• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.8
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• pp.678-688
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• 1990

In this paper, pSDF-based referance image is realized. Using BJTC(binary joint transform correlator) as the spatial plane correlator, optical pattern recognition for intraclass indentification is performed. Computer simulation shows that the correlation performance of BJTC is superior to that of JTC. Experimental results using BJTC reveal that correlation peak intensity is constant within the error range from 4.1% to 9.6% in intraclass indentification.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.269-270
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• 2015

상용 교류전원 환경에서 구동되는 조명용 OLED의 연구를 위하여 적색 형광 소자를 제작하여 교류 순방향 바이어스 인가에 따른 유기 전계발광 소자의 발광 특성을 분석하였다. 순방향 교류전원으로 구동된 유기발광 소자의 경우 직류 구동 방식과 비교하여 인가전압에 따른 전류 밀도와 발광 휘도는 유사한 특성을 나타내나, 높은 구동 전압에서 시간에 따른 열화가 빠르게 진행되는 결과를 나타내었다. 이러한 원인은 동일한 인가전압에서 교류의 경우 첨두치 전압이 높아 OLED 구동에 치명적인 열화의 원인으로 작용한다는 것을 실험적으로 확인하였다. 조명 용도로 교류전원 환경에서 OLED를 직결로 구동시키기 위해서는 소자를 안정적으로 구동할 수 있는 전압 범위의 첨두치 전압 조건에서 충분한 휘도와 효율 특성이 요구됨을 본 연구 결과를 통해 알 수 있다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.7
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• pp.1551-1557
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• 2013

A current velocity measurement radar estimates Doppler frequencies to extract the corresponding surface velocity information. Therefore, it is required to maintain the high degree of reliability and accuracy of Doppler frequency estimates. However, Doppler spectra of water surface return echoes can have very widely varying shapes according to measurement environments and weather conditions. Therefore, serious problems may arise in maintaining the reliability and accuracy of conventional velocity estimating algorithm in a radar sensor. Therefore, in this paper, a newly suggested algorithm is proposed for improvement using estimation of peak Doppler frequencies. The proposed method shows that the more accurate velocity measurement can be possible comparing with the conventional one.

• Water for future
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• v.29 no.2
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• pp.143-151
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• 1996

The dynamic responses in the subsurface outflow, surface saturation area, soil moisture storage are established by numerical experiments with Richards equation. In addition to this, the dynamical relationship between surface saturation area and subsurface outflow, and between surface saturation area and soil moisture storage are also determined by varying the hillslope shape, soil type, and boundary condition. The simulation results indicate that the dynamical relationships between surface saturation area and subsurface outflow, and between surface saturation area and soil moisture storage are approximated by the steadystate relationships. And the dynamic responses of subsurface outflow and surface saturation area are characterized by the double peaks although the rainfall pattern is asimple pulse input. As a result of numerical simulation, the physical mechanism for the occurrence of the double peaks is explained using the concept of variable source area.

• Journal of Biomedical Engineering Research
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• v.20 no.4
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• pp.451-459
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• 1999

During the electromyographic evaluation for the diagnosis of neuropathy, presence for site of lesion could be predicted by a detection of denervation potentials such as fibrillation potentials or positive sharp waves in a group of muscles. Unfortunately, since denervation potentials are distinguished by examiner's experience, it is possible to make mistake identifying endplate spikes as a denervation potential. The aim of the study was to extract parameters to make an algorithm for quantitative distinction between denervation potentials and endplate spikes. It will help to minimize the examiner's bias and to localize the site of lesion thus increase the reliability on EMG diagnosis. There types of signals, endplate spike, fibrillation potential and positive sharp wave were obtained from the EDB(extensor digitorum brevis) muscle using then neuropathic patients. Eight parameters such as duration, area, slope, peak-to-peak amplitude, positive peak negative peak amplitude, ratio of positive to negative peak amplitude, and number of phase were extracted and compared. As a results, peak-to-peak amplitude, positive peak amplitude, ratio of positive to negative peak amplitude showed statistically significant differences between endplate spikes and denervation potentials. It was concluded that those parameters could be used to establish an algorithm which will improve the accuracies in automated quantitative EMG diagnosis.

• Journal of the Korea Convergence Society
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• v.9 no.5
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• pp.1-6
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• 2018

In smart grid an accurate load forecasting is crucial in planning resources, which aids in improving its operation efficiency and reducing the dynamic uncertainties of energy systems. Research in this area has included the use of shallow neural networks and other machine learning techniques to solve this problem. Recent researches in the field of computer vision and speech recognition, have shown great promise for Deep Neural Networks (DNN). To improve the performance of daily electric peak load forecasting the paper presents a new deep neural network model which has the architecture of two multi-layer neural networks being serially connected. The proposed network model is progressively pre-learned layer by layer ahead of learning the whole network. For both one day and two day ahead peak load forecasting the proposed models are trained and tested using four years of hourly load data obtained from the Korea Power Exchange (KPX).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.9
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• pp.1818-1825
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• 2017

An Acoustic Doppler Current Profiler(ADCP) measures the current velocity and analyzes the degree of turbulence using Doppler effects of ultrasonic waves. Therefore, the autocorrelation or FFT spectrum estimates are obtained for extraction of current velocity in each spatial region. However, if the correlation method does not satisfy the assumption that the return signal spectra are symmetric Gaussian, the large bias errors can occur. Also, the accurate estimation of autocorrelation or FFT spectrum is difficult due to the short acquisition interval when the rapid changes of current velocity occur. Thus, in this paper, the estimation method of the autoregressive spectrum peak is suggested for the accurate current velocity measurement of both symmetric and asymmetric spectra. It is shown that estimation quality can be improved using the suggested method comparing with the conventional methods. Many return signals under the various environment are simulated and the results are compared and analyzed for evaluation of the suggested method.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.11
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• pp.111-118
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• 1990

In this paper, pSDF-based referance image is realized. Using BJTC (binary joint transform correlator) as the spatial plane correlator, optical pattern recognition for interclass identification and interclass discrimination is performed. Computer simulation shows that the correlation performance of BJTC is superior to that of JTC. Experimental results using BJTC reveal that correlation peak intensity is constant within the error rang from $4.1{\%}\to\9.6{\%}$ in interclass identification and correlation peak intensity of one class is two times higher than that of the other class in interclass discrimination, which indicates its superiority in discrimination sensitivity.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.7B
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• pp.983-988
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• 2001

컬러를 이용한 내용기반 영상검색의 대표적 방법에 해당하는 히스토그램 인터섹션은 영상에서 컬러가 가지는 값의 빈도 수를 이용하여 간단하면서도 효율적으로 영상을 검색하면서 영상 내에서의 물체의 이동, 회전에 대해 대처하는 장점을 가지는 방법이다. 그러나 영상에서의 위치 정보가 누락되어 다른 영상을 동일 영상으로 인지하기 쉽고, 동일 영상에 대해 조명 변화가 있을 때 히스토그램이 영향을 많이 받아 검색이 어렵다는 단점을 지닌 방법이다. 본 논문에서는 조명 변화가 있을 경우에도 검색이 가능한 방법을 제안한 것으로, 영상에 1차원 투영 기법을 적용해 투영 값이 큰 벡터들 간의 상대 거리를 이용하여 검색에 이용하였다. 검색 성능의 확인을 위하여 5가지 조명에서 얻은 영상 데이터베이스를 이용하여 실험하였으며, 실험 결과 기존의 방법에 비해 적은 색인 데이터 량으로 검색이 가능하면서 조명 변화에도 대응할 수 있는 검색 결과를 얻을 수 있었다.

• Electronics and Telecommunications Trends
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• v.24 no.6
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• pp.133-143
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• 2009

본 논문에서는 WRC-12 의제 8.1.1과 관련하여 ISM 기기로부터 전파통신 서비스의 영향을 파악할 목적으로 CISPR 통계적인 전파혼신 모형과 CISPR 11의 방사 기준치를 수신전력 관점에서 분석하였고, 산업공단에 설치된 열처리용 ISM 기기와 병원의 MRI로부터 복사되는 전파세기의 필드 측정치를 제시하였다. 본 논문의 분석결과에 따르면, 2.3GHz 주파수 대역에 적용되는 CISPR 11의 방사 첨두치 $110dB{\mu}V/m@3m$와 가중치 $60dB{\mu}V/m@3m$는 와이브로 보호를 위하여 재검토할 필요가 있다.