• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2009년도 학술발표회 초록집
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• pp.1612-1615
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• 2009

Water supply reliability indexes (WSRI) is estimated for assessment of water supply capacity in the downstream for parallel reservoir system in Nakdong River, South Korea, using allocation rule (AR) according to the water supply capacity of each reservoir and the characteristic of parallel reservoir system. The result of the analyzing parallel reservoir system for Andong and Imha reservoir in Nakdong River does not include evidences available enough to decide whether the results of water supply analysis are excellent in the current reliability evaluation or not. However, AR (C) shows a good result in the water supply capacity for each reservoir based on the connected operation system and the total water supply capacity at the control point of downstream by the average water supply capacity and possible range of water supply capacity suggested by this study. The average water supply capacity is analyzed by the reliability of monthly average water supply capacity. Furthermore, the possible range of water supply capacity is estimated by the standard deviation when water deficit occurs. Therefore, AR (C) is useful to establish and estimate the planning water supply capacity according to the monthly water supply condition and the possible range of water supply capacity when the water supply capacity deficit occurs, South Korea.

• 상하수도학회지
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• 제21권2호
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• pp.215-224
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• 2007

The purpose of this study was to estimates water supply reliability indices of the water supply by Allocation Rules(AR) for parallel reservoirs. Rule (A) can be considered it as only current storage, Rule(B) can be considered it as current storage and inflow and Rule(C) can be considered it as current storage, inflow and water supply capacity. First, conditions of water supply are divided by Condition I for the monthly constant water supply and Condition II for the monthly varied water supply. Second, results of allocation coefficients are revealed the smallest different at Rule(C). The analysis of water supply showed that the capability of water supply is superior to the Rule(B), it is superior to the Rule(C) on the base of the balance of water supply. The reliability analysis was highly showed at the Rule(B) and Rule(C). A methodology for the analysis of water supply was developed and applied to the parallel reservoir system from this research, The operation rule for the parallel reservoir can be slightly modified and successfully applied to the different kinds of the parallel reservoir system.

• 한국환경과학회지
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• 제15권3호
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• pp.261-269
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• 2006

In this study, an optimization technique was developed from the application of allocation rule. The results obtained from the water supply analysis and reliability indices analysis of Andong dam and Imha dam which are consist of parallel reservoir system are summarized as the followings; Allocation rule(C) is effective technique at the parallel reservoir system because results of the water supply analysis, storage analysis and reliability indices analysis is calculated reasonable results. Also, reliability indices analysis results are not sufficient occurrence based reliability or quantity based reliability. Thus reliability indices analysis are need as occurrence based reliability, quantity based reliability vulnerability, resilience, average water supply deficits and average storage. And water supply condition is better varying water supply condition than constant water supply condition.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.719-722
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• 2003

This paper presents the development of reservoir characterization model equipped with parallelized genetic algorithm, and its application for a heterogeneous reservoir system with integration of the well data and multi-phase production data. A parallel processing method performed by PC-cluster was applied to the developed model in order to reduce time for an inverse calculation. By utilizing the developed model, we performed the inverse calculation with the production data obtained from three layered reservoir system to estimate porosity and permeability distribution. As a result, the pressures observed at well almost identical to those calculated by the developed model. Also, it was confirmed that parallel processing could be applied for reservoir characterization study efficiently.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2006년도 학술발표회 논문집
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• pp.1176-1181
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• 2006

본 연구에서는 병렬구조를 가진 안동댐과 임하댐에 대하여 할당법칙(Allocation rule, AR)을 이용하여 용수공급해석과 신뢰도지표를 산정하였다. 할당계수의 분석결과로는 안동댐이 용수공급의 기여도가 임하댐과 비교해서 Rule(A), Rule(B)에서는 66%이상으로 분석되었으며, Rule(C)의 경우 거의 대등한 기여를 하는 것으로 분석되었다. Rule(C)의 경우는 안동댐과 임하댐의 각각의 저류상태와 공급능력 상태에 따라 저류량과 유입량의 합을 댐의 평균저류량으로 나눈 비에 의해 공급량이 할당되어서 우수한 결과를 나타내었다. 병렬저수지 시스템의 용수공급의 분석기준에 있어 월별로 일정한 양을 기준으로 분석하는 것보다는 월별 용수변화량을 고려한 경우가 용수공급분석에 있어 우수한 결과를 나타나는 것으로 분석되었다. 본 연구를 기초로 하여 용수공급해석을 위한 새로운 기법이 개발되어 병렬저수지에 적용되었으며, 이 운영규칙은 여러 종류의 병렬저수지 시스템의 적용에 있어 효율적인 운영방안을 수립할 수 있을 것이다.

• 상하수도학회지
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• 제19권4호
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• pp.487-496
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• 2005

Chlorine bulk decay tests were carried out by bottle test under controlled conditions in a laboratory. Experiments were performed at different temperatures: $5^{\circ}C$, $15^{\circ}C$, $25^{\circ}C$, and the water temperatures when samples were taken from the effluent just before entering to its distribution system. 38 bulk tests were performed for water of Al (water treatment plant), 4 bulk tests for A2 (large service reservoir), and A3(pumping station). Residual chlorine concentrations in the amber bottles were measured over time till about 100 hours and bulk decay coefficients were evaluated by assuming first-order, parallel first-order, second-order. and $n^{th}-order$ reaction. The $n^{th}-order$ coefficients were obtained using Fourth-order Runge-Kutta Method. A good-fit by the average coefficient of determination ($R^2$) was first-order ($R^2=0.90$) < parallel first-order ($R^2{_{fast}}=0.92$, $R^2{_{slow}}=0.95$) < second-order ($R^2=0.95$) < $n^{th}-order$ ($R^2=0.99$). But if fast reaction of parallel first-order bulk decay were applied to the effluent of large service reservoir with ca. 20 hours of travel time and slow reaction in the water distribution system following the first 20 hours, parallel first-order bulk decay would be best and easy for application of water quality modeling technique.

• 한국수자원학회논문집
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• 제36권2호
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• pp.195-209
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• 2003

본 연구에서는 낙동강 상류유역의 병렬 다목적댐군인 안동 및 임하다목적 댐의 장기간 유입량을 산정하는데 공간추계 신경망모형이 사용되었다. 공간추계 신경망모형은 역전파 알고리즘으로 LMBP와 BFGS-QNBP를 각각 사용하였다. 공간추계 신경망모형의 구조는 입력층, 은닉층 및 출력층의 3개의 층과 차례대로 8-8-2개의 노드로 구성되어 있다. 입력층 노드는 안동 및 임하다목적 댐의 월평균유입량, 월면적강우량, 월별 증발접시 증발량과 월평균기온으로 구성되어 있으며, 자료시계열은 시간적으로 차이가 있다. 공간추계 신경망모형의 훈련을 위하여 추계학적 모형중 하나인 PARMA(1,1)에 의해서 훈련자료를 모의발생시켰으며, 모의발생된 자료는 공간추계 신경망모형의 훈련에 사용되었다. 훈련을 통하여 공간추계 신경망모형의 매개변수인 최적연결강도와 편차를 산정하였다. 산정된 매개변수는 안동 및 임하다목적 댐의 실측자료를 이용하여 공간추계 신경망모형의 검증에 이용되었으며, 통계분석과 수문곡선의 비교를 통하여 우수한 결과를 나타내었다. 따라서 공간추계 신경망모형은 낙동강 상류유역의 병렬저수지군의 장기간 연계운영기법 개발을 위하여 기초적인 자료를 제공하고, 용수분배 및 관리에 도움을 줄 것이다.

• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2001년도 Proceedings of 2001 Korea-Japan Joint Seminar on Particle Image Velocimetry
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• pp.36-43
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• 2001

The flow field structures of two interacting parallel supersonic free jets are studied by flow visualization using planar laser-induced fluorescence of NO seeded in nitrogen gas. The experiments are carried out for several distances between two orifice centers and for various ratios of the pressure in the reservoir to that in the expansion chamber. The flow fields are visualized mainly on the plane including two jet centerlines and its characteristic shock system, especially a cell structure formed secondly by interaction of two jets, are analyzed. The positions of the normal shock depending on the pressure ratios are also compared.

• 대한기계학회논문집B
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• 제29권1호
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• pp.9-15
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• 2005

From the geometric parameter study, an optimal ejector design procedure of pressure recovery system for chemical lasers was acquired. For given primary flow reservoir conditions, an up-scaled ejector was designed and manufactured. In the performance test, secondary mass flow rate of 100g/s air was entrained satisfying the design secondary pressure, $40{\sim}50torr$. Performance validation of a supersonic ejector system along with an investigation of effects of supersonic diffuser was conducted. Placement of the diffuser at the secondary inlet further reduced diffuser upstream pressure to 7torr. Lastly, the duplicate of apparatus (air 500g/s secondary mass flow rate each) was built and connected in parallel to assess proportionality behavior on a system to handle larger mass flow rate. Test and comparison of the parallel unit demonstrated the secondary mass flow rate was proportional to the number of individual units that were brought together maintaining the lasing pressure.

• 한국수소및신에너지학회논문집
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• 제21권5호
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• pp.405-411
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• 2010

A 5kW class SOFC cogeneration system consisted of a hot box part, a cold BOP (balance of plant) part, and a hot water reservoir. The hot box part contained a stack, a fuel reformer, a catalytic combustor, and heat exchangers. A cold BOP part was composed of blowers, pumps, a water trap, and system control units. A 5kW stack was designed to integrate 2 sub-modules. In this paper, the 5kW class SOFC system was operated using 2 short stacks connected in parallel to test the sub-module and the system. A short stack had 15 cells with $15{\times}15 cm^2$ area. When a natural gas was used, the total power was about 1.38 kW at 120A. Because the sub-modules were connected in parallel and current was loaded using a DC load, voltages of sub-modules were same and the currents were distributed according to the resistance of sub-modules. The voltage of the first stack was 11.46 V at 61A and the voltage of the second stack was 11.49V at 59A.