• 대한환경공학회지
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• 제28권2호
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• pp.117-127
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• 2006

최근에 국제물협회(IWA)는 수도서비스분야에 대한 새로운 수행능지표를 제안하였고 이의 성공적인 적용사례가 연이어 보고되고 있다. 이들 보고에 따르면, 특히 급수전당의 물소비량이 크게 차이나는 지역들 간에는 백분율을 이용한 지표를 이용하여 수행능을 비교하지 말아야 한다고 말하고 있다. 그러나 아직까지 한국에서는 백분율을 이용하는 지표들 중의 하나인 유수율이 수도행정의 목표를 수립하기 위해 가장 중점적으로 사용되고 있으며, 시스템간의 물손실관리 수행능을 비교평가 하는 데에 널리 사용되고 있다. 이에 본 연구에서는 전국적인 상수도 및 지역통계 자료를 이용하여 백분율지표의 비합리성을 밝히고 보다 효율적인 물손실관리를 위하여 어떤 것이 보다 바람직한 수행능지표인지를 제안하고자 하였다. 3년간의 상수도 및 지역통계 자료를 이용하여 전국의 도시지역에 대하여 유수율, 실손실율, 1인 당 실손실량, 급수전 당 실손실량, 및 IWA의 누수평가지표(ILI)를 산정하고, 각 대상지역을 비교 평가한 결과에 따르면, 백분율을 이용한 지표 즉, 유수율 및 실손실율은 지역 조건이 크게 차이나는 곳 간의 수행능을 제대로 비교하지 못하는 반면, 급수전 당 실손실량 및 누수평가지표는 수행능을 효율적으로 비교, 평가하는 것으로 나타났다. 또한 유수율이 높게 나타나는 지역에서도 하나의 급수전 당 손실되고 있는 물의 양이 매우 클 수 있다는 것을 보여주었다. 따라서 수도사업자의 물손실 관리에 대한 수행능을 보다 합리적으로 평가하여 물손실 문제에 쉽게 접근하고, 문제를 효율적으로 해결하기 위해서는 급수전 당 실손실량 혹은 누수평가지표를 이용하는 것이 바람직하다고 판단된다.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2002년도 학술발표회 발표논문집
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• pp.49-52
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• 2002

Measuring of Water Losses in irrigation canals have been done in 4 irrigation area. Four concrete canals and nine earth canals have been measured by the inflow-outflow method. The results obtained in this experiment were that the loss rates in the main irrigation canal and the secondary irrigation canal were 11.54%, 19.29% respectively. And the loss rates in concrete irrigation canals were 4.77%.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회 논문집(II)
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• pp.925-928
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• 2000

In this paper, physical properties of cement mortar for floor using expansion agent are discussed varied with mixing time and curing temperature, delivery time and content of added water for preventing fluidity loss. According to experimental results, slump loss shows high with elapse of time And as curing temperature goes up, it also show high when curing temperature goes up and time lag between mixing and casting increases. As curing temperature goes down, drying shrinkage shows to be decreased. But it shows decline tendency with increase of added water content.

• 콘크리트학회지
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• 제4권2호
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• pp.119-126
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• 1992

고강도 시멘트 복합체의 유동성 손실을 감소시키기 위한 연구의 일환으로 시멘트계 입자에 대한 고성능감수제의 흡착특성, 현탄액 속에서의 응집특성을 관찰하여 시멘트풀과 모르터의 유동성과 관련시켜 고찰하였다. 본 연구결과 알루미네이트계 화합물이 많이 함유된 보통포틀랜드 시멘트의 흡착률이 가장 크며, 시멘트풀 및 모르처의 유동성 손실이 작았으며 나프탈린계 고성능 감수제가 유동성 손실면에서 얼마간 유리하였다.

• 한국수산과학회지
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• 제48권6호
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• pp.876-882
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• 2015

The aim of this study was to investigate changes in the biochemical characteristics of the Pacific oyster Crassostrea gigas in response to boiling water bath ($85^{\circ}C$, $100^{\circ}C$) and autoclaving ($100^{\circ}C$) heat treatments for 5, 10, 15, and 20 min. The weight loss (7.6-9.5%) of oysters exposed to a $100^{\circ}C$ boiling water bath for 15 min was lower compared to those receiving no treatment. Oysters exposed to the $100^{\circ}C$ boiling water bath for 20 min lost 27.8% of their total weight. The $100^{\circ}C$ autoclaving treatment resulted in weight loss of 13.0-26.1%, with the highest weight loss occurring after 10 min of treatment (26.1%). Heat-treated oysters had significantly higher levels of crude lipid and crude protein relative to untreated oysters (P<0.05). In the heat-treated oysters, total amino acids (including proline and glutamic acid) were increased, but they were decreased by the 20-min $100^{\circ}C$ boiling water bath and autoclaving treatments. The fatty acid composition of oysters was not significantly affected by the water bath heat treatment, but oysters treated with $100^{\circ}C$ autoclaving for 20 min had decreased polyunsaturated fatty acids. Oysters exposed to the water bath heat treatment had significantly increased vitamin A content, but $100^{\circ}C$ autoclaving for 20 min was associated with reduced vitamin A content, as compared to all of the other heat treatments. Therefore, oysters were affected by heat treatment, undergoing metamorphosis and weight loss, but nutrient quality did not change significantly compared to controls, except with the 20-min $100^{\circ}C$ boiling water bath and autoclaving treatments.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1994년도 가을 학술발표회 논문집
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• pp.65-70
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• 1994

The aim of this study is to develop the High Workable Concrete which has not so large slump loss with time using blast-furnace cement and High range water reducing agent. Normal portland cement and blast-furnce cement was used as binders and water-binder ratio were ranging from 34% to 50%. 5 kinds of Superplasticizer and High range water reducing agent were used. Test results show that the blast-furmace cement was much higher flowability than normal portland cement and domestic High rang water reducing and AE agent had very small slump loss than others. The compactability of High Workable Concrete was also confirmed using model wall-form.

• Spatial Information Research
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• 제15권3호
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• pp.291-299
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• 2007

강원도 지역은 매년 다양한 재해를 반복적으로 겪고 있으며 이러한 재해는 이 지역의 지속적인 발전에 장애요인이 되고 있다. 특히 2002년 태풍 루사에 의한 집중호우는 막대한 피해와 더불어 우리사회의 많은 교훈을 남겼다. 본 연구에서는 홍수 유출량을 경제적 관점에서 평가함으로써 수자원 관리의 중요성을 부각하고자 하였다. 그 결과 2002년 루사 당시 삼척시 오십천의 홍수유출에 따른 수자원의 경제적 손실은 약 5천 5백만원이 유실된 것으로 분석되었다.

• 상하수도학회지
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• 제19권3호
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• pp.312-317
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• 2005

The 15 month pilot study was performed to investigate the effect of pretreatment by monochloramine ($NH_2Cl$) on the performance of RO membranes made of cellulose acetate (CA) and polyamide (PA). Both RO membranes experienced severe biological fouling without any pretreatment during the treatment of highly organic surface water in Florida, USA. Feed monochloramination at 5 mg/L significantly minimized productivity loss by effective control of biofouling. The CA membrane did not show any structural damages by monochloramine, while the PA membrane suffered from a gradual loss of membrane integrity by chlorine oxidation, which was characterized as an increase in productivity and a decrease in selectivity. The degradation of PA membrane increased with increasing monochloramine dose.

• Nuclear Engineering and Technology
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• 제26권4호
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• pp.570-577
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• 1994

The loss of water in the carbon steel balls and water region of the end shield for CANDU 6 reactor could lead to significant temperature gradient through the end shield structure which amy result in the excessive deformation. With an assumed end shield drained scenario, the heat deposition rates were calculated through the end shield associated with the central fuel channel during full power operation as an initial step to thermal stress analysis. The drained case was compared with that of water present normal case in therms of heat deposition rater and the total heating throughout the end shield regions. The compared results show that the heat deposition and the total heating remain almost the same between the two cases. It was found that the change of volume integrated flux in the end shield regions due to the loss of water contribute a negligible effect on the heat deposition in this region.

• Computers and Concrete
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• 제32권6호
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• pp.615-623
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• 2023

Crack detection is an essential method to ensure the safety of dam concrete structures. Low-quality crack images of dam concrete structures limit the application of neural network methods in crack detection. This research proposes a modified attentional mechanism model to reduce the disturbance caused by uneven light, shadow, and water spots in crack images. Also, the focal loss function solves the small ratio of crack information. The dataset collects from the network, laboratory and actual inspection dataset of dam concrete structures. This research proposes a novel method for crack detection of dam concrete structures based on the U-Net neural network, namely AF-UNet. A mutual comparison of OTSU, Canny, region growing, DeepLab V3+, SegFormer, U-Net, and AF-UNet (proposed) verified the detection accuracy. A binocular camera detects cracks in the experimental scene. The smallest measurement width of the system is 0.27 mm. The potential goal is to achieve real-time detection and localization of cracks in dam concrete structures.