• Journal of Ocean Engineering and Technology
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• v.26 no.4
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• pp.1-7
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• 2012

This paper deals with the global path planning problem for AUVs (autonomous underwater vehicles) in a tidal current field. The previous researches in the field were unsuccessful at simultaneously addressing the two issues of obstacle avoidance and tidal current-based optimization. The use of a genetic algorithm is proposed in this paper to move past this limitation and solve both issues at once. Simulation results showed that the genetic algorithm could be applied to generate an optimal path in the field of a tidal current with multiple obstacles.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.12
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• pp.171-176
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• 2010

This paper presents the electric field for 22.9[kV]/380[V], 2[MVA] mold transformer are analysed using FEM(finite element method). The electric field was calculated for the voltage applied to the transformer. Then, it is analysed that the maximum electric field occurred between high voltage turns. Capacitance is calculated with energy method. Surge impulse test simulation is studied by modeling circuit with capacitance and inductance. This paper obtain the result that is about influence of electric field in distribution mold transformer adopted.

• Journal of the Korean Society of Safety
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• v.17 no.2
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• pp.32-38
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• 2002

In this paper, a new approach for the SynRM(Synchronous Reluctance Motor) control which ensures producing MTPA(Maximum Torque per Ampere) over the entire field weakening region is presented. In addition, this paper presents a speed sensorless control scheme of SynRM using flux observer. Also, by adjusting the base speed for the field weakening operation according to the flux level, the current and voltage limit, the smooth and precise transition into the field weakening operation can be achieved. The validity of the proposed scheme is verified through simulation.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.2
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• pp.225-232
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• 1994

In this paper, a new approach for the induction machine control whih ensures producing maximum torque per ampere over the entire field weakening region is presented. In addition, the relation of the output torque capability with the leakage factor of the machine is examined. Also the smooth and precise transition into the field weakening operation can be achieved by adjusting the base speed for the field weakening operation according to the flux level, the current limit and the voltage limit. The proposed is verified through simulation and experiment for a 5hp laboratory induction motor drive system.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.1
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• pp.75-82
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• 2004

We have studied the influence of rubbing directions on electro-optic characteristics of the fringe field driven hybrid aligned nematic liquid crystal (LC) cell by computer simulation. When a LC with positive dielectric anisotropy is used, the results show that the driving voltage and transmittance decreases as the rubbing direction with respect to horizontal electric field direction increases. The reason for decrease in light transmission is the increase of tilt angle on the center of common electrode. In this paper, we have studied how the rubbing angle effects on the transmittance of the cell by investigating a distribution of electric field and LC director.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.63-64
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• 2006

Here we present detailed simulation results of trench field stop IGBTs. Besides the reduced on-state voltage drop there is also an Increase of forward blocking voltage. A trench gate IGBT has low on-state voltage drop mainly due to the removal of the JFET region and a field stop IGBT has high forward blocking voltages due to the trapezoidal field distribution under blocking condition. We have simulated the static characteristics of TIGBT with field stop technology by 2D simulator(MEDICI). The simulated result of forward blocking voltage and on-state voltage drop is about 1,408V and 1.3V respectively at $110{\mu}m$ N-drift thickness.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.12
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• pp.1003-1006
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• 2017

In this paper, during radio-frequency performance testing in a shield box, the non-uniform electric field distribution between multiple mobile phones is examined by numerical simulation, and two ways to improve the field uniformity among mobile phones under test are proposed. The results demonstrate that the proposed methods can greatly improve the field uniformity.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.4
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• pp.476-480
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• 2012

In this paper, artificial potential field(APF) is applied to formation control for the leader-following swarm robot. Furthermore, APF is constructed by applying the electrical field model. Moreover, to model the obstacle effectively, each obstacle has different form due to the electrical field equation. The proposed method is formed as two sub-objective: path planning for the leader-robot and following-robots following the leader-robot. Finally, simulation example is given to prove the validity of proposed method.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.957-960
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• 2003

We have studied the influence of rubbing directions on electro-optic characteristics of the fringe field driven hybrid aligned nematic liquid crystal (LC) cell by computer simulation. When a LC with positive dielectric anisotropy is used, the results show that the driving voltage and transmittance decreases as the rubbing direction with respect to horizontal electric field direction increases. The reason for decrease in light transmission is the reduction of twist angle and increase of tilt angle on the center of common electrode. In this paper, we have studied how the rubbing angle effects on the transmittance of the cell by investigating a distribution of electric field and LC director.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.323-326
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• 2004

The this paper is describing about the electric field distribution due to the roughness in Aramid insulating paper for electric machine. The insulting and pressboard paper have been used at electric insulating of traction motor and generators. There was a change investigation of the electric field distribution according to the roughness of specimen by simulation program of Electro. We studied the electric field distribution using boundary element method for Aramid insulator. We find out an optimal condition in insulating paper of electric machine.