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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
171

Nezávislý datalogger s USB připojením / Autonomous USB datalogger

Románek, Karel January 2010 (has links)
This thesis treats concept of autonomous temperature, relative humidity and pressure USB datalogger. Also there is explained datalogger function, hardware design with respect on device consumption and design of chassis. Furthermore, there is described communication protocol for control and reading out data by the PC. Furthermore, there are described firmware drivers for some used components and modules for USB communication, RTC and data compression. Lastly there is described software which is used for datalogger configuration and data read out.
172

Metody pro zpracování termovizních snímků s detekcí stanovené oblasti obličeje / Methods for infrared thermography with detection of specific facial areas

Kolářová, Dana January 2014 (has links)
This paper deals with non-contact measurement of temperature in human faces. Principle of measurement of infrared radiation and construction of the thermal imager is described in a literature search. The main part of the paper is design of an algorithm for automatic processing and the detection of regions of interest in thermal images. The theoretical description of used methods is also included in this paper. The aim is to design and implement a program for automatic evaluation of temperature changes in a human face in a sequence of thermal images that were taken with short time delay. As a part of thesis is description of implementation of designed algorithm in programming enviroment MATLAB and the description of the user interface. The program was tested on the experimental data samples. Obtained results and possible limitations are also discused in this paper.
173

Modelování tepelných procesů letecké elektroniky a problematika jejího chlazení / Thermal phenomena modeling of air electronic unit

Ančík, Zdeněk January 2010 (has links)
This thesis is focus on thermal analysis of aircraft electronic devices and their cooling possibilities. The two analytic methods of thermal analysis are applied on two particular technical objects. The laboratory experiment of non-contact temperature measurement method is applied on real unit. The results of simulation are compared with results of experiment.
174

Full-Field Measurement of the Taylor-Quinney Coefficient in Tension Tests of Ti-6Al-4V, Aluminum 2024-T351, and Inconel 718 at Various Strain Rates

Smith, Jarrod L. 08 July 2019 (has links)
No description available.
175

Monitoring of microclimate underneath agrivoltaic systems using IoT sensor station

Stridsman, Erik January 2023 (has links)
Agrivoltaic systems work on the principle of combining farmland with Photovoltaic energy conversion giving the land it sits on dual purpose. Moreover, by combining solar electricity conversion and crop production additional benefits such as water saving and, in some cases even higher crop yields compared to open field conditions. For this technology to be wildly implemented a deeper understanding on the effects the agrivoltaic system has on the underlying farmland is required. In this work, an IoT sensor station used for monitoring albedo, temperature, and humidity inside an agrivoltaic system is developed. The work is carried out through researching and testing electrical components that is to be used inside of the monitoring station as well as development of the code used by the microcontroller to communicate between the different sensors. The prototype station was then tested a total of three times at Kärrbo Prästgård and the gathered data compared with pre-installed sensors located at the testing site. After each test run the IoT stations performance was analyzed for potential improvements to be implemented before subsequent tests. The final design of monitoring station showed a high accuracy in the albedo data during daytime with some deviations during early mornings and late afternoon due to the inherit limitations in the sensitivities of the electrical components used to measure solar radiation.
176

DEVELOPMENT OF A MOLECULAR RAYLEIGH SCATTERING DIAGNOSTIC FOR SIMULTANEOUS TIME-RESOLVED MEASUREMENT OF TEMPERATURE, VELOCITY, AND DENSITY

Mielke, Amy Florence January 2008 (has links)
No description available.
177

Contribution à l'étude de la transition décharge luminescente / arc électrique dans l'air et dans l'argon au voisinage de la pression atmosphérique. / Contribution to the study of the transition between glow discharges and electric arcs in air and in argon near atmospheric pressure

Landfried, Romaric 06 December 2011 (has links)
Dans ce travail, nous proposons une approche essentiellement expérimentale. Dans une première partie, nous exposons les résultats obtenus par imagerie rapide et mesures électriques corrélées dans le temps, concernant l’étude de la transition entre des électrodes de cuivre dans l’air et l’argon, et entre des électrodes de tungstène dans l’argon pour des pressions comprises entre 100 mbar et 1 bar. Dans aucun cas une transition à l’arc n’est observée sans constriction quasi-totale de la colonne positive. Dans le cas d’électrodes en tungstène dans l’argon, la vitesse d’extension de la zone filamentaire depuis l’anode vers la cathode a été vue dépendante de la pression et de l’intensité. La durée d’une transition spontanée a été linéairement corrélée à la distance inter-électrode, suggérant un mécanisme propagatif à vitesse constante dans la colonne. Plus la pression est élevée, plus la durée totale des transitions est longue ; par ailleurs, à pression constante, cette durée de transition spontanée décroît à intensité croissante, pour tendre vers une durée limite, correspondant à la durée constante de changement de structure de la zone cathodique. Dans une seconde partie, nous nous intéressons à l’échauffement de surfaces d’anodes et de cathodes en cuivre dans l’air et dans l’argon soumises à des arcs électrique pour plusieurs gammes de courant (de 30 à 120 A). Deux méthodes de mesures sont utilisées. Enfin, nous utilisons les mesures de températures de surface pour proposer deux modèles simples de bilan de puissance à la surface des électrodes (flux de chaleur). L’un considère uniquement le chauffage dû au spot d’arc et l’autre le chauffage supplémentaire de la colonne d’arc. / In this work, an approach which is essentially experimental is proposed. In the first part, results are presented which were obtained by synchronized fast camera imaging and electrical measurements. These concern the study of the transition between copper electrodes in air and in argon, and between tungsten electrodes in argon for gas pressure in the range 100 mbar – 1 bar. In no case was the transition to arc been observed without the quasi-total constriction of the positive column. Considering tungsten electrodes in argon, the propagation speed of the filamentary part of the positive column from the anode to the cathode was found to be dependent on the gas pressure and the discharge current intensity. During spontaneous transition, the transition duration has been linearly correlated to the electrode gap, suggesting a propagative mechanism with a constant speed. The higher the pressure, the longer is the total transition duration. For a constant pressure and discharge current, the duration of spontaneous transition decreases with decreasing gap distance toward a limiting value, which corresponds to the constant duration of the structural change of the cathode root from diffuse to spot. In the second part, heating of copper anodes and copper cathodes submitted to electric arcs in air and in argon and for various current intensity values (from 30A to 120 A) is considered. Two measurement methods are used. Finally, the surface temperature measurements are used to purpose two models of the electrode surface power balance (heat flux). One model only considers the heating due to the arc spot and the second one considers a supplementary heating from the arc column.
178

Monitoração e diagnóstico para detecção de falhas de sensores utilizando a metodologia GMDH / Monitoring and diagnosis for sensor fault detection using GMDH methodology

Gonçalves, Iraci Martinez Pereira 16 February 2006 (has links)
O sistema de detecção de falhas e diagnóstico é um sistema de suporte ao operador dedicado a funções específicas que alertam os operadores para problemas de falhas em sensores e atuadores, e auxiliam no diagnóstico antes que os limites normais de alarmes sejam atingidos. Sistemas de suporte ao operador surgiram para diminuir a complexidade dos painéis causada pelo grande aumento de informação disponível nas salas de controle das centrais nucleares. Neste trabalho foi desenvolvido um Sistema de Monitoração e Diagnóstico utilizando a metodologia GMDH (Group Method of Data Handling) aplicado ao reator de pesquisas do Ipen IEA-R1. O sistema faz a monitoração, comparando os valores calculados pelo modelo GMDH com os valores medidos. A metodologia desenvolvida foi aplicada inicialmente em modelos teóricos: um modelo teórico de trocador de calor e um modelo teórico do reator IEA-R1. Os resultados obtidos com os modelos teóricos propiciaram uma base para a aplicação da metodologia aos dados de operação do reator. Para a monitoração de dados de operação foram desenvolvidos três modelos GMDH: o primeiro utilizou apenas variáveis de processo, o segundo modelo foi desenvolvido considerando-se algumas variáveis nucleares e três variáveis de temperatura, e o terceiro modelo GMDH considerou todas as variáveis possíveis. Os três modelos apresentaram resultados excelentes, mostrando amplamente a viabilidade da utilização da metodologia GMDH na monitoração de dados de operação. A comparação entre os resultados dos três modelos desenvolvidos mostrou ainda a capacidade da metodologia GMDH de escolher as melhores variáveis para otimização do modelo. Para a implementação de um sistema de diagnóstico, foram adicionadas falhas sinteticamente aos valores das variáveis de temperatura. Os valores de falhas correspondem a uma descalibração da temperatura e o resultado da monitoração de dados com falhas foi utilizado para a elaboração de um sistema de diagnóstico simples e objetivo baseado na lógica nebulosa. / The fault detection and diagnosis system is an Operator Support System dedicated to specific functions that alerts operators to sensors and actuators fault problems, and guide them in the diagnosis before the normal alarm limits are reached. Operator Support Systems appears to reduce panels complexity caused by the increase of the available information in nuclear power plants control room. In this work a Monitoring and Diagnosis System was developed based on the GMDH (Group Method of Data Handling) methodology. The methodology was applied to the IPEN research reactor IEA-R1. The system performs the monitoring, comparing GMDH model calculated values with measured values. The methodology developed was firstly applied in theoretical models: a heat exchanger model and an IPEN reactor theoretical model. The results obtained with theoretical models gave a base to methodology application to the actual reactor operation data. Three GMDH models were developed for actual operation data monitoring: the first one using just the thermal process variables, the second one was developed considering also some nuclear variables, and the third GMDH model considered all the reactor variables. The three models presented excellent results, showing the methodology utilization viability in monitoring the operation data. The comparison between the three developed models results also shows the methodology capacity to choose by itself the best set of input variables for the model optimization. For the system diagnosis implementation, faults were simulated in the actual temperature variable values by adding a step change. The fault values correspond to a typical temperature descalibration and the result of monitoring faulty data was then used to build a simple diagnosis system based on fuzzy logic.
179

Monitoração e diagnóstico para detecção de falhas de sensores utilizando a metodologia GMDH / Monitoring and diagnosis for sensor fault detection using GMDH methodology

Iraci Martinez Pereira Gonçalves 16 February 2006 (has links)
O sistema de detecção de falhas e diagnóstico é um sistema de suporte ao operador dedicado a funções específicas que alertam os operadores para problemas de falhas em sensores e atuadores, e auxiliam no diagnóstico antes que os limites normais de alarmes sejam atingidos. Sistemas de suporte ao operador surgiram para diminuir a complexidade dos painéis causada pelo grande aumento de informação disponível nas salas de controle das centrais nucleares. Neste trabalho foi desenvolvido um Sistema de Monitoração e Diagnóstico utilizando a metodologia GMDH (Group Method of Data Handling) aplicado ao reator de pesquisas do Ipen IEA-R1. O sistema faz a monitoração, comparando os valores calculados pelo modelo GMDH com os valores medidos. A metodologia desenvolvida foi aplicada inicialmente em modelos teóricos: um modelo teórico de trocador de calor e um modelo teórico do reator IEA-R1. Os resultados obtidos com os modelos teóricos propiciaram uma base para a aplicação da metodologia aos dados de operação do reator. Para a monitoração de dados de operação foram desenvolvidos três modelos GMDH: o primeiro utilizou apenas variáveis de processo, o segundo modelo foi desenvolvido considerando-se algumas variáveis nucleares e três variáveis de temperatura, e o terceiro modelo GMDH considerou todas as variáveis possíveis. Os três modelos apresentaram resultados excelentes, mostrando amplamente a viabilidade da utilização da metodologia GMDH na monitoração de dados de operação. A comparação entre os resultados dos três modelos desenvolvidos mostrou ainda a capacidade da metodologia GMDH de escolher as melhores variáveis para otimização do modelo. Para a implementação de um sistema de diagnóstico, foram adicionadas falhas sinteticamente aos valores das variáveis de temperatura. Os valores de falhas correspondem a uma descalibração da temperatura e o resultado da monitoração de dados com falhas foi utilizado para a elaboração de um sistema de diagnóstico simples e objetivo baseado na lógica nebulosa. / The fault detection and diagnosis system is an Operator Support System dedicated to specific functions that alerts operators to sensors and actuators fault problems, and guide them in the diagnosis before the normal alarm limits are reached. Operator Support Systems appears to reduce panels complexity caused by the increase of the available information in nuclear power plants control room. In this work a Monitoring and Diagnosis System was developed based on the GMDH (Group Method of Data Handling) methodology. The methodology was applied to the IPEN research reactor IEA-R1. The system performs the monitoring, comparing GMDH model calculated values with measured values. The methodology developed was firstly applied in theoretical models: a heat exchanger model and an IPEN reactor theoretical model. The results obtained with theoretical models gave a base to methodology application to the actual reactor operation data. Three GMDH models were developed for actual operation data monitoring: the first one using just the thermal process variables, the second one was developed considering also some nuclear variables, and the third GMDH model considered all the reactor variables. The three models presented excellent results, showing the methodology utilization viability in monitoring the operation data. The comparison between the three developed models results also shows the methodology capacity to choose by itself the best set of input variables for the model optimization. For the system diagnosis implementation, faults were simulated in the actual temperature variable values by adding a step change. The fault values correspond to a typical temperature descalibration and the result of monitoring faulty data was then used to build a simple diagnosis system based on fuzzy logic.
180

Monitoração e diagnóstico para detecção de falhas de sensores utilizando a metodologia GMDH

GONCALVES, IRACI M. P. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:51:19Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:37Z (GMT). No. of bitstreams: 0 / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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