• 상하수도학회지
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• 제18권6호
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• pp.748-757
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• 2004

In this study, we analyzed the sensitivity of parameters which affect the result of ILLUDAS model, in the various rainfall conditions. The three basins including Namgaja, Kings creek, Gray haven were selected for this research. The rainfall conditions are considered in terms of the rainfall frequency, the duration and the distribution. In most cases, the impermeability area ratio, the sewer slope, and the sewer roughness coefficient give more significant effects on the results than others. The results show that as increasing the rainfall frequency, the sensitivity of the parameters, sewer slope and roughness coefficient are rised, while the impermeability area ratio is decreasing. And also, for the duration of rainfall, the impermeability area ratio's sensitivity shows similar tendency. In case of the rainfall distribution, the parameters of the sewer roughness and the impermeability area ratio show more sensitive in Huff distribution. Especially, The impermeability area ratio is the most sensitive parameter in Central blocking and Yen & Chow distributions respectively.

• 한국콘텐츠학회논문지
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• 제16권4호
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• pp.434-441
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• 2016

본 연구에서는 빅데이터 분석기법을 이용하여 트위터 이용자들을 대상으로 언어에 따른 자기노출과 경계불투과성에 대한 양상을 파악하였다. 6개월 동안 5천4백만 명의 트위터 이용자가 작성한 4억여 개의 트윗을 수집하였으며, 이들 중 트윗 수 상위 10개 언어권 이용자의 프로파일 및 관련 데이터를 조사하였다. 이를 통해 트위터 이용자의 언어가 이용자 프로파일, 프로파일 이미지, 지리정보, URL, 사용자 설명 등 자기정보 공개 항목의 공개비율과 경계불투과성에 미치는 영향을 분석하였다. 분석결과, 경계 불투과성과 자기노출 비율(프로파일, 프로파일 이미지, URL, 이용자 설명, 지리정보)은 언어권에 따라 각각 통계적으로 유의한(p<0.001) 차이가 있는 것으로 나타났다. 자기노출 비율과 평균 점수는 포르투갈어, 인도네시아어 및 스페인어 이용자가 아랍어, 일본어, 터키어, 한국어 이용자에 비해 높은 것으로 파악되었다. 또한 리트윗을 포함한 트윗 수가 많은 이용자일수록 경계 불투과성이 높아지는 것으로 나타났다.

• 한국환경과학회지
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• 제14권11호
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• pp.1005-1014
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• 2005

The purpose of this research was to present multi-criteria which were related to the heat island and find methods which decreased heat island affection on the ecological landscape planning. The results of this study were as follows. According to the analysis of surface temperatures, the first grade was the outside-city like a mountain and its temperature was less than $13.0^{\circ}C$. The fifth grade was the downtown, industrial area and its temperature was more than $26.9^{\circ}C$. Therefore, the result was seen the serious heat-island effect. The results of field survey, the closer to the first grade, the higher the value of green coverage. The closer to the fifth grade, the higher the value of impermeability surface, paving materials and colors. According to the correlation analysis, the temperature had high correlation with impermeability surface, paving materials and colors. According to the simple regression analysis, permeability surface, green coverage, topography, impermeability surface, paving materials f: colors, human impact related with surface temperatures. To plan for the decrease of Heat-Island Effect needed the extension of green space, decrease of impermeability surface. This research suggested data for urban green plan and decrease of heat island effect, but there was a limit to get the objective method for grade classification because of lacking in the basic data, the research of multi-criteria will be accomplished continuously.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.836-843
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• 2009

The Water Glass grouting method has been applied frequently to impermeable grouting in practice. But there is raising problems which are durability decrease by passage time and environmentally adverse effect. So, Earth Natural Grouting method which uses micro cement is developed to overcomes the problems of the Water Glass grouting method. And it is displayed ground injection extent like Water Glass grouting method. For verifying impermeability of ENG, it is carried out a triaxial permeability test about manufacturing specimen of ENG, SGR method which is a presentative Water Glass grouting method. Although Coefficient of permeability, k, of SGR is measured a little high than k of ENG whose value is $a{\times}10^{-6}cm/sec$, the value of ENG belong to impermeable rage. And, k of SGR shows relatively rapid increase according to cure time due to durability decrease of water glass. Also, in-situ test result of ENG has similar value with SGR method for similar ground.

• 한국컴퓨터정보학회논문지
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• 제23권4호
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• pp.25-31
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• 2018

In recent years the privacy issue on social media is often being discussed. The purpose of this study is to explore the relationships among user gender, user group according to user activity level (highly active vs less active) and self-disclosure in social media. We collected a total of 180 million tweets issued by 13 million twitter users for 12 months and investigated attributes of tweet (user's profile, profile image, description, geographic information, URL) which are related to self-disclosure and boundary impermeability. The results show there are significant (p<0.001) interactions between user gender, user group and each attribute of tweet that are related to self-disclosure and show that the patterns of self-disclosure are different across attributes. The results also show that the mean self-disclosure scores and boundary impermeability of top 10% highly active users are significantly higher than other less active users for all genders.

• Elastomers and Composites
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• 제33권3호
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• pp.193-200
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• 1998

고무소재는 다양한 종류별로 구조에 따라 다른 물성을 갖는 것으로 알려져 있다. 일반적으로 EPDM 고무는 내후성과 내오존성이 뛰어나고 열이나 냉기, 습기의 노출에도 잘 견디는 것으로 밝혀진 바 있다. 한편 crosslinked IIR은 물과 기체투과에 대한 저항성이 큰 것으로 알려져 두가지 성분의 장점을 갖도록 EPDM/crosslinked IIR의 블렌드를 새로운 형태의 소재로 추천할 수 있다. 따라서 본 실험에서는 EPDM과 crosslinked IIR의 블렌드비를 변화시키면서 가교시간과 블렌드후 물리/화학적 특성의 개선을 목표로 하였다. 결과적으로 30wt.%의 crosslinked IIR 조성을 갖는 블렌드소재가 내후성, 내오존성 및 내기체투과 특성이 뛰어나, O-링이나 전기관련 제품에 상업적으로 응용가능한 것으로 판단되었다.

• 농업과학연구
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• 제16권1호
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• pp.56-61
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• 1989

1. 콩과식물인 자귀나무와 박태기나무 종자의 발아 및 휴면을 조사해본 결과 자귀나무 종자의 휴면은 종피의 불투수성에 기인하는 것으로 밝혀졌으나, 박태기나무 종자의 휴면은 발아억제물질에 의한 것으로 사료 되었다. 2. 박대기 나무 종자에 함유된 발아억제물질은 온도에 매우 안정적이며 추출직후부터 양상치종자의 말아 및 초기생육시 뿌리의 발육을 적은 량으로도 뚜렷이 억제하는 효과를 나타내었다.

• 한국안전학회지
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• 제31권1호
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• pp.54-60
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• 2016

The bottom of dikes must be kept impermeable to control hazardous chemicals spilled from storage tanks. Currently, insufficient related chemical control laws lead to a possibility to spread through the bottom. Generally, due to the high cost of installation and periodical maintenance, many businesses prefer to install the bottom with general concrete. But, since the impermeability of concrete is dependent on the kind of materials and chemical reaction, all concrete cannot be considered as impermeable material. Thus, it is necessary to make the installation standards of the dike bottom clear in order to avoid the argument over the impermeability and prevent the chemical accident. This study has suggested the standards of impermeable concrete by conducting 7-day exposure test to crude oil with the pilot dikes. The results have showed that the standards have the better impermeable performance compared with the germany standard, which have been penetrated at the maximum penetration depth of 1.9 cm. This study is expected to contribute to both the risk reduction of penetrating into the bottom and the cost reduction of spending to make the bottom of dikes impermeable.

• 한국농촌건축학회논문집
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• 제24권2호
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• pp.45-52
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• 2022

Of the 17,106 domestic reservoirs(as of December 2020), 14,611 are older than 50 years, and these old reservoirs will gradually increase over time. The injection grouting method is most applied to the reinforcement method of the aging reservoir. However, the injection grouting method is not accurate in uniformity and reinforced area. An laboratory model test was conducted to evaluate the applicability of the deep mixing method, which compensated for these shortcomings, as a reservoir reinforcement method. As a result of calculating the hydraulic conductiveity for each method through the model test results, the injection grouting method was calculated as a hydraulic conductiveity value that was about 7.5 times larger than that of the deep mixing method. As a result of measuring the water level change in the laboratory model test, it was found that the water level change decreased in the injection method and deep mixing method compared to the non-reinforcement method. In addition, deep mixing method showed a water level change of about 15% based on 40 hours compared to the injection method, indicating that the water-reducing effect was superior to that of the injection method.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.135-140
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• 2001

This study was developed high-quality a large size precast channel structure using polymer concrete to improve quality of the product as well as to enhance construction quality. Precast PC represent the fastest growing segment of the polymer concrete industry. The fast curing, high strength, and low impermeability permit thin section and rapid reuse of moulds. Developed precast channel structure will be structural experiment and analysis. Also, through an example to construct will be develop the most suitable section survey and make practicable.