• Journal of Animal Science and Technology
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• 제56권1호
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• pp.2.1-2.8
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• 2014

Hanwoo (Korean cattle) is the native, taurine type of cattle breed of Korea and its history as a draft animal dates back to 5000 Years. In earlier times Hanwoo was used extensively for farming, transportation. Over the period of time, Hanwoo has changed to be meat type cattle. Full-scale production of Hanwoo as meat-type cattle has occurred since 1960s with the rapid growth of the Korean economy. Hanwoo is one of the most economically important species in Korea as it is a significant source of nutrition to the Korean people. Hanwoo beef is the most cherished food of Korea. One of the main goals of researchers is to increase the meat quality, quantity and taste of the beef. In this review we describe the origin, domestication of Hanwoo cattle and breeding program initiated from 1980's. Moreover the advent of technological advancement had provided us a platform to perform genome wide selection on economic traits and its implementation into traditional breeding programs.

• 한국물환경학회지
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• 제22권1호
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• pp.110-115
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• 2006

Flooding situation of Sutak basin was simulated and simulation seemed to be consistent with the real flooding situation in terms of high water levels and timings of flooding. The flood simulation model was used to evaluate alternatives to mitigate flooding problems in Sutak basin. From the evaluation of flood mitigation plans, it was found that combined operation of Sutak and Inchang pumping stations through partial diversion of inflow of Sutak pumping station to Inchang pumping station was the most effective one among the suggested mitigation plans. About 500 meter diversion channel will be needed to send 30% of Sutak pumping station inflow to Inchang pumping station. This will reduce overload of Sutak pumping station and the storage capacity of Inchang pumping station will be more efficiently utilized.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2004년도 한국우주과학회보 제13권2호
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• pp.251-253
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• 2004

Automated east/west and north/south station-keeping maneuvers were simulated for the geostationary COMS (Communication, Ocean and Meteorological Satellite) satellite that will be launched around year 2008, The satellite has to be maintained within ${\pm}0.05^{\circ}$ at the nominal longitude of $128.2^{\circ}\;E$. The general perturbation method was used to keep the position of the geostationary satellite. Weekly based east/west and biweekly based north/south station-keeping maneuvers were investigated. The sun pointing perigee control method and two-bum strategy were used for the east/west station-keeping maneuver. Switching the right ascension of the ascending node to descending node was adopted for the north/south station-keeping maneuver. One year station-keeping maneuver was demonstrated and various station-keeping orbital parameters were analyzed.

• Journal of Astronomy and Space Sciences
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• 제38권1호
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• pp.65-82
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• 2021

For the vast majority of geostationary satellites currently in orbit, station keeping activities including orbit determination and maneuver planning and execution are ground-directed and dependent on the availability of ground-based satellite control personnel and facilities. However, a requirement linked to satellite autonomy and survivability in cases of interrupted ground support is often one of the stipulated provisions on the satellite platform design. It is especially important for a geostationary military-purposed satellite to remain within its designated orbital window, in order to provide reliable uninterrupted telecommunications services, in the absence of ground-based resources due to warfare or other disasters. In this paper we investigate factors affecting the robustness of a geostationary satellite's orbit in terms of the maximum duration the satellite's station keeping window can be maintained without ground intervention. By comparing simulations of orbit evolution, given different initial conditions and operations strategies, a variation of parameters study has been performed and we have analyzed which factors the duration is most sensitive to. This also provides valuable insights into which factors may be worth controlling by a military or civilian geostationary satellite operator. Our simulations show that the most beneficial factor for maximizing the time a satellite will remain in the station keeping window is the operational practice of pre-emptively loading East-West station keeping maneuvers for automatic execution on board the satellite should ground control capability be lost. The second most beneficial factor is using short station keeping maneuver cycle durations.

• 대한토목학회논문집
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• 제29권1D호
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• pp.121-128
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• 2009

세종과학기지(KingSejong Station)가 위치한 킹조지섬(King George Island)은 지역 특성상 남극대륙으로 향하는 관문이면서 전초기지와 같은 역할을 하는 지역으로 한국의 남극 활동 영역 확장에 지대한 영향을 끼치고 있다. 그러나 현재 세종과 학기지 주변의 지리정보는 정밀측량이 이루어 지지 못하여 우리나라 활동영역에 대한 정확한 지리적 위치정보를 확보하지 못한 상태이며, 또한 지리정보구축의 가장 기본적이면서 세종과학기지의 국제 활동에 대한 묵시적 표현수단이라 할 수 있는 지도를 외국에 의존하여 사용하고 있는 실정이다. 따라서 본 연구에서는 경량 항공사진측량을 적용하여 지리정보구축에 필요한 수치지형도를 제작하고 기존의 수치지형도와 비교하여 빙하 후퇴와 변화 분석을 실시함으로써 향후 남극 환경과 관련한 연구에 실용적인 기초자료로 제공하고자 한다.

• 한국대기환경학회지
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• 제13권6호
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• pp.415-426
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• 1997

Some arguments have been about over the representativeness of government-run air quality monitoring stations among scholars and non-governmental organizations (NGOs). However, it is not a simple problem to move monitoring stations because of continuity of data and high cost. So it is necessary to complement the monitoring data if it do not represent the ambient air quality properly. The purpose of this study was to evaluate the representativeness of some monitoring stations using passive $NO_2$ samplers and to find a complementary method from linear regression. Two stations were chosen for the evaluation: Shinlim Station was one of the most controversial stations in Seoul and Banpo Station had the best reputation. Air qualities were surveyed at seven points around each monitoring station with consideration of land use and distance. The ratios of the average $NO_2$ levels of the areas to these at the monitoring stations were 1.59 for Shinlim Station and 1.03 for Banpo Station. The differences between the average $NO_2$ levels and those at the monitoring stations were 10.75 ppb for Shilim Station and 0.34 ppb for Banpo Station. The correlation coefficients between the two levels were 0.7668 for Shinlim and 0.7662 for Banpo. The average coefficients of determination $(R^2)$ were 0.61 for Shinlim and 0.61 for Banpo. The Shinlim Station could not represent the air quality of Shinlim-Dong good because it is located in a green area at an outskirt of Shinlim-Dong. But the Banpo Station located in a central residential area of Banpo-Dong showed a fair representativeness. However, air quality turned out to be different with land use such as residential area, green area or road: the air quality data from a monitoring station located at a certain land use should not be interpreted as representing the air quality at any sites around the station. Equations to predict the average $NO_2$ levels of each area from the data from the monitoring stations were presented based on linear regression.

• 한국환경과학회지
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• 제12권2호
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• pp.207-215
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• 2003

The purpose of this study is to estimate the air quality of subway stations having underground platforms in Busan Metropolitan City, from September to November 2000, over seven times. The places of the investigation include Yonsan-dong station, Somyon station, Busan station, Nampo-dong station, and Dusil station. Samplings were conducted at three points in each station, i.e. gates, ticket gates, and platforms. CO, NO, $NO_2$, and $O_3$ were the main components of air for this analysis. In order to more fully understand station environments, we also measured an air temperature at each point. The results showed that the $O_3$ average concentration of Yonsan-dong station was higher than others with 38~51 ppb. The average concentration of NO was high at the ticket gate and platform at Somyon station (119 ppb, 122 ppb) and Nampo-dong station (102 ppb, 100 ppb). These results show that the air pollution of stations with underground shopping malls were higher than others. At Somyon station having a junction station, NO and $NO_2$ concentration levels of platform-2 (noncrowded) were higher than platform-1 (crowded). This is most likely due to the accumulation of air pollutants and inadequate ventilation systems. To find the relationship of the indoor (platform) and outdoor (gate), we analyzed the I/O ratio. The averages of CO and $O_3$ were both higher than one: 1.16 and 1.82, respectively. In the correlations between each material and the others, NO vs $NO_2$ was the highest with R=0.63. In the correlations between indoor and outdoor, $O_3$ was the highest with R=0.64.

• 한국산학기술학회논문지
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• 제13권2호
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• pp.893-899
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• 2012

본 논문은 경인선 백운역 및 백운역세권을 대상으로 철도에 의해 양분된 지역생활권의 단절 해소 및 철도시설 연변부지의 효율적 토지이용을 통한 입체적인 철도 환승시스템을 제안함과 동시에 철도 이용객의 편의를 도모하며 기존의 단절된 녹지축을 활성화하여 친환경적이며 안전하고, 편리한 주거환경의 개선을 통해 지역주민들의 삶을 한층 풍요롭게 하고 나아가 지역 생활권의 활성화 방안을 모색하는 것에 있다.

• 산업공학
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• 제11권3호
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• pp.55-63
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• 1998

In this study we consider a CONWIP system in which the processing times at each station follow an exponential distribution and the demands for the finished products arrive according to a compound Poisson process. The demands that are not satisfied instantaneously are assumed to be lost. We assume that the lot size at each station is greater than one. For this system we develop an approximation method to obtain the performance measures such as steady state probabilities of the number of parts at each station, average number of parts at each station and the proportion of lost demands. For the analysis of the proposed CONWIP system, we model the CONWIP system as a closed queueing network with a synchronization station and analyze the closed queueing network using a product form approximation method. A recursive technique is used to solve the subnetwork in the application of the product-form approximation method. To test the accuracy of the approximation method, the results obtained from the approximation method were compared with those obtained by simulation. Comparisons with simulation have shown that the accuracy of the approximate method is acceptable.

• 대한원격탐사학회지
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• 제24권5호
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• pp.409-416
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• 2008

Recently, KARI developed "KOMPSAT-2 Terminal for Polar Station" which is high performance system newly required for stimulating KOMPSAT-2 application. The KOMPSAT-2 Terminal for Polar Station consists of one receiving system and two processing systems. The receiving system has been installed at Svalbard Satellite Station located at Norwegian Svalbard island. and the two receiving systems have been installed at Kongsberg Satellite Service AS located at Tromso Norway and Spot Image SA located at Toulouse France respectively. In this paper overall items of KOMPSAT-2 Terminal for Polar Station, which includes requirements, designs and operation concepts, are to be addressed with the verification result on its performance.