共查询到20条相似文献,搜索用时 9 毫秒
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Rui Kuang Wen-Chiao Cheng Dongkui Ma 《Dynamical Systems: An International Journal》2014,29(2):239-254
The aim of this paper is to introduce the lower s-topological entropy to distinguish zero entropy systems. That this quantity is an invariant factor under topological conjugacy and a power rule is shown. Some examples are given to show that the lower entropy dimension can attain any value in (0, 1), and are different with the upper one and the entropy dimension in the sense of Bowen. A counterexample is used to indicate that the product rule does not hold, and the lower s-topological entropy of the subsystem for the non-wandering set can be strictly less than that of the system when 0 < s < 1. Finally, this study also constructs a dynamical system to show that the transitive system with zero entropy dimension may not be minimal. 相似文献
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Ping Huang 《Dynamical Systems: An International Journal》2019,34(2):259-273
In this paper, using spanning sets in mean metrics we construct a new definition of measure-theoretic pressure of ergodic measures over a topological dynamical system. And we establish a pressure version of Katok's entropy formula in the case of mean metrics. Furthermore, we also introduce a new definition of topological pressure by replacing the Bowen metrics with the corresponding mean metrics, and prove that the new topological pressure is equivalent to the classical topological pressure. Then the variational principle for the newly defined topological pressure is obtained. 相似文献
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Similar with the fractal dimension, we introduce the concept of topological entropy dimension to classify the sets with entropy zero. We prove that the entropy dimension of the space in this article is not greater than that defined by De Carvalho, where he introduced the entropy dimension for the system, and give some examples indicating that such inequality is optimal. Some basic propositions of entropy dimension are discussed and it turns out that the entropy dimension is invariant under conjugacy. The property of the countable stability and a power rule for the entropy dimension of any set are obtained. It is shown that any set shares the same entropy dimension with its image set. 相似文献
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In this paper, we advance the entropy theory of discrete non-autonomous dynamical systems that was initiated by Kolyada and Snoha in 1996. The first part of the paper is devoted to the measure-theoretic entropy theory of general topological systems. We derive several conditions guaranteeing that an initial probability measure, when pushed forward by the system, produces an invariant measure sequence whose entropy captures the dynamics on arbitrarily fine scales. In the second part of the paper, we apply the general theory to the non-stationary subshifts of finite type, introduced by Fisher and Arnoux. In particular, we give sufficient conditions for the variational principle, relating the topological and measure-theoretic entropy, to hold. 相似文献
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论文分析总结了工程爆破界对于爆破振动速度计算的经验公式。根据相似理论,推导了爆破振动速度计算的公式。研究结果发现,在地形、地质和使用炸药种类不变的情况下,爆破引起的地面振动速度与最大起爆药量Q、爆源距测点的直线距离R、以及爆破作用指数n有关。只有在集中药包、标准抛掷爆破条件下,爆破振动速度的计算公式,才适合于前苏联学者萨道夫斯基提出的经验公式。论文把深孔直列药包,假定为无数个等效集中药包,提出了深孔爆破的振动速度计算公式,并进行了工程实际应用 相似文献
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The dynamics of a truss structure with several bars and nodes is investigated. The bars are made of some nonlinear material
and the truss structure shows large displacements under some time-dependent loads. The resulting equations are an example
of a model which governs the motion of a general MDOF structure after some discretization procedure, like FEM. Attention is
focused on the response strangeness met during the numerical integration of the motion equations. As a principal tool of investigation,
one uses the Kolmogorov entropy, the value of which is able to detect the sensitivity to initial conditions. The material
can present either nonlinear elastic softening or elasto-plastic behaviour.
This research has been supported by grants from the Italian Ministry of University and Scientific and Technological Research
(MURST). 相似文献
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建立了单根多楔带附件驱动系统的旋转振动方程的通程化方法,以适用于不同布置形式的单根多楔带附件驱动系统的旋转振动特性计算。在此基础上,开发了一个单根多楔带附件驱动系统旋转振动特性的计算程序,并利用该程序对两个不同布置形式的多楔带附件驱动系统的旋转振动特性进行了计算。计算得到了这两个不同布置形式的多楔带附件驱动系统的固有频率、带的稳态张力、轮和张紧臂的角度波动、带段的动态张力和最大轮毂载荷等。将部分计算值和实测值进行对比,验证了本文所建立的通程式方法的可行性。 相似文献
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分析了引起粗糙集中不确定性的因素,对已有的测量不确定性的粗糙度与粗糙熵方法进行了比较,提出了一种修正的粗糙熵方法,证明了此粗糙熵的性质,并将基于等价关系的修正粗糙熵拓展到基于一般二元关系下的广义修正粗糙熵,同时给出了广义修正粗糙熵的定义及性质.通过分析和实例可以看出,所提出的修正粗糙熵方法可以用来更合理、更精确地测量粗糙集中的不确定性. 相似文献
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To analyse the component of fuzzy output entropy, a decomposition method of fuzzy output entropy is first presented. After the decomposition of fuzzy output entropy, the total fuzzy output entropy can be expressed as the sum of the component fuzzy entropy contributed by fuzzy inputs. Based on the decomposition of fuzzy output entropy, a new global sensitivity analysis model is established for measuring the effects of uncertainties of fuzzy inputs on the output. The global sensitivity analysis model can not only tell the importance of fuzzy inputs but also simultaneously reflect the structural composition of the response function to a certain degree. Several examples illustrate the validity of the proposed global sensitivity analysis, which is a significant reference in engineering design and optimization of structural systems. 相似文献
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提出一种基于排列熵及其改进理论的伪相平面法,从而可以提取非线性系统中的微弱周期信号特征。通过选择合理的时间延迟和嵌入维数,对Duffing系统的响应信号进行相空间重构,得到一次排列熵和二次排列熵。随后将位移激励、一次排列熵和二次排列熵作为数据集,组成位移激励-一次排列熵和位移激励-二次排列熵两种伪相平面。通过将这两种方法与传统的相平面法、频谱分析和排列熵、排列熵谱、二次排列熵、二次排列熵谱的提取效果进行对比,验证了该方法的合理性。研究表明该方法能够对非线性系统中的微弱周期信号特征进行提取,取得了较好效果。 相似文献
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By using the Fresnel operator we derive a multiplication rule for the Collins diffraction formula; the inverse of Collins diffraction integration can also be conveniently derived in this way in the context of quantum optics theory. 相似文献
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Entropy generation in a counterflow heat exchanger has been analysed in detail and expressions have been derived in terms of relevant non dimensional parameters. In the case of nearly ideal heat exchangers with nearly balanced capacity rate, an expression for entropy production has been derived which matches closely with exact calculation. 相似文献
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关于 Stirling公式的一个注记 总被引:2,自引:0,他引:2
谢庭藩 《中国计量学院学报》2000,11(2):110-114
记 rn=nne- n 2πn.这个注记证明 ,当 n≥ 1 0时rn 1 +11 2 n+ 12 88n2 +2 4 9.2 n 相似文献
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基于熵技术的矿山安全模糊综合评价 总被引:6,自引:1,他引:6
根据矿山安全评价所存在的模糊性和随机性的特点,在建立多级模糊综合评价的指标体系的基础上,借用信息论中熵的概念计算客观权重的方法,运用模糊数学理论,建立二级模糊综合评价模型,提高了矿山安全现状评价的客观性和科学性,具有一定的工程实际应用价值. 相似文献