• The Journal of Engineering Geology
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• v.16 no.1 s.47
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• pp.69-83
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• 2006

This study aims to evaluate a complex groundwater flow system around the underground oil storage caverns using the concept of hydraulic compartment. For the hydrogeological analysis, the hydraulic testing data, the evolution of groundwater levels in 28 surface monitoring boreholes and pressure variation of 95 horizontal and 63 vertical water curtain holes in the caverns were utilized. At the cavern level, the Hydraulic Conductor Domains(fracture zones) are characterized one local major fracture zone(NE-1)and two local fracture zones between the FZ-1 and FZ-2 fracture zones. The Hydraulic Rock Domain(rock mass) is divided into four compartments by the above local fracture zones. Two Hydraulic Rock Domains(A, B) around the FZ-2 zone have a relatively high initial groundwater pressures up to $15kg/cm^2$ and the differences between the upper and lower groundwater levels, measured from the monitoring holes equipped with double completion, are in the range of 10 and 40 m throughout the construction stage, indicating relatively good hydraulic connection between the near surface and bedrock groundwater systems. On the other hand, two Hydraulic Rock Domains(C, D) adjacent to the FZ-1, the groundwater levels in the upper and lower zones are shown a great difference in the maximum of 120 m and the high water levels in the upper groundwater system were not varied during the construction stage. This might be resulted from the very low hydraulic conductivity$(7.2X10^{-10}m/sec)$ in the zone, six times lower than that of Domain C, D. Groundwater recharge rates obtained from the numerical modeling are 2% of the annual mean precipitation(1,356mm/year) for 20 years.

• Journal of agricultural medicine and community health
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• v.3 no.1
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• pp.5-9
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• 1978

이제까지 알려진 바에 의(依)하면 우리 나라에서 간(肝) 및 폐(肺)디스토마 분포양상(分布樣相)은 강원도지역(江原道地域)이 가장 저율(低率)로 나타난 것을 볼 수 있다. 그 이유(理由)로서는 이들 양흡충은 반드시 제(第)1 및 제(第)2중간숙주(中間宿主)를 통한 生活環(생활환)이 완성(完成)되어야만 하는데, 이들 중간숙주분포(中間宿主分布)가 강원도지역(江原道地域)이 낮은 까닭인듯 하다. 우연(偶然)한 기회(機會)에 저자(著者)는 강원도(江原道)의 일부지역(一部地域)은 폐(肺)디스토마의 감염(感染)이 적지 않다는 정보(情報)를 입수(入手)하고 이에 흥미(興味)를 갖게 되었으며, 특(特)히 농후감염지역(濃厚感染地域)으로 예상(豫想)되는 횡성군(橫城郡)의 일부지역(一部地域), 폐(肺), 청일면(廳日面) 신대리(里) 일대(一帶)와 서원면(面) 유현리(里)에서의 간(肝) 및 폐(肺)디스토마의 감염상(感染相)을 파악(把握)할 목적(目的)으로 본(本) 조사(調査)를 전도(全圖)하였다. 검사방법(檢査方法)으로는 일단(一旦) 간(肝) 및 폐(肺)디스토마의 VBS 항원(抗原)으로 피내반응검사(皮內反應檢査)를 실시(實施)하여 간(肝)디스토마 피내반응검사(皮內反應檢査)에 대(對)해서는 객담검사(喀痰檢査)와 면역혈청반응으로 보체결합반응(補體結合反應), 간접형광항체반응(間接螢光抗體反應) 및 Ouchterlony 반응(反應)을 하여 좀더 정확(正確)한 감염상황(感染狀況)을 파악(把握)하고저 하였다. 그 결과(結果)의 개요(槪要)는 아래와 같다. 1. 횡성군(橫城群) 신대리(里)와 우현리(里)의 주민(住民) 680명(名)에 대(對)한 폐(肺)디스토마의 VBS항원(抗原)에 의(依)한 피내반응양성율(皮內反應陽性率)은 12.4%이었고 간(肝)디스토마의 피내반응양성율(皮內反應陽性率)은 12.5%이었다. 2. 성별(性別)에 따른 피내반응양성율(皮內反應陽性率)의 차이(差異)는 간(肝)디스토마의 경우, 여자(女子) 7.4%에 비(比)하여 남자(男子)가 17.1%이었고, 폐(肺)디스토마의 경우는 여자(女子)가 20.7%인데 반(反)하여 남자(男子)가 42.9%로서 2배(倍) 이상(以上)의 고율(高率)이었다. 3. 연령별(年令別)로 보면, 간(肝)디스토마 피내반응양성율(皮內反應陽性率)은 31~40재(才)가 22.1%로 가장 고율(高率)이었고, 폐(肺)디스토마 양성율(陽性率)은 21~30재(才) 사이가 58.5%로서 가장 높았다. 4. 폐(肺)디스토마 피내반응양성자(皮內反應陽性者)에 대(對)하여 객담검사(喀痰檢査)를 실시(實施)한 바 105명(名) 중 11명(名)(10.5%)의 충란검출자(蟲卵檢出者)를 볼 수 있었다. 또 이들에 대(對)한 면역혈청반응(免疫血淸反應)으로 보체결합반응(補體結合反應), 간접형광항체반응(間接螢光抗體反應) 및 Ouchterlony 반응(反應)을 실시(實施)한 바, 각각 42.5%, 50.3% 및 45.8%로서 거의 일치(一致)된 성적(成績)을 나타내어 피내반응양성자(皮內反應陽性者)의 약반수(約半數)에서 이들 혈청반응(血淸反應)이 양성(陽性)으로 나타났다.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.34 no.4
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• pp.26-36
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• 2016

This study aims to identify the place and location of Gasan around Cheonggyecheon in the Joseon Dynasty, and also to examine the current status of their changes or disappearance in the process of modernization. On top of literature research on old document and maps related to dredging of Cheonggyecheon, the field survey to understand the actual status and location of Gasan was conducted. The study contents are like below. First, through old document and maps related to Cheonggyecheon in the Joseon Dynasty, the contents and records related to Gasan around Cheonggyecheon were selected. Such Gasan were mainly built up by dredging work of branch/streamlet in the era of King Sejong, and also the large-scale dredging during the period of King Yeongjo. Second, the location of Gasan and forest around Cheonggyecheon shown in old maps was understood. With Ogansumun(Five-arched Floodgates) as the center, they were constructed on both hills of Cheonggyecheon inside/outside of the capital city, and its surrounding branches. Third, based on the measures to create a scale map based on Susunjeondo, the location of Gasan on old maps was found on the current map, and then the current status of places expressed as Gasan was surveyed. In the results of the study, even though most of the Gasan built up around Cheonggyecheon in the Joseon Dynasty have disappeared by the urban development performed since the end of 19th century, still, there are some remains left.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.447-447
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• 2016

홍수 시 하천을 따라 유하되는 유송잡물(잡목, 생활쓰레기 등)은 구조물에 집적이 이루어지며 이로 인해 물의 흐름을 방해하고 구조물 주변의 지반을 약화시키거나 월류로 인해 심각한 피해를 야기 시킨다. 교량의 경우 유송잡물의 집적은 교각의 항력을 증가시켜 전도파괴를 유발시킬 수 있으며, 교각주변 흐름교란을 통한 하상세굴로 인해 기초부를 파괴시키기도 한다. 또한 통수단면적 증가로 인해 높아진 수위는 제방을 월류시켜 재산 및 인명피해를 유발하기도 한다. 암거의 경우 유송잡물을 포함한 토사로 인해 단면폐색 및 침식으로 암거의 파괴를 발생시키고 이로인해 도로의 단절을 가져오기도 한다. 이러한 유송잡물에 대한 차단대책은 현재 까지 유지관리를 통한 방법만이 최선책으로 제시되고 있다. 본 연구는 국외에서 소개되고 있는 유송잡물 피해저감시설을 대상으로 축소모형실험을 통해 효과를 확인하고 이를 통해 저감시설의 효율에 대해 소개하고자 하는 것이 주목적이다. 유송잡물 저감시설은 교량의 경우 수직분리대 방법, 우회말뚝 방법, 스위퍼를 이용한 방법으로 소개하고 있으며 이들 방법의 특징은 유송잡물 우회를 통해 집적을 저감하는 방식이다. 암거의 경우 수직분리대 방법, 스크린 방법, 우회스크린을 이용하는 방법 등이 있으며 수직분리대는 교량과 마찬가지로 우회방식을 기본방식으로 스크린 방식은 유송잡물의 차단을 원칙으로 하고 있다. 실험의 결과는 교량과 암거의 차단시설 유무에 따른 유송잡물의 집적률을 대상으로 하였다. 차단시설이 없는 경우 교량에서의 집적률은 97.9% ~ 99.2%의 집적률로 나타났다. 수직분리대의 경우 유송잡물 집적률은 49.3%, 우회말뚝은 0.0% ~ 4.2%의 범위로 매우 높은 차단효과를 보이고 있었다. 스위퍼방식의 경우 집적률은 5.3% ~ 20.9%로 나타났다. 이러한 결과로 판단하였을 때 차단시설 설치로 인한 교량에 대한 직접적인 차단효과는 수직분리대 < 스위퍼 < 우회말뚝 순으로 높은 차단효과를 보이는 것으로 나타났다. 그러나 우회말뚝에서의 집적률이 한계치를 넘어선다면 유송잡물로 인해 흐름교란, 수위 및 하상변동, 말뚝의 유실 등으로 인한 피해가 예상된다. 암거대상 유송잡물 차단시설 실험결과는 수직분리대의 경우 type과 투하방법에 따라 차이가 있지만 집적률은 14.7% ~ 64.9%의 범위로 나타났다. 스크린과 우회스크린 방식은 유송잡물의 우회가 아닌 차단이 목적이므로 유송잡물 집적에 의한 수위상승이 우려되는바 수위영향을 검토하였다. 검토결과 스크린 설치로 인한 수위상승이 우회스크린보다 높게 상승하는 것으로 나타났다. 이러한 결과는 스크린의 형태적인 측면에서 2면을 통해 집적되는 특성을 갖는 우회스크린이 통수단면적을 많이 확보하기 때문이다. 따라서 국부적인 수위상승으로 인한 피해를 저감하기 위해서는 설치여건이 허용된다면 통수단면적 확보가 유리한 우회스크린 설치가 유리할 것으로 판단된다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.8 s.99
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• pp.797-802
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• 2005

In this paper, we design a UHF band RFID tag antenna which is conjugate matched to an impedance of a chip and also mountable on conductive materials. The proposed tag antenna is very compact($50{\times}30{\times}4mm$) with a modified PIFA shape. The proposed tag antenna has an advantage of easy matching to various chip input impedances. The performance of the antenna is evaluated by monitoring RCS in the reader direction. The RCS of the designed tag is $-10.2\;dBm^2$ when the chip is shorted and is $-21\;dBm^2$ when the chip impedance is a complex conjugate of the antenna impedance.

• Composites Research
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• v.15 no.2
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• pp.18-23
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• 2002

The absorption and the interference shielding of the problems thor both commercial and military purposes. In this study, the minimization of the electromagnetic wale reflections using composite layers with different dielectric properties was performed. Dielectric constants were measured for glass/epoxy composites containing conductive carbon blacks and carbon/epoxy fabric composites. Using the measured permittivities of the composites having various carbon black contents, the optimal electromagnetic wave absorbing structure in X-band(8.2GHz-12.4GHz) was determined. The optimal multi-layered composite plates have the thickness of 2.6mm. The maximum reflection loss is -30dB at 10GHz, and the bandwidth haying the absorptivity lower than -l0dB is about 2GHz.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.15 no.4
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• pp.197-206
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• 2003

A new type of breakwater, which can be applicable to soft ground without special treatment because of its light self weight and structural characteristic of bottom wall, has recently been developed. The objective of this study is to propose an evaluation method of safety factor for the new type of breakwater considering 3 categories of sliding, overturning, and bearing capacity. Previous method for gravity type of breakwater was modified and the proposed method was verified by comparing the safety factors with maximum lateral displacements, which were obtained from finite element analysis for various types of breakwaters and ground conditions. The results showed the newly proposed evaluation method of safety factors could reasonably be utilized.

• Horticultural Science & Technology
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• v.16 no.3
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• pp.352-354
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• 1998

A soilless culture system with the precise control of nutrient solution was developed and the time changes of ionic contribution to EC reading was analyzed. The measuring device designed was able to wash electrodes cleanly and to measure the pH and EC of nutrient solution stably in the box. The nutrient supply system using metering device was also able to control the EC and pH within ${\pm}0.05mS/cm$ and ${\pm}0.05$, respectively. Under the EC control, activity coefficients of all ions decreased with time as ionic concentrations of $SO_4$, Mg and Ca increased due to the selective nutrient absorption by plants. Time changes of ionic contribution to EC reading could be calculated using equivalent ionic conductivities and activity coefficients obtained by numerical analysis.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.3
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• pp.104-109
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• 2010

The fatality of pedestrian accounts for about 21.2% of all fatality at 2007 year in Korea. In car to pedestrian accident it is very important to inspect the throw distance of pedestrian after collision for exact reconstructing of the accident. The variables that influence on the throw distance of pedestrian can be classified into the factors of vehicle and pedestrian, and road condition. It was simulated by PC-CRASH, a kinetic analysis program for a traffic accident in sedan type vehicle and SPSS program was used for regression analysis. From the results, the throw distance of pedestrian increased with the increasing of vehicle velocity, and decreased with the increasing of impact offset. Also it decreased with the increasing of velocity of pedestrian at accident, and throw distance at the road condition of wet was longer than that at dry condition. Finally, the regression model of sedan type vehicle on the throw distance of pedestrian was as follows; $$dist_i=2.39-0.11offset_i+0.59speed_i-545height_i-0.25walk_i+2.78wet_i+{\epsilon}_i$$.

• Journal of the Korean Society of Groundwater Environment
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• v.4 no.4
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• pp.223-230
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• 1997

DRASTIC system developed by U.S.EPA, is widely used for assessing regional groundwater pollution susceptibility by using hydrogeological factors such as depth to water, net recharge, aquifer media, soil media, topography, vadose zone media, hydraulic conductivity. The system can be applied to site selection of well or waste disposal and landuse for groundwater protection. In this study, hydrogeological spatial database of Younggwang area about topography, drainage, well, geology, soil and landuse was constructed using GIS (Geographic Information System) and regional groundwater pollution susceptibility is analyzed using the spatial database and GIS overlay technique.