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排序方式: 共有234条查询结果,搜索用时 62 毫秒
221.
By using the concept of volume introduced by Nakamura in relativistic thermodynamics, a relativistic thermodynamical theory is proposed. A comparison is presented between the new theory, the van Kampen covariant theory and the Rohrlich proposal. A relativistic thermometer is proposed by using the Unruh-DeWitt detector. 相似文献
222.
Y. Zhang H.A. Cerdeira G. Hu 《The European Physical Journal B - Condensed Matter and Complex Systems》2001,23(1):97-102
A ring of diffusively coupled R?ssler oscillators, which can develop the conventional rotating wave from high-dimensional
chaos by increasing the coupling ɛ continuously is studied. The chaotic generator for the rotating wave emerges around ɛ =
ɛ, where the topological transition induced by the coupling not only changes the topological structure of all the oscillators,
which share a common strange attractor, but also changes them into being different from each other. Starting from this transition,
infinitely long range temporal correlation and spatial order in the style of antiphase state are established gradually, which
gives rise to the chaotic generator of the rotating wave.
Received 15 March 2001 相似文献
223.
协方差的二次型容许估计 总被引:2,自引:0,他引:2
本文研究方差的二次型估计的容许性,在平方损失下,我们给出了一个二次型估计在二次型估计类中是协方差的容许估计的充要条件。 相似文献
224.
在随机过程的理论及其应用中.Wiener过程起着基本的作用.本文结出用矩阵的初等变换,建立Wiener过程p.d,f的一个崭新的方法;此方法,对理解过程的统计特性,掌握过程的p,d,f的结构等,均是有益的. 相似文献
225.
Trbovic N Smirnov S Zhang F Brüschweiler R 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2004,171(2):248-283
Covariance NMR is demonstrated for homonuclear 2D NMR data collected using the hypercomplex and TPPI methods. Absorption mode 2D spectra are obtained by application of the square-root operation to the covariance matrices. The resulting spectra closely resemble the 2D Fourier transformation spectra, except that they are fully symmetric with the spectral resolution along both dimensions determined by the favorable resolution achievable along omega2. An efficient method is introduced for the calculation of the square root of the covariance spectrum by applying a singular value decomposition (SVD) directly to the mixed time-frequency domain data matrix. Applications are shown for 2D NOESY and 2QF-COSY data sets and computational benchmarks are given for data matrix dimensions typically encountered in practice. The SVD implementation makes covariance NMR amenable to routine applications. 相似文献
226.
227.
The asymptotic distribution of some test criteria for a covariance matrix are derived under local alternatives. Except for the existence of some higher moments, no assumption as to the form of the distribution function is made. As an illustration, a case of t distribution included normal model is considered and the power of the likelihood ratio test and Nagao's test for sphericity, as described in Srivastava and Khatri and Anderson, is computed. Also, the power is computed using the bootstrap method. In the case of t distribution, the bootstrap approximation does not appear to be as good as the one obtained by the asymptotic expansion method. 相似文献
228.
N. Impollonia 《Chaos, solitons, and fractals》1998,9(12):957-1996
In this study we derive, apparently for the first time in the literature, some exact solutions for the shear beams with stochastic flexibility, when these beams are acted upon by the random loading. The importance of these solutions lies in the fact that they can serve as benchmark solutions, to which the approximate solutions of various nature can be compared. Then we formulate stochastic variational principles, the first principle governs the behavior of the mean displacement, whereas the second principle is satisfied by the displacements covariance function. These variational principles allow us to formulate approximate techniques for the cases in which the exact solution is presently unavailable. In particular, we develop a stochastic version of the Rayleigh–Ritz method. Several examples are evaluated to shed more light on the probabilistic behavior of randomly excited structures possessing random flexibility. 相似文献
229.
230.