• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.546-547
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• 2013

This paper proposes an arc fault circuit interrupter (AFCI) using the distorted voltage wave in electric arc faults. It perceives a voltage instantaneously at the time of voltage drop. and occurrence. It is an AFCI of the new concept which operates with high reliability. The primary reason of electric fire is arc and spark. It prevents an electric fire or an electric leakage accident with quick responsiveness. Earth Leakage Circuit Breaker(ELB), Molded_case Circuit Breaker (MCCB) or Residual Current Protective Device(RCD) can not cut off electric arc or spark to be a major factor of electrical fire. This theory will be able to intercept an arc or a spark. which occurrence with periodic. Consequently It raises a reliability and validates a practicality of RCD.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.53-54
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• 2013

디지털 제품의 사용 증가로 직류를 사용하는 부하가 급증하고, 태양광발전 등 직류발전의 보급이 확대 되며 직류배전에 대한 관심이 높아지고 있다. 기존 영상변류기(ZCT; Zero phase sequence Current Transformer)를 사용하여 누설전류를 감지하는 교류배전용 차단기는 영상변류기의 특성상 직류에서 적용이 불가능하다. 이에 따라 직류배전에서 누설전류에 의한 사고를 방지하기 위해서 누설전류를 검출하고 차단할 수 있는 장치 개발이 필요하다. 본 논문에서는 직류에서 검출에 문제가 없는 Fluxgate current transducer를 이용하여 직류배전에서 사용 가능한 검출기를 개발하였다.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.04a
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• pp.115-118
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• 2004

In this paper, a Fiber Bragg Grating (FBG) sensor system for smart structures is described. FBGs are well-suited for long term and extremely severe experiments, where traditional strain gauges fail. In the system, a reflect wave-length measurement method which employs a tunable light source to find out the center wave-length of FBG sensor is used. We applied the FBG system to composite repairing structures and beam column joint of building structure. We also applied the system to nuclear energy power plant for structural integrity test to measure the displacement of the structure under designed pressure and to check the elasticity of the structure by measuring the residual strain. The system works very well and it is expected that it can be used for a real-time strain, temperature and vibration detectors as parts of smart structures.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2000.11a
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• pp.238-244
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• 2000

FBGs have been extensively used as strain sensors or temperature sensors in a variety of applications related to composites because of embedding ability, small size and multiplexing capability. We inspected embedding environments inside composites with optical fiber by microscope analysis and birefringence characteristics of FBG embedded into textile composite laminate by cure monitoring using a high power WSFL. The cure monitoring of the cases with the striped FBG and the recoated FBG provided comprehensive understandings about the birefringence effect induced by the transverse stress. And these results allowed to consider a recoating method as an important tool to relieve birefringence.

• Proceedings of the IEEK Conference
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• 2001.06e
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• pp.189-192
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• 2001

A new configuration of acoustic echo canceler with stepsize predictor and comparator is proposed in this paper. Conventional acoustic echo cancelers using ES(Exponential Step)algorithm has fast convergence speed, but very weak in interference of environment. The proposed stepsize predictor and comparator improve conventional acoustic echo canceler's defects. The Stepsize predictor generates a stepsize value using residual power of error signal. The stepsize comparator selects the stepsize value that is better performance in a acoustic echo canceler using a stepsize decision factor. The Simulation results show superiority of the proposed acoustic echo canceler in environment interference.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.637-639
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• 1999

ZnO varistors have been widely used to protect power system and electronic system against overvoltages based on their excellent nonlinearity. In order to increase their protection capability, ZnO varistors are chosen by several electrical parameters according to their applications, namely 1mA DC voltage, 1eakage currents, impulse residual voltages, withstanding capability to impulse surge, and energy absorption capability. But these Parameters have scattering properties due to the nonuniformity of electrical characteristics. In this study, the effect of the microstructrual nonuniformity on the surge absorption capability of ZnO varistors.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.250-252
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• 2007

In this paper presents a control algorism for myoelectric hand prosthesis(MHP) with 2 degree of freedom(DOF), which consists of a mechanical hand, a surface myoelectric sensor(SMES) for measuring myoelectric signal, a control system and a charging battery. The actuation for the 2-DOF hand functions such as grasping and wrist rotation was performed by two DC-motors, and controlled by myoelectric signal measured from the residual forearm muscle. The two controllers were made of a RISC-type microprocessor, and its software was executed on a real-time kernel. The experimental results were showed that the proposed a control algorism is feasible for the MHP.

• Journal of the korean Society of Automotive Engineers
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• v.8 no.1
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• pp.75-86
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• 1986

This paper describes a simulation program of intake and exhaust processes in a 4-stroke S.I. engine and also studies the relationship among various engine parameters under different engine speed and load conditions. This simulation program includes the engine cylinder model for the intake and exhaust processes and its formulation and evaluates the system characteristics such as inlet mass, pumping work and residual gas in the cylinder-which influence on power output, fuel economy and exhaust emissions. In order to evaluate the accuracy of the simulation program, predicted results were compared with the experimental data obtained on the 4-stroke, 4-cylinder gasoline engine and satisfactory agreement was obtained.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.5-6
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• 2014

According to 2013 fire statistical yearbook in the National Emergency Management Agency, the main cause of an electrical fire are classified to short circuit fault, overload fault, electric leakage, partial disconnection, and joint/contact badness. The occurrence factor of fire is electric arc or spark accompanied with electrical faults. Residual Current Protective Devices(RCDs) of high sensitivity type used at single phase (220V) cut off earth leakage and overload but the RCDs can not cut off electric arc or spark to be a main cause of electrical fire. To be improved on such problem, this thesis is proposed to a auxiliary control device for RCD cut off electric arc or spark.

• Journal of Korean Institute of Fire Investigation
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• v.8 no.1
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• pp.41-48
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• 2006

The purpose of this study is to identify the fire danger of the electric radiant heating system and check the way how to use it and the problems that could be possible through a actual case. We carry out an experiment to identify the possibility of the fire in the similar condition of the actual fire case. The results of this study are as follows. It is a possible condition to fire if the air blast of the electric radiant heating system is blocked by some combustible materials such as plastic bags continuously. A temperature sensor and a residual current device are necessary to disconnect the power source. It is also necessary to attach a notice in front of the electric radiant hearing system that shows users the fire danger to forbid the possible fire. Fires could be happened by internal defects of the electronic products. However, we can also find many external reasons to happen fires. Therefore, we need to check all reasons to make fires in the scene of a fire.