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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
841

Sustainable architectural design between inscription and de-scription : the case of Masdar City

Sharif, Ahlam Ammar Abdellatif January 2016 (has links)
The thesis aims to deconstruct the traditional dualities between design and use and blend the boundaries between them. It characterises design as a process that is complex, dynamic, and integral to other processes, such as use. The thesis utilises Latour's concept of the collective. Although this concept has been applied to architectural contexts in previous studies, this thesis expands the collective to include actors of use. The thesis elaborates on the inscription and description of technologies inspired by Akrich (1992). It shows how the collective is shaped and reshaped through such processes. Building parallels with previous studies, it analyses the importance of fluidity and fluid actors in de-scribing technologies and reshaping the collectives. The thesis utilises the case of Masdar City, which has been designed in the UK by the architectural and urban planning firm Foster + Partners and implemented in the Middle East, specifically in the United Arab Emirates. The thesis focuses on its first developed stage represented by Masdar Institute of Science and Technology (MIST). Based on a qualitative and inductive approach, the conducted research utilises interviews and site observations with the designers, users, and other main contributors. Through this approach, the thesis reflects on the concept of sustainability that is itself contested, changeable, and vague. The thesis concludes that sustainable design processes should be seen as continuous loops between design and use. In acknowledging this, it is further suggested that concepts such as the living laboratory, which support the adaptation of designs and learning from use, are adopted at the outset in architectural production.
842

Improvements to longitudinal clean development mechanism sampling designs for lighting retrofit projects

Carstens, Herman January 2014 (has links)
An improved model for reducing the cost of long-term monitoring in Clean Development Mechanism (CDM) lighting retrofit projects is proposed. Cost-effective longitudinal sampling designs use the minimum number of meters required to report yearly savings at the 90% confidence and 10% relative precision level for duration of the project (up to 10 years) as stipulated by the CDM. Improvements to the existing model include a new non-linear Compact Fluorescent Lamp population decay model based on the results of the Polish Efficient Lighting Project, and a cumulative sampling function modified to weight samples exponentially by recency. An economic model altering the cost function to a nett present value calculation is also incorporated. The search space for such sampling models are investigated and found to be discontinuous and stepped, requiring a heuristic for optimisation; in this case the Genetic Algorithm was used. Assuming an exponential smoothing rate of 0.25, an inflation rate of 6.44%, and an interest rate of 10%, results show that sampling should be more evenly distributed over the study duration than is currently considered optimal, and that the proposed improvements in model accuracy increase expected project costs in nett present value terms by approximately 20%. A sensitivity analysis reveals that the expected project cost is most sensitive to the reporting precision level, coefficient of variance, and reporting / Dissertation (MEng)--University of Pretoria, 2014. / gm2014 / Electrical, Electronic and Computer Engineering / Unrestricted
843

Photonique UV : structuration top-down du ZnO pour une émission amplifiée et un transfert d'énergie efficace / ZnO based UV photonics : enhanced emission and energy transfer through top-down micro and nanostructuring

Nomenyo, Komla Dunyo 18 June 2014 (has links)
Le présent travail de thèse a été effectué dans le cadre du projet CPER-FEDER MATISSE, projet coordonné par l’UTT regroupant deux autres partenaires : Nanovation et l’URCA. Le projet avait pour ambition la croissance des couches minces de ZnO de haute qualité et leur valorisation.Le ZnO cristallin est un semiconducteur à grand gap avec d’excellentes propriétés optiques. Son énergie de liaison excitonique de 60meV est l’une des caractéristiques qui lui valent tant d’attention malgré sa difficile gravure physique qui hypothèque la réalisation de composants photoniques compacts. En effet, la longueur d’onde d’émission du ZnO est de l’ordre de 375nm, impliquant l’utilisation de structures de petite taille dont la réalisation relève des nanotechnologies.Trois objectifs scientifiques ont été poursuivis : l’amélioration de l’extraction de l’émission excitonique dans les couches minces de ZnO par ingénierie de gap en utilisant les cristaux photoniques, l’émission laser et son contrôle et enfin, le transfert d’énergie du ZnO vers les QDots comme couche de phosphores pour la conversion de l’émission UV en lumière blanche. Pour y parvenir, deux technologies ont été utilisées : la croissance PLD (Nanovation) et la structuration par approche top-down délaissée par la communauté scientifique.La thèse traite de la structuration par lithographie électronique combinée à la gravure RIE-ICP et les études scientifiques associées. Les résultats obtenus sont concluants avec parfois des records comme pour le gain (>1000cm-1) et les pertes optiques (<10cm-1). Nous avons également procédé à la réalisation des premiers composants optoélectroniques : laser MIS et photodétecteur MSM / This work was conducted in the framework of the MATISSE project supported by the CPER-FEDER. Coordinated by UTT and including two other partners: Nanovation and URCA, the main project objective was the growth of high quality ZnO thin films and their valorization.ZnO is a wide band gap semiconductor with excellent optical properties. Its exciton binding energy (60meV) is one of the most important characteristics that earned to ZnO more attention despite its physical etching which is difficult to perform. Indeed, the excitonic emission of ZnO occurs approximately at 375nm, which involves the use of small structures whose achievement leads to the use of nanotechnology.Three scientific objectives were pursued: improving the extraction of the excitonic emission in ZnO thin films by engineering the photonic band gap by using photonic crystals, laser emission and control and finally, energy transfer from ZnO to QDots used as phosphors for down conversion of the UV emission to white emission. To achieve this, two technologies were used: PLD growth (Nanovation) and top-down structuring approach neglected by the scientific community.The thesis mainly deals with the structuring by electron beam lithography combined with ICP - RIE and related scientific studies. Conclusive results have been obtained such as high optical gain (>1000 cm-1) and low optical losses (<10 cm-1). We also carried out first optoelectronic components: MIS laser and MSM photodetector
844

Integrate Building Information Modeling (BIM) and Sustainable Design at the Conceptual Stage of Building Projects

Jalaei, Farzad January 2015 (has links)
Lately the construction industry has become more interested in designing and constructing environmentally friendly buildings (e.g. sustainable buildings) that can provide both high performance and monetary savings. Analyzing various parameters during sustainable design such as Life Cycle Assessment (LCA) and energy consumption, lighting simulation, green building rating system criteria and associated cost of building components at the conceptual design stage is very useful for designers needing to make decisions related to the selection of optimum design alternatives. Building Information Modeling (BIM) offers designers the ability to assess different design options and to select vital energy strategies and systems at the conceptual stage of proposed buildings. This thesis describes a methodology to implement sustainable design for proposed buildings at their conceptual stage. The proposed methodology is to be implemented through the design and development of a model that simplifies the process of designing sustainable buildings, evaluating their Environmental Impacts (EI), assessing their operational and embodied energy and listing their potential accumulated certification points in an integrated environment. Therefore, a Decision Support System (DSS) is developed by using Multiple Criteria Decision Making (MCDM) techniques to help design team decides and selects the best type of sustainable building components and design families for proposed projects based on three main criteria (i.e. Environmental, Economical factor «cost efficiency » and Social wellbeing) in an attempt to identify the influence of design variations on the sustainable performance of the whole building. The DSS outcomes are incorporated in an integrated model capable of guiding users when performing sustainable design for building projects. The proposed methodology contains five modules: 1) Database Management System (DBMS), 2) Energy and lighting analysis, 3) Life Cycle Assessment (LCA), 4) LEED and 5) Life Cycle Cost (LCC). To improve the workability of the proposed model, a use case of abovementioned modules are going to be created as plug-ins in BIM tool. The successful implementation of such a methodology represents a significant advancement in the ability to attain sustainable design of a building during the early stages, to evaluate its EI, and to list its potentially earned certification points and associated soft costs.
845

Des plans-lumière nocturnes à la chronotopie. Vers un urbanisme temporel / From urban-lighting to chronotopy. Toward a time-space-planning

Mallet, Sandra 17 November 2009 (has links)
Cette thèse s'intéresse à la prise en compte des rythmes urbains en urbanisme. Alors que les évolutions économiques, sociales et techniques ont progressivement transformé nos rapports à l'espace mais aussi au temps, il nous paraît fondamental de s'interroger sur les enjeux actuels de ces transformations dans le champs urbanistique. Notre regard porte ici sur la nuit, temps particulier de notre quotidien qui subit de nombreux bouleversements. Nous nous attachons aux mutations qui s'opèrent tant aux plans des pratiques spatiales et sociales qu'à celui des représentations. / This thesis is focused on the consideration on urban rhythms in planning. Indeed, faced to economic, social and technical evolutions in France, it's seems now essential to take into account the current stakes of transformations in urban planning.The analysis is centred on night-time, a particular moment of the everyday life, which undergoes numerous changes. The mutations i take into consideration are both social and spatial practices and representations.
846

Identifiering av energianvändningen hos en kontorsfastighet i en svensk tätort : - en fallstudie med beräkningsinslag

Karlsson Falk, Susanne January 2017 (has links)
The current climate changes require a global response immediately. Every year the use of energy increases, which means that more and more greenhouse gases are released. Which in turn helps accelerate global warming. To reduce the energy use will not be an easy task for mankind. Household and service accounts for about 40% of Sweden’s energy use, and office buildings prove to be among the most energyintensive. Previous research shows that heat-, ventilation- and cooling systems along with lightning are the systems that provide the highest energy consumption and that there is also a great savings potential. In this study, the energy use of a property in a Swedish urban area has been investigated and how the energy is being used by the different systems has been identified. The purpose of this research is to see which measures can give the greatest cost-effective savings. Method used is a case study, which was an energy survey, combined with a literature review of relevant information. Data collection consisted of information from the property owner,inspection of the building and electricity measurements. The result shows that there are great savings to be made. If proposed measures are implemented (see section 4.6), energy consumption for heating can be reduced by 144,9 MWh/year or 32,4%. Energy used by lightning can be reduced by 46,8 MWh/year or 40,3%and other measures can be reduced by 41 MWh/year or 53%. Measures that can be performed for free were considered the most cost-effective, such as lowering the indoor temperature or turning off equipment between days. For measures with investment cost, isolation of the attic was considered most cost -effective with a payoff time of 5 years. To invest in sun cells would reduce the bought electricity with 56,8 MWh/yr. Due to lack of information, assumptions and simplifications were made that could have caused sources of error.
847

Desenvolvimento de um sistema de gestão de iluminação pública através de redes de sensores e atuadores sem fio = Development of a street lighting management system based on wireless sensors and actuators networks / Development of a street lighting management system based on wireless sensors and actuators networks

Della Lucia, Felipe Lorenzo, 1984- 26 August 2018 (has links)
Orientador: Leandro Tiago Manera / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-26T15:58:55Z (GMT). No. of bitstreams: 1 DellaLucia_FelipeLorenzo_D.pdf: 3577549 bytes, checksum: 4c1aa6af60e58052accce7e28ad2c314 (MD5) Previous issue date: 2014 / Resumo: Este trabalho apresenta o desenvolvimento de um sistema sem fio de gestão de iluminação pública. Através do sistema desenvolvido, é possível controlar a potência de cada lâmpada de vapor de sódio de alta pressão dos postes de iluminação pública de determinada região. Desta maneira, nos horários em que as vias públicas se tornam menos utilizadas, é possível reduzir a potência e o brilho das lâmpadas e economizar energia elétrica. O sistema proposto utiliza o protocolo ZigBee para realizar a comunicação sem fio entre os módulos instalados nos postes. Este protocolo é baseado no protocolo IEEE 802.15.4 desenvolvido especialmente para redes de sensores sem fio e foca em baixo consumo de energia e transmissão da informação nó a nó da rede. Também é possível instalar sensores (luminosidade, umidade, etc.) nos módulos projetados e transformar cada unidade de iluminação pública em uma central de monitoramento de determinada região. Os resultados mostram que o sistema economiza energia, sendo possível reduzir a potência das lâmpadas em até 60% sem que o fator de potência do reator saia do valor mínimo estipulado na regulamentação (0,92). Os módulos desenvolvidos dão a opção ao operador de escolher a potência das lâmpadas em três valores distintos: 100%, 80% e 50% da potência nominal, sendo possível alterar estes valores conforme a necessidade do operador e do local onde o sistema será utilizado (condições de tráfego e segurança). O sistema foi testado em laboratório e em campo, em postes da Universidade Estadual de Campinas, onde ficou instalado pelo período entre 05/02/2014 e 01/04/2014. A potência das lâmpadas foi variada e medidas de iluminância e uniformidade foram realizadas na via. Foi possível concluir que o sistema é robusto, imune a interferências eletromagnéticas da rede de distribuição, e dá flexibilidade aos ajustes de iluminância e uniformidade de iluminação da via. O alcance de nó a nó da rede é, em média, de 260 m, o que torna a utilização do protocolo e do circuito desenvolvido adequados para esta aplicação, uma vez que a distância típica entre postes é de 30 a 40 metros. Estudos de viabilidade econômica foram realizados e mostram que o sistema é viável e apresenta taxas de retorno atrativas que dependem fortemente da tarifa de energia vigente / Abstract: This project presents the development of a wireless system for public street lighting management. Through the developed system, it is possible to control the power of each high pressure sodium lamp of the streetlights in a particular region. Thus, at times when the public streets become less utilized, it is possible to reduce the power and brightness of the lamps and save energy. The proposed system uses the ZigBee protocol to perform wireless communication between the modules installed on the lampposts. This protocol is based on IEEE 802.15.4 protocol, developed especially for wireless sensors networks and focus on low power consumption and data transmission node to node. It is also possible to install sensors (luminosity, humidity, etc.) in the designed modules and transform each unit of public lighting in a region into a monitoring station. The results show that the system saves energy and it is possible to reduce the lamp power by 64%, without reducing the ballast's power factor below the value stipulated in the regulation (0.92). The developed modules give the operator the option to choose the lamp power between three distinct values: 100%, 80% and 50% of rated nominal power, and it is also possible to change these values according to the operator's needs and the installment place characteristics (traffic usage, security). The system was tested in laboratory and on field, on the lampposts at State University of Campinas, where it remained installed in the period between February 5th and April 1st of 2014. The lamp power was varied and measurements of illuminance and uniformity were performed on the street. It was possible to conclude that the system is robust and immune to electromagnetic interference from the energy distribution grid, and gives flexibility for adjustments of brightness and uniformity of the street lighting. The reach node to node of the network is, on average 260 m, which makes the protocol and developed circuit adequate for this application, since the distance between lampposts is typically 30 to 40 meters. Economic viability studies have been conducted and show that the system is feasible and present attractive rates of return that depend heavily on the rate of current energy price / Doutorado / Eletrônica, Microeletrônica e Optoeletrônica / Doutor em Engenharia Elétrica
848

Sistema inteligente para monitoração, gerenciamento e controle de iluminação pública e análise de parâmetros da rede elétrica

Pinto, Milena Faria 22 June 2015 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-01-07T18:22:40Z No. of bitstreams: 1 milenafariapinto.pdf: 3767169 bytes, checksum: 1c057d68b3cee498c456fe7c7610b2c2 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-01-25T16:53:33Z (GMT) No. of bitstreams: 1 milenafariapinto.pdf: 3767169 bytes, checksum: 1c057d68b3cee498c456fe7c7610b2c2 (MD5) / Made available in DSpace on 2016-01-25T16:53:33Z (GMT). No. of bitstreams: 1 milenafariapinto.pdf: 3767169 bytes, checksum: 1c057d68b3cee498c456fe7c7610b2c2 (MD5) Previous issue date: 2015-06-22 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O presente trabalho propõe um sistema eletrônico que permite gerenciar, monitorar parâmetros e controlar de forma descentralizada um conjunto de luminárias à LED pertencentes a um sistema de iluminação pública. Estes parâmetros incluem nível de iluminação, consumo de energia, detecção da presença de pedestres, problemas na própria luminária e monitoração de variáveis ambientais como temperatura e umidade. Adicionalmente, o mesmo sistema é capaz também de detectar falhas na rede elétrica, permitindo monitorar e gerenciar os parâmetros de qualidade de rede de uma forma global. Basicamente, o sistema pode ser dividido em três partes. A primeira parte consiste de um módulo inteligente, chamado neste trabalho por SM, que é conectado a uma determinada luminária e à rede elétrica, sendo assim responsável por medir tanto os parâmetros provindos da luminária quanto da rede elétrica. Na segunda parte encontra-se o módulo controlador (CM) que possui a finalidade de coordenar as informações oriundas dos módulos inteligentes instalados nas luminárias, armazenando e posteriormente enviando os dados para um sistema supervisório. Além disso, o mesmo possui sensores de temperatura e umidade para prover informações sobre as condições climáticas, objetivando confiabilidade nos dados medidos pelos sensores dos módulos inteligentes. O sistema supervisório (SS) consiste da etapa final deste sistema proposto, o qual é responsável por salvar os dados obtidos em um certo período de tempo, analisar e monitorar possíveis falhas e enviar comandos para cada CM e/ou um respectivo SM. Com a finalidade de avaliar experimentalmente o sistema proposto neste trabalho, foram realizados experimentos para demonstrar tanto as funcionalidades do módulo bem como da avaliação dos algoritmos de processamento de sinais propostos, e obtendo ao final projeções econômicas para o protótipo. Os resultados obtidos mostraram eficiência, flexibilidade e interoperabilidade do sistema proposto. / The present paper proposes a system to manage, control and monitor a group of LED luminaires of a street lighting system, being able to control the light intensity of the luminaire and monitoring the power consumption, detection of pedestrians, fault conditions, environmental parameters such as temperature and humidity. Additionally, the system contains a voltage sensor coupled to the grid in order to monitor and manage the power quality parameters. Basically, the system can be divided in three essential parts. The first one regards the smart module, called in this work as SM, which has the responsibility to sensing the parameters stemming from power grid as well as luminaire. The second part is the control module (CM), which has the aim to coordinate the data received from each smart module, storing and subsequently sending the data to the supervisory system. Besides, the control module also has temperature and humidity sensors in order to check and register environmental conditions, providing, in this way, reliability of the measured data. The supervisory system (SS) consists of the final part of the proposed system and it is responsible to save the data in a local memory, to analyze and to monitor problems or even possible faults and sending commands to each CM and/or a respective SM. With the aim to evaluate the proposed system, it was performed experiments to demonstrate the system operation as well as the quality analysis capability. Due to the energy savings potential provided by the technology, it was also studied the economic feasibility of the prototype, aiming a future commercial product. The results have shown that the proposed system is scalable, flexible and efficient.
849

Akcelerace výpočtu stínů a osvětlení / Shadowing and Lighting Acceleration

Milet, Tomáš January 2021 (has links)
Cílem této práce je prezentovat metody pro akceleraci výpočtů stínů a osvětlení.  Práce se zabývá akcelerací na vzorek přesných stínů pomocí stínových těles na různých platformách. Obsahem práce je také zvýšení přesnosti stínových map a zvýšení přesnosti osvětlování scény s mnoha světly.
850

ATMOSFÄRSSKAPANDE LJUS I MUSEUM OCH KONSTHALL : En studie om samspelet mellan ljus och rumslighet / ATMOSPHERE CREATING LIGHT IN MUSEUM AND ART GALLERY SPACES : A study about the interplay between light and spatiality

Bichsel, Benjamin, Åsell, Stina January 2021 (has links)
A lot of research on the experience of atmosphere uses physical measurements. However, a recognised idea among lighting designers is that these physical values and the experience of light is not always the same, which makes it relevant to work more with visual observations to understand and analyse spatiality and the effects of light. The purpose of the study was to investigate how spaciousness and atmosphere in museum and art gallery environments can be linked to their lighting and art. This is to provide an increased understanding of how light affects spatiality and how it relates to the room’s atmosphere, and to be able to see how the atmosphere is experienced in connection with the exhibits. The study was conducted through visual observations during site visits, for each evaluated room at each museum and art gallery. The rooms were analyzed using the PERCIFAL and Branzell methods, but the values of illuminance, color temperature, color rendering index, and spectral power distribution were also documented. Additionally, an online survey was sent out to collect further data concerning the experience of atmosphere. Part 1 was quantitative and focused on atmosphere words and was judged on a 7-point scale, while Part 2 was qualitative and focused on the connection between the exhibited object and the room. Here, the respondents responded in text form. The result of the study shows that the experience of atmosphere is affected by the interplay between light and spatiality, and that it is not one lone parameter that is decisive. The respondents thought that an interplay between atmosphere and the exhibited object could elevate the experience of art, and that light was a big part of how the room and its atmosphere was experienced. This shows that there are opportunities to work more with lighting in gallery spaces to create an atmosphere that connect more with exhibitions and objects. The study was limited to art-related exhibitions in Sweden. Due to the study was conducted in a very specific context it can not be said with certainty to be generally valid, though parts of the result pertaining to the atmosphere affecting parameters are likely able to use in other situations. / Mycket forskning om atmosfärsupplevelse använder sig av fysikaliska mätningar. En vedertagen idé bland ljusdesigners är dock att fysikaliska värden och det upplevda ljuset inte alltid är detsamma, vilket gör att det blir relevant att arbeta mer med visuella observationer för att förstå och analysera rumslighet och ljusets påverkan. Syftet med studien var att undersöka hur rumslighet och atmosfär i musei- och konsthallsmiljöer kan kopplas till deras belysning och konst. Detta för att ge en ökad förståelse kring hur ljuset påverkar rumsligheten och hur det anknyter till rumsatmosfären, samt att kunna se hur atmosfären upplevs i anknytning till utställningsföremålen. Studien utfördes genom visuella observationer under platsbesök i respektive rum för varje museum och konsthall. Rummen analyserades genom metoderna PERCIFAL och Branzellmetoden, men även fysikaliska värden som belysningsstyrka, färgtemperatur, färgåtergivning och spektralfördelning dokumenterades. Slutligen skickades en digital enkät i två delar ut. Del 1 var kvantitativ och fokuserade på atmosfärsord och bedömdes på en 7-gradig skala, medan Del 2 var kvalitativ och fokuserade på kopplingen mellan utställningsföremålet och rummet. Här hade respondenterna möjligheten att svara i textform. Resultatet i studien visar att atmosfärsupplevelsen påverkas av samspelet mellan ljus och rum, och att det inte är en enskild parameter som avgör. Respondenterna ansåg att ett samspel mellan atmosfär och utställningsföremål kunde förhöja upplevelsen av konst och att ljus hade en tydlig påverkan för hur rummet och dess atmosfär uppfattades. Detta visar på att det finns möjligheter att arbeta mer med ljus i utställningslokaler för att skapa en atmosfär som samspelar mer med utställningar och utställningsföremål. Studien har begränsats till enbart konstutställningar på museer och konsthallar i Sverige. Utifrån att detta arbete genomfördes i denna specifika kontext kan det inte med säkerhet sägas vara generellt giltigt, men vissa delar av resultatet kring de atmosfärspåverkande parametrarna är sannolikt möjliga att överföra i andra situationer.

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