Stochastic multiobjective optimization of reservoirs in parallel     

Y. C. Wang  J. Yoshitani  K. Fukami 《水文研究》2005,19(18):3551-3567

A stochastic multiobjective optimization method for finding noninferior solutions of the operation problem of reservoirs in parallel is presented. This problem is characterized by a multiobjective optimization, a multireservoir system, and stochasticity of inflows, which represent three difficult aspects in reservoir system planning and operation. In this method, a constraint technique, decomposition iteration, and simulation analysis are employed conjunctively to deal with the three difficult aspects. The constraint technique is intended to transform the multiobjective optimization into a uniobjective one and the decomposition iteration in conjunction with the simulation analysis attempts to alleviate the dimensionality problem. The proposed methodology is applied to a reservoir system in the upper Tone River basin, which consists of three reservoirs in parallel and is operated primarily for three objectives: hydropower, water supply, and flood control. A total of 49 noninferior solutions for the reservoir system are obtained, from which the decision makers may be able to find the most satisfactory operating policy. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

Upper bound limit analysis using simplex strain elements and second‐order cone programming     

A. Makrodimopoulos  C. M. Martin 《国际地质力学数值与分析法杂志》2007,31(6):835-865

In geomechanics, limit analysis provides a useful method for assessing the capacity of structures such as footings and retaining walls, and the stability of slopes and excavations. This paper presents a finite element implementation of the kinematic (or upper bound) theorem that is novel in two main respects. First, it is shown that conventional linear strain elements (6‐node triangle, 10‐node tetrahedron) are suitable for obtaining strict upper bounds even in the case of cohesive‐frictional materials, provided that the element sides are straight (or the faces planar) such that the strain field varies as a simplex. This is important because until now, the only way to obtain rigorous upper bounds has been to use constant strain elements combined with a discontinuous displacement field. It is well known (and confirmed here) that the accuracy of the latter approach is highly dependent on the alignment of the discontinuities, such that it can perform poorly if an unstructured mesh is employed. Second, the optimization of the displacement field is formulated as a standard second‐order cone programming (SOCP) problem. Using a state‐of‐the‐art SOCP code developed by researchers in mathematical programming, very large example problems are solved with outstanding speed. The examples concern plane strain and the Mohr–Coulomb criterion, but the same approach can be used in 3D with the Drucker–Prager criterion, and can readily be extended to other yield criteria having a similar conic quadratic form. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

Hydrological modelling of Ethiopian catchments using limited data     

Muluneh A. Mekonnen  Anders Wörman  Bijan Dargahi  Admasu Gebeyehu 《水文研究》2009,23(23):3401-3408

The hydrological component of the soil and water assessment tool (SWAT) model is adapted for two Ethiopian catchments based on primary knowledge of the coherence spectrum between rainfall and stream flow data. Spectrum analysis using the available nearby climatic data is made to limit the temporal and spatial scales (inverse rate coefficients) subject to the calibration of compartmentalized runoff models. The exclusion of unwarranted time scales in the calibration implies that the model efficiency (r² values) decrease only moderately between calibration and validation, and the optimization is focused on warranted problems. On the basis of the available data for the two Ethiopian catchments, the implication is that only periods longer than about 50 days can be reliably evaluated in the model. The model structure of SWAT for the surface runoff and groundwater flow response is modified to make the time scales consistent with the results of the spectrum analysis. An optimization algorithm is developed to constrain and combine the model parameters with the spectrum analysis results. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

阳极焙烧炉结构优化设计     

姚成军  徐明厚 《广东海洋大学学报》2004,24(3):47-51

对以重油作为燃料的阳极焙烧炉的火道结构进行了优化模拟计算。从炉子的设计角度提出了解决炉内流动场、温度分布不均匀的方案。分析了两种结构优化方案的可行性 ,并得出综合优化方案。适当的调整挡板的位置可以改善气流的分布。结果显示 ,综合优化方案对改善阳极焙烧炉的燃烧条件有着显著效果。数值模拟的方法为阳极焙烧炉结构和运行参数的优化提供了较准确、快速和经济的研究手段。  相似文献   

黑河水库单薄山梁排水洞方案优选研究     

王玮 《地球科学与环境学报》2002,24(4):30-34

黑河水库是解决西安市城市供水、农田灌溉及水力发电的大型水利水电工程。其左岸的单薄山梁既构成大坝坝肩岩体,蓄水后又成为一天然坝体。水库蓄水后的渗漏及渗透稳定性决定了水库能否安全高效的运行。黑河工程指挥部在防渗灌浆帷幕施工后,提出在帷幕下游增设单排排水洞。就此对排水洞方案进行了优选研究。  相似文献   

SOIL SPATIAL ANALYSIS AND AGRICULTURAL LAND USE OPTIMIZATION BY USING GIS     

GAOJun-feng LIChang-feng ZHANGHong-hui 《中国地理科学(英文版)》2003,13(1):25-29

This paper discusses the methods and process of Geographic Information System(GIS) applied in soil spatial analysis ,involving the collection of soil spatial data that GIS required ,spatial analysis method of soil nutrient,land use,slope and exposure of geography,crop yield and other factors,and also including acquiring soil spatial information and creating thematic map,and so on .Taking Hengjing Town in Wuxian County of Jiangsu Province as a case study and the maximum income as a principle,and applying the GIS methods and their interrelated models,we have calculated the most optimized agricultural land and the possible maximum income of Hengjing Town.According to the method,we can rationally regulate local agricultural production,and put forward some scenarios for optimizing agricultural structure of Hengjing Town .The paper puts forward an evaluation method of land adaptability based on soil spatial analysis,and offers some research clews to optimize agricultural land use constitutions.so the paper will be have important reference value for soil study.  相似文献   

A linear road object matching method for conflation based on optimization and logistic regression   总被引：1，自引：0，他引：1  

Xiaohua Tong  Dan Liang  Yanmin Jin 《International journal of geographical information science》2014,28(4):824-846

The purpose of object matching in conflation is to identify corresponding objects in different data sets that represent the same real-world entity. This article presents an improved linear object matching approach, named the optimization and iterative logistic regression matching (OILRM) method, which combines the optimization model and logistic regression model to obtain a better matching result by detecting incorrect matches and missed matches that are included in the result obtained from the optimization (Opt) method for object matching in conflation. The implementation of the proposed OILRM method was demonstrated in a comprehensive case study of Shanghai, China. The experimental results showed the following. (1) The Opt method can determine most of the optimal one-to-one matching pairs under the condition of minimizing the total distance of all matching pairs without setting empirical thresholds. However, the matching accuracy and recall need to be further improved. (2) The proposed OILRM method can detect incorrect matches and missed matches and resolve the issues of one-to-many and many-to-many matching relationships with a higher matching recall. (3) In the case where the source data sets become more complicated, the matching accuracy and recall based on the proposed OILRM method are much better than those based on the Opt method.  相似文献   

THE VARIABILITY CHARACTERISTICS AND PREDICTION OF GUANGDONG POWER LOAD DURING 2002 - 2004     

罗森波  纪忠萍  马煜华  骆晓明  曾沁  林少冰 《热带气象学报(英文版)》2007,13(2):153-156

The variability characteristics of Guangdong daily power load from 2002 to 2004 and its connection to meteorological variables are analyzed with wavelet analysis and correlation analysis.Prediction equations are established using optimization subset regression. The results show that a linear increasing trend is very significant and seasonal change is obvious. The power load exhibits significant quasi-weekly (5 - 7 days) oscillation, quasi-by-weekly (10 - 20 days) oscillation and intraseasonal (30 - 60 days) oscillation. These oscillations are caused by atmospheric low frequency oscillation and public holidays. The variation of Guangdong daily power load is obviously in decrease on Sundays, shaping like a funnel during Chinese New Year in particular. The minimum is found at the first and second day and the power load gradually increases to normal level after the third day during the long vacation of Labor Day and National Day. Guangdong power load is the most sensitive to temperature, which is the main affecting factor, as in other areas in China. The power load also has relationship with other meteorological elements to some extent during different seasons. The maximum of power load in summer, minimum during Chinese New Year and variation during Labor Day and National Day are well fitted and predicted using the equation established by optimization subset regression and accounting for the effect of workdays and holidays.  相似文献   

Advantages of the analytic element method for the solution of groundwater management problems   总被引：1，自引：0，他引：1  

Shishir Gaur  Djamel Mimoun  Didier Graillot 《水文研究》2011,25(22):3426-3436

In the simulation‐optimization approach, a coupled optimization and groundwater flow/transport model is used to solve groundwater management problems. The efficiency of the numerical method, which is used to simulate the groundwater flow, is one the major reason to obtain the best solution for a management problem. This study was carried out to examine the advantages of the analytic element method (AEM) in the simulation‐optimization approach, for the solution of groundwater management problems. For this study, the AEM and finite difference method (FDM) based flow models were developed and coupled with the particle swarm optimization (PSO)‐based optimization model. Furthermore, the AEM‐PSO and FDM‐PSO models developed were applied in hypothetical as well as real field conditions to address groundwater management problems and the results were compared. For the real field situation, the models developed were applied to the Dore River basin in France to minimize the installation and operational cost of new pumping wells taking the location and discharge of the pumping wells as decision variables. The constraints of the problem were identified with the help of stakeholders and water authority officials. The AEM flow model was developed to facilitate the management model particularly when at each iteration, the optimization model calls for a simulation model to calculate the values of groundwater heads. The results show that, at some points, the AEM‐PSO model is efficient in identifying the optimal location of wells and consequently results in optimal costs, sometimes difficult when using the FDM. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Dual state-parameter estimation of root zone soil moisture by optimal parameter estimation and extended Kalman filter data assimilation   总被引：1，自引：0，他引：1  

Haishen Lü  Zhongbo Yu  Yonghua ZhuSam Drake  Zhenchun HaoEdward A. Sudicky 《Advances in water resources》2011,34(3):395-406

With well-determined hydraulic parameters in a hydrologic model, a traditional data assimilation method (such as the Kalman filter and its extensions) can be used to retrieve root zone soil moisture under uncertain initial state variables (e.g., initial soil moisture content) and good simulated results can be achieved. However, when the key soil hydraulic parameters are incorrect, the error is non-Gaussian, as the Kalman filter will produce a persistent bias in its predictions. In this paper, we propose a method coupling optimal parameters and extended Kalman filter data assimilation (OP-EKF) by combining optimal parameter estimation, the extended Kalman filter (EKF) assimilation method, a particle swarm optimization (PSO) algorithm, and Richards’ equation. We examine the accuracy of estimating root zone soil moisture through the optimal parameters and extended Kalman filter data assimilation method by using observed in situ data at the Meiling experimental station, China. Results indicate that merely using EKF for assimilating surface soil moisture content to obtain soil moisture content in the root zone will produce a persistent bias between simulated and observed values. Using the OP-EKF assimilation method, estimates were clearly improved. If the soil profile is heterogeneous, soil moisture retrieval is accurate in the 0-50 cm soil profile and is inaccurate at 100 cm depth. Results indicate that the method is useful for retrieving root zone soil moisture over large areas and long timescales even when available soil moisture data are limited to the surface layer, and soil moisture content are uncertain and soil hydraulic parameters are incorrect.  相似文献