A NEW ONE—DIMENSIONAL CHAOTIC MAP WITH INFINITE COLLAPSES

This letter presents a new one-dimensional chaotic map with infinite collapses. Theoretical analyses show that the map has complicated dynamical behavior and ideal distribution. The map can be applied in chaotic spreading spectrum communication and chaotic cipher.     

使用遗传算法进行微波非线性电路包络仿真

介绍用于分析任意调制信号激励的微波非线性电路包络仿真技术,相应给出了线性器件的伴随模型,并将该方法发展为分析多载波调制信号激励的强非线性电路。此外,本文给出了一种求解非线性谐波平衡方程组或交调波平衡方程组的非数值方法———基于十进制编码的混沌遗传算法(DCGA),融合设计了相应的交叉和变异操作,并将混沌过程引入其中以避免陷入早熟状态,可有效地产生更优解,并加速种群的收敛。最后,给出了运用这种方法的两个计算实例。     

一种实用的信号类型诊断方法及其在船舶辐射噪声中的应用

对一种基于ＫＳＷ理论的信号类型诊断方法进行了深入的研究,并将此方法用于船舶辐射噪声的分析中,为进一步了解船舶辐射噪声的特性提供了新的途径。另外,还发现,本方法不仅可以准确地诊断信号的类型,而且可以用来检验信号重构的质量．     

A random sequence generator based on chaotic circuits

In this paper, a random sequence generator based on chaotic circuits is presented. Fundamental principle and experimental circuit have been carried out in case of Chua's circuit. The statistical results are in good agreement with probability characteristics of random sequence.     

基于预测和动态阈值的流量异常检测机制研究

针对流量异常检测中的基线和阈值难以精确刻画的问题,提出了一种基于预测和动态阈值的异常检测机制.通过构造混沌支持向量机预测模型对流量基线值进行确定;采用假设检验的异常检验方法,利用一天中各时段对应训练集拟合残差符合正态分布的特点构造符合t分布的随机变量,进而计算各时段预测残差的置信区间来动态地确定网络流量的阈值.实验结果表明,预测模型具有很高的预测精度,该异常检测机制具有一定的可行性.     

混沌灰狼优化算法训练多层感知器

灰狼优化算法(GWO)是一种新的基于灰狼捕食行为的元启发式算法,被证明是一种具有高水平的探索和开发能力的算法。但是存在开发和探索不平衡的问题,以至于其优化性能并不理想。该文将混沌理论引入GWO中,用于平衡GWO的探索和开发,提出一种改进的混沌灰狼优化算法(CGWO),并应用于多层感知器(MLPs)的训练。首先,基于Cubic混沌理论对GWO的位置更新公式进行改进,以增加个体的多样性,增大跳出局部最优的概率和对解空间进行深入的搜索;其次,设计一种非线性收敛因子,用于协调和平衡CGWO算法在不同迭代进化时期的探索和开发能力;最后,将CGWO算法作为MLPs的训练器,用于对3个复杂分类问题进行分类实验。结果表明：CGWO在分类准确率,避免陷入局部最优,全局收敛速度和鲁棒性方面相较于其他对比算法均具有较好的性能。

     

具有时延的神经元模型耦合系统的混沌同步

该文研究了一个由有混沌现象的具有时延的简单神经元模型构成的耦台系统的混沌同步,具有时延的神经元模型混沌系统,对时延的初始值具有敏感性,对于任意激活函数,用解析分析方法得到了耦合系统达到强同步的一般化条件。     

基于混沌保密的无线语音通信系统

针对无线语音通信易被监听等特点,设计了一种基于混沌保密的无线语音通信系统.该系统中以AT89C51单片机和射频收发器为核心,采用改进的混沌算法.该文分析了系统的工作原理和工作过程并给出了硬件电路图及固件流程图,着重说明了改进的混沌算法在单片机上的实现方法.最后,在单片机上成功进行了混沌保密的无线语音通信实验并取得了令人满意的结果.     

A novel hybrid image encryption–compression scheme by combining chaos theory and number theory

Compression and encryption are often performed together for image sharing and/or storage. The order in which the two operations are carried out affects the overall efficiency of digital image services. For example, the encrypted data has less or no compressibility. On the other hand, it is challenging to ensure reasonable security without downgrading the compression performance. Therefore, incorporating one requirement into another is an interesting approach. In this study, we propose a novel hybrid image encryption and compression scheme that allows compression in the encryption domain. The encryption is based on Chaos theory and is carried out in two steps, i.e., permutation and substitution. The lossless compression is performed on the shuffled image and then the compressed bitstream is grouped into 8-bit elements for substitution stage. The lossless nature of the proposed method makes it suitable for medical image compression and encryption applications. The experimental results shows that the proposed method achieves the necessary level of security and preserves the compression efficiency of a lossless algorithm. In addition, to improve the performance of the entropy encoder of the compression algorithm, we propose a data-to-symbol mapping method based on number theory to represent adjacent pixel values as a block. With such representation, the compression saving is improved on average from 5.76% to 15.45% for UCID dataset.     

混沌保密通信系统中平凡密钥现象的探讨

论文从混沌动力系统的基本定义和性质出发,在对Logistic、Chebyshev等几种典型混沌动力系统的“平凡密钥”和“拟平凡密钥”现象进行深入分析的基础上,给出了该现象存在的广义解释,同时提出了几种克服该现象的实用解决方案,实验结果证明这些方案实时有效,实用性强。