• 터널과지하공간
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• 제20권3호
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• pp.194-206
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• 2010

울산 태화강 지류인 대곡천변에 선사시대 암각된 것으로 추정되는 반구대 암각화와 천전리 각석이 있다. 이들 암각화군은 중생대 백악기 퇴적암인 셰일면에 새겨져 있어 6000여년 동안 비바람에 풍화되어 풍화 5등급을 넘어 지금은 박리가 되고 있는 상태이다. 더욱이 반구대 암각화는 하류 사연댐의 수몰지구내에 존재하므로 45년 동안 1년 중 168일간은 물속에 잠겨있는 상태를 반복하여 왔다. 본 연구는 암각화군의 공학적 상태를 점검하여 암각화 본체의 강도증진과 풍화정지를 위한 대안을 제시하려는 목적으로 연구를 진행하였다.

• 자원환경지질
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• 제32권3호
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• pp.261-271
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• 1999

Mining activity in the Gubong gold mine started in 1908 and lasted up to recent days. Heavy metals derived from the activity may be porentially toxic to human life and envirinment of this area. Because metal toxicity depends on chemical associations into five operationally defined groups: exchangeable, carbonate, reducible, oxidizable, and residual fractions, and the Most of heavy metals have significant little significance (alomost<1%). And Cu is mainly associated with the oxidizable from. Total concentration of heavy metals, pH, and mineralogy affect the chemical forms of the metals. Heavy metal concentrations. Significant amounts of metal elements (5∼65.1% in Pb, 6.2∼39.7% in Zn, 8.7∼54.7% in Cd, and 3.6∼24.7% in Cu) were present in carbonate form from mine wastes, contaminated soils and sediments. High pH value and cerussite (Pb bearing carbonate mineral) in mine wastes, contaminated soils and sediments. High pH value and cerussite (Pb beraring varbonate mineral) in mine waste support this result. Areas with high corbonate bound from would have higher potentoal conamination, however, because elements of carbonate bound forms are easily mobilized under lower pH conditions in the surface envionments due to acid to rain soil acidification.

• 한국관개배수논문집
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• 제21권1호
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• pp.32-44
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• 2014

In Korea, global warming caused by the climate changes impacted on weather system with increase in frequency and intensity of precipitation, and the rainfall pattern changes significantly by regional groups. Furthermore, it is expected that the regional and annual fluctuation ranges of the rainfall in the future would be more severe. Nowadays, agricultural drainage system designed by the existing standard of 20-year return period and 2 days of fixation time cannot deal with the increment rainfall such as localized heavy rain and local torrential rainfalls. Therefore, it is required to reinforce the standard of the drainage system in order to reduce the agricultural flood damage brought by unusual weather. In addition, it is needed to improve the standard of agricultural drainage design in order to cultivate farm products in paddy fields as facility vegetable cultivation and up-land field crop have been damaged by the moisture injury and flooding. In order to prepare for the changes of rainfall pattern due to climate changes and improve the agricultural drainage design standards by the increase of cultivating farm products, the purpose of this study is to examine the impact of climate changes, the changes of relative design standard, and the analytic situation of agricultural flood damages, to consider the drainage design standard revision, and finally to prepare for enhanced agricultural drainage design standards.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권12호
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• pp.567-572
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• 2002

In these days, diesel vehicle or power plant emits $NO_X\; and SO_2$ which cause air pollution like acid-rain, ozone layer destroy and optical smoke, therefore there are many kinds of methods considered for removing them such as SCR, catalyst, plasma process, and plasma-catalyst hybrid process. T$TiO_2$ is commonly used as catalyst to remove $NO_X$ gas because it have very excellent chemical characteristic as photo catalyst. In this paper, $NO_X$ sensing characteristic of $TiO_2$ thin film deposited by R.F Magnetron sputtering is investigated. A finger shaped electrode on $Al_2$O$_3$ substrate is designed and $TiO_2$ is deposited on the electrode by the magnetron sputtering deposition system. Chemical composition of the deposited $TiO_2$ thin film is $TiO_{1.9}$ by RBS analysis. When the UV is irradiated on it with flowing air, capacitance of $TiO_2$ thin film increases, however, when NO gas is put into the system with air, it immediately decreases because of photo chemical reaction. and it monotonously decreases with increasing NO concentration.

• 한국인터넷방송통신학회논문지
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• 제14권3호
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• pp.81-88
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• 2014

요즈음 교통사고를 줄이기 위하여 IT 기술을 이용한 교통사고 연구가 많이 진행되고 있다. 특히, 고속도로에서 교통사고를 예방하기 위해서 눈이나 비가 올 경우에는, 날씨조건을 고려한 최적의 교통속도를 실시간으로 산출해야한다. 본 논문에서는 교통사고를 예방하기 위하여 결빙 구간 및 안개구간 자동 경고 안내 방송 시스템을 웹기반에서 모의실험 하였다. 뿐만 아니라, 퍼지 추론 규칙을 이용하여서, 최악의 날씨 조건에서도 교통사고를 예방 할 수 있도록, 운전자 에게 최적의 교통 안전속도를 실시간으로 운전자에게 알려 주는 모의실험을 개발하였다.

• 한국물환경학회지
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• 제25권3호
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• pp.411-418
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• 2009

The analysis of characteristics of water use evaluation and nighttime domestic flow evaluation was performed by using result from flow monitoring and surveying water supply records and nighttime domestic flow for a year. The analysis of correlations showed that, for both sites, the infiltration ratio and wastewater flow have shown a good relationship with high correlation factor and that the calculation of wastewater flow was highly affected by monthly rainfall depth as well as number of rain days. From this result, it was concluded that the measurement of infiltration should be performed when the rainfall does not significantly affect the sewer flow. Also, it is notable that each value of calculated using method for infiltration evaluation are not comparable to each other, but independent methods. In selecting of evaluation method for infiltration, therefore, a great emphasis should be imposed to the character of area and the seasonal factor in order to select optimal one. It is desirable way for evaluating infiltration and reduction ratio using result from an optimal method.

• 한국환경과학회지
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• 제23권12호
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• pp.1999-2014
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• 2014

A meteo-tsunami occurred along the coastline of South Korea on 31 March 2007, with an estimated maximum amplitude of 240 cm in Yeonggwang (YG). In this study, we investigated the synoptic weather systems around the Yellow sea including the Bohai Bay and Shandong Peninsula using a weather research and forecast model and weather charts of the surface pressure level, upper pressure level and auxiliary analysis. We found that 4-lows passed through the Yellow sea from the Shandung Peninsula to Korea during 5 days. Moreover, the passage of the cold front and the locally heavy rain with a sudden pressure change may make the resonance response in the near-shore and ocean with a regular time-lag. The sea-level pressure disturbance and absolute vorticity in 500 hPa projected over the Yellow sea was propagated with a similar velocity to the coastline of South Korea at the time that meteo-tsunami occurred.

• 대한공간정보학회지
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• 제11권3호
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• pp.35-40
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• 2003

최근 이상기후에 의한 집중호우와 태풍의 피해는 날로 증가하고 있으며, 이에 대한 대책을 마련하기 위하여 많은 노력을 하고 있다. 특히 GIS를 응용하여 대책을 마련함으로써 신속한 정보의 추출 및 객관적인 분석을 수행할 수 있으므로 그 효과를 발휘할 수 있었다. 이에 따라 본 연구에서는 강우-유출모형과 HEC-RAS를 연계하여 자동으로 모의가 가능하도록 하였으며, 그 결과를 MapObject와 MFC를 이용하여 표현함으로써 위험지구를 쉽게 조회할 수 있으며, 평면도, 종단도, 횡단도를 화면에 동시에 출력할 수 있어서 주위의 피해 상황을 파악하는데 도움을 주어 재해를 미리 예측하고 대비하는데 도움을 줄 수 있을 것으로 사료된다.

• 한국잠사곤충학회지
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• 제40권2호
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• pp.117-125
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• 1998

Entomopathogenic nematodes, Heterorhabditidae and Steinernematidae, were isolated from the soil of mulberry field, and the high infectivity and invesiveness were confirmed in the silkworm, Bombyx mori. The cause of non-microbial and acute flacherie was found as an disease by infection with soil-born nematodes through the mulberry leaves contaminated with soil and rainwater. The causal nematodes were isolated by silkworm trap from all of the 5 soil samples collected on the 5 mulberry fields, and identified as 3 strains of Heterorhabditis sp. and 2 of Steinernema sp. Rainwater itself, however, wasn't engaged in the silkworm disease, mulberry leaves with rainwater was rather profitable for cocoon production when the leaf quality was too hard to feed silkworm. Feeding of wet mulberry leaves with rain might not so harm to silkworm when the condition of rearing room to be kept at suitable temperature and ventilated well. Nematode infection of silkworm could be occurred by harvesting and feeding of contaminated mulberry leaves on the weather condition of rainy and wind. For the prevention of nematode infection, silkworms should be fed the leaves harvested from the higher portion of the mulberry tree in rainy days. For an oppositional application of this susceptibility of silkworms to nematode, might be useful on the collection and amplification of nematode agents for biotic control of pest insects.

• 자원환경지질
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• 제32권1호
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• pp.53-62
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• 1999

The possibility of heavy metal pollution by contaminated roadside soils was studied under controlled conditions. The soil samples from roadside and those from a retention pond consisting of settling particles were characterized by the XRD analyses and the sequential extraction experiments. Characterization by sequential extraction, for roadside soil indicates elevate total concentrations of heavy metals. The leaching behavior of the samples under different pH and time conditions were also studied. Differences between both types of samples result mainly from the buffering effect of carbonates, present in roadside soils and lacking from settling particles. Acid leaching of the settling particles is equivalent to the sum of FI+FII+FIII, while the amounts leached from roadside soil are lower probably from kinetic reasons. The buffering effects of carbonates were found to greatly delay the onset of the leaching reactions and the extent of dissolution in most metals except for Ca and Mn. The study of leaching kinetics at pH of 6.5 and 5 showed that Cd and Zn reached the maximum possible concentration within 3 days, while Pb did not show any sign of dissolution at both ph values. The absolute amounts of dissolved Cd and Zn increased by 7 to 9 times by decreasing the pH from 6.5 to 5, indicating slightly acidified rain may result in significant metal dissolution. As deduced from both sequential extraction and leaching experiments, the relative mobility of heavy metals is found to be : Mn=Cd>Zn>>Pb>Fe, in spite of large differences in heavy metal contents and localizations.