• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1783-1784
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• 2006

A laser interferometer is the unique measurement device that can measure the range up to a few meters with sub-nano resolution and this characteristic makes it as the important sensing device for the emerging nano-mechatronics technologies. The laser interferometer, however, is very sensitive to the environments such as temperature, humidity, sound noises, vibrations and air turbulences and these factors result in a few hundred nano meter errors. There have been many efforts to reduce these environmental errors. The output of the laser interferometer is assumed to be the sum of a real displacement and a Markov process noise. The purpose of this paper is to develop Kalman filter algorithms to reduce the laser interferometer measurement errors by exploiting the information of displacements in position-servo systems.

• 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 Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.593-595
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• 2011

본 논문에서는 기존에 전력소비자들의 전기요금을 낮추기 위해 전력사업자가 설치하는 스마트미터(smart meter)에 의존하는 대신 가정 내 PLC(Power Line Communication)망을 활용하여 소비자의 기기별로 에너지모니터링 환경을 구축하여 스마트그리드를 통해 소비자가 얻을 수 있는 많은 혜택을 제공할 수 있는 스마트플러그 기반 AMI 시스템을 개발하고자 한다.

• 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.

• Journal of The Korean Astronomical Society
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• v.29 no.spc1
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• pp.279-280
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• 1996

This paper reports on the outline and the status of the TAMA-300 project, the 300 meter laser interferometer gravitational wave detector developed by a team of scientists of several research institutes and universities in Japan. In fact the project has been funded and its construction started at the National Astronomical Observatory, Mitaka, in spring 1995. And the constructions of the tunnels for the east-west and north-south arms and of the central building are completed and a half of pipes for laser beams were brought in. Very stable laser oscillator has been almost completed and mew techniques such as vibration isolations, recycling of laser power, and suspension of mirrors by double pendulums have been developed. In fact the purposes of the project are to establish techniques necessary for future km-class detectors and to operate the detector to catch possible gravitational wave events in nearby galaxies such as Andromeda, the target sensitivity being $3 {\times} 10^{-21}$ at 300Hz.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1332-1335
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• 2003

This paper presents the enhancement of oxygen transfer efficiency using the vibrating intravascular lung assist device (VIVLAD) in in-vitro experiments for patients having chronic respiratory problems. The test section was a cylinder duct with the inner diameter of 30 mm. The flow rate was controlled by the pump and monitored by a built-in flow meter. The vibration apparatus was composed of a piezo-vibrator, a function generator. and a power amplifier. The direction of vibration was radial to the fluid flow. Gas flow rates of up to 6 l/min through the 120-cm-Jong hollow fibers have been achieved by exciting a piezo-vibrator. The output of PVDF sensor were investigated by various frequencies in VIVLAD. The experimental results showed that VIVLAD would be enhance oxygen transfer efficiency.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.11
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• pp.1123-1128
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• 2004

An experimental study on firing noise of K2 rifle was performed. Firing noises of K2 rifle were measured at close distance to rifle. Firing noise of K2 rifle which made in Korea, has not measured before. The measurement of firing noise at close distance is not simple, because the amplitude of firing noise is much bigger than the measuring limit of ordinary sound level meter even though it uses a signal attenuator. The measurement of firing noise at close distance is necessary for noise source positioning and for obtaining the sound power of K2 rifle. By this experimental study, the firing noise levels of K2 rifle at different positions are obtained and these data can be used to Predict the sound pressure level at any distance from muzzle of the rifle. Also these data can be used to calculate the threshold shift of gunner's ear.

• YAKHAK HOEJI
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• v.35 no.4
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• pp.277-282
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• 1991

Rheological, colloidal and micromeritical properties were followed to investigate aging mechanisms of hydrous aluminum oxide suspension using Zeta-meter systems, BET adsorption apparatus, Master sizer and electronmicroscope. The results indicate that hydrous aluminum oxide suspension revealed plastic flow with thixotropy. The viscosity, thixotropy and yield value were increased with increasing concentration. During aging process, the viscosity and thixotropic index were increased by an addition of glycerin, however, sorbitol stabilized aging process of the suspension being accompanied with growth of particle size and reduction in specific surface area, pore area and pore volume, and consistency. Diminution of adsorptive power of the particles was also protected by addition of sorbitol to hydrous aluminum oxide suspension. From these results, one of aging mechanism of hydrous aluminum oxide suspension assumed growth and/or crystallization of colloidal particles in aqueous suspension.

• 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 Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1767-1771
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• 2000

We report the number of calibration and test for acoustic field which were conducted in KRISS between the year of 1990 and 1999. The items contain sound level meter and calibrator for calibration and sound absorption coefficient, transmission loss, sound pressure level of siren, sound pressure level and power of acoustic instrument and relative accessories for test. The data show that the number of them have been increased continuously.