贝叶斯网络参数学习中的连续变量离散化方法

首先从离散方案对推理功能的影响出发,提出将条件信息熵作为评判离散方案好坏的标准;其次从降低问题求解的复杂度出发,提出将贝叶斯网络划分为多个极小简单子网分别进行离散化;最后,依据离散化问题与路径规划问题的相似性,设计了一套利用蚁群算法进行问题求解的方法。实验表明,采用所提方法进行贝叶斯网络连续变量离散化,能很好地将连续变量的取值空间进行分类,从而达到良好的推理效果。     

具有连续变量的非线性脉冲时滞差分方程的振动性

考虑一类具有连续变量的非线性脉冲差分方程,通过利用研究无脉冲条件的具有连续变量的差分方程的思想方法,得出了其所有解振动的充分条件,推广和改进了已有的结果。     

A novel evolutionary algorithm for global numerical optimization with continuous variables

Evolutionary algorithms （EAs） are a class of general optimization algorithms which are applicable to functions that are multimodal, non-differentiable, or even discontinuous. In this paper, a novel evolutionary algorithm is proposed to solve global numerical optimiza- tion with continuous variables. In order to make the algorithm more robust, the initial population is generated by combining determinate factors with random ones, and a decent scale function is designed to tailor the crossover operator so that it can not only find the decent direction quickly but also keep scanning evenly in the whole feasible space. In addition, to improve the performance of the algorithm, a mutation operator which increases the convergence-rate and ensures the convergence of the proposed algorithm is designed. Then, the global convergence of the presented algorithm is proved in detail. Finally, the presented algorithm is executed to solve 24 benchmark problems, and the results show that the convergence-rate of the proposed algorithm is much faster than that of the compared algorithms.     

具连续变量的二阶非线性中立型时滞差分方程的有界振动性

研究一类具有连续变量的二阶非线性中立型时滞差分方程,利用Banach空间的压缩映象原理和一些分析技巧,得到了这类方程存在有界的最终正解的判别准则,同时得出了该类方程振动的几个判别依据.     

具连续变量脉冲时滞差分方程的振动性

利用构造辅助方程的方法,建立了无脉冲的具连续变量时滞差分方程与有脉冲具连续变量时滞差分方程在振动性上的等价性,然后利用反证法、构造序列法和积分中值定理等方法,研究了无脉冲的具连续变量时滞差分方程的振动性,得到了方程所有解振动的两个充分性条件,从而得到了具有连续变量脉冲时滞差分方程的所有解振动的两个充分性条件。     

具连续变量非线性差分方程非振动解在脉冲扰动下的保持性

考虑一类具连续变量的非线性时滞差分方程,证明了在一定条件下,其非振动解的存在性在脉冲扰动下仍保持,推广了文献[数学物理学报,2006,26A （4）：595-600]中的相关结论.     

具连续变量的中立型差分方程的振动性

讨论具有连续变量的中立型差分方程,建立了该方程振动的若干充分条件。     

具有连续变量的二阶非线性中立型差分方程的振动性

本文用分析的方法研究了一类具有连续变量的多时滞二阶非线性中立型差分方程解的振动性,得出了该类方程解振动的几个充分条件.     

具连续变量的阻尼中立型差分方程的振动性

针对一类具有连续变量的二阶阻尼中立型差分方程的振动性问题,利用适当的不等式、反证法和广义Riccati变换,取得了该类方程解以及有界解振动的几个充分条件.该成果在生物学、经济学、人口学、物理学以及控制论等领域有广泛的应用.     

Applying Gaussian quantum discord to quantum key distribution

In this paper, we theoretically prove that the Gaussian quantum discord state of optical field can be used to complete continuous variable （CV） quantum key distri- bution （QKD）. The calculation shows that secret key can be distilled with a Gaussian quantum discord state against entangling cloner attack. Secret key rate is increased with the increasing of quantum discord for CV QKD with the Gaussian quantum discord state. Although the calculated results point out that secret key rate using the Gaussian quantum discord state is lower than that using squeezed state and coherent state at the same energy level, we demonstrate that the Gaussian quantum discord, which only involving quantum correlation without the existence of entanglement, may provide a new resource for realizing CV QKD.