• Title/Summary/Keyword: storage function model

Search Result 298, Processing Time 0.03 seconds

Long term Rainfall-Runoff Modeling Using Storage Function Method (저류함수를 이용한 일단위 장기유출모의 모형 구축)

  • Sung, Young-Du;Chong, Koo-Yol;Shin, Cheol-Kyun;Park, Jin-Hyeog
    • Journal of Korea Water Resources Association
    • /
    • v.41 no.7
    • /
    • pp.737-746
    • /
    • 2008
  • The purpose of developing a rainfall-runoff and reservoir model is to provide an analysis tool for hydrological engineers in order to forecast discharge of rivers and to accomplish reservoir operations easily and accurately. In this study, based on the short-term rainfall-runoff storage function model which has gained popularity for real time flood forecast in practical water management affairs, a long-term runoff model was developed for the improvement of the calculation method of effective rainfall and percolation at the infiltration area. Annual discharge was simulated for three dam watersheds(Andong, Hapcheon, Milyang) in Nakdong River basin to analyze the accuracy of the developed model and compare it to SSARR model, which is used as the long-term runoff model in current practical water management affairs. As the result of the comparison of hydrographs, SSARR model showed relatively better results. However, it is possible for the developed model to simulate reliable long-term runoff using relatively little available data and is useful for hydrological engineers in practical affairs.

Design Flood Estimation using Historical Rainfall Events and Storage Function Model in Large River Basins (과거강우사상과 저류함수모형을 이용한 대유역 계획홍수량 추정)

  • Youn, Jong-Woo;Lee, Dong-Ryul;Ahn, Won-Sik;Rim, Hae-Wook
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.29 no.3B
    • /
    • pp.269-279
    • /
    • 2009
  • The design flood estimation in a large river basin has a lot of uncertainties in areal reduction factors, time-spatial rainfall distribution, and parameters of rainfall-runoff model. The use of historical concurrent rainfall events for estimating design flood would reduce the uncertainties. This study presents a procedure for estimating design floods using historical rainfall events and storage function model. The design rainfall and time-spatial distribution were determined through analyzing concurrent rainfall events, and the design floods were estimated using storage function model with a non-linear hydrology response. To evaluate the applicability of the procedure of this study, the estimated floods were compared to results of frequency analysis of flood data. Both floods gave very similar results. It shows the applicability of the procedure presented in this study for estimating design floods in practices.

A Study on the Introduction of Fuzzy Theory to the Adjustment of Time Variant parameter

  • Lee, Jong-Kyu;Lee, Chang-Hae
    • Korean Journal of Hydrosciences
    • /
    • v.8
    • /
    • pp.69-83
    • /
    • 1997
  • The Parameters of the storage function model (SFM) are taken as constants, while they have different values during every rainfall period and the duration of the runoff. Therefore, the results of the SFM generally show remarkably large errors. In this study, the modified storage function model (MSFM), in which the time variant parameters are introduced, is proposed to improve the SFM which is a conceptual rainfall-runoff model. The fuzzy reasoning method is applied as a real-time control one of the time variant parameters of the proposed model. The applicability of the MSFM was examined in the Bochung river, at a tributary of the Geum River, Korea. The pattern of the predicted runoff hydrograph and the peak discharge by the MSFM with fuzzy control are very similar to the measured values, compared with the results produced by the SFM.

  • PDF

Estimation of the Parameters for the Clark Model through the Rainfall-Runoff Events (강우 유출사상을 통한 Clark 모형의 매개변수 평가)

  • Ahn, Tae-Jin;Baek, Chun-Woo;Kim, Min-Hyuk;Choi, Kwang-Hoon;Kang, In-Woong
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2006.05a
    • /
    • pp.770-774
    • /
    • 2006
  • The determination of feasible design flood is the most important to control flood damage in river management. Model parameters should be calibrated using observed discharge but due to deficiency of observed data the parameters have been adopted by engineer's empirical sense. Storage coefficient in the Clark unit hydrograph method mainly affects magnitude of peak flood. This study is to estimate the storage coefficients based on the observed rainfall-runoff events at the four stage stations in the Hantan river basin. Model calibration is the process of adjusting model parameter values until model results match historical data. An objective function which is the percent difference between the observed and computed peak flows is available for measuring the goodness-of-fit between computed and observed hydrographs. By sensitivity analysis for the storage coefficient, it has been shown that the storage coefficients affect the peak flows. The Clark parameters adopted in the River Rectification Basic Plan have been estimated through an iterative process designed to produce a hydrograph with the peak flow.

  • PDF

A Study on Warranty and Quality Assurance Model for Guided Missiles Based on Storage Reliability (저장신뢰도 기반의 유도탄 품질보증모델에 대한 연구)

  • Jung, Sanghoon;Lee, Sangbok
    • Journal of Applied Reliability
    • /
    • v.17 no.2
    • /
    • pp.83-91
    • /
    • 2017
  • Purpose: The purpose of this study is to develop a quality assurance model and to determine appropriate warranty period for a guided missile using its field data. Methods: 10 years of actual firing data is collected from the defense industry company and military. Parametric maximum likelihood estimation for a reliability function is determined with the data. Results: The reliability function estimates average lifetime of the missile. That function shows a user requirement, 80% reliability (lifetime) is come up when 8 years have passed, which is longer than the estimates in the missile's development phase. Conclusion: Quality assurance warranty for a guided missile must be established with actual test data. It is necessary to update and modify the reliability prediction and the warranty period with actual field test data.

Compressive Creep Behavior of Fruits

  • Kim, M.S.;Park, J.M.
    • Proceedings of the Korean Society for Agricultural Machinery Conference
    • /
    • 1993.10a
    • /
    • pp.1329-1339
    • /
    • 1993
  • Creep tests were performed to determine the nonlinear viscoelastic properties of apples and pears with the creep experiment apparatus designed in this study. Compressive creep characteristics of fruits were tested at two kinds of storage conditions, four periods of storage and three levels of initial stress. Ten replications were made at each treatment combination. The creep behavior of the fruits could be well described by the nonlinear viscoelastic model as a function of initial stress and time. however, for each level of initial stress applied, the compressive behavior of the samples was satisfactorily represented by Burger's model. For all sample fruits, the longer the samples was stored, the higher the instantaneous elastic strain was observed, and the creep progressed at a high rate. These phenomena were even more remarkable on the fruit stored at the normal temperature storage rather than at the low temperature storage.

  • PDF

Optimal Design of Batch-Storage Network (회분식 공정-저장조 그물망 구조의 최적설계)

  • 이경범;이의수
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.4 no.6
    • /
    • pp.802-810
    • /
    • 1998
  • The purpose of this study is to find the analytic solution of determining the optimal capacity of processes and storages to meet the product demand. Recent trend to reduce product delivery time and to provide high quality product to customer requires the increasing capacity of storage facilities. However, the cost of constructing and operating storage facilities is becoming substantial because of increasing land value, environmental and safety concern. Therefore, reasonable decision making about the capacity of processes and storages is important subject for industries. The industrial solution for this subject is to use the classical economic lot sizing method, EOQ(Economic Order Quantity) model, trimmed with practical experience but the unrealistic assumption of EOQ model is not suitable for the chemical plant design with highly interlinked processes and storages. This study, a first systematic attempt for this subject, clearly overcomes the limitation of classical lot sizing method. The superstructure of the plant consists of the network of serially and/or parallelly interlinked processes and storages. A novel production and inventory analysis method, PSW(Periodic Square Wave) model, is applied. The objective function of optimization is minimizing the total cost composed of setup and inventory holding cost. The advantage of PSW model comes from the fact that the model provide a set of simple analytic solution in spite of realistic description of material flow between process and storage. The resulting simple analytic solution can greatly enhance the proper and quick investment decision for the preliminary plant design confronting diverse economic situation.

  • PDF

Calibration and Estimation of Parameter for Storage Function Model (저류함수모형의 매개변수 보정 및 추정)

  • Kim, Bum Jun;Kawk, Jae Won;Lee, Jin Hee;Kim, Hung Soo
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.28 no.1B
    • /
    • pp.21-32
    • /
    • 2008
  • Flood forecasting is a very important tool as one of nonstructural measures for reduction of flood damages in life and property and its accuracy is also an important factor. However, when we apply the Storage Function Model(SFM) which is mainly used for the flood forecasting system in Korea, the determination of the parameters is very important but it is difficult. So, the parameters have been calibrated by using an empirical formulas and judgement of hydrologist. Hence, in this study we perform the sensitivity analysis to understand the parameter characteristics and establish the ranges of parameters of the SFM. Also we do the parameter calibration by using the optimization techniques and objective functions, and evaluate their performances. Especially, we suggest a method to determine proper parameters by using a objective function which can be obtained from flood events. So, we use the suggested method for parameter estimation and compare the estimated parameters with the previously reported parameters. As a result of the application, the estimated parameters by the suggested method showed better than them from the previously reported parameters.

Optimal Design of Batch-Storage Network with Finite Intermediate Storage (저장조 용량제약이 있는 회분식 공정-저장조 그물망 구조의 최적설계)

  • Kim, Hyung-Min;Kim, Kyoo-Nyun;Lee, Gyeong-Beom
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.7 no.10
    • /
    • pp.867-873
    • /
    • 2001
  • The purpose of this study is to find analytic solution of determining the optimal capacity (lot-size) of multiproduct acyclic multistage production and inventory system to meet the finished product demand under the constraint of finite intermediate storage. Intermediate storage is a practical way to mitigate the material flow imbalance through the line of supply and demand chain. However, the cost of constructing and operating storage facilities is becoming substantial because of increasing land value, environmental and safety concern. Therefore, reasonable decision-making about the capacity of processes and storage units is an important subject for industries. The industrial solution for this subject is to use the classical economic lot sizing method, EOQ/EPQ(Economic Order Quantity/Economic Production Quantity) model, incorporated with practical experience. But EOQ/EPQ model is not suitable for the chemical plant design with highly interlinked processes and storage units because it is developed based on single product and single stage. This study overcomes the limitation of the classical lot sizing method. The superstructure of the plant consists of the network of serially and/or parallelly interlinked non-continuous processes and storage units. The processes transform a set of feedstock materials into another set of products with constant conversion factors. A novel production and inventory analysis method, PSW(Periodic Square Wave) model, is applied to describe the detail material flows among equipments. The objective function of this study is minimizing the total cost composed of setup and inventory holding cost. The advantage of PSW model comes from the fact that the model provides a set of simple analytic solutions in spite of realistic description of the material flows between processes and storage units. the resulting simple analytic solution can greatly enhance the proper and quick investment decision for the preliminary plant design problem confronted with economic situation.

  • PDF

Stochastic Continuous Storage Function Model with Ensemble Kalman Filtering (II) : Application and Verification (앙상블 칼만필터를 연계한 추계학적 연속형 저류함수모형 (II) : - 적용 및 검증 -)

  • Lee, Byong-Ju;Bae, Deg-Hyo;Shamir, Eylon
    • Journal of Korea Water Resources Association
    • /
    • v.42 no.11
    • /
    • pp.963-972
    • /
    • 2009
  • The objective of this study is to evaluate an application of stochastic continuous storage function model with ensemble Kalman filter technique. The case study is performed at the upstream basin of Jibo streamflow gauge including Andong and Imha dam. Test period is for the rainy season during 2006 and 2007. Long term runoff analysis is feasible in the case of using deterministic model. Ensemble members for input data and parameters are generated using Monte Carlo simulation for the purpose of applying ensemble Kalman filter technique. The cumulative absolute errors of stochastic model to the deterministic one are improved for the amount of 17.5 %, 18.3 % and more than 40.0 % for Andong dam, Imha dam and Jibo station, respectively. The results indicate that the stochastic model improves the accuracy of the simulated discharge considerably.