• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.96-98
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• 2005

This paper describes a monitoring system that monitors power quality and undesirable accidents when distributed generations are connected to the power grid. Prior to develop and operate a physical monitoring system, we constitute a simulation device to simulate the monitoring processes for the situations. The simulation system consists of the server and the client that connected by communication line. This system has various functions to monitor the power quality and the connection situation. Those functions are generation, transmission, acquisition and analysis of the simulated power data. This research seems very important to get the reliable and intelligent connection algorithm through the result of simulated monitoring system. Also hereafter, as this system uses the remote monitoring system through network and constitute the data base(DB), it will play an important role in building the automation of power system efficiently and systematically.

• Journal of Mechanical Science and Technology
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• v.14 no.2
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• pp.177-187
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• 2000

Dilution is an important factor which influences the properties of clad layer. In this paper the change of dilution during laser cladding and the control of dilution are simulated by a finite element method. The adaptive mesh method is adopted for the time-dependent finite element method computation so that the shape of melt pool can be well represented. The situation of the width control of melt pool is also simulated, which indicates that the dilution can be controlled if the width of melt pool is controlled. Computational results indicate that if a line energy (input energy per unit distance) remains constant the dilution will increase with time, especially at the beginning. Simulation results show that it is possible to control dilution in a certain range if the line energy decreases with time. Experiment of Nd: YAG laser cladding with wire feeding is performed. Experiment results coincide well with the FEM results.

• Journal of Convergence Society for SMB
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• v.4 no.2
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• pp.33-39
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• 2014

In this paper, basic backgrounds about capsule endoscopy are introduced, and the aims and objectives are also illustrated. Methodology and mathematical model for LuGre model were investigated to analyse system characteristics. A nonlinear friction model, the stick-slip motion system based on LuGre friction model was used to simulate the motion of capsule endoscopy inside human body. Under the different situation, LuGre friction model was simulated by Matlab Simulink software. The entire cycle of motion and the influence of parameters towards to velocity are fully simulated.

• Journal of the Korea Institute of Military Science and Technology
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• v.7 no.1
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• pp.59-65
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• 2004

Survivability of the general purpose warhead during the target impact was studied. We first simulated the penetration phenomena and temporarily defined the survivability of the warhead at the impact situation. Next we launched the warhead projectiles by using Counter Mass Gun(CMG) system against the simulated specific steel target. The recovered warheads were carefully investigated and the penetration behaviors were analyzed. As a result the warhead can be hardened efficiently to enhance the survivability with the help of CMG test ＆ analysis.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.16 no.2
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• pp.185-193
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• 1987

The heat transfer characteristics from a solid sphere in a fluctuating air flow is simulated numerically in the range of the Reynolds numbers, $1\;{\leqslant}\;Re\;{\leqslant}\;40.$ Such a situation may be encountered in forced convection from a heated spherical particle in a sound field or oscillat-ing flow. The amplitude and phase delay in the heat transfer response to the flow oscillation are computed for a small amplitude flow. The instantaneous response of heat transfer is simulated for the large amplitude oscillation and compared with the quasi-steady response. The effect of the oscillation on the time - mean value in the local and overall heat transfer rate is discussed along with the change in the flow .field.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.371-376
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• 2007

This paper describes a study to determine proper escape way interval for the design phase of single bored double track tunnel. Among many methods which determine escape way interval, we choose a QRA(Quantitative Risk Analysis) method. But a different method must be chosen differ from other country because of special design situation of Korea. So, it is necessary to develop a method which considers a special design condition of Korea. Because fire accidents of railway tunnel are a rare event, simulated situation can be produced by CFD simulation and evacuation analysis simulation. However, it is generally difficult to estimate of fatalities from these methods, so a concept of FED is introduced to estimate of fatalities. Quantification process provides effective results for practical design stage and the result were employed in design.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.10
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• pp.431-435
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• 2003

It is very difficult and dangerous to measure PD(Partial Discharges) from high voltage equipments in outdoor situation. But that is very important thing for preventing them from more serious accident by defects made by insulating degradation. This paper provides useful method to detect PD signals easily without any dangerous situation. Electric field sensor by the principle of capacitor can detect PD signals without direct connection between sensor and high voltage equipment and has very wide frequency range suitable for noise rejection. Electric field sensor and related circuit for processing PD signal show good performance as a PD sensor when it is applied to simulated high power equipment generating PD pulses.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1480-1481
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• 2006

It is very difficult and dangerous to measure partial discharge from high voltage equipment in outdoor situation. But that is very important thing for preventing serious accidents from defects which originated in insulating degradation. This paper provides useful method to detect PD signals easily without any dangerous situation. Electric field sensor by the principle of capacitor detect PD signals without direct electrical connection between sensor and high power equipment and has very wide frequency range suitable for noise rejection. Electric field sensor and related circuit for processing PD signal showed good performance as a PD sensor when it is applied to simulated high power equipment generating PD pulse.

• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.70-72
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• 1998

Because of using PWM inverters and converters. The problems of insulation breakdown is emerging in both high voltage motors and general motors. In conventional methods, the viewpoint of surge problems is wave propagation with or without cable and inverter. For the purpose of knowing the situation of insulation breakdown, the end-turn coil of windings in the motor winding insulation structure is modelled by FEM, and field analysis of that is done. For first step, only end-turn coil is modelled and the model is simulated with FEM by approximating the resistivity of metallic foil surrounding insulation layers with having nonlinear property. Next, the result of simulation with nonlinear resistivity are compared with the result of linear resistivity. Because of microscope analysis, there is the problem of generalization but the situation of corona discharge in end-turn coil will be explained from this simulation.

• Transactions on Control, Automation and Systems Engineering
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• v.4 no.2
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• pp.176-187
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• 2002

This paper focuses on the study of simulation and evolution of Micro Air Vehicles. Micro Air Vehicles or MAVs are small flying robots that are used for surveillance, search and rescue, and other missions. The simulated robots are designed based on realistic characteristics and the brains (controllers) of the robots are generated using genetic algorithms, i .e., simulated evolution. The objective for the experiments is to investigate the effects of robot team size and topology (simulation environment) on the evolution of simulated robots. The testing of team sizes deals with finding an ideal number of robots to be deployed for a given mission. The goal of the topology experiments is to see if there is an ideal topology (environment) to evolve the robots in order to increase their utility in most environments. We compare the results of the various experiments by evaluating the fitness values of the robots i .e., performance measure. In addition, evolved robot teams are tested in different situation in order to determine if the results can be generalized, and statistical analysis is performed to evaluate the evolved results.