Smart grid is about integration of distributed energy resources (DERs) into the energy systems, especially electricity grid. DERs include renewable energy resources such as wind and solar, energy storages such as electrical and thermal energy storage, demand response programs, smart homes, and electric vehicles with their charging stations. DERs have significant advantages such as reduction of operation costs, emission, and peak as well as the increase of reliability, resiliency, stability, and voltage profile in smart grids. They also prevent establishment of fossil fuel power plants and expansion of transmission lines by locating in electricity distribution grid and transmission lines. The advantages approve the financial, technical, and environmental effects of the DERs in smart grids. An operation/planning approach such as EHs/IEHs is required to utilization of DERs in the Smart Grid. EH is a super node in electricity power system which connects different energy networks such as gas, electricity, heating, or cooling. The EH can be developed by DERs for operation and planning purposes. The EHs can be located in different parts of the energy networks to form IEHs. Despite the significant advantages of utilization of DERs in EHs of Smart Grids, they should be utilized by information and communication technologies (ICTs), which results in Cyber-Physical Power Systems (CPPSs) vulnerable to different cyberattacks. The vulnerability of DERs in EHs of Smart Grid leads to jeopardizing the reliability, stability, and resiliency of power systems since integrity, confidentiality, or availability cyberattacks might bypass the detection systems to take control of DERs for malicious purposes such as congestion, cascading failure, blackout, undervoltage/overvoltage, or costs. In this research, some cyberattacks are modeled on DERs in EHs and IEHs of Smart Grid, and the vulnerabilities of DERs to the cyberattacks in the developed EHs/IEs are approved: First, an integrity cyberattack is modeled and applied to the DR program (time/incentive-based) in the developed EH in electricity distribution grid in order to control the performance of the EH and its negative effects on the grid. The attacker aims to manipulate the system by both raising peak demand and lowering customers' energy bills simultaneously. This strategy is designed to deceive customers into participating in falsified Demand Response (DR) programs, ultimately leading to an increase in the overall peak demands of the system which jeopardizes the reliability of the system. Second, an integrity FDI cyberattack is modeled and applied on the developed IEHs in transmission lines in order to control the performance of the IEH and its negative effects on the transmission lines. This cyberattack is modeled to manipulate the transmission lines energy demands in order to threaten reliability and stability of the system by bypassing detection systems. Finally, the attacker targets the developed EHs integrated by DERs by maximizing the costs associated with operation, emission, and energy not supplied costs. The attacker objective is to adversely affect the financial, technical, and environmental advantages of integration of DERs to the system. Hence, powerful remedial actions are required to alleviate the adverse effects of DERs, manipulated by attackers, in the developed EHs. Therefore, a remedial action is designed by min-max formulation in order to mitigate the adverse effects of DERs on financial, technical, and environmental terms. The remedial action reduces the imposed costs by changing the status of EH devices. The results highlight the role of DERs in reducing costs and emphasize the need for their proactive security measures in cyber-physical power systems.

Nous avons récemment mis en évidence des neurones GABAergiques jouant un rôle de « hub » dans l'hippocampe immature, orchestrant la synchronisation neuronale via une arborisation axonale dense. Dans ma thèse, j'ai d'abord montré, grâce à des enregistrements électrophysiologiques par paires, que les hubs étaient connectés à de nombreux neurones par des synapses GABAergiques fonctionnelles (Bonifazi et al. 2009). Puis, en utilisant des souris mutantes conditionnelles où les neurones sont marqués en fonction de leur origine embryonnaire, j'ai démontré que les neurones GABAergiques générés le plus tôt formaient une famille de hubs. Ces neurones sont toujours présents chez l'adulte et deviennent des neurones GABAergiques de projection extrahippocampique. Ceci suggère que la fonction de ces neurones serait maintenue, du moins anatomiquement, au stade adulte. / We have recently demonstrated the existence of functional hubs driving network synchronizations in the developing hippocampus. Hubs are a subpopulation of GABAergic neurons displaying widespread axonal projections. During my PhD, using paired electrophysiological recordings, I have shown that hub cells are synaptically connected to a large number of neurons (Bonifazi et al. 2009). Next, using genetic fate mapping approaches, I have demonstrated that early born GABAergic neurons constitute a subpopulation of hub cells. These pioneer hub cells remain into adulthood and develop into GABAergic neurons with an extrahippocampal projection (Picardo et al. 2011). This suggests that hub function may to retained into adulthood, at least structurally.

[pt] As mudanças na regulamentação mundial do transporte aéreo, observadas nas últimas duas décadas, trouxeram tanto um desafio como um estímulo aos sistemas de distribuição de mercadorias, com ampliação dos volumes transportados, associado à redução de distâncias. Com isso, a competição obrigou as companhias aéreas a serem mais eficientes. Nesse aspecto, a utilização de pontos consolidadores de carga em suas redes de transporte, os hub, passaram a ser uma opção de redução de custos e otimização dos recursos operacionais. O presente trabalho tomou como base os dados do Departamento de Aviação Civil (DAC) para transporte de carga entre os 32 aeroportos de carga brasileiros, como também sua agregação nas cinco regiões geográficas do País. A formulação agregada serviu como teste para um futuro estudo que envolveria todos os aeroportos. A aplicação piloto evita usar um modelo de otimização, fazendo uma enumeração de todas as alternativas, com apoio de uma planilha de dados, de modo a identificarse um único hub. / [en] The changes in air transportation regulation implemented in the last two decades, brought both a challenge and a stimulus to the merchandise distribution systems, with a sizable increase in the transported volumes and a reduction in travelled distances. As a consequence, competition imposes more efficiency to the air companies. The cargo consolidation points in the transport network, the hub, are a definite requirement for cost reduction and optimization of their operational assets. The present research has collected data in Departamento de Aviação Civil (DAC) about the 32 Brazilian cargo airports as well as its aggregation among the five geographic regions of the country. The aggregated formulation was used as a test for a future study including all airports. The pilot application avoids the use of an optimization model but rather, using an Excel software, makes total enumeration of all alternatives to find a single hub proposal.

In this dissertation, I investigate hub carriers' competitive advantage in directional markets within their hub and spoke networks. In the first chapter, I examine whether the competitive advantage of hub carriers in attracting hub-to-spoke passengers relative to spoke-to-hub passengers affects rivals' entry decisions in a symmetric way. The hub carrier advantage in attracting passengers at its concentrated hub airport creates an environment in which variation in the composition of demand in hub-to-spoke markets affects entry in a profoundly different way than demand variation in spoke-to-hub markets. In the second chapter, I examine hub carrier fares and price-cost margins in hub and spoke airport pairs. Exploiting variation across airport-pairs, I find that an increase in the proportion of business travelers in hub-to-spoke markets increases fares in these markets, while an increase in the proportion of business travelers in spoke-to-hub markets decreases fares. This result is consistent with the structural asymmetries found in the first chapter. However, the source of these concentration advantages remains ambiguous. These advantages could be due to cost benefits, demand effects, or market power. Exploiting the variation between hub-to-spoke and spoke-to-hub markets within airport pairs isolates the market power effect on fares. I find that difference in hub carrier airport shares explains most of the variation in its hub-to-spoke and spoke-to-hub price-cost margins. Unobserved quality and cost heterogeneity do not bias the result. In the final chapter we look at the relationship between market power and price discrimination. In the presence of price discrimination, at least one price does not equal marginal cost. Therefore, if price discrimination exists, there must be market power. While this logic is sound, it has led many policymakers to believe that price discrimination and market power are positively correlated. We present a model where measured price-discrimination can be low while market power is high and price discrimination can be high while market power is low, thus demonstrating that there is no theoretical connection between the strength of price discrimination and that of market power. We then present new evidence that price discrimination is negatively correlated with market power in the US airlines industry. / text

Electric power distribution systems are gradually adopting new advancements in communication, control, measurement, and metering technologies to help realize the evolving concept of Smart Grids. Future distribution systems will facilitate increased and active participation of customers in Demand Side Management activities, with customer load profiles being primarily governed by real-time information such as energy price, emission, and incentive signals from utilities. In such an environment, new mathematical modeling approaches would allow Local Distribution Companies (LDCs) and customers the optimal operation of distribution systems and customer's loads, considering various relevant objectives and constraints. This thesis presents a mathematical model for optimal and real-time operation of distribution systems. Thus, a three-phase Distribution Optimal Power Flow (DOPF) model is proposed, which incorporates comprehensive and realistic models of relevant distribution system components. A novel optimization objective, which minimizes the energy purchased from the external grid while limiting the number of switching operations of control equipment, is considered. A heuristic method is proposed to solve the DOPF model, which is based on a quadratic penalty approach to reduce the computational burden so as to make the solution process suitable for real-time applications. A Genetic Algorithm based solution method is also implemented to compare and benchmark the performance of the proposed heuristic solution method. The results of applying the DOPF model and the solution methods to two distribution systems, i.e., the IEEE 13-node test feeder and a Hydro One distribution feeder, are discussed. The results demonstrate that the proposed three-phase DOPF model and the heuristic solution method may yield some benefits to the LDCs in real-time optimal operation of distribution systems in the context of Smart Grids. This work also presents a mathematical model for optimal and real-time control of customer electricity usage, which can be readily integrated by industrial customers into their Energy Hub Management Systems (EHMSs). An Optimal Industrial Load Management (OILM) model is proposed, which minimizes energy costs and/or demand charges, considering comprehensive models of industrial processes, process interdependencies, storage units, process operating constraints, production requirements, and other relevant constraints. The OILM is integrated with the DOPF model to incorporate operating constraints required by the LDC system operator, thus combining voltage optimization with load control for additional benefits. The OILM model is applied to two industrial customers, i.e., a flour mill and a water pumping facility, and the results demonstrate the benefits to the industrial customers and LDCs that can be obtained by deploying the proposed OILM and three-phase DOPF models in EHMSs, in conjunction with Smart Grid technologies.

[pt] O ambiente baseado em hyperlink possui na sua topologia informações substanciais sobre o seu conteúdo. Baseado nesse tipo de ambiente, Jon Kleingerg desenvolveu um conjunto de algoritmos, popularmente conhecido como HITS (Hyperlink Induced Topic Search), que utiliza a estrutura de hyperlinks na WWW para extrair essas informações. O foco central desses algoritmos é a classificação de tópicos de busca de caráter geral na WWW, através da descoberta de páginas que representam autoridade sobre tais tópicos. Para tanto, os algoritmos formulam a noção de autoridade considerando o relacionamento, decorrente da estrutura de hyperlink, entre o conjunto de páginas que são autoridades relevantes e o conjunto de páginas que apontam para essas, denominadas de hubs. Jon Kleingerg definiu, portanto, uma relação de interdependência entre os conjuntos anteriormente citados: uma boa autoridade será uma página apontada por bons hubs e um bom hub será uma página que aponta para boas autoridades. Neste trabalho, propomos a extensão do modelo formulado por Jon Kleingerg, através da inserção de novos conceitos nas relações de interdependência entre autoridades e hubs. Assim, formulamos um algoritmo estendido, XHITS (Extended Hyperlink Induced Topic Search), que visa melhorar a classificação das autoridades do ambiente. Nessa extensão as autoridades são apontadas por bons hubs, às vezes apontadas por bons portais e também apontam para boas novidades. Os bons hubs são páginas que apontam para boas autoridades e novidades, e são apontados por bons portais. As boas novidades são páginas que são apontadas pelas boas autoridades, pelos bons hubs e pelos bons portais e bons portais são páginas que apontam para as boas autoridades, para bons hubs e para boas novidades. Adicionalmente, mostramos que o algoritmo proposto converge e também os diversos resultados experimentais que indicam a melhoria na precisão dos hiperdocumentos recuperados. / [en] The network structure of a hyperlinked environment can be a rich source of information about the content of this environment. Jon Kleinberg developed a set of algorithms, called HITS (Hyperlink Induced Topic Search), for extracting information from the hyperlink structures of those environments. The aim of these algorithms is the distillation of broad search topics, through the discovery of related authoritative information sources. The notion of authority is based on the hyperlink structure relationship between a set of relevant authoritative pages and the set of hubs. Thus, hubs and authorities exhibit what could be called a mutually reinforcing relationship: a good hub is a page that points to many good authorities; a good authority is a page that is pointed by many good hubs. In this work, we present the XHITS (Extended Hyperlink Induced Topic Search) algorithm, an extension of the HITS algorithm by introducing new concepts on the mutually reinforcing relationship. In XHITS, a good authority is a page that is pointed by many good hubs, some good portals and points to good novels; a good hub is a page that points to many good authorities, some good novels and is pointed by some good portals; and a good novel is a page that is pointed by good authorities, some good hubs and some good portals; a good portal is a page that points to some good authorities, some good hubs and some good novels. In addition, we show that XHITS converges and, through some experiments, the improved quality of the hyper documents retrieved.

Orientador: Juliano Maurício de Carvalho / Resumo: A tese analisa o fenômeno dos hubs criativos e seus efeitos no desenvolvimento da Indústria de Jogos Digitais (IJD). O procedimento metodológico é a construção de teorias através de estudos de caso. A coleta de dados se faz por meio de pesquisa documental em websites e relatórios públicos dos 69 hubs criativos da IJD mapeados em todo o mundo. A coleta também envolve entrevistas semiestruturadas on-line e presenciais com gestores dos hubs, e pesquisa de campo com observações diretas. O estudo descreve a estrutura global da IJD e analisa suas implicações nos clusters criativos locais. Mapeia e sistematiza os hubs criativos da IJD, descreve e classifica as ações realizadas por esses hubs. Estuda o caso do hub Dutch Game Garden como exemplo destas iniciativas. A partir dos dados levantados e sistematizados, são formuladas hipóteses, analisadas à luz da literatura. Como resultado, é construída uma série de premissas teóricas a respeito dos hubs criativos da IJD. São elas: os hubs criativos podem ampliar a proximidade entre os agentes de um cluster; a colaboração é essencial para o sucesso de um hub criativo; a eficiência das ações realizadas pelo hub criativo está relacionada ao grau de maturidade do cluster em que ele está localizado; os hubs criativos ocupam o papel de intermediários nas cidades criativas; e as ações dos hubs são capazes de catalisar o desenvolvimento de clusters criativos da Indústria de Jogos Digitais. / Abstract: The thesis analyzes the phenomenon of creative hubs and their effects on the development of the Digital Games Industry (DGI). The methodological procedure is the construction of theories through case studies. Data collection was done through documentary research on websites and public reports of 69 creative DGI hubs mapped around the world. The collection also involves semi-structured online and in-person interviews with managers of the hubs, and field research with direct observations. The study describes the global structure of the DGI and analyzes its implications for local ecosystems. Maps and systematizes DGI's creative hubs, describes and classifies the actions carried out by these hubs. It studies the case of the Dutch Game Garden hub as an example of these initiatives. Based on the data collected and systematized, hypotheses are formulated and analyzed in the light of the literature. As a result, a series of theoretical assumptions are made about DGI's creative hubs. They are: creative hubs can expand the proximity between agents in a cluster; collaboration is essential to the success of a creative hub; the efficiency of the actions carried out by the creative hub is related to the degree of maturity of the cluster in which it is located; creative hubs play the role of intermediaries in creative cities; and the actions of the hubs are able to catalyze the development of creative clusters in the Digital Games Industry. / Doutor

Utvecklingen av förbandsmetoder är viktigt för att utveckla konstruktionslösningar. Under det senaste decenniet har forskning på limmade förband utförts, främst på inlimning av stålstag och plattstål i limträ. Förhoppningen är att spänningen ska fördelas jämnare i förbandet och att brott ska kunna undvikas. Hypotetiskt sett skulle det kunna göra knutpunker utan synliga förband möjliga vilket även skulle gynna arkitekternas önskemål. Genom en sammanställning av tidigare forskning dras en jämförelse mellan testresultaten och en antagen knutpunkt som belastas av egentyngder och variabla laster. På så sätt kan limmets kapacitet konkretiseras. Även problematik som uppstår och förutsättningar som måste utvecklas redovisas. / The development of joints for wood structures has been under progress during the last decade, and research has mainly been done on glued in steel rods and inner steel plate joints. The aim of this report is to find a way to get a better shear resistance to prevent timber structures from breaking during high risk circumstances, such as loads caused by exceptional weather. Structures without visible joints would also benefit the architects' wishes, which would be a reason to develop the technique of joints for wood structures. By a compiling of previous research, a comparison between test results and a joint of a hypothetical building is made. The loads that affect the calculations of the joint are snow-, wind-, variable and structural loads. This concretises the capacity of the adhesive joint. Also problems that appear and preconditions that have to be developed are recited.

Food Hubs are in a unique yet precarious position to help the local food movement reform unsustainable aspects of the conventional food system but they themselves face challenges in strategic planning and managing growth. Due to the lack of consensus on what local food’s values are, the construction of meaning and the local food movement itself is at risk of being coopted by the very systems it seeks to reform. This research aims to explain the role of key stakeholders and their impact on the local food movement through a sequential explanatory design which seeks to answer the questions of who and what really counts among Food Hub stakeholders. Relying on stakeholder theory, stakeholder salience and social movement frameworks, the research has shown that Food Hubs consider their internal and customer stakeholders as highly important to strategic planning, yet could work more effectively at engaging regulatory and community stakeholders to construct and advance their own objectives as well as those of the local food movement.

<p>Individual proteins, and small collections of proteins, have been extensively studied for at least two hundred years. Today, more than 350 genomes have been completely sequenced and the proteomes of these genomes have been at least partially mapped. The inventory of protein coding genes is the first step toward understanding the cellular machinery. Recent studies have generated a comprehensive data set for the physical interactions between the proteins of <i>Saccharomyces cerevisiae</i>, in addition to some less extensive proteome interaction maps of higher eukaryotes. Hence, it is now becoming feasible to investigate important questions regarding the evolution of protein-protein networks. For instance, what is the evolutionary relationship between proteins that interact, directly or indirectly? Do interacting proteins co-evolve? Are they often derived from each other? In order to perform such proteome-wide investigations, a top-down view is necessary. This is provided by network (or graph) theory.</p><p>The proteins of the cell may be viewed as a community of individual molecules which together form a society of proteins (nodes), a network, where the proteins have various kinds of relationships (edges) to each other. There are several different types of protein networks, for instance the two networks studied here, namely metabolic networks and protein-protein interaction networks. The metabolic network is a representation of metabolism, which is defined as the sum of the reactions that take place inside the cell. These reactions often occur through the catalytic activity of enzymes, representing the nodes, connected to each other through substrate/product edges. The indirect interactions of metabolic enzymes are clearly different in nature from the direct physical interactions, which are fundamental to most biological processes, which constitute the edges in protein-protein interaction networks.</p><p>This thesis describes three investigations into the evolution of metabolic and protein-protein interaction networks. We present a comparative study of the importance of retrograde evolution, the scenario that pathways assemble backward compared to the direction of the pathway, and patchwork evolution, where enzymes evolve from a broad to narrow substrate specificity. Shifting focus toward network topology, a suggested mechanism for the evolution of biological networks, preferential attachment, is investigated in the context of metabolism. Early in the investigation of biological networks it seemed clear that the networks often display a particular, 'scale-free', topology. This topology is characterized by many nodes with few interaction partners and a few nodes (hubs) with a large number of interaction partners. While the second paper describes the evidence for preferential attachment in metabolic networks, the final paper describes the characteristics of the hubs in the physical interaction network of <i>S. cerevisiae</i>.</p>