• 한국정보통신학회논문지
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• 제9권2호
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• pp.289-294
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• 2005

본 논문은 변전소내 정보기기에 나타나는 서지전압 전류의 측정 결과에 대해 기술하였다. 서지전압 전류 관측을 위한 전력분석기는 전력용 변압기와 개폐기 주변의 신호선에 설치하였으며, 전력분석기의 시간분해능은 4 MS/s이다. 측정된 서지전압.전류의 크기는 각각 500~1,300v와 500~3,100k 이었으며, 측정기간 동안 평균 5~10회/일 이상의 서지가 기록되었다. 따라서 고전압 전력설비 주변에 설치되는 정보기기는 설치환경에 나타나는 서지의 크기를 고려하여 설계되어야 할 것이다.

• Journal of Electrical Engineering and Technology
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• 제10권3호
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• pp.1107-1113
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• 2015

Test temperature is an important factor affecting the measurement results of dielectric response of field power transformers. In order to better apply the polarization and depolarization current (PDC) to the condition monitoring of oil-paper insulation system in power transformers, the influences and elimination method of test temperature on PDC characteristic spectroscopy (PDC-CS) were investigated. Firstly, the experimental winding sample was measured by PDC method at different test temperatures, then the PDC-CS was obtained from the measurement results and its changing rules were discussed, which show that the PDC-CS appears a horizontal mobility with the rise of temperature. Based on the rules, the “time temperature shift technique” was introduced to eliminate the influence of test temperature. It is shown that the PDC-CS at different test temperatures can be converted to the same reference temperature coincident with each other.

• 대한물리치료과학회지
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• 제21권1호
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• pp.53-58
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• 2014

Background : The purpose of this study is to identify the level of positive influence on the pain and the gripping power in patients with tennis elbow by comparing the TENS treatment method and the kinesio taping therapy with good accessibility among the kinesio taping therapy and electrical therapy. Methods : Targeting the patients diagnosed with tennis elbow, the subjects were categorized in groups of four, each of electrical therapy group and kinesio tape therapy group where the degree of pain reduction through VAS before and after the treatment of each group and the measurement of the degree of gripping power increase using the gripping power measurement tool as well as the pain reduction changes and gripping power increase before and after the treatment between the two groups were compared. Result : As a result, the electrical therapy group and the kinesio tape group were able to obtain the results of pain reduction and gripping power increase through VAS before and after the treatment, but for all pain reduction and gripping power increase, it had no statistically significant changes(p>.05). In addition, in the changes of pain reduction and changes of gripping power increase before and after the treatment, there were no statistically significant differences between the electrical therapy group and the kinesio tape group(p>.05). Conclusion : Based on the results so far, it is thought that the kinesio taping therapy can positively influence the pain reduction of patients with tennis elbow and increase of gripping power.

• KEPCO Journal on Electric Power and Energy
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• 제8권1호
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• pp.31-36
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• 2022

This paper presents the measuring process of dynamic properties of offshore wind power foundation and provides consideration of each step. This Guideline enables to maintain consistent measuring procedure and therefore increase the reliability of test results. Small scaled suction bucket foundation was fabricated to represent the commercial support structure installation mechanism and two cases(free-free, free-fixed) of dynamic tests were performed at workshop. From the tests, the importance of dynamic properties of connection part between suction bucket and tower was figured out. More over, types and configuration of measuring devices are recommended which can help find the natural frequency of wind turbine foundation correctly. In field test, it was found that the natural frequency of suction bucket foundation was increased linearly with the penetration depth due to the confining effect of ambient soil. Meanwhile, it was not easy to get an enough excitation force with normal impact hammer because the N.F of suction bucket model was in the lower range of 0 Hz ~ 5 Hz. Therefore, new excitation method which has enough force and can excite lower frequency range was devised. This study will help develop safety check procedure of suction bucket foundation in field at each installation stage using the N.F measurement.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 추계학술대회 논문집 학회본부
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• pp.239-243
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• 1990

This paper presents a algorithm to improve accuracy and reliability in state estimation of contaminated bad data. The conventional algorithms for detection of bad data confront the problems of excessive memory requirements and long computation time. In order to overcome measurement compensation approach is proposed to reduce computation time and partitioned measurement error model has the advantage of remarkable reduction in computation time and memory requirements in estimated error computation. The proposed algorithm has been tested for IEEE sample systems, which shows its applicability to on-line power systems.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.1727-1732
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• 2004

For the purpose of monitoring by ultrasonic test of the ball bearing conditions in rotating machinery, a system for their diagnosis was developed. ultrasonic technique is used to detect abnormal conditions in the bearing system. And various data such as frequency spectrum, energy and amplitude of ultrasonic signals, and ultrasonic parameters were acquired during experiments with the simulated ball bearing system. Based on the above results and practical application for power plant, algorithms and judgement criteria for diagnosis system was established.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.1415-1419
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• 2004

It is essential to evaluate harmonic characteristics of high speed train using power electronics equipment such as converter-driven motor drives, battery chargers and auxiliary power supplies. The purpose of this study is to measure and analyze harmonics characteristics of korea high speed train prototype. This paper presents result of harmonics measurement and analysis of harmonics characteristics in terms of loading, speed and operation mode.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2003년도 춘계학술발표대회 개요집
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• pp.143-145
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• 2003

The purpose of research is to measure power and dynamic resistance value through RMS module. Specially designed RMS-DC hardware module was tested. Its output which is obtained every half cycle was compared with that of commercial weld checker. The results show good agreement and the relative error in the measurement was found to be around 5%.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 E
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• pp.1776-1778
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• 1998

KEPCO has been constructing the 765 kV double circuit transmission line since 1997. It is worried that the 765 kV transmission lines make TV interference(Ghost and Blocking) due to high tower and multi sub-conductors. This paper presents the mechanism, the measuring method and the results of TV ghost and blocking measurement using a new TV ghost measurement system in a vehicle which was developed by KEPRI.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제9권3호
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• pp.238-243
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• 2009

This paper present same thodology for the classification of power system voltage stability, the trajectory of which to instability is monotonic, using an interior point method based support vector machine(IPMSVM). The SVM based voltage stability classifier canp rovide real-time stability identification only using the local measurement data, without the topological information conventionally used.