• 상하수도학회지
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• 제27권4호
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• pp.413-428
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• 2013

In this study, Ant Colony Algorithm(ACO) was used for optimal model. ACO which are metaheuristic algorithm for combinatorial optimization problem are inspired by the fact that ants are able to find the shortest route between their nest and food source. For applying the model to water distribution systems, pipes, tanks(reservoirs), pump construction and pump operation cost were considered as object function and pressure at each node and reservoir level were considered as constraints. Modified model from Ostfeld and Tubaltzev(2008) was verified by applying 2-Looped, Hanoi and Ostfeld's networks. And sensitivity analysis about ant number, number of ants in a best group and pheromone decrease rate was accomplished. After the verification, it was applied to real water network from S water treatment plant. As a result of the analysis, in the Two-looped network, the best design cost was found to $419,000 and in the Hanoi network, the best design cost was calculated to $6,164,384, and in the Ostfeld's network, the best design cost was found to $3,525,096. These are almost equal or better result compared with previous researches. Last, the cost of optimal design for real network, was found for 66 billion dollar that is 8.8 % lower than before. In addition, optimal diameter for aged pipes was found in this study and the 5 of 8 aged pipes were changed the diameter. Through this result, pipe construction cost reduction was found to 11 percent lower than before. And to conclusion, The least cost design model on water distribution system was developed and verified successfully in this study and it will be very useful not only optimal pipe change plan but optimization plan for whole water distribution system.

• 한국물환경학회지
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• 제24권5호
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• pp.581-591
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• 2008

Most of our rivers are fragmented by the presence of at least one large dam. Dams are often the most substantial controller of the flow regimes and aquatic environments of natural river system. The quality of downstream water released from a stratified reservoir is highly dependent on upstream reservoir water quality. Thus, an integrated modeling approach is more efficient, compared to fragmented modeling approach, and necessary to better interpret the impact of dam operation on the down stream water quality. The objectives of this study were to develop an integrated reservoir-river modeling system for Daecheong Reservoir and its downstream using a two-dimensional laterally averaged hydrodynamic and water quality model, and evaluate the model's performance against field measurement data. The integrated model was calibrated and verified using filed data obtained in 2004 and 2006. The model showed satisfactory performance in predicting temporal variations of water stage, temperature, and suspended solid concentration. In addition, the reservoir-river model showed efficient computation time as it took only 3 hours for one year simulation using personal computer (1.88 Ghz, 1.00 GB RAM). The suggested modeling system can be effectively used for assisting integrated management of reservoir and river water quality.

• 한국수자원학회논문집
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• 제44권6호
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• pp.477-486
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• 2011

본 연구는 인공수로 또는 인공호수와 같은 환경 친화적 친수공간이 건설됨에 따라 발생되는 수질오염 문제를 수질모형실험을 통해 해소할 수 있는 방법을 연구하였다. 호소수의 개념으로 도입되는 인공수로 및 호수는 제한된 수량 공급으로 인해 수질악화, 악취발생 및 녹조 현상이 일어날 수 있다. 하지만, 이러한 현상을 예상할 수 있는 방법은 수치해석으로만 의지해 왔고 물리적 해석에 의한 검증이 이뤄지지 않아 실제 적용에 대한 어려움이 있었다. 따라서 본 연구에서는 오염된 물과 오염되지 않은 물이 서로 희석되어 영양염류의 농도를 낮추는 현상에 착안하여 원형과 모형의 상사에 영향을 받지 않는 무차원의 물리적 수질모형실험을 실시하였다. 또한 수체 내에서 흐름을 인공적으로 발생시키는 흐름유발기기의 효과 검증과 적용방법을 연구하여 목표수질을 유지할 수 있는 방안을 제시하였다.

• 한국물환경학회지
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• 제27권4호
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• pp.445-460
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• 2011

The objective of this study was to construct and assess the applicability of the EFDC model for Saemangeum Reservoir as a 3D hydrodynamic and water quality modeling tool that is necessary for the effective management of water quality and establishment of conservation measures. The model grids for both reservoir system only and reservoir-ocean system were created using the most recent survey data to compare the effects of different downstream boundary conditions. The model was applied for the simulations of temperature, salinity, water quality variables including chemical oxygen demand (COD), chlorophyll-a (Chl-a), phosphorus and nitrogen species and algal biomass, and validated using the field data obtained in 2008. Although the model reasonably represented the temporal and spatial variations of the state variables in the reservoir with limited boundary forcing data, the salinity level was underestimated in the middle and upstream of the reservoir when the flow data were used at downstream boundaries; Sinsi and Garyuk Gates. In turn, the error caused to increase the bias of water quality simulations, and inaccurate simulation of density flow regime of river inflow during flood events. It is likely because of the loss of momentum of sea water intrusion at downstream boundaries. In contrast to flow boundary conditions, the mixing between sea water and freshwater was well reproduced when open water boundary condition was applied. Thus, it is required to improve the downstream boundary conditions that can accommodate the real operations of the sluice gates.

• Water Engineering Research
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• 제3권2호
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• pp.143-153
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• 2002

As the natural flows in rivers dramatically decrease during drought season in Korea, a deterioration of river water quality is accelerated. Thus, consideration of downstream water quality responding to changes in reservoir release is essential for an integrated watershed management with regards to water quantity and quality. In this study, water quality models based on artificial neural networks (ANNs) method were developed using historical downstream water quality (rm $\NH_3$-N) data obtained from a water treatment plant in Geum river and reservoir release data from Daechung dam. A nonlinear multiple regression model was developed and compared with the ANN models. In the models, the rm NH$_3$-N concentration for next time step is dependent on dam outflow, river water quality data such as pH, alkalinity, temperature, and rm $\NH_3$-N of previous time step. The model parameters were estimated using monthly data from Jan. 1993 to Dec. 1998, then another set of monthly data between Jan. 1999 and Dec. 2000 were used for verification. The predictive performance of the models was evaluated by comparing the statistical characteristics of predicted data with those of observed data. According to the results, the ANN models showed a better performance than the regression model in the applied cases.

• 한국물환경학회지
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• 제25권6호
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• pp.910-915
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• 2009

The ecohydrologic characteristics according to planting in riparian zone for the riparian restoration are analyzed in this research. The ecohydrologic components due to land use change in riparian zone from existing land cover to planted area such as pasture and wildrye are simulated in the test basin with the integrated SWAT-MODFLOW model. After analysis of change of the hydrologic properties such as surface flow, lateral flow, transpiration and soil water in riparian zone, it is revealed that soil water is one of the key factors and planting of wildrye can increase soil water in riparian zone. The simulation performance of the SWAT-MODFLOW model is validated in this study and it is expected that this model can be used to evaluate various riparian restoration scenarios.

• International Journal of Computer Science & Network Security
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• 제24권4호
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• pp.147-154
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• 2024

The continuous increase in urban population due to migration of mases from rural areas to big cities has set urban water supply under serious stress. Urban water resources face scarcity of available water quantity, which ultimately effects the water supply. It is high time to address this challenging problem by taking appropriate measures for the improvement of water utility services linked with better understanding of demand side management (DSM), which leads to an effective state of water supply governance. We propose a dynamic framework for preventive DSM that results in optimization of water resource management. This paper uses Agent Based Modeling (ABM) with Digital Twin (DT) to model water consumption behavior of a population and consequently forecast water demand. DT creates a digital clone of the system using physical model, sensors, and data analytics to integrate multi-physical quantities. By doing so, the proposed model replicates the physical settings to perform the remote monitoring and controlling jobs on the digital format, whilst offering support in decision making to the relevant authorities.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2008년도 학술발표회 논문집
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• pp.500-504
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• 2008

The objective of this paper is to evaluate the feasibility of using an optimization model as a effective way to search conjunctive operation scheme to meet two conditions; one is to minimize the electric cost for pumping and another is to meet the water demand for satisfying customers. The feasibility is confirmed as comparing the best combinations of pumps between multi-regional water supply networks from multiple sources which are obtained through an optimization modeling and EPAnet modeling. KModsim model, a network optimization model, was used to determine conjunctive operation scheme in the pipe system. KModsim, based on Lagrangian Relaxation algorithm, is useful for modeling network system and obtaining simultaneously pump combination and water allocation with given input option such as energy unit cost supplying from a source into a consumer, operating pumping combination. This study develops the procedure of determining optimal conjunctive operation scheme with using KModsim model. As a study region, the water supplying systems of the Geojae-city in the Geongsang Namdo Province was selected and investigated. The EPAnet hydraulic simulation result(Ryu et al, 2007, KSWW) gave input data for optimization model; energy unit price(won/$m^3$), water service available area etc.. It was assured that the combination of pump operation through optimum conjunctive operation is to be optimum scheme to obtain the best economic water allocation with comparison to the hydraulic simulation result such as electric cost and pump combination cases. The results obtained through the study are as follows. First, It was found that a well-allocated water supply scheme, the best combination of pump operation through optimum joint operation, promises to save the electric cost and satisfy all operational goals such as stability and revenues during the period. Second, an application of KModSim, a network model, gave the amount of water allocation from each source to a consumer with consideration of economic supply. Finally, in a service area available to supply through conjunctive operation of existing inter-regional water supply networks within short distance, a conjunctive operation is useful for determining each transmission pipeline's service area and maximizing the effectiveness of optimizations in pumping operation time.

• 한국수자원학회논문집
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• 제38권11호
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• pp.937-946
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• 2005

본 연구에서는 저수지의 용수수요 증가에 따른 용수공급능력 평가를 실시하여 추가 공급 가능량과 이를 위한 저수지 운영방법을 제안하였다. 이를 위하여 전역 최적해를 탐색하는 SCE-UA법과 다중 목적함수를 적용한 최적화 모형과 저수지의 유입량, 수요량, 발전량을 추정하는 저수지 운영 모형을 결합한 저수지 최적운영 모형을 개발하였다. 개발된 모형의 적용성은 섬진강댐의 최적운영에 모형을 적용하여 평가하였다. 모형의 적용기간은 유입량을 고려하여 풍수기, 평수기, 갈수기로 구분하였다. 풍수기에는 목표 운영수위별의 발전량이 실측발전량 보다 $-2.29{\~}14.61\%$, 갈수기에는 실측발전량 보다 $-5.94{\~}3.98\%$ 증가된 결과를 나타냈다. 평수기에는 실측발전량 보다 $-0.43{\~}6.35\%$ 증가 된 결과를 나타냈다. 섬진강댐의 하류 용수 증가에 따른 용수공급 가능량을 산정하기 위하여 댐하류 방류량을 0.17, 0.50, 0.70, 1.0, 1.5, $3.0\;m^3/sec$로 구분하여 최적 운영한 결과, 하류 방류량을 $0.70\;m^3/sec$ 이하, 목표 저수위를 194.0m 이하로 할 경우 실적 운영 결과 보다 향상된 결과를 나타냈다.

• 한국화재소방학회논문지
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• 제3권1호
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• pp.3-9
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• 1989

This paper is study that the mathemetical model of water mebrane splinklikler capacity in fire prevention block. The methmetical investigation are performed about prediction of five temperature in room and water membrane splinkler capacity by use of experimental model. The good correlation between predicted and experimental results is indication the adequacy of the mothemetical model. However. further experimental and analytical worke are needed before a more general mathemetical model can be proposed.