• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제16권1호
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• pp.85-89
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• 2010

대부분의 영상들은 여러 객체 영역들의 시각적인 특징과 각각의 의미들의 조합으로 구성되어 있다. 그러나 일반적으로 영상 처리를 위한 컴퓨터 시스템들은 영상을 특정 객체 영역의 의미 정보 단위로 해석하지 못하기 때문에 사람이 영상을 인지하는 것과 의미적인 차이(semantic gap)가 발생한다. 본 논문에서는 이러한 문제점을 극복하기 위하여 각 객체 영역 단위에서 추출한 고유한 특징점들을 고차원의 의미 정보로 모델링하여 영상을 분류하는 방법을 제안한다. 제안하는 방법은 객체 단위로 추출된 고유한 특징점들의 의미 정보를 특정 객체 영역을 인식하기 위한 의미 단서로 이용한다. 이를 통하여 기존의 영상 분류 방법들에 비하여 인간의 인지 능력과 유사하고 보다 효율적으로 영상을 분류할 수 있는 장점이 있다. 실험 결과는 다양한 카테고리 종류의 영상에 대하여 제안하는 방법의 효과적인 분류 성능을 보여준다.

• 한국지능시스템학회논문지
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• 제22권6호
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• pp.748-753
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• 2012

본 논문에서는 최적 pRBFNNs 패턴분류기 기반 3차원 스캐너를 이용한 얼굴인식 알고리즘을 설계한다. 일반적으로 2차원 영상을 이용한 얼굴인식 시스템은 사진의 명암도를 이용하여 얼굴의 특징을 추출하게 된다. 그렇기 때문에 빛이나 조명, 또는 얼굴 포즈와 같은 환경 변화들은 시스템의 성능을 저하시킨다. 따라서 본 논문에서 제안된 얼굴인식 알고리즘은 2차원 얼굴인식 시스템의 한계를 극복하기 위하여 3차원 스캐너를 사용하여 설계한다. 먼저 3차원 스캐너를 이용하여 얼굴 형상을 스캔하고 스캔된 얼굴 형상은 포즈 보상 과정을 통하여 정면으로 변환된다. 그 후에 Point Signature 기법을 사용하여 얼굴의 깊이 정보를 추출하고 마지막으로 고차원 패턴인식 문제에 대한 해결을 위하여 최적화된 pRBFNNs (Polynomial-based Radial Basis Function Neural Networks) 모델을 사용하여 인식성능을 확인한다.

• 약학회지
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• 제52권3호
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• pp.165-171
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• 2008

To develop effective skin whitening agents, we tested natural herbal extracts for their melanogenic inhibitory activities. Sedum samentosum was selected for its inhibitory effect on melanogenesis in B16 melanoma cells. Ethanolic extract of S. samentosum (SSE) was evaluated for antioxidative effect and tyrosinase inhibitory activity of melanogenesis. We investigated the changes in protein level and mRNA level of tyrosinase, tyrosinase related protein (TRP)-1 and TRP-2 by using western blotting and RT-PCR, respectively. SSE showed scavenging activities of free radicals and reactive oxygen species (ROS) with the $IC_{50}$ of 342.7 $\mug/ml$ against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and 64.69 $\mug/ml$ against superoxide radicals in the xanthine/xanthine oxidase system, respectively. SSE treatment suppressed the biosynthesis of melanin up to 46% and reduced tyrosinase activity up to 51% at 100 $\mug/ml$ in B16 melanoma cells. The tyrosinase activity and tyrosinase expression in B16 melanoma cells were reduced in a dose-dependent manner by SSE. Also, SSE was able to significantly inhibit tyrosinase and TRP-1 expression in mRNA level. These results suggest that SSE inhibited melanin production which may be dependent on tyrosinase activity and expression in B16 melanoma cells, and an effective whitening agent for the skin.

• 한국식품저장유통학회지
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• 제14권2호
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• pp.183-187
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• 2007

매실박 메탄을 추출물의 항균력을 조사한 결과, $500{\mu}g/mL$ 이상의 농도에서 뚜렷한 항균활성을 보였고, 광역의 변패성 미생물들에 대하여 항균활성을 나타내었다. 또한, 매실박 메탄올추출물의 항균물질은 높은 온도$(100^{\circ}C)$에서 30분 동안 안정하였으며, 넓은 범위의 pH(3-11)에서 안정성을 나타냈다. 따라서 매실박 메탄올 추출물의 항균물질은 항균활성이 높고, 항균s spectrum이 광범위할 뿐 아니라, 높은 온도 및 넓은 범위의 pH에 안정하여 이상적인 천연 항균제로서의 개발가능성을 제시하였다. 아울러, 매실박 메탄올 추출물의 주요 항균작용은 세포막 perturbation에 기인한 것으로 생각되었다.

• Smart Structures and Systems
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• 제19권1호
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• pp.39-46
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• 2017

Finite element model updating is very effective procedure to determine the uncertainty parameters in structural model and minimize the differences between experimentally and numerically identified dynamic characteristics. This procedure can be practiced with manual and automatic model updating procedures. The manual model updating involves manual changes of geometry and analyses parameters by trial and error, guided by engineering judgement. Besides, the automated updating is performed by constructing a series of loops based on optimization procedures. This paper addresses the ambient vibration based finite element model updating of long span reinforced concrete highway bridges using manual model updating procedure. Birecik Highway Bridge located on the $81^{st}km$ of Şanliurfa-Gaziantep state highway over Firat River in Turkey is selected as a case study. The structural carrier system of the bridge consists of two main parts: Arch and Beam Compartments. In this part of the paper, the arch compartment is investigated. Three dimensional finite element model of the arch compartment of the bridge is constructed using SAP2000 software to determine the dynamic characteristics, numerically. Operational Modal Analysis method is used to extract dynamic characteristics using Enhanced Frequency Domain Decomposition method. Numerically and experimentally identified dynamic characteristics are compared with each other and finite element model of the arch compartment of the bridge is updated manually by changing some uncertain parameters such as section properties, damages, boundary conditions and material properties to reduce the difference between the results. It is demonstrated that the ambient vibration measurements are enough to identify the most significant modes of long span highway bridges. Maximum differences between the natural frequencies are reduced averagely from %49.1 to %0.6 by model updating. Also, a good harmony is found between mode shapes after finite element model updating.

• 한국컴퓨터정보학회논문지
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• 제26권10호
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• pp.9-17
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• 2021

인간은 사회적인 동물로서, 대화로써 정보를 얻거나 사회적인 교류를 해왔다. 대화는 두 사람 이상의 작은 모임에서 서로 말을 편하게 주고받는 것으로, 한 사람이 다른 사람에게 가지는 감성에 따라 그 말의 분위기가 달라질 수 있다. 영화에서 인물들과 인물들이 펼치는 이야기는 중요한 요소로 작용하며, 인물들 간의 관계는 이야기와 인물 간의 대사를 이해하는데 꼭 필요하다. 그러나 이런 정보를 영화에서 자동으로 추출하는 방법은 아직까지 연구되지 않아서 관객들에게 제공되고 있지 못하고 있다. 따라서, 영화 속 양상을 자동으로 분석하는 모델이 필요하다. 본 논문에서는 딥 러닝 기법을 활용하여 각 영화 등장 인물들 간의 감성을 측정하여 영화 속 인물들 간의 관계를 효과적으로 분석하는 방법을 제안한다. 제안 방법은 먼저 영화 대본으로부터 주요 인물들을 추출하고, 주요 인물들 간의 대화를 효과적으로 찾는다. 그런 다음, 주요 인물들 간의 관계를 분석하기 위하여, 감성 분석을 수행하여 전체 시간 간격 내 대사의 위치에 따라 가중치를 부여하고 점수를 수집한다. 또한, 실데이터를 이용한 실험을 통하여 제안 기법이 효과적으로 영화 등장 인물들 간의 감성을 분석할 수 있음을 보인다.

• 한국해양바이오학회지
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• 제13권2호
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• pp.94-103
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• 2021

Here, we evaluated the anti-glycation effects and renal protective properties of 70% (v/v) ethanolic extract of Colpomenia sinuosa (CSE) against AGEs -induced oxidative stress and apoptosis at different concentrations (1, 5, and 20 ㎍/mL). At 20 ㎍/mL, CSE showed that anti-glycation activities via the inhibition of AGE formation (51.1%), inhibition of AGEs-protein cross-linking (61.7%), and breaking of AGEs-protein cross-links (33.3%), were significantly (###p < 0.001 vs. non-treated group) lower than the nontreated group. Methylglyoxal (MGO) significantly (***p < 0.001) reduced cell viability (24.4%) and increased reactive oxygen species (ROS) level (642.3%), MGO accumulation (119.4 ㎍/mL), and apoptosis (55.0%) in mesangial cells compared to the nontreated group. Pretreatment with CSE significantly (###p < 0.001) increased cell viability (57.8%) and decreased intracellular ROS (96.5%), MGO accumulation (80.0 ㎍/mL), and apoptosis (22.6%) at 20 ㎍/mL. Additionally, we confirmed intracellular AGEs reduction by CSE pretreatment. Consequently, our results suggest that CSE is a good source of natural therapeutics for managing diabetic complications by the antiglycation effect and renal protective activity against MGO-induced oxidative stress.

• 생약학회지
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• 제52권4호
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• pp.242-250
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• 2021

Artemisia frigida Willd (AW, Fringed sagewort), which is widespread in Mongolia, is a well-known medicinal plant as a member of the Compositae family. This study aims to explore the gastroprotective effect of water extract of AW on 150 mM HCl/60% ethanol-induced acute gastritis in 5 week old male ICR mice. Total polyphenols, total flavonoid contents, and anti-oxidant activity in vitro in AW were evaluated. First, the gross area of gastric mucosal damage was measured. Then western blot analysis was conducted to determine the possible mechanisms of action underlying the effects of AW. AW administration decreased gastric mucosal damage. Moreover, the group with AW treatment effectively inhibited nicotinamide adenine dinucleotide phosphate (NADPH) oxidase expression associated with oxidative stress. AW treatment enhanced an anti-oxidant effect through the increase of anti-oxidant proteins. Besides, the increased expressions of inflammatory cytokines induced by nuclear factor-kappa B (NF-κB) activation are alleviated through AW treatment. Taken together, AW exerted a gastroprotective effect against gastric mucosal damage. These results indicate that AW could have the potential used as a natural therapeutic drug for the treatment of acute gastritis.

• 한국식품영양학회지
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• 제34권5호
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• pp.423-429
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• 2021

Barley's nutritional value as a health food is increasing due to its excellent nutritional functionality. In this study, the levels of β-glucan, total polyphenols, and total flavonoids were analyzed in the ethanol extracts of different barley cultivars (Hinchalssal, Heuksoojeongchal, Betaone, Ganghochung, and Saechalssal). Also, the free radical scavenging abilities of 2,2-diphenyl-1-picryl-hydrazil (DPPH) and 2,2'-azino-bis-3-ethylbenzo-thiaxoline-6-sulfonic acid (ABTS) were measured to determine their antioxidant activity. The results confirmed that Betaone extract contained highly activefunctional components and exhibitedantioxidant activity. Next, we evaluated the hepatoprotective and inhibitory effects of reactive oxygen species (ROS) generated by barley ethanol extracts after inducing oxidative stress with tert-butyl hydroperoxide (tBHP) in HepG2 cells. Hinchalssal and Saechalssal extracts showed the most significant cytoprotective effect and also reduced ROS production significantly. These results suggest that Hinchalssal, Saechalssal, and Betaone represent potential natural antioxidant and hepatoprotective agents.

• Natural Product Sciences
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• 제27권3호
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• pp.187-192
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• 2021

Cordycepin is a characteristic bioactive compound of Cordyceps militaris with various beneficial effects. Cordyceps grows on both grains and insects, and the content of cordycepin varies depending on the cultivation conditions. In this study, the effect of culture conditions on the cordycepin content was analyzed and the extraction conditions were optimized. Analysis of cordycepin content in Pupae-Cordyceps found that it was highly affected by temperature in culture conditions. In the case of mycelium, it grows well at 20 and 25 ℃, but not at 30 ℃. However, the content of cordycepin was highest at 30℃ and less at 20 ℃. The fruiting body also showed a similar tendency: growth was 20 ℃ > 25 ℃ > 30 ℃, but the cordycepin content was 30 ℃ > 25 ℃ > 20 ℃. The content of cordycepin decreased after the fruiting bodies were produced. Next, extraction conditions such as solvent and time were optimized for maximum cordycepin content using response surface methodology (RSM). There was a large difference in the content of cordycepin according to the content of ethanol and the extraction temperature. Through RSM, it was confirmed that the optimum condition for extraction of cordycepin was 48.9 ℃ using 49.0% ethanol, and 160.9 mg/g extract could be obtained under this condition. In conclusion, this study suggested the optimized conditions for the cultivation and extraction of Pupae-Cordyceps for maximizing the content of cordycepin, and this may be applied to the discovery of materials using cordycepin.