• 한국해안해양공학회지
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• 제5권3호
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• pp.204-211
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• 1993

Laplace 방정식을 Green 공식으로 해석한 경계요소법을 이용하여 수치수조에서 비선형파를 재현하였다. 미지수는 유체영역의 경계에 설정한 각 절점에서의 속도포텐셜과 수면변위이며 이를 구하기 위하여 지배방정식과 자유수면 경계조건을 기본식으로 하는 연립 1차방정식을 구성하였다. 동력학적 자유수면 경계조건에서 속도의 제곱항을 고려하였으며 자유수면 경계에서 속도포텐셜의 연직변화를 고려하여 이의 시간미분을 계산하였다. 본 수치모델을 이용하여 고립파와 Stokes의 2차 파낭을 재현한 결과, 이론치와 매우 잘 일치함을 확인하였다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회(2)
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• pp.1453-1454
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• 2005

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회(2)
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• pp.1281-1282
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• 2005

• 물과 미래
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• 제30권2호
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• pp.34-37
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• 1997

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회(1)
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• pp.125-126
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• 2005

• 한국환경보건학회지
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• 제29권1호
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• pp.8-15
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• 2003

In this study, chlorine dose at water storage tank was predicted to meet the recommended guideline for free chlorine residual in drinking water distribution system, using EPANET which is a computer program that performs extended Period simulation of hydraulic and water quality behavior within pressurized pipe networks. The results may be summarized as follows. The decay of chlorine residual by season varied considerably in the following order; in summer ($25^{\circ}C$) > spring and fall (15$^{\circ}C$) > winter (5$^{\circ}C$). For re-chlorination at water storage tank by season, season-varying chlorine dose was required at its maximum of 1.00 mg/l in summer and minimum of 0.40 mg/l in winter as free chlorine residual. The decay of chlorine residual through out the networks increased with water age spent by a parcel of water in the network except for some points with low water demand. In conclusion, the season-varying chlorine dose as well as the monitoring of water quality parameters at the some points which showed high decay of chlorine residual may be necessary to deliver the safe drinking water.

• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book II
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• pp.218-218
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• 2003

Recently we showed the prototype portable device for the determination of human skin moisture by using near infrared spectroscopy. In order to optimize the acquiring condition of NIR spectrum of skin and control the target information of water depending the site such as epidermis and dermis, skin depth profiling was investigated changing the distance between illuminations and receiving of radiation in the terminal of fiber probe. The colleted light information could be controlled by changing the distance of the fiber optic probes. It was confirmed that the longer distance we used, the deeper site from the skin surface we could get information from in this study. Four kinds of probes with distances such as 0.03 mm, 0.1 mm, 0.5 mm, and 1.0 mm were used. In addition, the gap size from 0.3 mm to 3.0 mm was studied to control the intensity of water absorbance effectively and to avoid saturation of water absorption. We also investigated the reference materials depending the reflectance ratio for water absorption not to be saturated because of the strong absorptivity of water. Furthermore, spectroscopic information regarding free water and bound water around 1850 nm was investigated by using the different distance of fiber optic probes. This study would be great help to control the spectroscopic information of water to be measured depending the site where water exists.

• 약학회지
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• 제24권2호
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• pp.87-95
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• 1980

Chlorination to polluted water can produce chlorocompounds which may impair human health. It has been discussed that chlorophenols would be one of undesirable substances in drinking water. This study was undertaken to investigate the production mechanism of chlorophenols by chlorination in the disinfection of water and to determine pollution levels of phenols as precursor of chlorophenols and chloropbenols in some sewage, stream water and tap water in the vicinity of Seoul from January to September, 1979. By chlorination with hyperchlorite to phenols in distilled water, o-chlorophenol was predominantly produced at the concentration of less than 10ppm of free chlorine. o-Chlorophenol, 2,6-dichlorophenol and 2,4-dichlorophenol were also produced by chlorination with the concenration from 20 to 100ppm of free chlorine. From the concentration of 100ppm of free chlorine to 200ppm, o-Chlorophenol was vanished and 2,6-dichlorophenol and 2,4-dichlorophenol were determined. Phenols originated from night soil, municipal sewage and stream were determined at 49.15 ppm. 0.095 ppm and 0.003 ppm in average respectively. About 87 and 88 percent of phenols in sewage and night soil were biodegradated by aeration for 10 days and 74 and 51 percent of phenols in sewage and night soil by spontaneous settling for 10 days. From the tap water in Seoul during summer, 1979, chlorophenols were identified; they were average 0.042 ppb of o-chlorophenol, 0.033 ppb of 2, 6-dichlorophenol and 0.003 ppb of 2, 4-dichlorophenol respectively. With the above result and discussion, it is considered that chlorophenols should be controlled from the source as well as chlorination in water purification.

• Ocean Systems Engineering
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• 제3권3호
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• pp.181-201
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• 2013

The main objective of this work is to investigate the sloshing behavior in a baffled and unbaffled three dimensional annular-sectored water pool (i.e., tank) which is located at dome region of the primary containment. Initially two case studies were performed for validation. In these case studies, the theoretical and experimental results were compared with numerical results and good agreement was found. After the validation of present numerical procedure, an annular-sectored water pool has been taken for numerical investigation. One sector is taken for analysis from the eight sectored water pool. The free surface is captured by Volume of Fluid (VOF) technique and the fluid portion is solved by finite volume method while the structure portions are solved by finite element approach. Baffled and un-baffled cases were compared to show the reduction in wave height under excitation. The complex mechanical interaction between the fluid and pool wall deformation is simulated using a partitioned strong fluid-structure coupling.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 1998년도 추계 학술대회논문집
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• pp.167-174
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• 1998

The numerical methodology for simulating water entry behaviors of the high-speed bodies has been developed. Since the present method assumed the impact occurs within a very short time interval, the viscous effects do not have enough time to play a significant role in the impact forces, that is, the flow around a water-entry object was assumed as an incompressible potential flow and is solved by the source panel method. The elements fully submerged into the water are routinely teated, but the elements intersected by the effective planar free surface are redefined and reorganized to be amenable to the source panel method. To validate the present code, it has been applied to the ogive model and compared with experimental data. Good agreement has been obtained. The water entry behavior of the bouncing phenomena from the free surface has been also simulated using the impact forces and two degree of freedom dynamic equation. Physically, acceptable results have been obtained.