• Proceedings of the Korean Geotechical Society Conference
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• 1998.10a
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• pp.329-336
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• 1998

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.210-210
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• 2020

LID (Low Impact Development, 저영향개발)는 산업화 및 도시화 진행 지역에서 비점오염원으로부터 배출되는 오염물질을 제어해 개발지역 내 자연순화 기능을 최대한 유지하고, 물순환 기능증대를 통해 강우 유출수를 지역 내에서 관리하는 것을 목표로 한다. 비점오염원 저감 LID 시설에는 자연형과 장치형 시설이 있다. 자연형 시설에는 저류형, 침투, 식생형 시설 등이 있다. 특히, 침투시설에는 대표적으로 투수블럭이 있으며, 이는 투수성 포장재를 통해 강우 유출수를 지하로 침투시켜 여과나 흡착 등으로 비점오염물질을 제어하는 시설이다. 장치형 시설로는 여과재나 망을 이용해 비점오염물질을 분리하는 여과형 및 스크린형 시설, 응집과 침전을 통해 비점오염물질을 분리하는 응집·침전 시설 등이 있다. 이에 본 연구는 2016년부터 2018년 3년간 전주 서곡지구 지역 내 설치된 필터형 투수블럭, 틈새형 투수블럭에서 진행했다. 각각의 투수블럭에서 총 19회, 20회의 강우 모니터링을 실시했고, 오염물질 유입 및 유출 EMC 등의 분석을 통해 유출 및 오염물질 저감효과를 분석했다. 연구 대상 각 투수블럭의 주요 제원은 시설 용량 14.4㎥, 시설 면적은 14.4㎡이다. 모니터링 결과값을 분석한 결과 필터형 투수블럭의 경우 유출 저감율은 17.4 ~ 100%, 틈새형 투수블럭은 29.6 ~ 100%이었다. 필터형 투수블럭과 틈새형 투수블럭의 단위면적당 유량 저감량은 각각 0.014 ~ 0.583㎥/㎡, 0.035 ~ 0.588㎥/㎡이었다. 오염물질 저감효율을 분석한 결과 유기물 항목(BOD, TOC)의 경우 틈새형 투수블럭에서의 저감효율(BOD 93.59%, TOC 90.39%)이 필터형 투수블럭에서의 저감효율(BOD 89.99%, TOC 86.94%) 보다 다소 높게 나타났다. 영양염류 항목(T-N, T-P)의 경우 필터형, 틈새형 모두 비슷한 저감효율(필터형 T-N 89.02%, 필터형 T-P 98.12%, 틈새형 T-N 90.41%, 틈새형 T-P 98.04%)을 보였다.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.11a
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• pp.64-68
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• 2000

장기간 관측된 지하수위 자료를 시계열분석 중의 하나인 전이함수 모형(Transfer Function - Noise model)을 이용하여 분석하였다. 일반적으로 전이함수 모형은 입력 변수와 출력변수와의 관계가 선형적일 때 적용이 가능하며, 자료가 시간에 대해 연속적으로 존재해야 하는 제한이 있다. 강수량과 지하수위의 변동은 비선형적인 관계를 가지고 있어 이러한 전이함수 모형을 직접 적용하는데는 어려움이 있다. 이러한 비선형성의 정도를 감소시키기 위해 물리모형(HYDRUS)을 이용하여 침투량을 계산하고 이를 입력변수로 사용하여 전이함수 모형을 적용하였다. 침투량을 입력변수로 모형을 추정하였을 때, 강수량을 직접 입력자료로 사용했을 경우보다 ME(mean error), RMSE(root-mean-squre error), MAE(mean absolute error)에서 상대적으로 작은 값을 보여주고 있다. TFN 모형의 모수를 추정하기 위해서 Kalman 필터 알고리즘과 최우추정법(Maximum Likelihood Estimation)을 이용하였다. Kalman 필터 알고리즘을 이용하여 불규칙한 관측주기를 갖는 시계열이나 결측값이 있는 시계열에 대해서도 전이함수 모형을 구하였으며, 이를 통해 결측값에 대한 추정이 가능하였다.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05a
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• pp.611-616
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• 1995

핵연료 피복관의 일차 결함을 통해서 유입되는 냉각수에 의한 피복관 내면의 산화와 이에 따른 수소침투가 핵연료 피복관의 기계적 건전성에 미치는 영향을 규명하기 위한 연구를 수행하였다. 시험 시편은 Westinghouse, NRG, Sandvik에서 제조되는 Zircaloy-4 tube와 Westinghouse사에 개발한 신 합금인 ZIRLO™를 동일한 조건에서 수증기 산화와 수소 주입 실험을 수행하여 제조회사별 성능 평가를 하였으며 기계적 건전성 저하의 평가 방법으로 튜브 파열 실험(tube burst test)을 상온에서 수행하였다. 그 결과는 수소 침투량에 따라 피복관의 기계적 건전성이 지수적으로 감소하는 경향을 보였으며 500ppm이상에서는 취성파괴현상을 보이며 심각한 연성저하를 나타냈다. 제조회 사별 성능 평가에서는 A사 제품이 내식성과 수소흠수특성에서 다른 B, C, D사 제품에 비해 떨어지는 것으로 나타났다.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.411-412
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• 2023

The purpose of this research and development is to develop a structure module that improves the efficiency and constructability of the layout structure as well as the design development of rainwater permeable storage tank blocks using inorganic binders and aggregates with the aim of reducing greenhouse gas (CO₂) with eco-friendly materials. In addition, for the efficient response to flooding of the developed permeable storage structure, we present a technical solution for combining drone mapping technology and flood monitoring technology that can analyze topographical factors in detail.

• Journal of the Korea Concrete Institute
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• v.20 no.3
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• pp.283-290
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• 2008

The repair technique using surface impregnation of reactive compound is so effective for deteriorated concrete structures that many researches are recently focused on these works. Particularly, inorganic impregnant is regarded as ecofriendly material because there is no air-pollution during manufacturing process as well as field coating works. Furthermore, The delamination between old concrete and impregnated surface does not occur, resulting from different material characteristics. In order to evaluate the durability performance of surface-impregnated concrete, durability evaluation through the long-term exposure tests is significant, however, experiments are usually limited to the temporary and qualitative laboratorial scope. In this study, durability characteristics for inorganic and organic/inorganic impregnated concrete specimens are evaluated through longterm chloride exposure test. The specimens with 21MPa and 34MPa strength have been prepared and exposed to chloride attack in the atmospheric, tidal, and submerged conditions. Evaluation for compressive strength, chloride penetration, and electrical potential (half cell potential) for steel corrosion are performed for the specimens exposed for 2 years. From the results, no distinct strength gaining is observed but the resistance to chloride penetration and steel corrosion is evaluated to be improved through surface impregnation. The more improved resistance to chloride attack is measured in the inorganic impregnated concrete and the results from atmospheric condition show more improved resistance to chloride attack than those from submerged and tidal condition.

• Korean Journal of Food Science and Technology
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• v.46 no.6
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• pp.739-742
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• 2014

This study investigated the effect of perforation by the Indian meal moth (Plodia interpunctella) larvae on various flexible food-packaging films, in relation to their thickness and type. Among the various flexible packaging films, polyethylene (PE), aluminum foil (AF), polypropylene (PP), polystyrene (PS), and polyethylene terephthalate (PET) were selected for this study due to their wide usage in food packaging. Based on their thickness, film penetration by P. interpunctella larvae was measured as in following order: PP, $20{\mu}m$; AF, $9{\mu}m$; PET, $12{\mu}m$; PP, $30{\mu}m$; PS, $30{\mu}m$; PE, $40{\mu}m$; PE, $35{\mu}m$; PS, $60{\mu}m$; and PET, $16{\mu}m$. P. interpunctella larvae rapidly penetrated through the packaging films regardless of their thickness and type. In particular, it was observed that PP of $20{\mu}m$ and PS of $30{\mu}m$ were completely penetrated by P. interpunctella larvae within 72 h, rendering thin PP and PS films less valuable as anti-insect packaging films. Our results show that the perforations by P. interpunctella larvae were observed in the thin films. These results imply that each packaging film has a marginal thickness against the perforations by P. interpunctella larvae.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.4A
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• pp.347-353
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• 2009

The qualitative factors influencing the ingress of chloride ion into concrete are water-binder (W/B) ratio, cement type, age, chloride ion concentration of given environment, wet and dry conditions, etc. Thus, an objective of this experimental research is to investigate the effects of cement types and environmental conditions on the chloride ion diffusion characteristics in concrete through the chloride ion diffusion test. For this purpose, the diffusion coefficients for chloride ion in concrete with three types of cement such as ordinary portland cement (OPC), binary blended cement (BBC), and ternary blended cement (TBC), were measured for the concrete specimens with W/B ratios of 32%, 38%, and 43%, respectively. The diffusion coefficients for chloride ion were also measured for the concrete specimens with W/B ratio of 43%, which were subjected to standard curing and field exposure conditions. It was observed from the test results that the resistance against chloride ion penetration increased with decreasing W/B ratio and those of BBC and TBC concretes were greater than that of OPC concrete. Therefore, it was revealed that the use of these cements containing mineral admixtures is required to extend the service life of RC structures exposed to chloride environment. On the other hand, it was noted that the resistance against chloride ion penetration of field exposure test specimens was slightly lower than that of standard curing test specimens due to the penetration of chloride ion under the irregular ambient temperature, splash of wave, and cycle of wet and dry.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.633-636
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• 2008

In order to efficient use of land and development of human, a lot of research on the utilization of underground space is being progress. For the smooth flow of traffic, in the case of mountainous terrain like our country, construction of the tunnel is rapidly increasing. The NATM method is used mainly in the domestic. And also, a lot of research for the NATM is underway, but aspects of the material are lacking. In this study, therefore, it is to evaluate the properties of durability according to mixing ratio and a kind of mineral admixture for the development of shotcrete performance by using the MATM.

• Journal of the Korean Recycled Construction Resources Institute
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• v.1 no.3
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• pp.173-180
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• 2013

This paper is to investigate an effect of waste cooking oil(WCO) on the engineering properties and durability of high volume admixture concrete. Fly ash with 30% and blast furnace slag with 60% were incorporated in OPC to fabricate high volume admixture concrete with 0.5 of W/B. Emulsified refining cooking oil(ERCO) was made by mixing WCO and emulsifying agent to improve fluidity. ERCO was replaced by cement from 0.25 to 1.0%. As results, the increase of ERCO resulted in decrease of slump and air contents. For compressive strength, the use of ERCO led to decrease the compressive strength at 28 days, while it had similar strength or much higher strength than plain concrete at 180 days. Resistance to carbonation and chloride penetration was improved with the increase of ERCO contents due to decreased pore distribution by saponification between ERCO and concrete, while freeze-thaw resistance was degraded due to air loss.