• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.55.2-55.2
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• 2011

The final site of offshore wind power plant should be decided by comprehensive examination of various conditions such as wind resource, sea depth, geology, grid connection, social circumstance and environmental issue. Wind condition is typically regarded as the most important factor because wind energy increases in proportion to wind velocity and it directly relates to the amount of power output, efficiency of power plant and profitability. Advanced countries in the offshore wind power sector such as Denmark, UK and Germany, they are analyzing wind resource accurately by installing the meteorological mast in the ocean in order to get the optimal type of wind turbine and maximum generation efficiency. Also, it is made much of designing offshore power plant on the basis of actual measurement by met-mast and those wind farms have a chance to get the loan with reduced interest rate in project financing. In Korea, the HEMOSU-1 is installed in the ocean around Wido island to analyze wind resource of test bed of 100MW offshore wind power on october last year. This paper deals with the design and construction procedure of the first met-mast in Korea and also shows the site characteristics of test bed. Therefore, this paper will give useful information to local governments and private business sector who are trying to construct offshore wind farm and it can also be a good reference for the following projects of meteorological mast in near future.

• 한국응용과학기술학회지
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• 제29권2호
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• pp.268-277
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• 2012

폐 PVC전선의 열적분해 특성에 관한 연구를 TGA 및 고정층 반응기를 이용하여 연구하였다. 본 연구에서는 분해온도, 공기유량 및 CaO/ PVC의 비를 실험조건으로 고려하였으며, PVC전선의 열적분해과정에서 발생되는 염화수소 및 독성가스의 제거를 위한 CaO의 첨가에 대한 효과를 검증하기 위하여 PVC 전선의 열적분해 과정에서 생성되는 기상 생성물을 GC/MS를 이용하여 분석하였다. 또한 CaO의 첨가효과를 고찰하고자 액성 생성물에 대한 GC/MS을 함께 수행하였으며, 분해온도, 공기유량 및 CaO/PVC의 비에 따른 액상, 기상 및 고상 잔류물의 수율 변화를 함께 고찰하였다. 본 연구로부터 CaO의 첨가량이 증가할수록 PVC의 열적분해 과정에서 발생되는 염화수소의 제거량이 증가함을 확인하였다.

• Journal of Multimedia Information System
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• 제4권4호
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• pp.195-204
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• 2017

Mobile robots are used for years as a valuable research and educational tool in form of available open-platform designs and Do-It-Yourself kits. Rapid development and costs reduction of Unmanned Air Vehicles (UAV) and ground based mobile robots in recent years allowed researchers to utilize them as an affordable research platform. Despite of recent developments in the area of ground and airborne robotics, only few examples of Unmanned Surface Vehicle (USV) platforms targeted for research purposes can be found. Aim of this paper is to present the development of open-design USV drone with integrated multi-level control hardware architecture. Proposed catamaran - type water surface drone enables direct control over wireless radio link, separate development of algorithms for optimal propulsion control, navigation and communication with the ground-based control station. Whole design is highly modular, where each component can be replaced or modified according to desired task, payload or environmental conditions. Developed USV is planned to be utilized as a part of the system for detection and identification of marine and lake waste. Cameras mounted to the USV would record sea or lake surfaces, and recorded video sequences and images would be processed by state-of-the-art computer vision and machine learning algorithms in order to identify and classify marine and lake waste.

• 대한토목학회논문집
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• 제6권2호
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• pp.85-91
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• 1986

심해나 해상조건이 나쁜 지점에서 운영될 해양구조물의 설계시에는 파랑하중에 대한 구조물의 피로수명예측이 매우 중요하다. 본 논문에서는 랜덤파랑하중에 의해 해양구조물에 발생되는 응력의 bandwidth가 구조물의 피로수명예측 결과에 주는 영향에 대하여 연구하였다. 구조물의 동적거동해석은 비선형 점성저항력의 선형화를 통한 주파수영역해법을 사용하여 수행되었으며, 랜덤응력스펙트럼을 구하고 이를 바탕으로 피로해석을 수행하였다. 피로손상의 예측을 위한 랜덤응력 cycle의 산정은 narrow band cycle 산정법과 함께 wide band process 에 대하여 더 적정한 rainflow cycle 산정법을 사용하였다. 수심이 다른 지점에 위치한 2개의 구조물을 택하여 예제해석을 수행하였으며, 두 응력 cycle 산정법에 의해 얻은 피로해석 결과들을 비교하고 응력의 bandwidth의 영향을 분석하였다.

• Journal of Species Research
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• 제7권1호
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• pp.36-49
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• 2018

During a study to discover indigenous prokaryotic species in Korea in 2016, a total of 42 actinobacterial isolates were recovered from various environmental samples collected from natural cave, squid, sewage, sea water, trees, droppings of birds, freshwater, eelgrass, mud flat, sediment and soil. On the basis of a tight phylogenetic clade with the closest species and high level of 16S rRNA gene sequence similarity, it was shown that each isolate was assigned to independent and previously described bacterial species which were assigned to the phylum Actinobacteria. The following 42 species have not been reported in Korea: eight species in two genera n the order Corynebacteriales, 26 species of 16 genera in the Micrococcales, one species of one genus in the Micromonosporales, one species of one genus in the Propionibacteriales, four species of two genera in the Streptomycetales and two species of two genera in the Streptosporangiale. Cell morphology, Gram staining reaction, colony colors and features, the media and conditions of incubation, physiological and biochemical characteristics, origins of isolation and strain IDs of 42 unrecorded actinobacterial species are presented in the species description.

• 한국구조물진단유지관리공학회 논문집
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• 제18권5호
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• pp.19-26
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• 2014

콘크리트 방호벽 및 중앙분리대는 교량의 부속시설이지만, 슬립폼 시공과 넓은 비표면적으로 인해 초기재령 균열이 발생하기 쉽다. 본 연구에서는 대형 교량의 방호벽과 중앙분리대 콘크리트의 외관조사 및 비파괴실험을 수행하여 균열의 원인과 발생 균열의 패턴을 분석하였다. 이를 위해 시공기간을 고려하여, 건조수축, 수화열 해석이 수행되었으며, 현장의 환경조건을 고려하여 소성수축 특성을 평가하였다. 평가결과 대상구조물의 균열 원인은 철근위치에 따른 소성침하균열, 소성수축 및 건조수축에 의한 복부균열, 재료분리에 따른 상부균열로 추정할 수 있었다. 또한 균열원인과 발생 패턴을 도식화하였으며, 시공 및 재료분야에서 균열제어대책을 제안하였다. 해상위 교량에 설치하는 중앙분리대 및 방호벽 콘크리트는 환경조건 (풍속, 온도, 습도)에 매우 민감하여 초기재령균열이 쉽게 발생하므로 재료선택 및 시공방법에 신중을 기해야 한다.

• 화약ㆍ발파
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• 제15권3호
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• pp.14-19
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• 1997

Koreans have emphasized education as the primary means to reconstruct our country means to reconstruct our country after two catastrophic events-the Japanese occupation and the Korean War(1950-1953). A Strong belief- in education coupled with sheer deter-mination spurred the period of industrial and eeonomic development that started in the early 1970-'s. The "can-do" attitude of the general public was matched and aided by small S & T communities. Scientists and engineers provided the neeessary expertise to manufacture goods and process the many raw materials imported from overseas. After nearly three decades of reconst-ructing our completely devastated country, Korea has become a modern, cosmo-politan, fast-paced and dynamic country. In order to further increaser our manufac- turing capabilities and double the per-capita income by the beginning of the 21st century, we must improve productivitiy and encourage creatitivity in all sectors of our country. The S & T community's efforts in research and development. education, and interna-tional cooperation will be invaluable in determining our direction and reaching these goals. The general public is eager to peacefully unite our foreign powers since 1945. Toward that end. members of the S & T community are willing to coope-rate with our north Korean counterparts in all areas of S & T with the exception of defense related endeavors. Establi-shing scientific ties with north Korea will result in mutual economic benefit and greater regional stability in East Asia. In particular. scientists and manu-facturers in each province are eager to initiate cordial and professional relation-ships with north Korea in the hopes of securing these benefits. The Korean Federation of Science and Technology Societies(KOFST) has played an important role both in developing S & T policies, and in gostering the frowty of S & T societies. A non-governmental umbrella organization composed of over 251 professional societies, KOFST facili-tates the transfer of research outcomes and technology from research institutions to the various industries. KOFST also seeks to increase cooperation between the countries of the Pacific Rim. As evidence of that, we have pursued joint research and industrial ventures with China. Established projects include those on environmental conditions in the Yellow Sea, and improvement of aircraft manufacturing, telecommunica-tion equipment, and agricultural produ-cts. Increased cooperation between the Pacific Rim countries, particularly in S & T, would foster social and economic development for the region as a whole.

• Food Science and Biotechnology
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• 제18권5호
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• pp.1091-1095
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• 2009

The aim of this study investigated the fluctuations of 3 characters from 3 ecotypes [early ripening (ER), middle ripening (MR), and late ripening (LR)] of 20 Korean brown rice cultivars in different storage systems [time: 12 and 24 weeks, temperature: low ($10^{\circ}C$) and room ($25^{\circ}C$)]. With increase of storage time and temperature, lipoxygenase activity, and fat acidity increased, whereas germination rate was reduced. ER cultivars exhibited the highest lipoxygenase activity of $35.49{\pm}2.46$ unit/mg protein during 24 weeks storage at $25^{\circ}C$, followed by LR ($32.73{\pm}1.33$) and MR ($32.66{\pm}1.62$) cultivars. The amounts of fat acidity also were observed by the same order (ER: $20.40{\pm}2.12$>LR: $19.68{\pm}1.86$>MR: $19.64{\pm}1.35$ mg KOH/100 g). Germination rate slightly decreased with increase of time and temperature (MR>LR>ER), but MR and LR cultivars showed the most significant changes (ER: $60.90{\pm}23.47%$, MR: $32.66{\pm}13.95%$, and LR: $32.53{\pm}5.87%$). On the basis of above results, MR cultivars were evaluated the highest quality, because high lipoxygenase activity, high fat acidity, and low germination rate have deteriorated in quality and generated off-odor. Thus, MR cultivars might be very important sources in food processing and stored dietary supplement aspects.

• 대기
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• 제16권2호
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• pp.67-83
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• 2006

The statistical analysis for the springtime windstorm in Korea shows that Yeongdong region has the highest occurrence frequency during recent 10 years. The objective of this study is to find possible mechanisms for the downslope windstorm formation in the Yeongdong region by using a mesoscale numerical model, WRF. Dynamical process, wave breaking (hereafter WB), is qualitatively investigated as the candidate mechanism for a windstorm event occurred in 5 April, 2005. WB is developed in upper troposphere downstream, since stable air is lifted by the Taebaek mountain. This process can cause and maintain the severe downslope windstorm by drawing the upper flow down to the surface. And the intensified downslope wind leads the hydraulic jump (hereafter HJ) in downstream region. Froude numbers at Chuncheon (upslope side), Seorak Mountain (crest), Yangyang (lee side), and the East Sea (distant downstream position) are estimated by about 0.4, 1.0, 1.6, and 0.6, respectively. This result implies that the accelerated and supercritical (Fr>1) flow adjusts to the ambient subcritical (Fr<1) conditions in the turbulent HJ. In addition, we find the formation of upstream inversion near top level of the mountain cause the intensification of HJ. Experiments to examine the orographic effect on the mechanisms suggest that the magnitudes of WB and HJ are larger in the experiment of higher topography, but there is no significant difference of windstorm magnitude among the experiments. Another important result from these sensitivity experiments is that the intensity of downslope windstorm strongly depends on the magnitude of upper (2~4 km) wind in upstream side.

• 한국지반공학회논문집
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• 제33권6호
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• pp.27-36
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• 2017

자갈다짐말뚝(Gravel Compaction Pile) 공법은 연약지반 개량공법 중의 하나로 육상 및 해상에서 연약 지반을 개량하기 위해 많이 사용되어 왔다. 자갈다짐말뚝으로 보강된 지반의 극한 지지력은 자갈다짐말뚝 및 지반의 강도, 치환율, 시공조건 등에 영향을 받으며 이를 예측하기 위한 다양한 예측식이 제안되었다. 하지만 기존 예측식을 활용한 극한지지력 예측은 오차율 및 변동성이 매우 크며, 실제 설계에 활용하기에는 부적합한 것으로 나타났다. 본 연구에서는 자갈다짐말뚝으로 보강된 지반의 극한 지지력을 예측하기 위하여 현장 재하시험결과를 활용한 다중회귀분석을 수행하였으며, 단일잔류 교차검증에 따른 예측오차평가를 통하여 가장 효율적인 입력변수를 선정하고 이에 대한 극한 지지력 예측식을 제안하였다. 또한 선정된 입력변수를 활용하여 인공신경망 적용에 따른 극한 지지력 예측오차를 평가하고 이를 기존 예측식에 따른 결과와 비교 분석하였다.