• 한국물환경학회지
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• 제25권2호
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• pp.181-192
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• 2009

In this study, the hydrological properties of permeable pavement were analyzed by the experiment and the numerical simulation. The numerical model used was a modified SWMM especially for considering the hydrological response of permeable pavement. The parameters of modified SWMM were revised by the experimental results, and then the practicability was evaluated through the comparison of the experimental and numerical simulation results. In the experiments, three different rainfall intensities such as 65 mm/hr, 90 mm/hr, 95 mm/hr were supplied for 4 hrs, and the hydraulic properties including surface outflow, subsurface outflow, ground water level, soil water contents were measured for 10 hrs. The results showed rainfall intensity effected directly on surface outflow volume and subsurface outflow volume was more effected by ground water level than rainfall intensity. The ground water level and the soil water contents were under estimated as compared with the experimental data except the portion of occurring direct runoff. The surface and subsurface outflow discharge were simulated very well in comparison with the experimental data. Consequently, the modified SWMM could be used very effectively to evaluate the hydrological property of permeable pavement.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 춘계학술발표회논문집(2)
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• pp.368-373
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• 1996

A simple set of the transition criterion of the condensation regimes and the heat transfer coefficients on the direct contact condensation of the core makeup tank is developed, and implemented in RELAP5/MOD3.1 The condensation regimes are divided into two regimes: supply limit and condensation limit. In mode]ing the transition criterion between two regimes, a large-eddy model developed by Theofanous is used, and the empirical coefficient of the present large-eddy model is close to that of the large-eddy model. It turns out that the modified code better predicts the experimental data, especially the injection flow rate and the water level trend than the original code does.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1995년도 가을 학술발표회 논문집
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• pp.258-265
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• 1995

For design of seismic isolated system the determination of isolated frequency is very important. In this paper the effects of seismic isolated frequency for cylindrical tank are investigated using the 1940 EL Centre earthquake(NS). From the results of analysis the seismic isolated frequencies significantly depend on input acceleration and displacement components in lower frequency regions. Therefore, the seismic isolated frequency should be determined by consideration of input ground motion characteristics. For the seismic analysis the modified hysteretic hi-linear model of seismic isolators which can consider the yield load variation, shape of hysterisis loop variation and hardening effects of isolators is proposed. The analyses using the proposed model give similar displacement responses but higher maximum acceleration responses than those using the simple hysteretic hi-linear model.

• 비파괴검사학회지
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• 제26권1호
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• pp.1-6
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• 2006

폐수처리시설의 응집조를 대상으로 0.392MeV의 감마선을 방출하는 In-113m을 추적자로 이용하여 체류시간분포(RTD; residence time distribution)를 측정하였다. 계측 결과는 CFSTR (constant flow stirred tank reactor) 모델을 바탕으로 구축한 K-RTD 프로그램을 이용하여 수학적으로 분석하였으며, 이를 바탕으로 혼합 특성을 규명하고자 하였다 모델에 의한 시뮬레이션 결과를 계측결과와 맞추는 과정에서 유체 거동의 특성을 표현하는 인자들을 계산하였으며, 이들 인자에 의한 시뮬레이션 결과는 실험결과에 매우 성공적으로 부합하였다. 또한 향후 본 실험에서 관찰된 bypass flow의 성분을 이론적 모델에 포함시키고 이를 분석하며 혼합조의 효율에 영향을 미치는 요소들에 대한 추가 연구의 필요성을 확인하였다.

• 환경영향평가
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• 제19권3호
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• pp.215-222
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• 2010

This research aims to gain the result of assessment of inflow categorized by runoff path using DIROM (Daily Irrigation Reservoir Operation Model) for Baengnyeong-myeon reservior which was built for residents of Baengnyeong island to solve the shortage of drinking water and stable supply of domestic water. The simulation results of DIROM and actual hydrograph of the reservoir show very low correlation with geological characteristics. The simulation results by DIROM after adjusting with modified Tank III model which considers all outflow from Tank II model as interflow among 3 level tanks show good correlation of its regional runoff and inflow characteristics with $R^2$=0.9058. In the study area, diffluence of 37% of rain fall of the study year has been simulated, which shows low result compared to the average river runoff of national water resource. In addition, 34.5% of total inflow to the study reservoir is mainly interflow and baseflow among expected several channels.

• 한국해양공학회지
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• 제24권5호
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• pp.31-38
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• 2010

The Floating storage and re-gasification unit (FSRU), which has large cargo storage tanks, is a floating liquefied natural gas (LNG) import terminal. The sloshing motion in tanks that are partially filled with LNG can cause impact pressure on the containment system and affect the global motion of the FSRU. Therefore, the accurate prediction of sloshing motion has been a significant issue in the offshore gas production industry. In this paper, a particle method based on the moving particle semi-implicit (MPS) method proposed by Koshizuka and Oka (1996) has been modified to predict sloshing motion accurately in a rectangular tank with the filling ratio of water. The simulation results, including the violent sloshing of the fluid, were validated by comparison with the original MPS method.

• 대한조선학회논문집
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• 제33권4호
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• pp.15-21
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• 1996

서울대학교 공과대학이 보유하고 있는 선형시험수조의 모형선 예인 전차를 개인용 전산기에서 온라인으로 제어 할 수 있도록 속도제어 시스템을 개량한 바 있다. 이 시스템을 활용하여 전차의 속도의 정밀한 제어가 가능하게 되었다. 이를 활용하여 선형시험수조내에 존재하게 되는 잔류 및 정재파와 같은 현상으로 인하여 모형선의 대수속도가 전차의 예인을 위하여 설정한 속도와 미소한 차이를 가지게 되는 것으로 가상하여 전차의 운전속도를 조정하고 모형선을 예인하여 저항성능에 미치는 차이를 실험적으로 확인하고자 하였다.

• 한국농공학회지
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• 제35권2호
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• pp.23-32
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• 1993

This paper describes the background and the development of a hydrologic network flow model. The model was development to simulate daily water demand and supply for selected stream reaches within a watershed, and used as a tool for evaluating, simulating, and planning a water resources system. The proposed network flow model considers daily runoff from subareas, various water demands, and diversion structures within each subarea. Daily streamflow at a reach is simulated after balancing the water demands from subareas. The lateral inflow from subareas is simulated using a modified tank model. Total water demands consist of the daily demands for agricultural, domestic, industrial, livestock, fishery, and environmental uses within a rural district. The return flow, diversions from sources and storage components such as reservoirs were also incorporated into the mode l . The developed model is a generalized version that may be applied to different combinations of river reaches for a given system. This may help potential users identify areas where water supply does not suffice the demands for different time horizons.

• 대한환경공학회지
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• 제32권9호
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• pp.830-839
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• 2010

본 연구에서는 현재 시행되고 있는 오염총량관리제 모니터링 시스템에 적용가능한 부하량 추정기법에 대하여 제시하였다. 수정 TANK 모형을 통하여 8일 간격 유량자료의 1일 간격 유량자료로의 확장을 시행하여 유황곡선의 작성을 가능하게 하였다. 7변수 대수 선형 모형 적용 통한 BOD, COD 및 TOC 부하량 추정에서 만족스러운 결과를 확인할 수 있었다. 연구의 적용의 일환으로, 낙동강유역의 BOD, COD 및 TOC 항목의 부하량 유황 곡선을 작성하여 전체적인 분포를 살펴보았다. 본 연구를 통하여 파악된 부하량 유황곡선은 해당 지점의 현재 전체적인 수질현황을 확률적으로 파악할 수 있음과 동시에 이를 시각적으로 도시할 수 있는 장점을 가지고 있다.

• 한국농공학회논문집
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• 제46권2호
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• pp.15-25
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• 2004

For the effective operation of irrigation reservoirs, a general and systematic policy is suggested to make balance of the conflicting purposes between water conservation and flood control. In this study, the flood effective analysis system was developed through the integration of long-term water budget analysis model, GIS-based HEC-HMS model and HEC-RAS model. The system structure consists of long-term water budget model using modified TANK theory, flood runoff and flood effects analysis model using HEC-GeoHMS, HEC-HMS and HEC-RAS models. The flood effects analysis system simulated the flood runoff from the upstream, downstream flood and long-term runoff of the watershed using the observed data collected from 1998 to 2002 of Seongju dam. The simulated results were reasonably good compared with the observed data. The optimal management method of the reservoir during the whole season is suggested in this study, and the flood analysis system can be a useful tool to evaluate a reservoir operation quantitatively for the mitigation of flood damages of reservoir basin.