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101.
J. Kumi
k 《Annalen der Physik》1995,507(8):805-808
Nonlinear generalization of autoregressive sequence of first order is used as basis for construction of mathematical model of bistable burst noise. It is proved that the noise generated using such a model has Lorentzian spectrum after clipping the white noise component. In passing it is demonstrated that random telegraph signal is obtainable by simple iteration. The proposed model suggests that one should expect to observe temperature dependence of frequency of transitions between the two levels of burst noise waveform. 相似文献
102.
本文从应用角度,对片式消声器的结构,消声机理,设计原则等作了较为全面的阐述,介绍了应用实例,结合工程实践,提出了一个估算存在气流时消声系数的经验公式。 相似文献
103.
104.
The impact of observational noise on the analysis of scale-free networks is studied. Various noise sources are modeled as random link removal, random link exchange and random link addition. Emphasis is on the resulting modifications for the node-degree distribution and for a functional ranking based on betweenness centrality. The implications for estimated gene-expressed networks for childhood acute lymphoblastic leukemia are discussed. 相似文献
105.
Summary We derive an explicit form for the current correlation function of a Fermi gas in a finite sample at arbitrary degree of degeneracy.
The expression so found enables a continuous investigation from diffusive to ballistic transport regimes to be carried out.
For degenerate one-dimensional conductors under ballistic regime we find that the noise spectral density exhibits characteristic
geometrical resonances and its low-frequency value has the universal formS
I
(0)=8e
2
KT/h, implying a universal conductanceG=2e
2/h. 相似文献
106.
Apartments that are exposed to the same level of road traffic noise on front of the most exposed façade often have very different neighbourhood soundscapes. In the first part of this paper, a neighbourhood soundscape adjusted exposure indicator, NALden, is derived. NALden-values are designed to be used as input to traditional exposure-effect relationships to improve annoyance impact estimates. In the second part, generic spatial procedures are developed and implemented. These produce map presentations in the form of contiguous neighbourhood quality areas. The quality of each neighbourhood is determined from the predicted annoyance impacts for residents. Noise impact maps provide experts, politicians, and the public with high-level impact visualizations of condensed status, “what-if” and scenario information. Results and illustrations are based on data from the Norwegian socio-environmental survey database, and a comprehensive national noise mapping effort. The methodology should work well for mapping Europe’s “black” and “grey” areas. 相似文献
107.
A review of commonly used analytical and empirical formulae for predicting sound diffracted by a thin screen 总被引:2,自引:0,他引:2
This paper reviews some useful analytical and empirical formulae that are used for the calculation of sound diffracted by a barrier. A brief historic overview of the study of spherical waves diffracted by a rigid half plane is presented also. The physical principles of sound diffraction by a thin plane are explained. The mathematical expressions are cast in a convenient form for ease of numerical implementation. Accurate analytical solutions are expressed in terms of standard mathematical functions that can be computed readily. Among the approximate solutions quoted, quite a few empirical formulations are adequate for most engineering purposes. The information presented in this paper should also be helpful for those who are interested in the study of sound diffracted by a barrier in a room or in a long industrial space. 相似文献
108.
109.
本文根据系统辨识与现代控制理论的观点,主要论述了数控机床伺服进给系统的振动与噪声的控制.文中提出的数值计算方法不仅可以有效地抑制伺服系统的振动与噪声,而且也大大改进了系统的伺服性能。 相似文献
110.