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State Modeling and Pass Automation in Spacecraft ControlKlein, Jim, Kulp, Dan, Rashkin, Bob 10 1900 (has links)
International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / The Integrated Monitoring and Control COTS System (IMACCS) was developed as a proof-of-concept to show that commercial off-the-shelf (COTS) products could be integrated to provide spacecraft ground support faster and cheaper than current practices. A key component of IMACCS is the Altair Mission Control System (AMCS), one of several commercial packages available for satellite command and control. It is distinguished from otherwise similar tools by its implementation of Finite State Modeling as part of its expert system capability. Using the Finite State Modeling and State Transition capabilities of the ALTAIR Mission Control System (AMCS), IMACCS was enhanced to provide automated monitoring, routine pass support, anomaly resolution, and emergency "lights on again" response. Orbit determination and production of typical flight dynamics products, such as acquisition times and vectors, have also been automated.
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Automatic test pattern generation for asynchronous circuitsVasudevan, Dilip Prasad January 2012 (has links)
The testability of integrated circuits becomes worse with transistor dimensions reaching nanometer scales. Testing, the process of ensuring that circuits are fabricated without defects, becomes inevitably part of the design process; a technique called design for test (DFT). Asynchronous circuits have a number of desirable properties making them suitable for the challenges posed by modern technologies, but are severely limited by the unavailability of EDA tools for DFT and automatic test-pattern generation (ATPG). This thesis is motivated towards developing test generation methodologies for asynchronous circuits. In total four methods were developed which are aimed at two different fault models: stuck-at faults at the basic logic gate level and transistor-level faults. The methods were evaluated using a set of benchmark circuits and compared favorably to previously published work. First, ABALLAST is a partial-scan DFT method adapting the well-known BALLAST technique for asynchronous circuits where balanced structures are used to guide the selection of the state-holding elements that will be scanned. The test inputs are automatically provided by a novel test pattern generator, which uses time frame unrolling to deal with the remaining, non-scanned sequential C-elements. The second method, called AGLOB, uses algorithms from strongly-connected components in graph graph theory as a method for finding the optimal position of breaking the loops in the asynchronous circuit and adding scan registers. The corresponding ATPG method converts cyclic circuits into acyclic for which standard tools can provide test patterns. These patterns are then automatically converted for use in the original cyclic circuits. The third method, ASCP, employs a new cycle enumeration method to find the loops present in a circuit. Enumerated cycles are then processed using an efficient set covering heuristic to select the scan elements for the circuit to be tested.Applying these methods to the benchmark circuits shows an improvement in fault coverage compared to previous work, which, for some circuits, was substantial. As no single method consistently outperforms the others in all benchmarks, they are all valuable as a designer’s suite of tools for testing. Moreover, since they are all scan-based, they are compatible and thus can be simultaneously used in different parts of a larger circuit. In the final method, ATRANTE, the main motivation of developing ATPG is supplemented by transistor level test generation. It is developed for asynchronous circuits designed using a State Transition Graph (STG) as their specification. The transistor-level circuit faults are efficiently mapped onto faults that modify the original STG. For each potential STG fault, the ATPG tool provides a sequence of test vectors that expose the difference in behavior to the output ports. The fault coverage obtained was 52-72 % higher than the coverage obtained using the gate level tests. Overall, four different design for test (DFT) methods for automatic test pattern generation (ATPG) for asynchronous circuits at both gate and transistor level were introduced in this thesis. A circuit extraction method for representing the asynchronous circuits at a higher level of abstraction was also implemented. Developing new methods for the test generation of asynchronous circuits in this thesis facilitates the test generation for asynchronous designs using the CAD tools available for testing the synchronous designs. Lessons learned and the research questions raised due to this work will impact the future work to probe the possibilities of developing robust CAD tools for testing the future asynchronous designs.
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Reconfiguration and Recovery of Formation Flying Spacecraft in Eccentric OrbitsRoscoe, Christopher William Thomas 22 September 2009 (has links)
The problem of reference trajectory reconfiguration and long-term uncontrolled recovery of a formation of spacecraft is considered in an eccentric orbit under the influence of the J2 perturbation. Reference trajectories considered are the Projected Circular Orbit, Along-Track Orbit, and their eccentric modifications. Reconfiguration is accomplished using two, finite-pulse thrusts, modeled as impulses. The state transition matrix (STM) is calculated by four methods: (i) analytically from the Hill-Clohessy-Wiltshire equations, (ii) numerical integration using a fourth-order Runge-Kutta method, (iii) from the fundamental matrix of the linearized equations of motion, and (iv) computing the STM for the relative mean orbital elements, the geometric method. Only the geometric method takes into account J2, and it is shown to perform the transfers most accurately of all the methods. The methods are also applied to the reconfiguration maneuvers of the University of Toronto's CanX 4/5 formation flying mission.
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Reconfiguration and Recovery of Formation Flying Spacecraft in Eccentric OrbitsRoscoe, Christopher William Thomas 22 September 2009 (has links)
The problem of reference trajectory reconfiguration and long-term uncontrolled recovery of a formation of spacecraft is considered in an eccentric orbit under the influence of the J2 perturbation. Reference trajectories considered are the Projected Circular Orbit, Along-Track Orbit, and their eccentric modifications. Reconfiguration is accomplished using two, finite-pulse thrusts, modeled as impulses. The state transition matrix (STM) is calculated by four methods: (i) analytically from the Hill-Clohessy-Wiltshire equations, (ii) numerical integration using a fourth-order Runge-Kutta method, (iii) from the fundamental matrix of the linearized equations of motion, and (iv) computing the STM for the relative mean orbital elements, the geometric method. Only the geometric method takes into account J2, and it is shown to perform the transfers most accurately of all the methods. The methods are also applied to the reconfiguration maneuvers of the University of Toronto's CanX 4/5 formation flying mission.
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Theoretical investigation of the eco-evolutionary dynamics of food webs / 食物網の進化生態学的動態に対する理論的研究Takahashi, Daisuke 23 July 2014 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第18497号 / 理博第4012号 / 新制||理||1578(附属図書館) / 31383 / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 山内 淳, 教授 工藤 洋, 教授 田村 実 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM
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Investigation of the regulation of photosynthesis at the molecular level for improvement of plant growth and productivity under limiting light conditions / Investigation of the regulation of photosynthesis at the molecular level for improvement of plant growth and productivity under limiting light conditionsKhuong, Thi thu huong 17 January 2013 (has links)
La lumière est indispensable à la survie des plantes via le processus photosynthétique, pourtant les plantes doivent s'adapter à différentes conditions environnementales où la quantité et la qualité de la lumière peuvent être non optimales pour la photosynthèse. Cela peut provoquer des dégâts photo-induits par formation d'espèces réactives de l'oxygène (ROS), qui sont dangereux pour la plante. Pour limiter la formation des ROS, les plantes mettent en place une régulation importante qui est la dissipation thermique de l'énergie absorbée en excès, appelé Non photochemical quenching (NPQ). Il est connu que la protéine PsbS joue le rôle clé de senseur du pH bas du lumen thylacoïdal, qui est le signal initial pour activer le NPQ. Dans le contexte de cette thèse, on propose d'étudier l'hypothèse que l'absence de la protéine PsbS (diminué NPQ) pourrait augmenter la croissance et la productivité des plantes en conditions contrôlées de faible lumière par l'éminilation de la protéine PsbS chez Arabidopsis thaliana et chez la tomate. Les résultats obtenus indiquent qu'en lumière faible les plantes mutantes montrent une augmentation du rendement de photosystème II conduisant une croissance et un nombre de fleurs significativement augmentés par rapport aux plantes sauvages.De plus, une autre régulation de la photosynthèse, nommée « transitions d'état », est importante pour optimiser la photosynthèse en réponse aux variations de la quantité et de la qualité de la lumière, grâce à la migration réversible des antennes collectrices d'énergie LHCII phosphorylées du PSII au PSI, c'est aussi étudié dans ma thèse. / Light is indispensable for plant survival, but plants have to cope with different environmental situations where light quantity and quality can be not optimal for photosynthesis. This can cause photodamage due to the formation of harmful reactive oxygen species (ROS). To limit ROS formation, plants developed a mechanism important as the dissipation of excess absorbed energy as heat and is called Non Photochemical Quenching (NPQ). The PsbS protein plays the key role of sensor of the low lumenal pH, the signal to activate NPQ. In this thesis, we proposed and investigated the hypothesis that PsbS absence (NPQ decrease) would improve growth under controlled low light upon elimination of the PsbS in Arabidopsis and tomato plants. Results showed that the increase of photosystem II yield in mutant plants leaded to a significant improvement of growth and flower number in mutants as compared with wild type plants under low light, suggesting that this mutation could be useful to improve plant performances in controlled conditions where light is strongly limiting. In addition, another photosynthetic regulation, called “state transitions”, which is important to optimize photosynthesis under variable light for intensity and quality thank to reversible migration of phosphorylated light harvesting complexes LHCII from PSII to PSI also investigated in my thesis.
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Anomaly detection based on multiple streaming sensor dataMenglei, Min January 2019 (has links)
Today, the Internet of Things is widely used in various fields, such as factories, public facilities, and even homes. The use of the Internet of Things involves a large number of sensor devices that collect various types of data in real time, such as machine voltage, current, and temperature. These devices will generate a large amount of streaming sensor data. These data can be used to make the data analysis, which can discover hidden relation such as monitoring operating status of a machine, detecting anomalies and alerting the company in time to avoid significant losses. Therefore, the application of anomaly detection in the field of data mining is very extensive. This paper proposes an anomaly detection method based on multiple streaming sensor data and performs anomaly detection on three data sets which are from the real company. First, this project proposes the state transition detection algorithm, state classification algorithm, and the correlation analysis method based on frequency. Then two algorithms were implemented in Python, and then make the correlation analysis using the results from the system to find some possible meaningful relations which can be used in the anomaly detection. Finally, calculate the accuracy and time complexity of the system, and then evaluated its feasibility and scalability. From the evaluation result, it is concluded that the method
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Analyzing and implementing a third-party state machine library for FriendlyReader and TeCSTHolmstedt, David January 2019 (has links)
FriendlyReader and TeCST are text simplification tools developed at Linköping University, using an API service at the university called SAPIS. Both tools are web services that run in the browser for users. To improve the services an implementation of state-transition tracking was chosen as a way to both improve the website by enabling the user to undo actions, but also enable the client to cache information which lowers the amount of requests required to SAPIS. Two libraries, called MobX and Redux, where compared to find the one which worked best for FriendlyReader and TeCST. The main difference between MobX and Redux is the programming paradigms, MobX is object-oriented while Redux is functional. In the end MobX was chosen due to the object-oriented nature of the library which is more familiar for beginners while also requiring less code to achieve similar results. MobX lacks native support to keep track of previous state transitions which is required to be able to go back to a previous state. Using MobX a new library called GlobalStore was created to solve this problem. An implementation example for synonyms was produced as a proof of concept for FriendlyReader.
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Automatic algorithm for accurate numerical gradient calculation in general and complex spacecraft trajectoriesRestrepo, Ricardo Leon 21 February 2012 (has links)
An automatic algorithm for accurate numerical gradient calculations has been developed. The algorithm is based on both finite differences and Chebyshev interpolation approximations. The novelty of the method is an automated tuning of the step size perturbation required for both methods. This automation guaranties the best possible solution using these approaches without the requirement of user inputs. The algorithm treats the functions as a black box, which makes it extremely useful when general and complex problems are considered. This is the case of spacecraft trajectory design problems and complex optimization systems. An efficient procedure for the automatic implementation is presented. Several examples based on an Earth-Moon free return trajectory are presented to validate and demonstrate the accuracy of the method. A state transition matrix (STM) procedure is developed as a reference for the validation of the method. / text
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Digitally assisted test methodology for RF receiversZeidan, Mohamad A. 25 February 2013 (has links)
Addressing the high cost of RF instrumentation has motivated significant research activity, where researchers have proposed various non-standard and alternative test methods of RF circuits to mitigate high test cost. This dissertation describes a test methodology for RF receivers, whereby simple digital circuits comprise the core of the otherwise complex and costly broadband RF/analog signal generation. The proposed test methodology relies on a digital clock, commonly available to RF ICs for the purpose of digital communication, to generate the broadband RF stimulus needed for the receiver analog tests. The test method also utilizes commonly available baseband signal digitization (on-chip or off-chip) to acquire the baseband signal. It then relies on sophisticated, but inexpensive, signal processing to extract and compute standard RF performance parameters, like gain, noise figure (NF), and input-referred third-order intercept point (IIP3). In addition, the test method can extract important baseband (BB) parameters like the BB filter 3 dB bandwidth (BW), filter rejection at specific BB frequencies, or the BB filter profile. The motivation behind the proposed test methodology can be categorized as both architectural and cost reduction-oriented. Architecturally, the proposed test method aims at shifting the complexity involved in the test of RF receivers from the hardware (input) RF signal generation side to the signal processing done on the (output) baseband side. The process of shifting the complexity from the hardware design side to the signal processing side involves significant complex and sophisticated analysis, which is part of this dissertation. Cost-wise, the proposed test methodology enables the use of digital automatic test equipment (ATE) with limited baseband capability, instead of the full standard RF testers. Such a step reduces the initial tester cost and impacts the cost/sec figure spent on test for the life of the ATE tester, thus leading to test cost reduction. / text
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