• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.09a
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• pp.31-34
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• 2001

지하 LPG 저장기지의 수벽시설이 저장공동 주변 암반에 미치는 영향을 진단하기 위해서 수벽시설의 주입압력을 강하시키면서 간극수압계와 관측공에서의 지하수두 변화를 모니터링하였다. 수벽시설의 관측지점에 대한 효율성은 수치해석으로부터 수벽시설과 관측지점간 매질의 확산능을 구함으로써 분석하였다. 확산능 산출결과를 검증하기 위해서 수벽시설의 압력강하에 따른 관측지점에서의 수두강하비와 수두강하율을 구하여 확산능 결과와 비교하였다. 비교결과, 확산능은 수두강하비, 수두강하율과 일관된 변화를 보여주었으며 확산능의 값이 클수록 수벽공의 압력변화에 따른 관측지점에서의 반응성이 양호함을 나타내었다

• Journal of Korean Society of Forest Science
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• v.84 no.4
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• pp.409-414
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• 1995

This study was carried out for the analysis and comparison about the noise diminution effects by the height, width and density of Euonymus japonica wall, the distance of sound source, the distance of sound receiver, the height of sound source, and the height of sound receiver. The results obtained were summarized as follows; 1. After the establishment of tree wall, the volume of noise diminution measured 6.8dB and the effects of noise diminution measured heigher than before by 10.6% and t-value was significant at the 1% level 2. In simple correlation between the effects of noise diminution and variables, the density of tree wall was found as the most significant factor, and the last were found in the order of the distance of sound receiver, the width of tree wall, and the distance of sound source. 3. In partial correlation coefficients the effects of noise diminution and variables, the density of tree wall (r=-0.959) was found as the most significant factor, and the last were found in order of the distance of sound receiver (r=-0.906) and the width of tree wall (r=-0.753). 4. The estimated equation to measure the effects of noise diminution according to variables (the height of tree wall, the width of tree wall, the density of tree wall, the distance of sound source, the distance of sound receiver, the height of sound source, and the height of sound receiver) was $Y=69.520-1.672X_1-1.656X_2-0.066X_3-0.248X_4-3.134X_5-0.222X_6-0.343X_7$, and the coefficient of determination of this estimated equation was highly found as 0.950. 5. In semi-partial correlation coefficient the effects of noise diminution were found in the order of the density of tree wall, the distance of sound receiver, the width of tree wall, and the height of tree wall from the highest to the lowest. Therefore, it was considered that the density of tree wall, the distance of sound receiver, the width of tree wall and the distance of sound source should be controlled effectively to increase the effects of noise diminution by Euonymus japonica wall.

• The Journal of Engineering Geology
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• v.12 no.1
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• pp.35-51
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• 2002

This study aims to establish the methodology for design of an optimum water curtain system of the unlined underground oil storage cavern satisfying the requirements of hydrodynamic performance in a volcanic terrain of the south coastal area. For the optimum water curtain system in the storage facility, the general characteristics of groundwater flow system in the site are quantitatively described, i.e. distribution of hydraulic gradients, groundwater inflow rate into the storage caverns, and hydrogeologic influence area of the cavern. In this study, numerical models such as MODFLOW, FracMan/MAFIC and CONNECTFLOW are used for calculating the hydrogeological stability parameters. The design of a horizontal water curtain system requires considering the distance between water curtain and storage cavern, spacing of the water curtain boreholes, and injection pressure. From the numerical simulations at different scales, the optimum water curtain systems satisfying the containment criteria are obtained. The inflow rates into storage caverns estimated by a continuum model ranged from about 120 m$^3$/day during the operation stage to 130~140m$^3$/day during the construction stage, whereas the inflow rates by a fracture network model are 80~175m$^3$/day. The excavation works in the site will generate the excessive decline of groundwater level in a main fracture zone adjacent to the cavern. Therefore, the vertical water curtain system is necessary for sustaining the safe groundwater level in the fracture zone.

• Proceedings of the Korea Water Resources Association Conference
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• 2001.05a
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• pp.524-529
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• 2001

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2003.04a
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• pp.135-143
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• 2003

• Journal of Korean Society of Forest Science
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• v.78 no.1
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• pp.30-34
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• 1989

Effects on noise attenuation of the hedge species, Thuja orientalis L. and Euonymus japonicus Thunb., widely used as road side hedges, were analysed at the frequencies of 1,000, 2,000 and 3,150 Hz., respectively. The present experiments were carried out both in the field and in a Semianechoic Chamber. As increasing the distances from the noise source, attenuation rates of noise level were increased at high frequencies. But the attenuation rates of the noise level at low frequencies showed varied as the distances increased, and this trend appeared to be caused by the influence of ground waves. Generally, in this experiment, Thuja orientalis L., which is a coniferous species, showed more effective on the abilities of noise attenuation than that of Euonymus japonicus Thunb., which is a broad-leaved evergreen species.

• Landscaping Tree
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• v.81 no.7_8
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• pp.25-28
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• 2004

그간 무궁화 보급운동은 무궁화가 가지고 있는 속성과 품종의 선택, 식재방법 및 관리에 대한 기본 개념이 정립되지 않은 상태에서 추진되어온 결과 다소 잘못된 점이 도출 되었을 뿐 아니라 국민들이 좋아할 만큼 성공되지 못하였다. 세계적으로 무궁화를 가로수나 정원수로 심고 있는 나라는 온대지역에 속하는 대부분의 나라로 알려져 있고 특히 그리스나 이태리에서 주택가나 가로수로 식재되고 있다. 그러나 그 가로수는 우리가 일반적으로 생각하고 있는 느티나무, 은행나무, 버드나무등과 같이 크게 자라는 나무가 아니므로 주택가나 꽃길조성에 식재되어 왔다. 이제 무궁화는 어느 곳이든 잘 자라는 수벽이나 꽃동산으로 이용하고 아무데서나 잘 자란다는 「고정관념」을 버려야 한다.

• KIEAE Journal
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• v.16 no.4
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• pp.63-69
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• 2016

Purpose: This preliminary study investigated a potential of the water wall systems that provide heat storage and natural lighting control simultaneously. Method: In order for transparency of the water wall to be controlled, the study first proposed two measures: to adjust transparency of the water wall; to control transparency of water wall surface. The performance of two measures then was verified and compared by experiments. In addition, a trade-off between heat collect and heat storage resulting from using additive for adjusting transparency was investigated. Result: The experiment showed that the two measures are similar in performance. The investigation of trade-off relation showed the additive should have the same heat storage as the water to prevent decrease in thermal performance of the water wall. As an economical measure to control transparency of the water wall, this study suggested a measure of secondary heat transfer systems using shading device that first absorbs solar radiation and then transfers heat to the water wall. The experiment show that performance of the proposed measure is similar to controlling transparency of water wall surface. In conclusion, it is expected that the performance of the water wall can be economically maximized by using the proposed mean in terms of heating, cooling and lighting energy saving.

• Landscaping Tree
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• s.106
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• pp.34-36
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• 2008

그간 무궁화 보급운동은 무궁화가 가지고 있는 속성과 품종의 선택, 식재방법 및 관리에 대한 기본개념이 정립되지 않은 상태에서 추진되어온 결과 다소 잘못 된 점이 도출 되었을 뿐 아니라 국민들이 좋아할 만큼 성공되지 못하였다. 세계적으로 무궁화를 가로수나 정원수로 삼고 있는 나라는 온대지역에 속하는 대부분의 나라로 알려져 있고 특히 그리스나 이태리에서 주택가나 가로수로 식재 되고 있다. 그러나 그 가로수는 우리가 일반적으로 생각하고 있는 느티나무, 은행나무, 버드나무등과 같이 크게 자라는 나무가 아니므로 주택가나 꽃길조성에 식재 되어 왔다. 이제 무궁화는 어느 곳이든 잘 자라는 수벽이나 꽃동산으로 이용하고 아무데서나 잘 자란다는 "고정관념"을 버려야 한다. 우리가 아름다운 나라꽃을 보기 위하여 무궁화를 심었는데 자라지도 못하고 꽃도 피지 못하여 단지 무궁화나무의 형체만 가지고 있을 뿐 우리가 바라는 꽃나무의 구실을 못한다면 오히려 심지 않은 것만 못하다는 뜻이다. 양적으로 많이 심는 것보다 적은 량을 심더라도 가치 있게 심고 가꾸는 것이 더 중요하다. 그러므로 다음과 같은 적지를 잘 선정하여 심고 항상 충분한 비배관리를 해 주어야 한다.

• Tunnel and Underground Space
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• v.18 no.1
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• pp.80-89
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• 2008

The influence of in-situ rock stress on the stability of an underground rock structure increases as the construction depth become deeper and the scale of a rock structure become larger. In general, hydraulic fracturing stress measurement has been performed in the surface boreholes of the target area at the design stage of an underground structure. However, for some areas where the high horizontal stresses were observed or where the overstressed conditions caused by topographical and geological factors are expected, it is desirable to conduct additional in-situ stress measurement in the underground construction site to obtain more detailed stress information for ensuring the stability of a rock structure and the propriety of current design. The study area was a construction site for the additional underground oil storage facility located in the south-east part of OO city, Jeollanam-do. Previous detailed site investigation prior to the design of underground structures revealed that the excessive horizontal stress field with the horizontal stress ratio(K) greater than 3.0 was observed in the construction area. In this study, a total of 13 hydraulic fracturing stress measurements was conducted in two boreholes drill from the two water tunnel sites in the study area. The investigation zone was from 180 m to 300 m in depth from the surface and all of the fracture tracing works were carried out by acoustic televiewer scanning. For some testing intervals at more than 200 m ind depth from surface, the high horizontal stress components the horizontal stress ratio(K) greater than 2.50 were observed. And the overall investigation results showed a good agreement with the previously performed test.