• 응용통계연구
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• 제16권2호
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• pp.321-333
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• 2003

자기조직화 지도(SOM)은 T. 코호넨의 주도하에 개발된 비지도 학습 신경망 모형이다. 그 동안 패턴인식과 문서검색 분야에 주로 응용되어 왔기 때문에 통계학 분야에서는 덜 알려졌으나, 최근 K-평균 군집화에 대한 대안적 데이터 마이닝 기법으로 활용되기 시작하였다. 본 연구에서는 SOM의 한 버전인 PC-SOM(주성분 자기조직화 지도)을 제안하고 활용 예를 제시하고자 한다. PC-SOM은 1차원적 SOM 알고리즘을 반복 수행하여 2차원, 3차원 등의 SOM을 얻는 방법이기 때문에 기존 SOM과는 달리 사전 Map의 크기를 확정할 필요가 없다. 또한, 기존 SOM에 비하여 향상된 시각화를 가능하게 한다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2002년도 추계종합학술대회
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• pp.378-381
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• 2002

본 논문에서는 근전도(EMG) 신호를 이용하여 휴먼보조 장치나 원격 제어에 활용할 수 있는 가상 로봇 팔 제어 방식을 제안한다. 4개의 표면 전극에서 근전도 신호를 측정하여 SOM과 LVQ를 이용하여 동작을 분류하는 시스템이다. 인터페이스 프로그램은 PC 상에서 구성하였다. 제안한 방식의 실험결과 94%의 분류 성공률을 얻었다.

• Journal of Forest and Environmental Science
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• 제39권2호
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• pp.73-80
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• 2023

Little is known of the life history of Garcinia kola; the objective of this study, therefore, was to assess the fruiting age and tree size of the species in a coastal humid tropical climate plantation condition. A total 103 trees were used in the study viz; 80 ten-year-old trees at reproductive maturity onset and 13 thirty-year-old trees with several cycles of reproduction that constitute two independent variables. Data collected were age of onset of flowering and size at reproductive maturity onset. Relative size at reproductive maturity onset (RSOM) was estimated as size at reproductive maturity onset (SOM) divided by asymptotic maximal size (AMS). Data analysis was conducted using pairwise t-test and principal component analysis (PCA). Reproductive maturity onset (flowering) was recorded in the ten-year-old stand eight (8) years after planting. Mean size at reproductive maturity onset (SOM) was height 5.32±1.7 m, dbh 0.11±0.03 m, total number of branches was 29.6±7.3, crown depth 5.24±1.05 m, crown diameter was 4.78±0.7 m, branch diameter 0.098±0.01 m, leaf length 0.13±0.02 m, leaf breadth 0.37±0.01 m, twig length 0.35±0.11 m and leaf per twig 6±0.84 and asymptotic maximal size (AMS) was height 19.85±0.76 m, dbh 0.95±0.09 m, total number of branches 62±5, crown depth 18.83±0.7 m, crown diameter 12.5±1.64 m, branch diameter 0.5±1.6 m, leaf length 0.16±0.023 m, leaf breadth 0.45±0.12 m, twig length 0.37±0.11 m and leaf per twig 19±7.5. Pairwise t-test analysis showed there was significant differences between SOM and AMS in all growth factors except leaf length, leaf breadth, and twig length. Highest relative size at reproductive maturity onset (RSOM) was recorded in leaf length 0.82, twig length 0.82, and leaf breadth 0.80, while, the lowest was branch diameter 0.11. Four components out of the total of eleven were extracted to explain the relationship in RSOM: Principal component one (PC1) explained 37.23%; PC2 26.4%, PC3 22.73%, and PC4 13.64%.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2013년도 춘계 종합학술대회 논문집
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• pp.253-254
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• 2013

In the preceding studies, an analysis of Saga Prefectural sightseeing information by a self-organizing map (SOM) has been tried. And recent development on information and communication technology (ICT) will help us to access any results via the mobile devices easily. Then, in order to realize this basic idea, development of an application for mobile devices is investigated through some preliminary computer simulations on the standard desktop PC in this article.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.252-252
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• 2012

It is widely accepted that short exciton diffusion lengths of organic semiconductors with respect to the film thickness limit the charge (hole and electron) separation before excitons recombination in organic photovoltaic (OPV) cells. Therefore the efficient absorption of incident light within the thin active organic layer is of great importance to improve the power conversion efficiency (PCE) of the cells. In this work, we fabricated 2-dimensionally (2D) nano-patterned poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOST:PSS) layers using capillary phenomenon and nano-imprinting technology at the scale of several hundred nanometers. This 2D nano-patterned PEDOT:PSS layer exerted photonic crystal effect such as redirection of light paths and variation of light intensity at specified wavelengths. It is also expected that the consequently alternated light pass lengths and intensities change the absorption properties of zinc phthalocyanine (ZnPc) thin films grown on top of the nano-patterned PEDOT:PSS layer. The influence of conductivity and thickness of the PEDOT:PSS layer on the absorption properties of ZnPc thin films were also investigated.

• International Journal of Contents
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• 제9권3호
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• pp.15-18
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• 2013

In the preceding studies, an analysis of Saga Prefectural sightseeing information by a Self-Organizing Map (SOM) has been tried. And recent development on Information and Communication Technology (ICT) will help us to access any results via the mobile devices easily. This is why the mobile devices, e.g., smartphones and tablet computers, have an operating system installed, and we can improve their functions by downloading any applications on the Web. Then, in order to realize this basic idea, development of an application for the mobile devices is investigated through some computer simulations on the standard desktop PC in this paper. As a result, it is found that i) a developed feature map is useful to identify some candidate topics, ii) a touchscreen is suitable to show the feature map, and iii) arrangement of the feature map can be modified based on our interests. Then, it is concluded that the proposed idea seems to be applicable, even though further consideration is required to brush it up.

• 한국자원식물학회지
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• 제33권6호
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• pp.551-557
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• 2020

In this study, we were performed to elucidate the antioxidant and anticancer activity by leaves extracts from Acer tegmentosum (AT-L). In DPPH, ABTS radical scavenging activity, the AT-L revealed the high scavenging activity. Especially, the AT-L measured the highest ABTS radical scavenging activity, which is higher than ascorbic acid. The types of human cancer cells for evaluating the anticancer activity were colorectal cancer (SW480), prostate cancer (PC-3), breast cancer (MCF-7), pancreatic cancer (AsPC-1), lung cancer (A549) and liver cancer (HepG2). Human cancer cell viability was measured using MTT assay. Treatment of the AT-L decreased the cell viability and induced apoptosis in SW480 cells. These results suggest that extracts of the AT-L can be used as supplementary material for developing the natural antioxidant and anticancer drug for human cancer cells.

• Journal of Plant Biotechnology
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• 제48권2호
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• pp.106-114
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• 2021

본 연구에서는 갈매나무과에 속하는 Rhamnus yoshinoi (RY, 짝자래나무) 가지 부위의 70% 에탄올 추출물을 이용하여 전립선암세포의 항암 활성을 규명하고자 하였다. 짝자래 나무 가지 추출물을 전립선암 세포 PC-3에 처리하여 β-catenin과 TCF4의 단백질 수준 감소를 확인하였다. 이후, β-catenin과 TCF4의 mRNA 발현을 조사한 결과 β-catenin은 감소하지 않았고, TCF4는 감소하였다. 이를 통해, β-catenin mRNA의 발현에는 영향이 없지만, TCF4 mRNA 발현은 억제하는 것으로 나타났다. 단백질 분해효소억제제인 MG132를 처리한 전립선암 세포 PC-3에서 단백질 수준 확인을 통해 β-catenin의 단백질 분해를 유도할 수 있음을 확인하였다. 또한 전립선암 세포 PC-3에서 짝자래나무 가지 추출물의 GSK-3β 유도 β-catenin 단백질 분해 Kinase 구명과 β-catenin 인산화에 영향을 미치는 것을 확인하였다. 이상의 연구 결과로 짝자래나무 가지 추출물은 GSK-3β 의존성 Wnt/β-catenin 단백질의 분해를 통해 전립선암의 생육 억제와 관련이 있는 것으로 확인된다. 또한 짝자래나무 가지 추출물에서 항암활성과 관련된 활성물질이 있는 것으로 확인되었다. 본 결과는 전립선암의 항암제 개발을 위한 소재로 짝자래나무 가지 추출물의 활용이 가능할 것으로 판단된다.