• 한국수학교육학회지시리즈B:순수및응용수학
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• 제11권1호
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• pp.1-14
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• 2004

Due to the development of computer network and mobile communications, the security in image data and other related source are very important as in saving or transferring the commercial documents, medical data, and every private picture. Nonetheless, the conventional encryption algorithms are usually focusing on the word message. These methods are too complicated or complex in the respect of image data because they have much more amounts of information to represent. In this sense, we proposed an efficient secret symmetric stream type encryption algorithm which is based on Boolean matrix operation and the characteristic of image data.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.1319-1322
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• 2004

In this paper, a fault diagnosis system for ram in PHWR plant is developed. The developed diagnosis system can detect the ram stuck phenomena due to increased ball wear and damage in ball nut using discrete wavelet transform before the ram is stuck. The validity of developed diagnosis system is shown via experiments using ball nut characteristic test equipment.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.300-302
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• 2003

Fluorescent lamp converts electrical energy Into light energy. Generally we use both electronic ballast and glow starter method in the house. We developed 40W electronic starter and its characteristic is verified by experiments. The efficiency of ballast is improved by using the LC Parallel reasonance circuit at input stage and LC series reasonance circuit at out-put stage.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(2)
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• pp.910-913
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• 2004

This paper is about to develop a system to monitor speed droop rate characteristic of turbine governor for electric power plant. High quality electricity can be obtained, and so electricity supplier get more profit through it. Developed system presents basis of judgement of unusual system and proper maintenance time for the governor and power plant.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.798-801
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• 2001

we have investigated a characteristic of a vibration displacement detector, which was made with a photocoupler. Output signals of the detector were dominant at 700Hz of the frequency of vibrator, and It was maximum, when the amplitude of input signal had been at 1.1V. The detector will be used in measuring the surface roughness of substrates.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2058-2062
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• 2005

This article describes the useful way to measure the torque and RPM of the geared motor. For this, we have made the planetary geared reduction motor including the torque sensor unit which consists of hall effects sensor and permanent magnet. Our monitoring system displays the sensing values (torque, rpm) and the calculated value (power) and it also has the network capability using the Bluetooth protocol. We will show that our solution is much more inexpensive and simple method to measure torque and rpm than before.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.457-460
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• 2003

This paper discusses laboratory evaluations to assess the physical properties of antiwashout underwater concrete (AWC) containing pozzolanic materials such as fly ash (FA), blast furnace slag (SG) and metakaolin(MK). For the experiments, pH value, suspended solids, slump flow, efflux time and compressive strength were tested. According to the results from compressive strength test, MK10 showed the very high compressive strength characteristic during the entire curing days, but the rate of strength development was decreased as time goes by.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 전문대학교육위원
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• pp.30-32
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• 2004

In this paper, as the preceding research for development of Intelligent Electronic Device(IED) for digital based substation automation system(SAS), we tried to selection of the most suitable digital filter by comparison of frequency response characteristic. performance of wanted frequency component extraction.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 후기학술대회논문집
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• pp.63-64
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• 2005

This paper proposed a miniaturization passive element employing the multiple microstrip line. As a result of this method, we realized the transmission line miniaturized. The applying structure designed and evaluated a power divider on GaAS MMIC circuit. It draws a plan in a center Frequency as the observation could do good characteristic.

• 산업경영시스템학회지
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• 제15권26호
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• pp.1-11
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• 1992

Material Handling equipments such as hoists, cranes, storage and retrieval machines, gantry robots and conveyors are carrying out more important tasks in material flow automation field. This paper is concerned with the characteristic and the position of this industry, and presents the status of the business world scale, supply and demmand. import and export transition, and directing posts of the profits. Also it gives productivity security and activity.