National Repository of Grey Literature 37 records found  beginprevious21 - 30next  jump to record: Search took 0.00 seconds. 
Measurement of illuminance distribution on roadways using the luminance analyser LDA
Cudrák, Martin ; Škoda, Jan (referee) ; Motyčka, Martin (advisor)
The master's thesis deals with the possibility of measuring road illuminance using the LDA luminance analyser and LumiDISP software. The theoretical part describes luminous quantities, optical properties of selected materials, especially road materials – asphalt, and normative requirements for road lighting. In the practical part, the production of measuring samples is implemented for subsequent field measurements. A series of laboratory and field measurements are carried out in the following section. Based on these measurements, the measurement method and the measurement procedure have been determined and refined. The aim of the master's thesis is to determine the measurement method, the measurement procedure and to quantify the accuracy of the illuminance measurement method using the luminance analyser LDA.
Glare evaluation of exterior lighting systems
Rampák, Dominik ; Baxant, Petr (referee) ; Škoda, Jan (advisor)
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.
Development of Light Emitting Electroluminescent Device by Means of Material Printing
Hrabal, Michal ; Syrový,, Tomáš (referee) ; Boušek, Jaroslav (referee) ; Vala, Martin (advisor)
Cílem této práce je vývoj světelného zdroje založeného na technologii tlustostěnného elektroluminiscenčního panelu napájeného střídavým napětím (ACPEL). V současné době se jedná se o jedinou technologii založenou na metodách materiálového tisku vhodnou pro přípravu velkoplošných, flexibilních a vzorovaných zdrojů světla. Důraz je v této práci kladen na představení, prozkoumání a odstranění typických problémů, které jsou spojovány s touto technologií. Tyto problémy jsou omezený odstín barvy emitovaného světla a dlouhodobá stabilita elektroluminiscenčního prvku, který je vystaven vlivům prostředí. Rešeršní část dizertační práce je zaměřena na představení a identifikaci depozičních technik, vhodných pro reprodukovatelnou přípravu ACPEL panelů. Dalším cílem je identifikace fyzikálních parametrů, vhodných pro charakterizaci velkoplošných zdrojů světla. Praktickým cílem práce je nalezení vhodné metodologie pro popis a charakterizaci panelů, jakožto plošných světelných zdrojů. Fotometrická veličina jas L a spotřeba elektrické energie P byly vyhodnoceny jako vhodné parametry, určující aplikaci ACPEL panelů. Na modrém panelu bylo dosaženo maximální hodnoty jasu L = 133 cd•m2 při napětí Upp = 500 V a frekvenci f = 1000 Hz. Hodnoty spotřeby elektrické energie, vztažené na jednotkovou plochu panelů zkoumaných v této práci, jsou (7±3) mW. Tyto dosažené hodnoty dělají ze světelných zdrojů založených na ACPEL technologii zajímavé kandidáty pro různé aplikace. Vlivu rostoucí amplitudy a frekvence budícího napětí na dlouhodobou stabilitu panelů je důležitým cílem této práce. Pro popis stability byly zavedeny parametry L50 and L75. Bylo zjištěno, že rostoucí frekvence budícího napětí zkracuje životnost panelů. Laminovaný panel napájený napětím s přibližně trojnásobně vyšší frekvencí vykazoval přibližně třetinové hodnoty parametrů L50 a L75. Nejvyšších hodnot stabilitních parametrů dosahoval panel enkapsulován mezi skleněné pláty – přibližně sedminásobnou hodnotu oproti laminovanému panelu s trojnásobnou frekvencí. Optimální stability panelů lze dosáhnout při nastavení frekvence v rozmezí 400–800 Hz a zapouzdřením mezi sklo. Úzká paleta odstínů barev emitovaného světla je jeden z typických problémů, který dále zkoumán v dizertační práci. Tato práce zkoumá nadějnou metodu, přídavek vhodného materiálu pro konverzi barvy (CCM). Nový derivát diketopyrrolopyrrolu (DPP), absorbující v modré oblasti, byl přidán k modrému fosforu a byl pozorován sedminásobný narůst hodnot absolutního spektrálního ozáření v oblasti vlnových délek odpovídajících maximální emisi CCM materiálu. Jednoduchost přípravy vyvinutých zdrojů světla spolu s velmi nízkou spotřebou a vysokou dobou života dělají z ACPEL panelů zajímavé kandidáty pro podsvícení prvků například v automobilovém průmyslu, pro dekorativní osvětlení, pro „branding“ – zvýraznění reklamních značek.
Luminaire position influence on measured parameters in integrating sphere.
Vlček, Pavel ; Škoda, Jan (referee) ; Motyčka, Martin (advisor)
This bachelor thesis deals with the influence of the position of luminaires with narrow radiation characteristics when measured in the integrating sphere. The basic light technical parameters are summarized here. Especially, luminous flux, illuminance, solid angle, luminous intesity and luminance, followed by colour temperature and general colour rendering index. This thesis also deals with the measuring instruments, at first with the basic element, which is the photoelement and then with the following instruments: the illuminance meter, the luminance meter, the spectroradiometer, the goniophotometer and the integrating sphere. The thesis is summarization of the basic information about luminaires. This theory is followed by a laboratory measurement that deals with the measurement of luminaires on a goniophotometer and in the integrating sphere. Goniophotometer measurements are important in conditions of acquire accurate luminous flux. The luminous flux from the goniophotometer is compared with the single measured values in the set positions when measured in the integrating sphere. As a result, the position of the luminaire in the integrating sphere is influenced
Reverse calculation of the luminous intensity curves of street lighting luminaires
Knápková, Dagmar ; Baxant, Petr (referee) ; Škoda, Jan (advisor)
This master´s thesis deals with the reverse calculation of luminous curves for roads according to ČSN EN 13201. The thesis is divided into the theoretical and the practical part. The theoretical part describes the basic requirements and procedures for calculating the luminous curves. The practical part describes the program, created in the Matlab environment, which is designed for the practical calculation of the ideal luminous curve, for each situation given by the user. Further particular example of the calculation is given.
Optimisation of light conditions in buildings
Vajkay, František ; Mohelníková, Jitka (advisor)
Building physics as a branch of architecture must ensure an indoor comfort of each user and inhabitant of a building object. This involves, acoustics, indoor thermal conditions and among others also daylighting and artificial lighting of buildings. Light as a particle and an electromagnetic wave, is required by the different aspects of the human organism. It allows the living beings to see, influences skin and bones, the biorhythms, etc. Therefore, it is necessary for the engineering community to predict the correct illuminance and luminance levels acting insides. The thesis deals with such issues. More precisely, it assesses the quality of design tools and methodologies, either against CIE reference cases described in CIE 171/2006 and against real measurements done over the working plane of an indoor space located in the attic of Building D of the Institute of Building Structures, Faculty of Civil Engineering, Brno University of Technology, too. The tools tested throughout the solution of the dissertation did involve three computer programs: RADIANCE, WDLS v3.1 and WDLS v4.1, and one numerographical approach, namely the Daniljuk’s innovated methodology (sometimes even combined with the theories of BRS). In addition several software’s have had been created alongside the process assessment, just to mention the “RADIANCE Script”, “RADIANCE Data Evaluation Script” or “MuuLUX“. The later was written as a communication software allowing the connection of the KONICA-MINOLTA T10 illuminance meter to a computer with the aim of data collection while long term observation. The solution did also require the establishment of a measuring element for the determination of the light reflectance values of surfaces. The solutions, results and conclusions do describe how well did the design approaches deal while predicting the resulting awaited daylight factor levels in points over the working plane.
Discomfort glare of non-uniform luminaires
Polián, Josef ; Baxant, Petr (referee) ; Škoda, Jan (advisor)
Artificial lighting is an integral part of our everyday life. Nowadays, a large number of people spend practically all their productive time in the presence of the artificial lighting system. This places considerable demands on the quality of this artificial lighting system. One of the indicators of the quality of the lighting system is the evaluation of glare. The UGR evaluation methodology is currently used to evaluate glare. However, the UGR rating has its limitations. These limitations include ambiguous assessments of luminaires with non-uniform luminous surface (so - called non - uniform luminaires). This diploma thesis deals with the issue of discomfort glare of non-uniform luminaires. The aim is to make a literature review of this issue. The first part focuses on theoretical knowledge of glare and its evaluation. Another part is an analysis of recent studies on the topic about glare from non-uniform types of luminaires. The last chapters of the thesis deal with own practical evaluation of glare.
The effect of operating position of the light source on the photometric parameters
Šťastný, Jakub ; Štěpánek, Jaroslav (referee) ; Škoda, Jan (advisor)
The theses discusses how operating position and ambient temperature affect electric light sources. For the purposes of this theses, the analysis of light radiation, the description and the principle of taking measurements of light quantities are included. The work also contains the principle of function, construction and parameters of light sources. For each light source a hypothesized impact of the operating position of the light source and the impact of ambient temperature variation on radiated luminous flux are stated. For selected light sources a measurement of the impact of the operating position on the sources’ photometric parameters was taken. The output measurement data are being compared to the theoretical hypotheses. The conclusion of the thesis describes suggested recommendations for the operation of light sources based on both theoretical and practical parts of the thesis.
Measurement of Operational Parameters of Light Sources
Motyčka, Martin ; Pavelka, Tomáš (referee) ; Krbal, Michal (advisor)
This semestral thesis is focused on description of operating parameters of light sources and their measurements. There are descripted light-technical, electrical and other parameters of light sources and methods of their measurements and evaluations. In tables there are ranges of fotometric quantities for most types of light sources. This thesis is also focused on functional explanation of photometric measuring instruments.
Daylighting of spaces with light guides
Machová, Petra ; Gábrová, Lenka (referee) ; Vajkay, František (advisor)
This thesis deals with the illuminance space through light guide. It describes it's basic principles, technical features and ways of differentiation between the technologies. The thesis also includes latest methods for evaluation of illumination of space supported by various computer simulations.

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