• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.11 s.254
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• pp.1035-1042
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• 2006

An experimental investigation was performed to study two-phase pressure drop of deionized water in a microchannel. Measurement and evaluation of two-phase frictional pressure gradient were carried out using a single horizontal rectangular microchanne1 having a hydraulic diameter of $100{\mu}m$. Tests were performed for mass fluxes of 90, 169, and 267 $kg/m^2$s and heat fluxes of 200-700 $kW/m^2$. Test results showed that the measured two-phase frictional pressure gradient increased with the mass flux and vapor quality. Most macro-channel correlations of two-phase frictional pressure gradient did not provide reliable predictions except under certain limited conditions.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.11 s.254
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• pp.1043-1050
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• 2006

An experimental investigation was performed to study flow boiling heat transfer of deionized water in a microchannel. Measurement and evaluation of boiling heat transfer coefficients were carried out using a single horizontal rectangular microchannel having a hydraulic diameter of $100{\mu}m$. Tests were performed for mass fluxes of 90, 169 and 267 $kg/m^2$s and heat fluxes of 200-700 $kW/m^2$. Test results showed that the measured boiling heat transfer coefficients had no dependence on mass flux and vapor quality. Most macro-channel correlations of boiling heat transfer coefficient did not provide reliable predictions.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.305-312
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• 1996

A 4.1MHz 1H Nuclear Magnetic Resonance (NMR) sensor was designed and manufactured to evaluate the internal quality of fruit. The magnet console having 963 gauss magnetic field induction was used for the NMR sensor. To optimize evaluate the NMR sensor, glycerol and sugar-water solutions were used. 1H(proton) resonance signals were use of to estimate the sugar contents in fruits the proton resonance signals and were validated . The standard errors of predictions(SEP) were 0.565(apple) , 0.394(pear) and 0.415(kiwi) respectively. The result implied that is possible to evaluate apple , pear and kiwi into 3 grades using the NMR sensor.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.260-263
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• 2005

Uncontrolled landfills have been a threat to surrounding environment and human health. To examine the effect of hydrogeological properties on plume migration caused by landfill leachate, two representative landfills in Cheonan and Wonju were selected. In these landfills, seven and eight groundwater wells were installed respectively to monitor water quality and waterlevel, and to perform hydraulic and tracer tests. This study reports preliminary evaluation results including site characteristics, waterlevel measurement and slug tests.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2004.12a
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• pp.127-131
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• 2004

The toxicity of 54 selected process effluents of 16 industry classifications in Korea was evaluated by bioassay test using fish Oryzias latipes, invertebrate Daphnia magna, algae Selenastrum capricornutum and bacteria Vibrio fischeri. Our results demonstrate that the toxicity assessment, such as bioassay test, is effective and of practical use for industrial wastewater management in 54 selected effluents with the limitation of the physico-chemical permit. Among 54 effluents, 4 sample failed physico-chemical permit limitation and 50 passed it. The physcio-chemical measurement items and permit concentrations on the present Water Quality Conservation Act are low related a ecotoxicity.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.975-976
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• 2006

The present paper is a parameter study of zinc flake production using a Simoloyer CM01 horizontal high energy rotary ball mill. The manufactured flakes have a dimension in thickness (t) < $1{\mu}m$ and diameters (d) 5-100 ${\mu}m$, consequently a ratio d/t up to 200. The flake geometry is mainly controlled by the variation of process parameters such as rotary speed of the rotor, ratio of powder/ball charge, load ratio of the system, process temperature, operating model and the quantity of process control agent (PCA). The Zn flakes were characterized by SEM, tap densitometry, laser diffraction and water coverage measurement.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.699-702
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• 2008

In this study, it has observed the precipitation and stage data at each point every ten minutes for gaining the sustainable, reliable and high-quality hydrological data through operating the experimental watershed in mountainous areas such as Gyecheon located in the upstream of Seom river that is the tributary of Nam-Han river. And it has regularly surveyed the runoff and verified the reliability of data using the uncertainty analysis at the gaging station. So, this study has developed the stage-discharge curve(rating curve) and these results are expected to be used as fundamental data for analyzing the circulation of water through surveying evapotranspiration, soil moisture and level of groundwater in watershed.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.10a
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• pp.322-324
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• 2019

하천과 호소수에서 상당 부분의 수자원을 얻는 국내 상황을 고려할 때 하천 수질사고는 심각한 상황을 초래할 수 있다. 이 논문에서는 이동할 수 있는 수질 측정 장치와 측정한 수질 정보를 웹 페이지를 통해 사용자에게 제공하는 시스템을 제안한다. 수질 측정 장치는 모형 배 형태이다. 관리자는 블루투스 통신으로 수질 측정 장치를 조종할 수 있다. 측정한 수질 정보를 와이파이 모듈을 통해 외부 서버의 데이터베이스에 저장한다. 사용자는 웹 페이지를 통해 실시간으로 측정되는 수질 정보를 확인할 수 있다. 구현 결과, 가벼운 무게와 조종 가능한 특성으로 이동성의 개선과 웹페이지를 통한 실시간 시각화를 확인하였다.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.518-522
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• 2015

Green Construction is the construction activities that conserved energy, land, water and material to reduce the negative effect to the environment while assuring essential demand on quality and safety during project construction. This paper critically examine the contribution of awareness and understanding, green construction practices and green construction innovation with the green construction benefits. A measurement model based on the theoretical framework and exploratory factor analysis was developed and tested using structural equation modelling technique. This study employs a survey research methodology involving a total of 346 respondents among construction contractors, developers, clients and consultants in the construction industry. The findings indicate that the awareness and understanding, green construction practices and green construction innovation are significant predictors of the green construction benefits. From the practical perspective, the findings should alert the construction participants on the need of awareness and understanding, green construction practices and green construction innovation towards the green construction benefits. In addition, the findings can be used as diagnostic tool for continuous improvements in the Malaysian construction industry.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.01a
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• pp.165-166
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• 2023

물환경정보시스템에서 하천의 수질을 측정한 자료를 대상으로 DMS(Digital Mosquito Monitoring System)가 설치된 위치와 수질 측정지 위치가 가까운 4개 지점에 대한 수질 측정 성분과 모기지수의 연관성을 분석하였다. 수질 기준 외 측정 성분과 모기지수의 상관관계는 총질소(T-N), 용존총질소(TDN), 인산염인이 연관성이 높은 것으로 나타났다. 이 중에서 인산염인은 모기지수와 양적 선형관계를 이루는데, 인산염은 수중에 부영양화를 일으키는 성분 중 하나다. 수질 측정지는 비료의 영향보다는 오수의 유입으로 인산염이 과잉공급되는 것으로 보였다. 따라서 매년 바뀌는 모기지수 산출식의 지연일자 데이터에 부영양화 지수를 넣음으로써 모기지수의 정확도를 보완할 수 있을 것으로 판단된다.