http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Tahir Khurshaid,Abdul Wadood,Saeid Gholami Farkoush,김창환,조남훈,이상봉 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.1
The coordination of directional overcurrent relays (DOCR) plays a very important role for maintaining security and enhancing reliability in the electrical power system. This paper presents the coordination of directional overcurrent relay using the modified particle swarm optimization (MPSO) technique. In order to improve the quality of a solution a local search algorithm is embedded to the original particle swarm optimization (PSO). Time dial settings had been optimized for directional overcurrent relays. In PSO technique on implementing the DOCR, being a highly constrained optimization problem that takes into consideration the linear programming. To handle such constraints a modification to PSO algorithm has been introduced. MPSO has achieved a lot of relaxation to its easy implementation, modesty and robustness. The proposed algorithm had been tested on IEEE 6-bus, IEEE 15-bus system and IEEE 30-bus system using MATLAB computer programming.
Khalil Akhtar,Syed Wadood Ali Shah,Assar Ali Shah,Muhammad Shoaib,Syed Kashif Haleem,Nighat Sultana 한국응용생명화학회 2017 Applied Biological Chemistry (Appl Biol Chem) Vol.60 No.4
The aim of present study was to evaluate the antihyperglycemic and antihyperlipidemic effects of aerial parts of Rubus ulmifolius Schott on streptozotocin (STZ)- induced diabetic albino mice. A total of 48-, 60-day-old either sex (male and female) albino mice were treated with, normal control; 2% Tween-80 suspension (diabetic control); glibenclamide (500 lg/kg/orally); RU methanol extract (150 mg/kg/orally) (RUCrd1); RU methanol extract (300 mg/kg/orally) (RUCrd2); RU chloroform extract (150 mg/kg/orally) (RUC); RU ethyl acetate extract (150 mg/kg/orally) (RUE); and RU butanol extract (150 mg/kg/orally) (RUB) for a period of 15 days. Diabetes was induced in albino mice by single intraperitoneal injection of streptozotocin (50 mg/kg/b/w). After 15 days, group treated with glibenclamide, RUCrd1, RUCrd2, RUC, RUE and RUB exhibited a significant (P[0.05) decrease in blood glucose level as compared to diabetic control groups. The total cholesterol, triglycerides and low-density lipoproteins as well as serum creatinine level, serum glutamate pyruvate transaminase, serum glutamate oxaloacetate transaminase and alkaline phosphatase were also significantly (P[0.05) decreased in glibenclamide, RUCrd1, RUCrd2, RUC, RUE and RUB groups albino mice as compared to diabetic control. It was concluded that Rubus ulmifolius Schott extract has positive effect as hypoglycemic and antihyperlipidemic on diabetic albino mice.
Farooq, A.,Zubair, M.,Wadood, H.Z.,Deen, K.M. The Korean Electrochemical Society 2021 Journal of electrochemical science and technology Vol.12 No.4
This research work aims to investigate the effect of the aerobic bacterium, Pseudomonas aeruginosa on the mechanical and electrochemical properties of the 316L stainless steel and α-brass. These properties of both the alloys were determined after 7 days of exposure to the controlled and inoculated media at 37℃. The microstructural and electrochemical test results revealed the deleterious effects of Pseudomonas aeruginosa. After exposure to the inoculated medium, the scanning electron microscopy (SEM) results showed the larger pitting and formation of relatively dense biofilm on α-brass compared to 316L stainless steel. The tensile strength and hardness of 316L stainless steel were slightly affected after exposure to the controlled and inoculated media. After exposure to the controlled medium and inoculated media, the tensile strength of the α-brass was least affected but a significant decrease in the hardness (from 165 HV to 124 HV) was observed due to the severe attack induced by the Pseudomonas aeruginosa. Similarly, the open-circuit potential of the 316L stainless steel in the inoculated medium was measured to be less active (-410 mV vs Ag/AgCl) than α-brass (-550 mV vs Ag/AgCl). In the inoculated medium, potentiodynamic polarization curves confirmed the severe attack of Pseudomonas aeruginosa on α-brass (7.15 × 10<sup>-2</sup> mm/year) compared to 316L stainless steel which registered a corrosion rate of 5.14 × 10<sup>-4</sup> mm/year.
Wali Muhammad,Wilayat Husain,Anjum Tauqir,Abdul Wadood 대한용접·접합학회 2020 대한용접·접합학회지 Vol.38 No.5
In this study, the Taguchi Design of Experiment method was used to determine the optimal Friction Stir Welding (FSW) parameters for improving the mechanical properties of AA 2014-T6 alloy butt joints. The three most significant parameters - tool rotational speed, tool linear travel speed and tool tilt angle - were optimized using the L9 orthogonal array design. The optimal welding parameters for the maximum tensile strength were determined by analyzing the signal-to-noise (S/N) ratio. A regression model was developed for the desired responses. The optimal tensile strength was achieved at the 1000 rpm, rotational speed, 600 mm/rev welding speed, and 2° tool title angle. The results were confirmed using a steady-state heat transfer model generated from the COMSOL Multiphysics Finite Element software. The identified optimal conditions were verified by experimental validation tests. The experimental results were consistent with the predicted values. Analysis of variance (ANOVA) was conducted to determine the effects of individual parameters and to identify the most significant process parameter. ANOVA indicated that the most significant factor affecting the mechanical behavior of the joint was the tool rotation speed followed by the linear travel speed.
Gholami Farkoush, Saeid,Khurshaid, Tahir,Wadood, Abdul,Kim, Chang-Hwan,Kharal, Kumail Hassan,Kim, Kyu-Ho,Cho, Namhun,Rhee, Sang-Bong Hindawi Limited 2018 Complexity Vol.2018 No.-
<P>A large number of electromagnetic transient studies have been analyzed for finding the overvoltage behavior of power system. A grounding grid of power system is so important for reducing the effect of overvoltage phenomena during a short-circuit event. Two sections are important in grounding system behavior: soil ionization and inductive behavior; this paper focuses on the inductive manner of grounding grid. The grounding grid is considered as a conductor segment; each conductor segment acts as a grounding unit. In this paper, the transient methodology is introduced to investigate the lightning effect on grounding body at each point of grounding grid in normal and optimized conditions. Genetic algorithm is applied for regular and irregular grounding grid to obtain best values of mesh size with the lower ground potential rise (GPR) as compared with the normal condition for more safety. The grounding grid is a combination of inductance, resistance, and capacitance. This model is suitable for practical applications related to fault diagnosis. Several voltages on different positions of grounding grid are described in this paper using ATP-EMTP and genetic algorithm. The computer simulation shows that the proposed scheme is highly feasible and technically attractive.</P>
Gray Wolf Optimizer for the Optimal Coordination of Directional Overcurrent Relay
Kim, Chang-Hwan,Khurshaid, Tahir,Wadood, Abdul,Farkoush, Saeid Gholami,Rhee, Sang-Bong The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.3
The coordination of directional overcurrent relay (DOCR) is employed in this work, considering gray wolf optimizer (GWO), a recently designed optimizer that employs the hunting and leadership attitude of gray wolves for searching a global optimum. In power system protection coordination problem, the objective function to be optimized is the sum of operating time of all the main relays. The coordination of directional overcurrent relays is formulated as a linear programming problem. The proposed optimization technique aims to minimize the time dial settings (TDS) of the relays. The calculation of the Time Dial Setting (TDS) setting of the relays is the core of the coordination study. In this article two case studies of IEEE 6-bus system and IEEE 30-bus system are utilized to see the efficiency of this algorithm and the results had been compared with the other algorithms available in the reference and it was observed that the proposed scheme is quite competent for dealing with such problems. From analyzing the obtained results, it has been found that the GWO approach provides the most globally optimum solution at a faster convergence speed. GWO has achieved a lot of relaxation due to its easy implementation, modesty and robustness. MATLAB computer programming has been applied to see the effectiveness of this algorithm.