• 미생물학회지
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• 제23권1호
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• pp.13-19
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• 1985

제한효소 Acc I을 정제하고 그 효소적 특성을 연구하였다. 300g(wet weight)의 Acinetobacter calcoaceticus 로부터 얻은 crude extract를 sample로 하여 ammonium sulfate fractionation을 거쳐 Heparin-agarose, DEAE-se-phades, Affi,-gel Blue, phosphoceIIulose, hydroxylapatite의 순서로 chromatography를 수행한 결고 0 .28mg의 AccI 제한효소를 얻었다. 효소의 specific activity는 mg당 $1.1{\times}10^{s}$ unit 이었다. 정제된 Acc [제한효소는 10% SDS-polyacrylamide gel electrophoresis에서 한개의 band로 나타났으며 그 분자량은 45,000~1,000이었다. 이 효소는 $MgCl_2$ 존재하에, pH 8.0에서 11.0사이에서 최대의 활성을 보였다. NaCl은 이 효소의 활성에는 필요하지 않았으나 150mN이상에서는 급격한 효소 활성의 감소가 있었다.

• 한국잡초학회지
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• 제30권2호
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• pp.68-83
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• 2010

Weedy rice (Oryza sativa L.) occurred sympatrically with other weeds and the rice crop in Malaysian rice granaries. We conducted field surveys in 2006-2008 seasons in 7 farm blocks of Selangor's North West Project, Malaysia to enlist the new biotypes of weedy rice (NBWR) and assess their spatio-temporal pattern of distribution based on quantitative and dispersion indices. No less than 16 accessions of NBWR were identified based on their special traits, viz. panicle type, pericarp colour, presence or absence of awn, seed type and degree of grain shattering. The NBWR accessions exhibited a combination of morphological traits from open panicle, grain with awns, red pericarp, short grain type, and degrees of grain shattering. Others mimic commercial rices with close panicle, awnless grains, white pericarp, long or short grain-type. Invariably, the NBWRs mimic and stand as tall as cultivated rice namely MR219, MR220, or MR235 and these NBWR accessions stand among equals morphologically vis-a-vis the commercial rice varieties. Most accessions displayed varying degrees of grain shattering in excess of 50%, except Acc9 and Acc12. The seasonal dynamics of on the prevalence of dominant NBWR accessions were also displaying significant differences among farm blocks. While Bagan Terap farm block, for example, did not record any measurable changes in the dominant NBWR accessions over seasons, the Sungai Leman farm block recorded measurable season-mediated changes in the dominant NBWR accessions. Sungai Leman started with NBWR Acc3, Acc4, Acc5, Acc7, Acc8, and Acc12 in season 1 of 2006/2007, but no measurable records of Acc3 and Acc5 were shown in season 2 of 2007. In season 3 of 2007/2008, only Acc8 and Acc12 prevailed in the farm block. In Sawah Sempadan farm block, season 3 of 2007/2008 showed much reduced prevalence of NBWRs leaving only Acc8 and Acc12. Most accessions registered clump or under-dispersed spatial distribution pattern based on quantitative indices: variance-to-mean ratio (VMR) and Lloyd's patchiness values. The dynamics on the extent of infestation and prevalence of dominant NBWR accessions registered both season- and farm-block mediated differences. Most accessions showed VMR >1 thus indicative of having a clump or clustered spatial distribution, as exemplified by Acc3, Acc4, Acc7, Acc8 and Acc12 in all farm blocks throughout three seasons. Some accessions have either random or uniform distribution in a few farm blocks. The Acc8 has the highest population counts based on important value index, followed by Acc12, and both were the most dominant accession while Sawah Sempadan was the worst farm block infested by NBWR compared to other farm blocks. These results were discussed in relation with the current agronomic and weed management practices, water availability and extension services in the granary.

• Journal of Microbiology and Biotechnology
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• 제25권7호
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• pp.1119-1128
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• 2015

1-Aminocyclopropane-1-carboxylate (ACC) deaminase, which is encoded by some bacteria, can reduce the amount of ethylene, a root elongation inhibitor, and stimulate the growth of plants under various environmental stresses. The presence of ACC deaminase activity and the regulation of ACC in several rhizospheric bacteria have been reported. The nitrogen-fixing Pseudomonas stutzeri A1501 is capable of endophytic association with rice plants and promotes the growth of rice. However, the functional identification of ACC deaminase has not been performed. In this study, the proposed effect of ACC deaminase in P. stutzeri A1501 was investigated. Genome mining showed that P. stutzeri A1501 carries a single gene encoding ACC deaminase, designated acdS. The acdS mutant was devoid of ACC deaminase activity and was less resistant to NaCl and NiCl₂ compared with the wild-type. Furthermore, inactivation of acdS greatly impaired its nitrogenase activity under salt stress conditions. It was also observed that mutation of the acdS gene led to loss of the ability to promote the growth of rice under salt or heavy metal stress. Taken together, this study illustrates the essential role of ACC deaminase, not only in enhancing the salt or heavy metal tolerance of bacteria but also in improving the growth of plants, and provides a theoretical basis for studying the interaction between plant growth-promoting rhizobacteria and plants.

• 감성과학
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• 제23권2호
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• pp.103-120
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• 2020

본 연구에서는 운전 시뮬레이션을 이용하여 적응형 정속 주행(adaptive cruise control: ACC) 시스템에 대한 운전자의 신뢰 및 도로 혼잡도가 운전자의 작업부하와 상황인식에 미치는 효과를 알아보았다. ACC 시스템에 대한 운전자의 신뢰는 ACC 시스템이 정상 작동하는 조건과 시스템이 오작동하는 조건을 통해 신뢰상승 집단과 신뢰감소 집단으로 구분하였다. 도로 혼잡도는 운전자 차량 주변의 차량 수로 수준을 조작하였다. ACC 시스템에 대한 신뢰와 도로 혼잡도를 달리한 네 가지의 실험 조건 각각에 대해 운전자들의 작업부하와 상황인식을 측정하였다. 본 연구의 결과를 요약하면 다음과 같다. 먼저 ACC 시스템에 대한 신뢰감소 집단은 신뢰상승 집단에 비해 이 시스템의 사용으로 인한 운전부담 경감이나 안전운전 확보 등을 포함한 측정 항목 모두에서 시스템에 대한 신뢰 점수가 유의하게 더 낮았다. 둘째, ACC 시스템에 대한 신뢰감소 집단은 신뢰상승 집단에 비해 이차과제에서 더 느린 반응시간을 보였고, 시스템 사용에서의 주관적인 작업부하 수준도 더 높게 평정하였다. 셋째, 이와는 대조적으로 운전자들의 운전상황에 대한 상황인식은 ACC 시스템 신뢰감소 집단이 신뢰상승 집단보다 유의하게 더 우수하였다. 본 연구의 결과들은 ACC 시스템에 대한 신뢰가 운전 중에 수행하는 다양한 정보처리에 영향을 미칠 수 있음을 보였는데, 이것은 자동화된 운전보조 시스템의 설계에서 사용자의 시스템에 대한 신뢰가 중요한 변인으로 고려되어야 한다는 것을 시사한다.

• International Journal of Automotive Technology
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• 제7권5호
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• pp.603-608
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• 2006

As an important and relatively easy to implement technology for realizing Intelligent Transportation Systems(ITS), Adaptive Cruise Control(ACC) automatically adjusts vehicle speed and distance to a preceding vehicle, thus enhancing driver comfort and safety. One of the key issues associated with ACC development is usability and user acceptance. Control parameters in ACC should be optimized in such a way that the system does not conflict with driving behavior of the driver and further that the driver feels comfortable with ACC. A driving simulator is a comprehensive research tool that can be applied to various human factor studies and vehicle system development in a safe and controlled environment. This study investigated driving behavior with ACC for drivers with different driving styles using the driving simulator. The ACC simulation system was implemented on the simulator and its performance was evaluated first. The Driving Style Questionnaire(DSQ) was used to classify the driving styles of the drivers in the simulator experiment. The experiment results show that, when driving with ACC, preferred headway-time was 1.5 seconds regardless of the driving styles, implying consistency in driving speed and safe distance. However, the lane keeping ability reduced, showing the larger deviation in vehicle lateral position and larger head and eye movement. It is suggested that integration of ACC and lateral control can enhance driver safety and comfort even further.

• Smart Structures and Systems
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• 제17권3호
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• pp.391-411
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• 2016

This study investigates the mode identifiability of a multi-span cable-stayed bridge in terms of a benchmark study using stabilization diagrams of a system model identified using stochastic subspace identification (SSI). Cumulative contribution ratios (CCRs) estimated from singular values of system models under different wind conditions were also considered. Observations revealed that wind speed might influence the mode identifiability of a specific mode of a cable-stayed bridge. Moreover the cumulative contribution ratio showed that the time histories monitored during strong winds, such as those of a typhoon, can be modeled with less system order than under weak winds. The blind data Acc 1 and Acc 2 were categorized as data obtained under a typhoon. Blind data Acc 3 and Acc 4 were categorized as data obtained under wind conditions of critical wind speeds around 7.5 m/s. Finally, blind data Acc 5 and Acc 6 were categorized as data measured under weak wind conditions.

• 한국산학기술학회논문지
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• 제21권1호
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• pp.457-467
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• 2020

세계적으로 환경문제에 관한 우려가 급증하여, 세계 각국이 온실가스 연비 규제를 강화하고 있다. 연비향상을 위해 첨단 운전자 지원 시스템을 이용한 연구를 통하여, 운전자의 편의를 위해 다양한 첨단 운전자 지원 시스템을 개발하고 있다. 그중 ACC, LKAS, AEB 등의 시스템에 대한 연구가 활발하다. ACC의 목적은 차량의 종 방향 속도와 거리를 제어하고 운전자의 부하를 최소화하여 사고 예방과 방지에 유용한 시스템으로 평가되고 있다. 이러한 관점에서 본 논문은 선행연구에서 제안한 국내도로 환경을 고려한 시나리오와 거리에 대한 함수로 안전성을 평가할 수 있는 수학적 방법을 활용한다. 또한, 제안한 시나리오를 기반으로 시뮬레이션과 실도로 실차시험을 진행한 뒤, 이론수식을 활용한 이론 계산값, 시뮬레이션과 실도로 실차시험의 상대거리의 비교분석을 통하여 ACC의 기능적인 안전성을 검증하고자 한다. 이러한 방법을 통하여 많은 회사들이 ACC의 개발 단계에서 시나리오, 수식, 시뮬레이션을 활용하여 안전성 평가방법으로 활용할 수 있을 것으로 예상된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1469_1470
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• 2009

기존의 링크박스는 대부분 직매식으로 수침투 방지를 위해 케이스와 뚜껑 사이에 가스켓을 넣고 볼트로 체결하는 방식으로 사용하여 왔다. 이는 링크박스 유지보수 시 매번 볼트를 체결하고 해체하는 작업이 반복되어 현장 작업성이 떨어졌다. 이에 링크박스를 지상에 설치하며, 볼트의 사용을 최소화함으로써 유지보수 시 작업이 용이한 케비넷형 링크박스를 개발하였으며, 개발된 제품에 대해 전기적, 기계적 성능 시험을 수행하여 그 성능을 검증하였다.

• 한국식품영양과학회지
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• 제34권10호
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• pp.1531-1535
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• 2005

C. militaris 동충하초의 기능성을 규명하기 위하여 당대사 관련 효소인 GK, PDH 및 ACC 활성을 측정하였다. C. militaris에서 추출된 CM-A와 CM-B는 GK와 PDH 및 ACC 효소에 대하여 대조군에 비해 높은 활성을 나타냈으며, CM-B 보다는 CM-A에서 유의적으로 높은 활성 증가를 나타냈다(p < 0.05). 간세포내 당질 관련 호소의 활성은 CM-A와 CM-B 분획물의 혼합 비율에 영향을 받는 것으로 나타났는데 활성이 높은 CM-A의 비율이 커질수록유의적으로 높은 활성 증가를 나타냈다. GK와 ACC는 단일 상태의 CM-A 보다는 혼합된 상태일 때 활성이 증가하였지만, PDH는 혼합된 상태보다는 CM-A 단독일 때 가장 높은 활성을 나타냈다. 결론적으로 C. miliaris는 GK, PDH 및 ACC 등의 효소 활성을 증가시킴으로써 혈중 포도당의 상승을 억제하며 이로 인해 항당뇨 작용을 한다고 판단된다.

• 자동차안전학회지
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• 제14권2호
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• pp.57-69
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• 2022

Recently, as interest in self-driving cars has increased worldwide, research and development on the Advanced Driver Assist System is actively underway. Among them, the purpose of Adaptive Cruise Control (ACC) is to minimize the driver's driving fatigue through the control of the vehicle's longitudinal speed and relative distance. In this study, for the research of the ACC test in the real environment, the real-road test was conducted based on domestic-road test scenario proposed in preceding study, considering ISO 15622 test method. In this case, the distance measurement method using the dual camera was verified by comparing and analyzing the result of using the dual camera and the result of using the measurement equipment. As a result of the comparison, two results could be derived. First, the relative distance after stabilizing the ACC was compared. As a result of the comparison, it was found that the minimum error rate was 0.251% in the first test of scenario 8 and the maximum error rate was 4.202% in the third test of scenario 9. Second, the result of the same time was compared. As a result of the comparison, it was found that the minimum error rate was 0.000% in the second test of scenario 10 and the maximum error rate was 9.945% in the second test of scenario 1. However, the average error rate for all scenarios was within 3%. It was determined that the representative cause of the maximum error occurred in the dual camera installed in the test vehicle. There were problems such as shaking caused by road surface vibration and air resistance during driving, changes in ambient brightness, and the process of focusing the video. Accordingly, it was determined that the result of calculating the distance to the preceding vehicle in the image where the problem occurred was incorrect. In the development stage of ADAS such as ACC, it is judged that only dual cameras can reduce the cost burden according to the above derivation of test results.