Tesi sul tema "Sensory distortion"

When I was an art school student, I was trained to pursue the likeness of subjects in all my artworks. This practice-based research explores alternative forms of self-expression in art practice. The exploration starts by questioning the relationship between perceptual devices, artists’ perceptions and artistic production. Most perceptual devices are designed to enhance artists’ sensory capabilities and facilitate the creation of art. Their success is often based on enabling artists to achieve a likeness of the subject drawn or making the creation of artefacts easier. My research focuses on investigating the consequences and artistic potential of applying sensory distortion devices that confuse, mislead and distort artists’ vision and kinesthesis, increasing the difficulty of making art, and exploring the productive potential of such devices to engender new creative forms. In this research three visual distortion devices and two kinaesthetic distortion devices are prototyped and used in experimental calligraphy, painting and drawing exercises. After analysing the artists’ experience of using these devices, the influence and artistic potential of applying them are examined. It is discovered that distorted vision and kinesthesis can greatly influence the making of art by disrupting habitual eye-hand coordination and control over producing artefacts. Besides which, the use of visual and kinaesthetic distortion devices can be a technique for new forms of artistic expression. It can also be an effective technique for creating serendipitous opportunities in the visual arts and a way of exploring and provoking reflection upon artistic methodologies. Consideration of the attributes of visual and kinaesthetic distortion devices and distorted perceptions during the process of prototyping can benefit the generation of ideas, methods of production and the contents of artworks. Some practical implications for creating art with visual and kinaesthetic distortion devices are also explored. They are discussed in relation to theories of human performance, such as flow theory, and attitudes toward the conflict between habitual and unfamiliar perceptual experience. Keeping an open and uncritical mind toward unfamiliarity, chaos and the accidents caused by distorted perceptions and reduced control of drawing instruments is suggested to working artists. Finally, this research contributes to art education by demonstrating a possible way of achieving self-exploration through art making.

Introduction : Les cognitions sensorielle, émotionnelle et sociale représentent le traitement des informations nécessaires à l'adaptation du sujet dans son environnement. Un psycho traumatisme est un évènement menaçant l'intégrité physique et psychique d'un individu et agit comme une « effraction » soudaine et intense de son système cognitif exposé au danger. Cette « effraction » entraine des atteintes cognitives provoquées par des altérations du système de neuromodulation des structures cérébrales impactées. Ces séquelles cognitives provoquent les symptômes qui constituent le trouble de stress post traumatique (TSPT) dont des troubles de perception. Le TSPT est associé à d'autres troubles psychiatriques comorbides dont le trouble psychotique. Notre travail propose l'hypothèse d'une compréhension clinique en « cascade » du psycho traumatisme. Il soutient l'idée que les cognitions sensorielle, émotionnelle et sociale s'articulent entre elles et avec l'environnement et participent à l'évolution du continuum entre psycho traumatisme et trouble psychotique.Méthodes : Nos travaux étudient la place des cognitions sensorielles, émotionnelles et sociales dans les troubles de perception post traumatiques illustrée par deux études de recherche clinique prospectives et longitudinales sur 6 mois. PROJET 1 : Identification des marqueurs de cognitions émotionnelle et sociale associés aux hallucinations acoustico-verbales (HAV) en population pédiatrique générale et en population pédiatrique clinique avec TSPT. PROJET 2 : Impact des troubles olfactifs persistants post Covid-19 sur la qualité de vie, l'expérience hédonique et les dimensions anxieuse et dépressives en population adulte.Résultats : PROJET 1 : L'étude réalisée en population pédiatrique générale a inclus 40 patients d'âge moyen 12,8 ans. Les émotions négatives (tristesse, peur colère) étaient significativement retrouvées dans le groupe avec des HAV persistantes à 6 mois. Les HAV persistantes étaient significativement associées au diagnostic de TSPT (p=0,01). L'étude réalisée en population pédiatrique clinique avec TSPT a inclus 31 patients d'âge moyen 12,9 ans. Les émotions négatives (culpabilité et malveillance des HAV) étaient significativement associées et corrélées à la persistance des HAV. Les émotions négatives (dégout, peur et colère et les diagnostics de dépression et d'anxiété) étaient associées à la persistance du TSPT à 6 mois. La persistance des HAV était significativement associée à l'émergence du diagnostic de trouble psychotique à 6 mois (p=0,01). PROJET 2 : L'étude a inclus 56 patients d'âge moyen 39 ans. Les troubles olfactifs étaient significativement associées à des émotions négatives (qualité de vie, perte de plaisir). Les patients avec une distorsion sensorielle (parosmie, phantosmie) étaient significativement impactés sur le plan émotionnel comparé aux patients qui présentaient une perte sensorielle (anosmie). Bien qu'ils aient retrouvés l'odorat au test psychophysique, les patients qui percevaient d'un trouble olfactif persistant répondaient aux symptômes de TSPT et étaient émotionnellement impactés (qualité de vie, perte de plaisir, anxiété et dépression).Conclusion : Les cognitions sensorielles et émotionnelles, après un évènement traumatique, sont significativement liées entre elles. Leur articulation participent à l'installation et au maintien des troubles de perception. Elles interviennent dans l'évolution de la clinique post traumatique, du TSPT et des troubles psychiatriques associés dont le trouble psychotique. L'évolution des symptômes post traumatiques nécessite une lecture dimensionnelle pour une meilleure compréhension clinique, un suivi préventif des facteurs de risques de mauvaise évolution psychiatrique et une proposition thérapeutique ciblée sur les cognitions sensorielles et émotionnelles
Introduction: Sensory, emotional and social cognition represent the processing of internal and external information required by the subject to adapt to the environment. A psycho-trauma is defined as an event that threatens the physical and psychological integrity of an individual, and acts as a sudden and intense intrusion of the cognitive system exposed to danger. This psycho-traumatic intrusion leads to sensory, emotional and social cognitive damage, caused by alterations in the neuromodulation system of the brain structures affected. These cognitive sequelae give rise to the post-traumatic symptoms that constitute post-traumatic stress disorder (PTSD), including perceptual disorders. PTSD is also associated with other comorbid psychiatric disorders, including psychotic disorders. Our work proposes the hypothesis of a "cascade" clinical understanding of psycho-trauma. It supports the idea that sensory, emotional and social cognition articulate with each other and with the environment, and participate in the evolution of the continuum between psycho-trauma and psychotic disorder.Methods: The aim of our research is to study the role of sensory, emotional and social cognition in post-traumatic perceptual disorders. This work is illustrated by two prospective, longitudinal 6-month clinical research studies. PROJECT 1: Identification of markers of emotional and social cognition associated with acoustic-verbal hallucinations (AVH) in the general pediatric population, then in the clinical pediatric population with PTSD. PROJECT 2: Impact of persistent post-Covid-19 olfactory disorders on quality of life, hedonic experience and anxiety and depression dimensions in an adult population.Results: PROJECT 1: The study, carried out in a general pediatric population, included 40 patients (30 girls, 10 boys) with a mean age of 12.8 years. Negative emotions (sadness, fear, anger) were significantly found in the group with persistent AVH at 6 months. Persistent AVH were significantly associated with the diagnosis of PTSD (p=0.01). The study conducted in a clinical pediatric population with PTSD included 31 patients (25 girls, 6 boys) with a mean age of 12.9 years. Negative emotions (patient guilt and maliciousness of HAV) were significantly associated and correlated with persistence of HAV. Negative emotions (disgust, fear and anger, and diagnoses of depression and anxiety) were also associated with PTSD persistence at 6 months. The persistence of HAV was significantly associated with the emergence of a diagnosis of psychotic disorder at 6 months (p=0.01). PROJECT 2: The study included 56 patients with a mean age of 39 (33 women, 23 men). Olfactory disorders were significantly associated and correlated with negative emotions (quality of life, loss of pleasure). Patients with sensory distortion (parosmia, phantosmia) were more significantly impacted emotionally than patients with no sensory perception (anosmia). Although they "objectively" recovered their sense of smell on the psychophysical test, patients who "subjectively" perceived the persistence of an olfactory disorder responded to PTSD symptoms and were more emotionally impacted (quality of life, loss of pleasure, anxiety and depression).Conclusion: Sensory and emotional cognitions are significantly linked after a traumatic event. Their articulation contributes to the onset and maintenance of perceptual disorders. They are also involved in the development of post-traumatic clinical symptoms, PTSD and other associated psychiatric disorders, including psychotic disorders. The evolution of post-traumatic symptoms requires a dimensional reading for a better clinical understanding, preventive monitoring of risk factors for poor psychiatric evolution, and a therapeutic proposal targeting sensory and emotional cognition

In this thesis, a novel anti-sensor network paradigm is introduced against wireless sensor networks (WSN). Anti-sensor network (ASN) aims to destroy application reliability by adaptively and anonymously introducing adequate level of artificial distortion into the communication of the event features transported from the sensor nodes (SN) to the sink. ASN is composed of anti-sensor nodes (aSN) randomly distributed over the sensor network field. aSNs pretend to be SNs tomaintain anonymity and so improve resiliency against attack detection and prevention mechanisms. Performance evaluations via mathematical analysis and simulation experiments show that ASN can effectively reduce the application reliability of WSN.

Thesis (M.A.) -- University of Maryland, College Park, 2006.
Thesis research directed by: Dept. of Kinesiology. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

In this paper a resilient sensor network is built in order to lessen the effects of a small portion of corrupted sensors when an aggregated result such as the average needs to be obtained. By examining the variance in sensor readings, a change in the pattern can be spotted and minimized in order to maintain a stable aggregated reading. Offset in sensors readings are also analyzed and compensated to help reduce a bias change in average. These two analytical techniques are later combined in Kalman filter to produce a smooth and resilient average given by the readings of individual sensors. In addition, principal components analysis is used to detect variations in the sensor network. Experiments are held using real sensors called MICAz, which are use to gather light measurements in a small area and display the light average generated in that area.

Over 800,000 people worldwide lost their lives to earthquakes in the last decade and on average 171 people die every day due to earthquake related damage to structures and buildings. Precisely understanding the effects ground motion has on manmade structures is crucial to making them earthquake resistant. This can only be achieved by the precise measurement, recording, and analysis of ground displacement trends during a seismic event. Although there is a vast amount of recorded seismological data available, current technology and processing methods fail to represent accurate ground displacement over time as the considerable technological challenges have yet to be overcome. Raw seismic data has so far been primarily acquired with instruments utilising geophone or accelerometer based sensors. These instruments produce prominent time domain displacement errors due to the various system and sensor inaccuracies, and due to non-linear response. Since accelerometers provide acceleration over time data: whilst geophones are velocimeters, and therefore provide velocity over time data; in order to derive true ground displacement over time, a double, or single numerical integration is required respectively. During this essential numerical integration processes of data from such sensors, even small in magnitude errors accumulate to yield rather large displacement trend offsets over a typical event recording period of 60 to 120 seconds. In addition, the numerical integration process itself poses considerable challenges due to the theoretically infinite number of samples and the accurate determination of initial conditions required for an exact mathematical result to be obtained. The latter, is currently performed by averaging an up to 60 second pre-event data trend stored on the instrument. Most post-integration data from current instruments appears to contain low frequency drifts amongst other noise artefacts, and generally requires baseline correction algorithms in an attempt to correct for these effects. Such corrections, although helpful, only aid to minimise the perceived effects of an assumed and collective source of error, and hence are largely unable to tackle the individual error contribution of each element within the system. Since individual element contribution is of a dynamic nature, the validity of these algorithms is limited by the accuracy of the initial assumptions made about a specific set of data. Faced with such a multivariable and uncertain dynamic behaviour, where even mathematical system modelling is of inadequate long term accuracy, a solution that aims to directly minimise these errors at source, rather than attempt to correct them postacquisition, is of immense importance when it comes to the recording, analysis, and understanding of earthquakes. This thesis describes the design, implementation, and evaluation of a High Precision Active Gyro Stabilised (HPAGS) sensor unit of exceptional performance for the provision of highly accurate ground displacement data. Experimental results demonstrated that the device described herein, was able to diminish the inherent non-linear and environment-dependant effects of current sensors, and thus was able to provide highly improved time domain displacement data.

This thesis documents a series of experiments designed to investigate the mechanisms subserving sub-second duration processing in humans. Firstly, duration aftereffects were generated by adapting to consistent duration information. If duration aftereffects represent encoding by neurons selective for both stimulus duration and non-temporal stimulus features, adapt-test changes in these features should prevent duration aftereffect generation. Stimulus characteristics were chosen which selectively target differing stages of the visual processing hierarchy. The duration aftereffect showed robust interocular transfer and could be generated using a stimulus whose duration was defined by stimuli invisible to monocular mechanisms, ruling out a pre-cortical locus. The aftereffects transferred across luminance-defined visual orientation and facial identity. Conversely, the duration encoding mechanism was selective for changes in the contrast-defined envelope size of a Gabor and showed broad spatial selectivity which scaled proportionally with adapting stimulus size. These findings are consistent with a second stage visual spatial mechanism that pools input across proportionally smaller, spatially abutting filters. A final series of experiments investigated the pattern of interaction between concurrently presented cross-modal durations. When duration discrepancies were small, multisensory judgements were biased towards the modality with higher precision. However, when duration discrepancies were large, perceived duration was compressed by both longer and shorter durations from the opposite modality, irrespective of unimodal temporal reliability. Taken together, these experiments provide support for a duration encoding mechanism that is tied to mid-level visual spatial processing. Following this localised encoding, supramodal mechanisms then dictate the combination of duration information across the senses.

Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009.
Committee Chair: Ghassan AlRegib; Committee Member: Elliot Moore; Committee Member: Monson H. Hayes; Committee Member: Paul A. Work; Committee Member: Ying Zhang. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Abstract Wireless sensor networks (WSNs) consisting of battery-powered sensors are increasingly deployed for a myriad of Internet of Things applications, e.g., environmental, industrial, and healthcare monitoring. Since wireless access is typically the main contributor to battery usage, minimizing communications is crucial to prolong network lifetime and improve user experience. The objective of this thesis is to develop and analyze energy-efficient distributed compressed data acquisition techniques for WSNs. The thesis proposes four approaches to conserve sensors' energy by minimizing the amount of information each sensor has to transmit to meet given application requirements. The first part addresses a cross-layer design to minimize the sensors’ sum transmit power via joint optimization of resource allocation and multi-path routing. A distributed consensus optimization based algorithm is proposed to solve the problem. The algorithm is shown to have superior convergence compared to several baselines. The remaining parts deal with compressed sensing (CS) of sparse/compressible sources. The second part focuses on the distributed CS acquisition of spatially and temporally correlated sensor data streams. A CS algorithm based on sliding window and recursive decoding is developed. The method is shown to achieve higher reconstruction accuracy with fewer transmissions and less decoding delay and complexity compared to several baselines, and to progressively refine past estimates. The last two approaches incorporate the quantization of CS measurements and focus on lossy source coding. The third part addresses the distributed quantized CS (QCS) acquisition of correlated sparse sources. A distortion-rate optimized variable-rate QCS method is proposed. The method is shown to achieve higher distortion-rate performance than the baselines and to enable a trade-off between compression performance and encoding complexity via the pre-quantization of measurements. The fourth part investigates information-theoretic rate-distortion (RD) performance limits of single-sensor QCS. A lower bound to the best achievable compression — defined by the remote RD function (RDF) — is derived. A method to numerically approximate the remote RDF is proposed. The results compare practical QCS methods to the derived limits, and show a novel QCS method to approach the remote RDF
Tiivistelmä Patterikäyttöisistä antureista koostuvat langattomat anturiverkot yleistyvät esineiden internetin myötä esim. ympäristö-, teollisuus-, ja terveydenhoitosovelluksissa. Koska langaton tiedonsiirto kuluttaa merkittävästi energiaa, kommunikoinnin minimointi on elintärkeää pidentämään verkon elinikää ja parantamaan käyttäjäkokemusta. Väitöskirjan tavoitteena on kehittää ja analysoida energiatehokkaita hajautettuja pakattuja datankeruumenetelmiä langattomiin anturiverkkoihin. Työssä ehdotetaan neljä lähestymistapaa, jotka säästävät anturien energiaa minimoimalla se tiedonsiirron määrä, mikä vaaditaan täyttämään sovelluksen asettamat kriteerit. Väitöskirjan ensimmäinen osa tarkastelee protokollakerrosten yhteissuunnittelua, jossa minimoidaan anturien yhteislähetysteho optimoimalla resurssiallokaatio ja monitiereititys. Ratkaisuksi ehdotetaan konsensukseen perustuva hajautettu algoritmi. Tulokset osoittavat algoritmin suppenemisominaisuuksien olevan verrokkejaan paremmat. Loppuosat keskittyvät harvojen lähteiden pakattuun havaintaan (compressed sensing, CS). Toinen osa keskittyy tila- ja aikatasossa korreloituneen anturidatan hajautettuun keräämiseen. Työssä kehitetään liukuvaan ikkunaan ja rekursiiviseen dekoodaukseen perustuva CS-algoritmi. Tulokset osoittavat menetelmän saavuttavan verrokkejaan korkeamman rekonstruktiotarkkuuden pienemmällä tiedonsiirrolla sekä dekoodausviiveellä ja -kompleksisuudella ja kykenevän asteittain parantamaan menneitä estimaatteja. Työn viimeiset osat sisällyttävät järjestelmämalliin CS-mittausten kvantisoinnin keskittyen häviölliseen lähdekoodaukseen. Kolmas osa käsittelee hajautettua korreloitujen harvojen signaalien kvantisoitua CS-havaintaa (quantized CS, QCS). Työssä ehdotetaan särön ja muuttuvan koodinopeuden välisen suhteen optimoiva QCS-menetelmä. Menetelmällä osoitetaan olevan verrokkejaan parempi pakkaustehokkuus sekä kyky painottaa suorituskyvyn ja enkooderin kompleksisuuden välillä mittausten esikvantisointia käyttäen. Neljäs osa tutkii informaatioteoreettisia, koodisuhde-särösuhteeseen perustuvia suorituskykyrajoja yhden anturin QCS-järjestelmässä. Parhaimmalle mahdolliselle pakkaustehokkuudelle johdetaan alaraja, sekä kehitetään menetelmä sen numeeriseen arviointiin. Tulokset vertaavat käytännön QCS-menetelmiä johdettuihin rajoihin, ja osoittavat ehdotetun QCS-menetelmän saavuttavan lähes optimaalinen suorituskyky

Dans le cadre de la robotique mobile extérieure, les notions de perception et de localisation sont essentielles au fonctionnement autonome d'un véhicule. Les objectifs de ce travail de thèse sont multiples et mènent vers un but de localisation et de cartographie simultanée d'un environnement extérieur dynamique avec détection et suivi d'objet mobiles (SLAMMOT) à l'aide d'un unique capteur extéroceptif tournant de type radar dans des conditions de circulation dites "réalistes", c'est-à-dire à haute vitesse soit environ 30 km/h. Il est à noter qu'à de telles vitesses, les données acquises par un capteur tournant son corrompues par le déplacement propre du véhicule. Cette distorsion, habituellement considérée comme une perturbation, est analysée ici comme une source d'information. Cette étude vise également à évaluer les potentialités d'un capteur radar de type FMCW (onde continue modulée en fréquence) pour le fonctionnement d'un véhicule robotique autonome. Nous avons ainsi proposé différentes contributions : - une correction de la distorsion à la volée par capteurs proprioceptifs qui a conduit à une application de localisation et de cartographie simultanées (SLAM), - une méthode d'évaluation de résultats de SLAM basées segment, - une considération de la distorsion des données dans un but proprioceptif menant à une application SLAM, - un principe d'odométrie fondée sur les données Doppler propres au capteur radar, - une méthode de détection et de pistage d'objets mobiles : DATMO avec un unique radar.

Les progrès réalisés en systèmes micro-électro-mécaniques couplés avec leur convergence vers les systèmes de communication sans fil, ont permis l'émergence des réseaux de capteurs sans fil (RCSF). Les contraintes de ces réseaux font que tous les efforts soient fournis pour proposer des solutions économes en énergie. Avec les récents développements des technologies CMOS, des capteurs d'images à faible coût ont été développés. En conséquence, un nouveau dérivé des RCSF, qui sont les Réseaux de Capteurs Vidéo Sans Fil (RCVSF), a été proposé. La particularité des données vidéo ainsi que les contraintes inhérentes aux nœuds ont introduit de nouveaux défis. Dans cette thèse, nous proposons deux solutions basées sur l'approche inter-couches pour la livraison de la vidéo sur les RCVSF. La première solution propose un nouveau schéma de compression vidéo adaptatif, efficace en énergie et basé sur la norme de compression vidéo H.264/AVC. Le flux vidéo est ensuite géré par une version améliorée du protocole MMSPEED que nous proposons et notons EQBSA-MMSPEED. Les résultats des simulations montrent que la durée de vie du réseau est étendue de 33%, tout en améliorant la qualité du flux vidéo reçu de 12%. Dans la deuxième solution, nous enrichissons le schéma de compression de modèles mathématiques pour prévoir la consommation d'énergie et la distorsion de l'image lors des phases d'encodage et de transmission. Le flux vidéo est géré par un nouveau protocole de routage efficace en énergie et à fiabilité améliorée noté ERMM. Comparée à une approche basique, cette solution réalise une extension de la durée de vie du réseau de 15%, tout en améliorant la qualité du flux vidéo reçu de 35%
Thanks to the valuable advances in Micro Electro-Mechanical Systems coupled with their convergence to wireless communication systems, the Wireless Sensor Networks (WSN). In the WSN context, all the efforts are made in order to propose energy-efficient solutions. With the recent developments in CMOS technology, low-cost imaging sensors have been developed. As a result, a new derivative of the WSN, which is the Wireless Video Sensor Network (WVSN), has been proposed. The particularities of the video data as well as the inherent constraints of the nodes have introduced new challenges. In this thesis, we propose two cross-layer based solutions for video delivery over the WVSN. The first solution proposes a new energy efficient and adaptive video compression scheme dedicated to the WVSNs, based on the H.264/AVC video compression standard. The video stream is then handled by an enhanced version of MMSPEED protocol, that we propose and note EQBSA-MMSPEED. Performance evaluation shows that the lifetime of the network is extended by 33%, while improving the video quality of the received stream by 12%. In the second solution, we enrich our compression scheme with mathematical models to predict the energy consumption and the video distortion during the encoding and the transmission phases. The video stream is then handled by a novel energy efficient and improved reliability routing protocol, that we note ERMM. Compared to a basic approach, this solution is extending the network lifetime by 15%, while improving the quality of the received video stream by 35%

碩士
國立臺灣科技大學
電機工程系
103
In recent years, with the smart phone popularizing, the resolution of its built-in camera is up to 500 million~1300 million pixels, it has gradually replaced the digital camera and become the most popular portable device which was used to take pictures or video. However, when using a smart phone to take pictures or videos, unlike a previously used digital camera, sometimes skew distortion occurs in the screen. The key reason is the builtin sensors of digital camera are mostly charge-coupled device(CCD), which take global shutter mode to capture images, so that there will be no skew/wobble/partial exposure effect. Handset developers choose complementary metal-oxide-semiconductor(CMOS) sensor which used rolling shutter due to cost, and it will result in the above problems. The paper analyzed skew distortion and come up with the improvement proposal. Solutions proposed previously based on using skew parameter and global motion vector(GMV) to automatically recover the skew screen, the disadvantages of which are the selected GMV is easily misjudged in some cases. In this thesis, the accelerometer data measured by g-sensor is converted into displacement, it is equal to camera displacement,replacing the displacement GMV represents. Skew parameter and camera displacement was used to fix skew distortion result from rolling shutter CMOS sensor video in a quickly-moving camera directly, and rebuild the missing pixels. Simulation results show that the proposed method effectively reduces the skew distortion caused by rolling shutter. Because camera offset could be easily converted through the acceleration into the displacement, compared to the complex process to get GMV, it can not only effectively reduce the complexity of the algorithm but also rule out the false positives probably caused by the selection of GMV in a particular screen.

碩士
國立中正大學
通訊工程研究所
96
In this paper, we consider the problem of lifetime-distortion tradeoff in wireless sensor network. From the resource limitation of sensor node, we categorize the problem into two subproblems: (OBJ 1) As transmission rate R is fixed, finding a minimal distortion D* for a given transmission rate; (OBJ 2) As maximal allowed distortion is fixed, finding a minimal transmission rate R* for a given distortion. We use vector quantization technique to solve these two objective functions. The goal is to minimize the average transmission rate for spatial correlated sensor data. The static and dynamic traffic of sensor data are considered in this paper. When the sensor data is static traffic we formulate mathematic models (distortion rate model and rate distortion model) to determine the optimal solutions (D* and R*), while the sensor data is dynamic traffic the algorithms (distortion rate algorithm and rate distortion algorithm) are used instead, which reduces the computational complexity. Although the algorithm is guaranteed to converge to a local minimum, it is possible to arrive at the global minimum by repeated applications of the algorithm with different initializations. The performance analysis is conducted under two difference data patterns: uniform distribution U(a, b) and normal distribution N(mu ,sigma^2).

博士
國立交通大學
電信工程系所
97
This dissertation presents the layout design, nonlinear modeling and sensing application in terms of active device. The active device, such as MOSFET or BJT in semiconductor, is one of the most important components of a wireless communication or sensing system generally. It plays a significant part in determining the overall performance, cost, and reliability of these application systems. In the world of RF wireless communications, the base-stations and long range transmitters use silicon laterally-diffused MOS (LDMOS) high power transistors almost exclusively. To achieve lower on-resistance and a more compact device size, this study adopted an annular structure in the layout design. According to the measurement results, the smaller drain parasitic resistance in the annular structure could be the key factor for improving ft and fmax. In additional to the small-signal analysis, the large-signal characteristics, such as power gain and power added efficiency, were also improved compared to the transitional structure of LDMOS. In addition to high power device design, the behavior model of the nonlinear characteristics for active device is also crucial. In this study, we analyze the polyharmonic distortion model (PHD) and use this model to predict the nonlinear behavior of active device. By way of the PHD model extracted using on-wafer nonlinear vector network analyzer (NVNA), the large-signal validation of this model also shows a good match with measurements at 1.9 GHz without optimization and curve fitting. In another part of this thesis, we discussed and analyzed the sensor design completely using CMOS active device and SAW delay-line device. Their electrical characteristics are evaluated as well as vapor sensing results. The sensing experimental results show that the maximum oscillation frequency shift between gas on and off is approximately 10 kHz with 50 x 103 ppm alcohol vapor concentration. Conclusions on the sensing device and system, and recommendations concerning potential improvements of these components are discussed, finally.

In this thesis, a method of distortion analysis of electromagnetic field sensors using orthogonal polynomial subspaces is presented. The effective height of the sensor is viewed as the impulse response of a linear system. The impulse response corresponds to a linear transformation which maps every electromagnetic incident field waveform to a received voltage waveform. Hermite and Laguerre orthogonal polynomials are used as the basis sets for the subspace of incident electromagnetic field waveforms. Using the selected basis set, a transformation matrix is calculated for the sensors. The transformation matrices are compared to a reference transformation matrix as a measure of distortion. The transformation matrices can describe the sensor behavior up to a certain frequency range. The limits on this frequency range are investigated for both Hermite-Gauss and Laguerre functions. The unique property of Laguerre functions is used to prove that the transformation matrix has a particular pattern. This method is applied on case studied sensors both in computer simulation and measurements.

Whether for work or leisure, we see a large number of people traveling by train every day. In order to ensure the comfort and safety of passengers, it must be checked whether the composition is working normally. For this purpose, a constant monitoring of a train must be done, followed by a diagnosis of the com-position, prediction of failures and production of alarms in the event of any anomaly. To perform monitoring on a train, it is necessary to collect data from sensors distributed along its carriages and send them to a software system that performs the diagnosis of the composition in a fast and efficient way. The description of the activities necessary for monitoring of a train imme-diately refers to topics such as distributed systems, since the intended system will have to integrate several sensors distributed along the train, or Smart Systems, since each sensor must have the capacity to not only acquire data, but also trans-mit it, preferably, wirelessly. However, there are some obstacles to the implementation of such a system. Firstly, the existence of sources of distortions and noise in the medium interferes both in the acquisition and transmission of data and secondly the fact that the sensors distributed along the train are not prepared to be connected directly to a software system. This dissertation seeks to find a solution for the problems described by im-plementing a data acquisition system that is distributed and takes advantage of the current technologies of low-cost sensor nodes as well as web technologies for sensor networks.

Documentos apresentados no âmbito do reconhecimento de graus e diplomas estrangeiros
Induction machines are one the most important electrical equipment in industrial plants and manufacturers. They have a great variety of features, structures and performance. So, proper and secure protection design and fault detection are important issues. The induction machines are divided into two categories as squirrel-cage and wound-rotor types. Due to many advantages of squirrel cage motors (e.g. simplicity, lower cost, less maintenance and etc.) they are the most common choice for industries. However, wound rotor induction motors have their own applications, where they have high start-up torque for industries such as hoist, cement and steel ones. According to the fault destructive effects on induction motors, fault detection and the related region identification in early stages are the most important protection criteria. In this thesis, monitoring of the air-gap flux and measuring the rotational magnetic field distortion and asymmetricity caused by stator or rotor Turnto-Turn fault is regarded as the main parameter to detect such faults. To achieve such aim, some simple flux sensors are installed in the specified stator slots, so that each phase equipped by two flux sensors aligned with the magnetic axis of the related coils. In motor healthy condition, passing fluxes from the corresponding sensors are equal, which results in the identical induced voltages in them and then difference of them (i.e. Δ ) is equal to zero. In case of stator or rotor winding Turn-to-Turn fault, Δ will no longer be zero due to rotational magnetic field distortion and such phenomenon is the main criterion to detect the faulty condition and discriminate the stator or rotor winding faults, in this thesis. To demonstrate the capability of this method, not only the simulation results but also the experimental test results have been used. The ability to detect and discriminate rotor and stator winding Turn-to-Turn fault, faulty phase detection in the cases of stator faults, low processing burden and high sensitivity in the face of permissible voltage unbalance and mechanical load variation are the undeniable advantages of this method, which can be pointed out.

碩士
國立臺北科技大學
電機工程系研究所
100
The objective of this thesis is to develop a new modulation technique which can reduce the current distortion and extend the current reconstruction range for three-phase inverter using only DC-link sensor. The PWM technique is a hybrid method which consists of space vector modulation method and the PWM method without using null switching states. The former provides low current distortion, however it is with narrower current reconstruction range. In contrast, the later extends the current reconstruction range at the cost of higher current distortion. The proposed method, in the measurable region of space vector modulation method, space vector modulation is used to reduce the current distortion. Moreover, as the modulation range is out of that measurable region, the PWM method without using null switching states is applied to extend the current reconstruction range, and achieve the current reconstruction of the three-phase inverter. In this thesis, an ALTERA produced Field Programmable Gate Array (FPGA) EPF10K70RC240-3 is used as the control platform. This proposed method for current reconstruction is realized using induction motor (IM). An induction motor with specifications of rated power 750 W, rated speed 1680 RPM, no. of poles 4, rated frequency 60 Hz, rated voltage 220/380 V(ê/Y), rated current 3.1/1.8 A. Finally, the experimental results will confirm the effectiveness of the proposed method, where the current can be reconstructed even under very low modulation index with low harmonics distortion of inverter output current.