共查询到18条相似文献,搜索用时 136 毫秒
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导出了6N维和6维相空间的熵产生率,即熵增加定律的一个统计公式:P=kD(Δqθ)2,即熵产生率P等于扩散系数D、离开平衡率θ的空间梯度平方的平均值与Boltzm ann常数k 三者之乘积.指明非平衡系统的宏观熵产生是由其微观状态数密度在空间随机地不均匀离开 平衡引起的.作为公式的应用,研究了气体自由膨胀、布朗运动及固体变形和断裂三个非平衡 态课题,给出了它们的熵产生及其一次和二次时间变化率,得到了不可逆过程的系统内对应 的微观结构变化是不均匀的推论.进而导
关键词:
熵产生率
微观状态数密度
离开平衡率
随机扩散 相似文献
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本文主要研究了关联乘性非高斯噪声和加性高斯白噪声共同激励的FHN(Fitz Hugh-Nagumo)神经元系统.利用路径积分法和统一色噪声近似,推导出该系统的定态概率密度函数表达式.通过研究发现,乘性噪声强度D、加性噪声强度Q、噪声自关联时间τ以及互关联系数λ均可以诱导系统产生非平衡相变现象,而非高斯参数q却不可以诱导系统产生非平衡相变现象.此外,我们还发现参数D和λ的增大有利于神经元系统从激发态向静息态转换,Q和τ的增大有利于神经元系统从静息态向激发态转换,q的增大会使得神经元系统停留在静息态的概率增加. 相似文献
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研究了负P表示非经典光场的Wehrl熵和Shannon熵与场参数m和平均光子数(-n)的关系,结果显示,负P表示的非经典光场的Wehrl熵随着场参数m和平均光子数的增大而减小,当(-n)增大到一定程度时Wehrl熵趋向于一个不变的常数.用数值计算的方法研究了负P表示光场的Shannon熵与平均光子数(-n)的关系,结果表明,Shannon熵随着场参数m和平均光子数(-n)的增大而增大.同时发现,Wehrl熵随光场总噪声的增大而减小,Shannon熵随力学量起伏的减小而减小. 相似文献
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近几年兴起的基于最大相关熵准则的FxMCC(filtered-x maximum correntropy criterion)算法在有源噪声控制(active noise control, ANC)系统中取得了良好的降噪性能。然而,已有的FxMCC算法仅使用了单一的高斯核,算法在强脉冲噪声环境下降噪能力严重退化,且算法对核宽参数极敏感,不合适的核宽会降低算法降噪性能。为了弥补FxMCC算法的不足,本文引入异构混合相关熵,使用由高斯核和拉普拉斯核组成的混合核作为代价函数,推导了基于异构混合相关熵的FxMCC-MK(FxMCC-mixture kernels)算法。本文进一步分析了所提算法的收敛条件和稳定性,并与已有的算法进行了计算复杂度比较。仿真结果表明,在标准对称α稳定分布(symmetric α-stable, SαS)脉冲噪声和真实噪声录音的有源噪声控制中,相比于已有的相关熵算法,本文提出的FxMCC-MK算法具有更低的核宽参数敏感度,更强的鲁棒性和更快追踪能力。 相似文献
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信息熵、玻尔兹曼熵以及克劳修斯熵之间的关系--兼论玻尔兹曼熵和克劳修斯熵是否等价 总被引:6,自引:0,他引:6
论述了信息熵、玻尔兹曼熵以及克劳修斯熵之间的关系;由不涉及具体系统的方法从玻尔兹曼关系、信息熵推导出了克劳修斯熵的表达式;指出玻尔兹曼熵与克劳修斯熵不是等价关系,而是玻尔兹曼熵包含克劳修斯熵,信息熵又包含玻尔兹曼熵。 相似文献
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GUO Yong-Feng XU Wei LI Dong-Xi XIE Wen-Xian 《理论物理通讯》2008,49(6):1561-1566
A stochastic dissipative dynamical system driven by non-Gaussian noise is investigated. A general approximate Fokker-Planck equation of the system is derived through a path-integral approach. Based on the definition of Shannon's information entropy, the exact time dependence of entropy flux and entropy production of the system is calculated both in the absence and in the presence of non-equilibrium constraint. The present calculation can be used to interpret the interplay of the dissipative constant and non-Gaussian noise on the entropy flux and entropy production. 相似文献
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This paper shows the Fokker-Planck equation of a dynamical system driven by quasimonochromatic noise. Based on the Fokker-Planck equation and the definition of Shannon's information entropy, the exact time dependence of entropy flux and entropy production for the system is calculated. The relationship between the properties of quasimonochromatic noise and dissipative parameter and their effects on entropy flux and entropy production are discussed. 相似文献
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Time evolution of information entropy for a stochastic system with double singularities driven by quasimonochromatic noise 下载免费PDF全文
<正>This paper deals with the time evolution of information entropy for a stochastic system with double singularities driven by quasimonochromatic noise.The dimension of the Fokker-Planck equation is reduced by the linear transformation. The exact expression of the time dependence of information entropy is obtained based on the definition of Shannon’s information entropy.The relationships between the properties of dissipative parameters,system singularity strength parameter,quasimonochromatic noise,and their effects on information entropy are discussed. 相似文献
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Upper bound for the time derivative of entropy for a stochastic dynamical system with double singularities driven by non-Gaussian noise 下载免费PDF全文
A stochastic dynamical system with double singularities
driven by non-Gaussian noise is investigated. The Fokker--Plank
equation of the system is obtained through the path-integral
approach and the method of transformation. Based on the definition
of Shannon's information entropy and the Schwartz inequality
principle, the upper bound for the time derivative of entropy is
calculated both in the absence and in the presence of
non-equilibrium constraint. The present calculations can be used to
interpret the effects of the system dissipative parameter, the
system singularity strength parameter, the noise correlation time
and the noise deviation parameter on the upper bound. 相似文献
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Time dependence of entropy flux and entropy production for a dynamical system driven by noises with coloured cross-correlation 下载免费PDF全文
This paper shows the Fokker--Planck equation of a dynamical system
driven by coloured cross-correlated white noises in the absence and
presence of a small external force. Based on the Fokker--Planck
equation and the definition of Shannon's information entropy, the
time dependence of entropy flux and entropy production can be
calculated. The present results can be used to explain the extremal
behaviour of time dependence of entropy flux and entropy production
in view of the dissipative parameter γ of the system, coloured
cross-correlation time \tau and coloured cross-correlation strength
\la. 相似文献
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S.A. El-Wakil 《Journal of Quantitative Spectroscopy & Radiative Transfer》2006,102(2):162-171
By means of two alternative methods namely, the maximum entropy and Chapman-Enskog, flux limited approach the ion transport equation for slowing-down problem of low-energy light ions in solid has been solved explicitly. Maximum entropy technique yields approximate solutions in the form of locally Maxwellian distribution function, based on moments expansion truncated upon entropy maximization.The behavior of the approximate maximum entropy and the flux limited solutions have the same tendency. Knowing the distribution function obtained by flux limited approach, allows us to calculate directly the path length distributions of backscattered ions, and compared with that found by other theories such as Laplace-transform and double Legendre polynomial approximation. One can see that the flux limited approach is better than the previous method namely, (DPN) Laplace-transform.The results reported in this article provide further evidence of the usefulness of both maximum entropy and flux limited for obtaining the solution of ion transport equation in compact form. 相似文献
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阐述了以表述信息演化规律的信息(熵)演化方程为核心的非平 衡统计信息理论.推导出了 Shannon信息(熵)的非线性演化方程,引入了统计物理信息并 推导出了它的非线性演化方程.这两种信息(熵)演化方程一致表明:统计信息(熵)密度 随时间的变化率是由其在坐标空间(和态变量空间)的漂移、扩散和减损(产生)三者引起 的.由此方程出发,给出了统计信息减损率和统计熵产生率的简明公式、漂移信息流和扩散 信息流的表达式,证明了非平衡系统内的统计信息减损(或增加)率等于它的统计熵产生( 或减少)率、信息扩散与信息减损同时
关键词:
统计信息(熵)演化方程
统计信息减损率
统计熵产 生率
信息(熵)流
信息(熵)扩散
动态互信息 相似文献