• Journal of Korea Water Resources Association
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• v.32 no.4
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• pp.457-467
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• 1999

No complete methods for estimating soil loss, included by rain storms, from a small watershed are available yet, and the best recommended method is to use measured data from the watershed. When no measured data is available from the watershed, empirical models for estimating the soil loss, such as the Universal Soil Loss Equation(USLE), is well recommended in practice. For using this equation, it is necessary to estimated the rainfall erosivity, commonly expressed as R, of the watershed. In this study, first we collected data of the probable rainfalls with the return periods of 2, 5, 10, 20, 30, 50, 80, 100, 200, and 500-yr and with the duration hours of 0.5, 1, 2, 3, 6, 12, and 24-hr. Using this data, we calculated the design values for R for the return period of 24-hr at each major rainfall-measuring station nationwide. Then we constructed the iso-erodent map of Korea for each return period of the 24-hr design storm. This study shows that the 24-hr duration iso-erodent map of the 5-yr return period is very similar to the annual average iso-erodent map of Korea. This study also shows that the 24-hr duration R-values of a certain return period can be estimated by multiplying certain parameters, obtained from this study, to the 24-hr duration R-values for the 5-yr return period or the annual average R-values. Finally, the R-values of the design storm with the 24-hr return period obtained from this study can be used for designing the settling basins at small watersheds.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.10a
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• pp.104-106
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• 2015

최근 인간의 개입을 최소화하면서 임무를 수행할 수 있는 무인항공기에 대한 활용도가 높아지는 가운데 무인선(Uamanned Maritime Vessel) 운용에 대한 관심도 높아지고 있다. 국내에서 무인선(Uamanned Maritime Vessel) 관련 프로젝트는 오염 방제 지원, 불법조업 감시, 조난자 수색 구조 등의 감시 및 구난 방제 지원 임무와 수로조사, 해양 기상 모니터링, 적조 감시 등 해양 조사 등을 목적으로 무인선(Uamanned Maritime Vessel)을 개발하는 중이다. 무인선은 관제센터(Maritime Control Station) 또는 모선을 통하여 원격 통제로 임무를 수행하게 되며, 이를 위하여 다양한 정보가 무선통신을 통하여 유인선-무인선, 무인선-무인선, 무인선-관제센터 간에 실시간으로 제공될 것으로 예상되어진다. 본 연구에서는 ITU-R Study Group Woking Party 5B를 분석한 후, 국내 개발 예정인 무인선(Uamanned Maritime Vessel) 운용을 위하여 요구되는 통신 서비스를 구분하여 정의 및 분류하고, 이를 바탕으로 데이터 전송속도, 트래픽 이용시간, 교통량을 바탕으로 필요한 주파수 산정을 위한 기초자료를 제공하는데 목적이 있다.

• The Journal of the Korea Contents Association
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• v.12 no.7
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• pp.255-260
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• 2012

This study aims to examine the generation of scatter rays by dividing it into the presence of the subject at the chest X-ray examination, the X-ray tube and detector in the X-ray room, the front of the patient window, the outside of the entrance door of the patient waiting room, opening of the entrance door, the outside of the radiological technologist's entrance door, and the opening of the radiological technologist's entrance door, etc. When there is a subject, as the subject is thicker, more scatter rays occur at each of the spots for measurement. And when the entrance door is closed at the measurement, fewer scatter rays are generated.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.426-427
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• 2008

전력의 안정적 공급, 공급 신뢰도 향상 및 도심지 인구밀집 지역의 전력공급 및 미화 등의 축면에서 송전분야에서의 지중화는 필수적이며 지속적으로 증가추세에 있다. 그러나 제한적인 지중공간을 활용함에 따른 여러 문제가 발생하고 있다. 지중선로 고장상황으로 1선 지락, 2선지락, 선간단락, 3상단락 등의 사고가 있으며 이러한 고장상황에서 발생하는 고장전류에 의한 열거동은 지중선로에 악영향을 준다. 그러므로 각 고장상황에 따른 지중선로의 영향에 대한 세부적인 검토가 필요하다. 본 논문에서는 각 고장상황에 따른 검토조건으로 1회선과 2회 선일 경우와 상배열이 정삼각배열, 수평/수직배열, 직각배열일 경우를 선정하여 지중선로에 미치는 영향을 EMTP, IDEARS, MARC를 활용하여 분석하였다.

• Journal of the Korean Society of Radiology
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• v.14 no.7
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• pp.907-913
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• 2020

There have been continuous controversies on medical X-ray protection and numerous researchers have been trying to prevent unnecessary exposure to radiation. As X-ray passes through the patient and obtains an image, it creates scattered ray due to interactions such as photoelectric effect and Compton scattering with the subject. As a result, both medical radiation staff and patient are exposed to unnecessary radiation on areas other than the target area. In response, this study will be assuming a body of a female, radiating X-ray on the phantom under the conditions of lumbar spine AP test, and measuring scattered ray around breasts and thyroid glands. Then, The experiment results were as follows. After application of non-shielding material, the average of scattered ray was 0.88 mR in thyroid measurement, 3.34 mR, Lt Axillary 3.54 mR, and Rt Axillary 3.03 mR in mamonary measurement but, After application of shielding material, the average of scattered ray was 0.16 mR in thyroid measurement, 0.60 mR, Lt Axillary 0.64 mR, and Rt Axillary 0.54 mR in mamonary measurement showing average scattered ray protection effect of about 82%. This study suggested the manufacturing method of a Jelly-type shielding material, identified the possibilities of researches on mixing various substances with radiology field, and verified the usability of the Jelly-type shielding material as a substitute for existing protection tools.

• Journal of radiological science and technology
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• v.33 no.3
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• pp.289-294
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• 2010

The purpose of this study is an evaluation of the performance of a detector under radiographic irradiation condition by fabricating the polycrystalline $HgI_2$ film detector. The polycrystalline $HgI_2$ film detectors with thickness of 210 and $320\;{\mu}m$ were fabricated by screen print technology. Measurements of X-ray sensitivity and dark current were performed for two detectors. And measurements of the linearity of X-ray response and reproducibility were performed for the detector of thickness $320\;{\mu}m$. For applied electric field strengths from 0.05 to $2\;V/{\mu}m$ to the detector of thickness $320\;{\mu}m$, the X-ray sensitivities were measured from 233 to $1,408{\times}106\;electrons/mR{\cdot}mm^2$. And the dark currents were measured from 3.2 to $118\;pA/mm^2$. Compared with values reported by Zhong Su et al., the X-ray sensitivities exhibit about two times larger than the X-ray sensitivities measured by Zhong Su et al. And the dark currents exhibit about nine times larger than the dark currents measured by Zhong Su et al. The linearity of X-ray response acquired 0.988 as a coefficient of correlation (r). Reproducibility acquired 0.002 as a coefficient of variation. This study provides the performance data of fabricated polycrystalline $HgI_2$ film detector available for an active matrix flat panel imager under radiographic irradiation condition.

• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.993-999
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• 1998

Aquatic raw materials easily undergo deteriorative changes, and thus it is very important to keep fish meats fresh during transport and processing. The $K_i$ value, biogenic amines, trimethylamine (TMA) and volatile basic nitrogen (VBN), which are reported fish freshness indices, were measured for 20 samples. The $K_i$ values were normally in the range of $7.8{\sim}43.6%$, except those for some fish including squid. The contents of biogenic amines were negligible, and a correlation (r=0.894) was found between the contents of TMA and VBN.

• Journal of Radiation Protection and Research
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• v.19 no.2
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• pp.121-132
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• 1994

This study concerns about the measurement and the investigation of environmental radiation characteristics which the components and the distribution of exposure rates by terrestrial y-rays in Taegu area. $4^{'}{\phi}{\times}4^{'}$ NaI(T1) scintillation detector with a multichannel analyzer was used in the measurement of y-rays as a part of in-situ spectrometry at twenty eight different locations in this area. The conversion into the exposure rate from the measured ${\gamma}-ray$ spectrum has been carried out leading to a net exposure rate and component ones by $^{40}K,\;^{238}U$ series and $^{232}Th$ series products which are known by the major parts in the terrestrial ${\gamma}-rays$ generally. As a result, the average exposure rate by the terrestrial ${\gamma}-rays$ in Taegu area is $9.4{\mu}R/h$ and the distribution of individual exposure rates shows more or less differences between these locations even after the consideration of diurnal and yearly variations which are always involved in these measurements. The component parts of exposure rates are distributed $^{40}K\;2.9{\sim}4.6{\mu}R/h,\;^{238}U$ series $1.2{\sim}3,\;1{\mu}R/h,\;^{232}Th$ series $2.5{\sim}5.0{\mu}R/h$ over the measured locations.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.31-33
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• 2008

전력계통에서 고장과 같은 어떤 원인에 의한 전계통 정전 또는 광역정전이 발생하였을 경우, 빠른 시간 내에 다시 전력을 공급하기 위한 조치를 취해야 한다. 그러나 계통의 구성 형태, 부하 조건, 발전기의 종류 등에 의해 계통 복구시 부하 투입에 의한 발전기 응동, 송전선로 가압시 선로 충전용량에 의한 과도현상 등 다양한 형태의 과도현상이 발생한다. 따라서 본 논문에서는 국내의 시송전 계통에서의 복구절차 수행시 송전선로를 가압할 때 발생하는 과도현상을 분석하였다. EMTP를 사용하여 시송전 계통을 모델링하였으며, 다양한 Sh.R 용량에 따른 과전압을 분석 하였다.

• Proceedings of the KSAR Conference
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• 2004.06a
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• pp.290-290
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• 2004

유전자재조합 소 소마토트로핀(recombinant bovine somatotropin, rBST)은 인슐린양성장인자(IGF)-1의 합성과 분비량 조절에 의해 당과 아미노산의 흡수 및 단백질합성의 촉진을 통한 체내흡수 영양소 이용효율 증가, 산유량 증진 및 증체 효과, 세포증식의 촉진작용 등이 있는 것으로 보고(Bauman, 1982; Mears, 1995; 권 등, 1997)된 바 있으며, 또한 최근에 젖소 및 육우빈우의 인공수정시 rBST를 투여하였을 때 1회 수정수태율, 혈중 progesterone 농도 및 IGF-1 농도 등에 영향을 미치는 것으로 보고하였다(Lucy 등, 1994; Bilby 등, 1999; Morales-Roura 등, 2001). (중략)