• 대한전기학회논문지:시스템및제어부문D
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• 제52권9호
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• pp.547-553
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• 2003

In this paper, we designed the PC-based analyzer of the power spectral density that could estimate the heart rate variability from time series data of R-R interval. The power spectral density estimated that it applied the autoregressive model to the measured electrocardiogram during a short period. Also, the characteristics of the designed analyzer are that it could process of the signal filtering, the generation and recomposition of time series and the feature extraction at the same time. Especially the analyzer reconstructed which applied the lowpass filter of the time series composed by the linear interpolation so as to enhance the signal-to-noise feature. We could estimate the power spectral density that confirmed a variety of power peak with low frequency range and high frequency rang of autonomic nerve by the heart rate variability.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.462-463
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• 2006

본 논문에서는 당사에서 개발한 Digital Relay 및 Meter와 같은 IED들의 고장/이벤트 파형을 분석하는 툴인 Wave Analyzer를 소개한다. 기존 당사 파형 분석 툴들은 각기 하나의 IED에 대해서만 적용 가능하였으나 Wave Analyzer는 당사의 모든 IED에 대해 적용 가능하도록 통합형으로 개발하였다. 또한 고조파 분석, 벡터 다이어그램 등 파형 분석에 필요한 다양한 기능을 제공한다. Wave Analyzer는 다양한 기능을 가지고 있으며 모든 IED에 적용할 수 있어 당사 IED를 사용하는 사용자들에게 보다 편리함과 유용함을 제공할 것이다.

• 전력전자학회논문지
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• 제6권4호
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• pp.362-368
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• 2001

본 연구는 전력품질을 평가할 수 있는 DSP기반 3상 전력품질 분석시스템의 국산화 개발을 목표로 하고 있다. 전력분석 알고리즘은 시간영역의 상관함수 이론을 사용하였고, 독립형 TMS320C31 DSP 보드에 의해 전력을 실시간으로 분석하여 LCD와 D/A변환기로 출력하였다. 2PH의 모터와 그 구동장치(인버터)의 전력품질을 분석함으로서 외국산 제품과 비교하여 그 성능과 정밀도 등을 검토하였다. 개발된 시스템은 종전의 대전력용 전력분석장비에 비해 사용하기 쉽고, 설치공간과 가격이 크게 감소되며 저전력의 전력품질 분석에 적합한 시스템입을 확인하였다.

• KEPCO Journal on Electric Power and Energy
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• 제1권1호
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• pp.79-84
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• 2015

Transformer is widely used element on power system and industrial area. Especially the transformers installed at power system are exposed to an environment of arbitrary changed. Thus the prediction of degradation and the analysis of response to impulse are important. To conduct those works, the electrical characteristics of system should be analyzed, effectively. But the analysis of electrical characteristic in electric machine level such as pole and pad-mounted transformer is almost no, thus commercial VNA (Vector Network Analyzer) is used to getting the response in wide frequency range. However, the output power of VNA is usually under 10mW, so verification for effectiveness of measuring electrically large component should be conducted, firstly. Next, after getting total S-parameter of transformer, predicting impulse response can be performed in time-domain with circuit simulator. In this paper, it is introduced that verification effectiveness of VNA using transfer function from SFRA (Sweep Frequency Response Analyzer), firstly. Next, total S-parameter, six by six matix form, was built using measured 2 port S-parameter from vector network analyzer. To get the response to impulse which is defined by IEC 60060-1, time-domain simulation is conducted to ADS (Advenced Design System) circuit simulator.

• Journal of the Optical Society of Korea
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• 제7권4호
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• pp.249-252
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• 2003

A simple multi-channel spectrum analyzer using an InGaAs array sensor and a diffraction grating is proposed and developed for high-capacity optical transport networks. With the developed multichannel spectrum analyzer, we could measure signal power, wavelength, and optical signal-to-noise ratio of each channel for multi-channel optical signals with 100 GHz and 50 GHz channel spacing, simultaneously. We could measure each channel power and wavelength with a deviation of less than 0.2 dB and 0.063 nm, respectively. We have obtained optical signal-to-noise ratio with a deviation of less than 1.0 dB compared with conventional optical spectrum analyzer in the wide input power range between -42 dBm and -27 dBm per channel.

• 한국통신학회:학술대회논문집
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• 한국통신학회 1991년도 추계종합학술발표회논문집
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• pp.103-106
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• 1991

Spectrum Analyzer is a useful measure instrument to display the distributed power of electrical signal as a function of frequency. It adopts the superheterodyne receiver, which mixes RF with L0 to output IF. So in this paper, two GHz-order microstrip low-pass filters, 2-section wilkinson power divider, and singly balanced diode mixer have been designed and implemented necessary to make the frequency converter applied to RF spectrum analyzer.

• 한국전기전자재료학회논문지
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• 제23권10호
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• pp.809-813
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• 2010

Frequency domain measurement of propagation loss for ultra high frequency (UHF) partial discharge in the winding of power transformer using a spectrum analyzer and pulse generator is presented. We compared the performance of the method using a network analyzer with and without a winding. Using a network analyzer simplifies the measurement and offers better dynamic range and frequency range. It also provides precise propagation loss within the winding in frequency domain at UHF range. We applied this method to measure UHF propagation loss of transformer mock-up, modeled 154 kV 20 MVA power in KEPCO substation.

• 한국정보통신학회논문지
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• 제17권10호
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• pp.2431-2438
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• 2013

본 논문에서는 휴대용 유중가스 분석기에 대해 연구 및 개발 하였다. 제안된 휴대용 유중가스 분석기는 전력기기로부터 절연유 내의 소량의 가스를 추출하여 비정상적인 열적 정보를 얻어 분석하는데 유용하게 쓰인다. 분석된 정보로부터 전력기기의 안정성을 평가할 수 있다. 본 논문에서는 기존의 고가의 시설기반의 고정형 유중 가스 분석기를 사용함으로써 발생되는 직간접적인 문제점을 해결하기 위해서 광음향 분광법 기반의 소형화된 휴대용 유중가스 분석기를 제안하고 실험적으로 검토하였다. 제안된 휴대용 유중 가스 분석기는 사용하기 편하고 실시간으로 전력기기의 열적 정보를 분석할 수 있다. 제안된 휴대용 유중가스 분석기가 현재의 전력기기 유중가스 분석에 사용된다면, 전력기기의 유중가스 분석주기를 줄임으로써 안정성을 향상 시키고 열적 이상 정보에 대하여 긴밀하게 대응할 수 있다.

• 정보학연구
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• 제8권3호
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• pp.25-33
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• 2005

This paper describe a method for measuring line impedance as a function of frequency for an energized powerline in normal operation. A small sinusoidal signal of a powerline communication utility frequency 30khz$\sim$1Mhz band is continuously injected into the line, and a implemented impedance analyzer calculates the indoor powerline channel impedance from the measured magnitude and phase of resulting voltage and current. The impedance measurement is executed over a range of frequencies to produce a wideband impedance versus frequency characteristic. Implemented impedance analyzer can analysis powerline communication environments measuring line impedance due to load caused in indoor. And measured analysis information through the database can use to evaluate performance of modem and to decide test environment standard.

• 대한의용생체공학회:의공학회지
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• 제38권4호
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• pp.183-189
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• 2017

Electrosurgical Unit(ESU) is medical equipment that cut or coag tissues using electrical energy. It is used in hospitals' outpatient clinic room and operating room. Improper use of an ESU may cause fatal injuries to the patient, such as burns. So, before using an ESU, make sure that it is supplying enough energy for cut and coag by measuring the output power and checking the output power cable. In this study, we developed a simple ESU power measurement system PW100 that allows anyone to check the basic output power. And PW100 can check the state of the cable associated with the output power before using ESU. Then, we compared the measured output power of the PW100 with an ESU Analyzer which was commercialized, and compared the performance. In the experiment, the output power measured by the PW100 was lower value than an ESU Analyzer's that. However, the PW100's output power measured in the 5% error range and showed stable reproducibility by a low %RSD value.