We investigate the Furi-Martelli-Vignoli spectrum and the Feng spectrum of continuous nonlinear block operator matrices,and mainly describe the relationship between the Furi-Martelli-Vignoli spectrum(compared to the F...We investigate the Furi-Martelli-Vignoli spectrum and the Feng spectrum of continuous nonlinear block operator matrices,and mainly describe the relationship between the Furi-Martelli-Vignoli spectrum(compared to the Feng spectrum)of the whole operator matrix and that of its entries.In addition,the connection between the Furi-Martelli-Vignoli spectrum of the whole operator matrix and that of its Schur complement is presented by means of Schur decomposition.展开更多
In this paper,some refinements of norm equalities and inequalities of combination of two orthogonal projections are established.We use certain norm inequalities for positive contraction operator to establish norm ineq...In this paper,some refinements of norm equalities and inequalities of combination of two orthogonal projections are established.We use certain norm inequalities for positive contraction operator to establish norm inequalities for combination of orthogonal projections on a Hilbert space.Furthermore,we give necessary and sufficient conditions under which the norm of the above combination of o`rthogonal projections attains its optimal value.展开更多
This paper investigates the numerical solution of two-dimensional nonlinear stochastic Itô-Volterra integral equations based on block pulse functions. The nonlinear stochastic integral equation is transformed...This paper investigates the numerical solution of two-dimensional nonlinear stochastic Itô-Volterra integral equations based on block pulse functions. The nonlinear stochastic integral equation is transformed into a set of algebraic equations by operational matrix of block pulse functions. Then, we give error analysis and prove that the rate of convergence of this method is efficient. Lastly, a numerical example is given to confirm the method.展开更多
为提高哈希算法的感知性与鲁棒性,提出一种基于块截断编码与邻域空间LBP算子的鲁棒图像哈希算法。将预处理图像分割为非重叠子块,结合奇异值分解SVD(singular value decomposition),获取二次图像,引入块截断编码机制,输出其高、低电平...为提高哈希算法的感知性与鲁棒性,提出一种基于块截断编码与邻域空间LBP算子的鲁棒图像哈希算法。将预处理图像分割为非重叠子块,结合奇异值分解SVD(singular value decomposition),获取二次图像,引入块截断编码机制,输出其高、低电平矩和二进制位图;基于LBP(local binary pattern)算子,设计邻域空间LBP模式,获取位图的特征矩阵;构造量化函数,得到高、低电平矩阵对应的紧凑二值序列,利用主成分分析处理特征矩阵,输出二值序列,组合这些二值序列,获取图像哈希。根据Hamming距离,对图像真伪进行认证。实验数据表明,与当前哈希算法相比,所提哈希算法具有更好的抗碰撞性能与感知鲁棒。展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11561048 and 11761029)the Natural Science Foundation of Inner Mongolia,China(Grant Nos.2019MS01019 and 2020ZD01)。
文摘We investigate the Furi-Martelli-Vignoli spectrum and the Feng spectrum of continuous nonlinear block operator matrices,and mainly describe the relationship between the Furi-Martelli-Vignoli spectrum(compared to the Feng spectrum)of the whole operator matrix and that of its entries.In addition,the connection between the Furi-Martelli-Vignoli spectrum of the whole operator matrix and that of its Schur complement is presented by means of Schur decomposition.
文摘In this paper,some refinements of norm equalities and inequalities of combination of two orthogonal projections are established.We use certain norm inequalities for positive contraction operator to establish norm inequalities for combination of orthogonal projections on a Hilbert space.Furthermore,we give necessary and sufficient conditions under which the norm of the above combination of o`rthogonal projections attains its optimal value.
基金NSF Grants 11471105 of China, NSF Grants 2016CFB526 of Hubei Province, Innovation Team of the Educational Department of Hubei Province T201412, and Innovation Items of Hubei Normal University 2018032 and 2018105
文摘This paper investigates the numerical solution of two-dimensional nonlinear stochastic Itô-Volterra integral equations based on block pulse functions. The nonlinear stochastic integral equation is transformed into a set of algebraic equations by operational matrix of block pulse functions. Then, we give error analysis and prove that the rate of convergence of this method is efficient. Lastly, a numerical example is given to confirm the method.
文摘为提高哈希算法的感知性与鲁棒性,提出一种基于块截断编码与邻域空间LBP算子的鲁棒图像哈希算法。将预处理图像分割为非重叠子块,结合奇异值分解SVD(singular value decomposition),获取二次图像,引入块截断编码机制,输出其高、低电平矩和二进制位图;基于LBP(local binary pattern)算子,设计邻域空间LBP模式,获取位图的特征矩阵;构造量化函数,得到高、低电平矩阵对应的紧凑二值序列,利用主成分分析处理特征矩阵,输出二值序列,组合这些二值序列,获取图像哈希。根据Hamming距离,对图像真伪进行认证。实验数据表明,与当前哈希算法相比,所提哈希算法具有更好的抗碰撞性能与感知鲁棒。
