• 제목/요약/키워드: BK7

검색결과 855건 처리시간 0.032초

2단계 BK21 사업의 개요와 특징

  • 서유미
    • 대학교육
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    • 통권139호
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    • pp.7-14
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    • 2006
  • '분야별 특성화된 대학원 학과 육성을 통한 국제경쟁력 있는 석·박사급 인력 양성'을 목표로 하는 2단계 BK21 사업이 지난 1월 4일 사업 공고와 함께 막을 열었다. 2단계 BK21 사업을 통해 우리 대학이 인재 양성의 핵심기지가 되기를 기대한다.

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Description and Genomic Characteristics of Weissella fermenti sp. nov., Isolated from Kimchi

  • Jae Kyeong Lee;Ju Hye Baek;Dong Min Han;Se Hee Lee;So Young Kim;Che Ok Jeon
    • Journal of Microbiology and Biotechnology
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    • 제33권11호
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    • pp.1448-1456
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    • 2023
  • A Gram-positive, non-motile, and non-spore-forming lactic acid bacterium, designated as BK2T, was isolated from kimchi, a Korean traditional fermented vegetable food, and the taxonomic characteristics of strain BK2T, along with strain LMG 11983, were analyzed. Both strains optimally grew at 30℃, pH 7.0, and 1.0% NaCl. Cells of both strains were heterofermentative and facultatively anaerobic rods, demonstrating negative reactions for catalase and oxidase. Major fatty acids (>10%) identified in both strains were C18:1 ω9c, C16:0, and summed feature 7 (comprising C19:1 ω6c and/or C19:1 ω7c). The genomic DNA G+C contents of both strains were 44.7 mol%. The 16S rRNA gene sequence similarity (99.9%), average nucleotide identity (ANI; 99.9%), and digital DNA-DNA hybridization (dDDH; 99.7%) value between strains BK2T and LMG 11983 indicated that they are different strains of the same species. Strain BK2T was most closely related to Weissella confusa JCM 1093T and Weissella cibaria LMG 17699T, with 100% and 99.4% 16S rRNA gene sequence similarities, respectively. However, based on the ANI and dDDH values (92.3% and 48.1% with W. confusa, and 78.4% and 23.5% with W. cibaria), it was evident that strain BK2T represents a distinct species separate from W. confusa and W. cibaria. Based on phylogenetic, phenotypic, and chemotaxonomic features, strains BK2T and LMG 11983 represent a novel species of the genus Weissella, for which the name Weissella fermenti sp. nov. is proposed. The type of strain is BK2T (=KACC 22833T=JCM 35750T).

Ag$^{+}$ -Na$^{+}$이온교환법을 이용한 BK7 유리 평판형 광도파로의 특성 (Characterization of Planar Optical Waveguides by Ag$^{+}$ -Na$^{+}$ Ion Exchange in BK7 Glass)

  • 전금수;반재경
    • 전자공학회논문지D
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    • 제35D권1호
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    • pp.84-93
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    • 1998
  • Planar graded index optical waveguides have been formed by Ag$^{+}$ ion exchange in the BK7 optical glass. The experimental results of diffusion and modal characteristics of Ag$^{+}$-Na$^{+}$ exchanged BK7 glass waveguides are presented. Measurements of the mode indices have been measured. We found the relations between the process and device parameters such as the diffusion depth and the square root of the diffusion time, diffusion coefficient and diffusion temperature, and diffusion ion concentration and surface index change. A theoretical gaussian function refractive index profile matched best with the measured data for all the guided modes. The empirical relations between the process and the device parameters are derived and subsequently used to formulate a systematic procedure for fabricating singlemode and multimode waveguides.uides.

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Bhattacharyya 커널을 적용한 Centroid Neural Network (Centroid Neural Network with Bhattacharyya Kernel)

  • 이송재;박동철
    • 한국통신학회논문지
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    • 제32권9C호
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    • pp.861-866
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    • 2007
  • 본 논문은 가우시안 확률분포함수 (Gaussian Probability Distribution Function) 데이터 군집화를 위해 중심신경망 (Centroid Neural Network, CNN)에 Bhattacharyya 커널을 적용한 군집화 알고리즘 (Bhattacharyya Kernel based CNN, BK-CNN)을 제안한다. 제안된 BK-CNN은 무감독 알고리즘인 중심신경망을 기반으로 하고 있으며, 커널 방법을 이용하여 데이터를 특징공간에서 투영한다. 입력공간의 비선형 문제를 선형적으로 해결하기 위해 제안한 커널 방법인데, 확률분포 사이의 거리측정을 위해 Bhattacharyya 거리를 이용한 커널방법을 사용하였다. 제안된 BK-CNN을 영상데이터 분류의 문제에 적용했을 때, 제안된 BK-CNN 알고리즘이 Bhattacharyya 커널을 적용한 k-means, 자기조직지도(Self-Organizing Map)와 중심 신경망등의 기존 알고리즘보다 1.7% - 4.3%의 평균 분류정확도 향상을 가져옴을 확인할 수 있었다.

Synthesis of SATE Prodrug of 6'-Fluoro-6'-methyl-5'-noradenosine Nucleoside Phosphonic Acid as a New Class of Anti-HIV Agent

  • Li, Hua;Yoo, Jin-Cheol;Baik, Young-Chan;Lee, Won-Jae;Hong, Joon-Hee
    • Bulletin of the Korean Chemical Society
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    • 제31권9호
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    • pp.2514-2518
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    • 2010
  • A very simple synthetic route of a novel SATE prodrug type of 6'-fluoro-6'-methyl-5'-noradeonosine carbocyclic nucleoside phosphonic acid is described. The key fluorinated alcohol intermediate 7 was prepared from the epoxide intermediate 6a via selective ring-opening of epoxide. Coupling of 7 with $N^6$-bis-Boc-adenine under a Mitsunobu reaction followed by phosphonation and deprotection afforded the carbocyclic phosphonic acid. The chemical stability of the bis(SATE) derivative 13 was measured at neutral (pH 7.2) and slightly acidic (Milli-Q water, pH 5.5) pH. The antiviral activity test of the SATE prodrug 13 and its parent nucleoside phosphonic acid 11 were evaluated against HIV-1.

Selective Ring-opening Fluorination of Epoxide: An Efficient Synthesis of 2'-C-Fluoro-2'-C-methyl Carbocyclic Nucleosides

  • Liu, Lian-Jin;Kim, Si-Wouk;Lee, Won-Jae;Hong, Joon-Hee
    • Bulletin of the Korean Chemical Society
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    • 제30권12호
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    • pp.2989-2992
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    • 2009
  • An efficient synthetic route of novel 2′(${\alpha}$)-C-fluoro-2′(${\beta}$)-C-methyl carbocyclic nucleoside analogues is described. The key fluorinated intermediate 7 was prepared from the epoxide intermediate 5 via selective ring-opening of epoxide. Coupling of 7 with nucleosidic bases under the Mitsunobu reactions followed by deprotection afforded the target carbocyclic nucleoside analogues. The synthesized compounds were evaluated as inhibitors of the hepatitis C virus (HCV) in Huh-7 cell line in vitro.