• 전자공학회논문지 IE
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• 제43권2호
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• pp.75-79
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• 2006

블라인드 기법은 훈련열 없이 검출하고자 하는 사용자의 최소한의 정보만을 가지고 정보 검출이 가능한 방법이다. 본 논문에서는 직접 대역 확산 코드 분할 다중 접속 시스템에서 다중사용자 간섭을 제거하기 위해서, 혼합된 비용함수를 사용하는 블라인드 다중사용자 검출기를 제안하였다. 제안된 블라인드 다중사용자 검출기의 비용함수는 LMS와 LMF를 혼합한 형태로 이루어져있으며, 제안된 다중사용자 검출기의 성능을 평가하기 위해서 가우시안 채널 하에서 BER을 비교 하였다. 모의실험 결과, 사용자가 20 명 존재하는 경우, 제안된 블라인드 검출기가 블라인드 MOE 다중사용자 검출기에 비해 약 3dB정도 더 나은 성능을 지님을 확인 할 수 있었다.

• International Journal of Industrial Entomology and Biomaterials
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• 제9권1호
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• pp.29-33
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• 2004

Low molecular weight silk fibroin (LMSF), which was prepared by hydrolysis of silk fibroin using high-temperature and high-pressure method, was found to inhibit the oxidation of L-3,4,-dihydroxyphenylalanine (L-DOPA) catalyzed by mushroom tyrosinase (EC 1.14.18.1). LMSF contained mostly free amino acids such as L-glycine, L-alanine, and L-serine and oligopeptides, mainly glycine-alanine dimer. As a result of analyzing the inhibition kinetics from Lineweaver-Burk plots, L-glycine and glycine-alanine dimer showed noncompetitive behavior while uncompetitive behavior was observed in L-alanine, and L-serine. When weight percent concentration of ${ID_50}$ was compared, L-glycine was most effective on the inhibition and LMSF was also good enough for the inhibition effect of tyrosinase activity. LMSF showed a mixed-type inhibition and the inhibitory mechanism of LMSF might be caused by free amino acids and oligopeptides. As a result of spectroscopic observation with time, initial rate of increase of DOPAchrome decreased remarkably and the time to reach maximum absorbance increased as an increase of the concentration of L-glycine, meaning that L-glycine made itself mainly responsible for the formation of chelate with ${Cu^2+}$ in tyrosinase. However, in case of L-alanine, L-serine, and especially glycine-alanine dimmer, the production of DOPAchrome after an arrival at maximum absorbance decreased, indicating the production of adducts through the reaction with DOPAquinone.