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오동찬(Dong-Chan Oh),이용환(Yong-Hwan Lee) 한국통신학회 2008 韓國通信學會論文誌 Vol.33 No.3A
본 논문에서는 패킷 기반 무선 전송 시스템에서 다중 사용자 이득과 다중화 이득을 동시에 얻을 수 있는 직교 다중빔 전송 기법을 제안한다. 기존의 직교 다중빔 전송 기법에서는 채널 환경에 상관없이 항상 송신 안테나 개수만큼의 빔을 생성하였다. 하지만 이 경우 사용자 수가 적은 환경에서 다른 사용자로부터의 간섭 신호 영향으로 인해 시스템 성능이 저하되는 문제점이 발생한다. 본 논문에서는 이러한 문제점을 해결하기 위해 채널 상황에 따라 동적으로 빔의 개수를 조절하는 전송 기법에 대해 제안한다. 제안 기법은 채널의 상황에 따라 빔의 개수를 유동적으로 조절함으로써 사용자 수가 적은 환경에서도 높은 성능을 보장할 수 있다. 시뮬레이션 결과를 통해 기존 다중 직교 빔에 비해 성능 향상이 있음을 확인하였다. In this paper, we consider the use of orthogonal multiple beams (OMBs) to simultaneously achieve multi-user diversity and multiplexing gain in a packet-based wireless system. Previous OMB scheme considers the use of a fixed number of multiple beams equal to the number of transmit antennas. However, unless the number of active users is sufficiently large, the use of a fixed number of multiple beams may not provide desired performance due to the interference signal transmitted through other beams, being even worse than the use of a single beam. To alleviate this problem, we consider the adjustment of the number of beams in use to maximize the spectral efficiency according to the operating condition. Simulation results show the validity of the proposed scheme.
한국 서해안에 서식하는 주황해변해면에서 분리된 해양세균 Microbulbifer sp.으로부터 생리활성물질 비올라세인의 규명
원남일 ( Nam-il Won ),이가은 ( Ga-eun Lee ),고기범 ( Keebeom Ko ),오동찬 ( Dong-chan Oh ),나양호 ( Yang Ho Na ),박진숙 ( Jin-sook Park ) 한국미생물생명공학회(구 한국산업미생물학회) 2017 한국미생물·생명공학회지 Vol.45 No.2
오늘날 해양생물로부터 얻어진 미생물유래의 이차대사물질은 구조적, 생물학적으로 새로운 화합물의 주요한 자원이다. 그 중에서 해면동물과 미생물 관계는 생리활성 물질을 탐색하는데 가장 흥미있는 자원 중 하나로서 주목받아 왔다. 본 연구에서는 서해안 조간대에서 채집된 주황해변해면(Hymeniacidon sinapium)으로부터 분리된 세균 균주(Microbulbifer sp., 127CP-12)를 검토하였다. 배양된 세균은 자주색 색소를 생산하였으며, 색소생산의 최적 배양조건을 조사하였다. 최대 색소생산을 위한 미생물 배양조건은 25℃, pH 6.0, 3% NaCl임을 알 수 있었다. 추출용매는 에탄올과 메탄올에 비해 아세톤이 더 적절한 것으로 나타났다. 추출된 색소의 주요성분은 HLPC, NMR, MS, 그리고 UV 스펙트럼의 구조 분석을 통해 유용한 생리활성물질인 비올라세인으로 밝혀졌다. 본 연구는 해양미생물이 관여한 대사물질로부터 생리활성물질을 조사하는 연구기법을 서술함과 동시에 오늘날 변화하는 해양환경에서 해면동물과 미생물 관계의 생태학적 의의를 제시하고 있다. Microbial secondary metabolites of marine organisms are regarded as major sources of structurally and biologically novel compounds with numerous potential uses. Sponge-microbe associations are among the most interesting sources for exploring bioactive compounds. In this study, the bacterial strain Microbulbifer sp. (127CP7-12) was isolated from the Asian marine sponge Hymeniacidon sinapium collected at an inter-tidal zone on the west coast of Korea. Cultured bacteria produced a violet pigment, and optimal culture conditions for violet pigment production were investigated. Maximum production of the violet pigment from the strain culture was observed under the conditions of 25℃, pH 6.0, and 3% NaCl. Acetone provided better extraction of the pigment from fermented broth compared with ethanol and methanol. The proposed structure of the major component in the extracted crude pigment was determined via high-performance liquid chromatography, nuclear magnetic resonance, mass spectrometry, and UV spectra analyses, which showed that the metabolite was the promising bioactive compound violacein. This study describes the examination of marine bioactive materials from microbe-engaged metabolites and the ecological implica-tions of the sponge-microbe association in a changing ocean.
인삼 뿌리썩음병균에 항균활성이 있는 방선균 BK185의 분리 및 특성
김병용(Byung-Yong Kim),배문형(Mun-Hyung Bae),안재형(Jae-Hyung Ahn),원항연(Hang-Yeon Weon),김성일(Sung-Il Kim),김완규(Wan-Kyu Kim),오동찬(Dong-Chan Oh),송재경(Jaekyeong Song) 한국농약과학회 2014 농약과학회지 Vol.18 No.4
Ginseng (Panax ginseng C. A. Meyer) is an economically valuable pharmaceutical crop in Korea. In order to find promising biocontrol agents for soil-borne fungal pathogens which infect ginseng roots, we have isolated actinomycete, BK185 from soil. The isolate was investigated for the antifungal activity against to ginseng rot pathogens prior to testing genetic and chemical properties. The strain was identified as Streptomyces sp. using phylogenetic analysis based on 16S rRNA gene sequence. The most closely related species was S. sporoclivatus and S. geldanamycininus with high similarities (>99%). The isolate, BK185 showed positive reaction for PCR detection targeting biosynthetic gene clusters of PKS (Type-I polyketide synthase) and NRPS (Non-ribosomal polypeptide synthetase) genes. Major metabolite from the BK185 was analyzed by The LC/MS and identified to geldamycin, which was known to contained broad antibacterial, antifungal or anticancer activities. The results provide evidences that the strain, BK185 can be promising biocontrol agent for ginseng organic farming.
한센병 환자대상 제공 구강보건 진료 행위량 분석에 관한 연구
오동찬,성진효,김동기 대한구강보건학회 2002 大韓口腔保健學會誌 Vol.26 No.3
Leprosy is chronic infectious disease caused by Mycobacterium leprosy which has 3 to 7 years latent period, invade primarily peripheral nerve and disseminate secondly skin and other tissues such as eye, mucous membrane in upper respiratory tract, muscle, bone and testis. The purposes of this study were to analyze the frequencies and treatment times of oral health care supplies to leprotic patients and to obtain the baseline data for utilization of health project and treatment of handicapped or disabled person. The subjects were 7,491 in- and out-patients ( male : 4,511, female : 2,980) visited in the oral health care room in the Sorokdo General Hospital from 1995, May 1st to 1999, April 30th. We supplied them with oral health cares ranged from primary prevention to rehabilitation. For analysis, oral health supplies were divided into primary, second and tertiary preventive care according to preventive level for oral disease. The results were as follows: 1. Among the patients received oral health care, 70-79 aged group was occupied 35.5% and followed 60-69 aged group(28.4%) and 50-59 aged group(15.0%). 2. Total frequency of treatment were 13,454. Among them, the primary preventive care was occupied 10.1%, the secondary preventive care was 29.3% and the tertiary preventive care was 60.6%, respectively. 3. Total treatment time for oral health care was about 1,623 hours. It was consumed 197 hours(12. 1%) for the primary preventive care, 244 hours(15.0%) for the secondary preventive care and 1,182 hours(72.8%) for the tertiary preventive care, respectively. 4. Among the tertiary preventive care, 60 patients were placed with Crown & Bridge and 290 patients were wared denture including partial and complete denture.