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Um modelo para condutores múltiplos considerando a distribuição da corrente nos subcondutoresCosta, Eduardo Coelho Marques da [UNESP] 27 July 2009 (has links) (PDF)
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costa_ecm_me_ilha.pdf: 1777300 bytes, checksum: f5e35375b4a1e9e034ae9b487436cef5 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O presente trabalho descreve detalhadamente uma metodologia alternativa para o cálculo dos parâmetros longitudinais e transversais de um condutor múltiplo genérico, com base na configuração de um condutor equivalente. A metodologia proposta considera precisamente o acoplamento mútuo entre os subcondutores que compões o feixe, a natureza distribuída dos parâmetros e a distribuição da corrente, uniforme ou desigual, através dos subcondutores. São calculados e analisados os parâmetros utilizando a metodologia alternativa proposta e o procedimento clássico baseado na obtenção de um condutor equivalente aplicando o conceito do Raio Médio Geométrico (RMG), para diversos condutores múltiplos, sendo eles simétricos ou não simétricos, convencionais ou não-convencionais. Posteriormente, são comparados os resultados obtidos por ambos os métodos e a partir desses é possível comprovar a eficácia da metodologia proposta e eventuais situações em que a metodologia clássica, envolvendo o conceito do RMG, apresenta algumas imprecisões derivadas da distribuição não uniforme da corrente em condutores múltiplos assimétricos ou pouco convencionais / The present work describes an alternative methodology to evaluate the longitudinal and transversal parameters of a generic bundled conductor, based on the configuration of an equivalent conductor. The proposed methodology considers precisely the mutual coupling among subconductors of the bundle, the distributed nature of parameters and the current distribution through subconductors. The parameters are calculated and analyzed using the proposed alternative methodology and the classic procedure, based on equivalent conductor applying the concept of Geometric Mean Radius (GMR), for several bundled conductors, symmetric or nonsymmetric, conventional or non-conventional. Subsequently, the obtained results are compared to both methods and then it is possible to verify the efficacy of the proposed methodology and eventual situations where the classic methodology, based on RMG concept, presents inaccuracies due to the non-uniform distribution of the current in non-symmetric or non-conventional bundled conductors
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Simulace dějů predikovaných teorií zamrzlé plasticity / Simulation of processes predicted by theory of frozen plasticityNekola, Ondřej January 2017 (has links)
The question of the tempo of evolution is amongst the oldest conundrums in evolutionary biology and has not been satisfactorily answered yet. One of the attempts to do so is the frozen plasticity theory, which postulates that a sexually reproducing species is only capable of evolution within short periods of time after its genetic polymorphism decreases e.g. as a consequence of peripatric speciation. In the longer periods of evolutionary stasis, its evolution is limited by frequency- dependent selection and pleiotropy. In this work, I have produced an open source software simulating the respon- ses of populations of sexually reproducing individuals to varying environmental conditions. Using this software, I simulated evolution of populations with different probabilities of arising of alelles affecting more phenotypic traits and frequency- dependent selected alleles that have opposing phenotypic effects when present at the locus in one copy, respectively two copies. I observed trends predicted by the theory of frozen plasticity: slower adap- tation to instant environmental changes, lower achieved fitness and more frequent extinctions of populations with higher portions of investigated types of alleles, but only with low effect sizes and without statistical significance. For future research, it would be desirable...
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Towards Measuring the Maxwell–Boltzmann Distribution of a Single Heated ParticleSu, Xiaoya, Fischer, Alexander, Cichos, Frank 30 March 2023 (has links)
The Maxwell–Boltzmann distribution is a hallmark of statistical physics in thermodynamic
equilibrium linking the probability density of a particle’s kinetic energies to the temperature
of the system that also determines its configurational fluctuations. This unique relation is
lost for Hot Brownian Motion, e.g., when the Brownian particle is constantly heated to
create an inhomogeneous temperature in the surrounding liquid. While the fluctuations of
the particle in this case can be described with an effective temperature, it is not unique for
all degrees of freedom and suggested to be different at different timescales. In this work,
we report on our progress to measure the effective temperature of Hot Brownian Motion in
the ballistic regime. We have constructed an optical setup to measure the displacement of
a heated Brownian particle with a temporal resolution of 10 ns giving a corresponding
spatial resolution of about 23 pm for a 0.92 μm PMMA particle in water. Using a goldcoated
polystyrene (AuPS) particle of 2.15 μm diameter we determine the mean squared
displacement of the particle over more than six orders of magnitude in time. Our data
recovers the trends for the effective temperature at long timescales, yet shows also clear
effects in the region of hydrodynamic long time tails.
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Um modelo para condutores múltiplos considerando a distribuição da corrente nos subcondutores /Costa, Eduardo Coelho Marques da. January 2009 (has links)
Orientador: Sérgio Kurokawa / Banca: Afonso José do Prado / Banca: Lourenço Matias / Resumo: O presente trabalho descreve detalhadamente uma metodologia alternativa para o cálculo dos parâmetros longitudinais e transversais de um condutor múltiplo genérico, com base na configuração de um condutor equivalente. A metodologia proposta considera precisamente o acoplamento mútuo entre os subcondutores que compões o feixe, a natureza distribuída dos parâmetros e a distribuição da corrente, uniforme ou desigual, através dos subcondutores. São calculados e analisados os parâmetros utilizando a metodologia alternativa proposta e o procedimento clássico baseado na obtenção de um condutor equivalente aplicando o conceito do Raio Médio Geométrico (RMG), para diversos condutores múltiplos, sendo eles simétricos ou não simétricos, convencionais ou não-convencionais. Posteriormente, são comparados os resultados obtidos por ambos os métodos e a partir desses é possível comprovar a eficácia da metodologia proposta e eventuais situações em que a metodologia clássica, envolvendo o conceito do RMG, apresenta algumas imprecisões derivadas da distribuição não uniforme da corrente em condutores múltiplos assimétricos ou pouco convencionais / Abstract: The present work describes an alternative methodology to evaluate the longitudinal and transversal parameters of a generic bundled conductor, based on the configuration of an equivalent conductor. The proposed methodology considers precisely the mutual coupling among subconductors of the bundle, the distributed nature of parameters and the current distribution through subconductors. The parameters are calculated and analyzed using the proposed alternative methodology and the classic procedure, based on equivalent conductor applying the concept of Geometric Mean Radius (GMR), for several bundled conductors, symmetric or nonsymmetric, conventional or non-conventional. Subsequently, the obtained results are compared to both methods and then it is possible to verify the efficacy of the proposed methodology and eventual situations where the classic methodology, based on RMG concept, presents inaccuracies due to the non-uniform distribution of the current in non-symmetric or non-conventional bundled conductors / Mestre
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Optical and noise studies for Advanced Virgo and filter cavities for quantum noise reduction in gravitational-wave interferometric detectors / Études optiques et de bruit pour Advanced Virgo et cavités de filtrage pour la réduction du bruit quantique dans les détecteurs interférométriques d’ondes gravitationnellesCapocasa, Eleonora 13 November 2017 (has links)
L'astronomie gravitationnelle a débuté en septembre 2015 avec la première détection de la fusion de deux trous noirs par LIGO. Depuis lors, plusieurs fusions de trous noirs et une fusion d'étoiles à neutrons ont été observées. Advanced Virgo a rejoint les deux observatoires LIGO dans la prise de données en août 2017, augmentant fortement les capacités de localisation du réseau. Afin d'exploiter pleinement le potentiel scientifique de ce nouveau domaine, un énorme effort expérimental est nécessaire pour améliorer la sensibilité des interféromètres. Cette thèse, développée dans ce contexte, est composée de deux parties. La première concerne Advanced Virgo : nous avons développé un budget de bruit automatique pour le bruit de fréquence du laser et nous avons effectué des mesures de caractérisation optique pour les cavités de bras kilométriques. Des pertes aller-retour aussi faibles que 80 ppm ont été mesurées. Elles sont parmi les plus basses jamais mesurées avec un faisceau de cette taille. La deuxième partie concerne la conception et le développement d'une cavité de filtrage de 300 m, un prototype pour démontrer la production de lumière squeezing dépendante de la fréquence avec les propriétés nécessaires pour une réduction du bruit quantique à large bande dans KAGRA, Advanced Virgo et Advanced LIGO. Nous avons contribué à la fois aux phases de conception et d'intégration du projet. Nous avons d'abord fait le design optique de la cavité, y compris les spécifications pour l'optique de la cavité et une estimation détaillée des sources de dégradation pour le squeezing. Nous avons donc développé un système de contrôle pour les miroirs, assemblé les suspensions et finalement aligné et mis la cavité en résonance avec la lumière laser / Gravitational wave astronomy has started in September 2015 with the first detection of a binary black-hole merger by LIGO. Since then, several black-hole mergers and a binary neutron star merger have been observed. Advanced Virgo joined the two LIGO detector in the observation run, in August 2017, highly increasing the localization capabilities of the network. In order to fully exploit the scientific potential of this new-born field, a huge experimental effort is needed to bring the instruments at their design sensitivity and to further improve them. This thesis, developed in this context, it is composed of two parts. The first is about Advanced Virgo: we have developed an automatic noise budget for the laser frequency noise and we have performed optical characterization measurements for the kilometric arm cavities. Round trip Losses as low as 80 ppm have been measured. They are among the lowest ever measured for beams of these size. The second part is about the design and development of a 300 m filter cavity, a prototype to demonstrate the frequency dependent squeezing production with properties needed for a broadband quantum noise reduction in the future upgrades of KAGRA, Advanced Virgo and Advanced LIGO. We have contributed to the design and integration phases of the project. We have first made the optical design of the cavity, including the the specifications for the main cavity optics and a detailed estimation of the squeezing degradation sources. We have then developed a local control system for the mirrors, assembled the suspensions, and finally aligned and brought the cavity in resonance with the laser light
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The extraordinary sex ratios in the splash pool copepod Tigriopus californicusTai, Travis Christopher 27 August 2014 (has links)
Fisher’s adaptive sex ratio theory predicts that organisms should invest equally in sons and daughters and the sex ratio at conception should be 1:1. Hamilton’s theory predicts that organisms should adjust sex ratios based on the relative strength of competition within a mating group. Testing sex ratio and sex allocation theories requires variation in sex ratio. Different sex allocation and sex allocation adjustment mechanisms can produce skewed sex ratios. I used Tigriopus californicus, a harpacticoid copepod with extrabinomial variation in sex ratios, to test sex ratio evolution and socially-mediated sex determination. Using artificially selected sex-biased populations, the trajectory of population sex ratios were as expected under Fisher’s theory and sex ratios approached/reached 0.5 proportion males. Populations with overlapping generations had a slower rate of change towards 0.5 than populations with non-overlapping generations. I show that these data are supported by multiple different models: a mechanistic and simulation model. I tested socially-mediated sex determination using seawater conditioned with different local sex ratios of copepods. There were detectable effects found in both wild populations and isofemale lines. However, these effects may be trivial as differences were small between treatments. Sex determination in T. californicus is a complex mechanism, with multiple genetic and environmental components. The complex nature of sex determination in T. californicus and the dynamic nature of their habitat in highly ephemeral splash pools provide a possible explanation for the non-Fisherian sex ratios we see. / Graduate
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An Improved Wide-Band System Equivalent Technique for Real Time Digital SimulatorsLiang, Yuefeng 07 April 2011 (has links)
This thesis introduces a new modeling approach that allows very large power systems to be modeled on a real time electro-magnetic transients (EMT) digital simulator with reduced hardware costs. The key step in achieving this is the development of an improved wide-band multi-port equivalent, which reduces a large power network into a small manageable equivalent model that preserves wideband behaviors.
This approach has a foundation method that use a two part equivalent in which the high frequency behavior of the equivalenced network is represented by a terminating frequency dependent network equivalent (FDNE), with the low frequency behavior being modeled using a detailed Transient Stability Analysis (TSA) model that only models the electromechanical behavior. This approach allowed the modelling of medium size electric regions up to hundreds of buses in real time.
This thesis extends the equivalent by implementing a reduced order of the detailed electromechanical TSA equivalent mentioned above. Coherency based reduction is used for the electromechanical model of the power network to be equivalenced, and is implemented as a Transient Stability Analysis (TSA) type electromechanical equivalent. A challenge in implementing the FDNE is to ensure that it is a passive network, as otherwise its inclusion could lead to unstable simulation. This thesis also introduces a practical procedure to enforce passivity in the FDNE.
The validity of the proposed technique is demonstrated by comparing the approach with detailed electromagnetic simulations of the well-known 39 bus New England system and a modified 39 bus system with an HVDC infeed with coupling between the dc line and an adjacent ac line, in addition to a 108 bus ac system. The power of the method is demonstrated by the real-time simulation of a large system with 2300 busses and 139 generators. It has been shown that this approach has the potential to increase by at least one order of magnitude the size of the network that can be modeled and thus on a real time electro-magnetic transients (EMT) digital simulator with reduced hardware costs.
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An Improved Wide-Band System Equivalent Technique for Real Time Digital SimulatorsLiang, Yuefeng 07 April 2011 (has links)
This thesis introduces a new modeling approach that allows very large power systems to be modeled on a real time electro-magnetic transients (EMT) digital simulator with reduced hardware costs. The key step in achieving this is the development of an improved wide-band multi-port equivalent, which reduces a large power network into a small manageable equivalent model that preserves wideband behaviors.
This approach has a foundation method that use a two part equivalent in which the high frequency behavior of the equivalenced network is represented by a terminating frequency dependent network equivalent (FDNE), with the low frequency behavior being modeled using a detailed Transient Stability Analysis (TSA) model that only models the electromechanical behavior. This approach allowed the modelling of medium size electric regions up to hundreds of buses in real time.
This thesis extends the equivalent by implementing a reduced order of the detailed electromechanical TSA equivalent mentioned above. Coherency based reduction is used for the electromechanical model of the power network to be equivalenced, and is implemented as a Transient Stability Analysis (TSA) type electromechanical equivalent. A challenge in implementing the FDNE is to ensure that it is a passive network, as otherwise its inclusion could lead to unstable simulation. This thesis also introduces a practical procedure to enforce passivity in the FDNE.
The validity of the proposed technique is demonstrated by comparing the approach with detailed electromagnetic simulations of the well-known 39 bus New England system and a modified 39 bus system with an HVDC infeed with coupling between the dc line and an adjacent ac line, in addition to a 108 bus ac system. The power of the method is demonstrated by the real-time simulation of a large system with 2300 busses and 139 generators. It has been shown that this approach has the potential to increase by at least one order of magnitude the size of the network that can be modeled and thus on a real time electro-magnetic transients (EMT) digital simulator with reduced hardware costs.
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[en] VOLTAGE STABILITY ASSESSMENT CONSIDERING PRIMARY FREQUENCY CONTROL AND FREQUENCY-DEPENDENT LINE PARAMETERS / [pt] AVALIAÇÃO DAS CONDIÇÕES DE ESTABILIDADE DE TENSÃO CONSIDERANDO A REGULAÇÃO PRIMÁRIA E PARÂMETROS DA REDE VARIÁVEIS COM A FREQUÊNCIADIANA MARGARITA GARCIA MARTINEZ 05 January 2016 (has links)
[pt] A crescente demanda de energia elétrica faz com que a complexidade dos
sistemas elétricos de potência seja cada vez maior, associado às limitações na
expansão do sistema de transmissão, resulta na operação dos sistemas elétricos
mais próximos de seus limites, tornando-os vulneráveis a problemas de
estabilidade de tensão. Nesse contexto, faz-se necessário o desenvolvimento de
ferramentas computacionais capazes de representar os sistemas elétricos mais
adequadamente, melhorando assim as condições de análise. Neste trabalho são
apresentadas três modelagens do fluxo de carga mais completas que a modelagem
clássica, a saber: a modelagem de múltiplas barras swing, a modelagem com
regulação primária e a modelagem com parâmetros da rede de transmissão
variáveis com a frequência. Uma vez utilizadas na solução do problema do fluxo
de carga estas modelagens são estendidas para a realização do cálculo dos índices
de estabilidade de tensão das barras de carga, barras de tensão controlada e barras
swing. Testes numéricos com um sistema-teste de 6 barras são apresentados para a
verificação da aplicabilidade e adequação dos modelos analisados. / [en] The growing demand for electricity increases the complexity of electric
power systems which, when combined with limitations in the expansion of
transmission systems, results in the operation of electrical systems closer to their
limits, making them vulnerable to voltage stability problems. In this context, there
is a gap in the market for the development of computational tools that can
represent the electrical systems more appropriately, thereby improving the
conditions of analysis. The present study formulates three non-classical load flow
representations: multiple swing buses, primary frequency control, and frequency
dependent transmission network parameters. Once used in the load flow problem
solving, these models are also extended to allow the calculation of voltage
stability indices of load buses, controlled voltage buses and swing buses.
Numerical tests with a 6-bus test system are presented to verify the applicability
and adequacy of the proposed models.
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Inclusão do efeito corona em modelos de linhas de transmissão bifásica utilizando a técnica de variáveis de estadoWedy, Germano Ferreira [UNESP] 27 July 2009 (has links) (PDF)
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wedy_gf_me_ilha.pdf: 790523 bytes, checksum: 8836dfe828e124530d6a988987704e3f (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O objetivo deste projeto é o desenvolvimento de um modelo de linha de transmissão bifásica diretamente no domínio do tempo, que leve em consideração o efeito corona e o efeito da freqüência sobre seus parâmetros longitudinais, utilizando os conceitos de variáveis de estado. Os parâmetros longitudinais de uma linha de transmissão dependentes da freqüência serão sintetizados por meio de funções racionais pelo método do Vector Fitting. Em seguida, as funções racionais que descrevem o comportamento dos parâmetros longitudinais serão associadas com um circuito elétrico equivalente, que será inserido em cada um dos circuitos . Para a validação do modelo desenvolvido levando em consideração o efeito da freqüência o mesmo foi comparado com o programa de estudo de transitórios eletromagnético Micotran do tipo EMTP. Utilizando o modelo matemático desenvolvido foi possível inserir através das equações de Gary e de Skilling-Umoto, o efeito corona nas simulações de transitórios eletromagnético. Ao termino do projeto, apresenta-se um modelo matemático de uma linha de transmissão que leva em conta o efeito da freqüência e o efeito corona. Tal modelo não necessita dos programas do tipo EMTP para simulação de transitórios em linhas de transmissão. / The objective of this work is to implement a computational model of two-phase transmission line directly in the time domain, which takes into account the corona effect and the effect of frequency on its longitudinal parameters, using the concepts of state variables. The longitudinal parameters of a frequency dependent transmission line are synthesized by rational functions using the Vector Fitting method. Then, the rational functions that describe the behavior of the longitudinal parameters will be associated with an equivalent electrical circuit, which is inserted in very circuit . Validating the model developed taking into account the effect of frequency, this model was compared to the Micotran program, a EMTP (Electromagnetic Transient Program) type program that is used for transient analyses in electrical networks. Through the developed mathematical model, it enter, through the equations of Gary and Skilling-Umoto, the corona effect in simulations of electromagnetic transients. At the end of the project, it is obtained a mathematical model of a transmission line that takes into account the effect of frequency and the corona effect. This model does not need the EMTP type programs for transient simulations in transmission lines.
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