Optimal Arrangement of Egyptian O.H.T.Ls using Genetic Algorithm
ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING (Impact Factor: 0.37). 02/2014; 39(2):1049-1059. DOI: 10.1007/s13369-013-0698-7
This paper focuses on reduction of electromagnetic field emissions and hence reduction of the right-of-way (ROW) regarding re-arrangements of the conductors of 500 kV single-circuit and 220 kV double-circuit Egyptian overhead transmission lines (OHTLs). The technique used in this paper is based on optimal conductor arrangements obtained using the Genetic Algorithm. The input data to the genetic algorithm include the clearances between conductors and earthed objects, the clearances between individual conductors, and the calculated values of electric and magnetic fields (EMFs) and the radio interference (RI). 3-D integration technique is used to calculate both the EMFs under the OHTLs. On the other hand, the excitation function method is used to calculate the RI. The EMFs are calculated at the ground surface under OHTLs and hence the ROW can be indicated. The comparison between the results of both conventional and optimal arrangements indicates the effective of the optimal one.
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ABSTRACT: Purpose ‐ Expert Cloud as a new class of Cloud computing systems enables its users to request the skill, knowledge and expertise of people by employing internet infrastructures and Cloud computing concepts without any information of their location. Job scheduling is one of the most important issue in Expert Cloud and impacts on its efficiency and customer satisfaction. The purpose of this paper is to propose an applicable method based on genetic algorithm for job scheduling in Expert Cloud. Design/methodology/approach ‐ Because of the nature of the scheduling issue as a NP-Hard problem and the success of genetic algorithm in optimization and NP-Hard problems, the authors used a genetic algorithm to schedule the jobs on human resources in Expert Cloud. In this method, chromosome or candidate solutions are represented by a vector; fitness function is calculated based on response time; one point crossover and swap mutation are also used. Findings ‐ The results indicate that the proposed method can schedule the received jobs in appropriate time with high accuracy in comparison to common methods (First Come First Served, Shortest Process Next and Highest Response Ratio Next). Also the proposed method has better performance in term of total execution time, service+wait time, failure rate and Human Resource utilization rate in comparison to common methods. Originality/value ‐ In this paper the job scheduling issue in Expert Cloud is pointed out and the approach to resolve the problem is applied into a practical example.
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ABSTRACT: Accurate monitoring and determination of the trajectory and relative position are two very important concerns during drilling the connection of two wells to form a U-shaped horizontal well. The composite error circle based on trajectory uncertainty analysis is introduced. The timing of using the magnetic ranging tool is established by comparing the diameter of the composite error circle with that of the ranging scope of the magnetic ranging tool. The profile is designed, and the key extension formula is given according to the characteristics of the magnetic ranging tool. The measurement principle of a Rotating Magnetic Ranging System, which is widely used during the drilling of U-shaped wells, is introduced in order to analyze the relative position uncertainty. Through analysis of the error sources, a covariance matrix of the relative position uncertainty is constructed, and its error ellipsoid and error ellipse are determined. The error ellipse is found to be beneficial in using the magnetic ranging tool during the drilling of U-shaped horizontal wells by comparing the semi-axis of the error ellipse and the radius of the borehole.
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