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Dissertations / Theses on the topic 'Luminance analyser'
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1
Rampák, Dominik. "Hodnocení oslnění exteriérových osvětlovacích soustav." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442545.
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Glare is an important, but often overlooked parameter in lighting systems design. This parameter can significantly affect human biorhythm, causing a discomfort or in the worst cases it can dazzle drivers, which can lead to car accidents. Therefore, it´s necessary for lighting designers to consider glare in their designs, specifically threshold increment value. This thesis focuses on glare measurement caused by exterior lighting systems and comparison of usage different types of camera lens for threshold increment measurements with luminance analyser. For a better understanding of the whole issue, there is a part describing how human eye perceives light, which is followed by definition and division of the glare. Afterwards, there is part describing calculation procedure of the threshold increment, which serves as a basis for the practical part of the thesis. Practical part of the thesis is dedicated to experimental measurement of glare from exterior lighting system on Technická street, right behind VUT FEKT T12 building. The measurement is done using luminance analyser and the LumiDISP program, while 3 lenses are used for the measurements. The output of this thesis are values of threshold increment obtained by using 4 different methods (3 lenses) and subsequent comparison of the suitability of the lenses for the glare measurements. To supplement, a simulation of the measured lighting system in the Relux program and a subsequent comparison of the results with the measured values are performed.
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Vlček, Pavel. "Analýza schopnosti jasového analyzátoru LDA - LumiDISP měřit náhradní teplotu chromatičnosti." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442553.
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This master's thesis deals with the search of commercially available luminance analysers and cameras that use the measurement of correlated colour temperature. It also deals with calculations of correlated colour temperature according to various available methods. The luminance analyser LDA-LumiDISP is based on a DSLR camera. The principle of its operation and possible errors in capturing pictures are discussed here. The work deals with extensive testing of the LDA-LumiDISP luminance analyser, which is primarily intended for measuring luminance in the set scene, but can also be used to measure the correlated colour temperature. The device is being tested in terms of measuring the correlated colour temperature in laboratory and field conditions. The result of the master's thesis is the calculation of measurements uncertainty for certain light sources and the optimization of the measuring algorithm to reduce them.
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Škoda, Jan. "Nekonvenční metody měření ve fotometrii." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-233542.
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This thesis deals with an unconventional possibility of measuring photometric values and the work is based on analysis of luminance made by commercially available digital photo camera. In the first part is represent an overview of current methods for measuring the photometry. You also can see the basic photometric values and required instrumentation needed to measure them. The focus of the work is concentrated on the description of the problems associated with setting the correct luminance of digital photography. It describes the dependency and correction procedures for calculating fixed luminance ratios of the individual images. The last part of this thesis is devoted to the possible use in practice, especially in the analysis of luminance of objects, luminaires and light sources. It also deals with an alternative description of luminaire and light sources to replace the luminous intensity curve etc.
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Clark, Jerremy Eugene. "Nighttime driver needs: an analysis of sign usage based on luminance." Texas A&M University, 2003. http://hdl.handle.net/1969.1/5959.
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The need to see traffic signs at night has led to the development of increasingly brighter
retroreflective sign sheeting. The impact of this increased brightness has been shown to
increase the legibility distance of the sign, but at what cost? With brighter signs being
visible from farther away, there is an increased opportunity for the driver to look at the
sign. This thesis assesses the impact of sign brightness on the nighttime driverâÂÂs sign
viewing behavior; such as the number of glances and the total glance duration directed at
the sign.
Eye-tracking technology has been used to follow the nighttime driverâÂÂs eye movements
through tasks based on sign usage. The six signs used for the analysis are classified in
three relative brightness categories of bright, medium, and dim on a closed course and
on a public road. Data relating to the beginning and end of each glance were recorded as
well as the distance at which the sign became legible to the driver.
Comparisons were made between the three brightness levels for the number of glances,
total glance duration, and legibility distance of the sign. Further analysis was conducted
to determine the effect of the testing environment on a driverâÂÂs sign viewing behavior by
comparing the results from the closed course with those from the open road.
The data for this thesis show varying results between the two courses with more defined
differences based on luminance for the open road. The results of this thesis indicate that drivers do not consistently change the number of times they look at a sign or the amount
of time dedicated to a sign based on its brightness. During real world driving scenarios,
the brightest sign resulted in the longest legibility distance and the lowest total glance
duration, indicating an increased efficiency reading the sign by the driver. Typically, a
sign with a longer total glance duration had a shorter legibility distance. Comparisons
between the closed and open courses revealed that open road driving resulted in a longer
total glance duration and a shorter legibility distance.
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Persaud, Steven S. "Contrast Sensitivity to One- and Two-Dimensional Luminance Patterns." Thesis, Virginia Tech, 2001. http://hdl.handle.net/10919/9910.
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Contrast sensitivities to one- and two-dimensional luminance patterns were compared in a two-alternative forced choice (2AFC) experiment. Space-averaged luminance was also manipulated. Statistical analyses revealed a main effect of stimulus dimension (p < .05) and no effect of space-averaged luminance. The main effect of stimulus dimension was explained in terms of an on-center, off-center receptive field model combined with watershed spatial vision behavior at spatial frequencies below 1 cycle-per-degree (cpd). The non-significant result for space-averaged luminance was explained by the limited range of manipulation of the variable. Two-dimensional luminance patterns were suggested as ideal patterns for reconciling grating-based spatial vision research with spatial vision behavior in an ecological context. Future research directions are suggested.Master of Science
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Svoboda, Miloslav. "Srovnání konvenčních a nových metod měření a hodnocení jasů." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2012. http://www.nusl.cz/ntk/nusl-219397.
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Because luminance is the only value to which our sight responds, its measurement becomes important in terms of ensuring the proper function of vision. Nowadays luminance measuring can be made by conventional methods, such as direct using of luminance meter. However an entirely new method of measuring luminance levels is coming. This method is based on using luminance analyzers which work using a digital photography for the analysis of luminance. This thesis deals with these issues and is divided into several chapters, which form the two main parts of the thesis, the theoretical and the practical one. The theoretical part of the thesis deals with the basics of lighting technology, as well as the principles of measuring the luminance using conventional methods. New methods of measurement, i.e. using luminance analyzers, are discussed in two chapters which analyse both the principle and characteristics of analyzers available today. In the practical part is a comparative measurement carried out – in the laboratory and in terrain – using both methods.
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Ševčík, Ondřej. "Jasové skenování svítidel a světelných zdrojů." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-219906.
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Práce se zabývá měřením křivek svítivosti světelných zdrojů a svítidel konvenčními a nekonvenčními metodami. Úvodní část práce je věnována popisu zrakového systému a základních fotometrických veličin. Hlavní teoretická část je zaměřena na popis současných metod měření křivek svítivosti a nových metod měření pomocí jasového analyzátoru. Současně jsou pro jednotlivé metody uvedeny zdroje nejistot, které ovlivňují výsledky měření. Těžiště práce spočívá v návrhu metodiky měření křivek svítivosti z jasových skenů svítidla a následném ověření tohoto postupu vlastním měřením. Dále bylo provedeno srovnání naměřených výsledků navrženým postupem, s výsledky konvenčního měření na goniofotometru s luxmetrem.
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Luet, Mathieu. "Elaboration de deux spectromètres par transformée de Fourier utilisant des matériaux biréfringents : un spectro-polarimètre et un spectro-imageur." Paris 11, 2006. http://www.theses.fr/2006PA112253.
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Ce travail de thèse porte sur l’étude et la réalisation de deux spectromètres à transformée de Fourier utilisant des matériaux biréfringents. Le premier est un spectromètre statique utilisant une configuration innovante, à base de lame de Savart associée à une optique de Fourier. Il est destiné à la mesure de luminance spectrique de sources homogènes et il peut être transformé en spectro-polarimètre moyennant l’ajout d’une simple lame à retard en rotation. Le deuxième appareil est un imageur spectral construit autour de deux prismes de Wollaston dont l’un est mobile, en translation par rapport à l’autre. Il permet de faire l’image, en luminance spectrique, d’objets étendus avec une résolution spatiale pouvant aller jusqu’à 1000x1000 points. Dans les deux dispositifs, la mesure repose sur l’enregistrement d’un certain nombre d’images, constituées de franges d’interférence localisées sur une matrice de détecteurs et permettant de constituer un ensemble d’interférogrammes à partir desquels est appliqué un traitement de signal adapté (par transformée de Fourier) pour déterminer la luminance spectrique recherchée. Dans le spectro-polarimètre, chaque image constitue un interférogramme spatial, construit à partir de tous les détecteurs élémentaires. Dans l’imageur spectral, chaque pixel donne lieu à un interférogramme propre, qui est construit séquentiellement dans le temps, au fur et à mesure du déplacement du cube mobile. La résolution spectrale obtenue est de l’ordre de 5nm pour des domaines d’applications portant sur la qualité colorimétrique des écrans plats et l’analyse spectrale des pigments de peinture dans les œuvres d’artNew Fourier-Transform Spectrometers are carried out using birefringent materials. The first one is a static spectro-polarimeter using a calcite-made Savart plate with a Fourier optics. It is dedicated to measure the spectral luminance distribution and the polarization state of any homogeneous surface. The second instrument is a hyper spectral imager based on two symmetric fluorine-made Wollaston prisms, one moving linearly towards the other. It gives the spectral luminance distribution of an extended source up to 1000x1000 points. In both systems, the spectral information is extracted from interferograms, after a dedicated Fourier transform computation. In the polarimeter, the interferogram is spatially obtained on a two dimensional camera whereas, in the spectral imager, each pixel of the camera has its own interferogram, temporally constructed with the movement of the Wollaston cube. The spectral resolution achieved is about 5nm in the visible range and the instruments are well adapted for flat panel displays quality test and pigment painting detection
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Sivakumar, Praveen. "Analysis of Electron Transport and Luminance Mechanisms in SrS Based Blue Emitting ACTFEL Devices." UKnowledge, 2003. http://uknowledge.uky.edu/gradschool_theses/243.
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The purpose of this thesis is to contribute to the understanding of SrS based ACTFEL devices. Better understanding of the processes in the host phosphor will give us the possibility to design more efficient blue emitting ACTFEL devices. Towards this aim, a physical model, that describes the optoelectronic processes taking place in the phosphor, was developed and analytical equations were written. The analytical model was numerically simulated and the plots of flux flowing through the device and luminance output by the device were obtained. Experiments were performed to obtain the plots of current flowing through the device and luminance output by the device. These plots were then qualitatively compared and the results of comparisons are presented. The numerical simulations qualitatively verify the accuracy of the model. The drive parameters were varied in order to study its effect on the VIL characteristics of the device. On varying the voltage applied to the device and its rise and fall times, a good insight was obtained into device behavior. Simulations were also performed to obtain responses to qualitatively match the experimentally obtained responses. Various What-If scenarios have been studied by varying the device parameters. These studies have indicated the importance of these parameters in determining device performance.
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Brusque, Corinne. "Métrique du bruit visuel en site urbain nocturne pour l'optimisation des signaux routiers." Saint-Etienne, 1994. http://www.theses.fr/1994STET4006.
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Les scènes urbaines, en raison de la richesse de leur contenu, présentent l'inconvénient de générer un flux d'informations visuelles qui sollicite en permanence le système visuel de l'automobiliste. On identifie, sous la terminologie de bruit visuel, la nuisance générée par un tel environnement pour détecter les signaux routiers. L'objectif de la thèse est la définition d'une métrique, automatique et objective, du bruit visuel des scènes urbaines nocturnes. On a fait l'hypothèse qu'il était possible d'estimer l'intensité du bruit visuel généré, par un environnement urbain nocturne, à l'aide d'un paramètre physique quantifiant sa complexité visuelle. On a recherché, parmi les techniques de traitements d'images, celles qui permettaient au mieux d'estimer la complexité visuelle d'un environnement urbain. Les méthodes suivantes de traitement d'images ont été étudiées : l'analyse de l'histogramme des luminances, des techniques d'analyse de texture et l'analyse par ondelettes. On a, également, proposé une méthode, inspirée du calcul de la luminance de voile, pour décrire la répartition radiale de zones à forte luminance autour du signal. Une méthodologie statistique associant l'analyse factorielle et l'analyse typologique, a été retenue pour comparer le pouvoir de discrimination de la complexité visuelle, offert par chacune de ces méthodes. La métrique du bruit visuel proposée regroupe l'ensemble de ces outils. On a ensuite validé l'hypothèse initiale en comparant l'évaluation subjective, par des observateurs, du niveau du bruit visuel généré par un environnement et l'évaluation objective et automatique proposée
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Sivakumar, Praveen. "Analysis of electron transport and luminance in SrS based blue emitting A.C. thin film electroluminescent devices." Lexington, Ky. : [University of Kentucky Libraries], 2003. http://lib.uky.edu/ETD/ukyelen2003t00114/PKSThes.pdf.
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Thesis (M.S.)--University of Kentucky, 2003.Title from document title page (viewed Sept. 10, 2004). Document formatted into pages; contains xii, 140 p. : ill. Includes abstract and vita. Includes bibliographical references (p. 139).
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Novák, Filip. "Využití jasového analyzátoru pro kvantifikaci umělého světla v nočním prostředí." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442543.
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This diploma thesis deals with obtrusive light and its measurement, especially with the help of luminance analyzers. In particular, the necessary theoretical basis for the design of a measuring methodology for obtrusive light or veil brightness of the sky is laid here. This mainly includes the division of obtrusive light and its manifestations, a description of the effects of obtrusive light on the environment, selected organisms and the human body. Also described herein are the biological mechanisms of the human body that are affected by light as such. Attention is also paid to streetlights, its classification and methods of reducing obtrusive light, as well as methods of measuring brightness and brightness analyzers. Last but not least, the night sky is also measured using the LumiDISP luminance analyzer and subsequent data are evaluated using the proposed method.
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Kutý, Tomáš. "Blízká fotometrie." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-221203.
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This thesis is focused on the theoretical and practical introduction to the verification procedures used today for obtaining luminosity curves of lamps. The introduction acquaints readers with the photometric variables. Consequently, it is theoretically described procedure for constructing luminance curves by zonal flow and further familiarization with the near-field photometry. For the practical part was chosen several lights. These lamps were measured by luxmeter first from a very close photometric distance from lights, and then from large distance. The next step was to obtain pictures of luminaries in planes C 0 to 345 ° (with a step of 15 °) of the angle gamma from 0 to 180 ° (in steps of 5 °). The measured data were processed by zonal flow and through programs LumiDISP and Matlab. The partial result of this thesis is to verify whether it is possible to use the luminance analyzer for obtaining luminosity curves, it means, if the luminosity curve obtained through luminance analyzer will comply with the curves obtained through a luxmeter. Further work should ascertain the feasibility of acquired photographs lamps from a very close photometric distance could create luminosity curve for any location and distance from the observer to measured lamps.
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Souza, Dennis Flores de 1984. "High dynamic range imaging applied to the study of sky vault luminance distribution mapping = Imagens de grande alcance dinâmico aplicadas ao mapeamento da distribuição de luminâncias da abóbada celeste." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/257968.
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Orientadores: Paulo Sergio Scarazzato, Hélio PedriniTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo
Made available in DSpace on 2018-08-26T13:49:42Z (GMT). No. of bitstreams: 1 Souza_DennisFloresde_D.pdf: 57790978 bytes, checksum: b6823404106d40d260ee7c43d24ecaa9 (MD5) Previous issue date: 2014
Resumo: O uso de imagens de grande alcance dinâmico (HDR) nos estudos de iluminação vem se tornando um expediente frequente pela capacidade de armazenamento de dados referentes à distribuição de luminâncias em uma cena. Diversos estudos comprovaram, por exemplo, as possibilidades de registro da luz natural por imagens digitais, uma vez que as características das imagens HDR puderam melhorar os resultados. Dentre as diferentes aplicações, o registro da abóbada celeste é um dos que mais pode se beneficiar dessa ferramenta, pois tal procedimento é mais simples do que aqueles realizados a partir de medições feitas por luminancímetros ou escâneres de céu. Além disso, atualmente a identificação dos tipos de céu ainda é feita em sua maioria utilizando métodos subjetivos. Isto se deve ao fato de não existir uma metodologia para comparar imagens HDR com modelos matemáticos, apenas métodos unidimensionais que focalizam um ou outro aspecto. Esta pesquisa teve por objetivo desenvolver um método multidimensional de identificação, classificação e extração de dados de iluminação natural a partir de imagens HDR da abóbada celeste. As imagens das câmeras foram calibradas segundo métodos disponíveis para estabelecer a confiabilidade da análise e interpretação dos dados, e foram obtidas em localidade com o mínimo de obstrução à visão da abóbada celeste. O método multidimensional de análise foi desenvolvido juntamente a uma rotina em MATLAB, que serviu ao propósito de verificar sua viabilidade e a precisão. Os dados extraídos foram testados na plataforma Flash, usando a linguagem ActionScript 3, para brevemente demonstrar as possibilidades de uso. Este método utiliza um sistema de classificação baseado na relevância das características identificadas na imagem, como a cobertura de nuvens e a distribuição de luminâncias, para escolher o tipo de céu da norma ISO 15469:2004 (e) / CIE S 011/E:2003 mais apropriado. Os resultados apontam para a viabilidade desse método em escolher o tipo de céu mais relevante de acordo com os dados extraídos da imagem HDR. A proposição deste método multidimensional de análise pode contribuir para a criação de um sistema de classificação e de um banco de dados digital úteis para futuros programas de simulação, providenciando dados de entrada obtidos a partir de medições de uma realidade física, facilmente registrada com precisão e confiabilidade a partir de imagens fotográficas
Abstract: Lately, the high dynamic range images (HDR) have experienced a significant growth in their usage in lighting studies, due to their capacity to store data of luminance distribution in a scene. Various studies have attested, for instance, the possibilities of using digital images in the register of daylighting, since the features of HDR images could enhance the results. Among different applications, the record of the light on the sky vault is one that can benefit most from HDR techniques, because this procedure is simpler than those performed by luminance meters or sky scanners measurements. Besides, the identification and classification of sky types are still done mostly by subjective methods. This can be explained by the unavailability of a methodology able to compare HDR images with mathematical models, although there are unidimensional methods that focus on one or another aspect of digital images. This research aimed at the development of a multidimensional method of identification, classification and extraction of daylight data from HDR images of the sky vault. The images registered by the camera were calibrated using available methods to establish the reliability of the analysis and interpretation of data. They were then obtained on a site with minimal obstruction to the vision of the sky vault. The multidimensional analysis method was developed in conjunction with a routine in MATLAB, which served the purpose of verifying its feasibility and accuracy. The extracted data were tested in Flash platform using ActionScript 3 language to briefly demonstrate the usage possibilities. This method relies on a classification system based on the relevance of the features identified in the image, such as cloud covering and luminance distribution, to choose the most appropriate sky type according to ISO 15469:2004 (e) / CIE S 011/E:2003 Standard. The results demonstrate the feasibility of this method in choosing the most relevant sky type according to the data extracted from the HDR image. The proposition of this multidimensional analysis method may contribute to the creation of a classification system and a digital database useful for future simulation software, providing input data from measurements of a physical reality, easily recorded with accuracy and confidence by photographic images
Doutorado
Arquitetura, Tecnologia e Cidade
Doutor em Arquitetura, Tecnologia e Cidade
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Fazekas, Tibor. "Hodnocení kvality osvětlení s využitím moderních softwarových prostředků." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-218859.
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This thesis deals with the evaluation of the quality of lighting with the usage of the latest software products used nowadays. The first part of the work is about indoor lighting, the basic requirements invested in lighting, and the basic concepts of indoor lighting. The second part includes complete search for today's computer implements for projecting, simulating, calculation and analysis of light, their functions and characteristics, including luminance analyzers based on CCD sensors and their software equipment. The last part of the work has the task to model a computer room using softwares which can be found within the territory of VUT Brno, and the task was to assess its lighting. Following this, with the help of luminance analyzer, the task is to capture the scene under different lighting conditions and to evaluate the measured data.
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Šťastný, Jakub. "Oslnění od svítidel s neuniformní vyzařovací plochou." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2018. http://www.nusl.cz/ntk/nusl-376927.
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In the field of lighting technology, glare evaluation is one of the basic parameters of determining the quality of lighting systems. Disturbing glare is most often evaluated by UGR in internal systems. The UGR method is well described and verified for uniform glare sources. With the development of LED, non-uniform sources of glare become involved in the lighting system. Thus verification of UGR suitability for non-uniform sources is necessary and possibly modification of the method or replacement it by another more appropriate method is required. This diploma thesis focuses on evaluation methods of disturbing glare from luminaires with non-uniform radiation surface. For this purpose, the thesis includes glare analysis, methods of glare calculation and glare evaluation. Furthermore, the UGR analysis and modification for the calculation of disturbing glare from non-uniform glare sources are included. The practical part is concentrated on measurement of glare from uniform and non-uniform glare sources. For the purpose of evaluating the suitability of the measurement method, the subjective evaluation of glare from a statically significant sample is included in the thesis.
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Angulo, Lopez Jesus. "Morphologie mathématique et indexation d'images couleur : application à la microscopie en biomédecine." Phd thesis, École Nationale Supérieure des Mines de Paris, 2003. http://tel.archives-ouvertes.fr/tel-00007524.
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Dans le domaine de l'image numérique en microscopie biomédicale, la couleur constitue une source importante d'information, laquelle combinée avec la géométrie et la morphologie des structures, permet le développement de techniques quantitatives plus performantes et robustes. Et ceci est aussi le cas dans le domaine des applications multimédia, notamment pour l'indexation automatique par le contenu. Néanmoins, la représentation et le traitement des images couleur reste un problème ouvert.Cette thèse se propose d'explorer des méthodes à caractère générique pour la segmentation, le filtrage et l'extraction de caractéristiques des images couleur, en se fondant sur des opérateurs de la morphologie mathématique. D'un point de vue plus pratique, les deux applications spécifiques considérées sont la cytologie quantitative hématologique et la lecture de puces à ADN.
Dans un premier temps, nous traitons le problème des espaces couleur. Des résultats mathématiques justifient l'usage des systèmes de coordonnées de type teinte/luminance/saturation. Nous montrons par ailleurs les avantages pratiques de telles représentations lorsqu'on bâtit des histogrammes bidimensionnels teinte/saturation et luminance/saturation pour segmenter les images couleur et pour extraire des reflets, des zones d'ombre et des dégradés sur les images couleur.
Ainsi, nous pouvons aborder l'extension de certains opérateurs morphologiques pour le filtrage et la segmentation d'images couleur ou multispectrales, le but principal étant de développer des opérateurs couleur, extension des opérateurs scalaires, qui soient adaptés aux caractéristiques avantageuses des espaces couleur type teinte/luminance/saturation. Notamment le fait d'avoir à notre disposition l'information chromatique et l'information achromatique d'une manière indépendante, ainsi qu'une information comme la saturation qui joue le rôle de poids de contrôle entre les deux, nous permet de proposer quelques façons différentes de filtrer/segmenter conjointement les structures chromatiques et achromatiques d'une image couleur. Un grand nombre d'exemples ont montré l'intérêt de cette approche.
Nous montrons ensuite les résultats de différentes études concrètes sur la caractérisation et la classification de la forme, la texture et la couleur des objets d'une image grâce aux opérateurs tels que les granulométries et les histogrammes couleur.
Dans la dernière partie, nous abordons deux applications en microscopie biomédicale quantitative. La première application correspond à une plate-forme technologique intégrée pour la segmentation, l'extraction de caractéristiques et la classification de cellules dans des frottis de sang périphérique, dans le cadre d'applications en réseau (téléhématologie). Dans la deuxième application, nous utilisons les opérateurs morphologiques les plus avancés dans une approche automatique très performante pour l'extraction des données des spots de l'image d'une puce à ADN.
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Jehl, Augustin. "Etude photométrique de la surface de Mars à partir de la caméra HRSC à bord de la sonde Mars express : préparation aux observations orbitales multi-angulaires en exploration planétaire." Toulouse 3, 2008. http://www.theses.fr/2008TOU30091.
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Parmi les études novatrices que l'on peut aborder depuis l'orbite martienne en utilisant les données multiangulaires de l'instrument HRSC (canaux nadir, stéréographique et photométrique) de Mars Express, figure la détermination des caractéristiques physiques de la surface, pour cartographier les variations des propriétés physiques des sols et des roches de Mars et les relier aux observations spectroscopiques et thermiques réalisées par les instruments OMEGA, TES et THEMIS. Les modèles de Minnaert et de fonction de phase à deux termes de Hapke s'accordent pour démontrer que les observations multiangulaires de HRSC acquises au cours de la mission sur le cratère Gusev et le flanc sud de Apollinaris peuvent, sous certaines limites, être assemblées pour produire une fonction de phase couvrant un grand intervalle d'angles de phase (5-95°) avec une résolution spatiale de l'ordre de 400 mètres à 1. 6 kilomètres. Combiné à la rugosité de surface, l'effet d'opposition joue un rôle significatif, suggérant que les propriétés optiques de l'état de surface au niveau de Gusev sont fortement influencées par la porosité, l'état de compaction et l'organisation de la couche superficielle du régolite. L'aspect cartographique de la présente étude photométrique est utile pour donner une meilleure signification aux variations observées. Selon les tendances générales de cette analyse, il est très probable que la variation photométrique observée, au moins pour les régions centre et Ouest du cratère Gusev, soit partiellement due aux régimes des vents dominants, ces derniers ayant une orientation Nord - Nord Ouest / Sud - Sud Est et induisant une perturbation de la couche supérieure de la surface. .One of the new investigations from orbit that can be addressed with the multi-angular HRSC/ Mars-Express dataset generated with the nadir-looking, stereo and photometric channels, is to derive the surface photometric characteristics for mapping the variation of the soil/bedrock physical properties of Mars, and to relate them to the spectroscopic and thermal observations produced by OMEGA, TES and THEMIS instruments. Minnaert and two-term phase function Hapke models concur to demonstrate that HRSC multi-angular observations acquired over Gusev crater and Apollinaris southern flank along the ongoing Mars-Express mission can be, under some limitations, pieced together to derive integrated phase functions over a wide range of phase angles (5-95°) at moderate spatial resolution on the order of 400 m-1. 6 km. In combination with the surface roughness variation, the opposition effect appears to play a significant role suggesting that the surface state optical properties across Gusev are strongly influenced by the porosity and packing characteristics of the upper layer of the Martian regolith. The mapping aspect of the present photometric investigation is quite useful to get a better sense of the meaning of the observed variations. Given the overall patterns derived from this analysis, it is quite likely that the observed photometric variation at least for the western and central part of Gusev crater is partly driven by the prevailing wind regimes considered to be oriented north-northwest / south-southeast and disturbing the very upper surface layer. .
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Ahmed, Mustafa M. Abdalla. "Alternating-Current Thin-Film Electroluminescent Device Characterization." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2008. http://www.nusl.cz/ntk/nusl-233432.
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Jádrem této disertační práce bylo studovat optické a elektrické charakteristiky tenkovrstvých elektroluminiscenčních součástek řízených střídavým proudem (ACTFEL) a zejména vliv procesu stárnutí luminiforů na jejich optické a elektrické vlastnosti. Cílem této studie měl být příspěvek ke zvýšení celkové účinnosti luminoforů, vyjádřené pomocí jasu, účinnosti a stability. Vzhledem k tomu, že současnou dominantní technologií plochých obrazovek je LCD, musí se další alternativní technologie plošných displejů porovnávat s LCD. Výhodou ACTFEL displejů proti LCD je lepší rozlišení, větší teplotní rozsah činnosti, větší čtecí úhel, či možnost čtení při mnohem vyšší intenzitě pozadí. Na druhou stranu je jejich nevýhodou vyšší energetická náročnost, problém s odpovídající barevností tří základních barev a podstatně vyšší napětí nutné pro činnost displeje. K dosažení tohoto cíle jsme provedli optická, elektrická a optoelektrická měření ACTFEL struktur a ZnS:Mn luminoforů. Navíc jsme studovali vliv dotování vrstvy pomocí KCl na chování mikrostruktury a na elektroluminiscenční vlastnosti (zejména na jas a světelnou účinnost) ZnS:Mn luminoforů. Provedli jsme i některá, ne zcela obvyklá, měření ACTFEL součástek. Vypočítali jsme i rozptylový poměr nabitých barevných center a simulovali transportní charakteristiky v ACTFEL součástkách. Studovali jsme vliv stárnutí dvou typů ZnS:Mn luminoforů (s vrstvou napařenou či získanou pomocí epitaxe atomových vrstev) monitorováním závislostí svítivost-napětí (L-V), velikost vnitřního náboje - elektrické pole luminoforu (Q-Fp) a kapacitance-napětí (C-V) ve zvolených časových intervalech v průběhu stárnutí. Provedli jsme krátkodobá i dlouhodobá měření a pokusili jsme se i o vizualizaci struktury luminoforu se subvlnovým rozlišením pomocí optického rastrovacího mikroskopu pracujícího v blízkém poli (SNOM). Na praktickém případu zeleného Zn2GeO4:Mn (2% Mn) ACTFEL displeje, pracujícího při 50 Hz, jsme také studovali stabilitu svítivosti pomocí měření závislosti svítivosti na napětí (L-V) a světelné účinnosti na napětí (eta-V). Přitom byl zhodnocen význam těchto charakteristik. Nezanedbatelnou a neoddělitelnou součástí této práce je i její pedagogický aspekt. Předložený text by mohl být využit i jako učebnice pro studenty na mé univerzitě v Lybii.
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Hsu, Hsu-Sheng, and 徐旭昇. "Electronic Paper Luminance Enhancement Analysis and Simulation Design." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/70336750240130543171.
Full textAbstract:
碩士國立中央大學
光電科學研究所碩士在職專班
98
On the design of integrating luminance enhancement films into electronic paper (e-paper) display for higher brightness (reflectivity). Electrophoretic display (EPD) was selected as the e-paper technology for study. We started out by studying the surface property of e-paper and original enhancement film. Measurement and analysis on the optical and structural properties of the film were conducted in order to fully understand the optical enhancement and its impact to the surface reflectivity. Computational simulation was then carried out to optimize the structural design of the film. In the end, the optimal design was used to build the actual enhancement film for verification of the proposed solution. Based on this study, we achieved the goal of e-paper brightness enhancement with structure design that is less complicated to fabricate. The brightness enhance from this work is less prone to the impact of light incident angle and the enhancement is up to 130% of original design. Further simulation work was carried out for to explore the enhancement of asymmetric structure, two-dimensional structure and micro-lenses structures: asymmetric structure was predicted to achieve 110% luminance when incident light is angled within certain range. Also, two-dimensional structure could achieve enhancement at certain incident angle regardless the direction of the light. To summarize this work: we optimized the structural design of e-paper enhancement film and identified the impact of film structure to e-paper surface reflectance at different light incident angles. This work also provided the base for further structural optimization of enhancement film in order to adapt to the environment with different light incident angle. The observation and learning from this work can be further leveraged to colorful e-paper or other e-paper technology for the purpose of display brightness enhancement as the direction of future work.
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Chen, Hsin-Chia, and 陳信嘉. "A Study of Image Analysis Techniques Based on Luminance/Color Contrast." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/33055881755910767398.
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博士國立交通大學
電子工程系所
95
In this dissertation, a study of image analysis techniques by correlating subjective visual qualities with objective visual quantities based on luminance/color contrast is presented. To mimic the way humans perform image analysis, some subjective visual quantities are considered. To extract and verify the applicability of these visual quantities, subjective experiments are performed first. Then, to measure these subjective visual quantities, some objective quantitative measures based on luminance/color contrast are proposed. With these objective quantitative measures, contrast-based image analysis techniques can be developed for various image analysis applications. In the flow chart of a conventional image analysis system, four basic parts are included: 1) inputting of images to be analyzed, 2) image analysis with one or more techniques, 3) outputting of analyzed results, and 4) evaluation of the analyzed results. Specifically, given one or more images to be analyzed, different image analysis techniques are adopted for different applications. Then, the analyzed results are evaluated with some evaluation methods according to predefined visual perception requirements. In this dissertation, two more processes are added into an image analysis system. They are 1) subjective experiments and 2) measurement of luminance/color contrast and/or measurement of visual perception quantities. To mimic the way humans perform image analysis, we need some suitable subjective visual quantities. To extract appropriate visual quantities that may well correspond to humans’ perception, subjective experiments are needed. To estimate these subjective visual quantities for different applications, we need to propose effective and efficient objective quantitative measures. In this dissertation, we consider two different image analysis applications: 1) automatic inspection for visual defects on LCD panels, and 2) color segmentation. For different image analysis applications, the applicable visual quantities will be different. In the automatic defect inspection application, we discuss the suitable visual quantities for the extraction of visual defects with low luminance contrast. Here, we follow Mori’s proposal to quantify the degrees of image defects based on the luminance contrast and area size of visual defects. Based on Mori’s subjective experiments, which were performed to relate human visual perception with the luminance contrast and area size of visual defects, and the SEMU formula, which was proposed by Mori et al for a quantitative measurement of visual perception, we may effectively quantify the degrees of image defects based on luminance contrast and defect area. The LOG operator is then used to detect several types of visual defects. An optimal thresholding mechanism is also discussed. For the applications of color segmentation with little texture, we consider segmentation quality, degree of over-segmentation, and degree of under-segmentation as the visual quantities. To verify the correlation among these visual quantities, a few subjective experiments are performed. Here, we use color contrast to quantify these visual quantities. Usually, given a color image, adjacent pixels with low color-contrast are grouped into regions; while adjacent pixels with high color-contrast are regarded as edges. For color segmentation, we define color-contrast in terms of visible color difference and invisible color difference. Then, some objective quantitative measures based on visible/invisible color difference are proposed to measure these aforementioned subjective visual quantities. In this dissertation, the “intra-region visual error” is proposed to measure the degree of under-segmentation, while the “inter-region visual error” is proposed to measure the degree of over-segmentation. With these visual measures, some image analysis techniques are proposed to perform color segmentation and also the evaluation of color segmentation. With simulations for these two image analysis applications, some conclusions are drawn. First, the correlations between the luminance/color contrast-based quantitative measures and the visual quantities are really significant. Second, luminance/color contrast may play an important role in the development of image analysis techniques that mimic the way of human perception.
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Tsai, Chi-tsung, and 蔡騏聰. "The Experimental Luminance Analysis of CCFL Thermal Effects on LCD Backlight Module." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/ky9yr4.
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碩士國立中山大學
機械與機電工程學系研究所
95
Liquid crystal displays (LCDs) have been widely used in the information technology such as LCD-TV, LCD monitor, laptop computer and mobile phones. Because liquid crystal does not emit lights by itself, a backlight source should be needed in order to produce viewable images on a LCD. The module which provides the light source is usually called ‘‘backlight module (BLM)’’ and a cold cathode fluorescent lamp (CCFL) is used as the light source, which is placed behind the panel of the LCD. Due to the temperature increase of the CCFL in a BLM of a LCD subjected to lighting state, micro-deformation will occur in the BLM and result uneven luminance phenomena. The purpose of this research is to study the effects of heat source from CCFL on luminance in the BLM of a 7-inch LCD. The temperature distributions are measured by using thermal couple and the luminance variations of the BLM are measured by using luminance meters and CCD camera. The results show that the luminance distribution is more even because of the heat source from CCFL in BLM.
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Yi-PingWang and 王怡蘋. "Analysis and Verification of LED Luminaire Standards." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/92434694928392181013.
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碩士國立成功大學
電機工程學系專班
101
In this thesis, a LED MR16 lamp that meets the requirements of IES-LM-79-08 Electrical and Photometric Measurements of Solid-State Lighting Products is designed and implemented. The proposed LED lamp consists of a LED module driving circuit and a heat sink. The LED modules selected for MR16 lamp can meet the requirements of IES-LM80-08 Measuring Lumen Maintenance of LED Light Sources. The first-order optical simulation conducted with TracePro® was done by using the optical specifications provide by CREE LED to verify the optical characteristics of the LEDs. The second-order optical lenses are designed according to the first-order optical properties of LEDs. The heat sink is designed and the thermal simulation analysis is also conducted. Finally, a 3.6W LED MR16 lamp with the luminous efficiency of 88 lm/W, color rendering index of 83.5, and the view angle of 36.5degrees is implemented. Experimental results show that the proposed lamp meets the requirements of the standards and can be used to replace the traditional 20W MR16 halogen bulb. Furthermore, the proposed LED lamps can save up to 82% of the electricity compared to the traditional halogen bulbs.
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"A Diagnostic Tool for Assessing Lighting in Buildings: Investigating Luminance Contrast Relationships Through High-Dynamic-Range Image Based Analysis." Doctoral diss., 2011. http://hdl.handle.net/2286/R.I.9396.
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abstract: This study examines the applicability of high dynamic range (HDR) imagery as a diagnostic tool for studying lighting quality in interior environments. It originates from the limitations in lighting quality assessments, particularly from the problematic nature of measuring luminance contrast--a significant lighting quality definer. In this research, HDR imaging method is studied systematically and in detail via extensive camera calibration tests considering the effect of lens and light source geometry (i.e. vignetting, point spread and modulation transfer functions), in-camera variables (i.e. spectral response, sensor sensitivity, metering mode,), and environmental variables (i.e. ambient light level, surface color and reflectance, light source spectral power distribution) on the accuracy of HDR-image-derived luminance data. The calibration test findings are used to create camera setup and calibration guidelines for future research, especially to help minimize errors in image extracted lighting data. The findings are also utilized to demonstrate the viability of the tool in a real world setting--an office environment combining vertical and horizontal tasks. Via the quasi-experimental setup, the relationship between line of sight and perceived luminance contrast ratios are studied using HDR images. Future research can benefit from the calibration guidelines to minimize HDR-based luminance estimation errors. The proposed tool can be used and tested in different contexts and tasks with varying user groups for revising the former luminance-contrast guidelines as well as surface reflectance recommendations.Dissertation/Thesis
Ph.D. Architecture 2011
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Chiu, Bo-Chun, and 邱博鈞. "The study about design and analysis for high efficiency RGB LEDs projection luminaire." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/79575085527078909049.
Full textAbstract:
碩士國立中央大學
光電科學研究所
99
In this thesis, the main object is the design of RGB LEDs projection luminaire. Its color is adjustable, and if using in producing white-light, we can change the CCT. However, the important issues in this luminaire are optical efficiency and color uniformity. Therefore, we will define the method of measuring and analyzing for color uniformity in the thesis. Moreover, we will also discuss each parameters in the luminaire to find the suitable structure. Finally, we design the high efficiency projection luminaire with color-mixing.
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Lee, Pai Fang, and 李佩芳. "A Study on Permanent Supplementary Artifical Lighting of Interio- rs for Office:Experiment and Analysis of Visual Perception by Wi- ndow Luminance Variance." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/08999148923479719942.
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