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Although in recent two decades, the concept of Dielectric Barrier Discharges (DBDs) have been developed in ozone production well, air pollution control, plasma screens and control of chemical, and biological and medical processes, employment of this concept for high voltage applications to improve insulation performance as an alternative to the pressurized gas-insulated systems (GIS) utilizing SF6, is still in research phase. In this paper, the enhancement of insulation performance using DBD and with increasing charge densities on the barrier surfaces in uniform electric filed has been statically modeled. This means that the dynamics of the development of space charges and the manner they sit on the barrier surfaces are ignored and only DBD concepts considering different amounts of surface charges on the barrier surfaces are evaluated. Also the influence of various parameters, such as permeability of the dielectric material, its thickness, and length of air gap, on the enhancement of insulation performance are evaluated. Then an algorithm for the formation of space charges, settling on the barrier surfaces and electric filed modification in the air gap for three types of voltage including DC, AC and lightning impulse, is simulated and evaluated using MATLAB. In this modeling, dielectrics are considered as non-insulating with some electrical conductivity.

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This paper presents a probabilistic confidence-interval based method for optimal placement of shunt capacitors in distribution networks by considering probabilistic characteristics of loads. The main objective function are reducing loss and improving the voltage profile. Backward forward sweep method has been employed to obtain the power flow results in distribution system. In addition, Integer Harmony Search Algorithm has been used to solve the optimization problem. The probabilistic aspects of problem have been solved using point estimation (PE) method. The novelty of this paper is introducing a confidence interval index using Gram-Charlier expansion. This index shows the risk of system to violate its security constraints when loads are considered as stochastic random variables. Using this index, planners can find the optimal sitting and sizing of capacitors in distribution systems based on their desired level of risk. Verification of the proposed method has been tested on 33-bus radial distribution system. Results demonstrate the effectiveness and merits of the proposed method.

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Since it is essential to deliver smoothed sinusoidal voltage to the customers, diagnosing power quality (PQ) events has played important role in power delivery and conversion. This diagnostic scheme should be accurate to classify PQ events from other events in power system. Also it should be fast enough to rapidly mitigate PQ events. In this paper, an algorithm based on Core Vector Machine (CVM) has been introduced to classify power quality events. Feature selection method has also been applied to increase the accuracy of the classifier’s algorithm. Some features have been selected among several others extracted by wavelet transform. In addition, eight different classes are simulated due to the corresponding equations used in previous studies. Evaluating the performance of the algorithm, different indices have been used to assess the operation of the classifier’s algorithm. Simulations results show the robust capability of the proposed algorithm to classify the PQ events

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Some economists believe that economic crises and problems, such as economic volatility, high unemployment and inflation and the social losses, stem from the government's economic intervention and the implementation of its imperative policies. In this regard, the lack of implementation of the government’s imperative policies by central bank and its independence is still a controversial issue. In the present paper, using Stackelberg model and game theory approach, the efficiency of bond issuance is evaluated as a result of central bank independence and its effect on social loss. For this purpose, a 3-player game including government, central bank and speculators having different objective functions, is designed for Iran. Modeling and numerical analyzing are performed using softwares GAMS and MAPLE during 2005 to 2009. According to minimization of social loss, the results indicate if the government does not play a dominant leadership role, and conversely, if the central bank exerts its leadership in making monetary policy via open market operations (central bank independence), the social loss can be reached to its minimum level.