To see the other types of publications on this topic, follow the link: Observer.
Dissertations / Theses on the topic 'Observer'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Observer.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Tajpour, Azadeh. "The observer effect." Claremont Graduate University, 2010. http://ccdl.libraries.claremont.edu/u?/stc,77.
Full textAbstract:
My work explores the gray area and the shifting border between "us" and "other." It investigates the helplessness and the submissiveness on both sides of this spectrum and one's passivity that makes the "pain of others" inevitable. Moreover, it examines the individual and collective experiences of guilt and complicity in relation to world events. I am interested in the selective and repressed memories of individuals and nations, the reluctance to look and the ability to forget.
2
Pilard, Laurence. "Observer la stabilisation." Paris 11, 2005. http://www.theses.fr/2005PA112337.
Full textAbstract:
Les systèmes répartis ont deux caractéristiques importantes : ils sont non seulement complexes, mais en plus soumis à des défaillances. Ainsi, la vérification et l'étude de la tolérance aux défaillances dans ces systèmes sont deux problématiques majeurs. Dans cette thèse, nous proposons une méthode de vérification par model-checking d'un système réparti fondée sur les ordres partiels. Nous donnons un algorithme de parcours de graphe qui construit un sous-ensemble réduit de l'espace des états d'un système réparti, dans lequel il est possible de vérifier des propriétés stables du système considéré. D'autre part, nous étudions les systèmes auto-stabilisants qui sont des systèmes répartis naturellement tolérants aux défaillances. Un système auto-stabilisant est un système qui, quelque soit son initialisation et donc après une défaillance, finit par se comporter correctement. L'inconvénient d'un tel système est que celui-ci ne peut pas déterminer de lui-même s'il répond à sa spécification. Dans cette thèse, nous proposons un nouveau modèle fondé sur des observateurs, dans lequel un système auto-stabilisant peut connaître cette information. Dans ce modèle, nous prouvons qu'il est possible de construire un observateur déterministe pour n'importe quelle tâche spécifiée sous un démon synchrone et pour une topologie distinguée, dès lors que cette tâche admet une solution auto-stabilisante. Nous introduisons également la notion d'observateur probabiliste et nous prouvons que de tels observateurs permettent d'observer une plus grande classe de systèmes auto-stabilisants que les observateurs déterministes<br>Distributed systems have two main characteristics: they are complex and subject to failures. So, the verification and the study of fault tolerance in such systems are two major issues. In this thesis, we propose a model-checking verification technique for distributed systems. We present and prove an algorithm, based on partial orders, which builds a small subset of the whole set of states of a distributed system. In the reduced generated graph, it is still possible to verify stable properties of the considered system. We then study self-stabilizing systems which are fault tolerant distributed systems. Self-stabilizing systems are systems which, from any initialization, eventually behaves correctly, regarding to their specifications. The drawback of such systems is that they cannot determine whether or not they verify their specifications. In this thesis we propose a new model, in which the system can decide if it verifies its specification by introducing a new abstraction called observer. With this model, we prove that if there exists a synchronous self-stabilizing distributed solution for some problem in a distinguished network, then there exists a synchronous self-stabilizing distributed solution for the same problem in the same network which accept an observer. Finally, we introduce the notion of a probabilistic observer and we prove that such an observer allows to decide for a larger class of self-stabilizing systems than deterministic observers
3
Painter, Gerald L. "Computer simulated missile-target engagement with a Luenberger Observer and a ground observer." Thesis, Monterey, California. Naval Postgraduate School, 1991. http://hdl.handle.net/10945/26424.
Full textAbstract:
Approved for public release; distribution is unlimited.<br>The technique of proportional navigation is applied to a three dimensional missile-target engagement model. A Luenberger observer is developed to reduce the effects of noise or jamming to the missile's seeker head. A ground observer which computes the deviations in target position and velocity and uplinks the deviations to the missile is also evaluated using the Kalman Filter theory to determine the benefits of the additional information provided to the missile
4
Bravi, I. "INTER-OBSERVER AND INTRA-OBSERVER AGREEMENT IN THE ANALYSIS OF OESOPHAGEAL PH-IMPEDANCE TRACINGS." Doctoral thesis, Università degli Studi di Milano, 2013. http://hdl.handle.net/2434/216406.
Full textAbstract:
AIM
Information resulting from oesophageal 24h pH-impedance monitoring (pH-MII) may have important consequences for patients’ management.
Aims of this study were 1) to evaluate agreement for number of reflux episodes and symptom/reflux association indexes in MII-pH tracings analysis between and within three experienced observers working in different European Centers, 2) to evaluate the predictivity of a shorter manual analysis targeted to the two-minutes window periods before each symptomatic episode with regards to the traditional.
MATERIAL AND METHODS
Forty consecutive pH-MII tracings of patients (23 women, median age 55 years) referred for suspected oesophageal (n=24) or extra-oesophageal (n=16) GORD symptoms in two Northern Italian Centers were included (20 tracings/Center). After automatic analysis (MMS, Enschede, The Nederlands), tracings were duplicated and anonymized. Three expert observers blindly performed the traditional manual analysis on the 40 duplicated tracings, erasing or adding reflux episodes according to their judgment based on the Oporto Criteria. The first manual analysis was performed in a sequential order, the second one in a randomly assigned order. Subsequently a short manual analysis was also blindly performed. Values of both symptom association indexes (Symptom Index=S.I. and Symptom Association Probability=S.A.P.) were transformed into binary response (i.e. positive or negative). Inter- and intra-observer agreement was calculated with Cohen’s Coefficient (k) and/or with percentage of agreement.
RESULTS
Inter-observer agreement on acid reflux was excellent between the three observers for both S.I. and S.A.P. (K=1.0; 100%), whereas considering non-acid reflux it was high for S.I. (95%, 92.5% and 95% of concordance for observer 1,2 and 3 respectively) and moderate for S.A.P. (K=0.35; 85% between observer 1 and 2, K=0.36; 82.5% between observer 1 and 3, K=0.23; 87.5% between observer 2 and 3).
Intra-observer agreement on acid reflux was good to excellent for both S.I. (K=0.77; 95% for observer 1 and 2 and K=1.0; 100% for observer 3), and S.A.P. (K=0.80; 95% , K=0.72; 92.5% and K=1.0; 100% for observer 1, 2 and 3 respectively). Intra-observer agreement on non-acid reflux was high for S.I. (97.5%, 95% and 97.5% of concordance for observer 1, 2 and 3 respectively) and moderate for S.A.P. (K=0.48; 85% and K=0.54; 90% for observer 1 and 3 and good for observer 2, K=0.79; 2.5%).
Considering all the three observers the short analysis was predictive of the traditional one for both S.I., 88% and 98% of the tracings for acid and non-acid reflux, respectively and S.A.P., 99% and 97% of the tracings for acid and non-acid reflux, respectively.
CONCLUSIONS
We found a good inter- and intra-observer agreement for symptom/reflux association indexes, especially when considering acid reflux. Moreover we demonstrated that short analysis was highly predictive of the traditional manual analysis, suggesting that the short one could be used in routine clinical practice with considerable savings.
5
Franco, Nicola. "Distributed Observer Analysis and Design." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/19642/.
Full textAbstract:
A Distributed observer design is described for estimating the state of a continuous-time, input free, linear system. This thesis explains how to construct the local estimators, which comprise the observer inputs and outputs, and it is shown which are the requirements to deal with this structure. Every agent senses an output signal from the system and distributes it across a fixed-time network to its neighbors. The information flow increases the capability of each agent to estimate the state of the system and uses collaboration to improve the quality of data. The proposed solution has several positive features compared to recent results in the literature, which include milder assumptions on the network connectivity and the maximum dimension of the state of each observer does not exceed the order of the plant. The conditions are reduced to certain detectability requirements for each cluster of agents in the network, where a cluster is identified as a subset of agents that satisfy specific properties. Instead, the dimension of each observer is reduced to the number of possible observable states of the system, collected by the agent and by the neighbors.
6
Perrot, Laurie. "Observer les coccolithophores de l'espace." Thesis, Brest, 2017. http://www.theses.fr/2017BRES0032/document.
Full textAbstract:
Les coccolithes, dans les cellules ou détachés, des coccolithophores sont de petites plaquettes de calcite diffusant fortement la lumière. Les efflorescences sont donc très visibles de l’espace et sont couramment quantifiées par l’algorithme Calcite de la NASA appliqué aux données des capteurs de la Couleur de l’Eau.Les coccolithes impactent aussi le produit des matières en suspension non-algales de l’ifremer (MES) largement utilisé sur le plateau continental ouest-européen. Bien que développés indépendamment, ces algorithmes sont basés sur des concepts très proches mais l’algorithme Ifremer est plus souple dans sa modélisation et permet d’établir un lien avec les particules autres que les coccolithes telles les remises en suspension ou les agrégats de particules. L'identification des blooms de coccolithophores sur 18 ans, duGolfe de Gascogne jusqu'au sud de l'Irlande, a été établie par une méthode spectrale, permettant de discriminer la fraction de MES correspondant aux coccolithes. Les blooms suivent le talus au printemps avec une progression vers le nord bien reliée à la variabilité saisonnière de la lumière. La variabilité interannuelle observée indique une légère décroissance globale des blooms, avec une année 2014 aux abondances extrêmement faibles sur toute la région.Les données des campagnes PELGAS en mai dans le Golfe de Gascogne ont mis en évidence la forte corrélation entre le produit MES et la turbidité in situ sur les blooms de coccolithophores. Ce paramètre peut être considéré comme un bon proxy pour le suivi des blooms et pour la description de leur structure verticale.Les données hydrologiques in situ montrent une occurrence plus forte des blooms dans un environnement moins stratifié, des températures plus froides et une salinité plus élevée.La sensibilité de la méthode satellite face à la présence réelle de blooms de coccolithophores a pu être évaluée grâce aux observations in situ de campagnes menées dans le Golfe de Gascogne et en Patagonie.Cette sensibilité reste variable car dépendante de nombreux facteurs intrinsèques aux blooms, liés à la proportion coccolithes/coccosphères et à leur composition taxonomique, qui s’est avérée très riche en mai2016 dans le Golfe de Gascogne<br>Coccoliths, in cells or detached, from coccolithophores are calcite plates with highly backscattering signal.Coccolithophore blooms are visible from space and are currently quantified by Calcite algorithm fromNASA applied to Ocean Color data. Coccoliths impact also the Suspended Particulate Matters (SPM) product from Ifremer, well established in the Northwest european continental shelf. Although these algorithms are independent, they are based on the same basic concepts, but Ifremer algorithm is more adaptable and allows to link up with other particles than coccoliths, as the resuspended matters or aggregates.Coccolithophore blooms identification over 18 years, from bay of Biscay to South Irelands has been established by a spectral method, allowing to discriminate coccoliths from SPM. Blooms follow the continental slope northward in connection with the seasonal variability of irradiance. The interannual variability observed indicates a slight decrease of blooms, with a very poor productive year in 2014.Data from PELGAS cruises in May in the Bay of Biscay highlight the strong correlation between SPM product and the in situ turbidity in coccolithophore blooms.This parameter can be considered a a good proxy for the blooms monitoring and for the description of their vertical structure. Hydrological in situ data show a stronger occurrence in less stratified environment, with lower temperatures and higher salinity.The sensitivity of the satellite to the presence of coccoliths has benn evaluated based on in situ observations from cruises in the Bay of Biscay and in Patagonia. This sensitivity is variable due to a lot of inherent factors, to the coccoliths/coccospheres proportion and to the taxonomic composition which has been rich in May 2016 in the Bay of Biscay
7
Guan, Yingcong. "Implementation of hierarchical observer theory." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq28845.pdf.
Full text
8
McDonough, James P. Strom Mark W. "Forward observer personal computer simulator 2 /." Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2005. http://library.nps.navy.mil/uhtbin/hyperion/05Sep%5FMcDonough.pdf.
Full textAbstract:
Thesis (M.S. in Modeling, Virtual Environment, and Simulation (Movies))--Naval Postgraduate School, September 2005.<br>Thesis Advisor(s): Rudolph P. Darken. Includes bibliographical references (p.65-66). Also available online.
9
Blåberg, Christian. "Chest Observer for Crash Safety Enhancement." Thesis, Linköping University, Department of Electrical Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-12229.
Full textAbstract:
<p>Feedback control of Chest Acceleration or Chest Deflection is believed to be a good way of minimizing the risk of injury. In order to implement such a controller in a car, an observer estimating these responses is needed. The objective of the study was to develop a model of the dummy’s chest capable of estimating the Chest Acceleration and the Chest Deflection during frontal crashes in real time. The used sensor data come from car accelerometer and spindle rotation sensor of the belt, the data has been collected from dummies during crash tests. This study has accomplished the aims using a simple linear model of the chest using masses, springs and dampers. The parameters of the model have been estimated through system identification. Two types of black-box models have also been studied, one ARX model and one state-space model. The models have been tested and validated against data coming from different crash setups. The results show that all of the studied models can be used to estimate the dummy responses, the physical grey-box model and the black-box state-space model in particular.</p><br><p>Genom att använda återkoppling av storheterna bröstacceleration och bröstintryck antas man kunna minska risken för skador vid krockar i personbilar. För att kunna implementera detta behövs en observatör för dessa storheter. Målet med denna studie är att ta fram en modell för att kunna skatta accelerationen i bröstkorgen samt bröstintrycket i realtid i frontala krockar. Sensordata som använts kom från en accelerometer och en givare för att mäta rotationen i bältessnurran. Detta har gjorts genom att modellera bröstkorgen med linjära fjädrar och dämpare. Dess parametrar har skattats från data från krocktester från krockdockor. Två s.k. black-box-modeller har också tagits fram, en ARX-modell och en på tillståndsform. Modellerna har testats och validerats mha data från olika sorters krocktester. Resultaten visar att alla studerade modeller kan användas för att skatta de ovan nämnda storheterna, den fysikaliska modellen och black-box-modellen på tillståndsform fungerade bäst.</p>
10
Rytterstedt, Peter. "Observer for a vehicle longitudinal controller." Thesis, Linköping University, Department of Electrical Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-8820.
Full textAbstract:
<p>The longitudinal controller at DaimlerChrysler AG consists of two cascade controllers. The outer control loop contains the driver assistance functions such as speed limiter, cruise control, etc. The inner control loop consists of a PID-controller and an observer. The task of the observer is to estimate the part of the vehicle's acceleration caused by large disturbances, for example by a changed vehicle mass or the slope of the road.</p><p>As observer the Kalman filter is selected. It is the optimal filter when the process model is linear and the process noise and measurement noise can be modeled as Gaussian noise. In this Master's thesis the theory for the Kalman filter is presented and it is shown how to choose the filter parameters. Simulated annealing is a global optimization technique which can be used when autotuning, i.e., automatically find the optimal parameter settings. To be able to perform autotuning for the longitudinal controller one has to model the environment and driving situations.</p><p>In this Master's thesis it is verified that the parameter choice is a compromise between a fast but jerky, or a slow but smooth estimate. As the output from the Kalman filter is directly added to the control value for the engine and brakes, it is important that the output is smooth. It is shown that the Kalman filter implemented in the test vehicles today can be exchanged with a first-order lag function, without loss in performance. This makes the filter tuning easier, as there is only one parameter to choose.</p><p>Change detection is a method that can be used to detect large changes in the signal, and react accordingly - for example by making the filter faster. A filter using change detection is implemented and simulations show that it is possible to improve the estimate using this method. It is suggested to implement the change detection algorithm in a test vehicle and evaluate it further.</p>
11
Moghrabi, Hana. "The hidden-observer and memory creation." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape15/PQDD_0006/MQ39444.pdf.
Full text
12
Lynch, Alan Francis. "Nonlinear observer synthesis and error linearization." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0016/NQ45691.pdf.
Full text
13
Marini, Bettolo Cecilia. "PoGOLite : The Polarised Gamma-ray Observer." Licentiate thesis, Stockholm : Fysik, Kungliga Tekniska högskolan, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4678.
Full text
14
Babatunde, Patrick O. "Norm-based methods in observer design." Thesis, Brunel University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340841.
Full text
15
Dai, Xuewu. "Observer-based parameterestimation and fault detection." Thesis, University of Manchester, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.504727.
Full textAbstract:
This PhD work is motivated by on-board condition monitoring of gas turbine engines (GTEs) and presents a constructive robust fault detection procedure integrating system identification, time delay compensation, eigenstructure assignment, zero assignment and dynamic observer design techniques, to detect faults in a dynamic system corrupted by disturbances at some frequencies. The main results achieved in this PhD study are: (1) Application of nonlinear least squares to Output Error (OE) model identification. Although OE model shows better performance on long-term prediction, the challenge is the dependency within the long-term prediction errors. The dependency is tackled by an iterative calculation of the gradient, and an approximation of the Hessian matrix is adopted to accelerate the convergence. (2) Delay compensation for high-gain observer based time-varying parameter estimation. In the high-gain observer based parameter estimation, it is usually assumed that the estimation delay is zero. This assumption puts some constraints on the observer design and may not be satisfied in some situations. By examining the transfer function matrices associated with the high-gain observer, a novel time delay calculation and compensation approach is proposed. The main contribution is the proof of the fact that the estimation delay is free from the plant parameter variation. Then a nonlinear phase delay filter approximation technique is used to compensate the delay. (3) Zero assignment in dynamic fault detection observer design. It is well known in filter design that zeros have the ability to block the propagation of some input signal through the system at some frequency. In this thesis. this idea is used to assign zeros to the desired places so that the disturbance can be attenuated. In most observer design research, however, the structure is confined to the classic (static) Luenberger structure where the gain is a constant. numerical matrix. As proved in this thesis, zeros of static observers arc invariant. Hence the dynamic observer is proposed, where a dynamic system (dynamic feedback gain) substitutes for the constant numerical gain matrix. As a result, some additional zeros are introduced and can be assigned arbitrarily to the desired places. To the best of our knowledge, although the concept of zeros in multivariable systems has been proposed by Rosenbrock over thirty years, there have been no known results of utilising zero assignment to robust fault detection observer design.
16
Kirchenkamp, Svenja. "PI-observer techniques applied to mechanical systems." Aachen Shaker, 2010. http://d-nb.info/1000976882/04.
Full text
17
Juhlin-Dannfelt, Peter, and Johan Stridkvist. "Driveline Observer for an Automated Manual Gearbox." Thesis, Linköping University, Department of Electrical Engineering, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-6947.
Full textAbstract:
<p>The Automated Manual Transmission system Opticruise is dependent on signals from sensors located in different parts of the Scania trucks. These signals are of different qualities and have different update frequencies. Some signals and quantities that are hard or impossible to measure are also of importance to this system.</p><p>In this thesis a driveline observer for the purpose of signal improvement is developed and estimations of unknown quantities such as road incline and mass of the vehicle are performed. The outputs of the observer are produced at a rate of 100 Hz, and include in addition to the mass and road incline also the speed of the engine, output shaft of the gearbox, wheel and the torsion in the driveline. Further the use of an accelerometer and the advantages gained from using it in the observer are investigated.</p><p>The outputs show an increased quality and much of the measurement noise is successfully removed without introducing any time delays. A simulation frequency of 100 Hz is possible, but some dependency toward the stiffness of the driveline is found. The observer manages to estimate the road slope accurately. With the use of an accelerometer the road slope estimation is further improved and a quickly converging mass estimation is obtained.</p>
18
Stamnes, Øyvind Nistad. "Adaptive Observer for Bottomhole Pressure During Drilling." Thesis, Norwegian University of Science and Technology, Department of Engineering Cybernetics, 2007. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-8846.
Full textAbstract:
<p>To satisfy the increasing petroleum consumption on a world wide basis there is a need to find new resources. As mature fields are drained, reservoir pressure falls, which again leads to tight pressure margins. To reduce down time due to hole stability problems (e.g. kicks) there is a demand for accurate control of the pressure profile in the well. As the pressure profile is not known and depends on unknown factors such as friction loss there is a need to estimate the pressure. In this thesis an observer that adapts to unknown factors, such as friction and density changes, and estimates the bottomhole pressure is presented. Furthermore, a parameter estimator for the bulk modulus in the annulus is developed as an extension to the observer to facilitate for future control design. Both designs are based on a third order model and provide rigid proofs of stability and convergence of the estimated pressure and parameters. The pressure estimate from the observer is shown to converge to the true pressure under reasonable conditions. For parameter estimates to converge to their true values conditions on excitation are presented. The observer and parameter estimator are tested in simulations and also on log data from a well drilled at the Grane field in the North Sea. Simulation results show that the observer performs very well during typical drilling procedures affecting choke valve opening, pump flows and drill string movements. The observer shows promising behavior when tested on log data from the Grane field.</p>
19
Anisi, David A. "Online trajectory planning and observer based control." Licentiate thesis, Stockholm : Optimization and systems theory, Royal Institute of Technology, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4153.
Full text
20
Villandre, Michael R., and David Brannon. "The forward observer personal computer simulator (FOPCSIM)." Thesis, Monterey, California. Naval Postgraduate School, 2002. http://hdl.handle.net/10945/5409.
Full textAbstract:
Approved for public release; distribution is unlimited.<br>This joint thesis addresses the need for a task trainer for the artillery forward observer task. In recent years, declining budgets, limitations on artillery ammunition and encroachment into training areas have reduced the opportunity to conduct live fire artillery training. Simulation systems available to operating forces utilize technology that is several years out of date and none have a deployable configuration. The goal was to develop a proof of concept simulator that uses advanced 3D graphics to replicate the artillery call for fire task. The system utilizes Digital Terrain Elevation Data (DTED) to produce accurate 3D geometry that is further enhanced by the use of color satellite imagery as a texture overlay to produce extremely realistic terrain. The procedures utilized in the FOPCSIM are taken directly from a cognitive task analysis and executed through keyboard, mouse or voice recognition interfaces. The accuracy of these procedures was validated through a series of studies involving military personnel trained as forward observers. A wide variety of mission types, munitions, targets, training areas and environmental effects are available to the user and may be set at the beginning of the simulation or changed during the simulation through a Graphical User Interface.
21
Li, Qing 1972. "Observer-based fault detection for nuclear reactors." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/30005.
Full textAbstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 2001.<br>Includes bibliographical references (p. 153-156).<br>This is a study of fault detection for nuclear reactor systems. Basic concepts are derived from fundamental theories on system observers. Different types of fault- actuator fault, sensor fault, and system dynamics fault can be detected and localized by studying the asymptotic response of an error signal constructed from the system inputs, system outputs, and observer outputs. False alarm and failure to detect a fault are two decision errors when noise is considered. The goal here is to achieve a reasonable compromise. The two types of decision errors can be characterized by their respective first hitting time of a decision threshold. This in turn is dependent on the design of the observer and the decision rule. Costs corresponding to these two types of decision error are defined by cost functions that are in turn constructed based on experience and knowledge of the system operation. A method has been developed in this research to find an optimal design of the observer, the design of a frequency-dependent output filter, and a decision rule that could achieve the desired economic goals. This technique is applied to nuclear reactor systems and simulations are carried out. The one-group linear nuclear reactor model is used in the observer. The system is modeled by a one-group linear model and by a six-group non-linear model. Results show that this fault detection method can not only detect a fault but also localize it at the same time by constructing specially targeted fault detection filters. These fault detection filters are robust against measurement noise and modeling errors.<br>by Qing Li.<br>Ph.D.
22
Patharlapati, Sai Ram Charan. "Balancing of Network Energy using Observer Approach." Master's thesis, Universitätsbibliothek Chemnitz, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-209453.
Full textAbstract:
Efficient energy use is primarily for any sensor networks to function for a longer time period. There have been many efficient schemes with various progress levels proposed by many researchers. Yet, there still more improvements are needed. This thesis is an attempt to make wireless sensor networks with further efficient on energy usage in the network with respect to rate of delivery of the messages.
In sensor network architecture radio, sensing and actuators have influence over the power consumption in the entire network. While listening as well as transmitting, energy is consumed by the radio. However, if by reducing listening times or by reducing the number of messages transmitting would reduce the energy consumption. But, in real time scenario with critical information sensing network leads to information loss. To overcome this an adaptive routing technique should be considered. So, that it focuses on saving energy in a much more sophisticated way without reducing the performance of the sensing network transmitting and receiving functionalities.
This thesis tackles on parts of the energy efficiency problem in a wireless sensor network and improving delivery rate of messages. To achieve this a routing technique is proposed. In this method, switching between two routing paths are considered and the switching decision taken by the server based on messages delivered comparative previous time intervals. The goal is to get maximum network life time without degrading the number of messages at the server. In this work some conventional routing methods are considered for implementing an approach. This approach is by implementing a shortest path, Gradient based energy routing algorithm and an observer component to control switching between paths. Further, controlled switching done by observer compared to normal initial switch rule. Evaluations are done in a simulation environment and results show improvement in network lifetime in a much more balanced way.
23
Zhao, Songling. "Observer-Based Fault Diagnosis of Wind Turbines." Wright State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=wright1308064070.
Full text
24
Brannon, David A. Villandre Michael R. "The forward observer personal computer simulator (FOPCSIM) /." Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02sep%5FBrannon.pdf.
Full textAbstract:
Thesis (M.S. in Computer Science)--Naval Postgraduate School, September 2002.<br>Thesis advisor(s): Rudolph Darken, Joseph Sullivan. Includes bibliographical references (p. 111-113). Also available online.
25
Eroglu, Mehmet Ali. "Observer based control of an magnetorheological damper." Thesis, University of Sheffield, 2013. http://etheses.whiterose.ac.uk/4520/.
Full textAbstract:
Magnetorheological (MR) fluids enable the rapid and continuous alteration of flow resistance via the application of a magnetic field. This unique characteristic can be utilised to build semi-active dampers for a wide variety of vibration control systems, including structural, automotive, and bridge applications. However, the non-linear behaviour of smart fluid dampers makes the objective of achieving a desired control force very difficult. Most of the control algorithms proposed to overcome this problem require the measurement of both the MR damper force and the states of the system, which increases the complexity of the system. In this thesis, this problem is overcome by developing a non-linear observer. A further aim of this thesis is to investigate the effective control techniques for broadband excited observer-based MR vibration systems. Through an extensive series of numerical and experimental investigations, the general single-degree-of-freedom and tuned mass damper problems are presented. In an experimental case study, the hardware-inthe-loop-simulation method is adopted, which provides an excellent means to bridge the gap between theory and practice when the behaviour of a specific component is complex. Here, the vibration absorber with controllable MR damper is physically tested, whilst the remainder of the structure is simulated in real-time. The results demonstrate that the chosen control strategy can provide significant performance benefits when compared to more commonly used strategies and equivalent passive systems.
26
Lenz, Anthony M. "COFFEE: Context Observer For Fast Enthralling Entertainment." DigitalCommons@CalPoly, 2014. https://digitalcommons.calpoly.edu/theses/1244.
Full textAbstract:
Desktops, laptops, smartphones, tablets, and the Kinect, oh my! With so many devices available to the average consumer, the limitations and pitfalls of each interface are becoming more apparent. Swimming in devices, users often have to stop and think about how to interact with each device to accomplish the current tasks at hand. The goal of this thesis is to minimize user cognitive effort in handling multiple devices by creating a context aware hybrid interface. The context aware system will be explored through the hybridization of gesture and touch interfaces using a multi-touch coffee table and the next-generation Microsoft Kinect. Coupling gesture and touch interfaces creates a novel multimodal interface that can leverage the benefits of both gestures and touch. The hybrid interface is able to utilize the more intuitive and dynamic use of gestures, while maintaining the precision of a tactile touch interface. Joining these two interfaces in an intuitive and context aware way will open up a new avenue for design and innovation.
27
Sarkar, Samrat. "Blur adaptation with source and observer methods." Thesis, Queensland University of Technology, 2017. https://eprints.qut.edu.au/103277/1/Samrat_Sarkar_Thesis.pdf.
Full textAbstract:
Blur adaptation is the improvement of visual and perceptual performance with time following viewing of a blurred target. It is possible to generate blurred images with two different methods – source and observer methods. This study compared blur adaption with source and observer methods for combinations of defocus and higher-order aberrations. Participants adapted to a blurred natural scene for 1 minute and performed a visual acuity task with tumbling Es. Negligible blur adaption was noticed for both source and observer methods. A longer adapting period might be necessary to achieve significant improvement in visual acuity following blur adaptation.
28
Schaal, Peter. "Observer-based engine air charge characterisation : rapid, observer-assisted engine air charge characterisation using a dynamic dual-ramp testing method." Thesis, Loughborough University, 2018. https://dspace.lboro.ac.uk/2134/33247.
Full textAbstract:
Characterisation of modern complex powertrains is a time consuming and expensive process. Little effort has been made to improve the efficiency of testing methodologies used to obtain data for this purpose. Steady-state engine testing is still regarded as the golden standard, where approximately 90% of testing time is wasted waiting for the engine to stabilize. Rapid dynamic engine testing, as a replacement for the conventional steady-state method, has the potential to significantly reduce the time required for characterisation. However, even by using state of the art measurement equipment, dynamic engine testing introduces the problem that certain variables are not directly measurable due to the excitation of the system dynamics. Consequently, it is necessary to develop methods that allow the observation of not directly measurable quantities during transient engine testing. Engine testing for the characterisation of the engine air-path is specifically affected by this problem since the air mass flow entering the cylinder is not directly measurable by any sensor during transient operation. This dissertation presents a comprehensive methodology for engine air charge characterisation using dynamic test data. An observer is developed, which allows observation of the actual air mass flow into the engine during transient operation. The observer is integrated into a dual-ramp testing procedure, which allows the elimination of unaccounted dynamic effects by averaging over the resulting hysteresis. A simulation study on a 1-D gas dynamic engine model investigates the accuracy of the developed methodology. The simulation results show a trade-off between time saving and accuracy. Experimental test result confirm a time saving of 95% compared to conventional steady-state testing and at least 65% compared to quasi steady-state testing while maintaining the accuracy and repeatability of conventional steady-state testing.
29
Swartling, Fredrik. "Gas flow observer for Diesel Engines with EGR." Thesis, Linköping University, Department of Electrical Engineering, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2943.
Full textAbstract:
<p>Due to stricter emission legislation, there is a need for more efficient control of diesel engines with exhaust gas recirculation(EGR). In particular, it is important to estimate the air/fuel ratio accurately in transients. Therefore a new engine gas flow model has been developed. This model divides the gas into one part for oxygen and one part for inert gases. Based on this model an observer has been designed to estimate the oxygen concentration in the gas going into the engine, which can be used to calculate the air/fuel ratio. This observer can also be used to estimate the intake manifold pressure. The advantage of estimating the pressure, instead of low pass filtering the noisy signal, is that the observer does not cause time delay.</p>
30
Nøkland, Harald. "Nonlinear Observer Design for GNSS and IMU Integration." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for teknisk kybernetikk, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-13235.
Full textAbstract:
In order to efficiently control an unmanned vehicle, knowledge about the position, velocity and attitude (orientation) is needed. This thesis address this problem, and designs a navigation system for local navigation using low-cost sensors. Two loosely coupled GNSS/IMU integration filters are developed using a direct state estimation approach. The first is a quaternion based multiplicative extended Kalman filter (MEKF). A multiplicative filter differs from the usual EKF in how the attitude is represented, which is done by a quaternion product. The filter avoids the singular covariance matrix caused by the constraint on the quaternion. Two versions of the filter are developed: one using the q-method to get a measurement of the attitude; and one using vector measurements directly. The second is a nonlinear observer, termed HuaMahony. It is derived by combining two nonlinear algorithms proposed by Mahony et al. and Hua. The resulting nonlinear observer is able to estimate the linear acceleration as well as gyro bias. The nonlinear observer is written on an EKF-like discrete-time corrector-predictor formulation.Both the multiplicative extended Kalman filter and the nonlinear observer are tested and verified through simulations and experimental data. Tests are carried out to examine how different disturbances affects the estimates and to compare the performance results. Simulation results shows an average dynamic accuracy of <0.5 deg RMS for the attitude estimates, for both observers. The results from the experimental tests shows an average roll, pitch and yaw accuracy of (0.3 0.3 2.0) and (0.8 0.7 4.4) deg RMS for the MEKF and HuaMahony observer respectively, where it has been assumed that the Xsens MTi-G built-in EKF estimates are the true values. An advantage of the MEKF is quicker convergence from initial errors, while an advantage of the HuaMahony observer is less computational load. Results show that the HuaMahony is three times faster than the MEKF when it comes to execution time.
31
Bogle, Trina Georgette. "Observer reactions to victims : an equity theory approach /." This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-08182009-040330/.
Full text
32
Aarsnes, Ulf Jakob Flø. "Reduced Order Observer Design for Managed Pressure Drilling." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for teknisk kybernetikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-20951.
Full text
33
Matherly, James Edward III. "Observer interpretation of signaling in consumer decision making." Thesis, University of Maryland, College Park, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=3587355.
Full textAbstract:
<p> This dissertation includes two essays exploring the effects of observers' interpretation of signaling behavior by others on the inferences and decision making of the observers. The first essay investigates how observers make inferences about other people's brand attachment. We propose that observers use the proximity of branded objects to the physical being of the user and the costs incurred to acquire the object to determine the degree of self-extension of the object—that is, to what extent it represents a part of the person's self-concept. Through two studies, we show that to the extent that an object is seen as self-extensive, the user would be inferred to be engaging in self-expression, attempting to convey aspects of their personality to others by using the object. These beliefs about self-expression then lead observers to infer that the individual is attached to the brand. </p><p> In the second essay, we consider how a brand's advertising appeals should be affected by its market position. Building on an experimental study, we present a duopoly model of brand advertising copy decisions, where consumer motives are influenced by Quality-based and Image-based advertising appeals. We show that each brand's decision to select one type of advertising appeal over the other is a function of its market position. We find that larger brands will use Quality-based appeals while smaller brand will use Image-based appeals. We empirically test these findings by examining advertising decisions for major brands found in a popular newsmagazine. Consistent with the model, we find that larger market share brands use Quality-based advertising appeals to a greater extent, while smaller brands use more Image-based appeals. Further, we find that brands that deviate from the predictions of the model are less profitable. Our results suggest that marketing managers should consider their position in the market when crafting advertising appeals, with larger brands emphasizing product quality in their appeals and smaller brands emphasizing the fit of their products with consumers' self-image.</p>
34
Larnder, Chris. "Observer problems in multifractals : the example of rain." Thesis, McGill University, 1995. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=22752.
Full textAbstract:
Non-linear phenomena exhibit extreme variability over a wide range of scales and intensities. In multifractal processes, variability increases algebraically with resolution: as we approach the small scale limit, we develop a highly singular field of diverging and vanishing densities. Even over a finite range of scales, the variability can readily exceed the finite signal-response range capabilities of measuring devices. In face of such extreme behavior, one can no longer consider the problems of observing such processes as "merely" experimental ones.<br>Detectors will rarely be capable of handling the full dynamic range of intensities, missing either the extreme events or the small input signal. Therefore it is of fundamental importance to understand what multifractals "look like" when observed through a detector having only a finite dynamic range.<br>Limitations on the observable dynamic range affect intensities at nearby scales, breaking the scale invariance and imposing a limit on the range of scales over which scaling behaviour can be observed.<br>A simple model of a threshold-type problem, in which a detector has a (finite) minimum detectable signal level, is solved in the multifractal framework. Results include a breaking of the scaling symmetry for scales particularly close to the scale corresponding to the resolution of the detector. The scaling improves as we as we degrade further to lower resolutions. It also improves as we move to higher moment statistics.<br>Rainfall time series from time scales of 180 years to 5 minutes are analysed, revealing, in particular, a break in the spectral scaling behavior near 2.4 hours. Some of the theoretical results are used to show that this break is likely to be caused by instrumental problems at low signal intensities. The correct scaling behavior is successfully recovered from the low resolution information.
35
Pearson, D. W. "Robust observer design and application to gas networks." Thesis, Coventry University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380696.
Full text
36
Aronson, Sara. "Actor observer bias : Påverkar könet hur vi attribuerar?" Thesis, Mälardalens högskola, Akademin för hälsa, vård och välfärd, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-25757.
Full textAbstract:
Actor-observer bias är benägenheten för människor att attribuera sitt eget beteende utifrån omständigheter och andras beteende utifrån deras person. Vi tenderar dessutom att favorisera och vara mer förlåtande i attributionerna till de som tillhör vår ingrupp. Studiens syfte var att undersöka huruvida graden av tillhörighet till ingruppen, kön, påverkar hur vi attribuerar. Studien genomfördes med 102 deltagare, 51 kvinnor och 51 män. En konfliktsituation mellan ett par presenterades för deltagarna där den ena parten i förhållandet (X) beter sig illa mot den andra. Enkäten förekom i tre versioner med X som kvinna, man eller deltagaren själv. Det predicerades bl a att deltagare som upplever hög identifiering med sin ingrupp kommer attribuera övervägande externt då X hör till dennes ingrupp. Resultatet visade inget signifikant stöd för denna hypotes. Tendenser för att kvinnans beteende bedömdes hårdare kunde dock urskiljas. Betydelsen av detta, den eventuella inverkan av könsroller samt framtida forskning diskuteras.
37
Sun, Xiaoyu. "Unknown input observer approaches to robust fault diagnosis." Thesis, University of Hull, 2013. http://hydra.hull.ac.uk/resources/hull:8021.
Full textAbstract:
This thesis focuses on the development of the model-based fault detection and isolation /fault detection and diagnosis (FDI/FDD) techniques using the unknown input observer (UIO) methodology. Using the UI de-coupling philosophy to tackle the robustness issue, a set of novel fault estimation (FE)-oriented UIO approaches are developed based on the classical residual generation-oriented UIO approach considering the time derivative characteristics of various faults. The main developments proposed are: - Implement the residual-based UIO design on a high fidelity commercial aircraft benchmark model to detect and isolate the elevator sensor runaway fault. The FDI design performance is validated using a functional engineering simulation (FES) system environment provided through the activity of an EU FP7 project Advanced Fault Diagnosis for Safer Flight Guidance and Control (ADDSAFE). - Propose a linear time-invariant (LTI) model-based robust fast adaptive fault estimator (RFAFE) with UI de-coupling to estimate the aircraft elevator oscillatory faults considered as actuator faults. - Propose a UI-proportional integral observer (UI-PIO) to estimate actuator multiplicative faults based on an LTI model with UI de-coupling and with added H∞ optimisation to reduce the effects of the sensor noise. This is applied to an example on a hydraulic leakage fault (multiplicative fault) in a wind turbine pitch actuator system, assuming that thefirst derivative of the fault is zero. - Develop an UI–proportional multiple integral observer (UI-PMIO) to estimate the system states and faults simultaneously with the UI acting on the system states. The UI-PMIO leads to a relaxed condition of requiring that the first time derivative of the fault is zero instead of requiring that the finite time fault derivative is zero or bounded. - Propose a novel actuator fault and state estimation methodology, the UI–proportional multiple integral and derivative observer (UI-PMIDO), inspired by both of the RFAFE and UI-PMIO designs. This leads to an observer with the comprehensive feature of estimating faults with bounded finite time derivatives and ensuring fast FE tracking response. - Extend the UI-PMIDO theory based on LTI modelling to a linear parameter varying (LPV) model approach for FE design. A nonlinear two-link manipulator example is used to illustrate the power of this method.
38
Ascencio, Pedro. "Adaptive observer design for parabolic partial differential equations." Thesis, Imperial College London, 2017. http://hdl.handle.net/10044/1/49454.
Full textAbstract:
This thesis addresses the observer design problem, for a class of linear one-dimensional parabolic Partial Differential Equations, considering the simultaneous estimation of states and parameters from boundary measurements. The design is based on the Backstepping methodology for Partial Differential Equations and extends its central idea, the Volterra transformation, to compensate for the parameters uncertainties. The design steps seek to reject time-varying parameter uncertainties setting forth a type of differential boundary value problems (Kernel-PDE/ODEs) to accomplish its objective, the solution of which is computed at every fixed sampling time and constitutes the observer gains for states and parameters. The design does not include any pre-transformation to some canonical form and/or a finite-dimensional formulation, and performs a direct parameter estimation from the original model. The observer design problem considers two cases of parameter uncertainty, at the boundary: control gain coefficient, and in-domain: diffusivity and reactivity parameters, respectively. For a Luenberger-type observer structure, the problems associated to one and two points of measurement at the boundary are studied through the application of an intuitive modification of the Volterra-type and Fredholm-type transformations. The resulting Kernel-PDE/ODEs are addressed by means of a novel methodology based on polynomial optimization and Sum-of-Squares decomposition. This approach allows recasting these coupled differential equations as convex optimization problems readily implementable resorting to semidefinite programming, with no restrictions to the spectral characteristics of some integral operators or system's coefficients. Additionally, for polynomials Kernels, uniqueness and invertibility of the Fredholm-type transformation are proved in the space of real analytic and continuous functions. The direct and inverse Kernels are approximated as the optimal polynomial solution of a Sum-of-Squares and Moment problem with theoretically arbitrary precision. Numerical simulations illustrate the effectiveness and potentialities of the methodology proposed to manage a variety of problems with different structures and objectives.
39
Bogle, Trina G. "Observer reactions to victims: an equity theory approach." Thesis, Virginia Tech, 1991. http://hdl.handle.net/10919/44273.
Full textAbstract:
Among the many problems that victims may face in the aftermath of victimization, a commonly noted yet infrequently studied phenomenon is that of victim disregard. Victims are often ignored by the people they would normally look to for assistance. It was proposed that equity theory might provide a useful framework for understanding this phenomenon. Equity theory suggests victims are ignored because helping is sometimes equity based rather than victim-need based. According to equity theory, learning of victimization threatens an observer's sense of equity. Helping (in the present case,
compensation) is only one way of reducing inequity; if other methods of inequity reduction are used (in this case, perpetrator punishment), equity may be restored without the
victim being assisted. In five studies, victim compensation (the dependent variable) was hypothesized to vary as a function of perpetrator punishment.<br>Master of Science
40
Strom, Mark W. "The Forward Observer Personal Computer Simulator (FOPCSim) 2." Thesis, Monterey, California. Naval Postgraduate School, 2005. http://hdl.handle.net/10945/1970.
Full textAbstract:
Due to declining budgets and decreases in ammunition allowances, the opportunity to conduct live fire artillery training has been greatly reduced. The available simulation trainers are either outdated, require specialize contractor support, or are not deployable. FOPCSim was developed at no cost, is freely available, takes advantages of modern 3D graphics, eliminates costly contractor support, and will run on laptops in support of deploying units. The simulator provides users with real-time performance feedback based on the Marine Corps Training and Readiness standards and was designed according to a cognitive task analysis of the call for fire procedures. To evaluate how well FOPCSim trains the call for fire procedures, an experiment was conducted at The Basic School in Quantico, Virginia. FOPCSim was used in place of the current simulation: Training Set, Fire Observation (TSFO) to evaluate its training effectiveness. By eliminating the overhead associated with most simulators, FOPCSim allows users to perform the call for fire procedures with a high degree of repetitiveness which is needed to train this type of task.
41
Mpungose, Sandile Khayalethu Derrick. "Complete denture occlusion: intra and inter observer analysis." Thesis, University of Western Cape, 2014. http://hdl.handle.net/11394/3352.
Full textAbstract:
Magister Scientiae Dentium - MSc(Dent)<br>Aim: The aim of this study was to investigate the accuracy, intra- and inter-observer
reliability of identifying occlusal markings made by articulating paper on complete
dentures intra-orally. Methods: A series of photographs of 14 tissue borne complete dentures with occlusal markings was obtained. Articulating paper was used intra-orally at the delivery visit to make the occlusal markings. The denture sets were divided into two groups. Group 1 comprised pictures of the 14 complete lower dentures on their own, and group 2 comprised pictures of the same 14 lower dentures together with their opposing upper denture. The two groups of images were loaded into a Microsoft PowerPoint presentation as well as Keynote. Two experienced observers analysed the complete dentures independently and noted the number and distribution of the markings that they felt required adjustment. They differed, but discussed these and reached consensus. These data served as the control. Three groups of observers (10 per group) were then asked to analyse the occlusal markings of the 2 groups of denture images twice, with a two-week interval between each assessment. Before each subsequent assessment, the images were randomised by means of computer-generated random number sequence. The mean number of markings was established for each group and compared with the control mean. Intra-rater reliability was established by comparing the difference of the means of sequential observations for each rater by establishing the z-value. Inter-rater reliability within each group was established
by means of analysis of variance. Results: Considering all the data, in only 17 instances (of the possible 60), did observers’ mean scores not differ from the control mean scores with good intra-rater reliability. In all other 43 instances the observers’ mean scores differed from the control mean scores and/or displayed poor intra-rater reliability. Considerable variation in inter-rater reliability was also found within every group of observers. Conclusion: The results indicate that observers are generally unable to reliably identify occlusal markings warranting occlusal adjustment, made by articulating paper on a lower complete denture. Clinical significance: Articulating paper should not be used intra-orally when delivering removable complete dentures.
42
Salami, Ibrahim al. "Observer based fault detection in networked control systems." Düsseldorf VDI-Verl, 2008. http://d-nb.info/990321029/04.
Full text
43
Melvin, James E. "AUV fault detection using model based observer residuals." Thesis, Monterey, Calif. : Naval Postgraduate School, 1998. http://bosun.nps.edu/uhtbin/hyperion-image.exe/NPS-ME-98-004.pdf.
Full textAbstract:
Thesis (M.S. in Mechanical Engineering and Mechanical Engineer) Naval Postgraduate School, June 1998.<br>Title from cover. Thesis advisor(s): Anthony J. Healey. "June 1998."--Cover. "NPS-ME-98-004"--Cover. Includes bibliographical references (p. 117-118). Also available online.
44
Seward, John F. "A DSP based general self-tuning observer controller /." Online version of thesis, 1993. http://hdl.handle.net/1850/11705.
Full text
45
Cantoni, Elena. "Angiographic systems performance evaluation through a channelized hotelling observer model." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/24837/.
Full textAbstract:
Medical image quality assessment is a challenging subject that depends on measurable and objective physical properties and long time consuming conditions related to the external perception and human subjectivity. To overcome this issue and to include the human observer in the images validation, observer models are typically used. In this thesis work the Channelized Hotelling Observer (CHO) model is used to test three human observer’s ability in terms of performance in signal detection task on large set of fluoroscopic and angiographic images. Three different systems are used to acquire the images: Siemens Artis Q, Philips Azurion 7 C20 and GE Discovery IGS 740. The last two are angiographic machines available in Reggio Emilia’s hospital used to acquire part of the images of the project. The remaining
ones come from an EFOMP’s pre-existing dataset. So, further series of acquisitions are performed on two distinct test objects: TO12 and TO16, that are phantoms appositely realized for contrast-detail (CD) analysis. From CHO application, an α internal noise parameter is estimated and it is used to graph CD curves that are robust tools for evaluating displayed image quality. After a statistical validation of the chosen CD curves, the optimal α are given: in Siemens with TO12, α=3 for fluoroscopy and α=1 for angiography are chosen, in Philips and GE with TO16, phantom limits are achieved in fluoroscopy, in angiography Philips selects α=20 and GE α=10. Comparisons between acquisitions using their optimal CHO CD curves are made and consistent considerations about their statistical significance are done. Indeed, a figure of merit, depending on the contribution of the Kerma Area Product and image quality given by the CD curve, is calculated. The most performant acquisition on Siemens is that with low dose level, FOV=22cm , SID=110cm and pre-filter of 0.6 mm. The best one in angiography between Philips and GE is the low dose level, FOV=32cm, SID=119cm GE acquisition.
46
Wei, Jianfeng. "Observation and Estimation of Nonlinear Systems." Case Western Reserve University School of Graduate Studies / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=case1143611470.
Full text
47
Zhao, Yang. "Path-following Control of Container Ships." Cleveland State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=csu1563275115222067.
Full text
48
Ghatwary, Magdy G. M. el. "Robust fuzzy observer-based fault detection for nonlinear systems." [S.l.] : [s.n.], 2007. http://deposit.ddb.de/cgi-bin/dokserv?idn=985328711.
Full text
49
Yildiz, Ugur. "Multicomponent Batch Distillation Column Simulation And State Observer Design." Master's thesis, METU, 2002. http://etd.lib.metu.edu.tr/upload/12605551/index.pdf.
Full textAbstract:
In the control of batch and continuous distillation columns, one of the most
challenging problem is the difficulty in measuring compositions. This problem
can be handled by estimating the compositions from readily available online
temperature measurements using a state observer. The aim of this
study is to design a state observer that estimates the product composition
in a multicomponent batch distillation column (MBDC) from the temperature
measurements and to test this observer using a batch column simulation. To
achieve this, first a model for MBDC is prepared and compared with the data
from literature where a case column is utilized. After checking the validity of
the simulation package, it is used as a fictitious process for the performance
evaluations.
In the second phase of the study, an extended Kalman Filter (EKF) is designed
by utilizing a simplified model of MBDC and it is implemented for performance
investigation on the case column with 8 trays separating the mixture of cyclohexane,
n-heptane and toluene. The simplified model utilized in EKF results
in response, which have some deviation with rigorous model, mainly due to
the simplification of vapor-liquid equilibrium relationship. In the performance
evaluation, the tuning parameters of EKF<br>the diagonal terms of process noise
covariance matrix and the diagonal terms of measurement model noise covariance
matrix are changed in the range of 50¡<br>1x10¡<br>7 and 0:5¡<br>5x108 and the optimum
values are found as 0:00001 and 5000, respectively. The effect of number of
measurement points is also investigated with a result of number of component
measurements. The effect of measurement period value is also studied and found
that it has a major effect on the performance which has to be determined by the
available computational facilities. The control of the column is done by utilizing
the designed EKF estimator and the estimator is successfully used in controlling
the product purities in MBDC under variable reflux-ratio operation.
50
"The observer and the observed: An ex-fundamentalist speaks." UNION INSTITUTE AND UNIVERSITY, 2008. http://pqdtopen.proquest.com/#viewpdf?dispub=3285234.
Full text