共查询到18条相似文献，搜索用时 265 毫秒
1.
Through the research into the characteristics of 7-DoF high dimensional nonlinear dynamics of a vehicle on bumpy road, the periodic movement and chaotic behavior of the vehicle were found.The methods of nonlinear frequency response analysis, global bifurcation, frequency chart and Poincaré maps were used simultaneously to derive strange super chaotic attractor.According to Lyapunov exponents calculated by Gram-Schmidt method, the unstable region was compartmentalized and the super chaotic characteristic of the nonlinear system was verified.Numerical results by 4-order Runge-Kutta method presented the multiform dynamic behavior of the system. 相似文献
2.
Probability density function (PDF) method is proposed for analysing the structure of the reconstructed attractor in computing the correlation dimensions of RR intervals of ten normal old men. PDF contains important information about the spatial distribution of the phase points in the reconstructed attractor. To the best of our knowledge, it is the first time that the PDF method is put forward for the analysis of the reconstructed attractor structure. Numerical simulations demonstrate that the cardiac systems of healthy old men are about 6 - 6.5 dimensional complex dynamical systems. It is found that PDF is not symmetrically distributed when time delay is small, while PDF satisfies Gaussian distribution when time delay is big enough. A cluster effect mechanism is presented to explain this phenomenon. By studying the shape of PDFs, that the roles played by time delay are more important than embedding dimension in the reconstruction is clearly indicated. Results have demonstrated that the PDF method represents a promising numerical approach for the observation of the reconstructed attractor structure and may provide more information and new diagnostic potential of the analyzed cardiac system. 相似文献
3.
QI Dong-lian WANG Qiao 《浙江大学学报(A卷英文版)》2006,7(12):1979-1983
INTRODUCTION Many people paid attention to passive theory and used it to control chaotic dynamical systems (Byrnes and Isidori, 1991; Yu, 1999). Yu (1999) studied the passive equivalence of the Lorenz chaotic system and presented the method of passive control of chaotic system. Using passive theory, Qi and Zhao (2005) researched on the control of Permanent Magnet Synchronous Motor chaotic system, and stabilized the system at different equilibrium points. However, in order to design th… 相似文献
4.
Nonlinear dynamics analysis of a new autonomous chaotic system 总被引：2，自引：0，他引：2
CHU Yan-dong LI Xian-feng ZHANG Jian-gang CHANG Ying-xiang 《浙江大学学报(A卷英文版)》2007,8(9):1408-1413
In this paper,a new nonlinear autonomous system introduced by Chlouverakis and Sprott is studied further,to present very rich and complex nonlinear dynamical behaviors. Some basic dynamical properties are studied either analytically or nu-merically,such as Poincaré map,Lyapunov exponents and Lyapunov dimension. Based on this flow,a new almost-Hamilton chaotic system with very high Lyapunov dimensions is constructed and investigated. Two new nonlinear autonomous systems can be changed into one another by adding or omitting some constant coefficients. 相似文献
5.
乔南 《中学数学教学参考》2008,(11)
Vectors may also be multiplied by a number. The productof the vector a by the number λ is defined as the vector a λ=λa, the absolute value of which is obtained by multiplying theabsolute value of the vector a by the absolute value of thenumber λ, i. e. |λa|=|λ||a|, the direction coinciding withthe direction of the vector a or being in the opposite sensedepending on whether λ>0 or λ<0. If λ=0 or a=0, then λ a 相似文献
6.
American eating is funny. They eat_1 everything with a fork, and it appears that _2 a knife in one's right hand longer than a few seconds is considered to be _3 good table manners.The system is that if it is really necessary to use a_4, people take thefork in their left hand, and cut off a piece of meat or whatever it is in the_5manner. Then they put the knife down, change the fork to their_6,and only then do they put the food to their mouth. This is clearly ridiculous,but it is considered good_7.There are several results of this system. First, if it is not really _8 to use a knife, Americans don't use _9, because obviously this greatly makes 相似文献
7.
Many complex dynamical networks display synchronization phenomena. We introduce a general complex dynamical network model. The model is equivalent to a simple vector model of adopting the Kronecker product. Some synchronization criteria, including time-variant networks and time-varying networks, are deduced based on Lyapunov＇s stability theory, and they are proven on the condition of obtaining a certain synchronous solution of an isolated cell. In particular, the inner-coupling matrix directly determines the synchronization of the time-invariant network; while for a time-varying periodic dynamical network, the asymptotic stability of a synchronous solution is determined by a constant matrix which is related to the fundamental solution matrices of the linearization system. Finally, illustrative examples are given to validate the results. 相似文献
8.
Kevin H. Ashford-Rowe Marnie Holt 《美中教育评论》2011,(3):317-322
The ＂emerging educational institutional decision-making matrix＂ is developed to allow educational institutions to adopt a rigorous and consistent methodology of determining which of the myriad of emerging educational technologies will be the most compelling for the institution, particularly ensuring that it is the educational or pedagogical but not the technological imperative that drives the technology integration agenda. The matrix is designed to be used after some initial research into an emerging technology. Once a technology is put through the matrix, a member of options are available： （1） shelving the technology; （2） putting the technology on hold and maintaining a watching brief until the technology matures in the market; and （3） researching the product further by conducting a trial or placing in testing sandpit. After further research, the technology can be tested as a pilot to determine how well or otherwise, the technology works within the institution. If an emerging technology has more than one product associated with it, a second and third step in the matrix has been developed, and the second step assigns a rating to each of the categories within the matrix. With many products containing similar features, a third step has been developed to compare products on a feature level. 相似文献
9.
During the decision-making process, especially in multi-disciplinary complex cases, assessment technique is needed to assist policy-makers in making the right decision. Many of such assessment techniques have been developed for policy-makers, but the inevitable subjectivity of policy-makers often becomes the main obstacle in making the right or proper policy. Interlink decision-making index （IDMI） is a newly proposed assessment method with the advantages of being simple to use and having less human interference over other methods, as it does not require a weighting process of each selection criterion. This paper implements IDMI to assist with decision-making in national or regional low-carbon development, using China as a case study. The Chinese government has annotmced its carbon emission reduction target along with other development targets by 2020. Many policy settings can be chosen in order to achieve those targets. The problem is how to determine the best setting and the means by which decision-makers can avoid subjectivity and extremes. A number of policy setting options are generated carefully by a system dynamic model under different policy scenarios. The IDMI demonstrates a perfect way to assist in selecting the ＂best＂ among all the options that can achieve the goals within the acceptable range. 相似文献
10.
Olga Denac 《美中教育评论》2009,6(10):54-60
Pedagogical theory and research practice tend to confine themselves to study the cognitive aspect of a child＇s personality and to focus on his/her productivity, while forgetting about other dimensions. The ability to experience artistic contents and the creative capacity of our society are decreasing. People are in a continuous search for spiritual balance and therefore the task of the contemporary school is to help people get out of this crisis and pay more attention to the realization of educational tasks and goals as well as individual school subjects. Art has always played the role of purposefully influencing the experiencing, feeling, creating and enjoying of beautiful things. It therefore provides a counterbalance to the rationalized world of today. Especially music plays a special role in all periods and all human societies, however, not because it encourages various experiences or notions in the listener or a pleasant atmosphere, but because it presents a challenge to the development of spiritual perception that does not occupy an important, enough place in the present school system. Based on different historical understandings of the pedagogical value of music, the author tries to determine what pedagogical value was ascribed to music in the past and what pedagogical value it is being ascribed today 相似文献
11.
提出一个新的混沌系统,分析了它的动力学性质,即平衡点的稳定性、耗散性、吸引子的存在性、Lyapunov指数、分数维、分岔图谱图、最大的Lyapunov指数图与庞开莱图,分析显示得到的系统是一个新的混沌吸引子． 相似文献
12.
构造了一个由两个子系统构成的混沌系统,分析了一个子系统的平衡点及在平衡点的特征值、分形维数、Lyapunov指数等性质,设计了一个由两个可切换混沌系统组成的实际电路并进行了实验,通过一个开关选择器,电路可以实现两个子系统的功能,观察到了两个子系统在各个相平面的混沌吸引子. 相似文献
13.
袁地 《安阳师范学院学报》2008,(5):27-31
通过数值计算、理论推导分析了一个类Lorenz混沌系统的基本动力学特性,并通过数值仿真、相图、Poincare截面图和功率谱研究了这个系统的混沌行为。然后,构建一个受控系统并利用Lyapunov指数谱、分叉图分析了该系统混沌吸引子的形成机制。结果表明．该系统混沌吸引子可由两个卷形状演化为一个卷形状,并最终通过倍周期分叉的过程演化为周期运动的形状。 相似文献
14.
WANG Ya-qin 《浙江大学学报(A卷英文版)》2007,8(10):1691-1694
Let K be a closed convex subset of a real reflexive Banach space E, T：K→K be a nonexpansive mapping, and f：K→K be a fixed weakly contractive （may not be contractive） mapping. Then for any t∈（0, 1）, let x1∈K be the unique fixed point of the weak contraction x1→tf（x）＋（1-t）Tx. If T has a fixed point and E admits a weakly sequentially continuous duality mapping from E to E^＊, then it is shown that {xt} converges to a fixed point of T as t→0. The results presented here improve and generalize the corresponding results in （Xu, 2004）. 相似文献
15.
The dilaton in Weyl-Scale induced gravitational theory is regarded as a candidate of dark energy. When the potential of dilaton field is taken as the form Wσ ＋ σ^2e^-βσ2, that there exist attractor solutions to the canonical dilatonic dark energy model and the phontam model, and these attractors correspond to an equation of state ω = -1 and a cosmic density parameter Ωσ = 1, which are important features for a dark energy model and can fit with the current observations. We find a sufficient condition of the existence of a late time de Sitter attractor. The attractor behaviors, the evolutions of the state parameter ω and the cosmic density parameter Ω, the evolution of X （σ/σ0） and Y （σ/σ0^2） with respect to N（ln a）are shown numerically. 相似文献
16.
Refined empirical line method to calibrate IKONOS imagery 总被引：1，自引：0，他引：1
XU Jun-feng HUANG Jing-feng 《浙江大学学报(A卷英文版)》2006,7(4):641-646
INTRODUCTION To extract quantitative biophysical parameter such as leaf biomass and leaf chlorophyll concentra- tion from the remotely sensed imagery accurately, the effects of atmospheric scattering and absorption must be removed. Atmospheric effects add to or diminish true ground reflectance, if the atmospheric spectral features are not properly removed. A significant analytical bias could be introduced for data interpre- tation (Ben-Dor and Levin, 2000). Many approaches have been deve… 相似文献
17.
一个混沌系统设计及其FPGA电路实现 总被引：1，自引：1，他引：0
提出了一个混沌系统,并利用理论和数值仿真对系统的基本特性进行了分析.通过Lyapunov指数谱和分岔图,对系统的状态转换进行了分析.为验证系统的混沌行为,在matlab的simulink下,利用DSP Builder设计了一个电路,并转换成VHDL代码程序,用Quartus II下载到FPGA硬件电路中进行了实验,实验结果与仿真结果完全一致,提出了一种基于FPGA平台和EDA开发工具实现混沌吸引子的新方法. 相似文献
18.
Yang Zhonghua 《上海大学学报(英文版)》1998,2(3):182-185
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