• 한국음향학회지
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• 제32권6호
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• pp.494-501
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• 2013

천해 수중 음향 채널의 배경잡음과 다중경로에 의한 비트 오류율(BER)을 경감하기 위해 Quadrature Phase Shift Keying(QPSK)에 전방 오류 정정 코드(FEC)로 부호화 비율 1/2의 길쌈 코딩(CC)을 적용하였다. 전송신호의 대역폭에 대한 채널의 일관성 대역폭의 비를 주파수 선택 지표로 정의하였고 주파수 선택지표에 따른 전송 신호의 BER과 비트 에너지 대 잡음비의 이득을 평가하였다. 실내 수조 실험 결과, 주파수 선택지표가 약 1.0 이하인 경우 BER은 이론적인 결과와 일치하고 비트 에너지 대 잡음비의 이득은 약 5 dB로 이론적인 결과와 일치한다. 주파수 선택 지표가 1.0 이상인 주파수 선택적인 다중경로 채널에서도 BER은 효율적으로 감소하지만 비트 에너지 대 잡음비가 일정크기 이상인 조건에서만 CC의 비트 오류 감소에 효과가 있다. 이러한 결과는 본 연구에서 정의한 주파수 선택 지표가 다중 경로 채널에서 CC의 성능 평가의 지표로 적용될 수 있다. 아울러 등화기를 적용하지 않고 저속 수중 음향 통신시스템에 효과적으로 BER을 줄일 수 있다.

• 약학회지
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• 제43권1호
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• pp.77-84
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• 1999

To search for less toxic antiherpetic agents, the inhibitory effects of natural naringenin on the plaque formation of herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) in Vero cells were examined by the plaque reduction assay in vitro. Naringenin inhibited plaque formations of HSV-l and HSV-2 in a dose dependent manner. It also exhibited more potent antiherpetic activity on HSV-l with selectivity index (SI) of 19.1 than on HSV-2 with SI of 5.7 The combined antiherpetic effects of naringenin with nucleoside antiherpetic agents, acyclovir and vidarabine, were examined on the multiplication of these two strains of herpesviruses in Vero cells by the combination assay. The results of combination assay were evaluated by the combination index (CI) that was calculated by the multiple drug effect analysis. The combinations of naringenin with acyclovir on HSV-l and HSV-2 showed more potent synergism with CI values of 0.28∼0.81 for 50%, 70%, 90% effective levels than those with vidarabine with CI values of 0.86-3.28.

• 수산해양기술연구
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• 제59권3호
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• pp.189-195
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• 2023

This study quantitatively evaluated size selectivity for three netting shapes (T0; regular, T45, T90) and hanging ratio (35%, 70%) of T0 netting used for trawl codend. The size selectivity experiment was performed in a tank using a cube experimental model with a length of 50 cm on one side and 389 experimental individuals, jack mackerel (Trachurus japonicus). In the selectivity analysis, a selectivity curve was created based on the selection ratio using a logistic function, and the 25%, 50%, and 70% selection length and selection range (SR) were obtained. The T0 netting was 19.54 cm when the 50% selective length, which is a selectivity evaluation index, had a hanging ratio of 35%, a selection range of 0.51 cm, and 22.70 cm and 3.08 cm for the hanging ratio of 70%. The T45 netting was 24.34 cm and 2.13 cm, and the T90 netting was 23.51 cm and 2.84 cm. The results of the T45 netting and the T90 netting are similar, and the 50% selection length and selection range were relatively larger than the T0 netting. There was a significant difference in the correlation between the circumference of the inner circle of the mesh by the shape of the netting and the body girth of the experimental individual (Pearson test, r = 0.86, p < 0.05). There was no significant difference in the correlation between the selection ratio by the T0 netting, T45 netting, and T90 netting with a 70% hanging ratio (one-way ANOVA, p > 0.05). The results of this study showed that selectivity such as T45 netting and T90 netting appeared when the hanging ratio, which maximizes the area of T0 netting, was maintained at 70%.

• 약학회지
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• 제38권3호
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• pp.345-350
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• 1994

Fourteen melandrin derivatives(I-XIV) were investigated on analgesic, anti-inflammatory and antiviral activities . Compound I [N-(p-hydroxybenzoyl)-5-hydroxyanthranilic acid methvl ester], Xll [N-(2-phenoxypropionyl)-5-hydroxy anthranilic acid propyl ester and XIV [N-(2-phenoxypropionyl)-5-hydroxyanthranilic acid exhibited analgesic activity in tail pressure and Randall-Selitto method. But no anti-inflammatory activity was shown. Compound I exhibited weak antiviral activity on Herpes simplex virus type I F strain by virus-induced cytopathic effect(CPE) assay and it's selectivity index(Sl) was 8.17.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1993년도 제2회 신약개발 연구발표회 초록집
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• pp.112-112
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• 1993

바이러스 치료제 개발을 위하여 합성된 핵산유도체 11개에 대한 in vitro 항바이러스 약효검색을 수행하였다. 검색대상 바이러스로서 외피보유 DNA 바이러스인 human herpesvirus에 속하는 herpes simplex virus type 1과 type 2에 대해서는 Vero 세포체계에서 3일 후 CPE 저해정도를 MTT 검색법으로 cytomegalovirus에 대해서는 HEL 세포체계에서 7일 후 Giemsa 염색법으로 약효를 측정하였다. 외피비보유 RNA 바이러스인 picornavirus에 속하는 poliovirus type 1과 type 3과 coxsackie B virus type 3에 대한 약효를 HeLa 세포체계에서 2일 후 CPE 저해정도를 MTT 검색법으로 측정하였다. 아울러 selectivity index를 구하기 위하여 Vero와 HeLa 세포에 대한 약물자체의 독성인 cytocidal effect를 MIT 검색법으로 측정하였다. 그 결과 항 herpesvirus 약효는 어떤 물질에서도 발견되지 않았으나 한 물질이 poliovirus type 1과 3에 대하여 selectivity index 10정도 (CC$_{60}$ 38 ug/ml, EC$_{50}$ 1-4 ug/ml)를 나타내었고 자세한 기작은 좀 더 조사할 필요가 있다.

• 문화기술의 융합
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• 제7권3호
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• pp.463-468
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• 2021

본 연구에서는 1.55um의 파장을 갖는 DFB 레이저에서 굴절률 격자와 이득 격자가 동시에 존재할 때, 오른쪽 거울 면에 반사가 일어나지 않도록 유전막 코팅을 하여 𝜌_r=0 이 되도록 하였다. 𝛿L>0인 경우일 때, 발진 모드에 대하여, 발진 주파수와 발진 이득의 특성을 해석했다. 좌측 거울면의 격자 위상이 𝜋에서부터 𝜋/2 계속 감소할 때, 각 모드의 그래프 선들이 좌측으로 조금씩 이동한다. 발진 모드의 문턱 이득이 가장 낮은 경우는 𝜅L=10인 경우이고, 이때 모드 선별성은 상대적으로 낮다. 모드 선별성이 우수한 경우는 𝜅L=0.5에서부터 𝜅L=6 정도까지이고, 이 경우 주파수 안정성이 우수하다. 두 개의 벽개면을 갖는 경우와 비교하면, 한 개의 무반사면을 갖는 경우, 발진 모드의 문턱 이득이 증가하지만 모드 선별성은 2배 정도 더 우수해 진다.

• 한국광학회지
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• 제13권2호
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• pp.134-139
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• 2002

금속-클래드 평면 도파로와 접합된 측면 연마된 광섬유의 파장 및 편광 선택성에 관한 실험 결과를 보고한다. 금속의 두께와 최상부층의 굴절률을 포함한 평면 도파로의 구조가 소자의 광전송 특성에 미치는 영향을 측정하였고 그 결과를 설명하였다. 높은 파장 선택성과 편광 선택성을 가지는 조건을 예측하였고 실험으로 검증하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.381.1-381.1
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• 2014

In this study, we investigated the deposition behavior and the etch resistivity of plasma polymerized carbon hardmask (ppCHM) film with the variation of process temperature. The etch resistivity of deposited ppCHM film was analyzed by thickness measurement before and after direct contact reactive ion etching process. The physical and chemical properties of films were characterized on the Fourier transform infrared (FT-IR) spectroscope, Raman spectroscope, stress gauge, and ellipsometry. The deposition behavior of ppCHM process with the variation of temperature was correlated refractive index (n), extinction coefficient (k), intrinsic stress (MPa), and deposition rate (A/s) with the hydrocarbon concentration, graphite (G) and disordered (D) peak by analyzing the Raman and FT-IR spectrum. From this experiment we knew an optimal deposition condition for structure of carbon hardmask with the higher etch selectivity to oxide. It was shown the density of ppCHM film had 1.6~1.9 g/cm3 and its refractive index was 1.8~1.9 at process temperature, $300{\sim}600^{\circ}C$. The etch selectivity of ppCHM film was shown about 1:4~1:8 to undoped siliconoxide (USG) film (etch rate, 1300 A/min).

• Fisheries and Aquatic Sciences
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• 제11권1호
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• pp.61-69
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• 2008

Using empirical data of fish performance and physiological limits as well as physical stimuli and environmental data, a cod-end selectivity model based on a chaotic behavior model using the psycho-hydraulic wheel and neural-network approach was established to predict fish escape or herding responses in trawl and cod-end designs. Fish responses in the cod-end were categorized as escape or herding reactions based on their relative positions and reactions to the net wall. Fish movements were regulated by three factors: escape time, a visual looming effect, and an index of body girth-mesh size. The model was applied to haddock in a North Sea bottom trawl including frequencies of movement components, swimming speed, angular velocity, distance to net wall, and the caught-fish ratio; simulation results were similar to field observations. The ratio of retained fish in the cod-end was limited to 37-95% by optomotor coefficient values of 0.3-1.0 and to 13-67% by looming coefficient values of 0.1-1.0. The selectivity curves generated by this model were sensitive to changes in mesh size, towing speed, mesh type, and mesh shape.

• BMB Reports
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• 제40권6호
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• pp.1090-1094
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• 2007

Melittin (ME), a linear 26-residue non-cell-selective antimicrobial peptide, displays strong lytic activity against bacterial and human red blood cells. To design ME analogue with improved cell selectivity, we synthesized a melittin diastereomer (ME-D) with D-amino acid in the leucine zipper sequence (Leu-6, Lue-13 and Ile-20). Compared to ME, ME-D exhibited the same or 2-fold higher antibacterial activity but 8-fold less hemolytic activity. Circular dichroism analysis revealed that ME-D has much less $\alpha$-helical content in $\alpha$-helical content in the presence of zwitterionic EYPC/cholesterol (10 : 1, w/w) liposomes compared to negatively charged EYPE/EYPG (7 : 3, w/w) liposomes. The blue shift of the fluorescence emission maximum of ME-D in zwitterionic EYPC/cholesterol (10 : 1, w/w) liposomes was much smaller than in negatively charged EYPE/EYPG (7 : 3, w/w) liposomes. These results suggested that the improvement in therapeutic index/cell selectivity of ME-D is correlated with its less permeability to zwitterionic membranes.