Дисертації з теми "Detection and location"
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1
Luo, Anqi, and Lei Ge. "Indoor Location Detection using WLAN." Thesis, KTH, Kommunikationssystem, CoS, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-91200.
Анотація:
The thesis seeks to improve the accuracy of indoor wireless local area network (WLAN) location detection. The main task of the project is the design and analysis of a solution, which utilizes the packets which are already emitted by WLAN devices. The system consists of a signal receiver and signal processing. The positioning system does not transmit, thus the detection is completely passive. The result of measurements on received frames is used to calculate the WLAN transmitter's position. It does not require any transmissions, thus the detection is completely passive. The result of the measurements can be used to calculate the WLAN transmitter’s position. Location systems are more and more viewed as a necessary element of a WLAN system. Positioning accuracy is the most important issue in location system, especial in the indoor WLAN location detection. Indoor location systems are affected by indoor environment both due to multi-path and man-made effects. To resist these problems, we introduce a way to detect the arrival of the first instance of the signal by detecting the signal header. In our experiment, we timestamp the arrival of an IEEE 802.11b header. In our prototype the logic necessary to do this is implemented in an FPGA, specifically that of the Ettus Research USRP. The additional logic is quite small and might easily be added to the receiver in an access point, thus reducing the deployment cost of a location system in a real network. The proposed solution was experimentally verified. From our experiments, the detection works without requiring any changes to the hardware or software of the mobile device. By exploiting existing IEEE 802.11b transmissions the cost and difficulty of deployment is simplified due to the wide usage of IEEE 802.11b in mobile devices. Additionally, the preamble has good correlation properties making it is easy to detect the arrival of a IEEE 802.11frame. Our implementation is based upon open source hardware and software making it possible to implement this solution. A relatively low cost FPGA can be used as the correlation and timestamp circuit is rather simple (in terms of numbers of gates), making this solution feasible for commercial implementation. The method, implementation, testing, and analysis are presented in detail in the thesis.Avhandlingen syftar till att förbättra noggrannheten i inomhus trådlösa lokala nätverk (WLAN) placering upptäckt. Huvuduppgiften för projektet är design och analys av en lösning som utnyttjar paketen som redan avges av WLAN-enheter. Systemet består av en signal mottagare och signalbehandling. Det kräver inga transmissioner, alltså upptäckt är helt passiv. Resultatet av mätningarna kan användas för att beräkna WLAN-sändarens läge. Målet är att förbättra noggrannheten i inomhus plats uppskattning. Läge system alltmer ses som en nödvändig del av WLAN system. Positioneringsnoggrannheten ses som den viktigaste frågan i läge system, speciellt för inomhusbruk WLAN baserade location. Läge system påverkas mer av inomhusmiljöer än utemiljön, eftersom det finns mer multi-path fading och konstgjorda effekter. Att minska dessa problem, vi införa ett sätt att känna av signalen ankomst genom att förbättra upptäckten av ankomsten av IEEE 802.11-huvudet. Detta kan bidra till att besegra multipath effekt och enkla metoden skulle kunna minska kostnaderna för placering i framtiden kopplingspunkter. Den föreslagna lösningen har verifierats experimentellt. Från vårt experiment fungerar upptäckt utan att kräva några ändringar i hårdvara eller mjukvara för den mobila enheten. Genom att utnyttja befintliga IEEE 802.11b sändningar kostnaden och svårigheten att utbyggnaden är förenklad på grund av den breda användningen av IEEE 802.11b i mobila enheter. Dessutom "preamble" har god korrelation egenskaper som gör det lätt att upptäcka ankomsten av en IEEE 802.11-ramen. Vår genomfört bygger på öppen källkod maskin-och programvara som gör det möjligt att genomföra denna lösning. En relativt låg kostnad FPGA kan användas som korrelation och tidstämpel kretsen är ganska enkel (i termer av antalet logikelement), vilket gör denna lösning vara möjlig för kommersiell tillämpning. Metoden, implementation, testning och analys presenteras i detalj i avhandlingen.
2
Pal, Maninder. "Leak detection and location in polyethylene pipes." Thesis, Loughborough University, 2008. https://dspace.lboro.ac.uk/2134/15181.
Анотація:
This thesis is focused on the application of cross-correlation technique for leak detection and location in medium density polyethylene (MDPE) pipes. A leaking water pipe generates noise that depends primarily on water pressure, pipe characteristics and the leak size and shape. This noise, commonly called leak signals, can be used for the purpose of leak detection and leak location in MDPE pipes. A correlation technique is typically employed to detect, position and characterise these water leaks and is proved to be very efficient for metallic pipes. However, the same is not true for MDPE pipes where the attenuation rate with distance of the leak/source signal is very high, and the generated leak signals are of low frequency and narrow bandwidth. In order to locate leak with good accuracy in MDPE pipes, the correlation process relies on the estimation of speed of leak signals in water/pipe and the time delay between leak signals measured at two locations. For time delay estimation, a correlation function is used. Its accuracy depends upon the sharpness of the correlation peak, type and positioning of sensor, and the processing of signals obtained, which in turn further depends upon the characteristics of leak signals. In MDPE pipes, leak signals are of low frequency and narrow bandwidth; however, their frequency response is not well characterised. Therefore, this thesis presents an analytical model to explain the acoustic characteristics of leak signals in MDPE pipes. The model is used to study the effects of the cut-off frequencies of low, high and band pass digital filters and the selection of acoustic/vibration sensors for the correlation technique. It detailed the importance of the cut-off frequency of the high pass filter and the insensitivity of the correlation function to the cut off frequency of the low pass filter.
3
Schoeffel, Hans-Joachim. "Accurate location of subcrustal earthquakes and geodynamic implications." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325571.
4
Lee, Jeong Heon. "Physical Layer Security for Wireless Position Location in the Presence of Location Spoofing." Diss., Virginia Tech, 2011. http://hdl.handle.net/10919/26417.
Анотація:
While significant research effort has been dedicated to wireless position location over the past decades, most location security aspects have been overlooked. Recently, with the proliferation of diverse wireless devices and the desire to determine their position, there is an increasing concern about the security of location information which can be spoofed or disrupted by adversaries or unreliable signal sources. This dissertation addresses the problem of securing a radio location system against location spoofing, specifically the characterization, analysis, detection, and localization of location spoofing attacks by focusing on fundamental location estimation issues.
The objective of this dissertation is four-fold. First, it provides an overview of fundamental security issues for position location, particularly associated with range-based localization. Of particular interest are security risks and vulnerabilities in location estimation, types of localization attacks, and their impact. The second objective is to characterize the effects of signal strength and beamforming attacks on range estimates and the resulting position estimate. The characterization can be generalized to a variety of location spoofing attacks and provides insight into the anomalous behavior of range and location estimators when under attack. Through this effort we can also identify effective attacks that are of particular interest to attack detection and localization. The third objective is to develop an effective technique for attack detection which requires neither prior environmental nor statistical knowledge. This is accomplished by exploiting the bilateral behavior of a hybrid framework using two received signal strength (RSS) based location estimators. We show that the resulting approach is effective at detecting attacks with the detection rate increasing with the severity of the induced location error. The last objective of this dissertation is to develop a localization method resilient to attacks and other adverse effects.
Since the detection and localization approach relies solely on RSS measurements in order to be applicable to a wide range of wireless systems and scenarios, this dissertation focuses on RSS-based position location. Nevertheless, many of the basic concepts and results can be applied to any range-based positioning system.Ph. D.
5
Bonnici, Heidi M. "Automated hippocampal location and extraction." Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/4434.
Анотація:
The hippocampus is a complex brain structure that has been studied extensively and is subject to abnormal structural change in various neuropsychiatric disorders. The highest definition in vivo method of visualizing the anatomy of this structure is structural Magnetic Resonance Imaging (MRI). Gross structure can be assessed by the naked eye inspection of MRI scans but measurement is required to compare scans from individuals within normal ranges, and to assess change over time in individuals. The gold standard of such measurement is manual tracing of the boundaries of the hippocampus on scans. This is known as a Region Of Interest (ROI) approach. ROI is laborious and there are difficulties with test-retest and inter-rater reliability. These difficulties are primarily due to uncertainty in designation of the hippocampus boundary. An improved, less labour intensive and more reliable method is clearly desirable. This thesis describes a fully automated hybrid methodology that is able to first locate and then extract hippocampal volumes from 3D 1.5T MRI T1 brain scans automatically. The hybrid algorithm uses brain atlas mappings and fuzzy inference to locate hippocampal areas and create initial hippocampal boundaries. This initial location is used to seed a deformable manifold algorithm. Rule based deformations are then applied to refine the estimate of the hippocampus locations. Finally, the hippocampus boundaries are corrected through an inference process that assures adherence to an expected hippocampus volume. The ICC values of this methodology when compared to the manual segmentation of the same hippocampi result in a 0.73 for the left and 0.81 for the right hippocampi. These values both fall within the range of reliability testing according to the manual ‘gold standard’ technique. Thus, this thesis describes the development and validation of a genuinely automated approach to hippocampal volume extraction of potential utility in studies of a range of neuropsychiatric disorders and could eventually find clinical applications.
6
Becker, Brian Alan. "Transient fault detection using a watchdog processor." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-11102009-020108/.
7
Li, Miao. "Intelligent power systems: Detection and location of line outages." Thesis, Li, Miao (2014) Intelligent power systems: Detection and location of line outages. Other thesis, Murdoch University, 2014. https://researchrepository.murdoch.edu.au/id/eprint/25670/.
Анотація:
In recent decades, the stability of large power system has attracted much attention. There are many different factors that leading to power system collapse and cause large area blackouts. For example, as demands of consumption grows, the influence of harmonic components and reactive power constraints may cause failure in the power system (Jiao 2011).These factors are usually very difficult to predict in the real world. One of the most important parts of modern power system is the transmission line. With the increased demand for electricity and the scale-up of power networks, the number of long distance transmission lines has increased. They are exposed to different environments such as different weather conditions such as high temperatures or lightning and different terrains such as mountains or canyons. When a line outage happens, it can be very hard to detect the fault’s location and searching and replacing the power line may take quite a long time. This can cause inestimable damage to customers and nations. Even after successfully restoring the power, continuous monitoring of the power system is still needed. Improved monitoring of the power system status could avoid future failure events that could render significant losses to the economy.
The recent method called synchronized phasor measurement allows for real-time monitoring of the entire power system and therefore can be used to detect faults as they occur. Actually, it is the only method that can observe multiple buses in the power system. One such application is the detection of line outages in remote or unobserved parts of the system (Mahoney 2011). A novel algorithm based on DC power flow which can detect line outages effectively will be introduced in this thesis report. Reviewing the concept of DC power flow is an essential part of this report. The simulation softwares used in the report are Power Factory and MATLAB. Finally, the efficiency of the novel algorithm will be assessed. Some suggestions for future works will be presented at the end of this report.
8
Sullivan, Michael R. "Leak detection in gas transmission pipelines." Thesis, Curtin University, 2003. http://hdl.handle.net/20.500.11937/881.
Анотація:
This dissertation applies a commercial flow simulation software package together with common signal processing techniques to the task of accurately detecting leakage in a large commercial gas pipeline. The techniques developed significantly improved the ability to produce accurate, reliable and stable leak detection predictions for the gas transmission pipeline studied and can be applied generally to other pipelines as well. Recommendations for minimum pipeline requirements to implement successful leak detection are also detailed. There are several commercial software packages available that perform some form of leak detection via system modelling. However, due to the commercial aspects of these products, vendors do not publish the detailed methods of leak detection. This thesis identifies the fundamental techniques required to have accurate and reliable leak detection on a gas transmission pipeline, whilst taking into account the lack of measurement data typically encountered on most gas pipelines. The investigation confirmed that a mass balance technique could be successfully used to produce stable leak detection results for compressible flow in gas transmission pipelines. This leak detection [using mass balance] can be achieved without flow measurement along the pipeline, instead, using only pressure and temperature measurements. Although it is recognized that flow measurement data will greatly improve the ability to detect leaks, the focus of this work is on pipelines where this flow measurement data at intermediate points along the pipeline is not available. It was also demonstrated the reliability of the leak detection was improved by the application of on-line signal processing techniques at various stages of the data processing.It was clear early into the investigation that the majority of the errors within the leak detection model were created by random errors from the input field data. These non-systematic errors from the measurement data that included pressure and temperature, produced interference with model output. This interference resembled random “white” noise that was removed by a combination of well established data filtering techniques. The most appropriate process of calculating leak detection flow was determined after analysing the results of different techniques applied to large quantities of actual pipeline operating data. The validation of the on-line techniques developed provides a valuable resource for those wishing to implement similar leak detection schemes elsewhere. Furthermore a software environment was chosen which incorporated an open input and output platform for data that could be interfaced with any operating system. Therefore these techniques can be applied to the numerous Supervisory Control and Data Acquisition (SCADA) systems in operation throughout the gas transmission industry, to provide a low cost solution to leak monitoring.
9
Groh, Brittany Nicole. "Impact of Expressive Intensity and Stimulus Location on Emotion Detection." TopSCHOLAR®, 2017. https://digitalcommons.wku.edu/theses/2020.
Анотація:
Previous research demonstrates that the age of an observer, the peripheral location of a face stimulus on a display, and the intensity of the emotion expressed by the face all play a role in emotion perception. Older individuals have more difficulty identifying emotion in faces, especially at lower expressive intensities. The purpose of the current study was to understand how younger and older adults’ abilities to detect emotion in facial stimuli presented in the periphery would be affected by the intensity of the emotional expressions and the distance that the expressions are presented away from the center of the display. The current study presented facial stimuli for a short duration to bypass reactionary attentional influences. More intense fearful and angry expressions were expected to be easier to classify for both younger and older adults than lower intensity expressions, but all expressions were expected to become more difficult to classify when presented further in the periphery. Older adults and younger adults displayed similar emotion detection for typical and extreme intensity angry expressions and for high intensity fearful expressions. However, older adults struggled to detect typical intensity fear, and this deficit grew with the angle of eccentricity from which the stimuli were presented from the center of the display. Possible explanations for these age differences are discussed.
10
Wang, Haibo, and 王海波. "Fault detection and fault-tolerant control for dynamic systems." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B42576842.
11
Wang, Haibo. "Fault detection and fault-tolerant control for dynamic systems." Click to view the E-thesis via HKUTO, 2002. http://sunzi.lib.hku.hk/hkuto/record/B42576842.
12
Mufti, Muid Ur-Rahman. "Fault detection and identification using fuzzy wavelets." Diss., Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/16472.
13
Loos, Matthieu. "Single phase to ground fault detection and location in compensated network." Doctoral thesis, Universite Libre de Bruxelles, 2013. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209544.
Анотація:
This work takes place in the context of distribution power system protection and tries to improve the detection and location of earth faults. The protection problem is vast and many ideas emerge every year to enhance the reliability of the grid. The author has focused his energy into the compensated and isolated network protection in the specific case of single phase earth fault. This PhD thesis is divided in two main parts that might be considered as independent. The first part studies the detection of single phase earth fault and the second analyzes the fault location of such fault.Pragmatism was asked during these three years because a product development was necessary especially regarding the fault detection problem. The first part of the thesis took 18 months of research and development to obtain a prototype of transient protection able to detect single phase earth fault in compensated and isolated network. The sensitivity of the algorithm has been emphasized regarding the fault impedance and to detect earth fault up to 5 kOhm depending on the network characteristic. The fault location problem has been much more theoretical although the problem links to the accuracy of the algorithm and its robustness regarding wrong fault location indication has been strongly considered.
Compensated networks and in some conditions isolated networks are distribution from 12 kV up to 110 kV mostly used in East and North Europe but also in China. Others areas also work with such networks but they also have others systems and they do not use them on all the territory. These networks have the particularity to obtain very small fault current in case of single phase earth fault. Low current means the difference between a faulty and a sound feeder is not significant. Therefore classic overcurrent protection is completely useless to protect the network, forcing the development of more complex algorithm. A possibility to overcome the problem of the small fault current is to develop a transient protection. The transient occurring at the beginning of the fault has strong information to distinguish a faulty from a sound feeder. In this work I have chosen to use not only the transient but also the steady state to get the best sensitivity.
Then the fault location has been investigated but the small information coming from the faulty feeder is not sufficient to have a precise enough position of the fault. Therefore, active system has been suggested to be implemented in the grid to increase the faulty current and have enough power for a precise location. Different existing algorithms based on the steady state at the nominal frequency are compared using a tool developed during this work. Recommendations are then made depending on the topology, the network parameters, the measurements precision, etc. Due to the complexities of the problem, a simulator has been coded in Matlab .The user of a possible fault location must then use this tool to understand and see the future fault location precision that he could obtain from different algorithm on his network.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished
14
Mehranbod, Nasir Soroush Masoud. "A probabilistic approach for sensor fault detection and identification /." Philadelphia : Drexel University, 2002. http://dspace.library.drexel.edu/handle/1721.1/68.
15
Gené, Mola Jordi. "Fruit detection and 3D location using optical sensors and computer vision." Doctoral thesis, Universitat de Lleida, 2020. http://hdl.handle.net/10803/669110.
Анотація:
Per tal de satisfer les necessitats alimentàries d’una població mundial creixent, és necessari optimitzar la producció agrícola, incrementant la productivitat i la sostenibilitat de les explotacions. Per aconseguir-ho, es preveu que els sistemes automàtics de detecció i localització de fruits seran una eina essencial en la gestió de les plantacions fructícoles, amb aplicacions directes a la predicció de la collita, el mapat de la producció i la recol·lecció automatitzada. Malgrat els avenços aconseguits en àmbits com la robòtica o la visió per computador, la localització 3D de fruits continua essent un repte que ha de fer front a problemes com la identificació de fruits oclosos per altres òrgans vegetatius, o la possibilitat de treballar en diferents condicions d’il·luminació. La present tesi pretén contribuir en el desenvolupament de noves metodologies de detecció i localització de fruits mitjançant la combinació de sensors de base fotònica i d’algoritmes de visió artificial. Per tal de minimitzar els efectes produïts per unes condicions d’il·luminació variable, es proposa l’ús de sensors actius que treballen en l’espectre de llum infraroja. En concret, s’han testejat sensors LiDAR (light detection and ranging) i càmeres de profunditat (RGB-D) basades en el principi de temps de vol (time-of-flight), els quals proporcionen els valors d’intensitat de llum reflectida pels diferents elements mesurats. D’altra banda, per minimitzar el número d’oclusions s’han estudiat dues estratègies: (1) l’aplicació forçada d’aire; (2) la utilització de tècniques d’escaneig des de diferents punts de vista, com ara Structure-from-Motion (SfM). Els resultats obtinguts demostren que les dades d’intensitat proporcionades pels sensors actius LiDAR i RGB-D són de gran utilitat per la detecció de fruits, el que suposa un avanç en l’estat de l’art, ja que aquesta capacitat radiomètrica no havia estat estudiada anteriorment. D’altra banda, les dues estratègies testejades per minimitzar el número de fruits oclosos han demostrat incrementar el percentatge de fruits detectats. De totes les metodologies estudiades, la combinació de xarxes neuronals profundes amb tècniques de SfM és la que presenta més bons resultats, amb percentatges de detecció superiors al 90% i menys d’un 4% de falsos positius.Para satisfacer las necesidades alimentarias de una población mundial creciente, es necesario optimizar la producción agrícola, incrementando la productividad y la sostenibilidad de las explotaciones. Para conseguirlo, se prevé que los sistemas automáticos de detección y localización de frutos serán una herramienta esencial en la gestión de las plantaciones frutícolas, con aplicaciones directas a la predicción de cosecha, al mapeado de la producción y a la recolección automatizada. A pesar de los avances conseguidos en ámbitos como la robótica o la visión artificial, la localización 3D de frutos continua siendo un reto que debe de hacer frente a problemas como la identificación de frutos ocluidos por otros órganos vegetativos, o la posibilidad de trabajar en distintas condiciones de iluminación. La presente tesis pretende contribuir en el desarrollo de nuevas metodologías de detección y localizacion de frutos mediante la combinación de sensores de base fotónica y de algoritmos de visión artificial. A fin de minimizar los efectos producidos por unas condiciones de iluminación variable, se propone el uso de sensores activos que trabajan en espectros de luz infrarroja. En concreto, se han testeado sensores LiDAR (light detection and ranging) y cámaras de profundidad (RGB-D) basadas en el principio de tiempo de vuelo (time-of-flight), los cuales proporcionan valores de intensidad de la luz reflejada por los objetos escaneados. Por otra parte, para minimizar el número de oclusiones se han estudiado dos estrategias: (1) la aplicación forzada de aire; (2) la utilización de técnicas de escaneo desde distintas perspectivas, tales como Structure-from-Motion (SfM). Los resultados obtenidos demuestran que los datos de intensidad proporcionados por los sensores LiDAR y RGB-D son de gran utilidad para la detección de frutos, lo que supone un avance en el estado del arte, ya que esta capacidad radiométrica no había estado estudiada anteriormente. Por otra parte, las dos estrategias testeadas para minimizar el número de oclusiones han demostrado incrementar el porcentaje de detección. De todas las metodologías estudiadas, la combinación de redes neuronales profundas con técnicas de SfM es la que presenta mejores resultados, con porcentajes de detección superiores al 90% y con menos de un 4% de falsos positivos.
To meet the food demands of an increasing world population, farmers are required to optimize agriculture production by increasing crop productivity and sustainability. To do so, fruit detection and 3D location systems are expected to be an essential tool in the agricultural management of fruit orchards, with applications in fruit prediction, yield mapping, and automated harvesting. Despite the latest advances in robotics and computer vision, the development of a reliable system for 3D fruit location remains a pending issue to deal with problems such as the identification of occluded fruits and the variable lighting conditions of agricultural environments. The present thesis aims to contribute to the development of new methodologies for fruit detection and location by combining optical sensors and artificial intelligence algorithms. In order to minimize variable lighting effects, it is proposed the use of active sensors that work in the infrared light spectrum. In particular, light detection and ranging sensors (LiDAR) and depth cameras (RGB-D) based on the time-of-flight principle were evaluated. These sensors provide the amount of backscattered infrared light reflected by the measured objects. With respect to minimizing the number of fruit occlusions, two different approaches were tested: (1) the application of forced air flow; and (2) the use of multi-view scanning techniques, such as structure-from-motion (SfM) photogrammetry. The results have demonstrated the usefulness of the backscattered intensity provided by LiDAR and RGB-D sensors for fruit detection. This supposes an advance in the state-of-the-art, since this feature has not previously been exploited. Both of the strategies tested to minimize fruit occlusions showed an increase in the fruit detection rate. Of all the tested methodologies, the combination of instance segmentation neural networks and SfM photogrammetry gave the best results, reporting detection rates higher than 90% and false positive rates under 4%.
16
Haider, Raja Umair. "Fault Detection in WLAN Location Fingerprinting Systems Using Smartphone Inertial Sensors." Thesis, Linköpings universitet, Kommunikationssystem, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-81940.
Анотація:
Indoor positioning is a rapidly growing research area, enabling new innovative location-aware applications and user-oriented services. Location Fingerprinting (LF) is the positioning technique of coupling a physical location with observed radio signal measurements. In the terms of indoor LF using Wireless Local Area Network (WLAN) it refers to the use of network measurements from the WLAN Access Points (APs) to tag known locations. A data set is created containing reference fingerprints for the area of interest and is known as a radio map. A radio map can later be used to find a user's location in the area of interest. WLAN infrastructures are vulnerable to many kinds of faults and malicious attacks, including, an attacker jamming the signal from an AP, or an AP becoming unavailable during positioning due to power outage. These faults can be collectively characterized as an AP-failure. In LF positioning systems, AP-failure faults can significantly degrade the performance of a LF system due to the difference between the current fingerprints and radio map created with all APs being available. It is desirable to detect such faulty APs, in order to take actions towards fault-mitigation and restoration, in case of a malicious attack. In this work, we have developed a fault detection algorithm that uses inertial sensors (i.e., accelerometer, magnetometer) available in smartphones to detect AP-failure faults in LF systems. Inertial Measurement Unit (IMU) has become an integral part of all high-end smartphones. IMU can be used to infer location information on the smartphone. The main idea is to have two parallel position streams, the LF positioning and the IMU positioning, and to compare the mean positioning error between the two. Since IMU positioning is fairly accurate once provided with starting coordinates, we use it to detect abnormal behaviour in LF positioning system, such as highly erroneous estimates signifying an AP-failure fault present in the system. The performance of the proposed detection algorithm is evaluated with several real-life AP-related faults. The proposed algorithm exhibits low probability of false alarms in the detection of faulty APs. The conclusion is that using IMU based positioning is an effective and robust solution in terms of fault detection in LF systems.
17
Frimpong, George Kwabena. "Acoustic detection and location of partial discharges in power transformer tanks." Diss., Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/15708.
18
Farley, Ben. "Optimal sensor placement for detection and location of leak/burst events." Thesis, University of Sheffield, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.541990.
19
Tan, Qinling Jeanette Olivia. "Passive coherent detection and target location with multiple non-cooperative transmitters." Thesis, Monterey, California: Naval Postgraduate School, 2015. http://hdl.handle.net/10945/45951.
Анотація:
Approved for public release; distribution is unlimitedPassive bistatic radars (PBR) and passive multistatic radars (PMR) use opportunistic transmitters to detect and locate targets. In this thesis, a maritime scenario was modeled with merchant vessels serving as multiple non-cooperative opportunistic transmitters while a frigate warship equipped with Electronic Warfare (EW) and Direction Finding (DF) receivers takes on the role of the receiver in a PBR/PMR configuration. The targets are assumed to be the generic Formidable-class frigate. A MATLAB model is developed to simulate the operating environment and passive detection and location process. Detection coverage is investigated to propose optimal PBR/PMR configurations and geometry, while elliptical and hyperbolic target location methods are explored to quantify the effects of PBR/PMR parameters and geometry on target estimated location uncertainty.
20
Sullivan, Michael R. "Leak detection in gas transmission pipelines." Curtin University of Technology, School of Engineering, 2003. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=15189.
Анотація:
This dissertation applies a commercial flow simulation software package together with common signal processing techniques to the task of accurately detecting leakage in a large commercial gas pipeline. The techniques developed significantly improved the ability to produce accurate, reliable and stable leak detection predictions for the gas transmission pipeline studied and can be applied generally to other pipelines as well. Recommendations for minimum pipeline requirements to implement successful leak detection are also detailed. There are several commercial software packages available that perform some form of leak detection via system modelling. However, due to the commercial aspects of these products, vendors do not publish the detailed methods of leak detection. This thesis identifies the fundamental techniques required to have accurate and reliable leak detection on a gas transmission pipeline, whilst taking into account the lack of measurement data typically encountered on most gas pipelines. The investigation confirmed that a mass balance technique could be successfully used to produce stable leak detection results for compressible flow in gas transmission pipelines. This leak detection [using mass balance] can be achieved without flow measurement along the pipeline, instead, using only pressure and temperature measurements. Although it is recognized that flow measurement data will greatly improve the ability to detect leaks, the focus of this work is on pipelines where this flow measurement data at intermediate points along the pipeline is not available. It was also demonstrated the reliability of the leak detection was improved by the application of on-line signal processing techniques at various stages of the data processing.It was clear early into the investigation that the majority of the errors within the leak detection model were created by random errors from the input field data. These non-systematic errors from the measurement data that included pressure and temperature, produced interference with model output. This interference resembled random “white” noise that was removed by a combination of well established data filtering techniques. The most appropriate process of calculating leak detection flow was determined after analysing the results of different techniques applied to large quantities of actual pipeline operating data. The validation of the on-line techniques developed provides a valuable resource for those wishing to implement similar leak detection schemes elsewhere. Furthermore a software environment was chosen which incorporated an open input and output platform for data that could be interfaced with any operating system. Therefore these techniques can be applied to the numerous Supervisory Control and Data Acquisition (SCADA) systems in operation throughout the gas transmission industry, to provide a low cost solution to leak monitoring.
21
Obaid, Ramzy R. "Detection of rotating mechanical asymmetries in small induction machines." Diss., Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/13527.
22
Fischer, Daniel Poehlman Skipper William. "Artificial intelligence techniques applied to fault detection systems /." *McMaster only, 2004.
23
Wang, Xinheng. "Characterization, detection and location of sheath fault on underground power transmission cables." Thesis, Brunel University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367857.
24
Wang, Hao. "Two-Stage Fault Location Detection Using PMU Voltage Measurements in Transmission Networks." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/54565.
Анотація:
Fault location detection plays a crucial role in power transmission network, especially on security, stabilization and economic aspects. Accurate fault location detection in transmission network helps to speed up the restoration time, therefore, reduce the outage time and improve the system reliability [1]. With the development of Wide Area Measurement System (WAMS) and Phasor Measurement Unit (PMU), various fault location algorithms have been proposed.
The purpose of this work is to determine, modify and test the most appropriate fault location method which can be implemented with a PMU only linear state estimator. The thesis reviews several proposed fault location methods, such as, one-terminal [2], multi-terminal [3]-[11] and travelling wavelets methods [12]-[13]. A Two-stage fault location algorithm using PMU voltage measurements proposed by Q. Jiang [14] is identified as the best option for adaption to operate with a linear state estimator. The algorithm is discussed in details and several case studies are made to evaluate its effectiveness. The algorithm is shown to be easy to implement and adapt for operation with a linear state estimator. It only requires a limited number of PMU measurements, which makes it more practical than other existing methods. The algorithm is adapted and successfully tested on a real linear state estimator monitored high voltage transmission network.Master of Science
25
RezaeiDivkolaei, Pouya. "DETECTION, CLASSIFICATION, AND LOCATION IDENTIFICATION OF TRAFFIC CONGESTION FROM TWITTER STREAM ANALYSIS." OpenSIUC, 2017. https://opensiuc.lib.siu.edu/theses/2257.
Анотація:
Social media today is an important source of information about various events happening around the world. Among various social networking platforms, microtext based ones such as Twitter are of special interest as they are also a rich source of real-time events. In this thesis, our goal is to study the effectiveness of using Twitter as a social sensor for obtaining real-time information on road traffic conditions. Specifically, we focus on: i) identifying tweets that contain traffic event related information, ii) classify such tweets into six main groups of accident, fire, road construction, police activities, weather and others, iii) extract fine-grained location information about the traffic incident by analyzing tweet text. Our experimental results show that using Twitter as a social sensor for obtaining rich information about traffic events is indeed a promising approach. We show that we can correctly detect traffic related tweets with an accuracy of 81%. Moreover, the accuracy of correctly classifying traffic related tweets into one of the six categories is 97%. Lastly, our experimental results show that using only geo-tags of tweets is not sufficient for fine-grained localization of traffic incidents due to two reasons: i) a vast majority of traffic related tweets do not contain geo-tags, and ii) the location mentioned in the tweet text and the geo-tag of a tweet do not always agree. Such observations prove that fine-grained localization of traffic incidents from tweet must also include analysis of the tweet text using Natural Language Processing techniques.
26
Yang, Zaiyue. "Fault detection, estimation and control of periodically excited nonlinear systems." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B40887984.
27
Rittenhouse, Scott A. "Diagnosis of operational changes in microelectromechanical systems via fault detection." Morgantown, W. Va. : [West Virginia University Libraries], 2004. https://etd.wvu.edu/etd/controller.jsp?moduleName=documentdata&jsp%5FetdId=3632.
Анотація:
Thesis (M.S.)--West Virginia University, 2004.Title from document title page. Document formatted into pages; contains v, 141 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 137-141).
28
Khan, Mohammad Ziaullah. "Concurrent detection of transient faults in microprocessors." Diss., Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/54212.
Анотація:
A large number of errors in digital systems are due to the presence of transient faults. This is especially true of microprocessor-based systems working in a radiation environment that experience transient faults due to single event upsets. These upsets cause a temporary change in the state of the system without any permanent damage. Because of their random and non-recurring nature, transient faults are difficult to detect and isolate, hence they become a source of major concern, especially in critical real-time application areas. Concurrent detection of these errors is necessary for real-time operation.
Most existing fault tolerance schemes either use redundancy to mask effects of transient faults or monitor the system for abnormal operations and then perform recovery operation. Although very effective, redundancy schemes incur substantial overhead that makes them unsuitable for small systems. Most monitoring schemes, on the other hand, only detect control flow errors.
A new approach called Concurrent Processor Monitoring for on-line detection of transient faults is proposed that attempts to achieve high error coverage with small error detection latency. The concept of the execution profile of an instruction is defined and is used for detecting control flow and execution errors. To implement this scheme, a watchdog processor is designed for monitoring operation of the main processor. The effectiveness of this technique is demonstrated through computer simulations.Ph. D.
29
Liu, Zhi. "Location Estimation and Geo-Correlated Information Trends." Thesis, University of North Texas, 2017. https://digital.library.unt.edu/ark:/67531/metadc1062799/.
Анотація:
A tremendous amount of information is being shared every day on social media sites such as Facebook, Twitter or Google+. However, only a small portion of users provide their location information, which can be helpful in targeted advertising and many other services. Current methods in location estimation using social relationships consider social friendship as a simple binary relationship. However, social closeness between users and structure of friends have strong implications on geographic distances. In the first task, we introduce new measures to evaluate the social closeness between users and structure of friends. Then we propose models that use them for location estimation. Compared with the models which take the friend relation as a binary feature, social closeness can help identify which friend of a user is more important and friend structure can help to determine significance level of locations, thus improving the accuracy of the location estimation models. A confidence iteration method is further introduced to improve estimation accuracy and overcome the problem of scarce location information. We evaluate our methods on two different datasets, Twitter and Gowalla. The results show that our model can improve the estimation accuracy by 5% - 20% compared with state-of-the-art friend-based models.
In the second task, we also propose a Local Event Discovery and Summarization (LEDS) framework to detect local events from Twitter. Many existing algorithms for event detection focus on larger-scale events and are not sensitive to smaller-scale local events. Most of the local events detected by these methods are major events like important sports, shows, or big natural disasters. In this work, we propose the LEDS framework to detect both bigger and smaller events. LEDS contains three key steps: 1) Detecting possible event related terms by monitoring abnormal distribution in different locations and times; 2) Clustering tweets based on their key terms, time, and location distribution; and 3) Extracting descriptions include time, location, and key sentences of local events from clusters. The model is evaluated on a real-world Twitter dataset with more than 60 million tweets. The analysis of Twitter data can help to predict or explain many real-world phenomena. The relationships among events in the real world can be reflected among the topics on social media. In the third task, we propose the concept of topic association and the associated mining algorithms. Topics with close temporal and spatial relationship may have direct or potential association in the real world. Our goal is to mine such topic associations and show their relationships in different time-region frames. We propose to use the concepts of participation ratio and participation index to measure the closeness among topics and propose a spatiotemporal index to calculate them efficiently. With the topic filtering and the topic combination, we further optimize the mining process and the mining results.
30
Lennox, James. "Multivariate subspaces for fault detection and isolation : with application to the wastewater treatment process /." [St. Lucia, Qld.], 2001. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16704.pdf.
31
Jain, Sharad. "Skidding and fault detection in the bearings of wind-turbine gearboxes." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608104.
32
Sumislawska, M. "Fault detection and diagnosis and unknown input reconstruction based on parity equations concept." Thesis, Coventry University, 2012. http://curve.coventry.ac.uk/open/items/c660a4ab-7312-4bda-8578-6114c9453366/1.
Анотація:
There are two main threads of this thesis, namely, an unknown (unmeasurable) input reconstruction and fault detection and diagnosis. The developed methods are in the form of parity equations, i.e. finite impulse response filters of the available input and output measurements. In the first thread the design of parity equations for the purpose of an unknown input reconstruction of linear, time-invariant, discrete-time, stochastic systems is taken into consideration. An underlying assumption is that both measurable system inputs as well as the outputs can be subjected to noise, which leads to an errors-in-variables framework. The main contribution of the scheme is accommodation of the Lagrange multiplier method in order to minimise the influence of the noise on the unknown input estimate. Two potential applications of the novel input reconstruction method are proposed, which are a control enhancement of a hot strip steel rolling mill and an estimation of a pollutant level in a river. Furthermore, initial research is conducted in the field of the unknown input recon- struction for a class of nonlinear systems, namely, Hammerstein-Wiener systems, where a linear dynamic block is preceded and followed by a static nonlinear function. Many man-made as well as naturally occurring systems can be accurately described using Hammerstein-Wiener models. However, it is considered that not much attention has been paid to Hammerstein-Wiener systems in the errors-in-variables framework and in this thesis it is aimed to narrow this gap. The second thread considers a problem of robust (disturbance decoupled) fault de- tection as well as fault isolation and identification. Unmeasurable external stimuli, parameter variations or discrepancies between the system and the model act as distur- bances, which can obstruct the fault detection process and lead to false alarms. Thus, a fault detection filter needs to be decoupled from the disturbances. In this thesis the right eigenstructure assignment method used for the robust fault detection filter design is extended to systems with unstable invariant zeros. Another contribution re- gards the design of robust parity equations of any arbitrary order using both left and right eigenstructure assignment. Furthermore, a parity equation-based fault isolation and identification filter is designed which provides an estimate of the fault. A simple method for the calculation of thresholds whose violation indicates a fault occurrence is also proposed for the errors-in-variables framework.
33
Anitoaei, Teodora. "Enhancing Parking Behavior Detection." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-204502.
Анотація:
A review of navigation systems nowadays shows that new features are required in the automotive field. One such feature is suggesting a parking space within a positioning system. In the new global context of navigation, finding a parkingplace has become a central issue for all drivers. The research question for this study is what happens when you get to the destination or when you don’t need to use a GPS to arrive to your destination? This thesis has two major purposes:(1) to investigate an efficient solution for detecting the parking behavior of a moving car; (2) to implement and integrate an environment-friendly solution for HERE in a way that would give the company a competitive edge. By examining only the latitude and longitude from all the input GPS data received in a navigation system, the author defines the best configuration for a parking detection algorithm. Once the best configuration was found, an implementation was proposed. An extensive series of tests has been carried out on the final implementation. Data for tests was obtained using internal tools from HERE for producing different testing routes as navigation files (.nmea files). Creating the input files manually offers flexibility and gives the opportunity to touch all the unexpected behaviors, knowing the expected result in any case. The results obtained from the analysis of the algorithm are encouraging.It has been shown that the configuration chosen for implementation is cheap and effective in predicting parking behavior. In conclusion, the implementation of the algorithm was successfully integrated with the existing HERE SDK. The new feature will be available for the following three automotive companies: Audi, BMW, and Daimler. The algorithm is designed such that it can be easily extended and improved. Future work might include adding parameters that should be adjustable by the user or client like speed of the car.En genomgång av nutida navigationssystem visar att nya funktioner krävs för fordonsområdet. En sådan funktion är att föreslå en parkeringsplats inom ett positioneringssystem. I det nya globala sammanhanget för navigering har problemet att hitta en pa parkeringsplats blivit en central fråga för alla förare. Frågeställningen för denna studie är vad som händer när du kommer till destinationen eller när du inte behöver använda en GPS för att komma fram till din destination? Denna avhandling har två huvudsakliga syften: (1) att undersöka en effektiv lösning för detektering av parkeringsbeteende hos en bil som rör sig; (2) att genomföra och integrera en miljövänlig lösning för HERE på ett sätt som skulle ge bolaget en konkurrensfördel. Genom att endast undersöka latitud och longitud från all GPS-indata som mottags i ett navigationssystem definierar författaren den bästa konfigurationen för en parkeringdetekteringsalgoritm. När väl den bästa konfigurationen funnits föreslots ett genomförande. En omfattande serie tester har utförts på det slutliga genomförandet. Data för prov erhölls med hjälp av interna verktygfrån HERE för att producera olika provvägar som navigationsfiler (.nmea filer). Att skapa indatafiler manuellt erbjuder flexibilitet och ger möjlighet att vidröra alla oväntade beteenden, för att veta det förväntade resultatet i vilket fall som helst. De resultat som erhållits från analysen av algoritmen är uppmuntrande. Det har visats att konfigurationen som valts för genomförandet är billig och effektiv i att förutsäga parkeringsbeteende. Sammanfattningsvis har genomförandet av algoritmen framgångsrikt integrerats med den befintliga HERE SDK:n. Den nya funktionen kommer att finnas tillgänglig för följande tre bilföretag: Audi,BMW och Daimler. Algoritmen är utformad så att den lätt kan utvidgas och förbättras. Framtida arbete kan omfatta att lägga till parametrar som bör vara inställningsbara av användaren eller kunden som till exmpel hastigheten på bilen.
34
Kung, Chi-yau. "Fuzzy genetic modelling of air-conditioning systems for fault detection and diagnosis." Click to view the E-thesis via HKUTO, 2004. http://sunzi.lib.hku.hk/hkuto/record/B43895682.
35
Abboud, Layane. "Time Reversal techniques applied to wire fault detection and location in wire networks." Phd thesis, Supélec, 2012. http://tel.archives-ouvertes.fr/tel-00771964.
Анотація:
In this thesis we present new approaches in the domains of soft fault detection and location in complex wire networks, based on the properties of time reversal. When addressing the detection of soft faults, the idea is to adapt the testing signal to the network under test, instead of being predefined for all the tested networks, as opposed to standard reflectometry techniques. We prove that this approach, which we name the Matched Pulse approach (MP), is beneficial whenever the system is more complex, i.e., its response is richer in echoes, which is opposed to common understanding. The MP analysis is conducted via a formal mathematical analysis, followed by simulation and experimental results validating the proposed approach. In the domain of soft fault location, and based on the DORT (Décomposition de l'Opérateur de Retournement Temporel) properties, we derive a distributive non-iterative method able to synthesize signals that focus on the fault position. Through a statistical study we analyze some of the influencing parameters on the performance of the method, and then simulation and experimental results show that the method is able to synthesize signals directly focalizing on the soft fault position, without the need for iterations.
36
Du, Pisani Renaldo Murray. "Design of an Underwater Object Detection and Location System using Wide-Beam SONAR." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86236.
Анотація:
Thesis (MScEng)--Stellenbosch University, 2014.ENGLISH ABSTRACT: This thesis describes the second project relating to the development of a SONAR (SOund Navigation And Ranging) object detection and collision avoidance system for use on an AUV (Autonomous Underwater Vehicle) at Stellenbosch University. The main goal is to develop and test techniques that make use of the existing SONAR laboratory platform and wide-beam SONAR transducers to detect and locate objects and their limits/bounds under water in the horizontal plane. The results of the work done show that it is possible to use wide-beam transducers to locate the centroid and edges of a flat target with an error that is significantly smaller than the beam-width. The techniques developed will enable the development of a cost-effective SONAR system that can be implemented on an AUV.
AFRIKAANSE OPSOMMING: Hierdie tesis beskryf the tweede projek rakende die ontwikkeling van ’n SONAR voorwerp opsporings en botsingvermydingstelsel vir gebruik op ’n OOV (Outonome Onderwater Voertuig) aan die Universiteit van Stellenbosch. Die hoofdoel is om tegnieke te ontwikkel en te toets wat gebruik maak van die bestaande SONAR laboratorium opstelling en wye-straal SONAR opnemers om die posisie van voorwerpe onder water te bepaal, sowel as die posisie van die voorwerp se rande in die horisontale vlak. Die resultate van die werk wat gedoen is wys dat dit moontlik is om wye-straal opnemers te gebruik om die posisie van die sentroïde en rande van ’n plat voorwerp te vind met ’n fout wat aansienlik kleiner is as die straal-wydte. Die tegnieke wat ontwikkel is sal ons in staat stel om ’n koste-effektiewe SONAR stelsel te ontwikkel wat op ’n OOV geïmplenteer kan word.
37
Song, Lijun. "Detection and Position Location of Partial Discharges in Transformers Using Fiber Optic Sensors." Thesis, Virginia Tech, 2004. http://hdl.handle.net/10919/35928.
Анотація:
Power transformers are one of the most important components in the electrical energy network. Extending transformer life is very economically valuable due to power outage. Therefore the development of instruments to monitor the transformer condition is of great interest. Detection of partial discharges (PDs) in power transformers is an effective diagnostic because it may reveal and quantify an important aging factor and provide information on the condition of the transformer. However, partial discharge diagnostics are still not effectively used for online monitoring of transformers because of the complexity of PD measurements and difficulties of discriminating of PDs and other noise sources.
This thesis presents a further study of detection and location of partial discharges in power transformers based on previous work conducted at the Center for Photonics Technology (CPT) at Virginia Tech. The detection and positioning system consists of multiple extrinsic Fabry-Parot interferometric (EFPI) fiber acoustic sensors which can survive the harsh environment of oil-filled transformers.
This thesis work is focused on optimal arrangement of multiple sensors to monitor and locate PD activities in a power transformer. This includes the following aspects. First, the sensor design requirements are discussed in order to successfully detect and accurately position the PD sources. In the following sections, Finite Element Method (FEM) is used to model the EFPI sensor fabricated at CPT. Experiments were conducted to measure the angular dependence of the frequency response of the sensor. It is shown that within the range of ±45º incident angles, the sensitivity varies by 3-5dB. Finally, the thesis demonstrates a PD positioning experiment in a 500 gallon water tank (R à H = 74" à 30" cylinder) using a hyperbolic positioning algorithm and time difference of arrival (TDOA). Finally we demonstrated that 100% of the positioning data is bounded by a 22.7à 4.1à 5.3 mm3 cube, with a sensing range of 810 mm using the leading edge method with FIR filtering.Master of Science
38
Verdon-Roe, Gay Mary. "Development of a multi-location motion displacement test for detection of early glaucoma." Thesis, University College London (University of London), 2006. http://discovery.ucl.ac.uk/1445896/.
Анотація:
This thesis describes the development of a multi-location motion displacement test (MDT) for the early detection of glaucoma. The test uses line displacement stimuli, which are orientated with the retinal nerve fibre layer (RNFL) and scaled with ganglion cell density. Psychophysical properties of hyperacuity motion displacement were explored and results applied to optimize the stimulus presentation and test format. Investigations included the following: (i) Optical blur: MDT was found to be robust to peripheral astigmatism. The effect of spherical blur was quantified and the implication for discrimination between glaucoma and normal discussed. (ii) Spatial summation properties: equivalent MDT thresholds were demonstrated for equivalent length of single and multi-line stimuli. Equivalent MDT thresholds were also found for stimuli of equivalent energy ( stimulus area * stimulus luminance - background luminance ), in accordance with Ricco's Law. A linear relationship (slope 0.5) was found between log MDT threshold and log relative stimulus energy. A new law is proposed to apply to MDT summation properties, giving the relationship T = KVE T = MDT threshold K = constant E = stimulus energy . This may be used to predict MDT threshold for different configurations of stimuli. (iii) Shortening of response time was observed as stimulus duration is reduced and explained by altered temporal summation properties. The results were applied to modify the subject response window, with benefit of reduced test duration. (iv) Selection of stimulus number and position was made by study of attention, together with application of the anatomical relationship of the RNFL with the optic nerve head. (v) A staircase strategy was developed. Parameters were selected by analysis of results gained within the PhD and earlier studies. Results were pooled to accomplish an operational test. Preliminary assessment indicates that focal glaucomatous defects detected by standard automated perimetry are replicated by the new MDT.
39
Hu, Xi. "Network and sensor management for mulitiple sensor emitter location system." Diss., Online access via UMI:, 2008.
Анотація:
Thesis (Ph. D.)--State University of New York at Binghamton, Thomas J. Watson School of Engineering and Applied Science, Department of Electrical and Computer Engineering, 2008.Includes bibliographical references.
40
Yang, Zaiyue, and 楊再躍. "Fault detection, estimation and control of periodically excited nonlinear systems." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B40887984.
41
Halligan, Gary. "Fault detection and prediction with application to rotating machinery." Diss., Rolla, Mo. : Missouri University of Science and Technology, 2009. http://scholarsmine.mst.edu/thesis/pdf/Halligan_09007dcc80708356.pdf.
Анотація:
Thesis (M.S.)--Missouri University of Science and Technology, 2009.Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed November 25, 2009) Includes bibliographical references.
42
Gu, Xiaohan, and Ling Yang. "Face detection based on skin color." Thesis, Högskolan i Gävle, Avdelningen för Industriell utveckling, IT och Samhällsbyggnad, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-13767.
Анотація:
This work is on a method for face detection through analysis of photos. Accurate location of faces and point out the faces are implemented. In the first step, we use Cb and Cr channel to find where the skin color parts are on the photo, then remove noise which around the skin parts, finally, use morphology technique to detect face part exactly. Our result shows this approach can detect faces and establish a good technical based for future face recognition.
43
Miri, Seyed-Mehdi. "Modeling and fault detection in electromagnetic devices : applications to synchronous machines and signal conditioning systems /." The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487332636476273.
44
Markalous, Sacha M. "Detection and location of partial discharges in power transformers using acoustic and electromagnetic signals /." Göttingen : Sierke, 2007. http://deposit.d-nb.de/cgi-bin/dokserv?id=2958679&prov=M&dok_var=1&dok_ext=htm.
45
Drew, J. "Coalescence microseismic mapping : an imaging method for the detection and location of seismic events." Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.598649.
Анотація:
The Coalescence Microseismic Mapping method I have developed is applicable to event detection and location for a sparse array, while still benefiting from rigorous statistical analysis by averaging data over the array. Formulated within a Bayesian framework with respect to traveltime, the automated method simultaneously identifies and quantitatively images source location, by mapping a scalar signal that characterizes both the presence and timing of a seismic arrival. Unlike traveltime inversion, the numerical approach is not restrictive in regards to the type and distribution of errors. Effectively providing the probability density functions, the approach also allows for new ways to aggregate, visualize and interpret the results. Signal phase information can be assimilated in the solution when this can be recovered from the data, with the potential for improving location resolution. The method can be incorporated within a general integrated workflow, including an iterative or global inversion for multiple parameters. The theory is discussed in detail then applied to two datasets. The first is the integrated analysis of data acquired by a surface array deployed in the vicinity of Askja Volcano, Iceland. Here the signal phase information is recovered after correction for shear wave splitting and compensation for attenuation and station response. The second is for data acquired by a sub-surface array, monitoring seismic activity associated with hydraulic fracturing of a hydrocarbon reservoir. In this example the location is further constrained by including weighted signal polarization information in the search.
46
Linford, Paul William. "The application of signal processing techniques to leak detection and location in water pipes." Thesis, University of East Anglia, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250640.
47
Mok, Hing-tung. "Online fault detection and isolation of nonlinear systems based on neurofuzzy networks." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B39794064.
48
Mok, Hing-tung, and 莫興東. "Online fault detection and isolation of nonlinear systems based on neurofuzzy networks." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B39794064.
49
Kung, Chi-yau, and 龔子游. "Fuzzy genetic modelling of air-conditioning systems for fault detection and diagnosis." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B43895682.
50
Li, Shun Wen Jin. "A model-based fault detection and diagnostic methodology for secondary HVAC systems /." Philadelphia, Pa. : Drexel University, 2009. http://hdl.handle.net/1860/3136.