• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1997년도 춘계학술대회논문집; 경주코오롱호텔; 22-23 May 1997
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• pp.69-74
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• 1997

In this paper we derive relations which describe the geometry and kinematics of contact between the travelling wheel and stepped comb joint. From which we can obtain the impulse, impulsive force and its time interval due to travelling wheel impact which can not be taken from Carter's model or Newland and Cassidy's. The calculated transient responses of the comb joint structure to travelling wheel impact reveals that the proposed wheel contact model and Carter's give very similar results but Newland Cassidy's model make a quite different results from the others.

• 약학회지
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• 제47권3호
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• pp.176-179
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• 2003

A library of unlimited number of novel lectins with diverse specificities has been previously generated by randomly mutating the carbohydrate-recognition domain of Maackia amurensis hemagglutinin (MAH). To establish the experimental environment capable of selecting high affinity mutant lectins in E. coli, phage display system was adapted. Carbohydrate binding capacity of two phagemid vectors, pComb3 and pComb8 displaying wild-type MAH lectin was assessed. Specific bindings of pComb3 and pComb8 phages expressing w.t. MAH to affinity-purified polyclonal anti-MAH antibody and to glycophorin was demonstrated. Both phages also showed strong hemagglutinating activity to intact but not sialidase-treated human erythrocytes, which is consistent to the specificity of native MAH. Taken together, two different phage display vectors successfully allowed the expression of active MAH as a fusion protein on the surface of bacteriophage, which will lead to preparation of unique plant lectins with high affinity toward a variety of carbohydrate chains.

• JSTS:Journal of Semiconductor Technology and Science
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• 제7권3호
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• pp.177-182
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• 2007

This paper presents the see-saw type RF MEMS switch based on a single crystalline silicon structure with narrow gap vertical comb. Low actuation voltage and high isolation are key features to be solved in electrostatic RF MEMS switch design. Since these parameters in conventional parallel plate RF MEMS switch designs are in trade-off relationship, both requirements cannot be met simultaneously. In the vertical comb design, however, the actuation voltage is independent of the vertical separation distance between the contact electrodes. Therefore, the large separation gap between contact electrodes is implemented to achieve high isolation. We have designed and fabricated RF MEMS switch which has 46dB isolation at 5GHz, 0.9dB insertion loss at 5GHz and 40V actuation voltage.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2002년도 춘계종합학술대회
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• pp.514-517
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• 2002

광 공진기내에 음향광학소자(AOM)를 사용하여 FSF(Frequency-shifted feedback) 레이저를 개발하였다. 공진기는 1차 회절광에 의한 feedback loop로 구성된다. FSF 레이저 출력은 수백 PHz/s의 초고속 주파수 chirp을 갖는“chirped frequency comb”이라 불리는 주파수 출력을 보여준다. FSF 레이저를 광원으로 광거리 계측에서는 chirped 주파수 comb을 이용하여 거리를 알 수 있다.

• Journal of the Optical Society of Korea
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• 제11권3호
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• pp.124-129
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• 2007

For the first time we compare two kinds of optical frequency combs, one of which is based on a Ti:sapphire femtosecond laser and the other is based on a mode-locked erbium-doped fiber laser. The comparison is performed by measuring an optical frequency standard with these two combs simultaneously. The two frequency measurements agree within 1.8 Hz ($3.8{\times}10^{-15}$) with the uncertainty of 17.2 Hz ($3.6{\times}10^{-14}$), from which it can be concluded that the Ti:sapphire-based frequency comb and the fiber-based frequency comb have no systematic discrepancy at this level of uncertainty.

• 대한음성학회:학술대회논문집
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• 대한음성학회 2003년도 5월 학술대회지
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• pp.203-206
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• 2003

In this paper, we employ the adaptive comb filtering for effective noise reduction in mobile communication environment. Adaptive comb filtering is a well- known method for noise reduction, but requires the correct pitch period and must be applied just in voiced speech frames. To satisfy these requirements we use two kinds of information extracted from speech packets, one of which is the pitch period information measured precisely by a speech coder and the other is the frame rate information related to a decision on speech or silence frame. Experiments on speech recognition system confirm the efficiency of this method. Feature parameters employing this method give superior performance in noise environment to those extracted directly from output speech.

• 한국정밀공학회지
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• 제22권5호
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• pp.72-79
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• 2005

Gearing system emits inconsistent noise from gear teeth impact in case of gear defects. But, it is not easy for inspection operator in production line to distinguish objectively the defective product. Therefore, customer complains continuously bad noise of the geared motor. Because impulsive signal at low frequency has a tendency not to appear in frequency domain, it is difficult to separate the gear inconsistent noise of defective gear from overall geared motor's noise using general signal processing method such as FFT. In this paper, the method to estimate more objectively the inconsistent noise of gearing system and to measure the quantities is suggested. Suggested method uses Cepstrum, Autocorrelation, Comb Lifter and Inverse Cepstrum by turns to make objective quantities about noise level.

• 전자통신동향분석
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• 제34권5호
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• pp.91-98
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• 2019

Optical frequency comb generators have been investigated as a signal source capable of generating highly stabilized ultrafast pulse lasers. The precise control of the optical frequency comb spacing by RF clock signals has led to a revolutionary paradigm shift in the precise measurement of time and frequency. Optical frequency combs also have advantages such as stable frequency spacing, stable number of lines, and robustness. Owing to these characteristics, optical frequency combs have been applied to the fields of high precision optical clock, communication, spectroscopy, waveform generation, and astronomy. In this article, we introduce the properties (i.e., generation methods, advantages, and so on) of various optical frequency combs, and discuss the expected future technological trends and applications.

• 한국통신학회논문지
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• 제21권12호
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• pp.3265-3276
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• 1996

문자인식에 대한 연구는 주로 한글인식에 대해서만 이루어져 왔는데, 대부분의 문서는 한글 뿐만 아니라 여러 종류의 문자가 포함되어 있다. 따라서, 본 논문에서는 다중 크기, 다중 활자체, 다자종 문자가 포함되어 있는 한글문서를 인식할 수 있는 문자인식 시스템을 구현하였다. CombNET 구조를 갖는 신경회로망을 자종별로 구성하여, 문자인식시에 문자를 구별하지 않고 인식하는 방법을 제안하였다. CombNET 구조의 상단부를 차지하는 Kohonen의 SOFM 신경망을 이용하여 한글과 한자는 36개, 영숫자는 16개의 유형으로 분류하고 각 유형에 대해서 CombNET 구조의 하단부에 있는 BP 네트워크를 이용하여 문자인식을 수행하였다. 실험결과 학습 데이타에 대해서는 95.6%의 인식율을 나타내었고, 실제문서에 대해서도 92.6%의 인식율과 초당 10.3자의 인식속도를 보임으로써 제안된 인식 시스템의 유효성을 입증하였다.

• 한국응용곤충학회지
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• 제35권3호
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• pp.216-220
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• 1996

Drosophila simulans와 D. mauritiana는 동일 subgroup에 속하는 동포종으로, 전자는 전세계 분포종이며, 후자는 Mauritius 섬에만 서식하는 지역종이다. D. simulans의 성즐(sex comb)은 약 9.83개의 치열로 구성되어 있으며, D, mauritiana의 성즐 치열수는 약 12.90개 정도이다. D. simulans의 생식궁(genital arch)은 큰 반월형이며, D. mauritiana는 가는 막대형이다. 두 종간 성즐의 치열수와 생식궁의 형태적 차이에 미치는 X 염색체의 효과를 알아보기 위한 유전적 분석을 실시하였으며, 이를 위하여 X 염색체상 돌연변이 유전자들을 가지는 D. simulans 계통과 정상의 D. mauritiana 사이의 잡종 {TEX}$F_{1}${/TEX}을 부모계통과 역교배를 실시하여 얻은 자손들을 대상으로 상기 두가지 형질의 분석을 실시하였다. F1의 성즐 치열수는 평균 11.79개 정도였으며, 외부생식기의 일반적인 형태는 D. simulans와 D. mauritiana의 중간형이었다. 성즐의 치열수와 외부생식기의 주요 특징분석에서 X 염색체 효과에 따른 유의적인 차이는 거의 없는 것으로 나타났다.