• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.82-82
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• 2009

현재 국내에는 많은 가구들이 전기를 사용하고 있다. 아파트, 주택에 들어가는 전기 시스템들이 많이 발전하였지만 뜻하지 않은 사고로 인해 정전이 되는 경우가 있다. 정전시에는 아파트 같은 경우는 비상등, 엘리베이터 등 최소한의 장치만이 작동하도록 되어있다. 그러므로 각 세대에는 전기가 들어가지 않는다. 우리나라 경우에는 태풍이나 여름 같은 경우에는 전기를 많이 사용하기 때문에 발전기가 과부화 걸리는 현상이 생기기도 한다. 장기간 정전시에 가장 문제가 되는 기기는 냉장고, 전등이 될 것이다. 냉장고 같은 경우는 음식들이 상하게 되고, 전등 같은 경우에는 밤에 활동하는데 지장을 주게 된다. 따라서 본 논문에서는 정전시에는 자동적으로 비상발전기의 전원을 사용하고, 상시에는 다시 한전의 전원을 사용하게 하는 초소형 자동 스위칭 전원 모듈을 설계 제작한 논문이다. 설계된 스위칭 모듈에 대해서 시뮬레이션한 결과 예상한대로 비상시에 자동적으로 스위칭되는 결과를 알 수 있었다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.11a
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• pp.423-426
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• 2005

In this paper, we proposed a PID tuning algorithm by the fuzzy set theory to improve the performance of the PID controller. The new tuning algorithm for the PID controller has the initial value of parameter Kp, $\tau_{I}$, $\tau_{D}$. by the Ziegler-Nichols formula that uses the ultimate gain and ultimate period from a relay tuning experiment. We will get the error and the error rate of plant output corresponding to the initial value of parameter and fnd the new proportion gain(Kp) and the integral time ($\tau_{I}$) from fuzzy tuner by the error and error rate of plant oueut as a membership function of fuzzy theory. This fuzzy auto tuning algorithm for PID controller considerably reduced the overshoot and rise time as compared to any other PID controller tuning algorithms. And in real parametric uncertainty systems, it constitutes an appreciable improvement of performance. The significant property of this algorithm is shown by simulation

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.2
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• pp.92-99
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• 2014

The paper is related to smart maximum power system based on program logic. Especially, this system compares the total demand power with the target power by using the signal from the digital kilo watt meter. Based on the power information by the maximum power control equipment the consumed future power is anticipated. In addition, through consumed future power the controllable target power is set, and it applies on the maximum power control equipment. User or manager would control the load efficiently through the simple programming which could control load based on the control sequence and relay. To begin with the conventional maximum power control algorithm is surveyed, and the smart maximum power control system based on program logic is used, and the new algorithm from full load to proportion shut down is proposed by using PLC program. the validity of the proposed control scheme is investigated by both simulation results.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.1107-1112
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• 2002

An easy elevator originated is an opened system to compare an existing equipment, and learning efficient is high as a wiring that the sequence control circuit is on and off. The structure of an equipment to be controled from the first floor to the fifth floor is constructed by a lamp to express the function of the open-close of the door according to the cage moving, to express the mechanical actuation of the forward-reverse break and motor of load and of hand-worked control component of Push-Button S/W, L/S and Relay. In order to act of the elevator function that these components connected, designed the auto program and the sequence control circuit. Consequently the process that these(1~5steps) operated the cage with an auto program of the elevator and the sequence control circuit is controled by the step of forward and reverse that the L/S1~L/S5 of sensor adjust function let posit, by the adjustable S/W1~S/W5 of PLC testing panel and the S/W1~S/W5 which installed on the transparent acryl plate of a frame. In here, improved apparatus is the learning equipment of combined use to study the principle and the technique of the originated sequence control circuit and the auto program of PLC.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.6
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• pp.915-920
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• 2011

P2P technology is the concept to share resources efficiently in distributed environments that a lot of research is underway. a lot. In these P2P systems, the server to support the contents-information have less overloads than the composed system as the server to have resources generally. In this paper, we suggest a P2P system to support conveniences to choice time for users that were connected with the information of joint-buying based on social network. Social networks based on co-purchasing information and price alerts using the P2P system is provided by the peer, this relay information is provided by the P2P server.

• The Journal of the Korea institute of electronic communication sciences
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• v.3 no.4
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• pp.282-288
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• 2008

In this paper, the Passive Intermodulation Distortion(PIMD) of high power RF Filter is measured with filter inner coating materials and we suggest how to reduced the PIMD of RF filter coating methods. According to the standard measurement regulation by IEC, the Passive Intermodulation Distortion of Wibro relay high power filter are measured. We suggest the coating materials and coating methods of high power filter inner structure to reduce the PIMD generating by insert loss and worse flatness of filter delay in the design of Wibro high power filter efficiently.

• Journal of the Korean Data and Information Science Society
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• v.22 no.4
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• pp.735-740
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• 2011

In recent, electronic devices were able to develop and focus for ultra-compact size, intelligence, multifunction and broadband. Their SMPS is realized to ultra-compact size, light weight, high efficiency, high reliability, low noises. The power module which can be used to supply DC output from a commercial power supply (85 to 265 VAC). A switching power supply can be made easily by adding simply external circuit, such as microcontroller, a relay, etc. It would be apply to mostly electronic devices, and fit the global project "Saving energy". But we need to statistical analysis for a quality and performance about a load and an output voltage in product.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.12
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• pp.1964-1969
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• 2012

This paper presents to verify the selective grounding fault protective relaying technique for the ungrounded DC traction power supply system. This system selectively blocks fault section when grounding fault occurred. In order to perform this verification, field test facilities have been installed on Oesam substation and Worldcup-Stadium substation, and field test process has been suggested. Also, selective grounding fault protective relaying components and rail voltage reduction device have been tested with the various trial examinations. In order to compare and evaluate performance of the selective grounding fault protective relaying function, field test system was modeled and the system fault simulation results were compared and evaluated with the field test result. Performance of selective grounding fault protective relaying function was evaluated with the above-mentioned process, and the fact that the system recognizes fault section irrespective of insulation between rail and ground and fault resistance from grounding fault.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.4
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• pp.351-357
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• 2003

An easy learning elevator originated is opened to compare the existed teaming equipment, and it had a high studied efficiency that the sequence control circuit can open and close with the wire. The structure of equipment to be controlled from the first floor to the fifth floors is demostrated by the constructive apparatus with the lamps to express the function of the open-close of the door according to the cage moving with a mechanical actuation of the forward reverse breaker and the motor of load, and the mechanical actuation of hand-operation control components of push-button S/W and L/S and relay etc. These components let connect each other in order to control of the elevator function with the auto program and the designed sequence control circuit. Consequently the cage could go and come till 1∼5 steps with an auto program of the elevator and the sequence control circuit. The sequence control circuit is controlled by the step of forward and reverse to follow as that the sensor function of L/S1 ∼ L/S5 let posit with the control switchs of S/W1 ∼ S/W5 of PLC testing panel and switchs of S/W1 ∼ S/W5 installed on the transparent acryl plate of the frame. In here, improved apparatus is the hand-auto operation combined learning equipment to study the principle and technique of the originate sequence control circuit and the auto program of PLC.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.683-686
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• 2000

The chargers for DC power supply of the contro1lers, which have been installed in the relay rooms in 345/154kV substations of KEPCO, lag in both aspects of technique and performance. Moreover, as they are SCR-based, they dont meet the performance requirements of todays digital and automated controllers. Now two controllers are running in pair and one of those is for reservation. There are lots of troubles because the patrol engineering team has to replace them manually whenever they are out of order. So it is expected to bring convenience if the charger replacement is automated. Also, the existing chargers take much space, weight and cost - which have increased the need of development to make them smaller, less expensive, and have high quality. We will develop a charger system which has one fifth of the weight of the existing system by double-integrating the volume. The new system will be ready for a future full unmanned system with integrated pores for remote control, state-of-the-art digital features, and more than 90% efficiency/power factor against 80% efficiency/power factor of the existing system.