The segmentation effect of Tsallis entropy method is superior to that of Shannon entropy method, and the computation speed of two-dimensional Shannon cross entropy method can be further improved by optimization. The e...The segmentation effect of Tsallis entropy method is superior to that of Shannon entropy method, and the computation speed of two-dimensional Shannon cross entropy method can be further improved by optimization. The existing two-dimensional Tsallis cross entropy method is not the strict two-dimensional extension. Thus two new methods of image thresholding using two-dimensional Tsallis cross entropy based on either Chaotic Particle Swarm Optimization (CPSO) or decomposition are proposed. The former uses CPSO to find the optimal threshold. The recursive algorithm is adopted to avoid the repetitive computation of fitness function in iterative procedure. The computing speed is improved greatly. The latter converts the two-dimensional computation into two one-dimensional spaces, which makes the computational complexity further reduced from O(L2) to O(L). The experimental results show that, compared with the proposed recently two-dimensional Shannon or Tsallis cross entropy method, the two new methods can achieve superior segmentation results and reduce running time greatly.展开更多
针对从低压电网的总剩余电流中提取触电支路电流的难题,利用混沌系统对初始条件敏感及对噪声免疫的特性,提出基于椭圆域分割法的触电电流混沌检测方法。在混沌系统的二维相轨迹图中引入椭圆域分割线,通过其输出的高低电平表示相轨迹穿...针对从低压电网的总剩余电流中提取触电支路电流的难题,利用混沌系统对初始条件敏感及对噪声免疫的特性,提出基于椭圆域分割法的触电电流混沌检测方法。在混沌系统的二维相轨迹图中引入椭圆域分割线,通过其输出的高低电平表示相轨迹穿越椭圆域分割线的状态,根据输出的低电平次数定量判别混沌系统所处的状态,从而实现触电信号的提取。利用待测信号相位和系统状态存在的对应关系,确定待测信号初相位并修正,以提高该方法的检测精度。针对195组触电信号检测结果表明,相位修正前、后的检测误差从32.5%减小到4.1%,检测信噪比由[0,-50 d B]增加到[0,-63 d B],所提议的方法能够从包含强噪声的总剩余电流中检测出触电电流,为新型剩余电流保护装置的开发提供一定的参考价值。展开更多
为了解决彩色图像多阈值分割中计算时间长、分割精度低的问题,在电磁场优化算法(Electromagnetic Field Optimization,EFO)的基础上引入一种混沌策略用于算法初始化中,提出混沌电磁场优化算法(Chaotic Electromagnetic Field Optimizati...为了解决彩色图像多阈值分割中计算时间长、分割精度低的问题,在电磁场优化算法(Electromagnetic Field Optimization,EFO)的基础上引入一种混沌策略用于算法初始化中,提出混沌电磁场优化算法(Chaotic Electromagnetic Field Optimization,CEFO)对图像的最佳阈值向量进行搜索。将其与另外5种优化算法进行对比,采用PSNR、MSSIM和FSIM 3个图像质量评价指标和算法运行时间(CPU Time)对6种分割算法进行分析比较。结果表明,CEFO具有收敛速度快、分割精度高的优势,能够胜任多阈值彩色图像分割的工程任务。展开更多
判别Duffing混沌系统所处的状态是采用Duffing混沌振子进行微弱周期信号检测的关键问题.本文针对系统在混沌和大周期两种状态相图的明显区别,提出了一种基于相图分割的系统状态判定方法.该方法首先在相图中做一简单闭合区域,进而通过统...判别Duffing混沌系统所处的状态是采用Duffing混沌振子进行微弱周期信号检测的关键问题.本文针对系统在混沌和大周期两种状态相图的明显区别,提出了一种基于相图分割的系统状态判定方法.该方法首先在相图中做一简单闭合区域,进而通过统计相轨迹点处于区域外的数量来识别系统的状态.给出了实现该方法的主要步骤,并从微弱信号检测成功率和运算复杂度的角度进行了分析.实验结果表明该方法可用于30 d B信噪比下弱正弦信号的检测,并且硬件实现简单.展开更多
基金supported by National Natural Science Foundation of China under Grant No.60872065Open Foundation of State Key Laboratory for Novel Software Technology at Nanjing University under Grant No.KFKT2010B17
文摘The segmentation effect of Tsallis entropy method is superior to that of Shannon entropy method, and the computation speed of two-dimensional Shannon cross entropy method can be further improved by optimization. The existing two-dimensional Tsallis cross entropy method is not the strict two-dimensional extension. Thus two new methods of image thresholding using two-dimensional Tsallis cross entropy based on either Chaotic Particle Swarm Optimization (CPSO) or decomposition are proposed. The former uses CPSO to find the optimal threshold. The recursive algorithm is adopted to avoid the repetitive computation of fitness function in iterative procedure. The computing speed is improved greatly. The latter converts the two-dimensional computation into two one-dimensional spaces, which makes the computational complexity further reduced from O(L2) to O(L). The experimental results show that, compared with the proposed recently two-dimensional Shannon or Tsallis cross entropy method, the two new methods can achieve superior segmentation results and reduce running time greatly.
文摘针对从低压电网的总剩余电流中提取触电支路电流的难题,利用混沌系统对初始条件敏感及对噪声免疫的特性,提出基于椭圆域分割法的触电电流混沌检测方法。在混沌系统的二维相轨迹图中引入椭圆域分割线,通过其输出的高低电平表示相轨迹穿越椭圆域分割线的状态,根据输出的低电平次数定量判别混沌系统所处的状态,从而实现触电信号的提取。利用待测信号相位和系统状态存在的对应关系,确定待测信号初相位并修正,以提高该方法的检测精度。针对195组触电信号检测结果表明,相位修正前、后的检测误差从32.5%减小到4.1%,检测信噪比由[0,-50 d B]增加到[0,-63 d B],所提议的方法能够从包含强噪声的总剩余电流中检测出触电电流,为新型剩余电流保护装置的开发提供一定的参考价值。
文摘为了解决彩色图像多阈值分割中计算时间长、分割精度低的问题,在电磁场优化算法(Electromagnetic Field Optimization,EFO)的基础上引入一种混沌策略用于算法初始化中,提出混沌电磁场优化算法(Chaotic Electromagnetic Field Optimization,CEFO)对图像的最佳阈值向量进行搜索。将其与另外5种优化算法进行对比,采用PSNR、MSSIM和FSIM 3个图像质量评价指标和算法运行时间(CPU Time)对6种分割算法进行分析比较。结果表明,CEFO具有收敛速度快、分割精度高的优势,能够胜任多阈值彩色图像分割的工程任务。
文摘判别Duffing混沌系统所处的状态是采用Duffing混沌振子进行微弱周期信号检测的关键问题.本文针对系统在混沌和大周期两种状态相图的明显区别,提出了一种基于相图分割的系统状态判定方法.该方法首先在相图中做一简单闭合区域,进而通过统计相轨迹点处于区域外的数量来识别系统的状态.给出了实现该方法的主要步骤,并从微弱信号检测成功率和运算复杂度的角度进行了分析.实验结果表明该方法可用于30 d B信噪比下弱正弦信号的检测,并且硬件实现简单.
