• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.481-481
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• 2016

하천퇴적물은 물의 순환과정에서 유역으로부터 유입되는 물질에 따라 조성이 변하게 된다. 특히 입자가 작은 토양과 유기성 물질들은 물순환과정에 이동성이 크게 나타나며, 인간에 의해 개발된 지역은 자연상태에 비해 이동하는 물질이 많이 나타나곤 한다. 본 연구에서는 하천에 건설된 보에 대한 퇴적물 조사를 실시함으로서 향후 수질관리에 필요한 기초 자료를 수집하고자 하였다. 본고에서는 금강과 낙동강에 건설된 보의 주요지점에 대한 퇴적물 조사를 실시하고 수질영향을 평가하였다. 조사는 홍수기전과 홍수기후로 구분하여 2회에 걸쳐 실시하였으며 물리적 성상과 화학적 항목에 대한 분석을 실시하였다. 입도분석 결과 금강 주요 10개 지점의 퇴적물 조성은 Sand, Silt와 Clay 성분이 혼합되어 있는 것으로 분석되었으며, 삼각좌표 분류법에 의한 토성은 대부분의 지점이 실트질양토(SiL)로 평가되었다. 완전연소가능량은 0.35~1.37로 전 지점에서 하천 호소 퇴적물 오염평가 기준의 유기물 함량기준 13%보다 높지 않은 것으로 나타났으며 홍수기 전 후에도 거의 유사하였다. 금강에서는 중금속뿐만 아니라 유기물 및 영양염류도 기준보다 낮게 나타났으며, 모든 항목에서 환경부예규인 하천 호소퇴적물 오염평가 기준보다 낮게 평가되었다. 하상 퇴적물이 수질에 미치는 영향을 평가하는 용출실험에서도 유기물 및 중금속 모두 수질에 미치는 영향은 거의 없는 것으로 평가되었다. 낙동강 주요 26지점의 입도분석 결과 퇴적물 조성은 대부분 Sand로 구성되어 삼각좌표 분류법에 의한 토성은 사토(S)로 평가되었다. 홍수기 전 후에 조사한 결과 완전연소가능량은 0.27~2.85으로 전 지점에서 하천 호소 퇴적물 오염평가 기준의 유기물 함량 기준보다 낮았으며 홍수기 전 후에도 거의 유사하였다. 화학적 성상 분석 결과 모든 항목에서 환경부예규인 하천 호소퇴적물 오염평가 기준보다 낮게 평가되었으며, 용출실험에서도 유기물 및 중금속 모두 수질에 영향을 거의 미치지 않는 것으로 평가되었다. 이번 조사는 4대강 건설 후 하상이 안정화 되지 않은 상태로 인해 지점간 특별한 경향성은 확인할 수 없었으며 보다 정확한 결과 도출을 위해서는 장기적인 조사를 통해 평가해야 할 것으로 판단되었다.

• Journal of agricultural medicine and community health
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• v.35 no.3
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• pp.301-313
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• 2010

Objectives: The purpose of this research is to provide foundational data for reeducation concerning prehospital emergency care in order to improve the performance of emergency medical technicians (EMTs) working at 119 fire safety centers. Methods: Data were collected using a mail-in questionnaire developed by researchers from 288 subjects, who were EMTs working at 119 fire safety centers and local units in the Gwangju Metropolitan City and South Jeolla Province, from March 1, 2009 to April 31, 2009. Results: The mean score for EMTs' knowledge on drug intoxication was7.04 out of a total of 10 points. The mean score for EMT's attitude of emergency treatment performance on drug intoxication was 2.96 out of a total of 4 points. The level of EMT's knowledge is relatively high regarding prehospital care for drug intoxication. The EMT's attitude of performances demonstrated an understanding of the patients' conditions. However EMTs did not actively explain the prognosis and medical conditions for their patients. Conclusions: This research will contribute to making plans for reeducating emergency crew working at 119 fire centers so that can they have a more active attitude towards prehospital emergency medical care.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.493-505
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• 2017

This study examined the relationships between health behavior, premenstrual coping, premenstrual syndrome symptoms, and subjective happiness of female college students. The data were collected through self-report questionnaires between March 7 and April 20, 2016. Participants were comprised of a convenience sample of 122 female college students. Stepwise multiple regression analysis revealed subjective health status (${\beta}=.23$, p<.011), premenstrual syndrome symptoms (${\beta}=-.22$, p<.012), and average length of menstrual period (${\beta}=-.17$, p<.044) to be significant predictors of subjective happiness in female college students. These variables accounted for 14.0% of subjective happiness scores. It is meaningful that premenstrual syndrome symptoms and average length of menstrual period affected the subjective happiness in female college students. Therefore, to facilitate subjective happiness in female college students, efficient management and intervention regarding premenstrual syndrome symptoms and general health are required.

• The Journal of Korean Society for Radiation Therapy
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• v.27 no.2
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• pp.167-174
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• 2015

Purpose : The pre-treatment QA using Portal dosimetry for Volumetric Arc Therapy To analyze whether maintaining the reproducibility depending on various factors. Materials and Methods : Test was used for TrueBeam STx$^{TM}$ (Ver.1.5, Varian, USA). Varian Eclipse Treatment planning system(TPS) was used for planning with total of seven patients include head and neck cancer, lung cancer, prostate cancer, and cervical cancer was established for a Portal dosimetry QA plan. In order to measure these plans, Portal Dosimetry application (Ver.10) (Varian) and Portal Vision aS1000 Imager was used. Each Points of QA was determined by dividing, before and after morning treatment, and the after afternoon treatment ended (after 4 hours). Calibration of EPID(Dark field correction, Flood field correction, Dose normalization) was implemented before Every QA measure points. MLC initialize was implemented after each QA points and QA was retried. Also before QA measurements, Beam Ouput at the each of QA points was measured using the Water Phantom and Ionization chamber(IBA dosimetry, Germany). Results : The mean values of the Gamma pass rate(GPR, 3%, 3mm) for every patients between morning, afternoon and evening was 97.3%, 96.1%, 95.4% and the patient's showing maximum difference was 95.7%, 94.2% 93.7%. The mean value of GPR before and after EPID calibration were 95.94%, 96.01%. The mean value of Beam Output were 100.45%, 100.46%, 100.59% at each QA points. The mean value of GPR before and after MLC initialization were 95.83%, 96.40%. Conclusion : Maintain the reproducibility of the Portal Dosimetry as a VMAT QA tool required management of the various factors that can affect the dosimetry.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.10
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• pp.855-864
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• 2009

The effect of toxicant on the inhibition of nitrification was investigated, using concentrated nitrifying bacteria of both attached and suspended growth. This nitrifying organism was originally obtained from the activated sludge of sewage treatment plant and cultivated for more than three months. The object of this experiment is to determine the effect of the specific surface area and the growth condition of nitrifying bacteria on toxicity of heavy metal. The results of this study were as follows. The specific surface area of both attached and suspended growth of nitrifying organism was proven to be a major factors in determining the inhibition of nitrification of heavy metal such as $Cu^{++}$ion. When the condition of attachment and detachment was compared in an experiment using attached growth nitrifier, the effect on toxicant was 1.12 times less in attached condition than in detached condition for Nitrosomonas, and 1.09 times less for Nitrobacter. In case of suspended growth nitrifier, the effect on toxicant was 1.46 times less in non-ground condition than in ground condition for Nitrosomonas, and 1.35 times less for Nitrobacter. Also, similar results were obtained in a set of experiments, without adding nitrite to the substrate. In an experiment that compared attached condition using attached growth nitrifier with detached condition using attached growth nitrifier, the effect on toxicant was 1.83 times less in attached condition than in detached one for Nitrosomonas, and 1.78 times less for Nitrobacter. In case of suspended growth nitrifier, the effect on toxicant was 1.27 times less in non-ground condition than in ground condition for Nitrosomonas, and 1.32 times less for Nitrobacter.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.10
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• pp.4805-4811
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• 2013

The purpose of this study is to analyse the satisfaction level and psychological status of senior students of "Silver College," or seniors' college. For the analysis, questionnaire survey was conducted to senior students of Silver Colleges of B and K University in Busan from May 1 through 31, 2013. The analysis methods used are SPSS Win 18.0 program on analysis of frequency, one-way analysis of variance, a correlation analysis, simple regression analysis and multiple regression analysis, with analysis of actual proof for 5% significance level. The result of analysis indicates that the senior students' satisfaction level rose and serious physical symptoms improved after taking silver college programs from before. This study is significant in that it provides theoretical grounds for increasing the number of silver colleges with professional and socially-renowned professors as faculty, and developing further programs and policies for the solution of aggravating physical and mental problems more and more senior people are faced with in this fast aging society.

• Convergence Security Journal
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• v.20 no.2
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• pp.145-153
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• 2020

The aviation safety policy master plan is promoting the development of aviation safety management technology applying the 4th industrial revolution technology with the goal of establishing a flawless aviation safety management system and establishing a future aviation safety infrastructure. The master plan includes the establishment of various aviation safety management systems such as aircraft fault management using AI & Big data and flight training system using VR/AR. Currently, the Air Force is promoting a flight safety management system using new technology under the goal of building smart air force. Therefore, this study intends to apply the 4th Industrial Revolution technology to the aircraft condition check system that finally checks the safety of the aircraft before flight. The Air Force conducts airframe flaw checks and pre-flight aircraft check. In this study, we architect the airframe flaw check system using AI and drones, and the pre-flight aircraft condition check system using the IoT and big data for more precise and detailed check of aircraft condition and flawlessness check.

• Journal of Environmental Impact Assessment
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• v.21 no.4
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• pp.553-565
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• 2012

영산강 하구에서 담수유입에 따른 저염수의 거동을 파악하기 위하여 EFDC 모델을 수행하였다. 모델의 수행은 홍수기 배수갑문 확장 전 후로 나누어 수행하였으며, 모델의 마지막 담수유입시점으로부터 16일 후 해역이 준 정상상태에 도달하기까지 저염수의 확산양상을 시간 경과순으로 살펴보았다. 그 결과, 담수유입이 멈춘 후에 저염수는 방류시점으로부터 약 6시간 경과 후에 배수갑문 전면 해역으로부터 해측으로 최대의 확산을 보였으며, 약 2~7일 후 염분의 분포 양상은 담수가 유입되기 전으로 회복되는 경향을 보였다. 한편, 배수갑문을 확장하기 전보다 배수갑문을 확장한 후에 담수유입 후 해역이 준 정상상태에 도달하는 시간이 더욱 짧았는데, 이는 시간당 방류량의 증가가 난류혼합을 강하게 하고, 해측으로 더 멀리 확산된 저염수는 외해수에 의해 보다 쉽게 혼합되기 때문인 것으로 판단된다. 따라서, 본 해역에서 일정한 양의 담수가 유입되는 경우, 저염수의 확산은 시간당 방류량이 크고 방류지속시간이 짧을수록 해역이 준정상상태에 도달하는 시간이 더욱 짧아질 것으로 사료된다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.12
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• pp.841-847
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• 2019

Time series data of 6-component loads were computed for a horizontal axis wind turbine rotor in yawed operating conditions with both rotating and non-rotating coordinate systems fixed at a center of a rotor hub. In this study, a well-known 20 kW class of the NREL Phase VI rotor was used for a model wind turbine, and this paper focuses on the yaw moments and over-turning moments for the operating wind speed range between 6 to 25 m/s. Unsteady blade element momentum theorem was adopted to get the aerodynamic loads acting on the wind turbine rotor. Computed 6-component loads using the developed UBEM code were compared with those using the NREL FAST program. From the computed results, both yaw and over-turning moments would be basic inputs to determine not only the specification of yawing mechanism but also the design condition of foundation.

• Journal of the Society of Naval Architects of Korea
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• v.38 no.4
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• pp.30-38
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• 2001

The current is considered in the conventional manoeuvering equation. This equation is represented as the nonlinear state and measurement equations in which external forces and the direction and the velocity of current are augmented as that variables. The external forces are modeled as the third-order Gauss-Markov processes and the direction and the velocity of current are assumed to be constant. The augmented state variables are estimated with extended Kalman-Bucy filter and the fixed-interval smoother. While Hwang estimated motion state variables, hydrodynamic coefficients and the current variables simultaneously by using extended Kalman filter, external forces of surge, sway and yaw and the direction and the velocity of current are the only parameters to be estimated in the estimation-before-modeling method. The current variables are satisfactorily estimated in simulation process where the measurement noise is present.