Método híbrido para o cálculo dos custos de interrupções em processos eletro-eletrônicos causados por faltas em sistemas de distribuição de energia elétrica

Neste trabalho é apresentado um método híbrido para análise de riscos de interrupções em processos sensíveis provocadas por faltas nos sistemas de distribuição de energia elétrica. Com a utilização deste método, são avaliados índices relativos às interrupções de longa duração e às variações de tensão de curta duração (afundamentos e elevações) em cada consumidor da rede de distribuição de energia elétrica. O método permite, de forma inovadora, a obtenção, para cada ocorrência na rede, dos valores de magnitude da tensão e da duração do evento. Em cada barra do sistema, as freqüências de ocorrências de cada índice são obtidas e classificadas por faixas de magnitude e duração. O método parte de um conjunto de informações de configuração, de parâmetros da rede e dos dispositivos de proteção e, através de um conjunto de simulações aleatórias de curto-circuito, é possível mapear as áreas de risco relativas aos fenômenos de interrupção e variações de tensão de curta duração (VTCDs). Dispondo ainda do conjunto de curvas de sensibilidade dos processos industriais, avaliam-se as freqüências de disrupções de processos, esperadas por ano no ponto analisado, isto é, o número de vezes que um processo é interrompido pelos eventos de curta duração considerados, para então serem avaliados os custos anuais associados.This paper shows a new hybrid method for risk assessment regarding interruptions in sensitive processes due to faults in electric power distribution systems. This method determines indices related to long duration interruptions and short duration voltage variations, such as voltage sags and swells in each customer supplied by the distribution network. Frequency of such occurrences and their impact on customer processes are determined for each bus and classified according to their corresponding magnitude and duration. The method bases on information regarding network configuration, system parameters and protective devices and randomly generates a number of fault scenarios to assess risk areas regarding long duration interruptions and voltage sags and swells. Based on process sensitivity curves, the method determines frequency indices regarding disruption in customer processes that represent possible process interruptions due to the considered short duration events to eventually determine the associated annual costs

Allocation of power quality meters by genetic algorithms and Fuzzy sets theory

Neste artigo é apresentada a aplicação de Algoritmos Genéticos (AGs) e Conjuntos Fuzzy no dimensionamento de sistemas para a monitoração de Variações de Tensão de Curta Duração (VTCDs) em redes de transmissão de energia elétrica. De acordo com a metodologia proposta, são simulados diferentes tipos de curto-circuitos em diversos pontos, com o intuito de caracterizar o Sistema Elétrico de Potência (SEP) em avaliação com relação a ocorrência de VTCDs. Em seguida, diferentes configurações para o sistema de monitoração, isto é, número de medidores e barras em que os mesmos devam ser instalados, são avaliadas através de AGs, com o objetivo de garantir que ao menos um dos medidores seja sensibilizado para cada um dos curto-circuitos simulados. Duas formas de modelagem do AG são apresentadas, sendo uma utilizando vetores binários para a decisão da instalação de medidores nas barras do SEP e a outra utilizando vetores inteiros, para a indicação das barras do SEP em que devem ser instalados os medidores. É feita a comparação das duas modelagens, bem como a avaliação dos resultados fornecidos pela medologia para uma rede de transmissão real de 154 barras. A metodologia também é aplicada na rede teste de 30 barras do IEEE, de modo a permitir a comparação da mesma com trabalhos semelhantes na área.The aim of this article is to present the application of Genetic Algorithms (GAs) and Fuzzy Mathematical Programming in the design of voltage sag and swell monitoring systems for power transmission networks. The proposed methodology uses the simulation of different types of short-circuit in many different points of the power system, in order to characterize the system behavior towards the occurrence of voltage sags and swells. Then, different configurations for the monitoring system, i.e. number of monitors and buses where they are supposed to be installed, are assessed through GAs. Two different GA codifications are presented, namely one based on binary vectors, for the decision over the installation of a monitor in a specific bus of the power system and another based on integer vectors, in order to indicate in which buses the monitors should be installed. A comparison between the two models is presented. The evaluation of the methodology performance is determined for a real 154 bus transmission network. The methodology is also applied for the IEEE 30 bus network, in order to allow its comparison with a previous research work

Multi-objective robust optimization to solve energy scheduling in buildings under uncertainty

With the high penetration of renewable generation in Smart Grids (SG), the uncertainty behavior associated with the forecast of weather conditions possesses a new degree of complexity in the Energy Resource Management (ERM) problem. In this paper, a Multi-Objective Particle Swarm Optimization (MOPSO) methodology is proposed to solve ERM problem in buildings with penetration of Distributed Generation (DG) and Electric Vehicles (EVs) and considering the uncertainty of photovoltaic (PV) generation. The proposed methodology aims to maximize profits while minimizing CO 2 emissions. The uncertainty of PV generation is modeled with the use of Monte Carlo simulation in the evaluation process of the MOPSO core. Also, a robust optimization approach is adopted to select the best solution for the worst-case scenario of PV generation. A case study is presented using a real building facility from Brazil, to verify the effectiveness of the implemented robust MOPSO.This work has received funding from the Project NetEffiCity (ANI|P2020 18015), and from FEDER Funds through COMPETE program and from National Funds through FCT under the project UID/EEA/00760/2013.info:eu-repo/semantics/publishedVersio

Prognostic implications of carboxyl-terminus of Hsc70 interacting protein and lysyl-oxidase expression in human breast cancer

This article has been made available through the Brunel Open Access Publishing Fund - Copyright @ 2010 Patani.Background: Ubiquitin modification of proteins influences cellular processes relevant to carcinogenesis. CHIP (carboxyl-terminus of Hsc70-interacting protein) is a chaperone-dependent E3 ubiquitin ligase, regulating the stability of heat shock protein 90 (HSP90) interacting proteins. CHIP is implicated in the modulation of estrogen receptor (ESR1) and Her-2/neu (ERBB2) stability. LOX (lysyl-oxidase) serves intracellular roles and catalyses the cross-linking of extracellular matrix (ECM) collagens and elastin. LOX expression is altered in human malignancies and their peri-tumoral stroma. However, paradoxical roles are reported. In this study, the level of mRNA expression of CHIP and LOX were assessed in normal and malignant breast tissue and correlated with clinico-pathological parameters. Materials and Methods: Breast cancer (BC) tissues (n = 127) and normal tissues (n = 33) underwent RNA extraction and reverse transcription; transcript levels were determined using real-time quantitative PCR and normalized against CK-19. Transcript levels were analyzed against TNM stage, nodal involvement, tumor grade and clinical outcome over a ten-year follow-up period. Results: CHIP expression decreased with increasing Nottingham Prognostic Index (NPI): NPI-1 vs. NPI-3 (12.2 vs. 0.2, P = 0.0264), NPI-2 vs. NPI-3 (3 vs. 0.2, P = 0.0275). CHIP expression decreased with increasing TNM stage: TNM-1 vs. TNM-2 (12 vs. 0, P = 0.0639), TNM-1 vs. TNM-2-4 (12 vs. 0, P = 0.0434). Lower transcript levels were associated with increasing tumor grade: grade 1 vs. grade 3 (17.7 vs. 0.3, P = 0.0266), grade 2 vs. grade 3 (5 vs. 0.3, P = 0.0454). The overall survival (OS) for tumors classified as ‘low-level expression’, was poorer than those with ‘high-level expression’ (118.1 vs. 152.3 months, P = 0.039). LOX expression decreased with increasing NPI: NPI-1 vs. NPI-2 (3 vs. 0, P = 0.0301) and TNM stage: TNM-1 = 3854639, TNM-2 = 908900, TNM-3 = 329, TNM-4 = 1.232 (P = NS). Conclusion: CHIP expression is associated with favorable prognostic parameters, including tumor grade, TNM stage and NPI. CHIP expression predicts OS. LOX expression is associated with improved NPI. In addition to their prognostic utility, mechanistic insights into tumor suppressor function may offer potential therapeutic strategies

Affective Variables In Second Language Acquisition

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98112/1/j.1467-1770.1973.tb00658.x.pd

Voltage sag state estimation based on l_1-norm minimization methods in radial electric power distribution system

Los hundimientos de tensión tienen un alto impacto sobre la correcta operación de equipos y en la continuidad de los procesos en el usuario final de energía eléctrica. Las pérdidas económicas son un problema en crecimiento para las empresas operadoras, para los mismos reguladores y por supuesto para los consumidores finales del servicio de energía eléctrica; es así como se hace necesario la formulación de nuevos métodos matemáticos para el diagnóstico de los hundimientos de tensión. En este sentido, los métodos de estimación de estado buscan determinar la frecuencia o el número de hundimientos de tensión que experimenta un usuario final. En esta área de investigación se han formulado problemas de optimización basados en técnicas como la descomposición en valores singulares, el ajuste de perfiles de tensión y la localización de las fuentes generadoras de los hundimientos de tensión. Los resultados obtenidos usando estas técnicas son imprecisas cuando se consideran las corrientes pre-falla, las fallas con impedancia diferente de cero y los desbalances. Es así como en este artículo se evidenciará que, al considerar estas condiciones reales de las fallas, se obtienen resultados imprecisos para el caso del método de descomposición en valores singulares. A su vez, en este trabajo se propone una nueva formulación matemática del problema de estimación de estado de hundimientos de tensión usando la minimización de la norma-ℓ1. Esta propuesta matemática es aplicada y validada en la red de distribución de prueba de 33 nodos del IEEE.  Únicamente los hundimientos de tensión causados por fallos en la red de distribución serán considerados. Los resultados obtenidos validan una notable mejora en comparación con el método de descomposición en valores singulares y resaltan una innovadora herramienta para la estimación de estado de los hundimientos de tensión en redes radiales de distribución.Voltage sags have a high impact on the proper equipment operation and the electric power end-user processes continuity. Economic losses are a growing problem for the electric utilities, regulators and electric energy final customers and therefore, the formulation of new mathematical methods for voltage sags diagnosis are needed. In this sense, the state estimation methods seek the determination of the frequency or the number of voltage sags that an end-user would experience. In this research area, optimization problems based on techniques such as singular value decomposition, voltage profile curve fitting and voltage sag source location have been formulated. The results of these approaches may be inaccurate when the pre-fault currents, non-zero fault impedances and unbalanced conditions are considered. We will evidence that the results from singular value decomposition method are inaccurate considering these real fault conditions. Also, a new mathematical formulation of the voltage sag state estimation problem based on ℓ1-norm minimization is proposed in this work. The proposed method is applied and validated to the IEEE 33-node test distribution network. Voltage sags caused for network faults are only considered. The results validate a remarkable improvement in comparison with the singular value decomposition method and show an innovative tool for voltage sags state estimation in radial electric power distribution system

Designing for interaction

At present, the design of computer-supported group-based learning (CS)GBL) is often based on subjective decisions regarding tasks, pedagogy and technology, or concepts such as ‘cooperative learning’ and ‘collaborative learning’. Critical review reveals these concepts as insufficiently substantial to serve as a basis for (CS)GBL design. Furthermore, the relationship between outcome and group interaction is rarely specified a priori. Thus, there is a need for a more systematic approach to designing (CS)GBL that focuses on the elicitation of expected interaction processes. A framework for such a process-oriented methodology is proposed. Critical elements that affect interaction are identified: learning objectives, task-type, level of pre-structuring, group size and computer support. The proposed process-oriented method aims to stimulate designers to adopt a more systematic approach to (CS)GBL design according to the interaction expected, while paying attention to critical elements that affect interaction. This approach may bridge the gap between observed quality of interaction and learning outcomes and foster (CS)GBL design that focuses on the heart of the matter: interaction

Higgs-Boson Decay to Four Fermions Including a Single Top Quark Below ttˉt \bar t Threshold

The rare decay modes Higgs $\rightarrow$ four light fermions, and Higgs $\rightarrow$ single top-quark + three light fermions for $m_t<M_H<2m_t$, are presented, and phenomenologically interpreted. The angular correlation between fermion planes is presented as a test of the spin and intrinsic parity of the Higgs particle. In Higgs decay to single top, two tree-level graphs contribute in the standard model (SM); one couples the Higgs to $W^+W^-(\sim gM_W)$, and one to t\bar t(\sim g_{top\;yukawa}=m_t/246\GeV). The large Yukawa coupling for m_t>100\GeV makes the second amplitude competitive or dominant for most $M_H,m_t$ values. Thus the Higgs decay rate to single top directly probes the SM universal mechanism generating both gauge boson and fermion masses, and offers a means to infer the Higgs-$t \bar t$ Yukawa coupling when $H\rightarrow t \bar t$ is kinematically disallowed. We find that the modes $pp\rightarrow Xt\bar t(H\rightarrow t\bar b W^{(*)})$ at the SSC, and $e^+ e^-\rightarrow Z\,or\,\nu\bar{\nu} + (H\rightarrow t\bar b W^{(*)})$ at future high energy, high luminosity colliders, may be measureable if $2m_t$ is not too far above $M_H$. We classify non-standard Higgses as gaugeo-phobic, fermio-phobic or fermio-philic, and discuss the Higgs$\rightarrow$ single top rates for these classes.Comment: 30 pages, 6 figures (figures available upon request); VAND-TH-93/

DIAGNOSIS OF ADVANCED DISTRIBUTION AUTOMATION IN THE BRAZILIAN ELECTRIC SECTOR DISTRIBUTION

ABSTRAC

Charming CP Violation and Dipole Operators from RS Flavor Anarchy

Recently the LHCb collaboration reported evidence for direct CP violation in charm decays. The value is sufficiently large that either substantially enhanced Standard Model contributions or non-Standard Model physics is required to explain it. In the latter case only a limited number of possibilities would be consistent with other existing flavor-changing constraints. We show that warped extra dimensional models that explain the quark spectrum through flavor anarchy can naturally give rise to contributions of the size required to explain the the LHCb result. The D meson asymmetry arises through a sizable CP-violating contribution to a chromomagnetic dipole operator. This happens naturally without introducing inconsistencies with existing constraints in the up quark sector. We discuss some subtleties in the loop calculation that are similar to those in Higgs to \gamma\gamma. Loop-induced dipole operators in warped scenarios and their composite analogs exhibit non-trivial dependence on the Higgs profile, with the contributions monotonically decreasing when the Higgs is pushed away from the IR brane. We show that the size of the dipole operator quickly saturates as the Higgs profile approaches the IR brane, implying small dependence on the precise details of the Higgs profile when it is quasi IR localized. We also explain why the calculation of the coefficient of the lowest dimension 5D operator is guaranteed to be finite. This is true not only in the charm sector but also with other radiative processes such as electric dipole moments, b to s\gamma, \epsilon'/\epsilon_K and \mu\ to e\gamma. We furthermore discuss the interpretation of this contribution within the framework of partial compositeness in four dimensions and highlight some qualitative differences between the generic result of composite models and that obtained for dynamics that reproduces the warped scenario.Comment: 14 page