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Diterpene Glycosides from the Aerial Parts of Inula britannica var. chinensis Regel (금불초 지상부의 Diterpene 배당체 성분)

  • Kim, Dae Keun;Kim, Jun Hyeong
    • Korean Journal of Pharmacognosy
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    • v.53 no.1
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    • pp.16-20
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    • 2022
  • Five ent-kaurane type diterpene glycosides were isolated from the aerial parts of Inula britannica var. chinensis Regel (Compositae) through repeated column chromatography. Their chemical structures were elucidated as 16β-H-ent-kauran-19-oic acid-19-O-β-D-glucopyranoside (1), 16β-hydroxy-17-acetoxy-ent-kauran-19-oic acid-19-O-β-D-glucopyranoside (2), 16β,17-dihydroxy-ent-kauran-19-oic acid-19-O-β-D-glucopyranoside (3), 16α,17-dihydroxy-ent-kauran-19-oic acid-19-O-β-D-glucopyranoside (4) and 17-O-β-D-glucopyranosyl-16β-H-ent-kauran-19-oic acid-19-O-β-D-glucopyranoside (5), respectively, by spectroscopic analysis. Among these compounds, 1-4 were isolated for the first time from this plant.

Mobility Support for IEEE 802.16j MR Networks (IEEE 802.16j 멀티 홉 릴레이 네트워크에서의 이동성 지원 방안)

  • Yang, Hyeon-Chae;Lee, Mee-Jeong
    • Annual Conference of KIPS
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    • 2007.05a
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    • pp.1199-1202
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    • 2007
  • 광대역 무선 액세스 기술에 대한 관심이 증폭되면서, IEEE 802.16 워킹그룹에서는 광대역 무선 도시권 통신망을 정의하였고, 802.16j 태스크그룹에서는 높은 전송 속도와 넓은 커버리지 제공을 위해서 802.16 시스템에 중계기를 도입하는 작업이 진행중이다. 차세대 네트워크 환경에서는 단말의 이동에도 지속적인 서비스를 제공해야 하므로 본 논문에서는 이동 단말과 기지국 간의 통신을 정의하는 802.16e의 핸드오버 절차를 확장하여 802.16j 네트워크에서 단말의 이동성을 제공하기 위한 방안을 정의하고자 한다.

DNA Barcoding of Koreanohadra kurodana (Gastropoda: Camaenidae)

  • Kang-San Kim;Jun-Sang Lee;Kuem Hee Jang
    • Animal Systematics, Evolution and Diversity
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    • v.40 no.4
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    • pp.354-358
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    • 2024
  • The land snail, Koreanohadra kurodana (Pilsbry, 1926), is endemic to Korea and was collected from Pocheon, Pyeongchang, and Taebaek in South Korea. This study describes the mitochondrial cytochrome c oxidase subunit I gene (COI) and 16S ribosomal RNA(16S) sequences of K. kurodana, followed by an analysis of the genetic distance between the genus Koreanohadra and its congeners. As a result, intra-species variation was 0.2-3.7% in COI and 0.3-4.0% in 16S. In the gene sequences of K. koreana recently reported by Japanese researchers, both COI and 16S sequences were observed to be located within the intra-species variation of K. kurodana (1.5-3.5% in COI; 0.6-4.0% in 16S). The inter-generic variation between genera Karaftohelix and Koreanohadra, closely related, was 11.8-26% and 6.2-18.7% in COI and 16S, respectively.

The Pyrolysis of Mesaconitine and Hypaconitine (Mesaconitine과 Hypaconitine의 열분해)

  • Lee, Hyun-Sun;Park, Shin-Young;Chung, Bo-Sup
    • YAKHAK HOEJI
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    • v.34 no.2
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    • pp.102-105
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    • 1990
  • The pyrolysis of mesaconitine and hypaconitine which are present as strongly toxic components in the raw aconite roots was performed. C(15)-keto pyro type compounds 1, 4 were obtained by the pyrolysis of mesaconitine and hypaconitine, respectively and structures of those compounds were determined as 16-Epi-pyromesaconitine(1) and 16-Epi-pyrohypaconitine (4) having $C(16)-{\alpha}-OCH_3$ on the basis of their spectral and chemical data.

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Implementation of a 16-Bit Fixed-Point MPEG-2/4 AAC Decoder for Mobile Audio Applications

  • Kim, Byoung-Eul;Hwang, Sun-Young
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.3C
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    • pp.240-246
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    • 2008
  • An MPEG-2/4 AAC decoder on 16-bit fixed-point processor is presented in this paper. To meet audio quality criteria, despite small word length, special design methods for 16-bit foxed-point AAC decoder were devised. This paper presents particular algorithms for 16-bit AAC decoding. We have implemented an efficient AAC decoder using the proposed algorithms. Audio contents can be replayed in the decoder without quality degradation.

Standardization Activity on IEEE 802.16m for IMT-Advanced Systems (IMT-Advanced 시스템을 위한 IEEE 802.16m 표준화 동향)

  • Im, Gwang-Jae;Yun, Cheol-Sik
    • Electronics and Telecommunications Trends
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    • v.23 no.3
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    • pp.10-18
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    • 2008
  • IEEE 802.16m은 IEEE 802.16e 시스템과의 호환성을 유지하면서 차세대 4G 이동통신 규격으로 ITU-R에 IMT-Advanced 시스템을 위한 하나의 표준 규격으로 제안 및 채택하는 것을 목표로 한다. 2007년 Stage 1 단계인 요구사항 문서를 작성하였고, 2008년에는 Stage 2 단계인 시스템 기술 문서를 작성하고 있으며, 2009년에는 Stage 3 단계인 표준 규격을 작성할 예정이다. 주요 기술적 사항은 시스템 기술 문서를 작성하는 단계에서 결정되므로 2008년은 향후 802.16m 시스템에서 기술 주도권을 확보하는 데 있어 중요한 해가 된다.