Dissertations / Theses on the topic 'Rain detection'
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Webster, Dereck D. "Automatic Rain Drop Detection for Improved Sensing in Automotive Computer Vision Applications." Thesis, Cranfield University, 2014. http://dspace.lib.cranfield.ac.uk/handle/1826/9154.
Full textKöylüoglu, Tugay, and Lukas Hennicks. "Evaluating rain removal image processing solutions for fast and accurate object detection." Thesis, KTH, Mekatronik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-254446.
Full textAutonoma fordon är för privat samt offentlig sektor ett viktigt område i modern forskning. Osäkerheten med autonoma fordon är en viktig anledning till varför de idag inte nått konsumentmarknaden. Systemen för autonoma fordon blir mer robusta med inkludering av flera sensorer av olika typer, vilka oftast är kameror, radar och lidars. Fordon med dessa sensorer kan snabbt öka i pris vilket gör dem mindre tillgängliga för olika marknader. Detta skulle kunna lösas med färre sensorer som däremot är mer robusta. Denna avhandling diskuterar problemet med en specific felmodell för kameror, vilket är minskat synfält som påverkas av regnigt väder. Kalman filter och diskret vågkomponent-transformation med bilateral filtrering utvärderades som regnborttagningsalgoritmer och testades med You Only Look Once (YOLOv3), en modern objektigenkänningsmetod. Filtrerade videofilmer i dagstid och kvällstid testades med YOLOv3 och resultaten visade att noggrannheten inte ökade tillräckligt mycket för att vara användbara för autonoma fordon. Med grafikkorten tillgängliga för denna avhandling är inte YOLOv3 snabb nog för ett fordon att hinna stanna i tid före kollision om bilen kör i 110km/h och ett föremål dyker upp 80m framför. Däremot antas det att fordon utrustade med Nvidias Titan X borde hinna stanna i tid före kollision. Avhandlingen ser däremot potential inom detta forskningsområde och föreslår att liknande test fast med andra objektigenkänningsmetoder bör utföras.
Ferroudj, Meriem. "Detection of rain in acoustic recordings of the environment using machine learning techniques." Thesis, Queensland University of Technology, 2015. https://eprints.qut.edu.au/82848/1/Meriem_Ferroudj_Thesis.pdf.
Full textMa, Bin-Bing. "Passive acoustic detection and measurement of rainfall at sea and an empirical ocean ambient sound model /." Thesis, Connect to this title online; UW restricted, 2004. http://hdl.handle.net/1773/11045.
Full textAllen, Jeffrey R. "An Analysis of SeaWinds Simultaneous Wind/Rain Retrieval in Severe Weather Events." Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd704.pdf.
Full textMarinaro, Ralph Michael. "Investigation of water vapor effects on the detection of nitric acid vapor with the tungstic acid technique." Diss., Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/71262.
Full textPh. D.
Liu, Zhongxun. "Modélisation des signatures radar des tourbillons de sillage par temps de pluie." Thesis, Toulouse, ISAE, 2013. http://www.theses.fr/2013ESAE0015/document.
Full textNvestigation on radar monitoring of wake vortices in rainy weather is of both scientific and practical interests. This topic hasbeen tackled through three successive steps during this thesis.Firstly, the motion of raindrops in wake vortices has been modeled and simulated. The equation of the motion has been derived and the methodology to compute the raindrops' trajectory and distribution in the flow induced by the wakevortices has been proposed. Secondly, two simulators have been developed for evaluating the radar signatures of raindropsin wake vortices. Those simulators have been used to reproduce experimental configurations and the comparison betweenmeasured and simulated signature has shown an interesting agreement at X and W band. Lastly, the interpretation of radarsignatures of raindrops in wake vortices has been presented. The dependence of radar signatures on rain rate, vortexcirculation and radar parameters has been studied. A wake vortex detection method based on the analysis of Dopplerspectrum width of raindrops and a methodology to estimate the wake vortex characteristics have been proposed.The radar signatures of wake vortices in rainy weather have been modeled and analyzed in this thesis. The simulationresults have demonstrated the capability of radar to detect wake vortex in rainy weather. The methodologies developed inthis thesis can be further exploited for designing new wake vortex radar systems
Sengupta, Nina. "Detection and prediction of biodiversity patterns as a rapid assessment tool in the tropical forest of East Usambara, Eastern Arc Mountains, Tanzania." Diss., Virginia Tech, 2003. http://hdl.handle.net/10919/30272.
Full textPh. D.
Friberg, Carol Diane. "Preliminary processing and evaluation of radar measurements in satellite-path propagation research." Thesis, Virginia Tech, 1985. http://hdl.handle.net/10919/45722.
Full textMaster of Science
Tang, Shengjie. "Rail Platform Obstacle Detection Using LabVIEW Simulation." Thesis, Högskolan i Gävle, Avdelningen för elektronik, matematik och naturvetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-19063.
Full textBhaduri, Sreyoshi. "Algorithm to enable intelligent rail break detection." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/78080.
Full textMaster of Science
Shrestha, Survesh Bahadur. "Defect Detection on Rail Base Area Using Infrared Thermography." OpenSIUC, 2020. https://opensiuc.lib.siu.edu/theses/2758.
Full textHopkins, Brad Michael. "A Wavelet-Based Rail Surface Defect Prediction and Detection Algorithm." Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/77351.
Full textPh. D.
Duthon, Pierre. "Descripteurs d'images pour les systèmes de vision routiers en situations atmosphériques dégradées et caractérisation des hydrométéores." Thesis, Université Clermont Auvergne (2017-2020), 2017. http://www.theses.fr/2017CLFAC065/document.
Full textComputer vision systems are increasingly being used on roads. They can be installed along infrastructure for traffic monitoring purposes. When mounted in vehicles, they perform driver assistance functions. In both cases, computer vision systems enhance road safety and streamline travel.A literature review starts by retracing the introduction and rollout of computer vision algorithms in road environments, and goes on to demonstrate the importance of image descriptors in the processing chains implemented in such algorithms. It continues with a review of image descriptors from a novel approach, considering them in parallel with final applications, which opens up numerous analytical angles. Finally the literature review makes it possible to assess which descriptors are the most representative in road environments.Several databases containing images and associated meteorological data (e.g. rain, fog) are then presented. These databases are completely original because image acquisition and weather condition measurement are at the same location and the same time. Moreover, calibrated meteorological sensors are used. Each database contains different scenes (e.g. black and white target, pedestrian) and different kind of weather (i.e. rain, fog, daytime, night-time). Databases contain digitally simulated, artificial and natural weather conditions.Seven of the most representative image descriptors in road context are then selected and their robustness in rainy conditions is evaluated. Image descriptors based on pixel intensity and those that use vertical edges are sensitive to rainy conditions. Conversely, the Harris feature and features that combine different edge orientations remain robust for rainfall rates ranging in 0 – 30 mm/h. The robustness of image features in rainy conditions decreases as the rainfall rate increases. Finally, the image descriptors most sensitive to rain have potential for use in a camera-based rain classification application.The image descriptor behaviour in adverse weather conditions is not necessarily related to the associated final function one. Thus, two pedestrian detectors were assessed in degraded weather conditions (rain, fog, daytime, night-time). Night-time and fog are the conditions that have the greatest impact on pedestrian detection. The methodology developed and associated database could be reused to assess others final functions (e.g. vehicle detection, traffic sign detection).In road environments, real-time knowledge of local weather conditions is an essential prerequisite for addressing the twin challenges of enhancing road safety and streamlining travel. Currently, the only mean of quantifying weather conditions along a road network requires the installation of meteorological stations. Such stations are costly and must be maintained; however, large numbers of cameras are already installed on the roadside. A new method that uses road traffic cameras to detect weather conditions has therefore been proposed. This method uses a combination of a neural network and image descriptors applied to image patches. It addresses a clearly defined set of constraints relating to the ability to operate in real-time and to classify the full spectrum of meteorological conditions and grades them according to their intensity. The method differentiates between normal daytime, rain, fog and normal night-time weather conditions. After several optimisation steps, the proposed method obtains better results than the ones reported in the literature for comparable algorithms
Nouri, Arash. "Correlation-Based Detection and Classification of Rail Wheel Defects using Air-coupled Ultrasonic Acoustic Emissions." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/78139.
Full textMaster of Science
Rani, Dipti [Verfasser]. "Label-free detection of biomolecules using silicon nanowire ion-sensitive field-effect transistor devices / Dipti Rani." Gießen : Universitätsbibliothek, 2018. http://d-nb.info/1156851343/34.
Full textSingh, Dejah Leandra. "The Application of Laser Technology for Railroad Top of Rail (TOR) Friction Modifier Detection and Measurements." Thesis, Virginia Tech, 2018. http://hdl.handle.net/10919/83234.
Full textMaster of Science
Halmaoui, Houssam. "Restauration d'images par temps de brouillard et de pluie : applications aux aides à la conduite." Phd thesis, Université d'Evry-Val d'Essonne, 2012. http://tel.archives-ouvertes.fr/tel-00830869.
Full textJehangiri, Ali Imran Verfasser], Ramin [Akademischer Betreuer] Yahyapour, Andrei [Akademischer Betreuer] [Tchernykh, Carsten [Akademischer Betreuer] Damm, Xiaoming [Akademischer Betreuer] Fu, Dieter [Akademischer Betreuer] Hogrefe, and Winfried [Akademischer Betreuer] Kurth. "Distributed Anomaly Detection and Prevention for Virtual Platforms / Ali Imran Jehangiri. Gutachter: Ramin Yahyapour ; Andrei Tchernykh ; Carsten Damm ; Xiaoming Fu ; Dieter Hogrefe ; Winfried Kurth. Betreuer: Ramin Yahyapour." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2015. http://d-nb.info/107475848X/34.
Full textGulán, Filip. "Detekce, lokalizace a určení plochy chronických ran." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2018. http://www.nusl.cz/ntk/nusl-385966.
Full textGiard, Martin. "Mesure de l'emission diffuse galactique dans la raie a 3,3 micrometre avec l'experience ballon arome." Toulouse 3, 1988. http://www.theses.fr/1988TOU30143.
Full textNorris, Natasha Louise. "Implementation of Multi-Constellation Baseline Fault Detection and Exclusion Algorithm Utilizing GPS and GLONASS Signals." Ohio University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1535028817622931.
Full textSchwarz, Brandon A. (Brandon Alexander). "Evaluation of a methodology for detecting railroad track geometry anomalies and determining rail vehicle fatigue loads." Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/12401.
Full textAydos, Gökçe [Verfasser], Görschwin [Akademischer Betreuer] [Gutachter] Fey, and Jaan [Gutachter] Raik. "Parity-based Error Detection with Recomputation for Fault-tolerant Spaceborne Computing / Gökçe Aydos ; Gutachter: Görschwin Fey, Jaan Raik ; Betreuer: Görschwin Fey." Bremen : Staats- und Universitätsbibliothek Bremen, 2017. http://d-nb.info/1140581732/34.
Full textNallaivarothayan, Hajananth. "Video based detection of normal and anomalous behaviour of individuals." Thesis, Queensland University of Technology, 2017. https://eprints.qut.edu.au/106947/1/Hajananth_Nallaivarothayan_Thesis.pdf.
Full textWorkman, Simon. ""A Criminal Strain Ran In His Blood": Biomedical Science, Criminology, and Empire in the Sherlock Holmes Canon." University of Cincinnati / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1505126689988603.
Full textKováč, Michal. "ANALÝZA MOŽNOSTÍ SIMULÁCIE A IMPLEMENTÁCIE AUTOSYNCHRÓNNYCH SUBSYSTÉMOV V OBVODOCH VLSI." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2010. http://www.nusl.cz/ntk/nusl-233515.
Full textGlisson, Wesley J., Courtney J. Conway, Christopher P. Nadeau, and Kathi L. Borgmann. "Habitat models to predict wetland bird occupancy influenced by scale, anthropogenic disturbance, and imperfect detection." WILEY, 2017. http://hdl.handle.net/10150/625200.
Full textSantos, Narciso Ferreira. "Contaminação do ar ambiental por radônio e filhos : estudo de características do 220Rn e filhos utilizando o detector CR-39." [s.n.], 2003. http://repositorio.unicamp.br/jspui/handle/REPOSIP/278106.
Full textTese (doutorado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin
Made available in DSpace on 2018-08-03T13:45:16Z (GMT). No. of bitstreams: 1 Santos_NarcisoFerreira_D.pdf: 3163623 bytes, checksum: b1421a9ac7f2e1a74969770dd60e8db1 (MD5) Previous issue date: 2003
Resumo: O objetivo desse trabalho foi o de caracterizar o detector de traços nucleares de estado sólido CR-39 para uma espectroscopia alfa adequada à medição das atividades do radônio e filhos, separando-se a atividade de 222Rn e filhos da atividade de 220Rn e filhos. Foi obtida a atividade do 222Rn separada da atividade do 220Rn mediante a exposição do CR-39 em uma seqüência regularmente espaçada de filmes finos de ar. Obtivemos um diagrama de tamanhos de traços e densidade óptica que distingue de forma inequívoca os traços produzidos por filhos de cada uma das cadeias. Obtivemos ainda uma medida da atividade dos filhos do 220Rn referidas à atividade do 222Rn em um ambiente sem ventilação. Para obter estes resultados produzimos uma fonte de chumbo 212 e construímos um dispositivo adequado à calibração do CR-39, para espectroscopia alfa. Indicamos um caminho para estender o método também a ambientes ventilados
Abstract: The aim of this work was to characterize the solid state nuclear track detector CR-39 to do an alpha spectroscopy suitable for measuring radon and radon daughter activities, distinguishing between 222Rn and daughters and 220Rn and daughters. The 222Rn and 220Rn activities were obtained separately through a regular sequence of thin films of air. We obtained diagrams of track size and optical density, which unequivocally distinguish the tracks yielded by daughters of each decay chain. We obtained a measurement of the 220Rn daughters¿ activity relative to the 222Rn activity in an environment without ventilation. In order to obtain these results we manufactured a lead-212 source and a device suitable for the calibration of the CR-39 for alpha spectroscopy. Finally, we give directions for applying the method also in ventilated environments
Doutorado
Física
Doutor em Ciências
Schilling, Alexander. "Model-based detection and isolation of faults in the air and fuel paths of common-rail DI diesel engines equipped with a lambda and a nitrogen oxides sensor /." Zürich : ETH, 2008. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17764.
Full textMonguilhott, Michele. "Avaliação de alterações na superfície agrícola a partir da técnica RCEN, em municípios do território da cidadania região central/RS." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2016. http://hdl.handle.net/10183/155987.
Full textPara análise da dinâmica territorial, é fundamental uma grande quantidade de dados e a integração com dados espaciais e estatísticos, facilita esse processo. A tese propõe analisar, a dinâmica da superfície agrícola de municípios do Território da Cidadania Região Central-RS (TCRCRS), território este que, faz parte de uma política pública de territórios da cidadania. Essa dinâmica, será analisada a partir de uma técnica de detecção de mudança, conhecida por Rotação Controlada por Eixo de Não Mudança - RCEN. Assim, a tese objetiva avaliar as alterações na superfície agrícola, no período de 1985 a 2010, em municípios do TCRCRS, utilizando o algoritmo RCEN. As seguintes etapas metodológicas, foram implementadas: utilização de imagens diferentes, para obtenção de pixeis amostrais de não mudança; análise qualitativamente da organização da superfície agrícola, para os municípios de Cacequi, Santiago e Tupanciretã, selecionados por sua localização em diferentes subunidades de paisagem no Estado; definição dos limiares, para delimitação das classes temáticas da organização espacial da superfície agrícola e, avaliação da confiabilidade dos resultados da técnica RCEN, utilizada pra determinar, a precisão da classificação supervisionada das imagens TM Landsat 5, através de uma matriz de concatenação. A matriz, é baseada em álgebra de mapas de tal maneira, a obter uma imagem numérica final que, expresse todas as possibilidades do espaço amostral. Os resultados, mostraram que, com 1% de significância, a técnica RCEN pode ser utilizada, para detectar a dinâmica na superfície agrícola, utilizando limiares de vigor vegetativo da IDETEC, comparados aos resultados dos índices Normalized Difference Vegetation Index (NDVI), que foi obtido considerando, o total de chuvas antecedentes a passagem do sensor, que é uma variável que interfere, nos valores médios de NDVI. Foram geradas imagens de detecção de mudanças (IDETEC), para analisar culturas agrícolas de inverno e de verão, obtendo-se 99% de confiança nas imagens selecionadas, para a distribuição espacial das classes definidas pela adoção dos limiares de ( - 0,5σ; – 1,5σ ; + 0,5σ; + 1,5σ), utilizando a como ponto central da classe de não mudança. As imagens de detecção de mudanças, permitiram estimar e comparar as classes da IDETEC, com as estimativas do total de área plantada, de lavouras temporárias, das culturas agrícolas de arroz, aveia, milho, soja e trigo As áreas obtidas pela IDETEC em Tupanciretã, superestimaram a área agrícola, apresentada pelo IBGE, nas imagens de verão com variações percentuais entre 1,11% na IDETEC 1994/2009 e 8,13% na IDETEC 2004/2010, para as imagens de inverno, a alteração foi de 9,46% na IDETEC 1989/2007 e de 3,44% na IDETEC 1996/2005. No município de Cacequi, as variações percentuais de lavouras temporárias foram superestimadas nas imagens de verão em 7,71% na IDETEC 1986/2006 e 20,47% na IDETEC 1993/2005 e, subestimadas nas imagens de inverno em 9,42% na IDETEC 1985/2003 e em 18,11% na IDETEC 1996/2007. Em Santiago, foram subestimadas para o período de verão em 24,76% na IDETEC 1984/2009 e, para o período de inverno em 10,52%, na IDETEC 1996/2005 e superestimadas em 8,23% na IDETEC 2004/2010 e, em 26,12% para a imagem de inverno IDETEC 1989/2007. A técnica RCEN, demonstrou ser capaz de estimar alterações na superfície agrícola, de culturas anuais para os municípios de Cacequi, Santiago e Tupanciretã.
For the analysis of territorial dynamics, a great amount of data is fundamental, and the integration of spatial and statistical data facilitates this process. This thesis proposes to analyze the dynamic of the agricultural surface in the Citizenship Country in the Central Area of Rio Grande do Sul (CCCARS), a country that is part of a public policy of citizenship countries. This dynamics will be analyzed by a change detection technique, known as Rotation Controlled of Non-change Axis (RCNA).Thus, this thesis aims to evaluate the alterations in the agricultural surface, in the period from 1985 to 2010, in CCCARS cities, using the RCNA algorithm. The following methodological steps were implemented: the use of different images in order to obtain non-change sampling pixeis; qualitative analysis of the organization of the agricultural surface in the cities of Cacequi, Santiago and Tupanciretã, which were selected due to their location in different subunits of landscapes in the State; determination of thresholds for the delimitation of thematic clusters in the spatial organization of the agricultural surface; and the evaluation of the reliability of the results of RCNA technique, which was used to determine the accuracy of the supervised classification of Landsat TM 5 images through a concatenating matrix. The matrix is based on the map algebra in such manner that expresses all the possibilities of the sampling space. The results showed that with 1% of significance, the RCNA technique can be used to detect the dynamics of the agricultural surface using threshold of the vigor of the vegetative growth compared with the results of Normalized Difference Vegetation Index (NDVI), which were obtained considering the total amount of rain previous to the sensor scanning, which is a variable that interferes in the medium values of NDVI. It was created images of changes detection (IDETEC) in order to analyze summer and winter agricultural crops, obtaining 99% of reliability on the selected images, for the special distribution of the defined clusters by the adoption of the threshold values of de ( - 0,5σ; – 1,5σ ; + 0,5σ; + 1,5σ), using the as a central point of nonchange cluster. The change detection images enabled to estimate and compare IDETEC clusters with the estimate of the total planted area of temporary farm, agricultural crop of rice, oat, corn, soybean and wheat. The areas obtained by IDETEC in Tupanciretã overestimated the agricultural area presented by IBGE, with summer images with percentage variance among 1,11% on IDETEC 1994/2009 and 8,13% on IDETEC 2004/2010, for the winter images, the alteration was of 9,46% on IDETEC 1989/2007 and of 3,44% on IDETEC 1996/2007. In the city of Cacequi, the percentage variance of the temporary farms were overestimated on the summer images in 7,71% on IDETEC 1986/2006 and 20,47% on IDETEC 1993/2005 and , and overestimated on the winter images in 9,42% on IDETEC 1985/2003 and in 18,11% on IDETEC 1996/2007. In Santiago, they were underestimated for the summer period in 24,76% on IDETEC 1984/2009 and , for the winter period in 10,52%, on IDETEC 1996/2005 e and overestimated in 8,23% on IDETEC 2004/2010 and, in 26,12% for the winter image IDETEC 1989/2007. The RCNA technique showed itself to be capable of estimating the agricultural surface alteration in annual crops in the cities of Cacequi, Santiago e Tupanciretã.
Merino, Pierrick. "Reproduction expérimentale du contact roue-rail à échelle réduite : Voies de formation des sources de défauts." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI101.
Full textThe safety issue is still the main concern of railway network due to the development of railway transportation and the increase of the amount of passengers. The understanding of the origin of the rolling contact fatigue (RCF) defect, is one key to safety requirements. The White Etching Layer associated to the initiation of the squat defect is hardly recreated. The use of laboratory test bench enable the replication of the wheel-rail contact. Nevertheless, only a fraction of the characteristic parameters is taken into account and compromises are necessary. The test bench “Triboring” built at LaMCoS, fulfills a gap in the existing apparatus. The “roller on circular rail” design was chosen to fit the tribological behavior of wheel-rail contact, and replicate RCF defects. The production of a test bench required to relate and differentiate the measured data to the phenomena corresponding to the operating from the phenomena corresponding to wheel-rail contact. The bench was characterized with dynamic and cinematic analysis. The design of the sample was improved. The tribological behavior of the bench was optimized with the preparation of the initial surface of the samples and the production of a tribological “fuse”. This layer delays the speed accommodation by wear and benefit the shear of the first bodies and the formation a Tribological Transformation of Surface (TTS), as the White Etching Layer. The two different fuse layer created (Run-in and oxidized), induced a significant wear reduction. The tribological and metallurgical analysis of the surfaces and cuts of the sample, enabled to the explanation of the evolution of the microstructure of the rail close to the surface, submitted to various mechanical solicitations. The transformation of this microstructure led to the formation of white etching layer mechanically formed
Figueiredo, Marcus Tadeu Tanuri de. "Análise dos procedimentos e critérios de implantação de feixes de raios X de referência ISO 4037 em baixas energias." CNEN - Centro de Desenvolvimento da Tecnologia Nuclear, Belo Horizonte, 2012. http://www.bdtd.cdtn.br//tde_busca/arquivo.php?codArquivo=260.
Full textAccording to the radiological protection principles, practices involving ionizing radiation must be planned and carried out under the guarantee that the values of individual doses, the number of people exposed to radiation and the probability of accidental exposures are as low as reasonably achievable. Therefore, radiation dosimetry is required to be done with reliable instruments designed for measuring dosimetric quantities. The reliability of the dosimetry depends on both the calibration of the dosimeter and its proper performance under certain test conditions. The International Standardization Organization (ISO), in order to promote international standardization and metrological coherency, established sets of reference X-ray beams for dosimeter calibration and typing-test; they are expected to be implemented in metrology laboratories in compliance with specific technical requirements. At low energies there are specific requirements that need to be considered in both the implementation of the reference beams and their use in calibration and testing. The present study is an analysis of the procedures and criteria for ISO 4037 reference radiation implementation, at low energies. In the Dosimeter Calibration Laboratory of the Development Center of Nuclear Technology (LCD / CDTN), experiments were performed for determining the X-ray reference radiation parameters. Alternatives to the usual methods for half-value layer determination were studied. Spectra of reference beams were simulated with software and compared with experimental measurements. Different climatic conditions were reproduced in the Laboratory for analysis of its influence on the determination of the beam parameters. Uncertainties in the measurements of studied parameters were evaluated. According to the ISO 4037 criteria, the low energy X-ray beams were considered to be implemented; they allowed the determination of the conversion coefficients from air kerma to the operational radiation protection quantities.
Torres, Guilherme Vaz. "Nova abordagem para o processamento e análise de imagens topográficas da córnea humana." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/59/59135/tde-03032008-090325/.
Full textThis work is about a software for the analisys of corneal topography images provided by commercial available systems to be implemented in a corneal topographer for slit lamps under evelopment at Laboratório de Instrumentação Oftálmica . EESC/USP e no Laboratório de Física Oftálmica . FRMP/USP. The software was developed in Borland C++ Builder for Windows and provides the corneal topography axial maps. The software has been tested in calibration spheres and in human eyes, presenting a correlation factor of 0,9998 for the measurements performed in the spheres and an inherent error of 3%. The axial topographic maps form the exams performe in human eyes have been compared to the axial maps provided by the commercial available system and the visual pattern as well as the relief are in accordance.
Karlsson, Oskar. "Lidar-based SLAM : Investigation of environmental changes and use of road-edges for improved positioning." Thesis, Linköpings universitet, Reglerteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-165288.
Full textSadoudi, Laïd. "Étude et développement d'une plateforme de communication pour les réseaux de capteurs acoustiques sans fil : application au contrôle-santé des rails par corrélation du bruit ambiant." Thesis, Valenciennes, 2016. http://www.theses.fr/2016VALE0018/document.
Full textStructural Health Monitoring (SHM) reduces human inspection requirements through automated monitoring, reduces maintenance costs by early detection of defects before they escalate, and improves safety and reliability of services. The work presented in this thesis aims to design a wireless communication platform for railway structures health monitoring. The control principle is based on the reconstruction of impulse responses (Green’s functions) by correlation of random noise propagated in the medium. In this work, direct comparison between an active emission-reception response and the estimated noise correlation function has confirmed the validity of the equivalence relation between them. Thus, we have demonstrated the applicability of the correlation functions for local defect detection in a rail. Then, we conducted an experimental study on the characterization of a ZigBee transmission in terms of path loss and communication range in multiple environments. In the railway environment under test, we showed the adequacy with the range of a ZigBee single-hop transmission (within a radius of 76m). Furthermore, a flexible solution for sensors synchronization during the sampling process, based on IEEE 802.15.4 standard was proposed and validated by a measurement campaign. It has been demonstrated that this approach provides a precision of a few hundred nanoseconds. A wireless communication-platform prototype based on the ZigBee/IEEE 802.15.4 technology has been implemented and deployed on a rail sample. This solution enabled the validation of the platform performances, once the data collected by the transducers, the information is transmitted by a ZigBee link to a base station where detection algorithms are applied
Rachedi, Nedjemi Djamel Eddine. "Modélisation et surveillance de systèmes Homme-Machine : application à la conduite ferroviaire." Thesis, Valenciennes, 2015. http://www.theses.fr/2015VALE0009.
Full textThe scope of the thesis is the monitoring of human-machine systems, where the operator is the driver of rail-based transportation system. Our objective is to improve the security of the system preventing and avoiding factors that increase the risk of a human error. Two major problems are identified: characterization, or how to determine indicative and discernible phases of driver's activity and representation, or how to describe and codify driver's actions and its repercussions on the rail system in a mathematical formalism that will allow unequivocal analysis. In order to bring a solution to those problems, we propose, first-of-all, a behavioral model of the human operator representing his control behavior in continuous-time. To consider inter- and intra-individual differences of human operators and situation changes, we propose a transformation of the latter behavioral model in a new space of representation. This transformation is based on the theory of Hidden Markov Models, and on an adaptation of a special pattern recognition technique. Then, we propose a discrete-time behavioral modeling of the human operator, which represents his actions and takes account of errors and unexpected events in work environment. This model is inspired by cognitive models of human operators. These two aspects allow us to interpret observables with respect to reference situations in order to characterize the overall human operator state. Different information sources are considered; as a result the data are heterogeneous and subject to measuring uncertainties, needing a robust data fusion approach that is performed using a Bayesian Network. Finally, the proposed modeling and fusion methodologies are used to design a reliable and unintrusive vigilance system. This system can interpret driving behaviors and to detect driver’s risky states in order to prevent drowsiness. The theoretical study was tested in simulation to check the validity. Then, a feasibility study was conducted using data obtained during experiments on the LAMIH laboratory railroad platform “COR&GEST”. These results allowed us to plan and implement experiments to be conducted on the future multimodal driving simulator “PSCHITT-PMR”
Eriksson, Niklas, and Patrik Lifvendahl. "Utbildningssimulator av funktioner i spårfordon : Hårdvarusimulator med felsökning på dörrsystem." Thesis, KTH, Data- och elektroteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-168951.
Full textThis report is a description of a developed educational simulator over rail vehicles and its components. The simulator is a hardware-based prototype over a door system on rail vehi- cles. System specialists and technicians will use the prototype. The Simulator should give the user a technical demonstration on how components work in a door system. The proto- type consists of motor, switch, relay and sensor. The components are used for illustration of the functions in a door system on a rail vehicle. The educational simulator is controlled with a control unit and with pushbuttons for manual control. For demonstration of the boarding security an optical sensor is used as symbolize for the obstacle detection. The educational simulation has two embedded common faults: cable fault and ground fault. The instruction manual consists of a circuit diagram and is used for troubleshooting. The circuit diagram over the door system is used to find the faults and to correct them. The fault analysis includes the factors, which is the reason for the most common faults to occur in a rail vehicle. Door system receives diagnostic code from a door computer that control priori- tizing for arrangements that will be made.
NOTARANGELO, NICLA MARIA. "A Deep Learning approach for monitoring severe rainfall in urban catchments using consumer cameras. Models development and deployment on a case study in Matera (Italy) Un approccio basato sul Deep Learning per monitorare le piogge intense nei bacini urbani utilizzando fotocamere generiche. Sviluppo e implementazione di modelli su un caso di studio a Matera (Italia)." Doctoral thesis, Università degli studi della Basilicata, 2021. http://hdl.handle.net/11563/147016.
Full textNegli ultimi 50 anni, le alluvioni si sono confermate come il disastro naturale più frequente e diffuso a livello globale. Tra gli impatti degli eventi meteorologici estremi, conseguenti ai cambiamenti climatici, rientrano le alterazioni del regime idrogeologico con conseguente incremento del rischio alluvionale. Il monitoraggio delle precipitazioni in tempo quasi reale su scala locale è essenziale per la mitigazione del rischio di alluvione in ambito urbano e periurbano, aree connotate da un'elevata vulnerabilità. Attualmente, la maggior parte dei dati sulle precipitazioni è ottenuta da misurazioni a terra o telerilevamento che forniscono informazioni limitate in termini di risoluzione temporale o spaziale. Ulteriori problemi possono derivare dagli elevati costi. Inoltre i pluviometri sono distribuiti in modo non uniforme e spesso posizionati piuttosto lontano dai centri urbani, comportando criticità e discontinuità nel monitoraggio. In questo contesto, un grande potenziale è rappresentato dall'utilizzo di tecniche innovative per sviluppare sistemi inediti di monitoraggio a basso costo. Nonostante la diversità di scopi, metodi e campi epistemologici, la letteratura sugli effetti visivi della pioggia supporta l'idea di sensori di pioggia basati su telecamera, ma tende ad essere specifica per dispositivo scelto. La presente tesi punta a indagare l'uso di dispositivi fotografici facilmente reperibili come rilevatori-misuratori di pioggia, per sviluppare una fitta rete di sensori a basso costo a supporto dei metodi tradizionali con una soluzione rapida incorporabile in dispositivi intelligenti. A differenza dei lavori esistenti, lo studio si concentra sulla massimizzazione del numero di fonti di immagini (smartphone, telecamere di sorveglianza generiche, telecamere da cruscotto, webcam, telecamere digitali, ecc.). Ciò comprende casi in cui non sia possibile regolare i parametri fotografici o ottenere scatti in timeline o video. Utilizzando un approccio di Deep Learning, la caratterizzazione delle precipitazioni può essere ottenuta attraverso l'analisi degli aspetti percettivi che determinano se e come una fotografia rappresenti una condizione di pioggia. Il primo scenario di interesse per l'apprendimento supervisionato è una classificazione binaria; l'output binario (presenza o assenza di pioggia) consente la rilevazione della presenza di precipitazione: gli apparecchi fotografici fungono da rivelatori di pioggia. Analogamente, il secondo scenario di interesse è una classificazione multi-classe; l'output multi-classe descrive un intervallo di intensità delle precipitazioni quasi istantanee: le fotocamere fungono da misuratori di pioggia. Utilizzando tecniche di Transfer Learning con reti neurali convoluzionali, i modelli sviluppati sono stati compilati, addestrati, convalidati e testati. La preparazione dei classificatori ha incluso la preparazione di un set di dati adeguato con impostazioni verosimili e non vincolate: dati aperti, diversi dati di proprietà del National Research Institute for Earth Science and Disaster Prevention - NIED (telecamere dashboard in Giappone accoppiate con dati radar multiparametrici ad alta precisione) e attività sperimentali condotte nel simulatore di pioggia su larga scala del NIED. I risultati sono stati applicati a uno scenario reale, con la sperimentazione attraverso una telecamera di sorveglianza preesistente che utilizza la connettività 5G fornita da Telecom Italia S.p.A. nella città di Matera (Italia). L'analisi si è svolta su più livelli, fornendo una panoramica sulle questioni relative al paradigma del rischio di alluvione in ambito urbano e questioni territoriali specifiche inerenti al caso di studio. Queste ultime includono diversi aspetti del contesto, l'importante ruolo delle piogge dal guidare l'evoluzione millenaria della morfologia urbana alla determinazione delle criticità attuali, oltre ad alcune componenti di un prototipo Web per la comunicazione del rischio alluvionale su scala locale. I risultati ottenuti e l'implementazione del modello corroborano la possibilità che le tecnologie a basso costo e le capacità locali possano aiutare a caratterizzare la forzante pluviometrica a supporto dei sistemi di allerta precoce basati sull'identificazione di uno stato meteorologico significativo. Il modello binario ha raggiunto un'accuratezza e un F1-score di 85,28% e 0,86 per il set di test e di 83,35% e 0,82 per l'implementazione nel caso di studio. Il modello multi-classe ha raggiunto un'accuratezza media e F1-score medio (macro-average) di 77,71% e 0,73 per il classificatore a 6 vie e 78,05% e 0,81 per quello a 5 classi. Le prestazioni migliori sono state ottenute nelle classi relative a forti precipitazioni e assenza di pioggia, mentre le previsioni errate sono legate a precipitazioni meno estreme. Il metodo proposto richiede requisiti operativi limitati, può essere implementato facilmente e rapidamente in casi d'uso reali, sfruttando dispositivi preesistenti con un uso parsimonioso di risorse economiche e computazionali. La classificazione può essere eseguita su singole fotografie scattate in condizioni disparate da dispositivi di acquisizione di uso comune, ovvero da telecamere statiche o in movimento senza regolazione dei parametri. Questo approccio potrebbe essere particolarmente utile nelle aree urbane in cui i metodi di misurazione come i pluviometri incontrano difficoltà di installazione o limitazioni operative o in contesti in cui non sono disponibili dati di telerilevamento o radar. Il sistema non si adatta a scene che sono fuorvianti anche per la percezione visiva umana. I limiti attuali risiedono nelle approssimazioni intrinseche negli output. Per colmare le lacune evidenti e migliorare l'accuratezza della previsione dell'intensità di precipitazione, sarebbe possibile un'ulteriore raccolta di dati. Sviluppi futuri potrebbero riguardare l'integrazione con ulteriori esperimenti in campo e dati da crowdsourcing, per promuovere comunicazione, partecipazione e dialogo aumentando la resilienza attraverso consapevolezza pubblica e impegno civico in una concezione di comunità smart.
Chen, Guan-jhih, and 陳冠志. "Physics-based Rain Removal for Moving Object Detection." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/71102568344561479948.
Full text國立中央大學
資訊工程研究所
98
Physical noises, such as rain, frequently affect the detection performance of moving-objects when they present in a film or a monitoring system. The elimination of physical noises is thus a prerequisite to uplift the detection accuracy. There are different kinds of noises needed to be eliminated under different weather conditions. The elimination of rain drops, due to the random spatial distribution and fast motion in short time, is hence admitted as a challenging problem. In this thesis, we improve the detection method of rain drops and construct the estimation on the intensity of background. Extensive studies were conducted in analyzing these algorithms. However, not all of the detected pixels contain real rain drops if merely find them based on the property of intensity change. To remove the false alarm, we use three effective features in our work and construct the environmental parameters of features by MLPNN (Multilayer Perceptron Neural Network) training. One of the features is the changed value of color from Cb and Cr. The probability of a pixel containing moving objects is higher if the changed value is high. The second feature is the information obtained by the sobel edge detector. Generally, the lower value in edge will exist in the rain area. The last feature is the saturation value of a pixel. A range of saturation values exists in the rain area. The result of classified method can be used for making decisions on false alarm, or we can use it on the algorithm in constructing the color-correlation to map more false alarms. The color-correlation is very useful for removing the false alarm in moving objects. The proposed method is implemented on object detection to find real foreground. We analyze the detecting accuracy with and without the rain removal system in the normal illumination cameras or films. The results show that the proposed system is indeed helpful on moving-object detection in the rainy weather. It really reduces the false alarm although the accuracy is not raised with the rain removal system.
Warburton, Michele Lynn. "Detection of changes in temperature and streamflow parameters over Southern Africa." Thesis, 2005. http://hdl.handle.net/10413/3514.
Full textThesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.
Chiang, Lee-Chen, and 姜禮城. "Ⅰ. Determination of the Chemical Oxgen Demand. Ⅱ. Determination the Efficiency of Detection Chemical Components and Physical Components for the Rainwater in Jong-Lih Area by Acid rain Automatic Monitoring." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/85025288337277938831.
Full text淡江大學
水資源及環境工程學系
87
Ⅰ. Determination of the Chemical Oxgen Demand in the Wastewater Using Microwave Energy — The Comparison Between the Closed Method And the Open Focus Reflux Method. In environmental analytic chemistry microwave-assisted methods for sample preparation have been increased rapidly in recent years .The closed vessel method and open focus reflux method were used for the determination of chemical oxygen demand (COD) in the digestion-oxidation step which was by using microwave energy. The goals of this study are to develop the mercury-free microwave assisted,digestion for COD determination and to compare between the open focus microwave and the closed vessel sample preparation methods. The optimized conditions for the closed vessel method are: sample, 5ml; sulfuric acid(0.55﹪Ag+), 7ml;0.0705M silver nitrate,1ml; 0.0417M potassium dichromate, 2ml; power(using domestic microwave oven): 512 W, reaction time: 5mins. The optimized conditions for the open focus reflux method are: sample, 5ml; sulfuric acid(0.55﹪Ag+), 7ml;0.0705M silver nitrate,1ml; 0.0417M potassium dichromate, 2ml; power(using open focus microwave oven): 300W, reaction time: 5mins. The average recovery of the closed vessel method for quality control samples were 98.3﹪and S. D. 1.8﹪.The average recovery of the open focus reflux method for quality control samples was 98.7﹪and S. D. 1.2﹪The ratio between COD values, determined by the open focus method and the closed vessel methods is 0.9360. The results show that both methods are comparable. Ⅱ. Determination the Efficiency of Detection Chemical and Physical Components for the Rainwater in Chung-Li Area by Acid rain Automatic Monitoring. The aims of this study are to characterize the rainfalls by physical and chemical parameter Chung-Li area and to compare the data from acid rain monitor with the results obtained in the laboratory. The physical and chemical parameters included temperature, rainfalls intensity, electrical conductivity, turbidity, pH value cation concentration (Na+,K+,NH4+,Ca2+,Mg2+) and anion concentration( Cl-,NO3-,SO42-).The results showed that the pH values, temperature, rainfalls intensity and electrical conductivity were very good as compared with that from the lab. However, the sulfate and nitrate by acid rain monitor, s spectrophotometer were poor probably because of bubbles and contamination in the line . Ion chromatography with conductivity detector has been used to determine cations and anions separately. The nitric acid solution(0.5mM) was used with cation-exchange column (MCI GEL SCK01) having low cation exchange capacities. The dilute 3mM Vanillin Acid and 2.8mM N-Methydiethanolamine(pH6.2) have been the main eluent species used for anions. The result shows the range of ratios (SO42 /NO3-)was 1~5 and the range of pH values were 4~7 for the rainwater in Chung-Li area.
Li, Yi-Chun, and 李亦鈞. "Road Detection System for Rainy Days." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/36054550849002039688.
Full text國立臺灣師範大學
資訊工程學系
103
The last two decades, for the driving safety, in-car video camera technology for estimating road shape ahead of a vehicle for the purpose of driver assistance has been developed and implemented. A road detection technology can provide the road shape, area and lane markings, which can share with other advance driver assistance systems (ADAS). Although road detection is a mature technology, there are a few studies on road detection for rainy days. Recent studies use mostly road boundary to detect road area. If road boundary is not clear, it would fail to detect the correct road area. To effectively handle road detection on rainy days, the proposed method comprises three modules: 1) log chromaticity space, 2) sensor sharpening matrix transform, and 3) watershed segmentation. To speed up the road detection processing, the region-of-interest (ROI) is used to choose the candidate searching range for extract road features. The system then process the log chromaticity space method and sensor sharpening matrix transform method. Finally, the watershed segmentation method as an error correction mechanism is applied. Experimental results on real road scenes such as light rain, moderate rain, and heavy rain show that if road scenes is bright enough and vehicles have vivid color, the proposed method has substantiated the effectiveness of accuracy results.
Hsieh, Chang-Ju, and 謝昌儒. "Real Time Traffic Sign Detection and Recognition in Rainy Weather." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/88404661299372975366.
Full text國立雲林科技大學
資訊工程系碩士班
100
In this paper, a new real time traffic sign detection and recognition system has been proposed. This system will focus on rainy weather and process the affects of the rainy weather on the prohibitory (red) and warning (blue) of traffic signs used in Taiwan by detection and recognition systems. First, the detection method is formed by combing RGB and HSI color space which apply well to detect traffic signs in rainy weather. The template matching was employed to classify the shape of candidates and the support vector machine was used to recognize the content of the traffic sign candidates. Our results show that the average detection rate is 90.78% and the average recognition rate is 89.13%.
Pereira, André Filipe Rainho. "Rail Corrugation: A Software Tool for Detection and Analysis Using Wavelets." Master's thesis, 2018. http://hdl.handle.net/10362/61576.
Full textJorge, Flávio Miguel da Silva. "High-order Earth-satellite propagation channel measurement and modelling at Ka and Q/V-bands." Doctoral thesis, 2020. http://hdl.handle.net/10773/28937.
Full textEste trabalho foca-se em links de comunicação Terra-espaço em microondas espectralmente eficientes e de elevada capacidade, suportando o acesso a larguras de banda maiores e menos congestionadas e ofereçendo os avanços tecnológicos necessários em termos de propagação de ondas de rádio para o projeto e operação de tecnologias de sistema que visam o uso otimizado do espectro, propondo a operação de esquemas de reuso de frequência e de técnicas de diversidade de polarização nas bandas Ka e Q/V. Porque o adequado planeamento, a implementação bem sucedida, bem como a efetiva operação, espectralmente eficiente e livre de interferências, de todos os sistemas e serviços espaciais está necessariamente relacionada e diretamente dependente, ainda que não exclusivamente, das condições do canal de propagação, este trabalho oferece uma abordagem completa e sistemática pretendendo a caracterização, compreensão, modelação e mitigação dos fenómenos de propagação relevantes. É provado existir uma maior margem operacional para a operação das tecnologias acima mencionadas do que aquela que se acredita existir considerando os modelos internacionais recomendados. São previstos maiores desafios, especialmente no que concerne à despolarização causada por gelo que é mais persistente e que dura mais tempo do que os correspondentes efeitos causados por chuva. De qualquer forma, a sua mitigação é possível e para a qual a despolarização deverá ser a variável de controlo. O intervalo de tempo de 15 minutos é identificado como o melhor compromisso entre tempo acessível e ganho alcançável no contexto de um esquema de diversidade temporal.
Programa Doutoral em Engenharia Eletrotécnica
(9820220), Sajith Mohan. "Development of a method for early detection of rail squats using eddy current inspection." Thesis, 2011. https://figshare.com/articles/thesis/Development_of_a_method_for_early_detection_of_rail_squats_using_eddy_current_inspection/13465619.
Full textFuong, Holly. "Social animals detecting danger: how social relations influence antipredator behavior in a noisy forest." Thesis, 2021. https://doi.org/10.7916/d8-vf2j-n792.
Full textChu, Yung-Hao, and 朱永浩. "Detection of Leading and Passing Vehicles on Highway through Computer Vision in the Rainy Day." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/32563776621709552356.
Full text國立中正大學
電機工程研究所
93
This thesis presents the techniques of computer vision and image processing for the detection of highway lanes and vehicles in the rainy day. This system acquires the road scene images from a forward-looking vehicle-mounted camera. After processing and analyzing these images, the system offers the information that the driver needs to improve the traffic safety. In this research, the lane markers are detected by first setting the area of interests in the scene image. We link and group the edge points that are connected, and then apply the least-square-error method to filter these edge-point segments to approximate the lane boundary. On the other hand, by combining the detection of vehicle taillights, the match for taillight pairing, and confirmation of the vehicles characteristic pattern, a reliable way of finding leading vehicles on highway in the rainy day can be derived with the supporting information from the continuous image stream. For neighboring vehicles detection, a scanning scheme is applied to the neighboring lane for detecting the possible vehicle sideline. The algorithm allocates an area of interests, checks the edge-point density and then detects vertical edges in that area to confirm the existence of neighboring vehicles. Testing with a large number of highway images in the rainy day, experimental results show the effectiveness of our proposed schemes; while the image processing time is fast enough to run in real-time on highway.
Raposo, Tiago Miguel de Góis. "C-RAN CoMP Methods for MPR Receivers." Master's thesis, 2018. http://hdl.handle.net/10362/61580.
Full text