• Proceedings of the Materials Research Society of Korea Conference
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• 2006.05a
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• pp.25.1-25.1
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• 2006

• Journal of The Korean Radiological Technologist Association
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• v.29 no.1
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• pp.44-49
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• 2003

Purpose : $^{99m}Tc-DMSA$ renal scan can be used in the evaluation of relative renal function and some anatomy. The relative renal function can be assess by measurement of $^{99m}Tc-DMSA$ uptake by the individual kidney. Renal counts

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.12B
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• pp.1087-1098
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• 2006

This study is unlike common Input-Output Analysis in the point that both RAS and methods are applied to the dynamic Input-Output Model simultaneously. We have analyzed the propagation effects on the regional economy from the investment generated by u-City construction in Wha-sung and Dong-tan City. The main results of the study are as follows. The total induced effect on production according to u-City construction in Wha-sung and Dong-tan City is estimated about 2.9 times. On the other hand, u-City industry is appreciated as a industry which a forward linkage effect is very high while a backward linkage effect is not that high.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.336-336
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• 2012

수명 측정법과 동시 계수 도플러 넓어짐 양전자 소멸 분광법으로 p형과 n형 실리콘 시료에 0, 3.98 MeV 에너지를 가진 $0.0{\sim}20.0{\times}10^{13}$ protons/$cm^2$ 양성자 빔 조사에 의한 결함을 측정하여 실리콘 결함 특성에 대하여 조사하였다. 양전자와 전자의 쌍소멸로 발생하는 감마선 스펙트럼의 전자 밀도 에너지를 수리적 해석 방법인 S-변수와 열린 부피 결함에 대한 측정법으로서 양전자 수명 ${\tau}1$과 ${\tau}2$, 이에 따른 밀도 I1과 I2를 사용하여, 시료의 구조 변화를 측정하였다. 본 연구에서 측정된 S-변수와 양전자 수명은 시료에 조사된 양성자의 빔 에너지에 따라 변화하기보다 양성자 조사량의 변화에 따라 결함이 증가하였으며, 양전자 수명 측정과 같은 경향을 보여준다. SRIM의 결과로써, 양성자 조사 에너지에 따른 Bragg 피크 때문에 양성자는 시료의 특정 깊이에 주로 결함을 형성하여 시료 전체에는 결함으로 잘 나타나지 않기 때문이다. 빔의 조사량에 따른 결함의 영향이 더 큰 것으로 나타났다.

• Journal of Broadcast Engineering
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• v.5 no.1
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• pp.123-129
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• 2000

This paper addresses a new double detection algorithm which is based on the fuzzy control in the adaptive echo canceller of communication system. In this method, the two input of the fuzzy inference for detecting double talk condition are used. The one is the cross-correlation coefficient between the error signal and the primary signal which is the summed signal of the real echo signal and the near-end signal. The other is the cross-correlation coefficient between the estimation error signal and the primary signal. The fuzzy controller made a fuzzification for two inputs by the membership functions of trapezoid and them became the composition using inference rules. The composed result is defuzzificated by the center gravity method. The output is compared with two threshold values to detect double talk and echo path variation effectively. It is confirmed by computer simulation that this fuzzy double talk detector is able to track echo path variation accurately.

• Journal of the Korean Vacuum Society
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• v.18 no.6
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• pp.447-452
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• 2009

Enhance signal-to-noise ratio, Coincidence Doppler Broadening positron method has been applied to study of characteristics of BaSrFBr:Eu film sample. In this investigation the numerical analysis of the Doppler spectra was employed to the determination of the shape parameter, S, defined as the ratio between the amount of counts in a central portion of the spectrum and the total counts of whole spectrum. The films were exposed by 0, 3, 5, and 7.5 MeV proton beams ranging from 0 to $10^{13}$ ptls. The S-parameter values were increased as increasing the exposed time and the energies, that indicated the defects generate more.

• Korean Journal of Optics and Photonics
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• v.8 no.6
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• pp.456-460
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• 1997

Several methods of aligning ring type cavities have been investigated for long time. The measurement of cavity transmission spectrum control is somewhat effective due to aligning cavity with measuring cavity loss at the same time. In this research, four mirrors are aligned and attached by the measurement of pulse width of the transmitted light. The intracavity loss is optimized to about 0.98%, giving the calculated total reflection coefficient of about 99.02%.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.7 no.4
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• pp.667-680
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• 1995

튜브 내의 입구영역에서 난류 유동에 의한 대류와 비회복사(non-gray radiation)가 동시에 일어날 때의 열전달특성을 수치해석적으로 연구하였다. 작동유체는 이산화탄소, 수증기, 질소의 혼합가스라고 가정하였다. 지배방정식을 계산하기 위해 유한차분법이 이용되었고, 복사전달방정식을 이차편미분방정식으로 바꾸기 위해 P-1 근사법이 사용되었다. 그리고 혼합가스의 비회흡수계수(non-gray absorption coefficient)는 지수광폭밴드모형(exponential wide band model)을 이용해서 구하였다. 열전달특성에 대한 온도조건의 영향을 조사하기 위해 튜브의 축방향에 대한 평균 온도와 뉴셀트수(Nusselt number)의 변화를 몇 가지 다른 온도조건에 대해 나타내었다. 또한, 가스의 성분조성에 대한 영향을 조사하였으며, 이러한 결과에 기초해서 튜브 내에서 난류유동에 의한 대류와 비화복사가 동시에 일어날 때의 복사 뉴셀트수를 쉽게 예측할 수 있는 방법을 제시하였다.

• The Journal of the Acoustical Society of Korea
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• v.19 no.7
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• pp.34-41
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• 2000

This paper proposes a new double-talk detection algorithm which is based on the fuzzy rules, in the adaptive echo canceller of telecommunication system. In this method, the two inputs of the fuzzy inference for detecting double-talk condition are used. One is the cross-correlation coefficient between the error signal and the primary signal which is the summation of the real echo signal and the near-end signal. The other one is the cross-correlation coefficient between the estimation error signal and the primary signal. The fuzzy controller makes a fuzzification for two inputs by the membership functions of trapezoid does the max-min composition using if-then rules. The composed result is defuzzificated by the center gravity method. And by defuzzificated values, the double-talt the echo path variance, and the echo path variance during the double-talk are detected. It is confirmed by computer simulation that this fuzzy double-talk detector is able to estimate the double talk and the echo path variation condition, and even track echo path variation more accurately than the conventional algorithm during the double-talk period.

• Journal of the Korean Society for Precision Engineering
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• v.11 no.2
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• pp.75-84
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• 1994

기계가공프로세스에서 절삭공구의 마멸과 채터진동은 공작기계의 가동율과 생산성을 크게 저해하는 요인이 되고 있다. 본 연구에서는 공구마멸과 채터현상이 혼재하는 상황에서, 이들 두 현상을 동시에 검출하는데, AE 및 가속도센서에서 검출된 신호와 AR계수 및 주파수대역 평균에너지를 특징입력으로 하는 인공신경회로망을 이용하였다. 그 결과, 공구마멸과 채터현상에 대응하는 서로 다른 신호특징의 차이를 동시에 식별하는 데 인공신경 회로망의 유용성을 입증하였으며, 시계열모델의 AR계수(70 .approx. 90%)보다는 주파수대역에너지법의 평균에너지 (80 .approx. 100%)를 신경회로망의 특징입력으로 하는 경우가 높은 성공률을 나타내었다.