基于不确定性分析框架的动态环状河网水质模型——以温州市温瑞塘河为例   总被引：6，自引：1，他引：6       下载免费PDF全文

徐一剑  曾思育  张天柱 《水科学进展》2005,16(4):574-580

以温州市温瑞塘河为背景,基于不确定性分析的框架,开发了动态环状河网水质模型。用HSY(Hornberger,Spear and Young)算法作水质参数的不确定性分析,求得模型参数的空间分布,从而提高模型使用的可靠性、降低决策的风险度。模型由水量子模型及水质子模型两部分组成:水量子模型采用圣维南方程并用四级解法求解;水质子模型采用CSTR(Continuously Stirred Tank Reactor)模型的机理,并结合环状河网特征作了修正,由于只需解常微分方程,因而避免了矩阵求解,显著提高了计算效率,使得用HSY算法进行不确定性分析成为可能。模型选取温州市温瑞塘河流域的鹿城区河网进行了首次应用,用HSY算法率定水质参数并讨论了参数的不确定性。对参数率定结果进行验证,结果比较理想。最后简要讨论了参数不确定性传递。  相似文献   

GPS静态定位技术在滆湖公路大桥测量中的应用     

方萍  赵卫  陈勇 《现代测绘》2005,28(1):29-30

介绍了利用全球定位系统(GPS)静态定位技术，如何为滆湖公路大桥建立控制网，延伸出时控制网平差方案的确立上，以及如何使控制网中的成果与公路主线控制网中的成果互相兼容，从而为工程的设计与施工提供必要的控制资料。  相似文献   

附加系统参数平差法在导线网中的应用     

刘青利隋立芬  刘雁雨 《测绘科学与工程》2005,25(3):21-25

本文探讨了附加系统参数平差法在带有测距系统误差的导线网中的应用，说明了当系统误差比较显著时．采用附加系统参数平差法的可行性、必要性及其优越性。  相似文献   

Hyper Redundancy for Accuracy Enhancement in Automated Close Range Photogrammetry   总被引：1，自引：0，他引：1  

Clive S.  Fraser  Alex  Woods  Danny  Brizzi 《The Photogrammetric Record》2005,20(111):205-217

A generic network design in close range photogrammetry is one where optimal multi-ray intersection geometry is obtained with as few camera stations as practicable. Hyper redundancy is a concept whereby, once the generic network is in place, many additional images are recorded, with the beneficial impact upon object point precision being equivalent to the presence of multiple exposures at each camera position within the generic network. The effective number of images per station within a hyper redundant network might well be in the range of 10 to 20 or more. As is apparent when it is considered that a hyper redundant network may comprise hundreds of images, the concept is only applicable in practice to fully automatic vision metrology systems, where it proves to be a very effective means of enhancing measurement accuracy at the cost of minimal additional work in the image recording phase. This paper briefly reviews the network design and accuracy aspects of hyper redundancy and illustrates the technique by way of the photogrammetric measurement of surface deformation of a radio telescope of 26 m diameter. This project required an object point measurement accuracy of σ  = 0·065 mm, or 1/400 000 of the diameter of the reflector.  相似文献   

对江西农经网如何更好地提供信息服务的探讨     

路名芬  付永民 《气象与减灾研究》2002,25(4):33-35

分析了江西农村经济信息网(www.jxagriec.gov.cn)的现状,指出农经网信息服务正面临着挑战,并在此基础上阐述了农经网信息服务的发展思路。  相似文献   

广西新一代"区-地-县"三级气象信息网络系统     

李宇中 《气象研究与应用》2002,23(3):33-36

介绍广西新一代“区 -地 -县”三级气象信息网络系统在拓扑结构、业务软件和运行管理等方面的基本情况 ,总结了建设、运行管理过程中成功经验以及存在的问题 ,指出 :充分利用现有通讯网络资源 ,强化业务软件的开发应用 ,提高网络传输监控管理水平 ,是经济欠发达地区扩展气象信息网络业务能力的重要途径  相似文献   

基于气象因子的华中电网负荷预测方法研究   总被引：7，自引：0，他引：7       下载免费PDF全文

胡江林  洪斌等 《应用气象学报》2002,13(5):600-608

在分析各种节假日负荷变化规律的基础上, 利用气象因子作预报变量, 使用动态的综合线性回归和自回归相结合的混合线性回归方法及非线性的人工神经网络方法来进行华中电网日负荷和日最大负荷及日最小负荷的预测。对12个月共365天的独立样本试预报表明, 该客观方案对华中电网负荷的预测精度可满足业务调度的需要。  相似文献   

ARTIFICIAL NEURAL NETWORK CORRECTION OF ROUGH ERRORS OF OBSERVATIONS   总被引：1，自引：0，他引：1       下载免费PDF全文

蒋国荣  张韧  沙文钰  阎俊岳  姚华栋 《Acta Meteorologica Sinica》2002,(1)

In the context of tower measured radiation datasets.following the correction principle meetinga diagnostic equation in data quality control and in terms of a technique for model construction ondata and ANN(artificial neural network)retrieval for BP correction of radiation measurementswith rough errors available,a BP model is presented.Evidence suggests that the developed modelworks well and is superior to a convenient multivariate linear regression model,indicating its wideapplications.  相似文献   

矿产勘查与评估的统计地球化学方法   总被引：1，自引：0，他引：1  

蒋志 《地质与勘探》2002,38(1):1-4

统计地球化学在矿产勘查与评估中的应用，主要包括采术规则，临界品位计算，资源量／储量公式，边界品位确定，网度判别，矿床经济分类以及矿床开发风险等内容。  相似文献   

Structural damage detection using the optimal weights of the approximating artificial neural networks     

Shih‐Lin Hung  C. Y. Kao 《地震工程与结构动力学》2002,31(2):217-234

This work presents a novel neural network‐based approach to detect structural damage. The proposed approach comprises two steps. The first step, system identification, involves using neural system identification networks (NSINs) to identify the undamaged and damaged states of a structural system. The partial derivatives of the outputs with respect to the inputs of the NSIN, which identifies the system in a certain undamaged or damaged state, have a negligible variation with different system errors. This loosely defined unique property enables these partial derivatives to quantitatively indicate system damage from the model parameters. The second step, structural damage detection, involves using the neural damage detection network (NDDN) to detect the location and extent of the structural damage. The input to the NDDN is taken as the aforementioned partial derivatives of NSIN, and the output of the NDDN identifies the damage level for each member in the structure. Moreover, SDOF and MDOF examples are presented to demonstrate the feasibility of using the proposed method for damage detection of linear structures. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献