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Shaun, Ferdous Jahan. "Multi-Parameters Miniature Sensor for Water Network Management." Thesis, Paris Est, 2018. http://www.theses.fr/2018PESC1138/document.
Повний текст джерелаАнотація:
L’eau est une ressource vitale, indispensable à la vie sur terre. A l’instar de nombreuses autres ressources naturelles, l’eau propre à la consommation est soumise à une forte pression à cause de l’impact de l’activité humaine d’une part et de l’augmentation continue de la population mondiale d’autre part. Une pression tellement forte que l’eau propre représente l’un des 17 objectifs de développement durable des Nations Unies. Dans ce contexte, une gestion rationnelle et durable de la ressource s’avère indispensable. Dans ce but, un système intelligent de supervision des réseaux d’eau potable peut s’avérer très utile. Les systèmes existant sont toutefois peu intégrés et compacts, nécessitent souvent une alimentation externe, et restent relativement chers pour un déploiement massif sur les réseaux. La présente thèse s’inscrit dans le cadre d’un projet de recherche européen, PROTEUS, visant à pallier ces différents problèmes en mettant au point un système de mesure pour la supervision de la ressource en eau permettant la mesure de 9 paramètres physico-chimiques, reconfigurable, et énergétiquement autonome. La contribution de la présente thèse à ce projet porte sur la conception et l’optimisation des différents capteurs physiques (conductivité électrique, pression, température et débit) ainsi qu’à leur co-intégration sur une même puce. Le système proposé montre des performances au moins égales à celle de l’état de l’art en ce qui concerne la robustesse, assurée par la redondance de nombreux éléments sensibles, le domaine de sensibilité et la consommation énergétique. Le présent manuscrit est par conséquent construit comme suit : le premier chapitre est une introduction générale à la supervision de grandeurs environnementales et à la puce multi-capteurs. Le second chapitre décrit la structure de la puce multi-capteurs ainsi que les méthodes de fabrication utilisées, avec une attention particulière accordée aux capteurs de pression et de conductivité électrique. Le troisième chapitre porte sur l’utilisation de résistances électriques pour la mesure de diverses grandeurs physiques, notamment la température. Le dernier chapitre s’attarde plus particulièrement sur l’utilisation de ce type de résistances pour la mesure de débit avant de conclure et de proposer des perspectives pour des travaux futursWater is a vital element for every living being on the earth. Like many other dwindling natural resources, clean water faces a strong pressure because of human activity and the rapid growth of global population. The situation is so critical that clean water has been identified as one of the seventeenth sustainable development goals of the United Nations. Under these conditions, a sustainable management of water resources is necessary. For this purpose, a smart solution for water networks monitoring can be very helpful. However, commercially available solutions lack compactness, self-powering capabilities cost competitiveness, necessary to enable the large rollout over water networks. The present thesis takes place in the framework of a European research project, PROTEUS, which addresses these different problems by designing and fabricating a multi-parameter sensor chip (MPSC) for water resources monitoring. The MPSC enables the measurement of 9 physical and chemical parameters, is reconfigurable and self-powered. The present thesis addresses more precisely physical sensors, their design, optimization and co-integration on the MPSC. The developed device exhibits state of the art or larger performances with regard to its redundancy, turn-down ratio and power consumption. The present manuscript is split into two main parts: Part-I and Part-II. Part-I deals with non-thermal aspects of the MPSC, the pressure and conductivity sensor for instance, as well as the fabrication process of the whole device (Chapter 1 and 2). The background of environmental monitoring is presented in Chapter 1 along with the State of Art review. Chapter 2 describes fabrication methods of the MPSC. Preliminary characterization results of non-thermal sensors are also reported in this chapter. Chapter 3 and 4, included in Part-II, deal with thermal sensors (temperature and flow-rate). Chapter 3 describes the many possible uses of electric resistances for sensing applications. Finally, in chapter four, we focus on flowrate sensors before concluding and making a few suggestions for future works
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Bergmark, Giesler Linn. "Investigating construction and design parameters of an embroidered resistive pressure sensor." Thesis, Högskolan i Borås, Akademin för textil, teknik och ekonomi, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-26450.
Повний текст джерелаАнотація:
Electronic textiles, or smart textiles, is a field that is growing due to the opportunities it provides. Textile integrated electronics enables soft, flexible, lightweight electronic devices that enable long term monitoring within the medical field. Pressure sensors is one device within this field that has been researched. A textile integrated pressure sensor enables monitoring of heart rate, muscle activity, posture, gait phases and finger movements. In this project a resistive pressure sensor has been produced using embroidery with the purpose of investigating how construction and design parameters influence the resistance-pressure relationship. The study consisted in different phases where in Phase I parameters such as fabric substrate, stitch length and yarn type was examined. Phase II investigated design parameters like electrode pattern design, sensor shape, trace distance and size. In the design phase a new electrode pattern and sensor shape was tested. Finally in Phase III a sensor matix and sensor chain was constructed in order to evaluate the possibility of obtaining touch location. The findings in this study showed that the shape, size and yarn type had the most distinct influence on the sensor performance in regards to the resistance-pressure relationship. In an additional recovery test the results indicated that both textile substrate and stitch length could influence the ability to recover to its original shape after applying cyclic pressure. It was also found that the new pattern design performed equally to the conventional pattern designs and at the same time reduced material consumption as well as the embroidery time. The sensor matrix and sensor chain could display a change in resistance when applying a weight at each sensing element, implying that touch location could be detected, but would need further development in construction before potential implementation.
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Statz, C., J. Küttner, D. Plettemeier, and Thomas Herlitzius. "SEBIMO - Microwave-based Measurement of Soil Parameters." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-229895.
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Kailayanathan, Subaharan, and Saji Kamdod. "Development of Generic Communication Middleware for Embedded Sensor Systems Transmitting Health Parameters." Thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-49017.
Повний текст джерелаАнотація:
Health technology or e-Health is one of the most rapidly growing areas in healthcare today and it has been an important requirement as a new concept of healthcare industry. Since global society has been changed to aging society and the healthcare cost has been increasing in the 21st century since 2007. As the total number of people aged 65 or older is expected to increase from 12% to 22% in 2050 which is double the rate, and at the same time there is a decrease in in-fertility rates and increase in life expectancy due to the increase in life quality, there is a need to investigate the needs and requirements of an intelligent embedded sensor systems in health applications, and to develop a new communication protocol or set of protocols that can be used to send data collected from a hub within a house, home-care or a complex and send it securely and reliably to a central database where the gathered data can be monitored by a medical professional to make decisions for further interventions. The employed communication protocol should also be able to securely transmit confidential parameters from the hospital network to a central server outside of the hospital network. The final protocol must be inline with the regulations of the EU. This thesis is done in collaboration with Tjeders AB, Stille AB, and Embedded Sensor Systems for Health Plus (ESS-H+) research profile at Mälardalen University. In this thesis, different communication protocols such as IPSec and TLS and algorithms such as AES and RSA are examined and based on the requirements provided by the companies certain of these protocols and algorithms will be used in the final implementation. Different performance metrics such as overhead, round trip delay and throughput will be measured for the chosen communication protocols and recommendations will be given on which of the protocols and algorithms needs to be used to obtain an optimized, secure and reliable network.
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Chaudhari, Qasim Mahmood. "Estimation of clock parameters and performance benchmarks for synchronization in wireless sensor networks." [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-2945.
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OKUMA, Shigeru, Tatsuya SUZUKI, Takashi MUTOU, and Eiji KONAKA. "Optimal Design of Sensor Parameters in PLC-Based Control System Using Mixed Integer Programming." Institute of Electronics, Information and Communication Engineers, 2005. http://hdl.handle.net/2237/14990.
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Cao, Huiyi. "Remote Gait Monitoring Mobile System Enabled by Wearable Sensor Technology." Case Western Reserve University School of Graduate Studies / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=case1587042096284549.
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Bäcklund, Tomas. "Development and validation of a system for clinical assessment of gait cycle parameter in patients with idiopathic normal pressure hydocephalus." Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-82891.
Повний текст джерелаАнотація:
A number of parameters have been identified as characteristic of the walking pattern in patients with INPH. Most of these have been identified through qualitative surveys and manually conducted test batteries. In order to obtain quantitative, standardized and objective measures, which enable studies based on larger patient populations and comparable results, there is a need for a user-friendly system that can measure specific key parameters over time in a reliable manner in everyday clinical work. Step height, width and the variability in the gait cycle are such parameters which are interesting research areas for this group of patient. Problems with balance and gait are very common in other patient groups as well, particularly in neurological diseases such as Parkinson's disease, multiple sclerosis and stroke. This is the reason that the development of this gait analyzer is performed. Giving access to a simple and objective method for estimating gait and balance ability in clinical routine investigations would increase the ability to provide the right kind of treatment, confirm treatment results, and conducting larger research studies. Therefore, this equipment can contribute to the assessment of diseases which contain impaired gait. As a first test of the usability and for the validation of accuracy and repeatability of the equipment a group of healthy volunteers was used. Results from tests on healthy subjects show god repeatability between measurements, for step width at normal gait the difference was -0,2 ±0,34 cm (mean, ±SD) and step height 0,69 ±3,34 cm. The stride time variability in the healthy group where very small 0,00048 ±0,00028 s2 with a difference between test of 0,000019 ±0,00038 s2. Three pilot patients have been tested where we have clearly seen indications of increased stride time variability and reduced step height.
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Atalay, Ozgur. "Development and investigation of weft knitted strain sensor." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/development-and-investigation-of-weft-knitted-strain-sensor(54fffacb-d1d7-4e9e-9d8f-7f33d4b90d66).html.
Повний текст джерелаАнотація:
This thesis presents a study of the sensing properties exhibited by textile-based knitted strain sensors. Sensing fabrics were manufactured from silver-plated conductive nylon and non-conducting elastomeric yarns. The component yarns offered similar diameters, bending characteristics and surface friction, but their production parameters differed in respect of the yarn input tension, the number of conductive courses in the sensing structure and the elastomeric yarn extension characteristics. The knitted sensors were manufactured using flat-bed knitting technology, and electro-mechanical tests were performed on the specimens using a tensile testing machine to apply strain whilst the sensor was incorporated into a Wheatstone bridge arrangement to allow electrical monitoring. The novel operational principle relies on the separation under strain of adjacent conducting knitted loops which are normally held in contact by the elastomeric yarn. The results confirm that production parameters play a fundamental role in determining the physical behaviour and the sensing properties of knitted sensors and the response could be engineered by varying the production parameters of specific designs. Results showed that the knitted structures could be manipulated to produce gauge factor values between 2.26 and 0.23 for sensors with working ranges of 8.4 % and 3.3 % respectively when the elastomeric yarn had 8 cN input tension. The generated signals were stable and repeatable, and under cyclic testing proved to be substantially free from long-term drift. A textile-based strain sensor was developed to create a respiration belt; this was realised by bringing together the extensible knitted sensor and a relatively inelastic textile strap. Machine simulations and real time measurements on a human subject were performed to calculate average breathing frequencies under different static and dynamic conditions. Various respiration rates were monitored to simulate different medical conditions and with the belt located either round the torso or in the abdominal area, the sensor yielded a satisfactory response. However, body motion artefacts affected the signal quality under dynamic conditions and an additional signal-processing step was added to separate unwanted interference from the breathing signal. Electro-mechanical modelling was developed by exploiting Peirce`s loop model in order to describe the fabric geometry under static and dynamic conditions. Kirchhoff`s node and loop equations were employed to create a generalised solution for the equivalent electrical resistance of the textile sensor for a given knitted loop geometry and for a specified number of loops. Experimental results were obtained from the sensor for strain levels up to 40% and these correlate well with the modelled data; a maximum error of 2.13 % was found between the experimental and modelled resistance-strain relationships.
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Li, Zeyuan. "Target localization using RSS measurements in wireless sensor networks." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/31356.
Повний текст джерелаАнотація:
The subject of this thesis is the development of localization algorithms for target localization in wireless sensor networks using received signal strength (RSS) measurements or Quantized RSS (QRSS) measurements. In chapter 3 of the thesis, target localization using RSS measurements is investigated. Many existing works on RSS localization assumes that the shadowing components are uncorrelated. However, here, shadowing is assumed to be spatially correlated. It can be shown that localization accuracy can be improved with the consideration of correlation between pairs of RSS measurements. By linearizing the corresponding Maximum Likelihood (ML) objective function, a weighted least squares (WLS) algorithm is formulated to obtain the target location. An iterative technique based on Newtons method is utilized to give a solution. Numerical simulations show that the proposed algorithms achieves better performance than existing algorithms with reasonable complexity. In chapter 4, target localization with an unknown path loss model parameter is investigated. Most published work estimates location and these parameters jointly using iterative methods with a good initialization of path loss exponent (PLE). To avoid finding an initialization, a global optimization algorithm, particle swarm optimization (PSO) is employed to optimize the ML objective function. By combining PSO with a consensus algorithm, the centralized estimation problem is extended to a distributed version so that can be implemented in distributed WSN. Although suboptimal, the distributed approach is very suitable for implementation in real sensor networks, as it is scalable, robust against changing of network topology and requires only local communication. Numerical simulations show that the accuracy of centralized PSO can attain the Cramer Rao Lower Bound (CRLB). Also, as expected, there is some degradation in performance of the distributed PSO with respect to the centralized PSO. In chapter 5, a distributed gradient algorithm for RSS based target localization using only quantized data is proposed. The ML of the Quantized RSS is derived and PSO is used to provide an initial estimate for the gradient algorithm. A practical quantization threshold designer is presented for RSS data. To derive a distributed algorithm using only the quantized signal, the local estimate at each node is also quantized. The RSS measurements and the local estimate at each sensor node are quantized in different ways. By using a quantization elimination scheme, a quantized distributed gradient method is proposed. In the distributed algorithm, the quantization noise in the local estimate is gradually eliminated with each iteration. Simulations show that the performance of the centralized algorithm can reach the CRLB. The proposed distributed algorithm using a small number of bits can achieve the performance of the distributed gradient algorithm using unquantized data.
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Yussof, Hanafiah, Masahiro Ohka, Abdul Rahman Omar, and Muhammad Azmi Ayub. "Determination of Object Stiffness Control Parameters in Robot Manipulation Using a Prototype Optical Three-Axis Tactile Sensor." IEEE, 2008. http://hdl.handle.net/2237/12138.
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Thomas, George George. "Extraction of Follow up Parameters of Bone Density Microwave Sensor from Post Craniotomy and Lower Extremity Trauma Rehabilitation Measurements." Thesis, Uppsala universitet, Institutionen för informationsteknologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-348887.
Повний текст джерелаАнотація:
Longitudinal microwave based sensor systems facilitates frequent follow ups in scenarios where healing information is largely missing. An example is neonatalcraniotomy where Computerized Tomography (CT) information is available mostly before surgery and up to three years after that. In such case, frequent CT’s cannot betaken due to multitude of reasons ranging from dosage concerns to sheer cost. In this context, the use of a follow-up modality could substantially improve the quality of life. Bone Density Measurement Analysis (BDAS) and Complex Fracture Orthopaedic Rehabilitation (COMFORT) are two such projects dealing with collecting vital information that will help in addressing the unknown physiological changes. Compliant to ethical approvals 200 low extremity trauma patients from Holland and23 craniosynostosis patients from Sweden, were enrolled in clinical trials for theCOMFORT and BDAS projects respectively. For COMFORT study, itself, it involves200 (patients) x 3 (low extremity locations) x 5 (Repetition) x 9 (time points) =27000 data sets. Similarly, the BDAS projects deals with 966 data sets. Microwave Sensors measure how the signal reflected from target area for a given set offrequency (1GHz to 3GHz). As can be seen, there is a big volume of data that is prone to error during repeated measurements and useful information in terms ofmutual variability between test subjects, targets, time points etc. In this study the follow-up parameters to monitor the physiological changes are identified and are extracted from the large volume of raw data. This is done by delimiting the initial data between 2.3 GHz to 2.6 GHz. It was seen from simulation, error estimation and previous works that the above-mentioned frequency range contains the needed information. Then the delimited data is averaged for its magnitude and phase with respect to frequency. An algorithm for finding the minimum value of the averaged delimited data (resonance) is implemented for the dB magnitude and compared withrespect to time points. A sub function is created to derive the polar coordinates(absolute magnitude, phase in radiance) and the Cartesian coordinates (in thecomplex plane). A preliminary analysis was performed on the processed data and some basic postulations were made. This work segregates the follow up parameters from raw data which can be used in future in depth analysis of clinical outcomes.
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Slovák, Martin. "Monitorování parametrů prostředí v budovách." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2010. http://www.nusl.cz/ntk/nusl-218721.
Повний текст джерелаАнотація:
Aim of work is project system for monitoring environmental parameters in buildings. Theoretical part of work deals with parameters, which will be monitoring, why we measure those parameters in buildings. And what devices can we choose to do it. Measurement channel describes from change of physical value to electric value, after that there is a correction to processing by microcontroller. And those values are sending by microcontroller to other processing. The best solution to distant transmission is probably ZigBee technology. Practice part of work is in keeping with theoretical part. There are some practical sensor connections, where is difference in output of sensor. It’s necessary to project connections of sensor and do their software services. There is a simple tool to programming microcontrollers, which is called CodeWarrior. In last part is solution of algorithm, which make net by ZigBee technology.
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Fendri, Ahmed. "Impedimetric Sensor System for Edible Oil Quality Assessment." Universitätsverlag Chemnitz, 2019. https://monarch.qucosa.de/id/qucosa%3A37173.
Повний текст джерелаАнотація:
The repeated usage of frying oil is hazardous due to the degradation caused by chemical reactions, which happen while heating. The total polar compounds and the free fatty acids are the main two chemical parameters affected by frying. These parameters increase significantly with the use of oil for frying and are reported as reasons for causing serious illnesses like heart diseases.
For this purpose, sensor systems for oil quality assessment are necessary. In fact, changes of the composition due to frying leads to variation of its dielectric parameters. This can be measured using a capacitive sensor and the measurement of its impedance change. The main challenge thereby is that the impedance changes are very small and stray capacitances have a big influence on the measurements.
In this context, this work proposes a sensor system with high accuracy able to detect the small changes that occur in the resistance and capacitance under influence of stry capacitances. Theoretical and simulation studies are carried out for different cap acitive sensors as well as meas urement procedures of its cornp lex imp edance.
The sensor should provide a high sensitivity to relative perrnittivity and the electrical conductiv ity, and at the same time a small size and a high reproducibility. Interdigital electrodes sensor with a suitable design fulfils all these requirements.
A deep consideration of stray capacitances is needed to realize an accurate sensor system. For t hese reasons, the design of the measurement circuit is crucial within this work. We propose, a measurernent circuit based on a combinat ion of the method of capacitance to voltage conversion and the phase shift measurement method. By cornbining both rnethods together it is possible to rneasure accurate ly the complex irnpedance of edible oil. Experimental results show that measurement systern is capable to detect small changes of dielectric parameters, which are correlated to the chemical parameters.Die mehrfach wiederholte Verwendung von Frittieröl ist aufgrund der Qualitätsver schlechterung, die während des Erhitzens auftreten durch chemische Reaktionen verursacht wird, gefährlich für die Gesundheit. Die totale polaren Kompon enten und die freien Fettsäuren sind die zwei wichtigsten chemischen Komponenten, die wesentlich durch das Braten beeinflusst werden. Diese Komponenten erhöhen sich signifikant mit der Wiederverwendung von Bratöl und verursachen u. a. ernste Herzkrankheiten. Diese Arbeit zielt darauf hin, ein mobiles, kostengünstiges, einfach zu verwenden des Sensorsystem für die Abschätzung der Ölqualität zu entwickeln. Das System charakterisiert die Veränderung der elektrischen Parameter des Öls durch Messung der Änderung seiner komplexen elektrischen Eigenschaft en. In dieser Arbeit wurde ein Sensorelement mit interdigitalen Elektroden entwickelt, der eine hohe Empfindlichkeit auf die relative Permittivität und die elektrischen Leitfähigkeit des Öls hat und dabei einer hohe Reproduzierbarkeit erzielen kann. Es wird ein Messverfahren vorgeschlagen, das auf der Wandlung in einer Spannung und einer Phasenverschiebung basiert. Sowohl durch theoretische Überlegungen als auch durch Simulationen konnte belegt werden, dass die Kombination beider Metho den eine akkurate Messung der Komplexem Imped anz hochdielektrischer Materia lien ermöglichen kann. Experiment elle Ergebnisse zeige n, dass das Messsystem in der Lage ist , kleine Änderungen der dielektrischen Parameter zu erfassen, die mit den chemischen Ölparamtern stark korrelieren.
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Bayram, Alican. "Identification Of Kinematic Parameters Using Pose Measurements And Building A Flexible Interface." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614819/index.pdf.
Повний текст джерелаАнотація:
Robot manipulators are considered as the key element in flexible manufacturing systems. Nonetheless, for a successful accomplishment of robot integration, the robots need to be accurate. The leading source of inaccuracy is the mismatch
between the prediction made by the robot controller and the actual system. This work presents techniques for identification of actual kinematic parameters and pose accuracy compensation using a laser-based 3-D measurement system. In identification stage, both direct search and gradient methods are utilized. A computer simulation of the identification is performed using virtual position measurements. Moreover, experimentation is performed on industrial robot FANUC Robot R-2000iB/210F to test full pose and relative position accuracy improvements.
In addition, accuracy obtained by classical parametric methodology is improved by the implementation of artificial neural networks. Neuro-parametric method proves an enhanced improvement in simulation results. The whole proposed theory is reflected by developed simulation software throughout this work while achieving accuracy nine times better when comparing before and after implementation.
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Ruy, Roberto da Silva [UNESP]. "Desenvolvimento e validação geométrica de um sistema para mapeamento com câmeras digitais de médio formato." Universidade Estadual Paulista (UNESP), 2008. http://hdl.handle.net/11449/100268.
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Made available in DSpace on 2014-06-11T19:30:32Z (GMT). No. of bitstreams: 0
Previous issue date: 2008-11-19Bitstream added on 2014-06-13T19:00:45Z : No. of bitstreams: 1
ruy_rs_dr_prud.pdf: 5800893 bytes, checksum: eca044ea30603eb3cacb3a982ca7088c (MD5)Nos últimos anos observa-se uma crescente utilização de câmaras digitais em Fotogrametria, especialmente os modelos profissionais de câmaras de pequeno e médio formato. Isso porque os sistemas digitais comerciais de grande formato possuem custos elevados e um complexo sistema de gerenciamento, armazenamento e processamento das imagens. Além disso, as câmaras digitais de pequeno e médio formato possuem algumas vantagens que as tornam altamente atrativas, como: grande disponibilidade no mercado; flexibilidade quanto ao intervalo de focalização; são pequenas, leves e de fácil manejo e; possuem custos substancialmente reduzidos quando comparadas aos sistemas digitais de grande formato. Por outro lado, algumas limitações ainda estão presentes nestes modelos de câmaras, no que se refere à confiabilidade da geometria interna e à resolução dos sensores. Contudo, estudos de caso têm mostrado que estes problemas podem ser contornados, podendo-se utilizar todo o potencial deste tipo de sensor para mapeamentos temáticos, topográficos e cadastrais em áreas de pequeno e médio porte, com grande flexibilidade em relação aos sensores aéreos e orbitais convencionais. Neste contexto, este trabalho teve como objetivo a concepção, implementação física e testes reais de um sistema de aquisição de imagens digitais, formado por câmaras digitais de médio formato integradas a sensores de orientação direta, dispositivos eletrônicos e interfaces de hardware e software. Foram desenvolvidos também estudos, análises, algoritmos e programas computacionais de Fototriangulação com parâmetros adicionais (FPA), com dados de georreferenciamento direto, voltados ao sistema desenvolvido...
In the last years there is a growing use of digital cameras in Photogrammetry, mainly the small and medium format cameras, because of high cost and problems with the images management and postprocessing in the high end digital cameras. Besides, if the small and medium format cameras are calibrated they can provide quality data, together with their advantages: variety in the market; focalization flexibility; are small, light, easy handling and; have low cost if compared with the high resolution cameras. Although, these models of digital cameras have some limitations, like the interior orientation reliability and the resolution of the sensor. Some case studies have showed that these problems can be solved and the digital sensors can be used with success in thematic, topographic and cadastral mapping of small and medium areas, with high flexibility if compared with conventional aerial and orbital sensors. In this context, the aim of this work is the conception, development and real tests performing of a digital image acquisition system composed by medium format digital cameras integrated to direct orientation systems, electronic devices and hardware and software developments. Studies, analysis and computational programs related to block triangulation with additional parameters with direct orientation data were performed for establishing the interior orientation of the cameras that compose the acquisition system... (Complete abstract click electronic access below)
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Slováková, Kristína. "Studium ochranných vlastností fóliových a nánosovaných materiálů." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2009. http://www.nusl.cz/ntk/nusl-216474.
Повний текст джерелаАнотація:
The report deals with the study of the resistence of the nonporous polymer materiále against permeation of the selected TICs, with the analysis of the running difussion processes and utilization of the acquired results for the selection of suitable barrier materials for the protective means.
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Abdelzaher, Ahmed F. "Identifying Parameters for Robust Network Growth using Attachment Kernels: A case study on directed and undirected networks." VCU Scholars Compass, 2016. http://scholarscompass.vcu.edu/etd/4481.
Повний текст джерелаАнотація:
Network growing mechanisms are used to construct random networks that have structural behaviors similar to existing networks such as genetic networks, in efforts of understanding the evolution of complex topologies. Popular mechanisms, such as preferential attachment, are capable of preserving network features such as the degree distribution. However, little is known about such randomly grown structures regarding robustness to disturbances (e.g., edge deletions). Moreover, preferential attachment does not target optimizing the network's functionality, such as information flow. Here, we consider a network to be optimal if it's natural functionality is relatively high in addition to possessing some degree of robustness to disturbances. Specifically, a robust network would continue to (1) transmit information, (2) preserve it's connectivity and (3) preserve internal clusters post failures. In efforts to pinpoint features that would possibly replace or collaborate with the degree of a node as criteria for preferential attachment, we present a case study on both; undirected and directed networks. For undirected networks, we make a case study on wireless sensor networks in which we outline a strategy using Support Vector Regression. For Directed networks, we formulate an Integer Linear Program to gauge the exact transcriptional regulatory network optimal structures, from there on we can identify variations in structural features post optimization.
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Einloft, Diego. "Projeto automático de controlador de velocidade sem sensor mecânico para motores de indução trifásicos." Universidade Federal de Santa Maria, 2008. http://repositorio.ufsm.br/handle/1/8456.
Повний текст джерелаАнотація:
Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorThis works proposes parameters estimation algorithm to auto-tune the control laws of a speed sensorless servo. The identification process of the electrical and mechanical parameters is based on recursive least squares method (RLS) and utilizes just measured stator currents. The electrical parameters are obtained by the transfer function of the motor with locked rotor. Hence, this eliminates the need to realize classical tests for the electrical parameters obtention and impose robustness to the controller for parameters variations caused by aging of materials. Thus, the electrical parameters are used to project the current controllers and the rotor speed is estimated by a model reference adaptive systems (MRAS). The structure of MRAS is composed by two systems (reference model and adaptive system) based on instantaneous reactive power and using an adaptation mechanism. On the other hand, to obtain a robust control when the system is subject to disturbances or load s variations, mechanical parameters are identified using estimated rotor speed and mechanical model of the induction motor (IM). Finally, for the speed control is used a proportional plus integral controller (PI) self-tuned through the estimated inertia.
Este trabalho propõe um algoritmo de identificação paramétrica para auto-ajuste da lei de controle de um servo de velocidade sem sensor mecânico. O processo de identificação dos parâmetros elétricos e mecânicos do servo é baseado em algoritmos do tipo mínimos quadrados recursivo (RLS) e utiliza apenas as medidas das correntes estatóricas. Os parâmetros elétricos são identificados através da função de transferência do motor com rotor bloqueado. Isso elimina a necessidade de realizar ensaios clássicos para obtenção dos parâmetros elétricos e impõe robustez ao controlador frente a variações paramétricas que ocorrem devido aos desgastes e envelhecimento dos materiais que constituem o motor. Uma vez identificados, os parâmetros elétricos são utilizados no projeto dos controladores de corrente e a velocidade rotórica é estimada utilizando um sistema adaptativo por modelo de referência (MRAS). A estrutura do MRAS é composta por dois sistemas (modelo de referência e sistema adaptativo) baseados na potência reativa instantânea e utiliza um mecanismo de adaptação. Por outro lado, para impor robustez ao controlador frente a variações de carga, os parâmetros mecânicos são identificados a partir da velocidade rotórica estimada e do modelo mecânico do motor de indução (MI). Finalmente, para o controle de velocidade é usado um controlador proporcional e integral (PI) com seus ganhos sintonizados a partir da inércia estimada.
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Ruy, Roberto da Silva. "Desenvolvimento e validação geométrica de um sistema para mapeamento com câmeras digitais de médio formato /." Presidente Prudente : [s.n.], 2008. http://hdl.handle.net/11449/100268.
Повний текст джерелаАнотація:
Orientador: Antonio Maria Garcia TommaselliBanca: Edson Aparecido Mitishita
Banca: Jorge Luis Nunes e Silva Brito
Banca: Julio Kiyoshi Hasegawa
Banca: Mauricio Galo
Resumo: Nos últimos anos observa-se uma crescente utilização de câmaras digitais em Fotogrametria, especialmente os modelos profissionais de câmaras de pequeno e médio formato. Isso porque os sistemas digitais comerciais de grande formato possuem custos elevados e um complexo sistema de gerenciamento, armazenamento e processamento das imagens. Além disso, as câmaras digitais de pequeno e médio formato possuem algumas vantagens que as tornam altamente atrativas, como: grande disponibilidade no mercado; flexibilidade quanto ao intervalo de focalização; são pequenas, leves e de fácil manejo e; possuem custos substancialmente reduzidos quando comparadas aos sistemas digitais de grande formato. Por outro lado, algumas limitações ainda estão presentes nestes modelos de câmaras, no que se refere à confiabilidade da geometria interna e à resolução dos sensores. Contudo, estudos de caso têm mostrado que estes problemas podem ser contornados, podendo-se utilizar todo o potencial deste tipo de sensor para mapeamentos temáticos, topográficos e cadastrais em áreas de pequeno e médio porte, com grande flexibilidade em relação aos sensores aéreos e orbitais convencionais. Neste contexto, este trabalho teve como objetivo a concepção, implementação física e testes reais de um sistema de aquisição de imagens digitais, formado por câmaras digitais de médio formato integradas a sensores de orientação direta, dispositivos eletrônicos e interfaces de hardware e software. Foram desenvolvidos também estudos, análises, algoritmos e programas computacionais de Fototriangulação com parâmetros adicionais (FPA), com dados de georreferenciamento direto, voltados ao sistema desenvolvido... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: In the last years there is a growing use of digital cameras in Photogrammetry, mainly the small and medium format cameras, because of high cost and problems with the images management and postprocessing in the high end digital cameras. Besides, if the small and medium format cameras are calibrated they can provide quality data, together with their advantages: variety in the market; focalization flexibility; are small, light, easy handling and; have low cost if compared with the high resolution cameras. Although, these models of digital cameras have some limitations, like the interior orientation reliability and the resolution of the sensor. Some case studies have showed that these problems can be solved and the digital sensors can be used with success in thematic, topographic and cadastral mapping of small and medium areas, with high flexibility if compared with conventional aerial and orbital sensors. In this context, the aim of this work is the conception, development and real tests performing of a digital image acquisition system composed by medium format digital cameras integrated to direct orientation systems, electronic devices and hardware and software developments. Studies, analysis and computational programs related to block triangulation with additional parameters with direct orientation data were performed for establishing the interior orientation of the cameras that compose the acquisition system... (Complete abstract click electronic access below)
Doutor
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Reinecke, Sebastian Felix. "Instrumentierte Strömungsfolger zur Prozessdiagnose in gerührten Fermentern." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-137598.
Повний текст джерелаАнотація:
Advanced monitoring of the spatio-temporal distribution of process parameters in large-scale vessels and containers such as stirred chemical or bioreactors offers a high potential for the investigation and further optimization of plants and embedded processes. This applies especially to large-scale fermentation biogas reactors where the process performance including the biological processes highly depend on mixing parameters of the complex bio-substrates. Sufficient mixing is a basic requirement for a stable operation of the process and adequate process performance. However, this condition is rarely met in agricultural biogas plants and the process efficiency is often reduced dramatically by inhomogeneities in the agitated vessels. Without a doupt, investigation and monitoring of biochemical parameters, such as the fermentation rate, pH distribution as well as O2 and CO2 concentration is of great importance. Nevertheless, also understanding of non-biological parameters, such as fluid dynamics (flow velocity profiles, circulation times), suspension mixing (homogeneity, location of dead zones and short-circuits) and heat transfer (temperature profiles), is necessary to analyze the impact of mixing on the biological system and also to improve the process efficiency.
However, in most industrial scale applications the acquisition of these parameters and their spatial distributions in the large-scale vessels is hampered by the limited access to the process itself, because sensor mounting or cable connections are not feasible or desired. Therefore, state of the art instrumentation of such reactors is commonly limited to few spatial positions where it is doubtfully assumed that the measured parameters are representative for the whole reaction mixture.
In this work, a concept of flow following sensor particles was developed. The sensor particles allow long-term measurement of spatially distributed process parameters in the chemically and mechanically harsh environments of agitated industrial vessels. Each sensor particle comprises of an onboard measurement electronics that logs the signals of measurement devices, namely temperature, absolute pressure (immersion depth, axial position) and 3D acceleration. The whole electronics is enclosed in a robust neutrally buoyant capsule (equivalent diameter 58.2 mm; sphericity 0.91), to allow free movement with the flow.
The sensor particles were tested in pilot fermenters under comparable flow conditions of biogas fermenters. The experiments proved the applicability of the sensor particles and the robustness to resist the harsh environments of mixing processes. Moreover, the results show the capabilities of the sensor particles to monitor the internal conditions of the vessel correctly and thus deliver significant information about the flow regime. Therefore effects of liquid rheology, vessel geometry, impeller speed and axial impeller position on the macro-mixing process were properly detected. Evaluation of the impeller efficiency and the mixing processes was done based on mixing homogeneity, location of dead zones, axial velocity profiles, circulation time distributions as well as average circulation times, acceleration spectra and temperature profiles that were extracted from the measured data. Furthermore, it is shown, that parameters of mixing models such as circulation number, impeller head, PECLÉT-number and variance of suspended solid particles can be estimated from the measured data.
The main achievement of this work is therefore the development and validation of instrumented flow followers for the investigation of macro-mixing effects in agitated vessels. The sensor particles show potential for employment to real applications such as biogas fermenters or large bioreactors and to monitor and improve the mixing and heating regimes.
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Durante, Gabriel. "Desenvolvimento de uma rede de sensores sem fio para processamento de sinais acústicos marinhos." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/3/3142/tde-12112018-084935/.
Повний текст джерелаАнотація:
O crescente interesse pela caracterização de parâmetros acústicos marinhos esbarra nos poucos dispositivos eletrônicos que permitem capturar, armazenar, processar e difundir dados. Os equipamentos atuais que possibilitam obter dados referentes à vida marinha e permitem estudar as influências humanas sobre ela possuem alto custo e funcionam de forma isolada, ou seja, normalmente não há comunicação com outros dispositivos, o que dificulta a monitorização de eventos em tempo real. Sendo assim, neste trabalho são revisadas as características necessárias para estabelecer uma rede de sensores sem fio (RSSF) de alta confiabilidade, utilizando-se o conceito de Internet das Coisas (IoT). São comparados os protocolos MQTT-SN e CoAP com ferramentas de simulação e implementada uma rede de sensoriamento acústico aquático constituída de três nós sensores autônomos e um gateway usando o protocolo 6LowPAN. Também é implementada a tradução para o protocolo IPV4 no gateway, de modo que o funcionamento da rede de sensores pode ser monitorada num servidor remoto na Internet em tempo real. O desempenho da rede é avaliado com relação à autonomia energética, capacidade de memória, alcance e confiabilidade na entrega dos dados. As unidades autônomas desenvolvidas podem operar ininterruptamente, com uso de baterias, por aproximadamente 125 horas com memória de gravação de 48GB e alcance de 100m aproximadamente. Por fim, é implementado o pré-processamento dos dados sonoros visando a detecção de eventos acústicos aquáticos.The increasing interest in the characterization of marine acoustic parameters needs electronic devices that allow capture, store, process, and diffuse data. Current equipment that provides data about the marine life and allow the study of human influences on it have high cost and work isolated, that is, without communication with other devices, which makes it difficult to monitor events in real time. Therefore, this work revises the necessary features to establish a high reliability wireless sensor network (WSN) by applying the concept of Internet of Things (IoT). The protocols MQTT-SN and CoAP are compared with simulation tools and a network is implemented to sense acoustic signals, composed by three autonomous sensor nodes and a gateway using the protocol 6LowPAN. The translation for the IPV4 protocol in the gateway is also implemented, so the operation of the sensor network can be monitored by a remote server on the Internet in real time. The performance of the network is evaluated in relation to power autonomy, memory capacity, reach and reliability. The autonomous sensor nodes can operate uninterrupted, with use of batteries, for approximately 125 hours with 48GB storage for recording and approximately 100m range. Finally, data pre-processing is implemented in order to detect aquatic acoustic events.
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Nguyen, Van Tri. "Adjoint-based approach for estimation & sensor location on 1D hyperbolic systems with applications in hydrology & traffic." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAT063/document.
Повний текст джерелаАнотація:
Ce travail de thèse propose une approche générique pour l'estimation de l'état/ des paramètres et pour le placement de capteurs de systèmes hyperboliques non linéaires en dimension infinie. Le travail est donc divisé en deux parties principales : une partie consacrée à l'estimation optimale et une partie dédiée au placement optimal de capteurs. La méthode d'estimation optimale utilise une approche par calcul des variations et utilise la méthode des multiplicateurs de Lagrange. Ces multiplicateurs jouent un rôle important en donnant accès aux sensibilités des mesures par rapport aux variables qui doivent être estimées. Ces sensibilités, décrites par les équations adjointes, sont aussi à l'origine d'une nouvelle approche, dite méthode de l'adjoint, pour le placement optimal de capteurs. Divers exemples, construits sur la base de simulations mais également de données réelles et pour différents scénarios, sont aussi étudiées afin d'illustrer l'efficacité des approches développées. Ces exemples concernent les écoulements à surface libre (en hydrologie des bassins versants) et le trafic routier représentés par des équations aux dérivées partielles hyperboliques non linéairesThe thesis proposes a general framework for both state/parameters estimation and sensor placement in nonlinear infinite dimensional hyperbolic systems. The work is therefore divided into two main parts: a first part devoted to the optimal estimation and a second one to optimal sensor location. The estimation method is based on the calculus of variations and the use of Lagrange multipliers. The Lagrange multipliers play an important role in giving access to the sensitivities of the measurements with respect to the variables to be estimated. These sensitivities, described by the adjoint equations, are also the key idea of a new approach, so-called the adjoint-based approach, for the optimal sensor placement. Various examples, either based on some simulations with synthetic measurements or real data sets and for different scenarios, are also studied to illustrate the effectiveness of the developed approaches. Theses examples concern the overland flow systems and the traffic flow, which are both governed by nonlinear hyperbolic partial differential equations
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Bandarupalli, Sowmya. "Vehicle detection and tracking using wireless sensors and video cameras." ScholarWorks@UNO, 2009. http://scholarworks.uno.edu/td/989.
Повний текст джерелаАнотація:
This thesis presents the development of a surveillance testbed using wireless sensors and video cameras for vehicle detection and tracking. The experimental study includes testbed design and discusses some of the implementation issues in using wireless sensors and video cameras for a practical application. A group of sensor devices equipped with light sensors are used to detect and localize the position of moving vehicle. Background subtraction method is used to detect the moving vehicle from the video sequences. Vehicle centroid is calculated in each frame. A non-linear minimization method is used to estimate the perspective transformation which project 3D points to 2D image points. Vehicle location estimates from three cameras are fused to form a single trajectory representing the vehicle motion. Experimental results using both sensors and cameras are presented. Average error between vehicle location estimates from the cameras and the wireless sensors is around 0.5ft.
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Hedric, Andrew C. "Dynamic Behaviors of Historical Wrought Iron Truss Bridges – a Field Testing Case Study." Thesis, University of North Texas, 2015. https://digital.library.unt.edu/ark:/67531/metadc822751/.
Повний текст джерелаАнотація:
Civil infrastructure throughout the world serves as main arteries for commerce and transportation, commonly forming the backbone of many societies. Bridges have been and remain a crucial part of the success of these civil networks. However, the crucial elements have been built over centuries and have been subject to generations of use. Many current bridges have outlived their intended service life or have been retrofitted to carry additional loads over their original design. A large number of these historic bridges are still in everyday use and their condition needs to be monitored for public safety. Transportation infrastructure authorities have implemented various inspection and management programs throughout the world, mainly visual inspections. However, careful visual inspections can provide valuable information but it has limitations in that it provides no actual stress-strain information to determine structural soundness. Structural Health Monitoring (SHM) has been a growing area of research as officials need to asses and triage the aging infrastructure with methods that provide measurable response information to determine the health of the structure. A rapid improvement in technology has allowed researchers to start using new sensors and algorithms to understand the structural parameters of tested structures due to known and unknown loading scenarios. One of the most promising methods involves the use of wireless sensor nodes to measure structural responses to loads in real time. The structural responses can be processed to help understand the modal parameters, determine the health of the structure, and potentially identify damage. For example, modal parameters of structures are typically used when designing the lateral system of a structure. A better understanding of these parameters can lead to better and more efficient designs. Usually engineers rely on a finite element analysis to identify these parameters. By observing the actual parameters displayed during field testing, the theoretical FE models can be validated for accuracy. This paper will present the field testing of a historic wrought iron truss bridge, in a case study, to establish a repeatable procedure to be used as reference for the testing of other similar structures.
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Carotenuto, Adriano Roberto da Silva. "Comparação da reatividade de carvões em reatores ciclônicos." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2013. http://hdl.handle.net/10183/79848.
Повний текст джерелаАнотація:
Um novo laboratório experimental desenvolvido para investigar a combustão de carvão em atmosferas de oxicombustão é descrito em detalhes na tese. Um reator ciclônico é utilizado para a combustão de carvões de baixo rank em condições de escoamento turbulento e com swirl, e operando em temperaturas similares às encontradas em câmaras de combustão industriais. Um sensor potenciométrico de oxigênio, instalado dentro do reator ciclônico, é utilizado para medir o consumo de oxigênio durante a combustão das amostras de carvão. Amostras de carvão com alto teor de cinzas, das minas do Leão e Bonito localizadas no sul do Brasil, e amostras de carvão linhito pré-seco (LTBK), da região da Lusácia, na Alemanha, foram submetidos à combustão em atmosferas de ar e de oxicombustão (O2/CO2/H2O). Os experimentos foram realizados em três temperaturas médias do gás de combustão: 1073, 1173 e 1273 K. Para as amostras do carvão LTBK, a oxicombustão foi composta com duas atmosferas de O2/CO2 sem vapor d’água (21/79 e 30/70) e três atmosferas de O2/CO2/H2O (30/60/10, 30/50/20 e 30/40/30) em base molar, enquanto para as amostras dos carvões Leão e Bonito, a oxicombustão foi composta com duas atmosferas de O2/CO2 (21/79 e 30/70). As amostras de carvão foram peneiradas para uma faixa de tamanho de partículas de 1250 a 2000 μm e 125 a 500 μm, e com massas de 1g e 3g. Em adição aos testes, amostras de char dos carvões Leão e LTBK foram preparadas para investigar o comportamento da combustão de suas matrizes carbonosas com diferentes níveis de matéria volátil. Primeiramente, a investigação da combustão do carvão é feita diretamente a partir das curvas de concentração de oxigênio medidas para a combustão das amostras de carvão LTBK submetidos às atmosferas de ar e oxicombustão com vapor d’água, conforme explicado no Capítulo 2 desta tese. Entretanto, devido ao grande número de experimentos realizados e a necessidade de entender a influência dos fatores, como temperatura e as composições das atmosferas oxidantes, e as interações entre esses fatores na combustão do carvão, a análise pela metodologia do Projeto de Experimentos (DoE) é aplicada nos experimentos, conforme detalhado no Capítulo 3. A reatividade dos carvões de baixo rank é investigada por meio do cálculo dos parâmetros cinéticos globais e dos coeficientes da taxa de reação de combustão do char, considerando a hipótese de um reator bem misturado, a ser verificada ao longo da investigação, conforme descrito no Capítulo 4. A partir da análise das curvas de concentração de oxigênio (Capítulos 2 e 3), os resultados mostram que a atmosfera de oxicombustão com 79% de CO2 (21/79, O2/CO2) aumenta o consumo de oxigênio para os carvões de alto teor de cinzas, Bonito e Leão, e para o carvão linhito com alto teor de voláteis (LTBK), devido à influência da reação de gaseificação do CO2 a partir de temperaturas acima de 1073 K. A partir da análise dos parâmetros cinéticos globais calculados para avaliar a reatividade dos carvões, os resultados mostram que a hipótese do reator bem misturado não é o suficiente para capturar a cinética da combustão do carvão por batelada no interior do reator ciclônico. A reatividade dos carvões investigados, através das constantes efetivas da taxa de reação, variando-se a composição da atmosfera oxidante, temperatura do gás de combustão, tamanho de partículas, massa da amostra e posição do sensor de oxigênio, têm influência do escoamento com swirl e seus termos advectivos e difusivos.A novel laboratory facility designed to investigate coal oxy-fuel combustion is described in the present work. A cyclone chamber allows for the combustion of low-rank coal under turbulent conditions and swirling flows, covering a temperature range similar to those found on practical furnaces. A potentiometric oxygen sensor with oxide-ion conducting solid electrolytes, as stabilized zirconia, installed within the cyclone reactor, is used to measure the oxygen consumption during the combustion of coal samples. High ash coals samples, from Leão and Bonito mining sites located in South Brazil, and pre-dried lignite coal samples (LTBK), from the Lusatian region, in Germany, were burned under air and oxy-fuel (O2/CO2/H2O) atmospheres. Experiments were carried out at three average gas combustion temperatures: 1073, 1173 and 1273 K. For LTBK coal, oxy-fuel combustion was composed with two O2/CO2 atmospheres (21/79 and 30/70) and three O2/CO2/H2O atmospheres (30/60/10, 30/50/20 and 30/40/30) in molar basis, whereas for Leão and Bonito coals, the oxy-fuel combustion was composed with two O2/CO2 atmospheres (21/79 and 30/70). Coal samples were sieved to a size range of 1250 to 2000 μm and 125 to 500 μm and with 1g and 3g. In addition, char samples from Leão and lignite coals were prepared in order to investigate the combustion behavior of its carbon matrix for different levels of volatile matter. The investigation of coal combustion behavior is made firstly directly on the oxygen concentration curves measured for LTBK coal samples burned under air and oxy-fuel atmospheres with water vapor, as detailed in Chapter 2 of this thesis. However, due to the great number of experiments performed and the need to understand the influence of the factors, as temperature and atmosphere compositions, and the interactions between them on the coal combustion, the Design of Experiments (DoE) analysis is applied in the laboratory test facility, as developed in Chapter 3. The reactivity of low rank coals is assessed by means of global kinetic parameters and of char combustion reaction coefficients, under assumption of a well stirred reactor to be tested along the investigation, as described in Chapter 4. From the analysis of oxygen concentration curves (Chapter 2 and 3), results show that oxidizer oxy-fuel atmosphere with 79% CO2 (21/79, O2/CO2) increases the oxygen consumption for high ash coals, Bonito and Leão, and for pre-dried lignite coal, LTBK, due to the influence of CO2 gasification reaction on their coal combustion reactions from gas combustion temperatures higher than 1073 K. From the analysis of global kinetic parameters calculated to assess the coal reactivity, the results show that the hypothesis of a well stirred reactor is not enough to capture the kinetic involved in coal combustion burned in batch mode within the cyclone reactor. The coal reactivity investigated with the effective reaction rate constants for different oxidizer atmospheres, gas combustion temperatures, particle diameters, sample masses and oxygen sensor position, is influenced by the swirling flow with its advective and diffusive terms.
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Lichvár, Michal. "Detekce živosti prstu na základě změn papilárních linií." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2008. http://www.nusl.cz/ntk/nusl-236005.
Повний текст джерелаАнотація:
There are several frauds against biometric systems (BSs) and several techniques exist to secure BSs against these frauds. One of the techniques is liveness detection. To fool fingerprint sensors, latent fingerprints, dummy fingers and wafer-thin layer attached to the finger are being used. Liveness detection is being used also when scanning fingerprints. Several different characteristics of the live finger can be used to detect liveness, for example sweat, conductivity etc. In this thesis, new approach is examined. It is based on the expandability of the finger as an effect of heartbeats/pulsation. As the skin is expanding, also the distances between papillary lines are expanding. Whole finger expands approximately in range of 4,5 ľm , the distance between two neighbor papillary lines in 0,454 ľm . This value collides with wavelength of blue and green light. The result from this work is following. The resolution of the capturing device is not high enough to capture the expandability on distance between two neighbor papillary lines. Also, because of collision with wavelength, the diffraction effect is presented and the result images are influenced by this error.
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Francoforte, Kevin. "PARAMETER ESTIMATION USING SENSOR FUSION AND MODEL UPDATING." Master's thesis, University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4154.
Повний текст джерелаАнотація:
Engineers and infrastructure owners have to manage an aging civil infrastructure in the US. Engineers have the opportunity to analyze structures using finite element models (FEM), and often base their engineering decisions on the outcome of the results. Ultimately, the success of these decisions is directly related to the accuracy of the finite element model in representing the real-life structure. Improper assumptions in the model such as member properties or connections, can lead to inaccurate results. A major source of modeling error in many finite element models of existing structures is due to improper representation of the boundary conditions. In this study, it is aimed to integrate experimental and analytical concepts by means of parameter estimation, whereby the boundary condition parameters of a structure in question are determined. FEM updating is a commonly used method to determine the "as-is" condition of an existing structure. Experimental testing of the structure using static and/or dynamic measurements can be utilized to update the unknown parameters. Optimization programs are used to update the unknown parameters by minimizing the error between the analytical and experimental measurements. Through parameter estimation, unknown parameters of the structure such as stiffness, mass or support conditions can be estimated, or more appropriately, "updated", so that the updated model provides for a better representation of the actual conditions of the system. In this study, a densely instrumented laboratory test beam was used to carry-out both analytical and experimental analysis of multiple boundary condition setups. The test beam was instrumented with an array of displacement transducers, tiltmeters and accelerometers. Linear vertical springs represented the unknown boundary stiffness parameters in the numerical model of the beam. Nine different load cases were performed and static measurements were used to update the spring stiffness, while dynamic measurements and additional load cases were used to verify these updated parameters. Two different optimization programs were used to update the unknown parameters and then the results were compared. One optimization tool was developed by the author, Spreadsheet Parameter Estimation (SPE), which utilized the Solver function found in the widely available Microsoft Excel software. The other one, comprehensive MATLAB-based PARameter Identification System (PARIS) software, was developed at Tufts University. Optimization results from the two programs are presented and discussed for different boundary condition setups in this thesis. For this purpose, finite element models were updated using the static data and then these models were checked against dynamic measurements for model validation. Model parameter updating provides excellent insight into the behavior of different boundary conditions and their effect on the overall structural behavior of the system. Updated FEM using estimated parameters from both optimization software programs generally shows promising results when compared to the experimental data sets. Although the use of SPE is simple and generally straight-forward, we will see the apparent limitations when dealing with complex, non-linear support conditions. Due to the inherent error associated with experimental measurements and FEM modeling assumptions, PARIS serves as a better suited tool to perform parameter estimation. Results from SPE can be used for quick analysis of structures, and can serve as initial inputs for the more in depth PARIS models. A number of different sensor types and spatial resolution were also investigated for the possible minimum instrumentation to have an acceptable model representation in terms of model and experimental data correlation.M.S.
Department of Civil and Environmental Engineering
Engineering and Computer Science
Civil Engineering MS
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Jin, Xiaodan. "Poisson Approximation to Image Sensor Noise." University of Dayton / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1292306911.
Повний текст джерела
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Unver, Alper. "Determination Of Stochastic Model Parameters Of Inertial Sensors." Phd thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615548/index.pdf.
Повний текст джерелаАнотація:
ABSTRACT
DETERMINATION OF STOCHASTIC MODEL PARAMETERS OF INERTIAL SENSORS
Ünver, Alper PhD, Department of Electric Electronic Engineering Supervisor: Prof. Dr. Mü
beccel Demirekler January 2013, 82 pages Gyro and accelerometer systematic errors due to biases, scale factors, and misalignments can be compensated via an on-board Kalman filtering approach in a Navigation System. On the other hand, sensor random noise sources such as Quantization Noise (QN), Angular Random Walk (ARW), Flicker Noise (FN), and Rate Random Walk (RRW) are not easily estimated by an on-board filter, due to their random characteristics. In this thesis a new method based on the variance of difference sequences is proposed to compute the powers of the above mentioned noise sources. The method is capable of online or offline estimation of stochastic model parameters of the inertial sensors. Our aim in this study is the estimation of ARW, FN and RRW parameters besides the quantization and the Gauss-Markov noise parameters of the inertial sensors. The proposed method is tested both on the simulated and the real sensor data and the results are compared with the Allan variance method. Comparison shows very satisfactory results for the performance of the method. Computational load of the new method is less than the computational load of the Allan variance on the order of tens. One of the usages of this method is the individual noise characterization. A noise, whose power spectral density has a constant slope, can be identified accurately by the proposed method. In addition to this, the parameters of the GM noise can also be determined. Another idea developed here is to approximate the overall error source as a combination of ARW and some number of GM sources only. The reasons of selecting such a structure is the feasibility of using these models in a Kalman filter framework for error propagation as well as their generality of modeling other noise sources.
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Simoes, Mario Alves. "Feasibility of Wearable Sensors to Determine Gait Parameters." Scholar Commons, 2011. http://scholarcommons.usf.edu/etd/3346.
Повний текст джерелаАнотація:
A wearable system that can be used in different settings to collect gait parameters on subjects with a mild traumatic brain injury (mTBI) would allow clinicians to collect needed data of subjects outside of the laboratory setting. Mild traumatic brain injuries stem from a number of causes such as illnesses, strokes, accidents or battlefield traumas. These injuries can cause issues with everyday tasks, such as gait, and are linked with vestibular dysfunction [1]. Different wearable sensor systems were analyzed prior to starting this study along with relevant gait parameters associated with mild traumatic brain injury. To monitor gait parameters relevant to mild traumatic brain injury (cadence, torso rate of rotation, head rate of rotation and stride length) a wearable sensor system was selected (APDM Opal Movement Monitor [13]) and compared against the gold standard optical tracking system (Vicon) [2]. A group of ten, 20-27 year old, healthy subjects were used to validate the APDM Movement Monitor system using the Pearson's R correlation value [35]. Subjects were asked to wear the APDM movement monitors in conjunction with the reflective markers of the Vicon system while performing three sessions of gait trials: a normal gait speed, a fast gait speed and a slow gait speed. Using the Pearson's R correlation values, cadence, torso rate of rotation, and head rate of rotation were found to be highly correlated between both systems. The Pearson's R correlations for cadence, torso rate of rotation, head rate of rotation and stride length were 0.967, 0.907, 0.942, and 0.861, respectively. These correlation values suggest the gait parameters relevant to mild traumatic brain injury are highly correlated between both the APDM Movement Monitor system and the Vicon system, and APDM's wearable sensor system was lightweight, portable and less costly than the Vicon system.
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Yu, Jia. "Distributed parameter and state estimation for wireless sensor networks." Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/28929.
Повний текст джерелаАнотація:
The research in distributed algorithms is linked with the developments of statistical inference in wireless sensor networks (WSNs) applications. Typically, distributed approaches process the collected signals from networked sensor nodes. That is to say, the sensors receive local observations and transmit information between each other. Each sensor is capable of combining the collected information with its own observations to improve performance. In this thesis, we propose novel distributed methods for the inference applications using wireless sensor networks. In particular, the efficient algorithms which are not computationally intensive are investigated. Moreover, we present a number of novel algorithms for processing asynchronous network events and robust state estimation. In the first part of the thesis, a distributed adaptive algorithm based on the component-wise EM method for decentralized sensor networks is investigated. The distributed component-wise Expectation-Maximization (EM) algorithm has been designed for application in a Gaussian density estimation. The proposed algorithm operates a component-wise EM procedure for local parameter estimation and exploit an incremental strategy for network updating, which can provide an improved convergence rate. Numerical simulation results have illustrated the advantages of the proposed distributed component-wise EM algorithm for both well-separated and overlapped mixture densities. The distributed component-wise EM algorithm can outperform other EM-based distributed algorithms in estimating overlapping Gaussian mixtures. In the second part of the thesis, a diffusion based EM gradient algorithm for density estimation in asynchronous wireless sensor networks has been proposed. Specifically, based on the asynchronous adapt-then-combine diffusion strategy, a distributed EM gradient algorithm that can deal with asynchronous network events has been considered. The Bernoulli model has been exploited to approximate the asynchronous behaviour of the network. Compared with existing distributed EM based estimation methods using a consensus strategy, the proposed algorithm can provide more accurate estimates in the presence of asynchronous networks uncertainties, such as random link failures, random data arrival times, and turning on or off sensor nodes for energy conservation. Simulation experiments have been demonstrated that the proposed algorithm significantly outperforms the consensus based strategies in terms of Mean-Square- Deviation (MSD) performance in an asynchronous network setting. Finally, the challenge of distributed state estimation in power systems which requires low complexity and high stability in the presence of bad data for a large scale network is addressed. A gossip based quasi-Newton algorithm has been proposed for solving the power system state estimation problem. In particular, we have applied the quasi-Newton method for distributed state estimation under the gossip protocol. The proposed algorithm exploits the Broyden- Fletcher-Goldfarb-Shanno (BFGS) formula to approximate the Hessian matrix, thus avoiding the computation of inverse Hessian matrices for each control area. The simulation results for IEEE 14 bus system and a large scale 4200 bus system have shown that the distributed quasi-Newton scheme outperforms existing algorithms in terms of Mean-Square-Error (MSE) performance with bad data.
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Hoffman, Samuel Chase. "Automotive Suspension Parameter Estimation Using Smart Wireless Sensor Technology." DigitalCommons@CalPoly, 2008. https://digitalcommons.calpoly.edu/theses/20.
Повний текст джерелаАнотація:
This thesis project demonstrates the feasibility of using a smart sensor system to estimate vehicle parameters. It includes the development of the smart sensor system and the method for which vehicle parameters are estimated using this system. The smart sensor system is a wireless computer controlled sensor array that can be easily installed onto a vehicle. Parameter estimation was accomplished using grey box code in Matlab System Identification Toolbox, a software package from Mathworks. Front and rear suspension damping rates and pitch inertia were estimated on the 2008 Cal Poly SAE Baja Car with good accuracy during testing.
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Воробйов, Владислав Євгенійович. "Оптичні рідкокристалічні сенсори". Bachelor's thesis, КПІ ім. Ігоря Сікорського, 2020. https://ela.kpi.ua/handle/123456789/35117.
Повний текст джерелаАнотація:
Дипломна робота присвячена питанням підвищення ефективності одного з основних виконавчих елементів електроніки. Ознайомлення з основними характеристиками сесорів. Аналіз шляхів оптимізації технічних параметрів датчиків рідкокристалічного градієнта тиску. Аналіз рідких кристальних сензорів акселерації, вібрацій і включення.
У роботі розглянуто башато типів сенсорів та віддано перевашу оптичному рідкокристалічному сесору в зв’язку з легкою уніфікаціею його конструкції та широким використанням в побуті. Використовуючи властивості рідкокристалічних матеріалів вдалося досягти надзвичано чутливих ті презиційних сенсорів.Thesis is devoted to improving the efficiency of one of the main executive elements of electronics. Introduction to the main characteristics of sessors. Analysis of ways to optimize the technical parameters of liquid crystal pressure gradient sensors. Analysis of liquid crystal sensors of acceleration, vibration and inclusion. The paper considers many types of sensors and prefers the optical liquid crystal sensor due to the easy unification of its construction and widespread use in the home. Using the properties of liquid crystal materials, it was possible to achieve extremely sensitive sensing sensors.
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Liu, Mengmei. "Target Tracking with Binary Sensor Networks." UKnowledge, 2013. http://uknowledge.uky.edu/ece_etds/14.
Повний текст джерелаАнотація:
Binary Sensor Networks are widely used in target tracking and target parameter estimation. It is more computationally and financially efficient than surveillance camera systems. According to the sensing area, binary sensors are divided into disk shaped sensors and line segmented sensors. Different mathematical methods of target trajectory estimation and characterization are applied. In this thesis, we present a mathematical model of target tracking including parameter estimation (size, intrusion velocity, trajectory, etc.) with line segmented sensor networks. Software simulation and hardware experiments are built based on the model. And we further analyze how the quantization noise affects the results.
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Fraleigh, Lisa Marie. "Optimal sensor selection and parameter estimation for real-time optimization." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ40050.pdf.
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Hoffman, Samuel Chase Ridgely John Robert. "Automotive suspension parameter estimation using smart wireless sensor technology : a thesis /." [San Luis Obispo, Calif. : California Polytechnic State University], 2008. http://digitalcommons.calpoly.edu/theses/20/.
Повний текст джерелаАнотація:
Thesis (M.S.)--California Polytechnic State University, 2008."May 2008." "In partial fulfillment of the requirements for the degree [of] Master of Science in Mechanical Engineering." "Presented to the faculty of California Polytechnic State University, San Luis Obispo." Major professor: John Ridgely, Ph.D. Accompanying CD-ROMs contain software files. Includes bibliographical references (leaf 61). Also available online and on microfiche (2 sheets).
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Gunnam, Kiran Kumar. "A DSP embedded optical naviagtion system." Thesis, Texas A&M University, 2003. http://hdl.handle.net/1969/13.
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Johansson, Tobias. "Virtual Sensors for Combustion Parameters Based on In-Cylinder Pressure." Thesis, Linköpings universitet, Fordonssystem, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-123490.
Повний текст джерелаАнотація:
Typically the combustion in engines are open-loop controlled. By using an in-cylinder pressure sensor it is possible to create virtual sensors for closed-loop combustion control (CLCC). With CLCC it is possible to counteract dynamic effects as component ageing, fuel type and cylinder variance. A virtual sensor system was implemented based on a one-zone heat-release analysis, including signal processing of the pressure sensor input. A parametrisation of the heat-release based on several Vibe functions was implemented with good results. The major focus of the virtual sensor system was to perform a tolerance analysis on experimental data, where typical error sources in a production heavy-duty vehicle were identified and their effect on the estimates quantified. It could be concluded that estimates are very much dependent on the choice of heat-release and specific heat ratio models. Especially crank angle phasing has a large impact on estimation performance, stressing the importance of accounting for crankshaft torsion in production vehicles. Biodiesel advances the combustion angle and give a lower IMEP and total heat amount compared to standard diesel. However, error sensitivity is not affected. Further investigations must be made on improving the signal processing in terms of gain error compensation and filtering. Also a better understanding of how errors propagate between subsystems in a CLCC system is required for successful implementation.
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Dasgupta, Kaushani. "Parameter Estimation Using Consensus Building Strategies with Application to Sensor Networks." Thesis, University of North Texas, 2013. https://digital.library.unt.edu/ark:/67531/metadc407815/.
Повний текст джерелаАнотація:
Sensor network plays a significant role in determining the performance of network inference tasks. A wireless sensor network with a large number of sensor nodes can be used as an effective tool for gathering data in various situations. One of the major issues in WSN is developing an efficient protocol which has a significant impact on the convergence of the network. Parameter estimation is one of the most important applications of sensor network. In order to model such large and complex networks for estimation, efficient strategies and algorithms which take less time to converge are being developed. To deal with this challenge, an approach of having multilayer network structure to estimate parameter and reach convergence in less time is estimated by comparing it with known gossip distributed algorithm. Approached Multicast multilayer algorithm on a network structure of Gaussian mixture model with two components to estimate parameters were compared and simulated with gossip algorithm. Both the algorithms were compared based on the number of iterations the algorithms took to reach convergence by using Expectation Maximization Algorithm.Finally a series of theoretical and practical results that explicitly showed that Multicast works better than gossip in large and complex networks for estimation in consensus building strategies.
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YU, JINSONG. "Development of Microfabricated Electrochemical Sensors for Environmental Parameter Measurements Applicable to Corrosion Evaluation and Gaseous Oxygen Detection." Case Western Reserve University School of Graduate Studies / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=case1206981091.
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Fletcher, R. P. "Statistical inversion of surface parameters from ATSR-2 satellite observations." Thesis, University of Reading, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267415.
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Kristensson, Martin. "On parameter estimation in wireless communications, sensor array processing and spectral analysis." Doctoral thesis, Stockholm, 1998. http://www.lib.kth.se/abs98/kris1216.pdf.
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Reina, Gerard J. "AUV dive control system development including sensor bias compensation and parameter estimation." Thesis, Monterey, California. Naval Postgraduate School, 1988. http://hdl.handle.net/10945/22925.
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Approved for public release; distribution is unlimited.The U.S. Navy and a number of its contractors are presently developing unmanned miniature submarines for several vital underwater missions. These include surveillance, submarine tracking, and bottom mapping. Foregoing Research at NPS produced a "testbed" as a research platform for demonstrating the performance of AUVs. Combining the power of an IBM PC/AT in conjunction with a high level programming language, a state space dive control system was developed and instituted for the 30 inch AUV model. Paramter Estimation using a Recursive Least Squares Fit scheme and a State Observer were incorporated in the controller. Procedures dealing with hardware/software interfacing, AUV simulation analysis, and computation speed of large programming code were investigated.
http://archive.org/details/auvdivecontrolsy00rein
Lieutenant, United States Navy
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Moustafa, Ahmed. "Deducing water parameters in rivers via statistical modelling." Thesis, Loughborough University, 2011. https://dspace.lboro.ac.uk/2134/9095.
Повний текст джерелаАнотація:
Advanced monitoring of water quality in order to perform a real-time hazard analysis prior to Water Treatment Works (WTW) is more of a necessity nowadays, both to give warning of any contamination and also to avoid downtime of the WTW. Downtimes could be a major contributor to risk. Any serious accident will cause a significant loss in customer and investor confidence. This has challenged the industry to become more efficient, integrated and attractive, with benefits for its workforce and society as a whole. The reality is that water companies are not yet prepared to invest heavily in trials, before another company announces its success in implementing a new monitoring strategy. This has slowed down the development of the water industry. This research has taken the theoretical idea that the use of advanced online monitoring technique in the water industry would be beneficial and a step further; demonstrating by means of a state-of-the-art assessment, usability trials, case studies and demonstration that the barriers to mainstream adoption can be overcome. The findings of this work have been presented in four peer-reviewed papers. The research undertaken has shown that Turbidity levels in rivers can be measured from the rivers' mean flow rate, using either Doppler Ultrasound device for real-time readings or based on past performance history. In both cases, the Turbidity level can also help estimate both the Colour and Conductivity levels of the subject river. Recalibration of the equations used is a prerequisite as each individual river has its own unique "finger print".
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Sallinen, Mikko. "Modelling and estimation of spatial relationships in sensor-based robot workcells /." Espoo [Finland] : VTT Technical Research Centre of Finland, 2003. http://www.vtt.fi/inf/pdf/publications/2003/P509.pdf.
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Feng, Chao. "GREY-MODEL BASED ICE PREDICTION SENSOR SYSTEM ON WIND TURBINE SYSTEM." Case Western Reserve University School of Graduate Studies / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=case1323893527.
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Mamishev, Alexander V. 1974. "Interdigital dielectrometry sensor design and parameter estimation algorithms for non-destructive materials evaluation." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/16729.
Повний текст джерелаАнотація:
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.Vita.
Includes bibliographical references (v. 2, p. 677-704).
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
The major objective of this thesis is to develop instrumentation and parameter estimation algorithms for nondestructive measurement of non-homogeneous material property profiles with fringing electric field dielectrometry sensors. The instrumentation includes interdigital sensors and sensor arrays, other types of fringing field sensors, electronic circuit boards for measurement of sensor signals, and mechanical setups for specific applications. The parameter estimation algorithms require solving forward and inverse problems of material property estimation. The forward problem implies calculation of the sensor admittance matrix as a function of geometry and material properties. The inverse problem, inherently more difficult than the forward problem, implies estimation of unknown geometry and material properties based on known properties and measured entries of the sensor admittance matrix. The developed instrumentation and algorithms are applied to practical problems which include mo++
nitoring of moisture dynamics in transformer pressboard, evaluation of the saturation state of chemical garments, detection of flaws in fiberglass flywheels, and detection of buried metal and plastic landmines. The design strategy and fabrication practices are described for multiple penetration depth interdigital sensors designed for measurement of conductivity and permittivity of electrical insulation of power transformers. An extensive overview of interdigital electrode technology in other fields is given. A number of disturbance parameters that affect interdigital dielectrometry measurements is characterized and either eliminated or accounted for using empirical, analytical, and numerical simulation approaches. A new type of fringing field sensor has been developed to improve the cross-correlation between different fringing field patterns. In most cases, the forward problem has been solved using commercial finite-element software "Maxwell" by Ansoft Corp. Other methods, such as a co++
ntinuum model, analytical expressions, and direct calibration were used for comparison and to achieve greater accuracy in simple cases. A family of algorithms for solving inverse problems has been developed to address different applications.
(cont.) No single algorithm provides the most accurate and reliable results in all cases. The most appropriate algorithm for each given application should be chosen on the basis of required speed and accuracy, number of known and unknown parameters, type of distribution of material properties, contact conditions between the sensor head and the material, and a specific type of sensor selected for the task. Major types of property estimation algorithms include direct calibration; use of empirically and numerically determined approximations; use of pre-computed lookup tables; iterative guesses at dielectric and geometry properties while solving the minimization problem of matching theoretical and measured entries of sensor admittance matrix; direct mapping between the sensor output and the physical variable of interest (not necessarily a dielectric property);
(cont.) pattern recognition in the dielectric spectroscopy signature; and search for signal characteristics in the sensor output due to material property variations. Each of these major types of algorithms has been implemented in one or more forms to achieve the desired results for each specific problem. One of the algorithmic approaches has been generalized to other types of problemsby implementing it as a generic optimization tool. Moisture dynamics in transformer pressboard has been studied extensively with numerical simulations of the forward and inverse problem. The developed algorithm has been applied to experimental dataobtained by another graduate student, Yanqing Du, in a concurrent Ph.D. thesis. It has been demonstrated that a three-wavelength interdigital sensor can be used to measure time-dependent continuous smoothly varying moisture profiles in oil-impregnated power transformer pressboard. Ultimately, this technology is capable of preventing partial discharges and transformer failures due to flow electrification and static charging of the oil-pressboard interface. Preliminary measurements also demonstrated adequate sensitivity and selectivity of fringing field sensors for the detection of flaws in fiberglass flywheels and detection and discrimination of buried plastic and metal landmines. The saturation state of chemical protective garments hasbeen determined for relatively high levels of saturation. Additional work is needed to improve sensitivity in the low saturation region.
by Alexander V. Mamishev.
Ph.D.
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Lee, Shira M. (Shira Miriam). "Finite element simulation and parameter optimization of a flexible tactile pressure sensor array." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/32948.
Повний текст джерелаАнотація:
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2005.Includes bibliographical references.
A finite element model was developed to optimize design of a flexible tactile sensor. The sensor consists of layers of thin-film copper and PDMS, and the model can be used to determine the effects on sensor sensitivity and durability of variations in material properties and geometry. The model was used to study the effect of variations in copper thickness. Four copper thicknesses, 0.3[mu]m, 0.5[mu]m, 3[mu]m, and 9[mu]m, were analyzed under a range of pressure loads. The thickness of the copper affected both the stress in the material and the displacement of the copper when a pressure load was applied to the sensor model. The stress in the sensor was highest for 3[mu]m copper, potentially causing decreased durability in this sensor. The separation between the copper strips beneath the pressure load was highest for 9[mu]m copper, so this sensor may have lower accuracy for small loads. Thin copper strips are challenging to manufacture, so the largest but most accurate and durable copper strip thickness, 0.5[mu]m, is recommended from this analysis.
by Shira M. Lee.
S.B.
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Furness, Charles Zachary. "Parameter identification of a flexible beam using a modal domain optical fiber sensor." Thesis, Virginia Tech, 1990. http://hdl.handle.net/10919/42058.
Повний текст джерелаАнотація:
An optical fiber sensor is used for identification of a cantilevered beam under conditions of various concentrated mass loadings. A model of the sensor as well as the dynamic system is developed and used to test the reliability of the identification. Input/output data from an experiment is gathered and used in the identification. A survey of the existing areas of damage detection and parameter identification is included, along with suggestions for incorporating fiber optic sensors into existing techniques. The goal of this research was to show that the fiber sensor can be used for identification purposes, and that it is sensitive to parameter changes within the system (in this case concentrated mass changes).
Master of Science