• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -2
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• pp.982-985
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• 2000

This paper presents channel estimation of an asynchronous W-CDMA reverse link using the interpolation and moving average algorithm in frequency-selective Rayleigh fading channel. The proposed algorithm is an interpolated decision-directed (IDD) block-wise moving average (BWMA) algorithm. The IDD-BWMA algorithm performs two- stage processes. The first stage performs data decision to make a virtual pilot channel by using linear interpolation channel estimation scheme. Then, the second stage performs the channel estimation of the “block-wise moving average” type by using a virtual pilot channel obtained in the first stage. By using Monte-Carlo computer simulations, we show that the proposed channel estimator is superior to other estimation schemes such as the WMSA(K=1) and DD-RAKE at higher Doppler frequencies, especially.

• Earthquakes and Structures
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• 제21권6호
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• pp.601-612
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• 2021

The paper concerns the selection of a design accelerograms used for the slope stability assessment under earthquake excitation. The aim is to experimentally verify the Arias Intensity as an indicator of the excitation threat to the slope stability. A simple dynamic system consisting of a rigid block on a rigid inclined plane subjected to horizontal excitation is adopted as a slope model. Strong ground motions recorded during earthquakes are reproduced on a shaking table. The permanent displacement of the block serves as a slope stability indicator. Original research stand allows us to analyse not only the relative displacement but also the acceleration time history of the block. The experiments demonstrate that the Arias Intensity of the accelerogram is a good indicator of excitation threat to the stability of the slope. The numerical analyses conducted using the experimentally verified extended Newmark's method indicate that both the Arias Intensity and the peak velocity of the excitation are good indicators of the impact of dynamic excitation on the dam's stability. The selection can be refined using complementary information, which is the dominant frequency and duration of the strong motion phase of the excitation, respectively.

• 한국지역지리학회지
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• 제15권2호
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• pp.204-214
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• 2009

본 연구의 목적은 2002년에 습지보호지역으로 지정된 천성산 화엄늪의 형성과정을 밝혀 지속가능한 습지관리를 위한 기초자료를 제공하는 것이다. 퇴적물 주상 시료와 부식의 탄소연대측정 결과로 볼 때, 화엄늪 습지보호지역의 초지는 지난 빙기의 기후변화와 관련없이 주민들의 화전농업에 의하여 만들어진 것으로 판단된다. 그리고 화엄늪은 천성산 정상부에 내린 강우가 지하로 침투하여 흐르다가 절리를 따라 능선 부분에서 용출하여 형성된 산지습지이다. 화엄늪 습지의 수량을 유지하기 위하여 습지보호지역 남서부의 주능선에 밀생하는 숲을 유지하여야 하며, 습지 하류 말단부를 지지하는 계단상의 거력제(block dam)가 붕락되지 않도록 유지하여야 한다. 그리고 습지의 주기적인 모니터링을 통하여 화엄늪 습지보호지역 내 지형과 수문변화를 측정하고 분석하여야 할 것이다.

• 한국지역지리학회지
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• 제10권1호
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• pp.206-214
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• 2004

본 연구의 목적은 정족산에 발달한 무제치 제2늪의 형성과정을 밝히는 것이다. 이를 위하여 꼭지와 곡지를 가로막은 암설지형의 형성과정을 분석하였다. 첫째, 무제치 제2늪이 발달한 곡지는 온난 습윤한 기후환경에서 절리를 따라 심층풍화 된 기반암의 풍화산물이 우세로 탈거되면서 만들어진 와지이다. 둘째, 무제치 제2늪은 플라이스토세의 최종빙기에 발달한 암괴류가 와지의 입구를 가로막음으로써 형성된 주변호소(marginal lake)가 사면에서 공급된 사력물질로 매립되면서 얕아져 수생식생이 자라게 되어 늪지로 변모하였다. 셋째, 제2늪은 늪지를 가로막은 암괴류 내의 세립 메트릭스 물질이 탈거됨으로써 점차 배수되어 육화되고 있다. 이를 지연시키기 위해서는 늪지를 가로막고 있는 암괴류 내의 빈 공간을 세립물질로 충진하여 배수를 억제하여야 한다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 춘계학술발표회논문집(1)
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• pp.571-576
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• 1996

Currently most nuclear power plants(NPPs) are adopted the mid-loop operation to minimize the overhaul period and save the operating cost. For mid-loop operation it is essential to install nozzle dam between RCS pipe and steam generator(SG). Because SG remains more highly contaminated with radioactive material than any other parts of the NPPs, the repairmen are very reluctant to carry out installing nozzle dam inside the SG. Until now, unfortunately, it appears that no practically applicable device was developed to provide the longstanding demand. Also the accidents have been reported by licenser event report during this operation mode due to loss of residual heat removal(RHR). The purpose of this paper is to conduct remotely blocking and disintegration of nozzle of a SG which has the highest radiation exposure during the maintenance in NPPs. The remote nozzle blocking device of a SG includes three bladders, hubs, air controller provisions to supply and contact air pressure into the bladders. This remote nozzle block device will give the larger operation margin to prevent the loss of RHR and minimize the radiation exposure dose to the repairman and shorten the overhaul periods.

• 지질공학
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• 제12권2호
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• pp.215-234
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• 2002

지하수댐은 대용량의 지하수를 효과적으로 확보할 수 있는 시설로서 저류수는 유역조건과 대수층조건, 상류부 오염원 분포와 수질에 따라 상수도용, 중수도용, 농업용 또는 공업용 등으로 다양하게 이용할 수 있으므로 적절한 지하수범 설치 방법은 용수부족을 해결할 수 있는 주요 기술의 하나이다. 지하수법을 활성화시키기 위해서는 대수층 위치 및 지층에 맞는 적절한 차수공법의 선택과 정밀한 물막이벽 시공, 대수층 구조·수문·물수지 등의 정확한 분석, 장기적인 지하수 이용계획과 저류역내 수질보전대책 수립, 수위·수질에 대한 장기 모니터링 실시로 지속적인 유지관리, 지속가능한 대용량 취수기술에 대한 조속한 연구, 지하수댐 개발로 인한 주변환경에 미치는 영향에 대한 철저한 분석 및 대책 수립 등이 필요하다. 그리고 해안지역 지하수법에서 발생하는 염수침입 현상을 방지하는 방안으로 물막이벽을 이중으로 설치하는 방법이 있다.

• Asian-Australasian Journal of Animal Sciences
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• 제13권6호
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• pp.774-780
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• 2000

For this study three types of block such as medicated urea-molasses-mineral block (MUMMB, 7% urea), urea-molasses-mineral blocks ($UMMB_a$ 7% urea) and urea-molasses-mineral blocks ($UMMB_b$ 21% urea) were prepared. Naturally infested 24 indigenous dairy cows with gastrointestinal nematodes were used to study the effect of MUMMB, $UMMB_a$ and $UMMB_b$ on different parameters (body weight, milk yield, serum urea level, milk urea level). The cows were offered normal diet added with 250 g block per cow for every day. Straw and green grasses were used as basal diet in the ration. The managemental facilities for all cows of each group were similar. Cows were stall fed, calves were tied up at night and had free access to their dam during day time. Milking was done once daily in the morning. The daily average live weight gains by MUMMB, $UMMB_a$, $UMMB_b$, and control group (no block) were 52.08 g, 44.44 g, 48.58 g, and 1.41 g respectively. The live weight gain were statistically significant (p<0.01) in comparison to control group. The highest daily milk yield was observed in MUMMB treated cows (2.39 L/d); followed by $UMMB_b$ treated cows (1.82 L/d) and $UMMB_a$ treated cows (2.16 L/d). The lowest milk yield was found in control group (1.54 L/d). This result differs significantly (p<0.05) between treated groups and also with control group. During urea-molasses-mineral blocks $UMMB_a$, $UMMB_b$ licking milk urea level increased from initial $22.76{\pm}2.35mg/dl$ to $35.46{\pm}4.80mg/dl$ and initial $22.86{\pm}2.96mg/dl$ to $40.66{\pm}0.87mg/dl$ respectively. This variation of milk urea level was statistically significant (p<0.001). Similarly during $UMMB_a$, and $UMMB_b$ blocks licking, serum urea level increased in both treated groups from initial $22.76{\pm}2.60mg/dl$ to $32.68{\pm}2.21$ and initial $23.70{\pm}2.78mg/dl$ to $40.48{\pm}3.24mg/dl$, respectively. This variation of serum urea level was also statistically significant (p<0.001). Use of MUMMB instead of UMMB was proved better for milk production and live weight gain in dairy cows under the village condition of Bangladesh where balanced ration for dairy cows are a major scarcity. And various concentration of urea in blocks positively affect milk and serum urea levels of indigenous dairy cows.

• 전자공학회논문지 IE
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• 제47권2호
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• pp.54-59
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• 2010

본 논문은 무선 데이터 네트워크에 적용 가능한 적응 프레임 길이 제어 방식을 가진 데이터 링크 프로토콜을 제안한다. 무선 데이터망은 수시로 변화는 에러 환경에 놓여 있다. 이런 에러 환경에서도 잘 적용할 수 있는 가변 프레임 제어 방식을 제안하고 그 성능을 분석하였다. 2상태 마코프 모델을 이용하여 채널 환경을 모델링하였다. 수치해석방식을 통하여 새롭게 제안한 방식이 다양한 종류의 에러환경에서도 좋은 성능을 발휘할 수 있음을 보여 주었다.

• Journal of information and communication convergence engineering
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• 제15권3호
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• pp.187-192
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• 2017

Autonomous driving vehicle research demands complex road and lane understanding such as lane departure warning, adaptive cruise control, lane keeping and centering, lane change and turn assist, and driving under complex road conditions. A fast and robust road lane detection subsystem is a basic but important building block for this type of research. In this paper, we propose a method that performs road lane detection from black box input. The proposed system applies Random Sample Consensus to find the best model of road lanes passing through divided regions of the input image under HSV color model. HSV color model is chosen since it explicitly separates chromaticity and luminosity and the narrower hue distribution greatly assists in later segmentation of the frames by limiting color saturation. The implemented method was successful in lane detection on real world on-board testing, exhibiting 86.21% accuracy with 4.3% standard deviation in real time.

• 한국농공학회논문집
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• 제52권1호
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• pp.33-40
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• 2010

The cemented sand and gravel (CSG) method is a construction technique that adds cement and water to rock-like materials, such as rivered gravel or excavation muck which that can be obtained easily at areas adjacent to dam sites. This study was performed to evaluate the planting properties of herbaceous plant and cool-season grass in CSG blocks that were manufactured by using CSG materials to develop environmentally friendly CSG method. The two types of CSG-0 without cement and CSG-100 with $100\;kg/m^3$ of cement were designed to evaluate compaction, unconfined compressive strength and growth of plants with cement content by using modified E compaction. To analyze growth properties of plants, germination ratio, visual cover, plant height and root length were measured in 4 weeks and 8 weeks after sowing. As the results, the germination regardless kinds of plants started within 5~7days and the germination ratio were in the range of 50~60 %. The visual cover of kinds of plants by visual rating system were in the range of 7~8 and the visual cover of tall fescue and perennial ryegrass was higher than that of lespedeza cuneata. The plant height and root length for tall fescue and perennial ryegrass in 8 weeks after sowing were in the range of 22~26 cm, 12~15 cm and 4~6 cm, 3~5 cm, respectively.