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In this paper, a D-Q model of fuzzy based unified power flow controller (UPFC) has been proposed to control the active and reactive power flow through the transmission lines. Power loss reduction also intends with the proposed UPFC controller. The UPFC's shunt and series controllers are developed based on D-Q fuzzy logic (FL) controller, which has been(More)
This paper studies the effect of time delay and harvesting on the dynamics of the predator-prey model with a time delay in the growth rate of the prey equation. The predator and prey are then harvested with constant rates. The constant rates may drive the model to one, two, or none positive equilibrium points. When there exist two positive equilibrium(More)
Titanium-coated surfaces are prone to tiny defects such as very small cracks, which are not easily observable by the naked eye or optical microscopy. In this study, two new thresholding methods, namely contrast-adjusted Otsu's method and contrast-adjusted median-based Otsu's method, are proposed for automated defect detection system for titanium-coated(More)
This study examines a new approach to selecting the locations of unified power flow controllers (UPFCs) in power system networks based on a dynamic analysis of voltage stability. Power system voltage stability indices (VSIs) including the line stability index (LQP), the voltage collapse proximity indicator (VCPI), and the line stability index (Lmn) are(More)
Global demand for power has significantly increased, but power generation and transmission capacities have not increased proportionally with this demand. As a result, power consumers suffer from various problems, such as voltage and frequency instability and power quality issues. To overcome these problems, the capacity for available power transfer of a(More)
In this paper we present two new numerical methods for unconstrained large-scale optimization. These methods apply update formulae, which are derived by considering different techniques of approximating the objective function. Theoretical analysis is given to show the advantages of using these update formulae. It is observed that these update formulae can(More)
Attitude control of a satellite is performed by controlling two main parameters, angular speed and altitude. An inappropriate value for each of these parameters can lead the satellite to be lost in space or fall to the earth. This paper presents altitude and speed control of geostationary satellites by means of two controllers, the first one is a PID(More)
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