilibrium attitudes or furcations of the COMET. The problem of transitioning between two relative equilibria is split into the sub-problems of transitioning between relative equilibria on the same COMET and transitioning between relative equilibria on different COMETs. For transitions between relative equilibria on the same COMET, an open-loop control law is developed that drives a gyrostat-satellite along the COMET until the target relative equilibrium is reached. For transitions between relative equilibria on different COMETs, an open-loop control law is developed that transfers a gyrostat-satellite from the initial relative equilibrium to a relative equilibrium that resides on the same COMET as the target relative equilbrium. Acquisition of the target relative equilibrium is then accomplished via the application of the open-loop control law for transitions between relative equilibria on the same COMET. The results of numeric simulations of gyrostat-satellites executing these transitions are presented. / Ph. D.

During January 1986 - September 1988 I studied the behavioral and demographic responses of mule deer (Odocoileus hemionus) to military activity on the Pinon Canyon Maneuver Site in southeastern Colorado. Military training was initiated on the site during August 1985 and recurred approximately 3 times yearly for periods of a month. During a maneuver, 3/7 of the site was used for training in accordance with a rotational land use schedule. I radio-collared fifty adult deer and 49 fawns. Female seasonal home ranges were larger in maneuver than non maneuver areas. During the nonsummer period female home ranges were larger in previous-maneuver than non maneuver areas. Fawn summer home ranges were larger in maneuver than previous-maneuver areas. Male home range sizes differed only for 50% harmonic mean transformation annual home ranges; bucks in maneuver areas had larger home ranges than in non maneuver areas. Female deer in maneuver areas exhibited significant home area shifts between pre maneuver and maneuver periods more frequently (40%) than did deer in non maneuver (control) areas (12.5%). Mule deer in military training areas may have responded to human harassment, alteration of security cover, or destruction of the forage base. I suggest that deer may exhibit a more negative response to unpredictable than predictable disturbances. Demographic data were compared to previous baseline data (1983-1984). Buck annual survival rates did not differ during 1983-1988; doe annual survival rates also were similar during this period. Summer fawn survival differed only between 1984 and 1987, being higher in 1987. All fawn mortalities either were caused or scavenged by coyotes (Canis latrans). Pregnancy rates and fawn production ranged from 88-96% and 1.4-1.7 fawns/doe, respectively. Also, fawn:doe ratios were similar during 1983-1988. Although population estimates increased between 1984 and early 1988, the population declined during late 1888. Two important confounding factors existed on the site during 1983-1988 which make it difficult to assess the effect of military activity on mule deer demographics. First, extensive cattle grazing occurred prior to acquisition of the site and continued through most of the baseline study. Secondly, coyote control was conducted during 1987-1988. These factors may have allowed the deer population to perform better under disturbance conditions. Aerial quadrat sampling was preferred over line transect sampling for censusing mule deer in low density pinyon-juniper (Pinus edulis-Juniperus monosperma) habitat. Management recommendations included training restrictions during fawning season and in severe winters, as well as revegetating disturbed areas. / Master of Science

This thesis proposes a general approach to solve the offline flight-maneuver identification problem using machine learning methods. The purpose of the study was to provide means for the aircraft professionals at the flight test and verification department of Saab Aeronautics to automate the procedure of analyzing flight test data. The suggested approach succeeded in generating binary classifiers and multiclass classifiers that identified six flight maneuvers of different complexity from real flight test data. The binary classifiers solved the problem of identifying one maneuver from flight test data at a time, while the multiclass classifiers solved the problem of identifying several maneuvers from flight test data simultaneously. To achieve these results, the difficulties that this time series classification problem entailed were simplified by using different strategies. One strategy was to develop a maneuver extraction algorithm that used handcrafted rules. Another strategy was to represent the time series data by statistical measures. There was also an issue of an imbalanced dataset, where one class far outweighed others in number of samples. This was solved by using a modified oversampling method on the dataset that was used for training. Logistic Regression, Support Vector Machines with both linear and nonlinear kernels, and Artifical Neural Networks were explored, where the hyperparameters for each machine learning algorithm were chosen during model estimation by 4-fold cross-validation and solving an optimization problem based on important performance metrics. A feature selection algorithm was also used during model estimation to evaluate how the performance changes depending on how many features were used. The machine learning models were then evaluated on test data consisting of 24 flight tests. The results given by the test data set showed that the simplifications done were reasonable, but the maneuver extraction algorithm could sometimes fail. Some maneuvers were easier to identify than others and the linear machine learning models resulted in a poor fit to the more complex classes. In conclusion, both binary classifiers and multiclass classifiers could be used to solve the flight maneuver identification problem, and solving a hyperparameter optimization problem boosted the performance of the finalized models. Nonlinear classifiers performed the best on average across all explored maneuvers.

“Thank God It’s Only Maneuvers!:” Tennessee and the Road to War offers the reader a comprehensive explanation of the importance of the Tennessee Maneuvers of June 1941 to American preparation for World War II. Beginning with pre-war changes in the infantry, followed by the inception of the Armored Force, and continuing through the testing of both during the 1941 Maneuvers, the reader will gain an appreciation of the significance of these actions to overall American preparation before and during the Second World War. This work also presents a look at how these extensive combat actions influenced the people of the State of Tennessee throughout their existence.

This thesis addresses the orbit transfer optimization problem of a spacecraft. The optimal orbit transfer is the process of altering the orbit of a spacecraft with minimum propellant consumption. The spacecrafts are needed to realize orbit transfer to reach, change or keep its orbit. The spacecraft may be a satellite or the last stage of a launch vehicle that is operated at the exo-atmospheric region. In this study, a genetic algorithm based orbit transfer method has been developed. The applicability of genetic algorithm based orbit transfer method has been verified using orbit transfers which are optimal at specific cases. The solution to orbit transfer problem is also searched using steepest descent algorithm.While genetic algorithm can reach the optimal solution, steepest descent algorithm can reach optimal solution when a good initial prediction is provided. The effects of the initial orbital values on the orbit transfer solutions are also studied.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-03-31T15:37:57Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertacao Julierme Araujo _ Versão Final_Biblioteca Central.pdf: 5689636 bytes, checksum: 17f1c9468e867914d378e2fef1626269 (MD5) / Made available in DSpace on 2016-03-31T15:37:57Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertacao Julierme Araujo _ Versão Final_Biblioteca Central.pdf: 5689636 bytes, checksum: 17f1c9468e867914d378e2fef1626269 (MD5) Previous issue date: 2014-09-12 / Vários fatores interligados ou isolados podem desencadear graves anormalidades no Sistema Elétrico de Potência (SEP). Dentre estes fatores, um de fundamental importância é o humano. Os operadores (OP) são aqueles que estão constantemente em contato com os equipamentos das instalações (presencialmente ou remotamente) e desempenham papel vital na correta operação do SEP. Um das principais atividades do OP é a execução de manobras em tempo real, seguindo o estabelecido pelo documento de plano de manobras (PM). No entanto, devido à natureza repetitiva destas atividades os OPs estão sujeitos a cometerem falhas operacionais. Tais eventos podem ocorrer através de uma mera desatenção na execução dos PMs ou na total negligência destes. Operações em equipamentos a partir de manobras mal elaboradas, bem como softwares que não favoreçam a elaboração e a validação de tais manobras, também são fatores que promovem a ocorrência de falhas humanas e anormalidades no processo. Neste trabalho é apresentada uma arquitetura para implementação de um conceito de sistema baseado em software, hardware e sensibilidade a contexto. Em simulações referentes às operações sobre manobras, foi possível observar o sistema atuando de forma preventiva ao alertar o usuário sobre possíveis atividades inconsistentes. A execução de manobras em subestações ocorreu através de uma versão do sistema para dispositivos móveis. Essa abordagem promoveu vários benefícios como, por exemplo, a eliminação de falhas oriundas de atividades repetitivas, o estabelecimento de um mecanismo de confirmação da execução da manobra e o aperfeiçoamento do processo de interação entre os operadores de sistemas e operadores de subestações. Tendo como referência resultados que apontam uma redução de 47% da taxa de anormalidades geradas pelos processos de elaboração e validação de manobras operativas, chegou-se a conclusão que o conceito de sistema apresentado neste trabalho promoveu uma considerável diminuição nas deficiências oriundas desses processos e aumentou a qualidade e a segurança no processo de execução de manobras. / Several factors, interconnected or isolated, may be the cause of abnormalities on the Electric Power Systems (EPS). Among such factors, human factors play a fundamental role. Operators (OPs) are the staff responsible to deal with installations equipment, operated both presently or remotely, playing a vital part to the correct operation of the EPS. One of OP’s main activities is executing maneuvers in real time, following what was established by the maneuvers plan (MP) establishes. However, due to the repetitive nature of these activities, OPs are subject to commit operational failures. These events may occur through a mere inattention in the execution of the MPs or in their total neglect. Equipment operations from poorly elaborated maneuvers, as well as softwares that do not favor the elaboration and validation of those maneuvers are also factors that promote the occurrence of human failure and abnormalities in the process. Herein this work we present a hardware - software architecture sensible to context. In simulations related to operations on maneuvers it was possible to observe the system’s prototype acting preventively when it alerts the user about possible inconsistent activities. The maneuvering in substations occurred through a system version for mobile devices. This approach promoted several benefits such as the correction of the faults originated from repetitive activities, the establishment of a mechanism for confirmation of the maneuvering and the improvement of the interaction process between system and substation operators. Having as reference results which show a reduction of 47% in the rate of abnormalities generated by the drafting and validation of operational maneuvers, we concluded that the concept of system presented in this paper promoted a considerable decrease in deficiencies originated from these processes and increased the quality and safety maneuvers in the process.

This thesis deals with designing a model for simulation and visualisation of air combat tactics. It introduces air combat environment and describes a process for its modeling. Thesis describes basics of air combat, its principles and importance of chosen tactics. Using Jason programming language, artificial agents are created and chosen tactics are implemented. The process of implementing tacitcs is described from analysis to final implementation. Finaly, various types of agents are tested in mock combat against each other.

This master’s thesis deals with driving maneuvers at low coefficient of adhesion, especially in winter season. It includes a list of adhesion coefficients on many surfaces, published by various authors. Figures were through the use of statistical methods divided into normal and exceeding. There are described terms having impact on adhesion. For determination of adhesion was used tests like emergency braking, circle test and slalom. The major part contains specification of used vehicles, surfaces, weather conditions, measuring devices and realized tests. In addition to using accelerometer, there was a successful attempt to use timekeeping facilities to determine deceleration of vehicle. Acquired data were processed and compared to another publications.

Beyond Atlas is a Swedish private company with the goal of exploring the solar system with cheap and reliable spacecraft. Part of their maiden mission, Hugin, aims to demonstrate navigation, propulsion, and communication technology on a 3U CubeSat. This thesis aims to investigate the feasibility of using the Enpulsion NANO electric propulsion (EP) system for deep-space applications and how to best demonstrate its capabilities in low-Earth orbit. Literature reviews of scientific papers and software simulations were conducted to gain an understanding of the underlying processes involved in EP in-orbit operations. Analyses were made on orbital maneuvers, momentum unloading, power and thermal restrictions. The results suggest that the EP system's capabilities is mainly limited by the saturation time of the reaction wheels restricting longer duration orbital maneuvers. Orbital maneuvers for demonstrating the capabilities are proposed based on the limitations imposed on the EP system by the rest of the spacecraft. On the basis of the results of this research, it can be concluded that the Enpulsion NANO thruster's operational range can be utilized both as a low thrust efficient main drive and as a high thrust maneuvering thruster for deep-space applications but is limited by the high power consumption and low thrust-to-power ratio.