• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 1999년도 학술대회논문집-국제 전기방전 및 플라즈마 심포지엄 Proceedings of 1999 KIIEE Annual Conference-International Symposium of Electrical Discharge and Plasma
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• pp.285-289
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• 1999

Insulation diagnosis techniques of power equipments for the stable power supply and prevention from accidents are of high importance. Diagnosis techniques is able to prevent from large accidents before they happen by finding signs of the accidents. From this point of view, this paper simulated discharge progress and partial discharge using needle-plan electrode system in air, studied the distribution of frequency spectrum of the radiated electromagnetic waves using biconical antenna and spectrum analyzer. From results of this study, the new method was introduced for measurement and analyzation of the radiated electromagnetic waves in accordance with discharge progress in air, Besides, according to the consideration of the mutual relation between frequency spectrum of the radiated electromagnetic waves and discharge progress, it was confirmed that detecting partial discharge and estimating discharge progress were possible.

• 조명전기설비학회논문지
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• 제17권2호
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• pp.81-87
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• 2003

본 논문은 공기중 침대 평판 전극계를 이용하여 방전진전 과정과 부분방전을 모의하였다. 이 때 방전진전과정에 따른 방사전자파를 biconical 안테나와 스펙트럼 분석기를 이용하여 주파수 스펙트럼 분포를 분석 연구하였다. 본 연구의 결과로부터 공기중 교류방전 진전에 따른 방사전자파의 측정과 분석에 의한 절연진단을 위한 방법을 제시하였고 또한 방전진전과정과 방사전자파를 상호관계를 고려하면 부분방전의 검출과 방전진전과정의 평가가 가능함을 확인하였다

• Progress in Superconductivity
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• 제12권2호
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• pp.124-128
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• 2011

We have developed a high-$T_C$ SQUID magnetometer system to measure magnetocardiograms of laboratory rats. White noise of the measurement system was about 50 fT/$Hz^{1/2}$ when measured in a magnetically shielded box. We optimized the measurement position to obtain clear MCG wave from rat's small heart by using grid measurements. With the optimization, the MCG signal was successfully detected with the peak amplitude of about 50 pT. We could observe well defined P-, QRS-, and T-wave from the rat MCG. The results suggest that the developed system has a strong potential to monitor the progress of heart disease model using laboratory rat.

• 오토저널
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• 제10권3호
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• pp.45-50
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• 1988

The measurement system of the pressure in engine cylinder is developed with the aids of the microcomputer, A/D converter and simple electrical circuits. The experiment is performed in 4 cycle single cylinder Gasoline engine. When data for the pressure progress is sampled, clock signal or signal from the crank angle is used as trigger. The variation of the pressure during the cycles can be well obtained experimentally. So, the informations which are necessary in the combustion analysis, i.e. expansion pressure, indicated mean effective pressure, the magnitude and time of the maximum pressure ignition time, the rate of pressure rise and heat release and combustion rates can be obtained by the calculation using experimental data. Also, the informations about the after-burning process, the existence of the detonation waves and end time of combustion can be investigated from this study.

• 한국초전도ㆍ저온공학회논문지
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• 제16권4호
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• pp.1-6
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• 2014

Superconducting quantum interference device (SQUID) is a sensitive detector of magnetic flux signals. Up to now, the main application of SQUIDs has been measurements of magnetic flux signals in the frequency range from near DC to several MHz. Recently, cryogenic low-noise radio-frequency (RF) amplifiers based on DC SQUID are under development aiming to detect RF signals with sensitivity approaching quantum limit. In this paper, we review the recent progress of cryogenic low-noise RF amplifiers based on SQUID technology.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.121.5-121
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• 2001

For the last decade, remarkable progress in the coating weight uniformity of hot dip galvanized product has been made to overcome the tightening quality constraints and produce cost-effective galvanized products. This progress results from research and development works for more efficient air knife, more accurate model of coating process, more precise measurement of coating weight and more efficient control logics. The activities for an efficient mathematical model to predict coating weight and several control logics which has been implemented on the No.1 CGL, No. 2 CGL, and PGL at KwangYang Steel Works are reviewed in this article.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 C
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• pp.1747-1749
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• 2001

This paper simulated discharge progress and partial discharge using needle-plan electrodes system in $SF_6$, studied the distribution of frequency spectrum of the radiated electromagnetic waves using biconical antenna and spectrum analyzer. From results of this study, a method was introduced for measurement and analysis of the radiated electromagnetic waves in accordance with discharge progress in $SF_6$. Besides, according to the consideration of the mutual relation between frequency spectrum of the radiated electromagnetic waves and discharge progress, it was confirmed that detecting partial discharge and estimating discharge progress in $SF_6$ can be possible.

• 한국초전도ㆍ저온공학회논문지
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• 제15권2호
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• pp.48-51
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• 2013

The thermal contact resistance (TCR) is one of the important components in the cryogenic systems. Especially, cryogenic measurement devices using a cryocooler can be affected by TCR because the systems have to consist of several metal components in contact with each other for heat transferring to the specimen without cryogen. Therefore, accurate measurement and understanding of TCR is necessary for the design of cryogenic measurement device using a cryocooler. The TCR occurs at the interface between metals and it can be affected by variable factors, such as roughness of metal surface, contact area and contact pressure. In this study, we designed TCR measurement system at various temperatures using a cryocooler as a heat sink and used steady state method to measure the TCR between metals. The copper is selected as a specimen in the experiment because it is widely used as a heat transfer medium in the cryogenic measurement devices. The TCR between Cu and Cu is measured for various temperatures and contact pressures. The effect of the interfacial materials on the TCR is also investigated.

• 한국의류산업학회지
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• 제14권3호
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• pp.448-453
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• 2012

This study aims to categorize age groups for shoes manufacturing including shoes size and boot tree development for Koreans. In order to carry out the research, the characteristics of different parts of foot in relation to size are analyzed according to age and sex, making use of human body measurement database. As a result of statistical analysis, it was found that the measurement items such as foot length, metatarsal tibiale, foot breadth and instep circumference of a person reached the range of standard deviation and average numerical figures of an adult group (18-24) from the age of 14 in men's case, and from 12 for women's case, which indicates the time of completion of their foot growth. Based on these findings where males of 14 years old and females of 12 are within similar measurement range to adults, it is necessary to categorize the age groups for shoe sizing system into the following four groups: males 13 years old or under, males 14 years old or over, females 11 years or under, and females 12 years or over. The proportional measurement produced by dividing each measurement item of foot parts by foot length was compared in an independent samples t-test, and there were meaningful differences according to different foot shapes of the two age groups of males 13 or under - males 14 or over, and females 11 or under - females 12 or over. Also, the independent samples t-test for the age groups of males 13 or under - females 11 or under, and males 14 or over - female 12 or over, showed similar meaningful differences, which indicates the differences in foot shapes of male and female during the period of growth.

• Smart Structures and Systems
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• 제30권3호
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• pp.287-301
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• 2022

The machine-vision based structural displacement measurement methods are widely used due to its flexible deployment and non-contact measurement characteristics. The accuracy of vision measurement is directly related to the image resolution. In the field of computer vision, super-resolution reconstruction is an emerging method to improve image resolution. Particularly, the deep-learning based image super-resolution methods have shown great potential for improving image resolution and thus the machine-vision based measurement. In this article, we firstly review the latest progress of several deep learning based super-resolution models, together with the public benchmark datasets and the performance evaluation index. Secondly, we construct a binocular visual measurement platform to measure the distances of the adjacent corners on a chessboard that is universally used as a target when measuring the structure displacement via machine-vision based approaches. And then, several typical deep learning based super resolution algorithms are employed to improve the visual measurement performance. Experimental results show that super-resolution reconstruction technology can improve the accuracy of distance measurement of adjacent corners. According to the experimental results, one can find that the measurement accuracy improvement of the super resolution algorithms is not consistent with the existing quantitative performance evaluation index. Lastly, the current challenges and future trends of super resolution algorithms for visual measurement applications are pointed out.