• 한국전자파학회논문지
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• 제26권11호
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• pp.999-1011
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• 2015

전자전(Electronic Warfare) 상황에서 레이다는 재머에 의해 전파교란공격(ECM: Electronic Counter Measures)을 받게 된다. Linear-FM 신호는 도플러 특성이 우수하고, 신호의 구현이 용이하여 레이다에서 주로 사용되어 왔지만, 반복된 패턴에 의해 피탐 확률이 높고, 신호 특성변수 추정이 가능하여 기만재밍에 취약하다. 최근 제안된 APCN(Advanced Pulse Compression Noise) 신호는 랜덤 진폭과 랜덤 위상코드로 이루어진 신호로서, 저피탐 성능이 우수한 신호이다. 하지만, APCN 신호를 비롯한 일반적인 위상코드 신호는 도플러 특성이 좋지 않으므로, 주파수 천이에 의해 신호수신 성능이 저하될 수 있다. 따라서 본 논문에서는 도플러 특성을 개선하기 위한 방안으로 랜덤 위상천이 및 부호율 천이(RPCR: Random Phase and Code Rate transition) 레이다 신호 파형을 제안하고, 도플러 성능과 저피탐 성능을 분석하였다. Ambiguity 함수를 이용하여 부호율 천이에 의한 도플러 특성 개선을 제시하며, WHT(Wigner-Hough Transform)을 이용한 신호 특성 변수 추정 실험을 통해 RPCR 신호의 저피탐 성능을 분석하고, 전파교란대응책(ECCM: Electronic Counter Counter Measures)으로의 가능성을 확인한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.240-242
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• 2005

It is well known that the PD (Partial Discharge) signals are generated if insulators have some defects such as voids in electrical facility and various PD detection methods are developed for preventing electrical troubles. So, an interest for the PD signals is higher and higher according to the high concern for the defects detection method of the aging electrical facility. When the equipment to detect PD signals installed at site and it works, a lot of noises flow in the equipment from surrounding situation and it will be mixed with original PD waveform. So we can not get the desired PD waveform. Therefore, there are many trial to reject or suppress the noise from the PD signals from long times ago. The greater of them used the hardware such as bridge circuits and frequency filters to suppress the noise. This paper proposed a novel noise rejection method in acquired data from PD detection equipment. The noise has the irregular phase and higher signal level than real PD, and noise decision is performed after inspection of pulse distribution in ${\Phi}$-q-n graph of acquired data from PD detection equipments. By experimental results on high voltage electric equipments, it is shown that proposed method has good performance. It is expected that this noise rejection technology is useful in numeric calculation and trend management of PD level.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1992년도 춘계학술대회
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• pp.184-185
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• 1992

This paper investigates the EEG waveform distortions caused by the transient responses of the various types of signal conditioning filters, which are generally introduced for the automated EEG analysis. This study explicitly simulates the filter responses to the typical EEG waveform models, and compares the distortions.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 A
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• pp.311-313
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• 1992

Automated analysis of EEG invariably requires the inclusion of a signal conditioning filter. This paper investigates the EEG waveform distortions caused by the transient responses of the various types of signal conditioning filters. This study explicitly simulates the filter responses to the typical EEG waveform models, and compares the distortions.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(5)
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• pp.207-209
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• 2000

In this paper, we developed a feature point detection algorithm that detects upstroke point(S), peak point(P), incisura(C) point from radial pulse waveform which obtained by using the developed radial pulse transducer. As the results of experiment the three kinds of parameters can extracted with effectively from normal radial pulse waveform.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1989년도 춘계학술대회
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• pp.19-22
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• 1989

This paper represents a syntactic peak detection algorithm which detects peaks in the ECG signal. In the algorithm, the input waveform is linearly approximated by "split-and-merge" method, and then each line segment is symbolized with primitive set. The peeks in the symbolized input waveform are recognized by the finite-state automata, which the deterministic finite-state language is parsed by. This proposed algorithm correctly detects peaks in a normal ECG signal as well as in the abnormal ECG signal such as tachycardia and the contaminated signal with noise.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1998년도 추계학술대회
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• pp.205-206
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• 1998

In this paper, we present the detection algorithm of interictal epileptic waveform using LVQ network and wavelet transform. First wavelet coefficients is used to represent the characteristics of a single channel EEG wave, and make a number of neural network input node smaller. Then, three-layer neural network employing LVQ network is trained and tested using parameters obtained from the first stage. This study showed that preprocessed EEG data can be successfully used to train ANNs to detect epileptogenic discharges with a high success.

• 대한전기학회논문지:전력기술부문A
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• 제48권1호
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• pp.16-21
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• 1999

The analysis of distribution line faults is essential to the proper protections of the power system. A high impedance fault test, which was carried in Korean electric power systems, it was found that a arcing phenomenon occurred during the high level portion of conductor voltage in each cycle. In this paper, we propose a new method for detection of high impedance faults, which uses the arcing fault current difference during high voltage and low voltage portion of conductor voltage waveform. To extract this difference, we diveded one cycle fault current into equal spanned four data windows according to the magnitude of voltage waveform and applied fast fourier transform(FFT) to each data window. The frequency spectrum of current wavefrom in each portion are used as the inputs of neural network and is trained to detect high impedance faults. The proposed method shows improved accuracy when applied to staged fault data and fault-like load.

• 한국전기전자재료학회논문지
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• 제32권2호
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• pp.151-156
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• 2019

The aim of this investigation is to detect specific waveforms in a distribution line prior to the occurrence of a fault. Conditions were introduced such that a feeder remote terminal unit (FRTU) of the distribution automation system selects and stores fault waveforms from the different waveforms detected in the distribution line. In addition, an algorithm was developed to detect specific waveforms from the fault waveforms stored using the FRTU. This algorithm exploits the duration and periodicity of harmonic changes in voltage and current. The efficacy of the algorithm was confirmed based on the measurements of fault waveforms in an actual distribution line. The results indicated that faults in a distribution line can be predicted via experimental measurements.

• 우주기술과 응용
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• 제3권2호
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• pp.144-153
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• 2023

기존의 군 위성 통신체계는 적의 재밍 공격 및 신호 수신을 대비한 특수한 통신 탑재체가 장착된 정지궤도 통신위성을 기반으로 하였는데, 무인체계 등 새로운 무기체계가 등장함에 따라 신규 통신 수요를 충족시킬 저궤도 위성 기반의 위성 통신체계의 필요성이 점점 커지고 있다. 본 논문은 큐브 위성 기반의 통신체계에 적합한 다양한 웨이브폼 기술과 미래 군 초소형 위성 통신체계의 운용 개념에 대해 소개한다.