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TITLE : NETWORK ORCHESTTRATION FOR ENVIRONMENAL SUSTAINBILITY; A CASE OF PUBLIC TRANSPORT SERVICES. / NETWORK ORCHESTTRATION FOR ENVIRONMENAL SUSTAINBILITY; A CASE OF PUBLIC TRANSPORT SERVICES.Usama, Muhammad, Khan, Zohaib January 2013 (has links)
the hub firms which happen to be the central leading body carrying out responsibilities as a hub firm. The network orchestration comprises three vital orchestration processes Knowledge Mobility, Innovation Appropability and Network Stability which help the network orchestrator to communicate with multiple actors in the network. The research work is based on reflection and analysis of performance of hub firm in perspective of network orchestration and innovation project directed towards betterment of public transportation department. With respect to the domain of study there have been thorough perusal and analysis of several academic articles and resources which have hitherto been contributed for the subject in question. Methodology consists of in depth interview of the researchers of Victoria institute which are currently working on ISET program (Innovation for sustainable everyday travel). Our findings seek to answer the main question, that how a hub firm tackles with its emerging challenges to leverage network innovation, in shape of evidences from Viktoria Institute of research and development. Analysis of data is carried out through strategic management tool and descriptive approach. With all due efforts, the work has been afforded with validity and authenticity employing all the requisite elements as per social research is concerned. Discussion follows the analysis and results have been illustrated accordingly.
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Damping of sub-synchronous control interactions with a STATCOM : Wind farms & series compensated power linesAlvarez Urrutia, Leonardo January 2022 (has links)
The power converter is one of the key components in power system applications such as high voltage direct current (HVDC) systems and the grid connection of intermittent sources such as wind and solar power. However, the increased penetration of converter-based generation introduces challenges, such as sub-synchronous interaction between the converter control system and the grid. These control interactions are characterized by fast-growing, subsynchronous oscillations (SSO). This thesis deals with the analysis of sub-synchronous control interactions (SSCI) between doubly-fed induction generator (DFIG)-based wind farms and series compensated transmission lines. Moreover, the thesis aims to identify a method for mitigating the sub-synchronous oscillations using a static synchronous compensator (STATCOM), with a supplementary damping controller. The study is based on work in PSCAD/EMTDC and uses a system based on the IEEE first benchmark model, acting as a grid, and the scaled power output of a DFIG turbine model, modeling a wind farm. Initial impedance-based analysis in the frequency domain shows that the DFIG wind farm has a negative resistance throughout the sub-synchronous frequency range. A negative resistance may result in negative damping of the system and further introduce the risk of instability. The wind farm resistance and, in turn, system stability is affected by the current control loop of the DFIG-converter. The transmission line compensation factor largely impacts the system stability, while the power output has a minor effect. A time-domain analysis is performed to verify the result of the frequency domain analysis. Further on, a grid-forming STATCOM is added to the system for VAr compensation. Additional stability analysis shows that even though improvingthe stability, the STATCOM alone is not adequate to mitigate the SSCI. The proposed damping strategy is based on modifying the STATCOM voltage reference andcan be divided into three steps: detecting the SSO, estimating the sub-synchronous component, and modifying the extracted signal. The detection algorithm is based on a half-cycle comparator, while the modification is done through a proportional gain. When estimating the sub-synchronous components, two methods are proposed and compared. The first estimation method is based on a conventional power system stabilizer (PSS) method, and the second is afilter-less method.
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Aid System for Finding Trapped Earthquake VictimsSchillén, Anton January 2017 (has links)
Using Emsuch [6] as a base this reports tries to find a solution to the problems that arise when trying to find survivors in collapsed buildings following an earthquake. Emsuch is a system that allows an user to retrieve information from the Home unit inside a house after an earthquake. But the results of the previous study [6] showed that the previous Emsuch is not very useful in disasters such as earthquakes. This is due to several reasons that were overlooked in that study such as electricity consumption and connectivity. So this study aims to improve the system by designing software that enables the user to quickly check each household that uses an Emsuch system. By using a case study and interviewing members of the Japanese Ground Self-Defence Forces a requirements document was created. From these requirements the system was designed to fulfil them all and then partly implemented and tested. The current prototype of the system has some major parts working, with a few parts non-functional or unimplemented. / Den här rapporten använder Emsuch-systemet [6] för att försöka lösa de problem som uppstår när armén letar efter överlevare i husmassor efter jordbävningar i Japan. Med Emsuch kan räddningsarbetarna hämta information från husen de går förbi under letandet. Under en tidigare studie [6] där grunden till systemet utvecklades identifierades flera punkter som leder till problem i de förhållanden som råder i de räddningsaktionerna. De två största utmaningarna är bristen på el och att infrastrukturen för kommunikation ofta är nere. Den här rapporten avser att utforma och implementera en lösning som gör att användarna i armén kan ansluta sig till varje enhet i förbifarten. Med en fallstudie som inkluderar en intervju med Japans markbaserade försvarsstyrkor i Sapporo togs ett kravdokument fram. Detta kravdokument användes som grund för implementeringen av systemet. En prototyp togs fram och testades delvis. Resultatet av testerna visade att Emsuch har potential för att användas i räddningsarbeten, men att det är flera delar som behövs fixas för att klara av verkliga situationer.
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Precificação em orquestradores de informação: maximizando redes estáveisLustosa, Bernardo Carvalho 13 August 2013 (has links)
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Previous issue date: 2013-08-13 / Em redes de inovação baseadas em trocas de informação, o agente orquestrador se apropria das informações dos atores periféricos, gera inovação e distribui em forma de valor agregado. É sua função promover a estabilidade na rede fazendo com que a mesma tenha taxas não negativas de crescimento. Nos mercados de análise de crédito e fraude, por exemplo, ou bureaus funcionam como agentes orquestradores, concentrando as informações históricas da população que são provenientes de seus clientes e fornecendo produtos que auxiliam na tomada de decisão. Assumindo todas as empresas do ecossistema como agentes racionais, a teoria dos jogos se torna uma ferramenta apropriada para o estudo da precificação dos produtos como mecanismo de promoção da estabilidade da rede. Este trabalho busca identificar a relação de diferentes estruturas de precificação promovidas pelo agente orquestrador com a estabilidade e eficiência da rede de inovação. Uma vez que o poder da rede se dá pela força conjunta de seus membros, a inovação por esta gerada varia de acordo com a decisão isolada de cada agente periférico de contratar o agente orquestrador ao preço por ele estipulado. Através da definição de um jogo teórico simplificado onde diferentes agentes decidem conectar-se ou não à rede nas diferentes estruturas de preços estipuladas pelo agente orquestrador, o estudo analisa as condições de equilíbrio conclui que o equilíbrio de Nash implica em um cenário de estabilidade da rede. Uma conclusão é que, para maximizar o poder de inovação da rede, o preço a ser pago por cada agente para fazer uso da rede deve ser diretamente proporcional ao benefício financeiro auferido pela inovação gerada pela mesma. O estudo apresenta ainda uma simulação computacional de um mercado fictício para demonstração numérica dos efeitos observados. Através das conclusões obtidas, o trabalho cobre uma lacuna da literatura de redes de inovação com agentes orquestradores monopolistas em termos de precificação do uso da rede, servindo de subsídio de tomadores de decisão quando da oferta ou demanda dos serviços da rede. / In innovation networks based on information exchange, the orchestrating actor, or hub, captures information from the peripherical actors, promotes innovation and then distributes it for the network in the form of added value. Orchestration comprises promoting the network’s stability in order to avoid negative growth rates. The credit and fraud agencies, for example, can be understood as orchestrating hubs, concentrating the historical information of the population generated by their clients and offering products that support decision making. Assuming all the companies of this ecosystem as rational agents, game theory emerges as an appropriate framework for the study of pricing as a mechanism to promote the network’s stability. The present work focuses on the identification of a relationship between the different pricing options that can be proposed by the orchestrating hub and the network’s stability and efficiency. Since the network power is given by the combined strength of its members, the innovation generated is a function of the isolated decision of each peripherical agent on whether to hire the orchestrating hub’s services for the price defined by the latter. Through the definition of a simplified theoretical game in which agents decide whether to connect or not to the network based on the pricing structure defined by the hub, the present study analyzes the equilibrium conditions and concludes that the Nash equilibrium entails the network’s stability. One of the conclusions is that in order to maximize the innovation power of the network, the agents should be charged a price that is proportional to the financial benefit obtained by the innovation generated by the net. The study presents as well a computer simulation of a fictitious market for a numerical demonstration of the observed effects. With these conclusions, the present study fills a gap in the literature on monopolistic orchestrated innovation in terms of the pricing structures of the network connection and its use. It can be used as a basis for decision making both on the supply and the demand sides of the services of the hub.
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Stability analysis of new paradigms in wireless networksKangas, M. (Maria) 02 June 2017 (has links)
Abstract
Fading in wireless channels, the limited battery energy available in wireless handsets, the changing user demands and the increasing demand for high data rate and low delay pose serious design challenges in the future generations of mobile communication systems. It is necessary to develop efficient transmission policies that adapt to changes in network conditions and achieve the target delay and rate with minimum power consumption.
In this thesis, a number of new paradigms in wireless networks are presented. Dynamic programming tools are used to provide dynamic network stabilizing resource allocation solutions for virtualized data centers with clouds, cooperative networks and heterogeneous networks. Exact dynamic programming is used to develop optimal resource allocation and topology control policies for these networks with queues and time varying channels. In addition, approximate dynamic programming is also considered to provide new sub-optimal solutions.
Unified system models and unified control problems are also provided for both secondary service provider and primary service provider cognitive networks and for conventional wireless networks. The results show that by adapting to the changes in queue lengths and channel states, the dynamic policy mitigates the effects of primary service provider and secondary service provider cognitive networks on each other.
We investigate the network stability and provide new unified stability regions for primary service provider and secondary service provider cognitive networks as well as for conventional wireless networks. The K-step Lyapunov drift is used to analyse the performance and stability of the proposed dynamic control policies, and new unified stability analysis and queuing bound are provided for both primary service provider and secondary service provider cognitive networks and for conventional wireless networks. By adapting to the changes in network conditions, the dynamic control policies are shown to stabilize the network and to minimize the bound for the average queue length. In addition, we prove that the previously proposed frame based does not minimize the bound for the average delay, when there are shared resources between the terminals with queues. / Tiivistelmä
Langattomien kanavien häipyminen, langattomien laitteiden akkujen rajallinen koko, käyttäjien käyttötarpeiden muutokset sekä lisääntyvän tiedonsiirron ja lyhyemmän viiveen vaatimukset luovat suuria haasteita tulevaisuuden langattomien verkkojen suunnitteluun. On välttämätöntä kehittää tehokkaita resurssien allokointialgoritmeja, jotka sopeutuvat verkkojen muutoksiin ja saavuttavat sekä tavoiteviiveen että tavoitedatanopeuden mahdollisimman pienellä tehon kulutuksella.
Tässä väitöskirjassa esitetään uusia paradigmoja langattomille tietoliikenneverkoille. Dynaamisen ohjelmoinnin välineitä käytetään luomaan dynaamisia verkon stabiloivia resurssien allokointiratkaisuja virtuaalisille pilvipalveludatakeskuksille, käyttäjien yhteistyöverkoille ja heterogeenisille verkoille. Tarkkoja dynaamisen ohjelmoinnin välineitä käytetään kehittämään optimaalisia resurssien allokointi ja topologian kontrollointialgoritmeja näille jonojen ja häipyvien kanavien verkoille. Tämän lisäksi, estimoituja dynaamisen ohjelmoinnin välineitä käytetään luomaan uusia alioptimaalisia ratkaisuja.
Yhtenäisiä systeemimalleja ja yhtenäisiä kontrollointiongelmia luodaan sekä toissijaisen ja ensisijaisen palvelun tuottajan kognitiivisille verkoille että tavallisille langattomille verkoille. Tulokset osoittavat että sopeutumalla jonojen pituuksien ja kanavien muutoksiin dynaaminen tekniikka vaimentaa ensisijaisen ja toissijaisen palvelun tuottajien kognitiivisten verkkojen vaikutusta toisiinsa.
Tutkimme myös verkon stabiiliutta ja luomme uusia stabiilisuusalueita sekä ensisijaisen ja toissijaisen palveluntuottajan kognitiivisille verkoille että tavallisille langattomille verkoille. K:n askeleen Lyapunovin driftiä käytetään analysoimaan dynaamisen kontrollointitekniikan suorituskykyä ja stabiiliutta. Lisäksi uusi yhtenäinen stabiiliusanalyysi ja jonon yläraja luodaan ensisijaisen ja toissijaisen palveluntuottajan kognitiivisille verkoille ja tavallisille langattomille verkoille. Dynaamisen algoritmin näytetään stabiloivan verkko ja minimoivan keskimääräisen jonon pituuden yläraja sopeutumalla verkon olosuhteiden muutoksiin. Tämän lisäksi todistamme että aiemmin esitetty frame-algoritmi ei minimoi keskimääräisen viiveen ylärajaa, kun käyttäjät jakavat keskenään resursseja.
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