共查询到20条相似文献，搜索用时 125 毫秒
1.
The basic principle of infinite-dimensional dynamic system is to try to reduce the original infinite-dimensional system to an infinite-dimensional system. However,due to the unknown structure of the reduced system, it is difficult to describe its dynamical behaviour. To overcome this difficulty, the idea of approximate inertial manifolds is introduced, for NSE, the existence of AIM was studied, it is shown that the global attractor lies within a neighborhood of the graph of an Lipschitz function by the squeezing property. In this paper, by constructing a finite dimensional solution sequence, we will prove that it tends to the global attractor, theoretically, this provides a metod of constructing the asymptotic attractors, theoretically, this provides a method of constructing the asymptotic attractors for the evolution equations. 相似文献
2.
GPS/INS integrated systems are applied in the self-positioning of the high dynamic targets. This paper forms state equations and observation equations by the integrated system and GPS observation respectively. An adaptive filtering algorithm is introduced which estimates observation noise covariance with observation data, and estimates dynamic noise covariance by use of Sage-Husa filtering algorithm which has faster convergent speed and better stability than the conventional Kalman filtering algorithm. At last, simulations are given to verify the effectiveness of the algorithm. 相似文献
3.
Pan Jun Zhou Shouchang Huang Shanglian 《保鲜与加工》1997,(1):88-91
After studying the meaning of EEG signal processing using systems theory,the basic difficulties of the research on the EEG system and signal analysis are given,showing that it is hard to build model of the EEG system and signal.Hence,we introuduce the method of reconstructing the attractor in state spaces.Through the analysis of some experiments,the meaning of the presented method has been discussed. 相似文献
4.
This paper gives a brief presentation of the influence of different information structures on portfolio selection and some simple examples to demonstrate their basic algorithms. The first is the familiar mean_variance model. The model does not need more hypotheses on the motion of the asset price along the full continuous time axis,but sometimes many unanticipated computation problems may be involved because of the difficulty in computing the inverse of some matrices with high dimension. The second is the stochastic optimal control model. It is to solve a stochastic optimal control problem,which is often related to Hamilton_Jacobi_Bellman eqution.It results in solving partial differential equations of Riccati matrix differential equations. Their closed_form solutions are usually very hard to obtain. The last is the differential game model. The existence,uniqueness,and the computation for its equilibrium solution are all very difficult mathematical problems. 相似文献
5.
Marcello Donatelli Gianni Bellocchi Fioravante Fontana 《European Journal of Agronomy》2003,18(3-4):363-367
RadEst3.00 estimates and evaluates daily global solar radiation values at given latitudes. Radiation is calculated as the product of the atmospheric transmissivity of radiation times the radiation outside the earth atmosphere. Four models estimate the atmospheric transmissivity, based on the daily temperature range. Model parameters can be fitted over one or more years of data by iterative procedures. Graphical and statistical evaluations of the estimates are presented. Reports of the analysis can be exported in a variety of formats. Penman–Monteith or Priestley–Taylor reference evapotranspiration is estimated, using both measured and estimated radiation. Utilities are provided to process numerous files, or correct possible constant biases in the data. Samples of data for tropical and temperate sites are supplied with the software. 相似文献
6.
The correlation dimension for the time series of blast furnace process varisble,such as blast volume, burden pressure drop and blast pressure etc.,have been estimated by using GP and modified GP algorithms.The predictublity analysis for the process variables have also been investigated.The results show that it is difficult to determine the chaotic attractor of blast furnace condition.It has been found that the predictablity for process variables can be used to niterpret and identity the precursor of biast furnace condition. 相似文献
7.
ABSTRACT Owing to its competitive labor costs, its open‐market policy, and a substantial amount of capital investments, China has become a global manufacturing pole and an export‐based economy replicating the conventional Asian model but on a much wider scale. This is creating acute competition on other Asian export‐based economies such as Korea that have to adapt to the “China effect.” Consequently, many Korean manufacturing companies have repositioned their capital and equipment in China to enlarge their market potential as well as to reduce their production costs. Because Korea is adjacent to China—both are sharing the Yellow Sea Rim—this shift is creating a unique geographical dimension with a high level of functional integration of Sino‐Korean manufacturing supply chains. This transition has also brought substantial changes in the regional logistic network by organizing new flows of raw materials, parts, and final products, most of them along the Yellow Sea Rim. New logistic flows have given substantial influences on regional port competition by creating diverse links. These changes are bringing a reorientation of the regional maritime industry and of the port system. 相似文献
8.
《保鲜与加工》2003,(11):121-125
ased on the average depth's momentum equation of two dimension which observe the momentum conservation,the numerical simulation of velocity distribution in aha reservoir is presented. According to the property of pollutant while they are in convective diffusion or transplant and degradation, the model simulates organics convective diffusion and heavy metal transplantion. In the end, some forecast are presented for typical organics and heavy metal pollutant at abundant season and medium season in the future of ten years and some proposal are given for dispose. 相似文献
9.
采用分形理论中的计盒维数、信息维数和关联维数对长汀县石峰寨桂花野生种群分布格局的多尺度分布规律进行比较分析。结果表明,桂花野生种群的分布格局具有分形特征,其计盒维数为0.8622～1.0058,信息维数为0.8670～0.9849,关联维数为1.0037～1.0757。桂花种群的计盒维数、信息维数、关联维数相差不大,表明该种群的分布格局强度相对复杂,局域空间占据较强,具有集聚分布的趋势。 相似文献
10.
In this paper,we make an attempt to study forced vibrations of the nth-order linear neutral delay differential equations with real constant coefficients. Sufficient and necessary conditions of the existence and uniqueness of periodic solutions for the equations are obtained by use of theory of Pourier series. Furthmore ,some brief and practical critiria are given. 相似文献
11.
用广东省中山市1955-2017年日平均气温时间序列分析周期与混沌性质。结果表明,功率谱为363d左右的年周期变化,为周期吸引子；是太阳直射点在南北移动导致。在滤去频率范围为0~0.005/d的年周期变化信息以后,功率谱呈连续谱；最大Lyapunov指数是正的,关联维数为10.1,表明高频气温变化部分具有混沌性。 相似文献
12.
ZHONG Yuan -chang 《保鲜与加工》2002,(7):30-32
To improve the quality of the self-positioning of airship around the earth, and not to lead to the increasing of volume and weight of the positioning systems of airship, the GPS/INS integrated positioning systems are constituted with close integrated pattern. The paper researches its application in the self-positioning of airship around the earth. According to real state of the airship, this paper forms its error state equations and integrates observation equations. Simulation results show that the integrated positioning system not only can pledge its high positioning precision but also can adapt target's quick moving. 相似文献
13.
You lihua Wu Huibi Sun Renbo Wang Daivu 《保鲜与加工》1992,(4):48-53
The basic equations of wall plates of MAN' S dry gas holders are derived in this paper. According to the law of cylindrical bending given by the finite element results .we derive some approximate formula calculating the deflection and stresses of the wall plates from the basic equations. Compared with the known approximate calculating method.the method car. obviously increase the percision. 相似文献
14.
Based on the differential scheme,presents a numerical method of pricing for American put options.Firstly,the partial differential equation satisfied by the option price is transformed into a series of differential equations.Then,these differential equations are solved by the iterative method.The numerical method includes the implicit finite difference method and the explicit finite difference method and these two methods are compared.Finally,a numerical example is given and the validity of the algorithm is checked by a series of experiments.Some useful results are obtained for its application in the option markets. 相似文献
15.
This.paper derives the basic solution of elastic half-space foundation plate byHankel transform,Then its boundary integral equation of distortion is estabished,The paper discuss-es bou ndary integral equation on plate of fixxing and/or simple support boundary.Then a systemof algebraic equations for the boundary values are established.A numerical example is given , its re-sult shows that this Method is correct. 相似文献
16.
QIU Li qiong 《保鲜与加工》2002,(9):63-65
The transformation of even dimension to non even dimension usually need the special solution of a certain problem. This paper discusses method to find special solution of elastic plane problem is worth for practical purpose. The methods of finding special solution of displacement and stress for elastic plane problem are given for non even limens ion displacement method and stress function method respectively, and the problem are transformed into even dimension. Several concrete special solutions and applications are included. 相似文献
17.
Regionalisation or Globalisation of Automotive Production Networks? Lessons from Import Patterns of Four European Countries 
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下载免费PDF全文 The automotive industry has long had a reputation for organising its production networks on a macro‐regional scale. However, over the 2000–2012 time span, extended vertical disintegration of both carmakers and mega‐suppliers, and the 2008–2009 trade collapse suggest that this geographical organisation pattern could have weakened, giving way to a genuine globalisation of auto‐parts trade. This paper first reviews arguments likely to explain why automotive production networks are multi‐scalar, ranging from local to global. Empirical analysis of international auto‐parts trade data from Germany, France, UK, and Spain suggests that there has been little progression in globalisation of production networks. General data features can be best explained as follows: 1) the auto‐parts import level of a given country is mainly driven by its automobile production level, and by the degree of presence of foreign headquartered carmakers; and 2) the breakdown of imports into procurement flows from near‐distant and far‐distant countries is mainly driven by the degree of presence of carmakers headquartered in far‐distant countries. 相似文献
18.
甘蓝型冬油菜(Brassica napus)干物质积累、分配与转移的特性研究 总被引：23，自引：3，他引：23
采用不同的模型, 定量地研究了不同播期不同基因型油菜干物质积累、分配与转移规律. 结果表明: 油菜总干物质积累动态可拟合成Logistic模型. 油菜根、茎枝、叶干物质分配呈现出多项式函数的变化规律, 角果干物质分配表现为Logistic曲线的变化特征. 晚播油菜干物质冬前优先分配给叶, 角果发育成熟期优先分配给角果并主要给籽粒 相似文献
19.
In this paper a posteriori error estimates for Galerkin approximation of general operator equations is firstly presented in the framework of Sobolev spaces. Then a practical posteriori error estimates formula for the adaptive boundary element method solving the acoustic scattering problem with a finite plane screen is obtained by triangulations. The mathematical model of this problem is the three dimensional Neumann boundary value problem of Helmholtz equation with finite plane boundary. 相似文献
20.
Based on one dimensional constitutive equations of Revlon materials and the motion equations of the cable, the partial differential equations of the viscoelastic cable in inner and outer of plan under the gravity are investigated. Using Galerkin's method, a system of nonlinear ordinary equations is obtained. The analysis methods of the dynamic stability of viscoelastic cable are given. Finally, the effect of dynamic response of the cable, which is produced by elastic and viscoelastic parameters, is testified by the research of digital simulation. 相似文献