서울전파천문대(SRAO) 6M 망원경의 ON-THE-FLY 관측 시스템 구축

강현우,변도영,박용선,Kang, Hyun-Woo,Byun, Do-Young,Park, Yong-Sun 한국천문학회 2005 天文學論叢 Vol.20 No.1

On-The-Fly (OTF) observation method is developed for the efficient use of 6 M radio telescope at Seoul Radio Astronomy Observatory (SRAO). This technique, in which data and information of antenna position are recorded synchronously while driving a telescope regularly and rapidly across a field, provides more efficient use of telescope time and better calibration of the acquired data than the traditional point-to-point observation method does. For the realization of the method, we (1) added RT-Linux modules to the existing operating system, (2) replaced digital voltmeter with voltage-to-frequency converter, and (3) modified many SRAO observation programs. By observing Moon and G78.2+2.7 using this method and comparing them with previous observations, we verify the successful operation and efficiency of the OTF observation mode.

코히어런스 영향과 시간에 따른 실측 데이터의 합성 효과 실험

강현우,Kang Hyun-Woo 한국음향학회 2006 韓國音響學會誌 Vol.25 No.4

소나 시스템의 표적 탐지 성능을 향상시키기 위한 방법으로 합성 어퍼쳐 소나 (SAS : Synthetic Aperture Sonar)에 대한 연구와 실험이 이루어지고 있다. 본 논문에서는 한국 근해에서 견인 어레이를 통해 획득한 데이터를 이용하여 합성을 하는 실험을 수행하였다. 실제 상황에서 형상이 왜곡된 견인 어레이의 형상을 추정하여 왜곡을 보상해주고, 대표적인 합성 기법인 ETAM 기법과 같이 어퍼쳐 영역에서 합성을 하는 실험을 하였다. 함속이 일정하게 유지되는 구간의 데이터에 대해 실험한 결과 표적 신호의 코히어런스가 유지되는 약 1분여 동안 SNR이 높아지고 주엽 (main lobe)의 빔폭이 좁아지는 합성 효과가 나타남을 알 수 있었다. 또한 시간이 지남에 따라서도 합성 효과가 지속적으로 나타남을 확인하였다. Various research and development on Synthetic Aperture Sonar technique is under way to enhance bearing resolution of a SONAR system. In this paper, we estimated perturbed array shapes, and compensated distortion by using estimated away shapes and synthesized arrays in aperture domain such as an ETAM technique. As experimental data, we used the one obtained from towed array in neighboring waters of the Korean peninsula. Through simulation on data where tow-ship speed is maintained at a constant level, we confirmed that synthesis effect of increasing SNR and narrowed beam width of main lobe was consistently demonstrated for about 1 minute when coherence of target signal was maintained. Also, we showed that the synthesis effect with respect to time was constantly maintained.

FM 라디오 환경에서의 실시간 음악 판별 시스템 구현

강현우,Kang, Hyun-Woo 한국정보처리학회 2009 정보처리학회논문지B Vol.16 No.2

본 연구에서는 GMM 기반의 음성/음악 판별 방법을 응용하여 FM 라디오 방송에서 순수한 음악 구간만을 판별하는 시스템을 구현하였다. 본 시스템에서는 음성, 음악, 광고 음악, 기타 여러 가지 사운드가 혼합되어 있는 오디오 방송 프로그램에서 순수한 음악만을 판별하여 자동으로 저장하고자 한다. 음악의 시작 부분과 끝 부분을 보다 정교하게 검출하고자 순수한 음악으로 판별된 구간의 시작 부분과 끝 부분에 대해 후처리 과정을 추가하였다. PC 환경에서 FM 라디오 방송을 이용하여 구현된 시스템을 실시간으로 테스트한 결과 우수한 성능을 보임을 확인하였다. 또한 SoC 구현을 고려하여 고정소수점 연산을 수행한 결과 3MIPS 이하의 적은 연산량으로 부동소수점 연산일 때와 동일한 결과를 얻을수 있었다. This paper proposes a Gaussian mixture model(GMM)-based music discrimination system for FM broadcasting. The objective of the system is automatically archiving music signals from audio broadcasting programs that are normally mixed with human voices, music songs, commercial musics, and other sounds. To improve the system performance, make it more robust and to accurately cut the starting/ending-point of the recording, we also added a post-processing module. Experimental results on various input signals of FM radio programs under PC environments show excellent performance of the proposed system. The fixed-point simulation shows the same results under 3MIPS computational power.

LED 방열모듈 소형화를 위한 환경 조건 연구

강현우(Hyun woo Kang),이혁민(Hyuk min Lee) 한국자동차공학회 2019 한국자동차공학회 학술대회 및 전시회 Vol.2019 No.11

걸리 침식 평가를 위한 SATEEC, nLS, USPED 연계 시스템의 개발 및 적용

강현우 ( Hyun Woo Kang ),박윤식 ( Youn Shik Park ),김남원 ( Nam Won Kim ),옥용식 ( Yong Sik Ok ),장원석 ( Won Seok Jang ),류지철 ( Ji Chul Ryu ),김기성 ( Ki Sung Kim ),임경재 ( Kyoung Jae Lim ) 한국물환경학회 2010 한국물환경학회지 Vol.26 No.4

팽이버섯 추출물의 항산화 및 항염증 활성

강현우(Hyun Woo Kang) 한국식품영양과학회 2012 한국식품영양과학회지 Vol.41 No.8

The potential antioxidant and anti-inflammatory effect of water and ethanol extracts from Flammulina velutipes (Curtis) Singer (FVS) on hydrogen peroxide (H2O2) and LPS-induced oxidative damage in PC-12 and RAW264.7 cells were investigated. The DPPH radical scavenging activities of the water extract from FVS was the highest, and the 50% inhibitory concentration value was 0.388 mg/mL. Also, the antioxidant activities of water and ethanol extracts were determined by ferric reducing antioxidant power, 2,2"-azino-bis-(3-ethybenzothiazoline-6-sulphonic acid) radical scavenging activity. In addition, water extract from FVS showed a strongly inhibitory effect on lipid peroxidation by measuring ferric thiocyanate values. The water extract decreased cell apoptosis in PC-12 cells against H2O2-induced oxidative damage. In addition, FVS extracts exhibited the strongest nitric oxide (NO) inhibition activity. It was also found that FVS extract inhibited LPS-induced iNOS and COX-2 expression in RAW264.7 cells. The findings of the present study suggest that extracts of FVS exhibit anti-oxidative and anti-inflammatory activity against oxidative stress and/or stimulated cells.

환경부 8일 유량,수질 자료를 이용한 SWAT 자동보정 모듈 개선 및 적용 평가

강현우 ( Hyun Woo Kang ),류지철 ( Ji Chul Ryu ),강형식 ( Hyung Sik Kang ),최재완 ( Jae Wan Choi ),문종필 ( Jong Pil Moon ),최중대 ( Joong Dae Choi ),임경재 ( Kyoung Jae Lim ) 한국물환경학회 2012 한국물환경학회지 Vol.28 No.2

Soil and Water Assessment Tool (SWAT) model has been widely used in estimation of flow and water quality at various watersheds worldwide, and it has an auto-calibration tool that could calibrate the flow and water quality data automatically from thousands of simulations. However, only continuous measured day flow/water quality data could be used in the current SWAT auto-calibration tool. Therefore, 8-day interval flow and water quality data measured nationwide by Korean Ministry of Environment (MOE) could not be used in SWAT auto-calibration even though long-term flow and water quality data in the Korean Total Maximum Daily Load (TMDL) watersheds available. In this study, current SWAT auto-calibration was modified to calibrate flow and water quality using 8-day interval flow and water quality data. As a result of this study, the Nash and Sutcliffe Efficiency (NSE) values for flow estimation using auto-calibration are 0.77 (calibration period) and 0.68 (validation period), and NSE value for water quality (T-P load) estimation (using the 8-day interval water quality data) is 0.80. The enhanced SWAT auto-calibration could be used in the estimation of continuous flow and water quality data at the outlet of TMDL watersheds and ungaged point of watersheds. In the next study, the enhanced SWAT auto-calibration will be integrated with Web based Load Duration Curve (LDC) system, and it could be suggested as methods of appraisal of TMDL in South Korea.

LED 헤드램프 방열 설계 최적화 연구

강현우(Kang, Hyun Woo),한길원(Han Gil Won),이혁민(Lee, Hyuk min),박인흠(Park, In heum) 한국자동차공학회 2017 한국자동차공학회 학술대회 및 전시회 Vol.2017 No.11

LEDs are good light source for the automotive lamp. But it can’t be widely applied because of the high price of the LED module. Therefore this paper study a Optimization of LED Cooling module for LED headlamp

섬유질계 동시당화발효를 위한 내열성 융합 효모, Kluyveromyces marxianus CHY1612의 개발

강현우(Hyun-Woo Kang),김율(Yule Kim),박주용(Ju-Yong Park),민지호(Jiho Min),최기욱(Gi-Wook Choi) 한국생물공학회 2010 KSBB Journal Vol.25 No.6

To develop thermostable ethanol fermentative yeast strain for lignocellulosic simultaneous saccharification and fermentation, high ethanol producing yeast, Saccharomyces cerevisiae CHY1012 and thermostable yeast, Kluyveromyces marxianus CHY1703 were fused by protoplast fusion. The thermostable fusant, CHY1612 was identified as a Kluyveromyces marxianus by phenotypic and physiological characteristics, as well as molecular analysis based on the D1/D2 domains of the large subunit (26S) rDNA gene and the internally transcribed spacer (ITS) 1 + 2 regions. For lignocellulosic ethanol production, AFEX pretreated barley straw at 150℃ for 90 min was used in a simultaneous saccharification and fermentation (SSF) process using thermotolerant CHY1612. The SSF from 16% pretreated barley straw at 43℃ gave a saccharification ratio of 90.5%, a final ethanol concentration of 38.5 g/L, and a theoretical yield of 91.2%. These results show that K. marxianus CHY1612 has potential for lignocellulosic ethanol production through simultaneous saccharification and fermentation with further development of process.

Streptomyces avermitilis에서 olmA5 Gene의 Knock-out에 의한 Oligomycin 합성 억제

강현우(Hyun Woo Kang),유연우(Yeon Woo Ryu) 한국생물공학회 2009 KSBB Journal Vol.24 No.3

방선균은 다양한 생리활성 물질을 이차대사산물로 생산하는 산업적으로 매우 유용한 미생물이다. 이에 따라 많은 연구진들이 방선균에 대한 분자생물학적 연구와 산업적 이용에 대한 연구들을 수행하고 있다. 방선균 중에서도 S.avermitilis는 강력한 구충효과가 있는 avermectin을 생산 하지만, 또한 포유동물 세포의 미토콘드리아에서 산화적 인산화반응을 억제하는 oligomycin도 함께 생성된다. 따라서 S. avermitilis에서 oligomycin의 생성을 제거시키기 위하여 oligomycin synthetase gene을 disruption 시키기 위한 연구를 수행하였다. 이를 위하여 S. avermitilis로부터 cloning 한 oligomycin synthetase gene (olmA5)의 중앙부분에 apramycin resistance gene을 끼워 넣어 integration vector 로 구축한 후에 S. avermitilis의 chromosomal DNA와의 homologous recombination에 의하여 olmA5 gene의 disruption 을 유도하였다. Disruption mutants (olmA5::apra)는 PCR을 통해 olmA5 gene의 위치에 apramycin resistance gene 이 존재하는 것으로 확인하였고, 또한 HPLC 분석을 통해 oligomycin 생합성이 완전히 제거된 것임을 확인하였다. 그러나 disruption mutant (olmA5::apra)를 이용하여 avermectin 만을 생산할 수 있었으나, avermectin의 생산량에는 거의 변화가 없었다. 이러한 mutants는 산업적으로 avermectin을 생산하기 위한 균주 개량의 훌륭한 source가 될 수 있을 것이다. Streptomyces is well known for their ability to synthesize enormous varieties of antibiotics as secondary metabolites. Among them, S. avermitilis produces avermectins, a group of antiparasitic agents used in human and veterinary medicine. However, S. avermitilis also produces oligomycin, which is a potential toxic inhibitor of oxidative phosphorylation in mammalian cells. Therefore, we decided to disrupt oligomycin synthetase gene to prevent co-production of oligomycin in S. avermitilis. To create plasmid for disruption, the smallest gene of oligomycin synthetase gene cluster was obtained by PCR from S. avermitilis chromosome. Then, apramycin resistance gene was inserted in oligomycin synthetase gene for selection. After transformation of this plasmid, oligomycin synthetase gene (olmA5) in the chromosome was displaced with disruption cassette on the plasmid via homologous recombination. As a result of this gene replacement, we obtained mutants (olmA5::apra) that no longer makes the toxic oligomycin. And the mutants confirmed by PCR and HPLC analysis. However, showed no increasement of avermectin production in the mutant was observed.