• Atmosphere
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• v.15 no.2
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• pp.101-118
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• 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
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• v.2 no.2
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• pp.199-209
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• 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.

• Proceedings of the Korea Water Resources Association Conference
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• 2003.05a
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• pp.151-158
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• 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.

• Health Policy and Management
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• v.28 no.3
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• pp.257-262
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• 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.

• Journal of Korean Society for Atmospheric Environment
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• v.12 no.4
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• pp.473-478
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• 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.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.1163-1165
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• 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
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• v.29 no.2
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• pp.292-296
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• 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.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1996.12a
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• pp.1-40
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• 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.

• Journal of Korean Society of Disaster and Security
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• v.6 no.3
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• pp.49-57
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• 2013

This paper is to show the long-term roadmap by analyzing the development trend for the safety technology of facility disaster in the country and abroad, and it is designed to plan the long term and roadmap in response to change the disaster environment. Recently in the country, it is increasing the needs of the long term roadmap design of the facility disaster research development in the facility disaster, by the repidly of the social and the living and the related governments response's changing. The U.S. is going to develop the disaster responding research by planning the its master plans, including the NRF (National Responing Framwork), the NIMS (National Incident Management System), and its sinarios etc.. Japan is going to develop the research planning in the annual report of the disaster prevention, and we going to do the study projects about the facility disaster area with the NEMA (National Emergency Management Agency) and NDMI (National Disaster Management Institute). This paper is showed to design the long term roadmap of the facility disaster's study development, and to minimize the damage of the man and his property, and to set the study development system of the national facility disaster, and furthering to make the resilient planning in changing of the facility disaster's environment.

• Journal of Wetlands Research
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• v.24 no.4
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• pp.301-311
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• 2022

The purpose of this study is to analyze the seasonal characteristics of water quality using long-term water quality monitoring data. Seasonal characteristics of water quality were analyzed using monitoring data from 34 tributaries where long-term monitoring was performed in the Nakdong River system, and average data analysis of water quality, coefficient of variation analysis, and trend analysis were performed for seasonal analysis. For seasonal analysis, average data analysis of water quality, coefficient of variation analysis, and trend analysis were performed. As a result of the evaluation of the coefficient of variation, tributaries were larger than main streams, and BOD, T-P, and TOC were larger in autumn and T-N were larger in spring. Trend analysis was analyzed using Mann-Kendall and Sen's Slope. BOD, T-N, and T-P tended to decrease, but TOC had a lot to increase. Through this study, it was possible to evaluate the availability of long-term water quality monitoring data and analyze seasonal characteristics, and to analyze the stabilization period of water quality and changes in pollutant sources for watershed management.