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Sierpinski Gasket上布朗运动的维数性质
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作者 李俊平 侯振挺 《系统科学与数学》 CSCD 北大核心 2003年第4期542-549,共8页
本文研究Sierpinski Gasket上的布朗运动X的象集、图集的Hausdorff维数性质,证明了存在零概率集Ⅳ,若ω∈Nc,则对任意紧集F(?)[0,∞),有(i)dimX(F+t)=min(α-1dimF,df),a.e.t>0,(ii)dimGrX|F+t=min(α-1dimF,(1-α)df+dimF),a.e.t>... 本文研究Sierpinski Gasket上的布朗运动X的象集、图集的Hausdorff维数性质,证明了存在零概率集Ⅳ,若ω∈Nc,则对任意紧集F(?)[0,∞),有(i)dimX(F+t)=min(α-1dimF,df),a.e.t>0,(ii)dimGrX|F+t=min(α-1dimF,(1-α)df+dimF),a.e.t>0,其中ds=log3/log2,α=log2/log5. 展开更多
关键词 布朗运动 维数性质 证明 概率性质
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SG(2,2)上布朗运动的维数性质
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作者 李俊平 《应用数学学报》 CSCD 北大核心 2000年第2期206-211,共6页
本文研究分形集合SG(2,2)上布朗运动的维数性质,得到了SG(2,2)上布朗运动的样本图以及象集的Hausdorff维数与盒维数.
关键词 分形集合 纳过程 维数性质 HAUSDORFF
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一种新的Z_p几何指标理论及其应用
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作者 郭志明 《广州大学学报(自然科学版)》 CAS 2008年第4期6-11,共6页
给出一种广义Zp几何指标理论,它是刘嘉荃,王志强,徐远通,Michalek R和Tarantello G等学者介绍的Zp指标的推广.对于某些非线性系统,该指标可以用来讨论其多重周期解和次调和解的存在性.利用广义Zp几何指标,结合Kaplan-Yorke的耦合系统方... 给出一种广义Zp几何指标理论,它是刘嘉荃,王志强,徐远通,Michalek R和Tarantello G等学者介绍的Zp指标的推广.对于某些非线性系统,该指标可以用来讨论其多重周期解和次调和解的存在性.利用广义Zp几何指标,结合Kaplan-Yorke的耦合系统方法,文章给出一类微分差分方程多重周期解存在性的一个条件. 展开更多
关键词 广义Zp指标 维数性质 Hamilon系统 多重周期解
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The algorithm of 3D multi-scale volumetric curvature and its application 被引量:12
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作者 陈学华 杨威 +2 位作者 贺振华 钟文丽 文晓涛 《Applied Geophysics》 SCIE CSCD 2012年第1期65-72,116,共9页
To fully extract and mine the multi-scale features of reservoirs and geologic structures in time/depth and space dimensions, a new 3D multi-scale volumetric curvature (MSVC) methodology is presented in this paper. W... To fully extract and mine the multi-scale features of reservoirs and geologic structures in time/depth and space dimensions, a new 3D multi-scale volumetric curvature (MSVC) methodology is presented in this paper. We also propose a fast algorithm for computing 3D volumetric curvature. In comparison to conventional volumetric curvature attributes, its main improvements and key algorithms introduce multi-frequency components expansion in time-frequency domain and the corresponding multi-scale adaptive differential operator in the wavenumber domain, into the volumetric curvature calculation. This methodology can simultaneously depict seismic multi-scale features in both time and space. Additionally, we use data fusion of volumetric curvatures at various scales to take full advantage of the geologic features and anomalies extracted by curvature measurements at different scales. The 3D MSVC can highlight geologic anomalies and reduce noise at the same time. Thus, it improves the interpretation efficiency of curvature attributes analysis. The 3D MSVC is applied to both land and marine 3D seismic data. The results demonstrate that it can indicate the spatial distribution of reservoirs, detect faults and fracture zones, and identify their multi-scale properties. 展开更多
关键词 3D multi-scale volumetric curvature adaptive differential operator in wavenumber domain multi-frequency expansion in time-frequency domain fault detection fracture zone data fusion
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Some New Properties of Wigner Function Studied in Entangled State Representation
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作者 范洪义 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第8期241-243,共3页
Based on the Wigner operator in the entangled state representation we study some new important propertiesof Wigner function for bipartite entangled systems,such as size of an entangled state,upper bound of Wigner func... Based on the Wigner operator in the entangled state representation we study some new important propertiesof Wigner function for bipartite entangled systems,such as size of an entangled state,upper bound of Wigner functions,etc.These discussions demonstrate the beauty and elegance of the entangled state representation. 展开更多
关键词 Wigner function entangled state representation Wigner operator
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Effects of negative index medium defect layers on the transmission properties of one-dimensional photonic crystal 被引量:1
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作者 XIANG Yuan-jiang DAI Xiao-yu WEN Shuang-chun 《Optoelectronics Letters》 EI 2007年第2期144-147,共4页
The photonic band gap structure of 1D photonic crystal with a negative index medium defect layer is studied by using the transfer matrix method. Investigations show that the introdufion of negative index medium defect... The photonic band gap structure of 1D photonic crystal with a negative index medium defect layer is studied by using the transfer matrix method. Investigations show that the introdufion of negative index medium defect layer and the increase of the negative index value will result in an extension of the band gap. Moreover, by increasing the negative index, the width of defect layer and the numbers of period photonic crystal, the width of defect modes will be narrowed, which is advantaged to obtain optical filters with narrow band. Finally, the effects of absorption on the properties of band gap and on defect modes have been discussed. 展开更多
关键词 光子晶体 传输性质 负系介质 缺陷层 带隙结构
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Magnetic and Magneto-Optical Properties in Paramagnetic NdF3 Under High Magnetic Field
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作者 WANGWei LIUGong-Qiang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第5期948-952,共5页
In this paper, we first theoretically report the magnetic and magneto-opticalproperties in paramagnetic media under high external magnetic field. Considering the action of theexternal magnetic Geld H_e and indirect ex... In this paper, we first theoretically report the magnetic and magneto-opticalproperties in paramagnetic media under high external magnetic field. Considering the action of theexternal magnetic Geld H_e and indirect exchange interaction H_v, the characteristic of the magneticsaturation and the property of the Faraday rotation to be nonlinear with external magnetic Geld arepresented in paramagnetic NdF_3. In terms of our theory, the indirect exchange interaction plays auimportant role in the magnetization M and the Faraday rotation θ in NdF_3 under high externalmagnetic Geld. The theory is in good agreement with experimental results. On the other hand, areasonable explanation for the temperature dependence of the ratio of the Verdet constant to themagnetic susceptibility V/x is obtained. 展开更多
关键词 magneto-optical property verdet constant exchange interaction highmagnetic field NONLINEAR
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Investigation on thermophysical properties of reactive powder concrete 被引量:13
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作者 JU Yang LIU HongBin +3 位作者 LIU JinHui TIAN KaiPei WEI Song HAO Song 《Science China(Technological Sciences)》 SCIE EI CAS 2011年第12期3382-3403,共22页
The thermophysical properties,such as thermal conductivity,thermal diffusivity,specific heat capacity and linear thermal expansion of reactive powder concrete(RPC) with different steel fiber volumetric fractions are i... The thermophysical properties,such as thermal conductivity,thermal diffusivity,specific heat capacity and linear thermal expansion of reactive powder concrete(RPC) with different steel fiber volumetric fractions are investigated by means of high temperature tests. The thermophysical characteristics of RPC with different fiber volumes under different temperatures are analyzed and compared with those of the common high-strength concrete and high-performance concrete. The empirical relationships of thermophysical properties with temperature and fiber volume are identified. By the heat transfer and solid physics methods,the microscopic physical mechanism of heat transfer process and heat conduction properties of RPC are investigated,and the theoretical formulas of specific heat capacity and thermal expansion coefficient are derived,respectively. The effects of temperature and steel fibers on the specific heat capacity and the thermal expansion coefficient are quantitatively analyzed and the discriminant conditions are provided. It is shown that the experimental results are consistent with the theoretical prediction. 展开更多
关键词 reactive powder concrete (RPC) thermophysical properties high temperature fiber reinforcement heat conduction specific heat capacity thermal expansion coefficient
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Asymptotic properties of Lasso in high-dimensional partially linear models 被引量:3
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作者 MA Chi HUANG Jian 《Science China Mathematics》 SCIE CSCD 2016年第4期769-788,共20页
We study the properties of the Lasso in the high-dimensional partially linear model where the number of variables in the linear part can be greater than the sample size.We use truncated series expansion based on polyn... We study the properties of the Lasso in the high-dimensional partially linear model where the number of variables in the linear part can be greater than the sample size.We use truncated series expansion based on polynomial splines to approximate the nonparametric component in this model.Under a sparsity assumption on the regression coefficients of the linear component and some regularity conditions,we derive the oracle inequalities for the prediction risk and the estimation error.We also provide sufficient conditions under which the Lasso estimator is selection consistent for the variables in the linear part of the model.In addition,we derive the rate of convergence of the estimator of the nonparametric function.We conduct simulation studies to evaluate the finite sample performance of variable selection and nonparametric function estimation. 展开更多
关键词 Lasso irrepresentable condition restricted eigenvalue semiparametric models sparsity
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