期刊文献+
共找到3篇文章
< 1 >
每页显示 20 50 100
不确定性河流水质模型的应用及进展 被引量:3
1
作者 许劲 龙腾锐 《中国给水排水》 CAS CSCD 北大核心 2007年第16期4-8,共5页
明确了河流水质模型由确定性向不确定性发展的趋势,指出现有河流水质模型大多建立在菲克扩散定律基础上。分析了河流水质模型中不确定性的来源,重点论述了随机水质模型的研究现状,并将其分为随机游动型、随机变量型和随机过程型三类,明... 明确了河流水质模型由确定性向不确定性发展的趋势,指出现有河流水质模型大多建立在菲克扩散定律基础上。分析了河流水质模型中不确定性的来源,重点论述了随机水质模型的研究现状,并将其分为随机游动型、随机变量型和随机过程型三类,明确了随机微分方程水质模型与简化型的区别在于是否给出随机扰动强度的表达式,强调随机微分方程类水质模型是其发展方向,建议综合考虑不确定性和非线性,并从风险评价的高度来研究新的不确定性水质模型。 展开更多
关键词 不确定性河流水质模型 随机变量 随机过程 随机微分方程 随机扰动强度
下载PDF
Subspace identification for a stochastic model of plague 被引量:4
2
作者 Miao Yu Jianchang Liu 《International Journal of Biomathematics》 2016年第5期85-105,共21页
In this paper, a stochastic model of plague is first studied by subspace identification. First, the discrete model of plague is obtained based on the classical model. The corresponding stochastic model is proposed for... In this paper, a stochastic model of plague is first studied by subspace identification. First, the discrete model of plague is obtained based on the classical model. The corresponding stochastic model is proposed for the existence of stochastic disturbances. Second, for the model, the parameter matrices and noise intensity are obtained. Finally, the simulations of the model show that the subspace identification is more precise than least square method. 展开更多
关键词 Subspace method system identification stochastic biological model PLAGUE
原文传递
Stochastic dynamic simulation of the 100-kyr cycles in climate system
3
作者 DUAN MingKeng ZHOU XiuJi 《Science China Earth Sciences》 SCIE EI CAS CSCD 2015年第3期420-428,共9页
Based upon the stochastic resonance theory,the formation mechanism of 100-kyr cycles in climate system is numerically studied in the perspective of stochastic dynamics.In this study,firstly we combine the idealized al... Based upon the stochastic resonance theory,the formation mechanism of 100-kyr cycles in climate system is numerically studied in the perspective of stochastic dynamics.In this study,firstly we combine the idealized albedo model with the geological evidence and observation in climate system to construct a new albedo model.Secondly,a bistable nonlinear system is constructed by introducing the albedo model into zero-dimensional energy balance model.Finally,based on this new system,with the solar radiation cycles and stochastic perturbation simultaneously taken into account,the variation of 100-kyr cycles is analyzed by numerical simulations.The results show that,when the noise intensity reaches a certain value,the stochastic resonance can be triggered.However,the noise intensity in this level does not exist in the actual climate system.In order to explain the formation mechanism of 100-kyr glacial-interglacial cycles forced by the weak solar radiation cycles,besides the solar radiation stochastic perturbation,the stochastic dynamic effects of the other "non-solar" radiation stochastic perturbation in the climate change processes should also be considered.The stochastic dynamic simulations taking the two types of stochastic perturbation into consideration show that,when the two types of appropriately observable stochastic perturbation are introduced,the stochastic resonance also can be generated.In this situation,the contribution rate of solar radiation stochastic perturbation is about 38%,which proves the importance of solar radiation stochastic perturbation in the formation of 100-kyr climate cycles. 展开更多
关键词 solar radiation climate change stochastic dynamics stochastic resonance energy balance model
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部