As cortinas verdes caracterizam-se pelo plantio e desenvolvimento de uma vegetação trepadeira, com auxílio de suportes, posicionada em frente e afastada das superfícies verticais da edificação. Seu aspecto funcional mais relevante está associado à capacidade de proporcionar sombra, atuando como dispositivo de controle solar em arquitetura. Diferente dos sistemas convencionais, o uso da vegetação apresenta benefícios em termos de desempenho, na medida que responde de forma dinâmica às variações do clima e das estações, além de ser um elemento natural e de baixo impacto ambiental, o que vai ao encontro às premissas de uma arquitetura mais sustentável. Desta forma, o objetivo principal desta tese consiste no estudo da aplicabilidade das cortinas verdes como elemento de controle solar em arquitetura, com ênfase em sua contribuição para a eficiência energética de edificações, no contexto climático brasileiro. Para tanto, primeiro foi realizado o embasamento e a discussão teórica sobre o tema, reforçando sua pertinência e relevância, observando o atual estado da arte das pesquisas científicas na área e apresentando exemplares arquitetônicos executados com as cortinas verdes. A seguir, um estudo experimental foi conduzido, com vistas a gerar parâmetros médios sobre a capacidade de sombreamento de quatro diferentes espécies trepadeiras, determinando o Percentual de Transmissão Solar em cada mês, durante um ano de avaliação. Por fim, foram realizadas simulações computacionais de eficiência energética em uma edificação genérica de escritórios, utilizando os dados originados no experimento e comparando o desempenho das cortinas verdes com outros sistemas de sombreamento convencionais. Os resultados do experimento demonstraram o comportamento dinâmico e particular de cada espécie no que diz respeito à capacidade de proporcionar sombra, dependendo da época do ano e de suas características formais. Já quanto aos dados obtidos com as simulações, a maioria dos resultados foi favorável ao uso das cortinas verdes no controle solar da edificação, resultando em economia de energia para refrigeração ou aquecimento artificial, dependendo da região climática e da espécie considerada. Assim, as principais conclusões desta pesquisa estão relacionadas ao potencial positivo do uso das cortinas verdes em arquitetura, atendendo ao duplo propósito da funcionalidade e da expressão formal. As espécies de trepadeiras apropriadas dependerão de cada região, embora, de uma forma geral, as decíduas serão mais favoráveis em climas com estação quente e fria, enquanto as perenes serão mais adequadas para uso em edificações de climas com predomínio de altas temperaturas o ano todo. / Green curtains are characterized by planting and development of climbing vegetation, by the use of supports, positioned in front of vertical surfaces of a building and away from these. Its most important functional aspect is associated to the ability to provide shade, acting as a solar control device in architecture. Different from conventional systems, the use of vegetation shows benefits in terms of performance, as it responds dynamically to changes in climate and seasons, besides it is a natural and low environmental impact element, which is coherent regards to the assumptions of a more sustainable architecture. Thus, the main goal of this thesis is the analysis of the applicability of green curtains as solar control element in architecture, with emphasis on their contribution to the energy efficiency of buildings in the context of Brazilian climate. For this, first of all it has been accomplished the theoretical basement and discussion on the subject, by enhancing its relevance and pertinence, observing the current context of scientific research in the area and presenting architectural projects executed using green curtains. After, an experimental analysis was conducted in order to generate mean parameters on the ability of shading of four different species of climbing plants, determining the Solar Transmission Percentage in each month during a year of observing. Finally, computer simulations of energy efficiency were executed in a generic office building, using data derived in the experiment and comparing the performance of green curtains with other conventional shading systems. The results of the experiment demonstrated the dynamic and particular behavior of each species in relation to the ability of providing shade, depending on the season of the year and its formal characteristics. Regards to the data obtained from simulations, most of results were favorable to the use of green curtain sinthe solar control of the building, which saves energy for artificial heating or cooling, depending on the climatic region and the species concerned. Thus, the main conclusions of this research are related to the positive potential of using green curtains in architecture, serving both purposes of functionality and formal expression. The fact of one or more species of climbing plants be appropriate depend on each region, although, in general, the deciduous plants are more favorable in climates with hot and cold seasons, while perennial plants are more appropriate for the use in buildings with a predominance of high temperatures throughout the year.

Orientador: Prof. Dr. Jesus Franklin Andrade Romero / Dissertação (mestrado) - Universidade Federal do ABC. Programa de Pós-Graduação em Energia, 2015. / A avaliação da tecnologia é uma parte vital dos processos de decisão em projetos de eficiência energética em edificações, particularmente na seleção de novos processos de gestão sustentável. A sustentabilidade de uma edificação deve ser estimada com critérios que permitam comparações práticas mediante o uso de indicadores que avaliem as características de consumo, identifiquem suas práticas ambientais e permitam melhorar a eficiência energética na edificação. Para avaliar esses processos, uma abordagem baseada em uma matriz de sustentabilidade é introduzida considerando indicadores utilizados em modelos de certificação. Nesse sentido, é apresentada uma análise geral dos métodos de certificação de edificações considerando os indicadores atribuídos por cada um deles de forma a constituir-se uma matriz de avaliação de sustentabilidade, baseada nos indicadores do método que avalia edificações com características mais ajustadas ao contexto brasileiro, e aplicada em uma das edificações da Universidade Federal do ABC no campus Santo André. Objetivando subsidiar o procedimento proposto com modelos de eficiência energética de edificações, é utilizado um ambiente de simulação computacional baseado no do Programa Brasileiro de Etiquetagem. O estudo de caso mostra que a abordagem desenvolvida oferece uma forma flexível e prática para a avaliação da sustentabilidade em edificações públicas. / The evaluation of technology is a vital part of the decision-making processes in energy efficiency projects in buildings, particularly in the selection of new processes of sustainable management. The sustainability of a building must be estimated with criteria that allow practical comparisons through the use of indicators that evaluate the characteristics of consumption, identify their environmental practices and improving energy efficiency in building. To evaluate these processes, an approach based on an array of sustainability is introduced considering indicators used in certification models. In this sense, is presented a general analysis of the methods of certification of buildings considering the indicators assigned by each of them in order to become an evaluation buildings sustainability based on the indicators of the method that evaluates buildings with features more adjusted to the Brazilian context and applied in one of the buildings of Universidade Federal do ABC on campus Santo André. In order to subsidize the procedure proposed with models of energy efficiency of buildings, is used a computational simulation environment based on the Brazilian Labeling Program. Case study analysis the approach developed offers a flexible and practical manner for the sustainability evaluation of public buildings.

Orientador: Prof. Dr. Douglas Alves Cassiano / Dissertação (mestrado) - Universidade Federal do ABC. Programa de Pós-Graduação em Energia, 2015. / O acionamento de equipamentos rotativos na indústria petroquímica pode ser realizado a partir de motores elétricos ou turbinas a vapor. Os motores elétricos consomem energia elétrica e as turbinas a vapor consomem combustíveis, como Gás Natural e o Óleo Combustível. Os custos com estes insumos sofrem influência de vários fatores: políticas públicas, valor do dólar, valor do preço de mercado (PLD), valores de contrato e a própria eficiência de cada equipamento. Dessa forma, o objetivo geral deste trabalho é identificar oportunidades de eficiência energética na gestão do acionamento de equipamentos rotativos típicos de uma Indústria Petroquímica brasileira. Diante de tantas influências que variam em um curto espaço de tempo, uma ferramenta de apoio a gestão é a modelagem de equações lineares e integrais mistas (Mixed Integer Linear Programming ¿ MILP) para tomada de decisão com múltiplos critérios em relação ao consumo de energia nestes equipamentos. Comprovou-se que utilizando MILP é possível conquistar ganhos de eficiência energética. A escolha ótima do tipo de acionamento dos equipamentos rotativos e demais graus de liberdade apresentaram ganho anual médio de R$ 1.679.000/ano. A modelagem com MILP se mostrou eficaz, acurada e robusta. Foi confirmada a importância de uma modelagem e simulação de resposta rápida e a sua execução numa frequência maior possível, uma vez que os ganhos potenciais executando-se o modelo uma vez por dia foram 81% maiores do executando-se uma vez por mês. Esta metodologia apresenta um potencial de aplicação em outras plantas industriais, desde que possuam características semelhantes à estudada. / Rotating equipments in petrochemical industry are usually driven using steam turbines or electric motors. Electric motors consume electricity and steam turbines consume fuels such as natural gas and fuel oil. The costs of these energy inputs are influenced by: public policy, dollar rate, market prices, contracts values and equipments efficiency. Thus, the aim of this study is to identify energy efficiency opportunities at rotating equipment drive management of a Brazilian Petrochemical Industry. With so many influences that range in a short time, a management support tool is Mixed Integer Linear Programming ¿ MILP for decision making with multiple criteria. It was possible to prove that using MILP can achieve energy efficiency gains. The optimal rotating equipment drive choice and other degrees of freedom had an average annual gain of R$ 1,679,000/year. MILP proved effective, accurate and robust. It confirmed the importance of modeling and simulation with quickly response and its implementation in a higher possible rate, since the potential gains running the model once per day were 81% higher performing once a month. This methodology has a potential application in other industrial plants, since they have similar characteristics to the studied.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The classrooms are the more permanent environments at schools; therefore their thermal, visual and acoustic characteristics must be carefully considered. Visual comfort can be achieved only with daylighting; artificial lighting is necessary when the daylighting is insufficient. The artificial lighting is responsible for high energy consumption in buildings. According to Klüsener (2009), who analysed a building of UFSM in accordance with Brazilian energy efficiency standards (RTQ-C), the artificial lighting systems reached the level E (on a A-E scale). In general, simple actions could be improving the energy efficiency of the building lighting system. Considering that the university buildings have a similar performance, the adaptation of lighting systems is important for low-energy consumption. This study aims to define classrooms guidelines for visual comfort in accordance with illuminance levels available and their distribution on the work surface where tasks are performed, as well as the energy efficiency of the classrooms lighting systems. The classrooms were selected to represent the existing universe buildings. The classrooms were characterized with regard to dimensions, surface light reflections, opening systems, solar orientation, sun shading systems, external obstructions and artificial electrical lighting systems. The illuminance levels were measured in two classrooms simultaneously with Instrutherm luximeters, model LDR 225. The measurements were in accordance with the Brazilian standards (NBR 15215) and were carried out at six points on an orthogonal grid. A comparative analysis was made for the classrooms that were simultaneously measured. Additionally the partial RTQ-C lighting criteria were applied on the classrooms lighting systems and the theoretical external illuminance levels were calculated in order to generate the daylight factor (DF). The results pointed that the internal daylight distribution is affected by external obstructions that reduce the portion of visible sky and these are not considered in the windows design. For simultaneous daylighting and artificial lighting, the illuminance levels are excessive and poorly distributed; consequently they cause high energy consumption. The existence of unnecessary sun shading systems, for southern solar orientations and for windows with complete sky obstructions, contributes for the insufficient classrooms illuminance levels. The RTQ-C criteria analysis point levels E and C for the classrooms. In general, the DF do not correspond to expected values indicated by international recommendations. / As salas de aula, por serem ambientes de maior permanência dos alunos, devem possuir condições de conforto térmico, visual e acústico adequadas. O conforto visual pode ser obtido com a iluminação natural ou com auxilio da artificial quando a natural não é suficiente. Quando se utiliza a iluminação artificial, existe a preocupação com o consumo energético da edificação. Segundo estudos realizados por Klüsener (2009), que aplicou o Regulamento Técnico da Qualidade para Etiquetagem do Nível de Eficiência Energética de Edifícios (RTQ-C) em uma edificação do campus da UFSM em Camobi, o sistema de iluminação é de baixa eficiência energética, tendo atingido o nível E. No entanto, segundo o mesmo estudo, existe um potencial para a melhoria da eficiência energética a partir de ações simples. Partindo-se do pressuposto que as outras edificações da universidade possuem um desempenho semelhante, percebe-se a importância de adequar os seus sistemas de iluminação a fim de reduzir o consumo de energia. Esse trabalho tem como objetivo apontar diretrizes que visem o conforto visual no que diz respeito aos níveis de iluminância disponíveis e sua distribuição no ambiente, bem como à eficiência energética de sistemas de iluminação de salas de aula. Para isso, foram selecionadas salas de aula que fossem representativas do universo existente no campus. Após, foram feitos os levantamentos de suas características físicas (dimensões, cores das superfícies, tipos de aberturas, orientação solar, tipos de proteções solares, presença de obstruções externas, tipos e distribuição de luminárias e lâmpadas) e foram realizadas medições in loco com luxímetros digitais da marca Instrutherm, modelo LDR 225 e segundo recomendações da NBR 15215 (ABNT, 2005d). Também foi feita uma análise parcial segundo os Requisitos Técnicos da Qualidade para o Nível de Eficiência Energética de Edifícios Comerciais, de Serviços e Públicos (RTQ-C) e uma análise comparativa entre os níveis de iluminância medidos e os coeficientes de contribuição de iluminação natural (CIN) estimados. Com os resultados obtidos, verificou-se que a distribuição da iluminação natural é afetada por condições do entorno que causam obstruções do céu visível, não sendo consideradas no projeto das aberturas. Nas medições com iluminação natural mais artificial, os níveis são excessivos e mal distribuídos, causando consumo desnecessário de energia. As proteções solares presentes nas orientações a norte desconsideram as condições do entorno. A avaliação parcial através da aplicação dos requisitos específicos do RTQ-C para os sistemas de iluminação resultou em nível E para as salas do CE e em nível C para as outras. Os CIN calculados em grande parte do tempo não corresponderam aos valores teóricos esperados para salas de aula, conforme literatura.

Made available in DSpace on 2014-06-11T19:31:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-12-01Bitstream added on 2014-06-13T20:22:32Z : No. of bitstreams: 1 alves_af_dr_botfca.pdf: 3009487 bytes, checksum: 7d842f6597ccf4cbd7f7ebb8d5925852 (MD5) / A necessidade de oferecer alternativas para energização de propriedades rurais de pequeno porte com eficiência, confiabilidade e custo acessível, motivou a realização desta pesquisa, cujo enfoque principal foram os sistemas fotovoltaicos e a busca por um melhor desempenho destes sistemas a partir de estratégias de posicionamento dos painéis solares em direção ao Sol. Este trabalho apresenta o desenvolvimento experimental de um conjunto posicionador automático para módulos fotovoltaicos e a avaliação do funcionamento deste conjunto considerando-se o aumento na geração de energia elétrica em função da complexidade de implementação e do consumo de energia pelo próprio sistema de movimentação, além de seus custos de implantação. Foi projetado e implementado um dispositivo eletromecânico simplificado, capaz de sustentar e movimentar um módulo fotovoltaico ao longo do dia e ao longo do ano, sempre mantendo sua superfície direcionada em posição perpendicular aos raios solares incidentes. Utilizaram-se motores de passo, controlador lógico programável e componentes de baixo custo, que resultaram em um conjunto de manutenção simplificada,sem uso de sensores e com otimização dos movimentos, devido ao ajuste de inclinação do painel ser realizado somente uma vez ao dia. A avaliação do ganho na geração de energia elétrica baseou-se na coleta dos dados elétricos (tensão e corrente) e ambientais (insolação e temperatura) de dois sistemas fotovoltaicos com as mesmas características, instalados lado a lado, sujeitos às mesmas condições de insolação, temperatura e carga elétrica, sendo um fixo e outro móvel. A partir dos resultados obtidos concluiu-se pela viabilidade da proposta, não apenas pelo êxito no aumento da geração de energia, mas também pela boa relação custo/benefício, indicando que o sistema posicionador desenvolvido mostra-se vantajoso... / The need to offer alternatives of electricity supply to the small rural properties, providing them with efficiency, reliability and accessible cost, has motivated the development of this research, whose main approach was photovoltaic systems and the search for better performance of these systems with the solar panels positioning toward the sun. This work presents the experimental development of an automatic positioning system for photovoltaic modules and the evaluation of this system’s behavior taking in account the increase in generation of electric energy as a function of the complexity of implementation and the consumption of energy by the movement system itself, and its costs of implantation also. It was designed and built a simplified electromechanical device, which is able to support and to move a photovoltaic module along the day and along the year, always keeping its surface aimed to the sun rays. Stepper motors, programmable logic controller and low cost components were used, and these have resulted on a simplified maintenance set, with no sensors and optimization of movements, due the adjustment of panel’s inclination take place only once a day. The methodology adopted to evaluate the gain in the electricity generation was based on the acquisition of electrical data (voltage and current) and environmental data (insolation and temperature) from two photovoltaic systems whose have identical physical and electrical characteristics and were installed side by side, submitted to the same conditions of insolation, temperature and electric load. One of the solar panels was mounted on a fixed mechanical structure, and the other one on a mobile structure.The obtained results demonstrate the feasibility of the proposed mobile system, not only because of the real increase observed in electric energy generation, but also by the excellent cost effectiveness obtained... (Complete abstract click electronic access below)

Made available in DSpace on 2014-06-11T19:35:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-05-07Bitstream added on 2014-06-13T19:46:35Z : No. of bitstreams: 1 barretofilho_aa_dr_guara.pdf: 1308626 bytes, checksum: d6b803334313bd17282b33a8053a5352 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Duas das mais importantes tarefas do planejamento energético brasileiro correspondem a etapas periféricas do processo de gestão de recursos energéticos: A etapa que precede a elaboração das diretrizes e metas do planejamento propriamente dito e a que decorre deste processo, que corresponde ao acompanhamento da implantação das ações propostas e os inevitáveis ajustes de percurso. A regionalização do planejamento, no que concerne à incorporação e ampliação da exploração de recursos energéticos renováveis, implica na orientação para o reconhecimento das potencialidades energéticas específicas regionais e a sua integração à rede do sistema nacional – em diversos níveis e em distintas modalidades de interconexão. Pelo que implica no necessário estímulo à busca de ganhos de eficiência vocacionados conforme as potencialidades locais. Daí a necessária elaboração de ferramentas de análise, inventariamento e exploração de recursos energéticos combinados, em face da perspectiva de aumento da participação das energias renováveis na matriz energética brasileira. Do outro lado, a proposta elaborada reconhece que o acompanhamento da implantação de ações dos planos e programas energéticos significa coadunar (comparar e integrar) os avanços da participação regional com referências nacionais – e internacionais – propiciadoras de ganhos de eficiência global. A proposição de uma metodologia que avalia estas duas etapas, ao lado de ferramentas e procedimentos de comparação e integração de desempenhos de energéticos renováveis, é ao que se dedica este trabalho: recursos de planejamento que possam identificar e estimular ações estratégicas e estruturantes, regionalizadas, que alcancem os levantamentos ampliados das potencialidades locais e mesmo a participação de aspectos comportamentais, sociais... / Two of the most important tasks of the Brazilian energy planning stages correspond to the peripheral process of planning energy resources: The stage that precedes the preparation of guidelines and goals of the planning itself and the stage in which the process takes place, which is monitoring the implementation of the proposed actions and the inevitable adjustments of route. The regionalization of planning regarding the development and expansion of the exploitation of renewable energy resources, demands the guidance for the specific recognition of the potential energetic resources of a specific region and its integration into the regional network of the national system - at various levels and in different forms of interconnection. This implies the needed incentive in the search for efficiency oriented gains according to the local potential. Hence the necessary development of analysis tools, inventory and exploitation of combined energy resources, due to the perspective of increasing the share of renewable energies in the Brazilian energy matrix. On the other hand, this proposal recognizes that the monitoring of the implementation of action plans and energy programs means to combine (to compare and to integrate) the regional participation improvements with the national and international references favorable to global efficiency gains. The proposition of a methodology that evaluates these two steps, along with tools and procedures for comparison and integration of renewable energy performances, is the main subject to which this work is dedicated to: Planning resources that can identify and stimulate strategic actions and structures, regionalized, that reach the expanded surveys of potential sites and even the participation of behavioral, social and political aspects of the generation and consumption of energy... (Complete abstract click eletronic access below)

Cette thèse a pour objectif d'évaluer l'efficacité des dispositifs publics qui visent à inciter les agents à rénover leur logement afin d'en réduire la consommation énergétique. Il s'agit de combiner les deux dimensions clés de l'évaluation ex-post de l'intervention : la dimension récapitulative qui revient à déterminer l'efficacité des mesures mises en œuvre et la dimension formative qui vise à comprendre les résultats obtenus et à identifier les voies d'amélioration. Cela nécessite dans un premier temps de réaliser une analyse détaillée des facteurs qui sont à l'origine du faible niveau d'investissements, qualifié de déficit d'efficacité énergétique (« energy efficiency gap »). Ce déficit est dû à la présence de défaillances de marchés, aux conséquences de la rationalité limitée des ménages, ainsi qu'aux difficultés de coordination entre agents en particulier dans le cadre de la copropriété. Dans un deuxième temps il convient d'analyser le déficit d'efficacité énergétique en comparant les prescriptions qui peuvent être issues des calculs utilisés en économie publique concernant les investissements à réaliser, avec les données issues des études de terrain sur les investissements effectifs. Cette analyse permet de bien identifier les critères de décisions des ménages et ainsi de comprendre comment les barrières à l'efficacité énergétique se manifestent. L'identification des différentes barrières permet alors, dans un troisième temps, de voir si les dispositifs d'incitations aujourd'hui en application en France permettent de lever tous les obstacles aux investissements d'amélioration énergétique. Il apparaît que la multitude de dispositifs mis en œuvre ne peut suffire à réduire fortement le déficit d'efficacité énergétique. D'une part, certaines barrières ne sont pas levées car aucun outil approprié n'existe. D'autre part, certains facteurs de blocages, ne sont que partiellement traités car l'utilisation pratique des outils diffèrent de leur conception théorique. Finalement, l'analyse des programmes de réhabilitation thermique des logements qui ont été engagés sur le territoire grenoblois permet de déterminer l'efficacité des dispositifs additionnels c'est à dire d'évaluer dans quelle mesure ces interventions «renforcées» permettent de lever les barrières qui n'ont pu l'être avec les dispositifs nationaux. La mise en perspective de ces quatre analyses successives – des causes du déficit ; de sa manifestation ; des instruments nationaux ; des programmes mis en œuvre à l'échelle locale – aboutit à la conclusion d'un nécessaire renforcement des mesures non financières pour l'accompagnement des agents afin d'amorcer la dynamique d'investissement et ainsi créer les conditions de l'efficacité des instruments économiques plus généraux. / This PhD dissertation focuses on energy efficiency policies in housing. It aims at evaluating the effectiveness of public incentives designed to increase household's investment in energy efficiency of their dwelling. To reach this objective this research combines the two key dimensions of ex-post evaluation, i.e. summary and formative dimensions. The first one aims at knowing the effectiveness of public policies whereas the other one targets to understand what the public policies' consequences are and to identify ways for improvement. To reach this purpose, the research follows four steps. Firstly, it requires a detailed analysis to understand the origins of the energy efficiency gap. This gap can be explained by markets failures, consequences of bounded rationality and coordination problem between stakeholders, especially in multi-family dwellings. Secondly, the argument progresses by drawing a parallel between results from normative analysis and from observations of actual level of investments in thermal retrofit actions. It aims at identifying investment households' criteria and then at understanding how barriers to energy efficiency raise. Thirdly, thanks to the inventory of these various energy efficiency barriers it becomes possible to examine if the incentives currently implemented in France can remove them all. It appears that the national policy does not significantly reduce the energy efficiency gap. On the one hand, some barriers remain because no tool has been proposed to overcome them. On the other hand, some barriers are only partially eliminated because the practical use of tools differs from their theoretical design. Finally, using the analysis of retrofitting programs implemented on the Grenoble area this research assesses the effectiveness of additional incentives. The objective is to know to what extent these “reinforced” policies remove barriers still existing after national tools implementation. From these four successive analyses – causes, appearance of the energy efficiency gap, national tools, programs implemented at the local level – we conclude to a necessary strengthening of non-financial measures which support agents to initiate an investment dynamic and in the meanwhile to an increase of the reliability of economic tools, such as taxes or subventions

Les contraintes présentes dans les réseaux de capteurs impliquent l'introduction de techniques d'optimisation à différents niveaux de conception : du matériel au logiciel et dans la pile de communication. En effet, le déploiement des réseaux de capteurs, à faible consommation énergétique, exige une conception conjointe du matériel et du logiciel adaptée à l'application visée. Étant donné la nature évènementielle et multitâche des applications dans les réseaux de capteurs, nous pourrions penser à rajouter différentes unités de traitement qui coopèrent pour gérer les évènements et les tâches de manière optimale. Ainsi, la complexité des tâches accomplies par le processeur principal peut être réduite, ce qui contribue à atteindre l'efficacité énergétique. Dans cette thèse nous étudions un ensemble de protocoles qui facilitent l'implémentation des smart radios. L'idée principale des smart radios est l'introduction de l'intelligence dans la puce radio de manière à ce qu'elle soit capable de prendre des décisions ainsi que d'exécuter plusieurs tâches de manière autonome et sans l'intervention du processeur principal. Cette dernière sera responsable du bootstrap du réseau et, après qu'un état stable est atteint, le processeur peut rester inactif la plupart du temps, alors que la puce radio continue à fournir un ensemble de services. Le protocole proposé est appelé Wake on Idle et il fournit la maintenance de voisinage intégrée avec une méthode d'accès au canal. Ces services sont basés sur des transmissions analogiques qui sont codées dans le temps. De cette manière, dès que le réseau entre dans l'état stable (c.à.d. la topologie est formée et les noeuds sont associés et synchronisés), le traitement numérique de trames n'est pas nécessaire. Puisque Wake on Idle est basé sur des informations de bas niveau, il peut être facilement intégré dans la puce radio et fonctionner comme un coprocesseur qui fournit des services de haut niveau au processeur principal, comme la maintenance du voisinage et l'accès au canal. Grâce à une analyse théorique et une implémentation préliminaire, nous démontrons la faisabilité du protocole et nous montrons plusieurs caractéristiques intéressantes qui aident à atteindre l'efficacité énergétique et de bonnes performances. Ensuite, nous exploitons la signalisation analogique afin d'optimiser le duty-cycle des protocoles d'accès au canal existants. Nous proposons également un mécanisme appelé Sleep on Idle qui est basé sur l'échange de signaux analogiques ou busy tones. Sleep on Idle peut être intégré dans la radio et il peut décider quand le processeur doit être réveillé. Enfin, nous avons intégré le mécanisme de notification dans le standard IEEE802.15.4 et nous avons évalué ce mécanisme par des simulations et expérimentations. Les résultats montrent un gain important en termes de consommation en énergie et de réactivité du réseau. / The constraints of Wireless Sensor Networks scenarios require the introduction of optimization techniques at different design levels: from the hardware to the software and communication protocol stack. In fact, the design of energy efficient WSNs involves an appropriate hardware/software co-design oriented to the concerned application. Given the event driven and multitasking nature of WSNs applications, one could think of adding different processing units that cooperate to manage events and tasks in an optimal way. Then, the complexity of tasks performed by the main processing unit can be reduced and energy efficiency can be achieved. In this PhD thesis we study protocols that leverage the implementation of smart radios. The idea of smart radios is introducing intelligence into the radio chip; in this way, it will be able to take decisions and perform several tasks in an autonomous way and without any intervention of the main processing unit. The processing unit will be in charge of bootstrapping the network and, after a stable state is reached, it can remain inactive most of the time while the radio chip provides a given set of services. The proposed protocol is called Wake on Idle and it provides integrated neighborhood maintenance and low duty-cycle medium access control. These services are provided based on analog transmissions that are time encoded; then, as soon as the network enters the stable state (i.e. the topology is formed and nodes are associated and synchronized) digital processing of frames is not needed. Since it relies on low-level information, Wake on Idle can be easily implemented on hardware and integrated into the radio chip; then, it works as a coprocessor that provides high-level services (i.e. neighborhood maintenance and medium access) to the main processing unit. Through theoretical analysis and a preliminary implementation we demonstrate the feasibility of the protocol and we show several interesting characteristics that help achieving energy efficiency and good performance. Then, we further exploit analog signaling to optimize duty cycle of existing medium access control protocols. We propose a mechanism called Sleep on Idle and it is based on the exchange of analog busy tones. Sleep on Idle can also be integrated into the smart radio to take decisions about whether the main processing unit has to be woken up. We apply the decision mechanism to the slotted ieee802.15.4 standard and validate it through simulations and experimentations. The results show an important gain in terms of energy consumption and network reactivity.

L'une des stratégies utilisée pour augmenter l'efficacité spectrale (ES) des réseaux cellulaires est de réutiliser la bande de fréquences sur des zones relativement petites. Le problème majeur dans ce cas est un plus grand niveau d'interférence, diminuant l'efficacité énergétique (EE). En plus d'une plus grande largeur de bande, la densification des réseaux (cellules de petite taille ou multi-utilisateur à entrées multiples et sortie unique, MU-EMSO), peut augmenter l'efficacité spectrale par unité de surface (ESuS). La consommation totale d'énergie des réseaux sans fil augmente en raison de la grande quantité de puissance de circuit consommée par les structures de réseau denses, réduisant l'EE. Dans cette thèse, la région EE-SE est caractérisé dans un réseau cellulaire hexagonal en considérant plusieurs facteurs de réutilisation de fréquences (FRF), ainsi que l'effet de masquage. La région EE-ESuS est étudiée avec des processus de Poisson ponctuels (PPP) pour modéliser un réseau MU-EMSO avec un précodeur à rapport signal sur fuite plus bruit (RSFB). Différentes densités de station de base (SB) et nombre d'antennes aux SB avec une consommation d'énergie statique sont considérées.Nous caractérisons d'abord la région EE-SE dans le réseau cellulaire hexagonal pour différentes FRF, avec et sans masquage. Avec le masquage en plus de la perte de propagation, la mesure de coupure ε-EE-ES est proposée pour évaluer les performances. Les courbes EE-ES présentent une grande partie linéaire, due à la consommation de puissance statique, suivie d'une forte diminution de l'EE, puisque le réseau est homogène et limité par les interférences. Les résultats montrent qu'un FRF de 1 pour les régions proches de la SB et des FRF plus élevés dans la région plus proche du bord de la cellule améliorent le point optimal du EE-ES. De plus, un meilleur compromis EE-ES peut être obtenu avec une valeur plus élevée de coupure. En outre, un FRF de 1 est le meilleur choix pour une valeur élevée de coupure en raison d'une réduction du rapport signal sur interférence plus bruit (RSIB).Les précodeurs sont utilisés en liaison descendante des réseaux cellulaires MU-EMSO à accès multiple par division spatiale (AMDS) pour améliorer le RSIB. La géométrie stochastique a été utilisée intensivement pour analyser de tels systèmes complexes. Nous obtenons une expression analytique de l'ESuS en régime asymptotique, c.-à-d. nombre d'antennes et d'utilisateurs infinis, en utilisant des résultats de matrices aléatoires et de géométrie stochastique. Les SBs et les utilisateurs sont modélisés par deux PPP indépendants et le précodage RSFB est utilisé. L'EE est dérivée d'un modèle de consommation de puissance linéaire. Les simulations de Monte Carlo montrent que les expressions analytiques sont précises même pour un nombre faible d'antennes et d'utilisateurs. De plus, les courbes d'EE-ESuS ont une grande partie linéaire avant une forte décroissante de l'EE, comme pour les réseaux hexagonaux. Les résultats montrent également que le précodeur RSFB offre de meilleurs performances que le précodeur forçage à zéro (FZ), qui est typiquement utilisé dans la literature. Les résultats numériques pour le précodeur RSFB montrent que déployer plus de SBs ou d'antennes aux BSs augmente l'ESuS, mais que le gain dépend du rapport des densités SB-utilisateurs et du nombre d'antennes lorsque la densité de l'utilisateur est fixe. L'EE augmente seulement lorsque l'augmentation de l'ESuS est plus importante que l'augmentation de la consommation d'énergie par unité de surface. D'autre part, lorsque la densité d'utilisateur augmente, l'ESuS dans la région limitée par les interférences peut être améliorée en déployant davantage de SB sans sacrifier l'EE et le débit ergodique des utilisateurs. / One of the used strategies to increase the spectral efficiency (SE) of cellular network is to reuse the frequency bandwidth over relatively small areas. The major issue in this case is higher interference, decreasing the energy efficiency (EE). In addition to the higher bandwidth, densification of the networks (e.g. small cells or multi-user multiple input single output, MU-MISO) potentially increases the area spectral efficiency (ASE). The total energy consumption of the wireless networks increases due to the large amount of circuit power consumed by the dense network structures, leading to the decrease of EE. In this thesis, the EE-SE achievable region is characterized in a hexagonal cellular network considering several frequency reuse factors (FRF), as well as shadowing. The EE-ASE region is also studied using Poisson point processes (PPP) to model the MU-MISO network with signal-to-leakage-and-noise ratio (SLNR) precoder. Different base station (BS) densities and different number of BS antennas with static power consumption are considered.The EE-SE region in a hexagonal cellular network for different FRF, both with and without shadowing is first characterized. When shadowing is considered in addition to the path loss, the ε-SE-EE tradeoff is proposed as an outage measure for performance evaluation. The EE-SE curves have a large linear part, due to the static power consumption, followed by a sharp decreasing EE, since the network is homogeneous and interference-limited. The results show that FRF of 1 for regions close to BS and higher FRF for regions closer to the cell edge improve the EE-SE optimal point. Moreover, better EE-SE tradeoff can be achieved with higher outage values. Besides, FRF of 1 is the best choice for very high outage value due to the significant signal-to-interference-plus-noise ratio (SINR) decrease.In downlink, precoders are used in space division multiple access (SDMA) MU-MISO cellular networks to improve the SINR. Stochastic geometry has been intensively used to analyse such a complex system. A closed-form expression for ASE in asymptotic regime, i.e. number of antennas and number of users grow to infinity, has been derived using random matrix theory and stochastic geometry. BSs and users are modeled by two independent PPP and SLNR precoder is used at BS. EE is then derived from a linear power consumption model. Monte Carlo simulations show that the analytical expressions are tight even for moderate number of antennas and users. Moreover, the EE-ASE curves have a large linear part before a sharply decreasing EE, as observed for hexagonal network. The results also show that SLNR outperforms the zero-foring (ZF) precoder, which is typically used in literature. Numerical results for SLNR show that deploying more BS or a large number of BS antennas increase ASE, but the gain depends on the BS-user density ratio and on the number of antennas when user density is fixed. EE increases only when the increase in ASE dominates the increase of the power consumption per unit area. On the other hand, when the user density increases, ASE in interference-limited region can be improved by deploying more BS without sacrificing EE and the ergodic rate of the users.

The International Energy Agency has stated that it is more sustainable to improve the energy efficiency of already existing buildings than increasing the national energy production to provide inefficient buildings with even more energy, which would result in that an increased amount of resources required to power the existing energy inefficient building stock. Taken into consideration that buildings in Sweden consume about 40% of Sweden’s final energy consumption and count for about 36% of the total greenhouse gas emissions it becomes evident that in order to decrease Sweden’s carbon foot print, it is important to understand real estate investors decision-making process. The aspiration is to provide stakeholders both on a micro and macro level with a better understanding of the real estate investors decision making process. This will enable companies (micro level) in the field to better customize their value propositions and there by enable companies to contribute to decreasing the primary energy consumption of buildings in Sweden. The macro level, referring to governmental institutions, will be provided with a better understanding of what kind of measures can be taken, to increase investments into buildings energy efficiency. It could be found from the literature reviewed for the study that there is a gap in research what comes to the Swedish market. Majority of the existing literature covers bigger markets e.g. the USA and UK but very little or if at all the Swedish market. During the literature study an existing framework on decision drivers for real estate investors was developed. The study uses mixed method consisting of qualitative and quantitative methods to answer the research questions. The study showed that the most prominent drivers on the Swedish market were the customers strategic decisions, environmental and energy certificates, reporting protocols, investment horizon, rental agreements, internal investment policies decreased property costs and building specific characteristics. It was found that the Swedish real estate investors experience very little pressure from the government to increase the energy efficiency of their buildings. It was also found that governmental subsidies are more considered a gamble than an encouragement to invest in energy efficiency due to long processing times and heavy bureaucracy.