• Journal of Ocean Engineering and Technology
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• v.24 no.1
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• pp.133-139
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• 2010

From the ancient times, there are waves in the ocean. And all the moving body have energy. We have a kind of hope to convert the wave energy into electric one. Finally we can find out a power generator mechanism that mainly use the principle of pulleys. We have made drawings for this and completed the wave energy converter. This wave energy converter consists of several pulleys, rope, generator, buoys and anchors. The distance between an anchor and buoy is changed according to the hight of waves. Several sets of anchors, pulleys and buoys can make the movement of rope, and the ropes wind up a converter axis. In case of 1 meter movement of the buoy, the winding distance will be amplified 2 or 3 times if we use several moving and fixed pulleys. Based on this concept, we developed 2 kind of prototypes. One is for the test in the laboratory and the other is for the field test. Through the two test, we could confirm the usability of this mechanism.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.357-359
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• 2002

한국전력공사는 합리적인 전력소비를 위해 다양한 요금체계를 제공하고 있다. 그러므로, 주택용과 일반용전력(갑), 일반용전력(을), 교육용전력, 산업용전력(갑), 산업용전력(을) 등 전력사용고객의 성격에 따라 기본요금이나 계절별, 시간대별, 혹은 누진 등 차등요금제를 적용한다. 그러나, 이들 각각에 맞는 전자식 전력량계를 개발한다는 것은 경제성이 없는 일이다. 그러므로, 단일의 전자식 전력량계에서 다양한 요금체계를 수용할 수 있는 방안이 필요하며, 이를 위해 단일의 전자식 전력량계로 공통 기능은 하드웨어로 구현하고 각종 요금체계에 따른 변화를 수용하는 부분은 펌웨어로 개발하여 검침을 수행하는 것이 바람직하다. 본 논문에서는 단일의 전자식 전력량계에서 효과적으로 적용할 수 있도록 한국전력공사에서 시행하고 있는 다양한 요금제도에 부합하는 응용프로그램을 설계하고 구현하는 방안을 제시한다. 또한, 이런 응용 프로그램을 관리하는 소프트웨어를 실제로 구현한 사례를 제시한다.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.95.1-95
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• 2002

<1. New level meter inside the fuel tank> Ultrasound level sensors are widely applied as level meters of liquid tank. Measurement instrument of level between water and fuel is developed. Since the fuel is inflammable, the sensor system doesn't allow to include any electric circuit inside the fuel tank. The optical cable sensor can satisfy this explosive condition. The measurement method with ultrasonic sensor is attached on the tank wall or tank manhole lid. The pressure sensor can't be applied inside the gasoline fuel tank. An ultra-sonic sensor doesn't detect a enough signal reflected from water level deep under gasoline fuel. The pressure sensor is difficult to measure the height o...

• 제어로봇시스템학회:학술대회논문집
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• 1988.10b
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• pp.864-868
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• 1988

During the 1980s, the use of high-speed printing and copying machines which will not tolerate much variation in paper weight has increased. As a result, there is a growing demand for improved basis weight control systems for paper machines. Basis weight, the weight of a square meter sheet of paper, is the most important measure of paper consistency. Until quite recently, basis weight could only be controlled manually; this required experienced operators. The reasons for the difficulty in automating control of basis weight is due to the complexity and variability of process characteristics, the "noisiness" of the process (process disturbances), and actuator inadequacies. This paper describes a method of automatic control that we have developed; it incorporates the experience of expert operators, and the results of simulation, in confidence factors.e factors.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.4
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• pp.318-323
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• 2004

When a strong electric field is applied between a sharply curved electrode and a blunt surface, the corona may result in a gas movement in the electrode gap which is directed toward the blunt surface. That is called the corona wind. It enhances heat and mass transfer between the surface and the surrounding gas. Moreover such enhancement causes no noise or vibration, which can be applied in complex, isolated geometries, and allows simple control of surface temperatures. This paper examines the relationship between the corona wind and the relative humidity. The facility consists of high voltage power supply thin tungsten wire, plate electrode, multimeter, microammeter and flow meter. Gas velocity is a linear function of voltage, relative humidity and is proportional to the square root of the current. The maximum velocities for the positive and negative corona discharge are 1.9 m/s (2.74 CMM/m), 1.5 m/s(2.15 CMM/m), respectively.

• Proceedings of the KIEE Conference
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• 2002.11b
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• pp.343-345
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• 2002

본 논문은 전자식 전럭량계의 전자기적합(EMC)에 대하여 고찰하였다. 전력량계 관련 EMC 요인을 IEC 61000-4 시리즈 규격을 중심으로 고찰하였다. 또한 규격별 EMC 성능평가 항목에 대해서도 비교 검토하였다. 검토결과 국내기준은 국제규격보다 미흡함을 발견하였다. 이들을 바탕으로 국내 규격의 EMC 성능평가 개선방안을 제안하였다. 전자식 전력량계 EMC 개선방안을 연구하는데 기초 자료가 되었으면 한다.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.309-312
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• 2002

Precision stage is essential device for semiconductor equipments, fiber optic assembly systems and micro machines. In this paper, we develop a piezo-electric inchworm type actuator for long stroke ultra precision linear stages, and implement a controller to interface with commercial motion controllers. It provides fast implementation of precise position control system substituting for rotary motor. In the future, using a laser interferometer as a position sensor, we plan to implement a nano meter precision stage.

• Journal of Sensor Science and Technology
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• v.25 no.5
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• pp.337-343
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• 2016

In this paper, we newly introduce a wireless identification system using a solar cell and RF transceivers. The reader sends interrogating signal to a transponder using LED visible light, and the transponder responds to the reader using RF signal. The transponder consists of a solar cell, an amplifier, a microprocessor, and an RF transmitter. The solar cell receives the visible light from the reader and generates current to supply electric power to the other devices in the transponder. At the same time, the solar cell detects interrogating signal in the reader light. The microprocessor senses the interrogating signal and generates a responding signal. The RF transmitter radiates the responding signal to the reader. The transponder is a passive circuit because it operates without external power. In experiments, the maximum read distance between a reader and a transponder was about 1.6 meter.

• Journal of Electrical Engineering and Technology
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• v.7 no.3
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• pp.281-287
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• 2012

The customer load profile clustering method is used to make the TDLP (Typical Daily Load Profile) to estimate the quarter hourly load profile of non-AMR (Automatic Meter Reading) customers. This study examines how the repeated clustering method improves the ability to discriminate among the TDLPs of each cluster. The k-means algorithm is a well-known clustering technology in data mining. Repeated clustering groups the cluster into sub-clusters with the k-means algorithm and chooses the sub-cluster that has the maximum average error and repeats clustering until the final cluster count is satisfied.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.1091-1093
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• 1998

The BESS has a major advantages such as load leveling, quick response emergency power (spinning reserve), frequency and voltage control, improvement of reliability, and deferred generation and transmission capacity construction. However, the economic feasibility of these systems requires justification from the customer side of meter. In this paper, we proposed the economic evaluation model of BESS which is modified and complemented the SYSPLAN model[2]. In addition, we analyzed a economic evaluation from the economic measures such as payback period, overall benefit, ROI, and ROR.