942 resultados para topological string
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Master’s Thesis in Computer Engineering
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The use of distribution networks in the current scenario of high penetration of Distributed Generation (DG) is a problem of great importance. In the competitive environment of electricity markets and smart grids, Demand Response (DR) is also gaining notable impact with several benefits for the whole system. The work presented in this paper comprises a methodology able to define the cost allocation in distribution networks considering large integration of DG and DR resources. The proposed methodology is divided into three phases and it is based on an AC Optimal Power Flow (OPF) including the determination of topological distribution factors, and consequent application of the MW-mile method. The application of the proposed tariffs definition methodology is illustrated in a distribution network with 33 buses, 66 DG units, and 32 consumers with DR capacity.
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All over the world, the liberalization of electricity markets, which follows different paradigms, has created new challenges for those involved in this sector. In order to respond to these challenges, electric power systems suffered a significant restructuring in its mode of operation and planning. This restructuring resulted in a considerable increase of the electric sector competitiveness. Particularly, the Ancillary Services (AS) market has been target of constant renovations in its operation mode as it is a targeted market for the trading of services, which have as main objective to ensure the operation of electric power systems with appropriate levels of stability, safety, quality, equity and competitiveness. In this way, with the increasing penetration of distributed energy resources including distributed generation, demand response, storage units and electric vehicles, it is essential to develop new smarter and hierarchical methods of operation of electric power systems. As these resources are mostly connected to the distribution network, it is important to consider the introduction of this kind of resources in AS delivery in order to achieve greater reliability and cost efficiency of electrical power systems operation. The main contribution of this work is the design and development of mechanisms and methodologies of AS market and for energy and AS joint market, considering different management entities of transmission and distribution networks. Several models developed in this work consider the most common AS in the liberalized market environment: Regulation Down; Regulation Up; Spinning Reserve and Non-Spinning Reserve. The presented models consider different rules and ways of operation, such as the division of market by network areas, which allows the congestion management of interconnections between areas; or the ancillary service cascading process, which allows the replacement of AS of superior quality by lower quality of AS, ensuring a better economic performance of the market. A major contribution of this work is the development an innovative methodology of market clearing process to be used in the energy and AS joint market, able to ensure viable and feasible solutions in markets, where there are technical constraints in the transmission network involving its division into areas or regions. The proposed method is based on the determination of Bialek topological factors and considers the contribution of the dispatch for all services of increase of generation (energy, Regulation Up, Spinning and Non-Spinning reserves) in network congestion. The use of Bialek factors in each iteration of the proposed methodology allows limiting the bids in the market while ensuring that the solution is feasible in any context of system operation. Another important contribution of this work is the model of the contribution of distributed energy resources in the ancillary services. In this way, a Virtual Power Player (VPP) is considered in order to aggregate, manage and interact with distributed energy resources. The VPP manages all the agents aggregated, being able to supply AS to the system operator, with the main purpose of participation in electricity market. In order to ensure their participation in the AS, the VPP should have a set of contracts with the agents that include a set of diversified and adapted rules to each kind of distributed resource. All methodologies developed and implemented in this work have been integrated into the MASCEM simulator, which is a simulator based on a multi-agent system that allows to study complex operation of electricity markets. In this way, the developed methodologies allow the simulator to cover more operation contexts of the present and future of the electricity market. In this way, this dissertation offers a huge contribution to the AS market simulation, based on models and mechanisms currently used in several real markets, as well as the introduction of innovative methodologies of market clearing process on the energy and AS joint market. This dissertation presents five case studies; each one consists of multiple scenarios. The first case study illustrates the application of AS market simulation considering several bids of market players. The energy and ancillary services joint market simulation is exposed in the second case study. In the third case study it is developed a comparison between the simulation of the joint market methodology, in which the player bids to the ancillary services is considered by network areas and a reference methodology. The fourth case study presents the simulation of joint market methodology based on Bialek topological distribution factors applied to transmission network with 7 buses managed by a TSO. The last case study presents a joint market model simulation which considers the aggregation of small players to a VPP, as well as complex contracts related to these entities. The case study comprises a distribution network with 33 buses managed by VPP, which comprises several kinds of distributed resources, such as photovoltaic, CHP, fuel cells, wind turbines, biomass, small hydro, municipal solid waste, demand response, and storage units.
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For uniformly asymptotically affine (uaa) Markov maps on train tracks, we prove the following type of rigidity result: if a topological conjugacy between them is (uaa) at a point in the train track then the conjugacy is (uaa) everywhere. In particular, our methods apply to the case in which the domains of the Markov maps are Canter sets. We also present similar statements for (uaa:) and C-r Markov families. These results generalize the similar ones of Sullivan and de Faria for C-r expanding circle maps with r > 1 and have useful applications to hyperbolic dynamics on surfaces and laminations.
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For diffeomorphisms on surfaces with basic sets, we show the following type of rigidity result: if a topological conjugacy between them is differentiable at a point in the basic set then the conjugacy has a smooth extension to the surface. These results generalize the similar ones of D. Sullivan, E. de Faria and ours for one-dimensional expanding dynamics.
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The high penetration of distributed energy resources (DER) in distribution networks and the competitive environment of electricity markets impose the use of new approaches in several domains. The network cost allocation, traditionally used in transmission networks, should be adapted and used in the distribution networks considering the specifications of the connected resources. The main goal is to develop a fairer methodology trying to distribute the distribution network use costs to all players which are using the network in each period. In this paper, a model considering different type of costs (fixed, losses, and congestion costs) is proposed comprising the use of a large set of DER, namely distributed generation (DG), demand response (DR) of direct load control type, energy storage systems (ESS), and electric vehicles with capability of discharging energy to the network, which is known as vehicle-to-grid (V2G). The proposed model includes three distinct phases of operation. The first phase of the model consists in an economic dispatch based on an AC optimal power flow (AC-OPF); in the second phase Kirschen's and Bialek's tracing algorithms are used and compared to evaluate the impact of each resource in the network. Finally, the MW-mile method is used in the third phase of the proposed model. A distribution network of 33 buses with large penetration of DER is used to illustrate the application of the proposed model.
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Temporomandibular disorders (TMD) consist of a group of pathologies that affect the masticatory muscles, temporomandibular joints (TMJ), and/or related structures. String instrumentalists, like many orchestra musicians, can spend hours with head postures that may influence the biomechanical behavior of the TMJ and the muscles of the craniocervicomandibular complex (CCMC). The adoption of abnormal postures acquired during performance by musicians can lead to muscular hyperactivity of the head and cervical muscles, with the possible appearance of TMD. Medical infrared thermography is a non-invasive procedure that can monitor the changes in the superficial tissue related to blood circulation and may serve as a complement to the clinical examination. The objective of this study was to use infrared thermography to evaluate, in one subject, the cutaneous thermal changes adjacent to the CCMC that occur before, during, and after playing a string instrument.
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RESUMO - O problema do erro de medicação tem vindo a adquirir uma importância e um interesse crescentes nos últimos anos. As consequências directas no doente que condicionam frequentemente o prolongamento do internamento, a necessidade de utilização adicional de recursos e a diminuição de satisfação por parte dos doentes, são alguns dos aspectos que importa analisar no sentido de se aumentar a segurança do doente. No circuito do medicamento em meio hospitalar estão envolvidos diversos profissionais, estando o enfermeiro no final da cadeia quando administra a medicação ao doente. Na bibliografia internacional, são referidas incidências elevadas de eventos adversos relacionados com o medicamento. Em Portugal, não existem estudos disponíveis que nos permitam conhecer, nem o tipo de incidentes, nem a dimensão do problema do erro de medicação. Efectuamos um estudo descritivo, prospectivo, exploratório, utilizando a técnica de observação não participante, da administração de medicamentos. Os objectivos são, por um lado, determinar a frequência de incidentes na administração de medicação num Serviço de Medicina Interna e, por outro, caracterizar o tipo de incidentes na administração da medicação e identificar as suas possíveis causas. A população em estudo foi constituída pelos enfermeiros que administraram medicamentos aos doentes internados no Serviço de Medicina Interna seleccionado, durante os meses de junho a agosto de 2012, sendo observadas 1521 administrações. Foi utilizada uma grelha de observação, que incluiu os seguintes elementos: doente certo; medicamento certo; dose certa; hora certa; via certa; técnica de administração correcta (assépsia); tempo de infusão; monitorização correcta. Constatou-se que em 43% das doses administradas apresentavam pelo menos um erro, num total de 764 erros. Não foi observado nenhum erro de doente, de medicamento, de dose extra, de via, de forma farmacêutica, nem a administração de medicamento não prescrito. Detectaram-se 0,19% de erros na preparação, 0,72% de erros de dose, 1,7% erros de omissão, 1,97% de erros de administração, 13,52% de erros de monitorização, 28,73% de erros de v horário. O tempo de infusão da terapêutica parentérica não foi cumprida em 27,69% das oportunidades, tendo sido sempre administrado em tempo inferior ao preconizado. Não encontramos relação entre as interrupções durante a administração de terapêutica e os erros. Pelo contrário constatou-se haver relação entre o número de doses com erro e o turno em que ocorreram, sendo mais frequentes no turno da noite. Constatamos também que aos fins de semana os erros eram mais frequentes e o risco da ocorrência de um erro na administração de medicação aumenta 1,5 vezes quando o número de enfermeiros é insuficiente.
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The wound healing response is an essential mechanism to maintain the integrity of epithelia and protect all organisms from the surrounding milieu. In the “purse-string” mechanism of wound closure, an injured epithelial sheet cinches its hole closed via an intercellular contractile actomyosin cable.(...)
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The case of a patient with blue rubber bleb nevus syndrome who is infected by acquired immunodeficiency syndrome virus due to multiple blood transfusions is presented. This case shows that although it is a rare systemic disorder, blue rubber bleb nevus syndrome has to be considered in the differential diagnosis of chronic anemia or gastrointestinal bleeding. Patients should be investigated by endoscopy, which is the most reliable method for detecting these lesions. The patient underwent gastroscopy and enteroscopy via enterotomy with identification of all lesions. Minimal resection of the larger lesions and string-purse suture of the smaller ones involving all the layers of the intestine were performed. The string-purse suture of the lesions detected by enteroscopy proved to be an effective technique for handling these lesions, avoiding extensive intestinal resection and stopping the bleeding. Effective management of these patients demands aggressive treatment and should be initiated as soon as possible to avoid risks involved in blood transfusions, as occurred in this case.
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A presente investigação debruça-se sobre o estudo dos grandes conjuntos urbanos, tendo como referência a área de Lisboa no período entre 1945 e 1974. O seu objetivo principal é compreender o padrão espacial e respetivas variantes destas formas urbanas relativamente recentes bem como avaliar o seu impato na estrutura global da cidade e da sociedade. Tomando como ponto de partida a história de arte como história da cidade, a tese toma como objeto o grande conjunto urbano e aponta a hipótese do estudo da relação forma-fundo como meio de obter informações relevantes que relacionem o uso e função com respeito ao desenho do espaço aberto. Como diferentes arranjos entre espaços abertos e fechados implicam tipos espaciais distintos (Medeiros 2013), o estudo da relação entre a forma (cheio) e o fundo (vazio) dos grandes conjuntos urbanos e respetivas variações, pode fornecer-nos informação espacial relevante, que nos permitem compreender melhor estas formas urbanas recentes. Usando a abordagem própria da teoria da sintaxe espacial (Hillier e Hanson 1984), do tipo configuracional, determinam-se as relações entre os vários elementos constituintes dos sistemas espaciais formados nestas urbanizações. Essas relações são depois analisadas através de medidas e variáveis topológicas que nos permitem identificar qualidades e valores espaciais para a sociedade. Os resultados obtidos a partir dessas variáveis e medidas permitem-nos, depois, avaliar os graus de ‘formalidade’ e ‘urbanidade’ em cada sistema (Holanda 2002). Consequentemente, a avaliação qualitativa das características espaciais que se pretendem obter nesta investigação, tem como base a avaliação quantitativa, permitindo assim comparar mais facilmente os diversos casos de estudo. De entre o conjunto de casos analisados, o estudo revela uma série de características comuns, que nos permitem identificar um padrão específico de urbanismo modernista que reflete claramente um conjunto de ideologias associadas a uma visão reformista da sociedade através do espaço. Mas por outro lado, existem também um conjunto de características particulares de cada caso, que reportam para a estrutura morfológica da cidade tradicional. No que reporta à hipótese de estudo levantada nesta investigação sobre a relação forma-fundo, verifica-se através da amostra que esta relação aparece invertida. Esta diferenciação deve-se ao abandono dos tradicionais sistemas de rua e de quarteirão, ainda presentes nas urbanizações de Alvalade e do Areeiro e a sua substituição pelo bloco livre em espaço aberto como nos casos de Alfragide, Portela e Olivais. Tal facto, como prova a teoria da Sintaxe Espacial ou Lógica Social do Espaço, traduziu-se necessariamente em diferentes modos de vida pública e privada e consequentemente de vida espacial e social. Assim concluímos, através da análise dos casos de estudo apresentados, que embora fazendo parte duma mesma ideologia urbana com características comuns (genótipo modernista), os mesmos apresentam resultados espaciais totalmente diferenciados o que justifica a dificuldade da sua análise comparativa.
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The jet energy scale (JES) and its systematic uncertainty are determined for jets measured with the ATLAS detector using proton–proton collision data with a centre-of-mass energy of s√=7 TeV corresponding to an integrated luminosity of 4.7 fb −1 . Jets are reconstructed from energy deposits forming topological clusters of calorimeter cells using the anti- kt algorithm with distance parameters R=0.4 or R=0.6 , and are calibrated using MC simulations. A residual JES correction is applied to account for differences between data and MC simulations. This correction and its systematic uncertainty are estimated using a combination of in situ techniques exploiting the transverse momentum balance between a jet and a reference object such as a photon or a Z boson, for 20≤pjetT<1000 GeV and pseudorapidities |η|<4.5 . The effect of multiple proton–proton interactions is corrected for, and an uncertainty is evaluated using in situ techniques. The smallest JES uncertainty of less than 1 % is found in the central calorimeter region ( |η|<1.2 ) for jets with 55≤pjetT<500 GeV . For central jets at lower pT , the uncertainty is about 3 %. A consistent JES estimate is found using measurements of the calorimeter response of single hadrons in proton–proton collisions and test-beam data, which also provide the estimate for pjetT>1 TeV. The calibration of forward jets is derived from dijet pT balance measurements. The resulting uncertainty reaches its largest value of 6 % for low- pT jets at |η|=4.5 . Additional JES uncertainties due to specific event topologies, such as close-by jets or selections of event samples with an enhanced content of jets originating from light quarks or gluons, are also discussed. The magnitude of these uncertainties depends on the event sample used in a given physics analysis, but typically amounts to 0.5–3 %.
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Results of a search for decays of massive particles to fully hadronic final states are presented. This search uses 20.3 fb−1 of data collected by the ATLAS detector in s√=8TeV proton--proton collisions at the LHC. Signatures based on high jet multiplicities without requirements on the missing transverse momentum are used to search for R-parity-violating supersymmetric gluino pair production with subsequent decays to quarks. The analysis is performed using a requirement on the number of jets, in combination with separate requirements on the number of b-tagged jets, as well as a topological observable formed from the scalar sum of the mass values of large-radius jets in the event. Results are interpreted in the context of all possible branching ratios of direct gluino decays to various quark flavors. No significant deviation is observed from the expected Standard Model backgrounds estimated using jet-counting as well as data-driven templates of the total-jet-mass spectra. Gluino pair decays to ten or more quarks via intermediate neutralinos are excluded for a gluino with mass mg~<1TeV for a neutralino mass mχ~01=500GeV. Direct gluino decays to six quarks are excluded for mg~<917GeV for light-flavor final states, and results for various flavor hypotheses are presented.
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We search for evidence of physics beyond the Standard Model in the production of final states with multiple high transverse momentum jets, using 20.3 fb−1 of proton-proton collision data recorded by the ATLAS detector at s√ = 8 TeV. No excess of events beyond Standard Model expectations is observed, and upper limits on the visible cross-section for non-Standard Model production of multi-jet final states are set. Using a wide variety of models for black hole and string ball production and decay, the limit on the cross-section times acceptance is as low as 0.16 fb at the 95% CL for a minimum scalar sum of jet transverse momentum in the event of about 4.3 TeV. Using models for black hole and string ball production and decay, exclusion contours are determined as a function of the production mass threshold and the gravity scale. These limits can be interpreted in terms of lower-mass limits on black hole and string ball production that range from 4.6 to 6.2 TeV.
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The artificial fish swarm algorithm has recently been emerged in continuous global optimization. It uses points of a population in space to identify the position of fish in the school. Many real-world optimization problems are described by 0-1 multidimensional knapsack problems that are NP-hard. In the last decades several exact as well as heuristic methods have been proposed for solving these problems. In this paper, a new simpli ed binary version of the artificial fish swarm algorithm is presented, where a point/ fish is represented by a binary string of 0/1 bits. Trial points are created by using crossover and mutation in the different fi sh behavior that are randomly selected by using two user de ned probability values. In order to make the points feasible the presented algorithm uses a random heuristic drop item procedure followed by an add item procedure aiming to increase the profit throughout the adding of more items in the knapsack. A cyclic reinitialization of 50% of the population, and a simple local search that allows the progress of a small percentage of points towards optimality and after that refines the best point in the population greatly improve the quality of the solutions. The presented method is tested on a set of benchmark instances and a comparison with other methods available in literature is shown. The comparison shows that the proposed method can be an alternative method for solving these problems.