• 대기
• /
• 제15권2호
• /
• pp.101-118
• /
• 2005

Atmospheric ozone changes temporally and spatially according to both anthropogenic and natural causes. It is essential to quantify the natural contributions to total ozone variations for the estimation of trend caused by anthropogenic processes. The aims of this study are to understand the intrinsic natural variability of long-term total ozone changes and to estimate more reliable ozone trend caused by anthropogenic ozone-depleting materials. For doing that, long-term time series for Seoul of monthly total ozone which were measured from both ground-based Dobson Spectrophotometer (Beck #124)(1985-2004) and satellite TOMS (1979-1984) are analyzed for selected period, after dividing the whole period (1979~2004) into two periods; the former period (1979~1991) and the latter period (1992~2004). In this study, ozone trends for the time series are calculated using multiple regression models with explanatory natural oscillations for the Arctic Oscillation(AO), North Atlantic Oscillation(NAO), North Pacific Oscillation(NPO), Pacific Decadal Oscillation(PDO), Quasi Biennial Oscillation(QBO), Southern Oscillation(SO), and Solar Cycle(SC) including tropopause pressure(TROPP). Using the developed models, more reliable anthropogenic ozone trend is estimated than previous studies that considered only QBO and SC as natural oscillations (eg; WMO, 1999). The quasi-anthropogenic ozone trend in Seoul is estimated to -0.12 %/decade during the whole period, -2.39 %/decade during the former period, and +0.10 %/decade during the latter period, respectively. Consequently, the net forcing mechanism of the natural oscillations on the ozone variability might be noticeably different in two time intervals with positive forcing for the former period (1979-1991) and negative forcing for the latter period (1992-2004). These results are also found to be consistent with those analyzed from the data observed at ground stations (Sapporo, Tateno) of Japan. In addition, the recent trend analyses for Seoul show positive change-in-trend estimates of +0.75 %/decade since 1997 relative to negative trend of -1.49 %/decade existing prior to 1997, showing -0.74 %/decade for the recent 8-year period since 1997. Also, additional supporting evidence for a slowdown in ozone depletion in the upper stratosphere has been obtained by Newchurch et al.(2003).

• Fisheries and Aquatic Sciences
• /
• 제2권2호
• /
• pp.199-209
• /
• 1999

Before investigating the long-term variations in macrobenthic communities sampled in the Chokchon macrotidal flat in Inchon, Korea, from 1989 to 1996, we need to understand how environmental factors in the area vary. As potential governing agents of tidal flat communities, abiotic factors such as mean sea level, seawater, air temperature, and precipitation were considered. Data for these factors were collected at equal intervals from 1976 or 1980 to 1996, and were analyzed using a decomposition method. In this analysis, all the above variables showed strong seasonal nature, and yielded a significant trend and cyclical variation. Positive trends were seen in the seawater and air temperatures, and based upon this relationship, it was found that the biological sampling period of our program has been carried out during warmer periods in succession. This paper puts forth some hypotheses concerning the response of tidal flat macrobenthos communities to the changing environment including mild winters in succession.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2003년도 학술발표회논문집(1)
• /
• pp.151-158
• /
• 2003

Recently, there has been considerable interest in the influence of El Nino/Southern Oscillation (ENSO) on a global scale. ENSO has been measured by a simple index called Southern Oscillation Index (SOI). The statistical characteristics of SOI have been also focused to reveal the influence of ENSO. The SOI trend shows that El Nino events are generally getting stronger and more frequently occurring than La Nina events. However, the variation of SOI has varied significantly in a long-term. The SOI values are computed using the mean value and its standard deviation of the base period from 1951 to 1980. In the present study, the different base periods are applied to compute the SOI values and the influence of the different base periods is investigated in detail to reveal the long-term variation of SOI From the results, we could conclude that the present SOI should be carefully considered as a criterion to judge whether the El Nino and La Nina events are occurring.

• 보건행정학회지
• /
• 제28권3호
• /
• pp.257-262
• /
• 2018

This study reviews the advent of long-term care (LTC) hospitals and its key issues in Korea. For analysis, enforcement ordinances and enforcement rules related to LTC hospitals were reviewed. Official statistic data were used for quantitative analysis and Organization for Economic Cooperation and Development data were utilized for comparative analysis. Various references and expert interviews were conducted for status analysis. As of 2016, the number of LTC hospitals was 1,386 and the number of beds were 246,373. It showed the trend of increasing medical care costs and the cost of care at LTC hospitals increasing from 998.8 billion Korean won in 2008 to 4,745.6 billion Korean won in 2016, accounting for 7.3% of the total National Health Insurance expenditure. From the societal perspective, several issues were pointed out within the current health care system related to LTC hospitals: establishment of roles, concerns about the increase in medical expenses, and the quality of medical personnel.

• 한국대기환경학회지
• /
• 제12권4호
• /
• pp.473-478
• /
• 1996

Using data observed from 1966 to 1994, long-term trends of visibility at 15:00 in Seoul and Chunchon were analyzed. Annual average visibility in Seoul has been decreased continuously. In particular, annual number of days for visibility more than 15km was remarkably reduced since 1980. Also, the trend of the visibility in Chunchon was similar to that of Seoul. But the variations were small to compare with Seoul. Long-term trends of relative humidity (RH) and specific humidity (q) at 15:00 in Seoul have been slightly decreased. Cumulative frequency distributions of visibility for ranges of RH (0 $\sim 50%, 50 \sim 60%, 60 \sim 70%, 70 \sim 80%, 80 \sim 90%, 90 \sim 100%$) at 15:00 in Seoul and Chunchon were generally decreased during the second period (1984 $\sim$ 1994) as compared with the first period (1973 $\sim$ 1983), except for the range of 90 to 100% RH. Despite of decreasing phenomena of RH, characteristics of urban climates in Seoul, visibility degraded due to an increase of air pollution.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1998년도 하계학술대회 논문집 C
• /
• pp.1163-1165
• /
• 1998

This paper presents a method of the regional long-term load forecasting considering economic indicator with the assuption that energy demands proportionally increases with the economic indicators. For the accurate load forecasting, it is very important to scrutinize the correlation among the regional electric power demands, economic indicator and other characteristics because load forecasting results may vary depending on many different factors such as electric power demands, gross products, social trend and so on. Three steps are microscopically and macroscopically used for the regional long-term load forecasting in order to increase the accuracy and practically of the results.

• Journal of Microbiology and Biotechnology
• /
• 제29권2호
• /
• pp.292-296
• /
• 2019

Soils amended for long-term with high levels of compost demonstrated greater abundance of bacterial members of the phylum Bacteroidetes whereas a decreasing trend in the relative abundance of phylum Acidobacteria was noted with increasing levels of compost. Metabolic profiles predicted by PICRUSt demonstrated differences in functional responses of the bacterial community according to the treatments. Soils amended with lower compost levels were characterized by abundance of genes encoding enzymes contributing to membrane transport and cell growth whereas genes encoding enzymes related to protein folding and transcription were enriched in soils amended with high levels of compost. Thus, the results of the current study provide extensive evidence of the influence of different compost levels on bacterial diversity and community structure in paddy soils.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 1996년도 사용종료 매립지의 안정화 에 관한 국제 세미나
• /
• pp.1-40
• /
• 1996

In order to determine the proper treatment of the finished landfill, it is important to predict the trend and stability of the major sources of contaminant in the landfill. In this paper the fate of contaminant sources in the landfill is studied from various literatures by grouping the contaminants into waste, leachate, and landfill gas. One example site referred is Nanji landfill which is one of the representative finished landfills in our country and the trend of contaminant sources in this landfill at current stage is discussed.

• 한국방재안전학회논문집
• /
• 제6권3호
• /
• pp.49-57
• /
• 2013

본 연구에서는 재난환경변화에 대응하여 인적재난 중장기 계획과 로드맵 수립을 기획하기 위하여 국내외 인적재난 안전기술 개발동향을 분석하여 중장기 로드맵을 제시하였다. 최근 국내에서는 재난환경에 연관된 사회환경, 생활환경, 국내외 정부부처 대응 등의 급변화 의하여 인적재난 연구개발 중장기 로드맵 수립의 필요성이 높아지고 있다. 미국은 국가재난 대응계획(NRF)과 국가사건사고관리시스템(NIMS)과 인적재난별 대응 시나리오 등에 의하여 기반을 구축하여 체계적인 연구를 진행하고 있으며, 일본은 년도별 방재백서의 연구개발 계획 등에 의거하여 재해대응 연구개발이 진행되고 있으며, 국내에서는 소방방재청과 국립재난안전연구원이 협력하여 인적재난 분야에 대한 연구과제를 진행하고 있다. 본 연구에서는 인적재난 연구개발 중장기 로드맵을 제시하여, '인명 및 재산피해를 최소화' 하고, 국가적 인적재난 분야 연구개발체계를 정립하고, 나아가 미래 인적재난환경 급변화에 대한 대책을 제시하였다.

• 한국습지학회지
• /
• 제24권4호
• /
• pp.301-311
• /
• 2022

본 연구는 장기 수질모니터링 자료를 이용하여 수질의 계절적 특성을 분석하는 것이 목적이다. 낙동강수계에서 장기 모니터링이 수행되고 있는 34개 지류에서의 모니터링 자료를 이용하여 수질의 계절적 특성을 분석하였고 계절적 분석을 위해 수질의 평균 자료 분석과 변동계수(Coefficient of variation) 분석, 추세분석을 수행하였다. 변동계수 평가결과, 지류가 본류보다 크고 계절적으로는 BOD와 T-P, TOC는 가을철이 크고 T-N은 봄철이 크게 나타났다. 추세분석은 Mann-Kendall과 Sen's Slope를 통해 분석하였으며 BOD와 T-N, T-P는 감소 경향이 많으나 TOC는 증가 경향이 많았다. 또한, 공간적으로는 낙동강 상류보다 하류에서의 증가하는 경향이 많이 나타났다. 본 연구를 통해 장기 수질모니터링 자료의 활용성 평가 및 계절적 특성을 분석할 수 있었고 유역관리를 위해 수질의 안정화 시기, 오염원 증감 변화를 분석할 수 있었다.