The frequent detection and occurrence of micropollutants (MPs) in aquatic ecosystems has raised public health concerns worldwide. In this study, the behavior of 50 MPs was investigated in three different domestic wastewater treatment plants (WWTPs). Furthermore, the Kruskal-Wallis test was used to assess the geographical and seasonal variation of MPs in the WWTPs. The results showed that the concentrations of 43 MPs ranged from less than 0.1 to 237.6 μg L-1, while other seven MPs including 17-ethynylestradiol, 17-estradiol, sulfathiazole, sulfamethazine, clofibric acid, simvastatin, and lovastatin were not detected in all WWTPs. Among the detected MPs, the pharmaceuticals such as metformin, acetaminophen, naproxen, and caffeine were prominent with maximum concentrations of 133.4, 237.6, 71.5, and 107.7 μg L-1, respectively. Most perfluorinated compounds and nitrosamines were found at trace levels of 1.2 to 55.3 ng L-1, while the concentration of corrosion inhibitors, preservatives (parabens), and endocrine disruptors ranged from less than 0.1 to 4310.8 ng L-1. Regardless of the type of biological treatment process such as MLE, A2O, and MBR, the majority of pharmaceuticals (except lincomycin, diclofenac, iopromide, and carbamazepine), parabens (except Methyl paraben), and endocrine disruptors were removed by more than 80%. However, the removal efficiencies of certain MPs such as atrazine, DEET, perfluorinated compounds (except PFHxA), nitrosamines, and corrosion inhibitors were relatively low or their concentration even increased after treatment. The results of statistical analysis reveal that there is no significant geographical difference in the removal efficacy of MPs, but there are temporal seasonal variations in all WWTPs.

이 논문은 기존의 포트폴리오와 관련된 모형에 경기변동(business cycle)과 관련된 변수들을 포함하였을 경우 경기변동이 개인투자자들의 현금 및 주식보유를 통한 자본 이득 극대화와 어떤 관련성이 있는지와 관련된 것이다. 기존 문헌들을 살펴보면, 개인 투자자들은 경기호황기에는 모멘텀 투자와 소형주와 성장주 등에 포트폴리오를 분산 투자하지만 경기가 침체기(recession)에 들어설 경우 수익률이 급등락하는 특성을 지니 는 소형주(small cap)에 집중적인 투자를 하는 성향을 나타내고 있다. 한편 이 논문의 분석결과에 따르면, 경기안정과 금리안정정책, 물가안정 등은 서로 상충관계(trade-off)에 놓여 있음에도 불구하고 코스피수익률과 코스닥수익률에 모두 향후 영향을 미칠 것으로 판단된다. 이는 현재까지의 정책조합(policy mix)보다 더 정 교하고 타이밍을 잘 포착하지 않으면 정책실패에 따른 경기와 물가불안이 동시에 나 타나는 스태그 플레이션(stagflation)으로 이어질 수 있음으로 정책집행의 효율성이 어 느 때보다도 중요해 질 것으로 보인다.

The quantity of the fuel gas consumed are trending upwards because it can be easily delivered but isn't deteriorated and doesn't have any environmental pollution. Though there are many advantages to use the fuel gas, because of its explosiveness and combustibility, it can be hesitate to consume more gas. So paying more attentions to prevent the fuel gas accidents is required. In this paper, we examine the present situation data about the fuel gas accidents and analyze those statistically using ANOVA. we confirm that there is an acceptable difference between the mean values of accidents classified by the kind of gas, the cause, the type and the place but isn't by month. It is expected that our result can be applied as preliminary data when mapping out a strategy for preventing the fuel gas accidents.

The authors analyzed the daily catch data which were obtained from two different regions at the Southern Sea in Korea, Neungpo, Geoje island and Yangwhagum, Namhae island, during three or four years in 1978, 1981-1985, in order to know the fishing characteristics of the set net fisheries. The favorable fishing season was summer in the southern sea. The total catches during one year were greatly affected by those several day when the dominant species of fish were caught in large quantities. The dominant species of fish at Neungpo were little horse mackerel, sand lance, sardine, hair tail, spanish mackerel and common mackerel, and those at Yangwhagun were anchovy, little horse mackerel, sardine, spanish mackerel and gizzard shad, in order of catch. Especially, the little horse mackerel and the sardine appeared to make up very big schools at both Neungpo and Yangwhagum. The occurrence seasons of the dominant species were different by the region, but generally those were earlier at western part than at eastern part of the Southern Sea in Korea.

National parks, which are preserved areas of 6,726.298 km2(3,972.589 km2 on land and 2,753.709 km2, at sea), take up 6.71% of the national territory, and they are classified by type into 17 mountain parks, 4 maritime or coastal parks, and 1 historical site park. Of them all, the maritime or coastal national parks, which are preserved areas covering wide tracts of maritime, lately attract increasing numbers of visitors. In this light, this study identifies the issues with the maritime or coastal national parks such as the changes in the number of visitors and the unbalance involved in the budget execution, based on the visitors to the national parks and the specifics of budget executed for them. On this basis, the study has conducted the research with a view to suggesting improvements for more useful management and operation of the maritime or coastal national parks. As a result, the study has reached the following conclusions. First, to accommodate those who want to visit the maritime or coastal national parks, the tour infrastructure needs to be expanded to guide the visitors’ use of the facilities by focusing on their touring behavior and characteristics. Second, budget should be acquired through diversifying revenue structure to eliminate hugely unbalanced budget. Third, visitors nowadays come to national parks for recreational experience or to tour nature, but the maritime or coastal national parks focus on cultural facilities. To accommodate the visitors’ needs, the parks should get diversified visitor facilities that reflect the regional characteristics.

As the service period of bridges becomes increased the maintenance and management of existing bridges become also more important. Korea Expressway Corporation has collected data on the maintenance for a long period but those obtained data has rarely been thoroughly analyzed for the maintenance purposes. This study investigated the service life of extension joint of bridge among various bridge members and this attempt should be very meaningful as using the data obtained from the field. The service life of the extension joints can be used for the development of maintenance strategy in the future.

VTS의 관제 범위에서 발생한 교통관련사고 분석은 VTS의 개선방향 검토에 중요한 기초 자료를 제공할 것으로 기대되나 현재까지의 연구는 미흡한 실정이다. 분석은 최근 6년(1999-2004년)간의 해양안전심판재결서와 VTS 센터별 자료 및 Port-Mis자료를 이용하여 이루어졌다. 연구결과, 1) 교통관련사고의 통제 및 VTS의 개선 방향을 검토할 필요성을 확인하였다. 2) 교통관련사고의 경우 관제여부에 따라 사고원인과 시정상태, 충돌사고의 상대선 인지거리 및 인지지체원인에 차이가 발생함을 통계적으로 확인하였다. 3) VTS의 지원은 충분한 시간 전에 적극적이고 지속적으로 이루어져야 하며 04-08시 시간대에 강화되어야 함을 확인하였다. 4) 사고예측모형을 통해 관제선박의 교통관련사고는 일평균 교통량에 큰 영향을 받고 있으므로 VTS 운영자가 사고의 위험성이 높은 선박을 우선적으로 식별하여 관련 정보를 신속하고 적극적으로 제공할 수 있도록 지원하는 시스템을 구축하여야 한다.