• 대한전기학회논문지:전력기술부문A
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• 제55권12호
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• pp.570-575
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• 2006

This paper develops methodology in order to consider CHP(Combined Heat and Power) capacity in the Basic Plan of Long Term Electricity Supply & Demand. We develop generating cost of CHP considering electric and heat. Also we develop mixed load duration curve which includes the electric load and heat load and then apply CHP capacity to SCM(Screening Curve Method) considering CHP feature. Accordingly, it decide the optimal CHP capacity in the Basic Plan of Long Term Electricity Supply & Demand. Also, We perform the sensitivity analysis according to cost variation.

• 대기
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• 제29권1호
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• pp.13-20
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• 2019

Since 1985, the Dobson Spectrophotometer has been operated at Yonsei University, and this instrument has monitored the daily representative total ozone in Seoul. Climatological value for total ozone in Seoul is updated by using the daily representative observation data from 1985 to 2017. After updating the daily representative total ozone data, seasonal and inter-annual variation of total ozone in Seoul is also estimated after calculating inter-comparison between ground (Dobson Spectrophotometer) and satellite [Total Ozone Mapping Spectrometer (TOMS) and Ozone Monitoring Instrument (OMI)] observations. The global average of total ozone measured by satellite is 297 DU, and its recent amount is about 3.5% lower than the global amount in 1980s. In Seoul, daily representative total ozone is ranged from 225 DU to 518 DU with longterm mean value of 324.3 DU. In addition, monthly mean total ozone is estimated from 290 DU (October) to 362 DU (March), and yearly average of total ozone have been continuously increased since 1985. For the long-term trend of total ozone in Seoul, this study is considered the seasonal variation, Solar Cycle, and Quasi-Biennial Oscillation. In addition to the natural oscillation effect, this study also considered to the long-term variation of sudden increase of total ozone due to the secondary ozone peak. By considering these natural effects, the long-term total ozone trends from 1985 to 2017 are estimated to be 1.11~1.46%/decade.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.214-215
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• 2007

Int this paper, we studied the analysis on long-term durability and output power characteristics of PV modules by variation on local thermal property. Using 5 modules(80W), we measured the maximum output power change during the test period. And the optical transmittance of glass was compared with PV module's maximum power fluctuation. The external environment change effected contamination on the entire or local surface of module. This caused the local temperature variation of each solar cell on PV module. The specific analysis is shown in the following paper.

• 보건행정학회지
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• 제27권1호
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• pp.56-62
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• 2017

Background: There have been deviations in the regional rate of certification in Korean long-term care insurance (LTCI). This study aimed to explore the determinants of the rate of certification in LTCI. Methods: The panel data of the year 2010-2014 of the 227 National Health Insurance Service (NHIS) regional office were used. Making use of 26 explanatory variables (socio-demographic factors, access to the long-term care services, etc.), we estimated the random effects model using STATA SE ver. 13.0 program (Stata Corp., College Station, TX, USA) and tried to find out the determinants of the regional rate of certification. Results: Estimation results showed that the most important determinants of the regional rate of certification in LTCI are the long-term care infrastructure such as capacity or number of the homecare service institution, sanatorium, or convalescent hospital. The number of the elderly who lives alone and the dimentia patients were positively related to the regional rate of certification in LTCI. Conclusion: The estimation results implied that the regional variation in the rate of certification in LTCI has nothing to do with the NHIS regional offices or their employees. To alleviate the deviation in the regional rate of certification in LTCI, we suggested the analysis of the deviation in the survey checklist. We also proposed to found the regional comprehensive support center to prevent the geriatric illness and to improve the residents' health, etc.

• 한국지반환경공학회 논문집
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• 제14권9호
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• pp.13-19
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• 2013

천곡동굴은 동해시에 자리잡고 있는 석회암동굴로서 많은 돌리네를 가지고 있어 관광적 가치와 교육적 가치가 매우 높다. 하지만 천곡동굴은 시가지에 위치하고 있어 접근이 용이한 반면 하수의 유입 등에 의해 환경적 영향을 받을 가능성이 매우 크다. 본 연구에서는 천곡동굴의 수질환경을 장기 모니터링하여 생태계의 영향을 조사하고, 향후 장기 모니터링을 위한 인자를 선정하였다. 그 결과 천곡동굴 내 지하수의 수온은 $14^{\circ}C$, 용존 산소량은 10mg/L 이상, pH는 7-8의 범위에서 안정되게 유지되고 있어, 수생태계에 부정적 영향을 주는 수질적 요소는 없는 것으로 판단되었다. 관람객의 안전을 확보하기 위한 강우기준으로서 일강우로서 60mm/d가 적절하며 향후 장기 모니터링을 위해서 전기전도도를 주된 인자로 이용하고 pH와 탁도를 보조적으로 활용하는 것이 적절하며, 계절적 변화 등을 ORP를 이용하여 모니터링하는 것이 적절하다고 판단되었다.

• Journal of Astronomy and Space Sciences
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• 제28권1호
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• pp.9-12
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• 2011

Results of an analysis of 11 nights of R-filter CCD photometry data of an intermediate polar MU Camelopardalis (MU Cam) obtained at the Korean 1.0 m telescope at Mt. Lemmon are reported. After checking the spin period with our data, $P_{spin}=0.^d01373801(59)$, we compiled the reported data of maxima timing and an O-C diagram analysis has been carried out to understand the spin period variation. A significant spin period variation was detected, and fitting the O-C points to a cubic parabola led to an ephemeris of $BJD_{max}=2453682.4178(94)+0.0137380(13)E-2.07(55){\times}10^{-11}E^2+2.28(52){\times}10^{-15}E^3$. The torque experienced by the magnetic compact star accreting in a disk is estimated as ${\tau}{\approx}1.815{\times}10^{35}gcm^2/s^2$ in a simple approximation in order to show how important monitoring the period variation is. Thus we conclude that monitoring the long-term spin period variation will help to understand the physical condition of magnetic compact stars.

• Fisheries and Aquatic Sciences
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• 제10권4호
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• pp.215-219
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• 2007

Long-tenn variation in krill (Euphausia superba) and salp (mainly Salpa thompsoni) stocks was compared to environmental changes in the Atlantic and Indian sectors of the Antarctic. Environmental conditions examined were air temperature, water temperature, salinity, and sea-ice extent from 1926 to 1938 and from 1982 to 2000. The long-term pattern of krill was opposite to that of salp: krill stock decreased while salp stock increased concurrently. Krill stock was about three-fold higher from 1926 to 1938 than from 1982 to 2000, but salp was about four -fold lower in 1926-1938 than in 1982-2000. A wanning trend was observed in the environmental data, and the long-term variation in krill and salp stocks was affected by this trend.

• 대한두경부종양학회:학술대회논문집
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• 대한두경부종양학회 2004년도 제21차 학술대회
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• pp.208-208
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• 2004

• 천문학회보
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• 제10권
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• pp.5.2-5.2
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• 1985

• 한국대기환경학회지
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• 제32권1호
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• pp.114-126
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• 2016

Many cohort studies have reported associations of individual-level long-term exposures to $PM_{10}$ and health outcomes. Individual exposures were often estimated by using exposure prediction models relying on $PM_{10}$ data measured at national regulatory monitoring sites. This study explored spatial and temporal characteristics of regulatory $PM_{10}$ measurement data in South Korea and suggested $PM_{10}$ concentration metrics as long-term exposures for assessing health effects in cohort studies. We obtained hourly $PM_{10}$ data from the National Institute of Environmental Research for 2001~2012 in South Korea. We investigated spatial distribution of monitoring sites using the density and proximity in each of the 16 metropolitan cities and provinces. The temporal characteristics of $PM_{10}$ measurement data were examined by annual/seasonal/diurnal patterns across urban background monitoring sites after excluding Asian dust days. For spatial characteristics of $PM_{10}$ measurement data, we computed coefficient of variation (CV) and coefficient of divergence (COD). Based on temporal and spatial investigation, we suggested preferred long-term metrics for cohort studies. In 2010, 294 urban background monitoring sites were located in South Korea with a site over an area of $415.0km^2$ and distant from another site by 31.0 km on average. Annual average $PM_{10}$ concentrations decreased by 19.8% from 2001 to 2012, and seasonal $PM_{10}$ patterns were consistent over study years with higher concentrations in spring and winter. Spatial variability was relatively small with 6~19% of CV and 21~46% of COD across 16 metropolitan cities and provinces in 2010. To maximize spatial coverage and reflect temporal and spatial distributions, our suggestion for $PM_{10}$ metrics representing long-term exposures was the average for one or multiple years after 2009. This study provides the knowledge of all available $PM_{10}$ data measured at national regulatory monitoring sites in South Korea and the insight of the plausible longterm exposure metric for cohort studies.