水库群防洪调度的逐次优化方法   总被引：16，自引：1，他引：16       下载免费PDF全文

都金康  周广安 《水科学进展》1994,5(2):134-141

针对防洪系统的具体问题,分析了并联水库群下泄流量与河道防洪控制点洪峰流量之间的内在联系,根据“先泄、后蓄、再分洪”的一般洪水调度原则,提出了水库群拱水调度模型及其逐次优化解法。该方法成功地实现了水库群之间以及水库群与区间汇流的错峰,为洪水实时调度及防洪系统规划提供了一套简捷、高效而又符合实际的模型和解法。  相似文献   

卡尔曼滤波方法在天气预报中的应用   总被引：21，自引：4，他引：21  

陆如华  何于班 《气象》1994,20(9):41-43

从气象应用角度介绍了卡尔曼滤波的基本原理及其递推算法。为了说明卡尔曼滤波递推算法的应用方法，制作了北京１９９３年１月份逐日最低气温３６小时预报。预报结果令人满意，表明该方法很有实用价值，与ＭＯＳ方法相比，它的优点是不需要收集大样本历史资料，因此，它容易适应数值预报模式的变化。  相似文献   

On‐line identification of non‐linear hysteretic structural systems using a variable trace approach     

Jeng‐Wen Lin  Raimondo Betti  Andrew W. Smyth  Richard W. Longman 《地震工程与结构动力学》2001,30(9):1279-1303

In this paper, an adaptive on‐line parametric identification algorithm based on the variable trace approach is presented for the identification of non‐linear hysteretic structures. At each time step, this recursive least‐square‐based algorithm upgrades the diagonal elements of the adaptation gain matrix by comparing the values of estimated parameters between two consecutive time steps. Such an approach will enforce a smooth convergence of the parameter values, a fast tracking of the parameter changes and will remain adaptive as time progresses. The effectiveness and efficiency of the proposed algorithm is shown by considering the effects of excitation amplitude, of the measurement units, of larger sampling time interval and of measurement noise. The cases of exact‐, under‐, over‐parameterization of the structural model have been analysed. The proposed algorithm is also quite effective in identifying time‐varying structural parameters to simulate cumulative damage in structural systems. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

Assimilation of temperature and salinity using isotropic and anisotropic recursive filters in Tropic Pacific     

LIU Ye  ZHAO Yanling 《海洋学报(英文版)》2011,30(1):15-23

A data assimilation scheme used in the updated Ocean three-dimensional Variational Assimilation System (OVALS),OVALS2,is described.Based on a recursive filter (RF) to estimate the background error covariance (BEC) over a predetermined scale,this new analysis system can be implemented with anisotropic and isotropic BECs.Similarities and differences of these two BEC schemes are briefly discussed and their impacts on the model simulation are also investigated.An idealized experiment demonstrates the ability of the updated analysis system to construct different BECs.Furthermore,a set of three years experiments is implemented by assimilating expendable bathythermograph (XBT) and ARGO data into a Tropical Pacific circulation model.The TAO and WOA01 data are used to validate the assimilation results.The results show that the model simulations are substantially improved by OVALS2.The inter-comparison of isotropic and anisotropic BEC shows that the corresponding temperature and salinity produced by the anisotropic BEC are almost as good as those obtained by the isotropic one.Moreover,the result of anisotropic RF is slightly closer to WOA01 and TAO than that of isotropic RF in some special area (e.g.the cold tongue area in the Tropic Pacific).  相似文献   

Application of a Recursive Filter to a Three-Dimensional Variational Ocean Data Assimilation System     

LIU Ye  YAN Changxiang 《大气科学进展》2010,27(2):293-302

In order to improve the efficiency of the Ocean Variational Assimilation System (OVALS), which has been widely used in various applications, an improved OVALS (OVALS2) is developed based on the recursive filter (RF) algorithm. The first advantage of OVALS2 is that memory storage can be substantially reduced in practice because it implicitly computes the background error covariance matrix; the second advantage is that there is no inversion of the background error covariance by preconditioning the control var...  相似文献   

多层递阶回归分析法在全国初夏雨量预测中的应用   总被引：1，自引：0，他引：1  

陈红玉  高志伟  李建美  钟爱华 《干旱气象》2008,26(4):80-85

在传统统计方法的基础上,引入多层递阶方法。将多层递阶方法与回归方法合二为一,作为新的预测方法尝试,以弥补常规统计方法中回归系数是常数的不足。将多层递阶回归方法应用于短期气候预测,建立多层递阶回归模型,并用全国160个气象站5月份雨量作预报试验。经过近2a的实际预报表明：该模型对华中、华东、两广大部、云贵高原大部的5月份雨量有较好的预报能力,具有一定的参考价值。  相似文献   

生命线网络可靠度分析的改进最小路递推分解算法     

刘威  李杰 《地震工程与工程振动》2009,29(5)

在生命线网络最小路递推分解算法的基础上,充分利用分解过程中的信息,采用合并节点的方法,快速降低分解出来子网的复杂程度,从而达到大幅度减少分解出来的不交最小路(割)数量和提高计算效率的目的.计算实例分析表明,与最小路递推分解算法相比,改进算法能更为高效地给出网络可靠度,是一种有效的生命线工程网络抗震可靠性分析工具.  相似文献   

一种高准确度的约束Delaunay三角网生成算法研究   总被引：1，自引：0，他引：1  

宋晓眉  张晓东  李建林 《地理与地理信息科学》2009,25(1)

约束线段的嵌入是CDT两步法的关键步骤之一,目前该方面的研究还不够完善,主要忽视了影响区域是凹多边形和影响区域内包含悬挂点的情况.该文研究带有约束条件的Delaunay三角网的生成问题,考虑了约束线段影响区域的特殊情况,采用递归割耳法嵌入约束线段,先将影响区域调整为简单多边形,再递归寻找并割去多边形的耳,最终将影响区域重新三角剖分.该方法可有效提高约束DIelaunay三角网的质量.  相似文献   

辨识方法的计算效率(1):递推算法     

丁锋 《南京气象学院学报》2012,4(4):289-300

算法的计算量可用其乘法运算次数和加法运算次数表示(除法作为乘法对待,减法作为加法对待).一次乘法运算或一次加法运算称为一个flop,即一次浮点运算.作为"辨识方法的计算效率"系列3篇连载论文的第1篇,主要了讨论递推辨识算法的计算量,包括向量和矩阵基本运算的flop数,以及线性回归系统、多元线性回归系统、多变量系统的随机梯度辨识算法、最小二乘辨识算法、递推最小二乘辨识算法的最经济计算量,即实现算法的最少flop数.  相似文献   

An improved cut-based recursive decomposition algorithm for reliability analysis of networks     

Wei Liu  Jie Li 《地震工程与工程振动(英文版)》2012,11(1):1-10

In this paper,an improved cut-based recursive decomposition algorithm is proposed for lifeline networks.First,a complementary structural function is established and three theorems are presented as a pr...  相似文献