"Opportunistic routing (OR) takes advantages of the spatial diversity and broadcast nature of wireless networks to combat the time-varying links by involving multiple neighboring nodes (forwarding candidates) for each packet relay. This dissertation studies the properties, energy efficiency, capacity, throughput, protocol design and security issues about OR in multihop wireless networks. Firstly, we study geographic opportunistic routing (GOR), a variant of OR which makes use of nodes' location information. We identify and prove three important properties of GOR. The first one is on prioritizing the forwarding candidates according to their geographic advancements to the destination. The second one is on choosing the forwarding candidates based on their advancements and link qualities in order to maximize the expected packet advancement (EPA) with different number of forwarding candidates. The third one is on the concavity of the maximum EPA in respect to the number of forwarding candidates. We further propose a local metric, EPA per unit energy consumption, to tradeoff the routing performance and energy efficiency for GOR. Leveraging the proved properties of GOR, we propose two efficient algorithms to select and prioritize forwarding candidates to maximize the local metric. Secondly, capacity is a fundamental issue in multihop wireless networks. We propose a framework to compute the end-to-end throughput bound or capacity of OR in single/multirate systems given OR strategies (candidate selection and prioritization). Taking into account wireless interference and unique properties of OR, we propose a new method of constructing transmission conflict graphs, and we introduce the concept of concurrent transmission sets to allow the proper formulation of the maximum end-to-end throughput problem as a maximum-flow linear programming problem subject to the transmission conflict constraints. We also propose two OR metrics: expected medium time (EMT) and expected advancement rate (EAR), and the corresponding distributed and local rate and candidate set selection schemes, the Least Medium Time OR (LMTOR) and the Multirate Geographic OR (MGOR). We further extend our framework to compute the capacity of OR in multi-radio multi-channel systems with dynamic OR strategies. We study the necessary and sufficient conditions for the schedulability of a traffic demand vector associated with a transmitter to its forwarding candidates in a concurrent transmission set. We further propose an LP approach and a heuristic algorithm to obtain an opportunistic forwarding strategy scheduling that satisfies a traffic demand vector. Our methodology can be used to calculate the end-to-end throughput bound of OR in multi-radio/channel/rate multihop wireless networks, as well as to study the OR behaviors (such as candidate selection and prioritization) under different network configurations. Thirdly, protocol design of OR in a contention-based medium access environment is an important and challenging issue. In order to avoid duplication, we should ensure only the "best" receiver of each packet to forward it in an efficient way. We investigate the existing candidate coordination schemes and propose a "fast slotted acknowledgment" (FSA) to further improve the performance of OR by using a single ACK to coordinate the forwarding candidates with the help of the channel sensing technique. Furthermore, we study the throughput of GOR in multi-rate and single-rate systems. We introduce a framework to analyze the one-hop throughput of GOR, and provide a deeper insight on the trade-off between the benefit (packet advancement, bandwidth, and transmission reliability) and cost (medium time delay) associated with the node collaboration. We propose a local metric named expected one-hop throughput (EOT) to balance the benefit and cost. Finally, packet reception ratio (PRR) has been widely used as an indicator of the link quality in multihop wireless networks. Many routing protocols including OR in wireless networks depend on the PRR information to make routing decision. Providing accurate link quality measurement (LQM) is essential to ensure the right operation of these routing protocols. However, the existing LQM mechanisms are subject to malicious attacks, thus can not guarantee to provide correct link quality information. We analyze the security vulnerabilities in the existing link quality measurement (LQM) mechanisms and propose an efficient broadcast-based secure LQM (SLQM) mechanism, which prevents the malicious attackers from reporting a higher PRR than the actual one. We analyze the security strength and the cost of the proposed mechanism. "

There is a large demand for applications of high data rates in wireless networks. These networks are becoming more complex and challenging to manage due to the heterogeneity of users and applications specifically in sophisticated networks such as the upcoming 5G. Energy efficiency in the future 5G network is one of the essential problems that needs consideration due to the interference and heterogeneity of the network topology. Smart resource allocation, environmental adaptivity, user-awareness and energy efficiency are essential features in the future networks. It is important to support these features at different networks topologies with various applications. Cognitive radio has been found to be the paradigm that is able to satisfy the above requirements. It is a very interdisciplinary topic that incorporates flexible system architectures, machine learning, context awareness and cooperative networking. Mitola’s vision about cognitive radio intended to build context-sensitive smart radios that are able to adapt to the wireless environment conditions while maintaining quality of service support for different applications. Artificial intelligence techniques including heuristics algorithms and machine learning are the shining tools that are employed to serve the new vision of cognitive radio. In addition, these techniques show a potential to be utilized in an efficient resource allocation for the upcoming 5G networks’ structures such as heterogeneous multi-tier 5G networks and heterogeneous cloud radio access networks due to their capability to allocate resources according to real-time data analytics. In this thesis, we study cognitive radio from a system point of view focusing closely on architectures, artificial intelligence techniques that can enable intelligent radio resource allocation and efficient radio parameters reconfiguration. We propose a modular cognitive resource management architecture, which facilitates a development of flexible control for resources management in diverse wireless networks. The core operation of the proposed architecture is decision-making for resource allocation and system’s parameters adaptation. Thus, we develop the decision-making mechanism using different artificial intelligence techniques, evaluate the performance achieved and determine the tradeoff of using one technique over the others. The techniques include decision-trees, genetic algorithm, hybrid engine based on decision-trees and case based reasoning, and supervised engine with machine learning contribution to determine the ultimate technique that suits the current environment conditions. All the proposed techniques are evaluated using testbed implementation in different topologies and scenarios. LTE networks have been considered as a potential environment for demonstration of our proposed cognitive based resource allocation techniques as they lack of radio resource management. In addition, we explore the use of enhanced online learning to perform efficient resource allocation in the upcoming 5G networks to maximize energy efficiency and data rate. The considered 5G structures are heterogeneous multi-tier networks with device to device communication and heterogeneous cloud radio access networks. We propose power and resource blocks allocation schemes to maximize energy efficiency and data rate in heterogeneous 5G networks. Moreover, traffic offloading from large cells to small cells in 5G heterogeneous networks is investigated and an online learning based traffic offloading strategy is developed to enhance energy efficiency. Energy efficiency problem in heterogeneous cloud radio access networks is tackled using online learning in centralized and distributed fashions. The proposed online learning comprises improvement features that reduce the algorithms complexities and enhance the performance achieved.

In this thesis, I analyze the impacts of the design and implementation of different environmental policy tools from a theoretical and empirical perspective: certificates providing information on the energy performance of buildings (chapter 1); urban road pricing schemes such as congestion charges (chapter 2); quantity-based policy tools to support production with non-polluting technologies (chapter 3).In chapter 1, co-authored with Luisa Dressler, we study how energy performance certificates (EPCs) impact the residential rental market. These certificates can help solve information asymmetries between landlords and tenants about the thermal quality of dwellings for rent, which, in turn, is expected to facilitate investment aimed at improving dwellings' energy performance. However, disclosure of EPCs is often incomplete, which hampers their effectiveness in relieving such information asymmetries. Moreover, even when a certificate is available, landlords do not always disclose it. This contradicts the so-called information unraveling result, according to which all landlords should disclose quality information unless it is costly to do so: in such a setting, information eventually unravels. Using a cross-sectional dataset of residential rental advertisements from the Belgian region of Brussels, we empirically evaluate incentives to disclose energy performance ratings. We find that two fundamental assumptions underlying the unraveling result are not confirmed in our setting: firstly, tenants value energy performance of rental property only when dwellings are of very high quality; secondly, tenants do not appear to rationally adjust their expectations when faced with dwellings that withhold their energy performance rating. Finally, we formulate specific policy advice for reforming EPC mechanisms to increase disclosure rates.In chapter 2, I study how urban congestion pricing impacts the use of sustainable mobility options such as bike sharing, presenting evidence from the city of Milan, Italy.As concern for air pollution grows in cities across the world, policies such as urban road pricing are rolled out to induce urban residents to opt for greener transport options. While several papers have analyzed the impact of urban road pricing on air pollution and on car use, this is the first analysis of its impact on sustainable travel behaviors, such as the use of bike sharing.I extend a stylized theoretical model of travel behavior to formalize the drivers of bike-sharing demand. Then, I exploit a panel dataset covering all bike-sharing trips carried out over an 8-year period in the city of Milan to estimate the impact of congestion pricing on bike-sharing use. The empirical strategy I employ in this study is based on the sudden suspension and reintroduction of congestion pricing, which generate a quasi-experimental setting. Adopting an event study approach, I find that suspending the congestion charge reduces daily bike-sharing traffic by about 5% in the short run. I show that, in Milan, congestion pricing mainly impacts bike-sharing use through the reduction of road traffic congestion, which makes cycling safer and more pleasant. The direct effect of the increased relative cost of car use is secondary in individual decisions to use bike-sharing. The role of these effects is likely to be context-specific, as they may be affected by the baseline level of urban congestion, the broader policy mix affecting the cost of driving and the specific design of the congestion pricing scheme.In chapter 3, co-authored with Renaud Foucart, we study the impact of different quantity-based tools that governments can use to support the production of homogeneous goods through clean rather than polluting inputs in a setting where production costs are uncertain.In recent years, many sectors have been disrupted by clean innovation, as clean inputs have emerged as close substitutes of polluting ones: for example, in the power sector renewable energy sources are increasingly used for electricity generation instead of fossil fuels. Whenever the negative externalities caused by polluting incumbent technologies are not internalized in production costs, emerging clean technologies are left at a disadvantage. For this reason, governments may want to design policy support schemes for emerging clean technologies.We develop a theoretical framework in which well-established polluting technologies entail known production and pollution costs, while using emerging green technologies requires higher, steeper and uncertain production costs. In this context, a government chooses between a range of quantity-based instruments to support the deployment of clean technologies based on cost estimates, as costs of production with green inputs are uncertain.We show that a cap on production with polluting inputs is the least distortionary among quantity instruments; next is a mandatory share of production with green inputs out of total production. Setting a policy objective in terms of a precise level of green inputs for production is the least efficient policy approach. This ranking results from the so-called “technology effect”, which determines the extent to which the market corrects cost estimation errors after real costs are observed. / Doctorat en Sciences économiques et de gestion / info:eu-repo/semantics/nonPublished

Submitted by JOSIANE SANTOS DE OLIVEIRA (josianeso) on 2017-05-30T12:21:44Z No. of bitstreams: 1 Talita de Albuquerque Barreto_.pdf: 3641892 bytes, checksum: f2e5a2fbe9ce56b1af55edb294e16c77 (MD5) / Made available in DSpace on 2017-05-30T12:21:44Z (GMT). No. of bitstreams: 1 Talita de Albuquerque Barreto_.pdf: 3641892 bytes, checksum: f2e5a2fbe9ce56b1af55edb294e16c77 (MD5) Previous issue date: 2016-12-22 / Nenhuma / Uma ação importante para a sustentabilidade é a redução do consumo de energia, buscando atingir a eficiência energética dos edifícios. Os aeroportos têm incorporado progressivamente operações comerciais e de lazer que os aproximam de centros comerciais, com um aumento no consumo de energia para iluminação artificial e condicionamento do ambiente considerando a operação 24/7. No entanto, muitas vezes não são desenvolvidos planos de eficiência energética. O Aeroporto Internacional Salgado Filho, localizado em Porto Alegre, sul do Brasil, tem cerca de 100 mil operações de aeronaves, entre pousos e decolagens, por ano, o que representa 4% do movimento nacional. Nesse contexto, este estudo tem como objetivo avaliar a eficiência energética do aeroporto mencionado. Este trabalho utiliza como parâmetro a certificação brasileira PROCEL Edifica. Foram coletados dados de consumo de energia de dois anos de operação do aeroporto. A eficiência energética foi avaliada através de condições técnicas de edifícios e sistemas operacionais, seguida por análise e classificação pelo método PROCEL Edifica. Os resultados apontaram para classificação geral da edificação como C no terminal 1 e classificação A no terminal 2. Os sistemas de iluminação e condicionamento de ar tiveram classificação abaixo do nível A e a partir da identificação de itens não atendidos do método, foram propostas ações para a redução do consumo de energia no aeroporto com a análise da viabilidade econômica dessas propostas. / An important action for sustainability is the reduction of energy consumption, seeking to achieve the energy efficiency of buildings. Airports have progressively incorporated commercial and leisure operations that bring them closer to shopping centers, with an increase in energy consumption for artificial lighting and environmental conditioning considering the operation 24/7. However, energy efficiency plans are often not developed. Salgado Filho International Airport, located in Porto Alegre, southern Brazil, has about 100,000 aircraft operations, between landings and takeoffs, per year, which represents 4% of the national movement. In this context, this study aims to evaluate the energy efficiency of the mentioned airport. This work uses as a parameter the Brazilian certification PROCEL Edifica. Energy consumption data from two years of airport operation were collected. Energy efficiency was evaluated through technical conditions of buildings and operating systems, followed by analysis and classification by PROCEL Constructs method. The results pointed to the overall classification of the building as C at terminal 1 and classification A at terminal 2. Lighting and air conditioning systems were rated below level A and from the identification of unmet items of the method, actions were proposed to reduce energy consumption at the airport with the analysis of the economic viability of these proposals.

Submitted by Maicon Juliano Schmidt (maicons) on 2015-05-21T13:43:20Z No. of bitstreams: 1 Dário da Rosa Cruz.pdf: 2357249 bytes, checksum: cc31613a7629955b25090b2c81265ab5 (MD5) / Made available in DSpace on 2015-05-21T13:43:20Z (GMT). No. of bitstreams: 1 Dário da Rosa Cruz.pdf: 2357249 bytes, checksum: cc31613a7629955b25090b2c81265ab5 (MD5) Previous issue date: 2015-01-09 / IFSUL - Instituto Federal de Educação, Ciência e Tecnologia Sul-rio-grandense / No presente trabalho foi analisado um sistema de cogeração de uma empresa de alimentos que utiliza, em seu processo produtivo, diversas utilidades. Estes processos geram resíduos industriais, como sólidos, líquidos e também resíduos térmicos. Atualmente muito tem se falado sobre eficiência energética no setor de utilidades, a qual impacta diretamente nos custos operacionais de produção. O objetivo deste trabalho é identificar potenciais térmicos disponíveis para a simulação de um sistema de trigeração, que utiliza sistema de refrigeração por absorção amônia/água como uma alternativa na redução dos custos operacionais mediante a produção de água gelada e de refrigeração para túneis de congelamento. Na empresa em análise, a demanda por energia elétrica para sistemas de refrigeração por compressão representa atualmente 60% da energia elétrica total da fábrica. Deste modo, sistemas de refrigeração por absorção mostram-se interessantes para diversas aplicações, pois são movidos por energia térmica ao invés de energia elétrica. Neste estudo são analisadas as influências da temperatura de condensação, temperatura de evaporação, temperatura do gerador e concentrações de amônia sobre o COP do sistema de refrigeração por absorção amônia/água. Para a análise destas influências, foi realizado o modelamento matemático e desenvolvido um programa no EES (Engineering Equation Solver) e os resultados da simulação foram comparados com os resultados encontrados nas simulações do Handbook fundamentals da ASHRAE (2009). A partir daí são simulados três diferentes casos para os sistemas de absorção em estudo, onde os dados coletados na empresa, referentes aos potenciais de recuperação de calor, e os parâmetros da ASHRAE para sistemas de refrigeração por absorção NH3/H2O, são simulados e analisados mediante o programa IPSEpro®. Uma análise econômica é realizada, onde se pode concluir quanto à melhor configuração do sistema de trigeração sugerido. O percentual de economia, referente à energia elétrica consumida pelos compressores de refrigeração adotados foi de 8,7%, o qual proporcionará uma economia líquida mensal de R$ 135.391,41. O custo de energia elétrica considerado foi de R$ 0,1968/kWh e a TMA (taxa mínima de atratividade) considerada no projeto foi de 15,7%. A melhor situação apresentada foi a do caso 3, onde o valor do capital investido foi de R$ 5.368.700,00 referente à aquisição dos equipamentos e instalação e a TIR (taxa interna de retorno) ficou em 15,7%, o VPL (valor presente líquido) para 10 anos ficou em R$ 2.443.000,00 e o tempo de retorno payback se dará em 6,07 anos ou 73 meses. / In this present study, a cogeneration system is analyzed in a food company that uses several utilities in its productive process. These processes generate industrial residues, such as solids, liquids and also thermal residues. Currently, much has been said about energy efficiency in the utilities department to which directly impact the operational costs of production. The goal of this study is to identify thermal and energy potentials available for the simulation of a trigeneration system that uses absorption ammonia/water cooling system as an alternative to reduce operational costs through the production of cold water and the cooling of freezing tunnels. In the analyzed company, the demand for electric energy for the cooling systems by compression, represents lately 60% of all the electric energy of the factory. This way, cooling systems by absorption become interesting for many different applications, since they are activated by thermal energy instead of electric energy. In this study the influences of the condensation temperature, evaporation temperature, generator temperature and ammonia concentration by COP of absorption ammonia/water cooling systems are analyzed. For the fulfillment of these analysis, the mathematical modeling is carried out and an EES program is developed and compared through simulations performed in Handbook fundamentals by ASHRAE (2009). Therefore, three cases different are simulated for the absorption systems in study, where the data presented for the company potential recovery of heat a boiler and the ASHRAE guidelines for an ammonia/water absorption refrigeration systems, are simulated and analyzed through the IPSEpro software. An economical analysis is performed where it is possible to conclude the best configuration of the trigeneration system suggested. The percentage of economy concerned to the electric energy consumed by the adopted cooling compressors was 8.7%. It will proportionate a mouthy economy of around R$ 135,391.41. The costs of electric energy considered was R$ 0.1968/kWh and the TMA (minimal tax of attractiveness) considered in the project was 15.7% the best situation presented was the case 3, where the value of invested capital was R$ 5,368,700.00 concerned to the acquisition and installation of equipments. The TIR (internal rate of return) was in 15.7%, the VPL (net present value) for ten years was R$ 2,443,000.00 and the payback will occur in 6.07 years or 73 months.

Submitted by Silvana Teresinha Dornelles Studzinski (sstudzinski) on 2016-02-29T14:03:08Z No. of bitstreams: 1 Luciano Ghilardi Breitenbach_.pdf: 1516661 bytes, checksum: 05907a451007241e834fa21e460bdc4b (MD5) / Made available in DSpace on 2016-02-29T14:03:08Z (GMT). No. of bitstreams: 1 Luciano Ghilardi Breitenbach_.pdf: 1516661 bytes, checksum: 05907a451007241e834fa21e460bdc4b (MD5) Previous issue date: 2015-04-30 / Nenhuma / Simulação de uma residência unifamiliar de interesse social pelos métodos prescritivo e de simulação encontrados no RTQ-R (Regulamento Técnico da Qualidade para o Nível de Eficiência Energética de Edificações Residenciais) que faz parte do selo de eficiência energética do programa Procel Edifica criado pelo Ministério de Minas e Energia em parceria com o Governo Federal. Este estudo compara e avalia os métodos utilizados para qualificar energeticamente as edificações residenciais no Brasil. Com base nos resultados obtidos nas simulações propõe possíveis meios de ampliar o conforto ambiental e reduzir o consumo energético desse tipo de edificação. A avaliação é feita em uma edificação típica e com padrões mínimos exigidos pelo programa MCMV (Minha Casa, Minha Vida), situada na cidade de Porto Alegre no estado do Rio Grande do Sul, Brasil. O estudo é comparativo e adota diferentes critérios construtivos, dentre eles: a ampliação das aberturas para comparar a influência da ventilação e iluminação; alteração da absortividade externa da residência; sombreamento das aberturas que resultará em diferentes absorções de calor e a influência da orientação solar da edificação. Observou-se que, pelos critérios de avaliação encontrados no RTQ-R, para esta zona bioclimática do Brasil, há uma maior preocupação com as temperaturas quentes e, para estas, as medidas tomadas com intuito de ampliar o conforto se mostraram benéficas. A alteração da absortividade do revestimento externo da residência resultou em maior eficiência entre as demais medidas adotadas. Quando se fazem avaliações com as temperaturas frias e quentes, simultaneamente, e com o mesmo grau de importância, praticamente, temos uma compensação nos resultados, o que nos leva a entender por que o RTQ-R prioriza as temperaturas quentes. Ao serem avaliados os dois extremos de temperaturas focando o conforto ambiental, percebe-se que, pelos resultados encontrados, é mais lógico tratarmos com medidas naturais o extremo de temperaturas mais prejudicial ao conforto, para que, no outro extremo, possa ser utilizado algum sistema artificial de tratamento térmico, mas com menor impacto econômico. Um sistema de tratamento térmico poderia ser o uso do potencial geotérmico. Outro fator analisado é que o RTQ-R poderia ser mais criterioso e, também, demonstrou ser confuso. Neste trabalho propõe-se uma avaliação criteriosa em relação ao conforto ambiental para atender às necessidades dos usuários. / Simulation of a single-family residence social interest in prescriptive and simulation methods found in the RTQ-R (Quality Technical Regulation for Energy Efficiency Level Residential Buildings) part of the energy efficiency seal Procel Edifica program created by the Ministry of Mines and Energy in partnership with the Federal Government. This study compares and evaluates the methods used to qualify the energy residential buildings in Brazil. Based on the results obtained in the simulations proposes possible means of increasing the environmental comfort and reduce energy consumption of this type of building. The assessment is made in a typical building and minimum standards required by the MCMV (Minha Casa, Minha Vida), in the city of Porto Alegre in Rio Grande do Sul, Brazil. The study is comparative and adopts different construction criteria, including: the expansion of openings to compare the influence of ventilation and lighting; changing the external absorptivity of residence; shading of the openings will result in different absorption of heat and the influence of solar orientation of the building. It was observed that the evaluation criteria found in the RTQ-R, for this bioclimatic zone of Brazil, there is a greater concern with the warm temperatures and, for these, the measures taken in order to enlarge the comfort proved beneficial. Changing the absorptivity the outer covering of the residence resulted in greater efficiency among the other measures adopted. When making evaluations with the cold and warm temperatures simultaneously and with the same degree of importance, practically, we have a compensation in the results, which leads us to understand why the RTQ-R gives priority to hot temperatures. When evaluated the two extremes of temperatures focusing on the environmental comfort, it is clear that the results found, it is more logical to treat natural extreme measures more harmful to the comfort temperature, so that at the other end, can be used a system artificial heat treatment but with less economic impact. A thermal treatment system could be the use of geothermal potential. Another factor considered is that RTQ-R could be more selective and also proved to be confused. In this paper we propose a careful assessment in relation to environmental comfort to meet the needs of users.

This dissertation examines why planning is perceived as a barrier to the thermal improvement of conservation properties, and considers ways in which this might be addressed. The focus on thermal improvement is derived from a survey of UK scenario literature for energy management up to 2050. A further examination of the literature finds that conservation properties are particularly in need of thermal improvement; and barriers to thermal improvement are identified. A gap in the academic knowledge is found that identifies planning as a perceived barrier, but that there is no investigation of this widely held perception. The research question is therefore developed as, 'Why is English planning perceived as a barrier to the thermal improvement of conservation properties and how can it be addressed?' The dissertation methodology uses a pragmatic mixed-methods approach and research design. The first phase of the research examines 'Why planning is perceived as a barrier', by using surveys and interviews to gather evidence of the experiences and opinions of the multiple users of planning for conservation projects. Through this work, a lack of consistency and reliability in English planning is identified. The data suggests this may be due to the discretionary and fragmented nature of the English planning system which requires local authorities to interpret national policies and develop local plans and guidance. This results in local decision-making, which may not be consistent. Additionally, the research finds a perceived lack of strong national policy and guidance. This perceived lack of consistency and reliability in the application of planning is selected as the basis for validation phase of the dissertation research findings. The validation research seeks to test the perception of a lack of consistency and reliability through a Comparative Information Quality assessment adapted and developed from the discipline of Information Management. Online planning guidance for conservation projects provided by 13 London Councils is compared. The method confirms and highlights areas of inconsistency across the Councils' planning guidance. By identifying a number of areas of inconsistency, and by providing a tool that could help to ensure that policy is delivered consistently at the local level, this component of the research addresses the second part of the research question, 'How can the planning barrier be addressed?'. In conclusion, the dissertation suggests that planning is perceived as a barrier due to a lack of consistency and reliability in the planning process. Inconsistencies are identified and a recommendation is made for how these might be reduced.

Até 2020 espera-se que as redes celulares aumentam em dez vezes a área de cobertura, suporte cem vezes mais equipamentos de usuários e eleve a capacidade da taxa de dados em mil vezes, comparada as redes celulares atuais. A densa implantação de pequenas células é considerada uma solução promissora para alcançar essas melhorias, uma vez que aproximar as antenas dos usuários proporciona maiores taxas de dados, devido à qualidade do sinal em curtas distâncias. No entanto, operar um grande número de antenas pode aumentar significativamente o consumo de energia da infraestrutura de rede. Além disso, a grande inserção de novos rádios pode ocasionar maior interferência espectral entre as células. Nesse cenário, a gestão dos recursos de rádio é essencial devido ao impacto na qualidade do serviço prestado aos usuários. Por exemplo, baixas potências de transmissão podem deixar usuários sem conexão, enquanto altas potências elevam a possibilidade de ocorrência de interferência. Além disso, a reutilização não planejada dos recursos de rádio causa a ocorrência de interferência, resultando em baixa capacidade de transmissão, enquanto a subutilização de recursos limita a capacidade total de transmissão de dados. Uma solução para controlar a potência de transmissão, atribuir os recursos de rádio e garantir o serviço aos usuários é essencial. Nesta dissertação, é proposto um algoritmo adaptativo de Monte Carlo para realizar alocação global de recursos de forma eficiente em termos de energia, para arquiteturas Heterogeneous Cloud Radio Access Network (H-CRAN), projetadas como futuras redes de quinta geração (5G). Uma solução eficiente para a alocação de recursos em cenários de alta e baixa densidade é proposta. Nossas contribuições são triplas: (i) proposta de uma abordagem global para o problema de atribuição de recursos de rádio na arquitetura HCRAN, cujo caráter estocástico garante uma amostragem geral de espaço de solução; (ii) uma comparação crítica entre nossa solução global e um modelo local; (iii) a demonstração de que, para cenários de alta densidade, a Eficiência Energética não é uma medida adequada para alocação eficiente, considerando a capacidade de transmissão, justiça e total de usuários atendidos. Além disso, a proposta é comparada em relação a três algoritmos de alocação de recursos de última geração para redes 5G. / Up until 2020 it is expected that cellular networks must raise the coverage area in 10-fold, support a 100-fold more user equipments, and increase the data rate capacity by a 1000-fold in comparison with current cellular networks. The dense deployment of small cells is considered a promising solution to reach such aggressive improvements, once it moves the antennas closer to the users, achieving higher data rates due to the signal quality at short distances. However, operating a massive number of antennas can significantly increase the energy consumption of the network infrastructure. Furthermore, the large insertion of new radios brings greater spectral interference between the cells. In this scenery, the optimal management of radio resources turn an exaction due to the impact on the quality of service provided to the users. For example, low transmission powers can leave users without connection, while high transmission powers can contribute to inter radios interference. Furthermore, the interference can be raised on the unplanned reuse of the radio resources, resulting in low data transmission per radio resource, as the under-reuse of radio resources limits the overall data transmission capacity. A solution to control the transmission power, assign the spectral radio resources, and ensure the service to the users is essential. In this thesis, we propose an Adaptive Monte Carlo algorithm to perform global energy efficient resource allocation for Heterogeneous Cloud Radio Access Network (HCRAN) architectures, which are forecast as future fifth-generation (5G) networks. We argue that our global proposal offers an efficient solution to the resource allocation for both high and low density scenarios. Our contributions are threefold: (i) the proposal of a global approach to the radio resource assignment problem in H-CRAN architecture, whose stochastic character ensures an overall solution space sampling; (ii) a critical comparison between our global solution and a local model; (iii) the demonstration that, for high density scenarios, Energy Efficiency is not a well suited metric for efficient allocation, considering data rate capacity, fairness, and served users. Moreover, we compare our proposal against three state-of-the-art resource allocation algorithms for 5G networks.

Notre thèse tente de répondre à la question suivante : « Dans un contexte intégrant des caractéristiques identiques favorables à une réduction ou une modération de la consommation d’énergie domestique, celui du logement social locatif ayant fait l’objet d’un programme de réhabilitation thermique, tous les individus ont-ils des pratiques énergétiques semblables et quels sont les facteurs explicatifs de ces pratiques et de leurs possibles différences ? Dans un premier temps, considérant que l’on ne consomme pas de l’énergie pour elle-même mais pour produire un service par le moyen obligé d’un bien de service de l’énergie, nous avons identifié les pratiques des ménages en introduisant une classification selon qu’elles induisent une consommation ou, à l’inverse, une réduction de la consommation. A côté des pratiques d’acquisition d’équipement et de leur usage, nous avons également relevé des pratiques alternatives ou impliquant des tiers ayant pour effet induit une réduction de consommation. Dans un deuxième temps, nous avons repéré divers facteurs sous-tendant ces pratiques que nous avons regroupés en quatre catégories distinctes : l’identité y apparait comme centre intégrateur jouant un rôle clé. Sur ces bases, nous avons établi un profil pour chaque individu, rendant compte d’un alignement de caractéristiques favorables et défavorables à une réduction de consommation. Dans un troisième temps, nous avons pu repérer des similitudes entre profils, peu corrélées aux classifications statistiques habituelles, d’où nous avons extrapolé quatre types distincts. Ces fortes différences entre profils des individus, dont l’identité constitue le pivot, meten évidence la nécessité de leur prise en compte dans une perspective opérationnelle. Notre thèse interroge le modèle de consommation et de vie en société, ouvre des pistes vers la consolidation de l’efficacité énergétique, vers la sobriété en équipements, et l’enrichissement des identités sociales relationnelles. / This thesis aims to answer the following question: In a context integrating similar technical characteristics favorable to a reduction or moderation of household energy consumption, within a rental social housing project that was recently the object of a thermal rehabilitation program, do all the individuals display similar energy practices, and what are the explanatory factors for these practices and their differences, if any? Firstly, considering that energy is not consumed for itself but for producing a service by means of the consumption of various energy generating goods, we identified the household’s practices by introducing a classification of these practices according to whether they lead to an increase or to a reduction in consumption. Regarding practices of equipment acquisition and their use, we also have identified practices involving third parties as well as alternative practices leading to a reduction in consumption. Secondly, we identified various factors underlying these practices which we were able to group into four different categories among which identity appears as an integrating factor playing a key role. On these bases, we established a profile for each individual, showing a certain alignment of the characteristics that are either favorable or unfavorable to reduced consumption. Thirdly, we observed similarities between the profiles, weakly correlated with the usual statistical classifications, from which we have extrapolated four truly different types. These strong differences between individuals’ profiles, whose identity constitutes the pivot,highlights the importance of their consideration in an operational perspective. The thesis questions the pattern of consumption and life in our society and opens perspectives towards the consolidation of energy efficiency, towards moderation in equipment use, and towards the enrichment of relational social identities.

A pesquisa propõe avaliar quantitativamente a eficácia do emprego de estratégias passivas em um bloco cirúrgico hospitalar para a redução do consumo de energia elétrica com fins de arrefecimento do ar. A partir do estudo da conformação histórica do edifício hospitalar e da identificação das unidades funcionais em que é obrigatório o uso de ar condicionado; das características de geração e consumo de energia elétrica no Brasil e potenciais de economia energética em edificações, com foco em hospitais; seguidos do estabelecimento de conceitos básicos de térmica de edificações, estabeleceu-se o embasamento teórico para a realização de estudos de caso na cidade de Belo Horizonte, Minas Gerais. A análise comparativa dos dados de área física, sistemas de iluminação artificial, climatização e equipamentos coletados em seis blocos cirúrgicos possibilitou a seleção de uma unidade para construção de modelo computacional e realização de simulações em software de análise de desempenho térmico e energético de edificações. Os resultados alcançados demonstraram a importância de se considerar as condições bioclimáticas locais, em especial o controle da insolação direta, bem como reforçaram a concepção de que o projeto arquitetônico pode contribuir para a eficiência energética da edificação, mesmo quando é obrigatório o uso de ar condicionado. A realização de simulações computacionais se mostrou vantajosa, visto que possibilita a comparação de diversas opções de projeto com objetividade, antes de sua efetiva implementação. / The research quantitatively evaluate the effectiveness of the use of passive strategies in a surgical ward for reducing energy consumption for the purpose of air-cooling. The study of the historic conformation of the hospital building and the identification of the functional units in which it is mandatory the use of air conditioning; the characteristics of generation and consumption of electricity in Brazil and potential energy savings in buildings, focusing on hospitals; followed by the review of basic concepts of building heat transfer, established the theoretical basis for conducting case studies in the city of Belo Horizonte, Minas Gerais. A comparative analysis of physical area, artificial lighting, air conditioning systems and equipment data collected in six surgical wards enabled the selection of one unit to build a computational model and run simulations with the use of a software for thermal and energy performance of buildings. The results demonstrated the importance of considering local bioclimatic conditions, in particular the control of direct sunlight, as well as reinforced the concept that architectural design can contribute to the energy efficiency of the built environment, even when the use of air conditioning is mandatory. Performing computer simulations proved advantageous, since it enables objective comparison of different design options before its effective implementation.