• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1023-1024
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• 2008

The road surface scripture season must be interpreted with hitherto whole aspect line scripture season different. TRAM (street cars) it respects an operation it stands and back must be operated the bus which runs place and riding grade different public transportation means and to be mixed. With the numerous crossroads zebra crossing and the coat platform must operate back. The role of the operation article most is important. It undergoes the influence of traffic signal specially directly. It considers each facility etc. of the road and must construct a proper equipment in him with connection method of the signal system which it follows in the middle urethra. Must secure the fixed time characteristic of the operation which road surface scripture season is efficient and expression speed and operation. In order the [le] according to interface plan with traffic signal it does to consider a traffic signal first of all. This the research of operation provision is necessary.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.131-134
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• 1997

McT는 MOS-게이트형 사이리스터로써 MOS-게이트형 턴-온 및 턴-오프 특성과 낮은 도통 전압을 나타내는 소자이다. 그러나 SOA(Safe Operation Area)가 상대적으로 작기 때문에 스너버 회로를 필요로 한다. 본 논문에서는 간단한 MCT PSPICE 모델을 사용하여 스위칭 특성과 RCD 스너버의 특성을 분석하였고 스너버 회로 설계방식을 제안하였다.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.4
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• pp.427-431
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• 2009

In this study, the dynamic characteristic of a contact wire and pantograph suppling electrical power to high-speed trains are investigated from an electrical response point of view. To analysis power line disturbance by induced contact loss phenomenon for high speed operation, a hardware Simulator which considered contact loss between contact wire and the pantograph as well as contact wire deviation is developed. It is confirmed that a contact wire and pantograph model are necessary for studying the dynamic behavior of the pantograph system. One of the most important needs accompanied by increasing the speed of high-speed train is reduced that an arc phenomenon by loss of contact brings out EMI. In case of a high-speed train using electrical power, as comparison with diesel rolling stock, PLD(Power Line Disturbance) such as harmonic, transient voltage and current, EMI(Electromagnetic Interference), dummy signal injection etc usually occurs. Throughout experiment, it is verified that an arc phenomenon is brought out for simulator operation and consequently conducted noise is flowed in electric circuit by power line disturbance.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1450-1454
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• 1996

Even though digital control type high speed solenoid valve is a little inferior to analog control type servo valve and proportional control valve in performance, it is cheap and has secure performance against pollutant and simple control circuit. But high speed solenoid valve is hardly used for heavy machinery instead of servo valve or proportional control valve that is used in severe condition because the valve itself is small capacity and it shows wide dead zone during on-off control and chattering of hydraulic cylinder by chattering of pressure. It is desirable to use low-priced and strong pollutant resistant high speed solenoid valve for obtaining reliability of operation from severe working condition because it isn't necessary to acquire response characteristic of high frequency when we consider the characteristic of heavy machinery operation. In this study, PWM control algorithm for pilot pressure control of large capacity pilot operating valve will be used for precision position control of heavy machinery hydraulic cylinder. Not only cost reduction of main control valve but also high reliability of heavy machinery in severe condition can be obtained by using this pilot operating spool valve with high speed solenoid valve.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.3
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• pp.244-249
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• 2008

This paper deals with speed control of DC servo motor using a Fuzzy tuning observer. Speed sensor detect a speed of rotor continuously. But it have a limit as a driving speed to detect speed precisely. So it is problem to improve the performance of the driving system. To solve the problem, it is studied to detect a speed of DC motor without sensor. In particular, study on the method to estimate the speed using the observer is performed a lot. In this parer, the gain of the observer is properly set up using the fuzzy observer. The fuzzy observer has a superior transient characteristic and is easy to implement compared the existing method is designed. It estimate the derivative of the armature current directly using the armature current measured in the DC motor. It estimate the speed of the rotor using the differentiation. It is proposed speed sensorless control method using the estimated speed. Optimal gain of Luenberger observer is set up using the fuzzy observer and adapted speed control of DC servo motor low speed operation. It is proved excellence and feasibility of the presented observer from the comparison tested a case with a speed sensor and a case without a speed sensor which used a highly efficient drive and 200W DC servo motor starting system.

• Journal of the Korean Society of Safety
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• v.21 no.5 s.77
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• pp.40-45
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• 2006

In the operation of large capacity hydro generators, it's a very important thing that to minimize several kind of electrical trouble and accident. In order to overcome these problems, the on-line and off-line partial discharge (PD) measuring method has become an important one. Nowadays, epoxy mica coupler(EMC) has been the most widely used sensors for on-line PD detection in rotating machines. This time, we have made a ceramic coupling sensor using $SrTiO_{3}$, because at present, most of sensors has high cost and difficult procedure to making. This paper deals with the electrical characteristics of a ceramic coupling sensor, which has been made to continuously measure PD activity during the operation condition for 13kV class hydro generator. And we have performed the evaluation of sensor life and reliability based on the characteristic testing. The experimental results confirm that the sensor has satisfied at electrical required performance and output characteristic for simulated input signal.

• The Transactions of the Korean Institute of Power Electronics
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• v.3 no.1
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• pp.53-60
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• 1998

In this paper, the principle of operation, the part characteristic, characteristic of component movement, analysis are carried out for camcoder iris assembly which is one of the important element component in Video camera large projection TV instrument. And some Know-how for development of element component is also included. The magnetic field circuit for the small and simple structure with low power consumption is introduced and new materials of yoke for small motor system is suggested. Especially, the relation with remained magnetic field and operation duration time is analyzed by experimental results. Some problems of nonlinear torque characteristics included in this system is considered to obtain the simple and low cost structure in domestic production. Furthermore, development procedure is suggested for iris assembly and some methods to reduce the burr with some check points for small precise accessories are explained.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.964-968
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• 2005

The standardization of information communication is doing a Internal each other connection and each other characteristic stability operation security in objective. From the low-speed network of the subway operation beginning currently it changes with the superhigh speed digital information transmission communication service environment which is a quality service, the hazard which plans the quality improvement of the efficient communication service use which hits to here and passenger service the standardization of the technical standard which stands and the improvement which hits to an engineering standard and facility must come to accomplish. The facility which existing is been old or the enclosure communication equipments which are insufficient. it improves, establishment itexpands efficiently, like this facilities it is stabilized and it is economic and rationally use maintenance it manages with the plan for the inside and outside of the country information communication relation technical standard and engineering standard service feature improvement and future expandability and economical efficiency, the possibility of having a pliability in order to be, rational technical standard and standard it takes a triangular position, efficient characteristic security of information communication service there is a place objective which promises the rational development of course city railroad communication system with character. Function improvement of enclosure communication base equipment, against an improvement and standardization plan it described trom the prosecution which it sees.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.9
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• pp.1380-1386
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• 2012

It is important to consider supply voltage stability in case of design and construction of a substation at electric railway because a urban transit is operated by electricity and it is driven simultaneous in the same section. This paper study on variation of the dynamic characteristic of supply voltage according to the track environment and spatial distribution as driving of urban transits. Simulation tool, TOM(Train Operations Model) software is used to ensure stability of feeder system being used around the world. As results of simulation, voltage of the contact wire is in limits on driving operation diagram of urban transits. Also, it has confirmed that there is a correlation the phase current, depending on the speed of urban transit and track environment like vertical gradients and curve radius.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.367-367
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• 2019

최근 기후변화로 인해 국지성 호우 및 태풍의 빈도가 빈발하고 및 규모가 커지고 있으며 그로 인한 홍수피해규모는 증가하고 있다. 본 논문에서는 도시 지역의 호우로 인한 침수유발 강우량을 산정하는 기법의 정확도를 산정하는데 목적이 있으며 이를 위해 ROC(Receiver Operation Characteristic Curve) 분석을 이용하였다. 본 논문에서는 분포형 홍수해석 모형인 S-RAT 모형과 2차원 침수해석 모형 FLO-2D을 커플링하여 호우로 인한 침수해석을 실시하였으며 강우시나리오는 설계 강우 200mm의 강우를 10% 간격으로 증가시켜 강우량 대비 침수심 자료를 모의하였다. 모의한 침수심 자료를 이용하여 유역 격자를 $1km{\times}1km$ 별 강우량-침수심 관계곡선식을 제시하였으며 개발된 곡선식을 이용하여 특정 침수심(20cm)을 유발시키는 강우량(한계강우량)을 산정하였다. 정확도 산정은 ROC(Receiver Operation Characteristic Curve) 분석 방법을 이용하여 침수 유무의 적중률에 따른 민감도와 특이도를 이용하여 AUC(Area Under the Curve)의 점수로 정확도를 판단하였다. 본 논문에서는 본 논문에서 제시한 한계강우량의 정확도를 판단하기 위하여 2011년 7월의 사당역 일대 침수사례를 이용하였다. 실제 침수정보가 없어 실제 호우사상과 실제 하수관망을 고려할 수 있는 SWMM 모형을 이용하여 침수분석을 실시하였다. 분석 결과 평균 ROC는 약 0.7로 나타났으며 5 단계의 구분에서 Fair 단계로 적정 수준의 정확도를 확보한 것으로 나타났다.