• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.1100-1103
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• 2004

The paper presents the results of using the fundamental and the low frequency harmonic components of leakage current to study aging of EPDM insulator for contaminated condition by kaolin. The largeer the leakage current during 200ms, the higher harmonic component at 60hz. The harmonic component at 60hz and the odd order harmonics is increase relation without Kaolin Conent. Arcing on the surface was always associated with distortion in the leakage current; hence the low frequency components of the leakage currnent can be used as a means to evaluate the surface degration. Both the fundamental and 3rd & 5th harmonics increase dry-band activity.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.5
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• pp.21-32
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• 2010

60 Hz 자기장에서 예쁜꼬마선충(C. elegans)의 발생 및 생식에 미치는 영향을 조사하였다. 자기장 노출 조건은 $0{\sim}500\;{\mu}T$이며, 실험 온도는 선충의 일반적 배양 온도 범위($2 1.2{\pm}0.6^{\circ}C$)에서 일정하게 유지하였으며, 노출은 선충의 배양 기간 동안 지속되었다. C. elegas 야생형 N2 및 스트레스에 민감한 hsf-1와 crt-1 등의 돌연변이체들에서 실험에 사용한 노출 조건에 따른 생식력의 차이는 없었다. 여러 세대에 걸쳐 자기장에 노출한 경우에도 자기장에 의한 생식력의 변화는 없었다. 결론적으로, C. elegans는 크기가 매우 작으므로(길이 약 1 mm) 유도전류가 적게 발생하여, 자기장($-500\;{\mu}T$)에 의한 영향이 없는 것으로 사려된다.

• Journal of Korean Ophthalmic Optics Society
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• v.6 no.1
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• pp.87-91
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• 2001

The a-C:H films have been grown on the glass substrate by PECVD method, where plasma was generated with a 60 Hz line power source. The carbonization is checked from peak intensities of D($sp^3$) and G($sp^2$) peaks in Raman spectra and is analyzed using the Gaussian convolution method of spectrum. Both the bonding strength of C-H and the ratio of $sp^3$ to $sp^2$ in bonding are found to be slightly dependent of partial pressure of $C_2H_2$.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.04a
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• pp.253-254
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• 2002

현대 생활에 있어서 필요불가결 한 요소인 전기와 각종 전자기기의 괄목할 만한 사용 증가로 인하여 생활환경에서의 업체의 관련직종 뿐만 아니라 일반인도 생활 속에서 전자파에 노출될 기회가 증대되고 있다 전자파의 인체영향에 관한 연구는 1979년 어린이 백혈병 발생과 전자파 노출과의 연관성에 관한 역학적 연구 결과가 발표된 이후 각종 질환과의 관련성에 때한 논란이 끊임없이 계속되고 있다. 따라서 본 연구는 생활 속에 많이 사용되는 가전제품 및 사무용 전자기기로부터의 전자파 방출 수준 정도를 파악하여 전자파 관련 연구의 과학적인 기초자료를 제공하는데 그 목적이 있다. (중략)

• The Transactions of the Korean Institute of Electrical Engineers
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• v.35 no.4
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• pp.127-135
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• 1986

This paper represents a real time algorithm which improves the some drawbacks in the past methods for detection of the QRS conplexes of ECG signals. In the conventional method we can't detect QRS complex and QRS duration more correctly in case of (1) the contaminated ECG with 60Hz noise, muscle noise. (2) the movement of the baseline for a QRS complex. (3) being abnormal QRS complex with prolonging QRS. Therefore, we have proposed a new algorithm which can detect accurate QRS complex detection in case of the contaminated ECG with 60Hz noise, muscle noise, and movement of baseline for QRS complex. Moreover, in case of prolonging QRS we accomplished to detect not only QRS complex but also a single pulse that has a width proportional to QRS duration. This algorithm which is proposed in our paper in our paper in programmed with 6502 assembly language for real time ECG signal processing.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.467-469
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• 2001

An investigation into power conditioners that interface with photovoltaic array and utilities has been completed. The rating for this investigation is residential system(3-5kW) that interface with a 220V single phase utility connection. As the result of this investigation, a 3kW high frequency PWM IGBT inverter feeding a high frequency isolation transformer with a sinusoidal current wave was selected. The output of the transformer rectified with a diode bridge rectifier, four IGBT, used as 60Hz switched, reverse the polarity of the rectified current on every other half cycle of the utility voltage. Even though the high frequency link system used more power semiconductors, a net size, weight, and parts cost saving result compared to the other systems due to elimination of 60Hz transformer.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.3
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• pp.432-436
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• 1994

The aging characteristics of amorphous FeS178TBS113TSiS19T wound cores have been investigated as a function of aging temperature and time. The core losses(1.2T/60Hz) of amorphous wound cores dipped in transformer oil decrease in comparision with initial stage of aging test due to insulation of ribbon stacks by oil penetration. It is estimated that it takes 30 years or more for 10% increase in core losses (1.2T/60Hz) of amorphous wound cores aged at normal transformer running temperature(100$^{\circ}C$). So we condlude that the amorphous core is satisfactorily applicable to transformer.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1050-1052
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• 2000

An investigation into power conditioners that interface with photovoltaic array and utilities has been completed. The rating for this investigation is residential system (3-5kW) that interface with a 220V single phase utility connection. As the result of this investigation. a 3kW high frequency PWM IGBT inverter feeding a high frequency isolation transformer with a sinusoidal current wave was selected. The output of the transformer rectified with a diode bridge rectifier four IGBT, used as 60Hz switched, reverse the polarity of the rectified current on every other half cycle of the utility voltage. Even though the high frequency link system used more power semiconductors, a net size, weight, and parts cost saving result compared to the other systems due to elimination of 60Hz transformer.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.11
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• pp.2017-2020
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• 2011

Flicker, which is also known as voltage fluctuation, is an electromagnetic phenomenon generated by large scale nonlinear loads, such as arc furnaces and welding machines. Since a severe and continuous flicker can cause to some damages to electrically sensitive loads as well as human's visual irritations, it needs to be appropriately managed by being accurately measured, quantified and assessed. In Korea, an equivalent 10-Hz flicker index, shortly ${\Delta}V10$, is used to determine the permission limit of flicker. This paper presents an efficient calculation of the flicker index by using a half-cycle sliding window and a recursive method, showing a concrete calculating procedure of ${\Delta}V10$ from the viewpoint of signal processing.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.46-49
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• 2001

An investigation into power conditioners that interface with photovoltaic array and utilities has been completed. The rating for this investigation is residential system(3-5kVA) that interface with a 220V single phase utility connection. As the result of this investigation, a 3kVA high frequency PWM IGBT inverter feeding a high frequency isolation transformer with a sinusoidal current wave was selected. The output of the transformer rectified with a diode bridge rectifier. four IGBT, used as 60Hz switched, reverse the polarity of the rectified current on every other half cycle of the utility voltage. Even though the high frequency link system used more power semiconductors, a net size, weight, and parts cost saving result compared to the other systems due to elimination of 60Hz transformer.