• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.166-168
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• 1996

This paper presents an power system optimization method which solves real and reactive power dispatch problems using evolutionary computation such as genetic algorithms(GAs), evolutionary programming(EP), and evolution strategy(ES). Many conventional methods to this problem have been proposed in the past, but most these approaches have the common defect of being caught to a local minimum solution. Recently, global search methods such as GAs, EP, and ES are introduced. The proposed methods, applied to the IEEE 30-bus system, were run for 12 other exogenous parameters. Each simulation result, by which evolutionary computations are compared and analyzed, shows the possibility of applications of evolutionary computation to large scale power systems.

• IE interfaces
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• v.20 no.2
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• pp.204-215
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• 2007

This paper addresses vehicle routing planning in freight container transportation systems where a number of loaded containers are to be delivered to their destination places. The system under consideration is static in that all transportation requirements are predetermined at the beginning of a planning horizon. A two-phased procedure is presented for freight container transportation. In the first phase, the optimal model is presented to determine optimal total time to perform given transportation requirements and the minimum of number of vehicles required. Based on the results from the optimal model, in the second phase, ASA(Accelerated Simulated Annealing) algorithm is presented to perform all transportation requirements with the least number of vehicles by improving initial vehicle routing planning constructed by greedy method. It is found that ASA algorithm has an excellent global searching ability through various experiments in comparison with existing methods.

• Journal of information and communication convergence engineering
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• v.3 no.1
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• pp.33-37
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• 2005

One of the most important feature of the Mobile Manipulator is redundant freedom. Using the redundant freedom, Mobile Manipulator can move various mode, perform dexterous motion. In this paper, to improve robot job ability, as two robots perform a job in co-operation control, we studied optimal position and posture of Mobile Manipulator with minimum movement of each robot joint. Kinematics of mobile robot and task robot is solved. Using mobility of Mobile robot, weight vector of robots is determined. Using Gradient methode, global motion trajectory is minimized. so the job which Mobile Manipulator perform is optimized. The proposed algorithm is verified with PURL-II which is Mobile Manipulator combined Mobile robot and task robot. and discussed the result.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.968-970
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• 1993

In this paper, the loss components of IPMSM(Inteiror Permanent Magnet Synchronous Motor) is derived. To maximize the efficiency of the motor, a design method that optimizes the design variables is proposed Objective function consists of stator winding loss, core loss, and mechanical loss. Simulated annealing is used as the optimization method which is appropriate for finding the global minimum of nonlinear function with many local minima. Through the simulation of the motor characteristics, the prominence of the proposed design method is verified.

• Journal of Ocean Engineering and Technology
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• v.27 no.5
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• pp.36-42
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• 2013

We present the optimum design for the cross-sectional(sizing) and shape optimization of truss structures with natural frequency constraints. The optimum design method used in this paper employs continuous design variables and the Harmony Search Algorithm(HSA). HSA is a meta-heuristic search method for global optimization problems. In this paper, HSA uses the method of random number selection in an update process, along with penalty parameters, to construct the initial harmony memory in order to improve the fitness in the initial and update processes. In examples, 10-bar and 72-bar trusses are optimized for sizing, and 37-bar bridge type truss and 52-bar(like dome) for sizing and shape. Four typical truss optimization examples are employed to demonstrate the availability of HSA for finding the minimum weight optimum truss with multiple natural frequency constraints.

• Bulletin of the Korean Chemical Society
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• v.16 no.12
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• pp.1153-1162
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• 1995

The conformational details of β-lactose are investigated through molecular dynamics simulations in conjunction with the adiabatic potential energy map. The adiabatic energy map generated in vacuo contains five local minima. The lowest energy structure on the map does not correspond to the structure determined experimentally by NMR and the X-ray crystallography. When aqueous solvent effect is incorporated into the energy map calculation by increasing the dielectric constant, one of the local minima in the vacuum energy map becomes the global minimum in the resultant energy map. The lowest energy structure of the energy map generated in aquo is consistent with the one experimentally determined. Molecular dynamics simulations starting from those fivelocal minima on the vacuum energy map reveal that conformational transitions can take place among various conformations. Molecular dynamics simulations of the lactose and ricin B chain complex system in a stochastic boundary indicate that the most stable conformation in solution phase is bound to the binding site and that there are conformational changes in the exocyclic region of the lactose molecule upon binding.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.15 no.25
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• pp.23-31
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• 1992

This paper is concerned with an n jobs one machine Job shop scheduling problems in which all jobs have a common due date and unequal penalties occur when a job is completed before or after due date. The objective is to determine an optimal sequence and the corresponding common due date that yield the global minimum value of a penalty function Then a sequence that minimize the penalty function globally is a V-shaped sequence Using the idea of linear equations and a LGP(Linear Goal Programming), this paper shows that LGP and MAD(Mean Absolute Deviation) are equivalent problems. Therefore an efficient algorithm that is developed for MAD problem holds for LGP problem and vice-versa. A numerical example to account for the algorithm is provided.

• Journal of the Optical Society of Korea
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• v.15 no.1
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• pp.22-29
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• 2011

We analyze aberrations in an optical laser printer system in order to know how to determine an allowable non-uniformity of the movement of a light spot, how to determine allowed variation of spot sizes, and how to minimize the influence of these deviations on technological errors. In this paper, the correction and the tolerance of distortion are analyzed by using the concept of zonal and global distortions. The tolerance of field curvature is also obtained from Gaussian beam properties. In order to reduce the change of the entrance pupil position and to make a more compact laser printer system the minimum size of the rotator is exactly derived from the geometry with the introduction of the shift angle of the input beam.

• Steel and Composite Structures
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• v.33 no.2
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• pp.277-298
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• 2019

Concrete filled steel tubular (CFST) column joints with composite beams have been widely used as lateral loading resisting elements in civil infrastructure. To better utilize these innovative joints for the application of structural seismic design and analysis, it is of great importance to investigate the dynamic behavior of the joint under cyclic loading. With this aim in mind, a novel phenomenal model has been put forward in this paper, in which a Bouc-Wen hysteresis component is employed to portray the strength and stiffness deterioration phenomenon caused by increment of loading cycle. Then, a modified chicken swarm optimization algorithm was used to estimate the optimal model parameters via solving a global minimum optimization problem. Finally, the experimental data tested from five specimens subjected to cyclic loadings were used to validate the performance of the proposed model. The results effectively demonstrate that the proposed model is an easy and more realistic tool that can be used for the pre-design of CFST column joints with reduced beam section (RBS) composite beams.

• Coupled systems mechanics
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• v.11 no.3
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• pp.259-266
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• 2022

Non-Traditional Optimization methods are successfully used in solving many engineering problems. Shaft is one of important element of machines and it is used to transmit power from a machine which produces power to a machine which absorbs power. In this paper, ten non-traditional optimization methods that are ALO, GWO, DA, FPA, FA, WOA, CSO, PSO, BA and GSA are used to find minimum weight of hollow shaft to get global optimal solution. The problem has two design variables and two inequality constraints. The comparative results show that the Particle Swarm Optimization outperforms other methods and the results are validated using ANSYS.