FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / With global need to reduce energy consumption, the search for more efficient technologies has become the focus of many studies. Among these technologies, it can mention the photovoltaic solar energy and LEDs, which have shown an expansion in recent decades. Photovoltaic generation is shown as an attractive energy source because it is renewable and its raw material is practically inexhaustible. While LEDs have a promising advance in lighting and is used in several applications. To integrate these technologies, this paper proposes the study of a DC-DC step-up switched-capacitor (SC) converter for LEDs applied to photovoltaic stand-alone systems. The proposed circuit differs from other topologies SC to insert an inductor in series with the input source, which can operate in discontinuous conduction mode (DCM), reducing losses switching, or continuous conduction mode (CCM), allowing the reduction of conduction losses in the circuit. The converter is driven by the frequency modulation, which is obtained as a function of input voltage. For this reason, the current in the LEDs can be stabilized without the need for sensor or feedback. The prototype developed in the laboratory was designed for a lamp of 54 W and operating at high frequency (up to 165 kHz), allowing the reduction of the circuit volume. Experimental results of the circuit in DCM and CCM show that the converter has a high yield, validating the proposal. / Tendo em vista a tendÃncia da reduÃÃo do consumo de energia no mundo, a busca por tecnologias mais eficientes tem se tornado o foco de muitos estudos. Dentre estas tecnologias, pode-se citar a energia solar fotovoltaica e os LEDs, que vem apresentando uma expansÃo nas ultimas dÃcadas. A geraÃÃo fotovoltaica se mostra como uma atrativa fonte de energia, por ser renovÃvel e sua matÃria-prima ser praticamente inesgotÃvel. Enquanto os LEDs apresentam um avanÃo promissor na iluminaÃÃo, sendo utilizado nas mais diversas aplicaÃÃes. Visando a integraÃÃo destas tecnologias, este trabalho propÃe o estudo de um conversor CC-CC elevador com capacitor comutado (Switched Capacitor - SC) para LEDs, aplicado a sistemas fotovoltaicos autÃnomos. O circuito proposto se difere de outras topologias SC por inserir um indutor em sÃrie com a fonte de entrada, o qual pode operar no modo de conduÃÃo descontÃnua (MCD), reduzindo as perdas por comutaÃÃo, ou no modo de conduÃÃo contÃnua (MCC), possibilitando a reduÃÃo das perdas por conduÃÃo do circuito. O conversor à acionado atravÃs da modulaÃÃo por frequÃncia, a qual à obtida em funÃÃo da tensÃo de entrada. Por este motivo, a corrente nos LEDs pode ser estabilizada sem a necessidade de sensores ou de realimentaÃÃo. O protÃtipo desenvolvido em laboratÃrio foi projetado para uma luminÃria de 54 W e operando em alta frequÃncia (atà 165 kHz), possibilitando a reduÃÃo do volume do circuito. Os resultados experimentais obtidos do circuito MCD e MCC sÃo analisados e validam a proposta, mostrando que o conversor apresenta rendimento elevado

The implementation of energy policies oriented to incentive the adoption of efficient lighting technologies in the residential sector requires analytic tools able to describe the market conditions necessary for a successful penetration of the innovations. This article describes, using an agent-based model, the relationship between the micro behaviors of householder\'s adoption of lighting technologies and the aggregated macro patterns of diffusion in the Brazilian residential sector. The model also studies the dynamic between the interaction network parameters and the emerging diffusion characteristics in different economic scenarios for energy and technologic prices / A implementação de políticas públicas orientadas a incentivar a adopção de tecnologias de iluminação mais eficientes no setor residencial precisa de ferramentas analíticas capazes de descrever assertivamente as condições de mercado necessárias para uma penetração exitosa destas inovações. Este documento descreve, utilizando modelagem baseado em agentes, a relação entre os micro comportamentos dos usuários ao adotar as tecnologias de iluminação e as macro tendências agregadas de difusão no setor residencial brasileiro. O modelo também estuda a dinâmica existente entre a relação dos parâmetros das redes de interação e as caraterísticas emergentes no processo de difusão em diferentes cenários econômicos para os custos energéticos e tecnológicos.

Les diodes électroluminescentes (LEDs) constituent de nouvelles solutions pour créer des luminaires plus robustes, ayant un meilleur rendement de conversion et plus respectueuses de l'environnement. Malgré les avantages indiscutables déjà obtenus aujourd'hui, ce type de luminaire présente encore quelques optimisations possibles et offre des possibilités de fonctionnalités multiples. A travers plusieurs campagnes de tests, l'auteur montre sur des LEDs du commerce, que les points d'optimisation non encore exploités dans les luminaires commerciaux. Ces LEDs ont ainsi été testés sur de larges plages de fonctionnement du point de vue photométrique, électrique mais aussi thermique pour connaitre la reproductibilité des résultats obtenus. Ainsi les influences des conditions d'utilisation notamment en température de fonctionnement et niveaux de courant d'alimentation ont été étudiées. Pour dimensionner au mieux une alimentation électrique spécifique, une recherche de modèles de LED élémentaires a été effectuée. L'objectif est que les modèles tiennent compte des principaux paramètres mais soit suffisamment simple pour être inséré dans un environnement système afin de simuler le luminaire dans son environnement complet. Ainsi, l'étude comparative de plusieurs associations de LEDs a été effectuée permettant d'en déduire des compromis pour proposer de nouvelles solutions faibles consommatrices d'énergie à coût réduit incluant de nouveaux types d'alimentation. / Light emitting diodes (LEDs) bring new possibilities to get luminaires more robust with an improved efficiency and more environmentally respectfull. Despite the benefits already achieved today, this type of luminaire still presents some possible optimizations and provides opportunities for multiple features. Through several tests, the author shows on LEDs in market that optimization points are not operated in commercial luminaires. These LEDs have been tested over a wide range of operation in photometric, electrical but also thermal to know the reproducibility of the results. Thus the influences of operating conditions including operating temperature and supply current levels were studied. To design a specific power supply for each LED type, a search of elementary LED models was performed. The objective is to take into account the main parameters of the models but also to be enough simple to be inserted into a system environment to simulate the luminaire in whole environment. Thus, the comparative study of several associations of LEDs was conducted to deduce the best compromise and propose new solutions to reduce energy consumptions and production costs, including new types of power supply.

Esta pesquisa aborda a depreciação da tecnologia LED comparada à da tecnologia fluorescente nos sistemas de iluminação mais utilizados em ambientes corporativos internos. O resultado da depreciação dos sistemas de iluminação foi obtido por meio da experimentação em uma célula teste, com dois modelos de luminárias (com aletas e com difusor) e três fontes de luz: a tradicional lâmpada fluorescente tubular T5 de 28W, o tubo LED T8 de 18W e LED aplicado sobre a luminária. Os conjuntos foram instalados na célula teste e ficaram ligados por aproximadamente 17.000 horas. As medições foram realizadas a cada 3 meses ao longo de 24 meses (2 anos) com um luxímetro em pontos definidos, de acordo com a norma NBR/ISO 8995:2013. Juntamente com as medições, os sistemas de iluminação foram ensaiados em laboratório acreditado pelo INMETRO em dois momentos. O primeiro ensaio ocorreu com os sistemas de iluminação em zero hora, e o segundo após a depreciação de todos os sistemas de iluminação utilizados na pesquisa. Adicionalmente, foram realizadas simulações computacionais para posterior comparação dos resultados entre simulação e experimentação. Os programas de simulação utilizados foram o Dialux EVO, o Relux e o AGi32. Para verificar as hipóteses da pesquisa, os resultados das medições foram comparados com os valores de fator de manutenção resultantes, conforme norma CIE-97:2005. / This research compares the depreciation of LED technology with fluorescent technology, considering the most commonly used lighting systems in internal corporate environments. The result of the depreciation of these lighting systems was obtained by experimenting inside a testing room, with two models of luminaires - with fins and with diffuser - and three light sources: the traditional T5 tubular fluorescent lamp of 28W, the T8 LED tube of 18W and LED applied over the luminaire. These sets were assembled in the test cell and kept on for approximately 17,000 hours. Measurements were performed every 3 months over 24 months(2 years) using a luximeter. The placement of the testing points were defined according to the NBR/ISO 8995:2013 norm. At the same time, the lighting systems were tested in a laboratory accredited by INMETRO in two distinct moments. The first experiment was done with all lighting systems at zero hour and the second after the depreciation of all lighting systems used in the research. In addition, computational simulations were performed for later comparison of the results between simulation and experimentation. The simulation programs used were Dialux EVO, Relux and AGi32. To verify the hypothesis of this research, the results of the evaluations were compared to the values of the maintenance factor according to the CIE-97:2005 norm.

LED(Light Emitting Diode，發光二極體)的應用已由最早的數字顯示器和指示器發展出一些新的應用，與生活息息相關，四處可見，包括出口指示燈、裝飾燈、交通號誌、舞台燈、室外照明和投射燈等。LED提供的好處包括體積小、使用壽命長、低熱量輸出、節約能源和耐用性，它也擁有設計的靈活性，譬如由將小單體封裝成不同的形狀、顏色、大小及亮度可以達到顯色及調光的各種不同變化。但是LED技術發展限制使得它在整體光源輸出、演色性及可靠性仍不如規格宣稱可以達到的境界，因此在某些應用上還不普及，尤以取代傳統照明的應用市場目前較難達成。然而其餘LED在包括零售展示，彩色燈光，需要較暗光線的狹小空間照明，外部照明和應用一體化的光源的建築、娛樂與劇場照明等應用領域已經漸漸形成市場。由於台灣基於半導體產業的興盛，讓LED產業也隨之蓬勃發展起舞。 Philips公司進入LED照明產業後，積極地展開規劃佈署，主以併購的方式，於2005至2009年共併購了9間LED照明相關公司。從上游研發與製造LED晶片與元件公司Lumileds，到中游LED照明控制廠商Color Kinetics、TIR system、Bodine與Dynalite，以及下游LED燈具製造商PLI、Genlyte與Selecon，將LED照明產業鏈上的的關鍵公司納入旗下，對本身LED照明產品線進行垂直整合以及組織重整，Philips公司藉此以大規模的併購動作向全球宣告自身於LED照明產業的龍頭地位。 本研究針對LED照明產業作一系列的探討與分析，先從目前LED照明發展概況、主要廠商LED照明產品技術結構分析開始作初步探討，最後以Philips公司為個案探討該公司在LED照明的商業模式，如在LED照明產業的組織設計、投資、併購、合資、研發、授權與專利佈局…等。透過上述分析資料及結果，本研究歸納出Philips公司於LED照明產業的經營模式與發展策略，並對應到台灣企業目前的發展狀況。對台灣企業發展LED照明而言，當務之急除致力技術研發，累積自身專利之保護傘，以及對國外廠商的大規模授權動作亦必須要進行充分的研究與了解外，仍需借鏡Philips公司經營LED照明產業的方法與經驗，重新規劃自身的商業模式與競爭策略，避免重蹈過往台灣廠商在LED晶粒與封裝段遭遇的困境，逃脫不了向國外大廠取得授權或是被告的命運。 / The application of LED (Light Emitting Diode) evolved from digital display and indicators to more utility devices close to daily life, such as indicator lamps, decorative lamps, traffic lights, stage lights, outdoor lights, and projection lights. The limit of current technology restricts LED from so-claimed full performance concerning global illumination, color rendering, and reliability so that it is less available in certain applications, especially in the market of traditional lightings. However, LED becomes popular in retail display, color lighting, illumination of a small space, exterior lighting, illumination of integrated building, entertainment lighting and stage lighting. In addition, the prosperity of Taiwan semi-conductor industry encourages the development of LED industry in Taiwan. The LED companies have developed into a complete industry chain in Taiwan and will play an important role in the global LED industry. Philips aggressively merged 9 LED companies between 2005 and 2009. These companies ranges from upstream to downstream of the LED industry chain, including LED chips manufacturer Lumileds, LED controller companies Color Kinetics, TIR System, Bodine, Dynalite, and LED module and system manufacturer PLI, Genlyte, Selecon. The strategy of Philips is to complete its LED product line through vertical merger and reorganization of these important LED companies, proclaiming its leading position in global LED industry. This thesis begins with an introduction about the latest development of LED lighting and the technology analysis on LED products of the main companies. Further, the thesis will take Philips as the case study to elaborate its business model in LED lighting, such as organization, investment, merger and acquisitions, joint venture, R&D, licensing and patent strategy. Through the analysis on Philips’ business model and strategy in LED industry, the research will propose some suggestions for Taiwan LED companies. Taiwan LED companies should increase their own R&D energy, strengthen their intellectual property and keep up with the updated status of international licensing events. They should also take Philips as an example to examine their own business strategy in case that they may be trapped between high Royalties or lawsuits to international enterprises, a dilemma which Taiwan LED die and package companies encountered.

<p>To give a realistic impression in a driving simulator for nighttime driving, there are many challenging aspects to consider. One of the most important aspects is the illumination caused by the headlights of the own vehicle. To give a realistic impression there is the need to consider the characteristics of the headlight in use to be able to represent main and dipped beam, but also to represent different models and types of headlights. </p><p>Another important aspect is the dazzling effects caused by the light cast by other vehicles upon the driver. These effects are not only important to give a realistic and visually appealing simulation, but also to simulate blinding effects which may affect the drivers ability to perceive the traffic environment to a large degree. </p><p>This thesis describes methods to simulate these vital aspects of night-drive simulation in real-time using the capabilities of today's graphics cards.</p>

<p>What makes an image photorealistic and how to pinpoint and understand how our mind interprets different elements in an image conditions? It is proposed that the phrase "imperfect makes perfect" is the key for the photorealistic goal in today’s 3D. There is a review of all the elements for the creation of one perfect image, such as Global Illumination, Anti-Aliasing and also a basic review of photography, how a scene is set up, color temperature and the nature of the real light. To put different theories to a test, the common three dimensional software 3D Studio Max was used with the V-Ray renderer. On a field trip to IKEA communications, we were assigned a project of a room scene containing a kitchen, with a finished scene model. A kitchen was created and experimented to reach a result where there is no visible difference between a computer generated image and the photography. Our result was not what we had hoped for due to many problems with our scene. We ourselves see this as a first step toward a scientific explanation to photorealism and what makes something photorealistic.</p>

This doctoral thesis deals primarily with condition assessment of road equipment. The road equipment concept is defined by five main groups, road lighting, fences and barriers, vertical signs, horizontal signs and traffic signals, respectively. Of these groups, road markings, street lighting and barriers of three-lane roads have been studied more in detail. A state-of-the-art, comprising information obtained by comprehensive literature studies on condition assessment of road equipment is presented. Comparably few fundamental studies were found, which, to some degree, can be explained by the lack of suitable physical measurement methods. However, in the case of road marking retroreflectivity, mobile instruments have been developed, and research published in this area is relatively comprehensive. Furthermore, although not based on mobile measurements, several studies on assessments on performance of road sign sheeting have been published. The experimental part of the thesis is divided into four studies, of which two are dealing with mobile measurement of wet road markings and street lighting, respectively. One of the studies concerns condition assessment of road marking performance accomplished in the Nordic countries. Finally, one study comprises risk analysis related to crashes into the barriers on three-lane roads. At road equipment condition assessment, mobile measurement methods are preferable compared to stationary methods. However, many relevant parameters are tricky to measure at speed. One example in this connection is characterization of performance of wet road markings, which has to be based on one or more parameters obtained by measurements on dry surfaces. Results presented in this thesis indicate that retroreflectivity and skid resistance of wet road markings can be predicted based on retroreflectivity and macro-texture of dry road marking. For traffic safety, street lighting is important. The performance of this type of road equipment is in most cases described in terms of luminance of the illuminated road surface. However, luminance measurements are tricky and time-consuming and not useful for condition assessment. On the contrary, measurement of illuminance is easy to carry out and can be performed at speed. One part of the thesis describes how road surface luminance in street lighting can be estimated based on illuminance and reflection properties of the road surface. With the purpose of comparing road marking performance in the Nordic countries, condition assessment using mobile measurement equipment was accomplished in 2002 and 2003. In each of the five Nordic countries, a number of roads were chosen for measuring retroreflectivity. The study showed that the retroreflectivity of edge, centre and lane lines was poor in some countries, but, at least regarding edge lines, this shortcoming could be compensated by use of wide, continuous lines. In other words, the visibility of longitudinal road markings was approximately equal in the different countries. The purpose of the risk analysis performed on three-lane road barriers was to estimate the influence of the time-period between initial crash and repair on the risk of a secondary accident. The result showed that, especially in winter-time, time-reduction means reduced risk of secondary accidents. / QC 20100824

Purpose To investigate the possibility to reduce the number of failures caused by moisture and dust ingress in lighting equipment by looking towards customer acceptance and warranty claims, and then translate the result to technical attributes. Methodology The methodology is set up to be a part of a Design for Six Sigma project including the steps up to Concept development and business/customer approval. Known product development tools are used to evaluate existing techniques and generate new concepts. Customer analysis is done by surveys and investigating warranty claims. Result &amp; Conclusions The customer analysis in this thesis show that Brazil and to some extent UK is the countries where the problem is seen as most severe. It also shows that complaints regarding dust are far more common than complaints regarding moisture when it comes to lamps placed at the lower part at the front of the truck. When the results from the customer analysis are compared with the technical aspects it shows that the most beneficial way to deal with the problem is to create a good air flow while still keeping the pore size, which could be done by using membranes and the help from CFD (Computational Fluid Dynamics) simulations. Trapping solutions are also welcomed by the customer as long as they can be part of the regular service. / Syfte Att undersöka behov och möjligheter att reducera problem med fukt och damminträngning i exteriöra belysningsartiklar på lastbilar genom att titta på kundacceptans och garantiärenden samt översätta detta till tekniska attribut. Metod Arbetet är upplagt som en del av ett Design for Six Sigma-projekt och innefattar stegen fram till Concept development and business/customer approval. Kända produktutvecklingsverktyg används för att ta fram underlag till konceptgenerering. Kundanalys utförs med hjälp av enkäter och undersökningar av garantiärenden. Resultat &amp; slutsats Kundanalysen i denna examensrapport visar att Brasilien och Storbritannien är de länder där problemet uppfattas som störst. Den visar också att klagomål gällande damm är mycket vanligare än klagomål gällande fukt när det gäller lyktor placerade i den nedre delen i fronten på lastbilen. När resultaten från kundanalysen jämförs med de tekniska aspekterna finner man att det mest gynnsamma sättet att ta sig an problemet är att försöka få bra ett bra luftflöde i lyktorna men samtidigt minimera porstorleken. Detta kan man åstadkomma med hjälp av membran och CFD (Computational Fluid Dynamics) simuleringar. Lösningar som handlar om att fånga upp dammet och fukten accepteras också av kunden så länge som detta kan lösas med hjälp av den vanliga servicen.

Nowadays, lighting represents 20% of the global electricity consumption. Light can be produced using different technologies but more than 100 years after its invention, the incandescent bulb is still the most sold and one of the more used light sources. Of the total energy input in an incandescent bulb more than 90% is lost as heat while less than 10% is converted into visible light. However, there are alternative technologies which use up to 85% less energy for conventional lighting and there are even more efficient light sources for other purposes that if they replace completely all incandescent lamps over the world could reduce dramatically the global electricity consumption and greenhouse gases emissions. One may identify these alternative technologies mainly as LEDs and discharge lamps, but are they the unique alternatives? This thesis is focused on a new lighting technology whose name is LightLab and which is based on the field emission and cathodoluminescence concepts. This technology is under the research and development stage but prototypes have already achieved energy savings over 85% compared to incandescent lamps with a great color performance and with the advantage that it does not use mercury or other hazardous substances compared with discharge lamps. Thus, in the first part of the project all technologies and last improvements are studied while the second part analyses the market applications possibilities for the LightLab lamp considering the environmental perspective regulations and comparing the lamp with the other light sources. The result is that despite there are still some unknown parameters that need to be developed or improved, the lamp has a great potential for different applications fields.