作者：陈芝红

学位名称：硕士

出处：北京理工大学 2017

作者：韩希武

学位名称：硕士

出处：北京理工大学数学与统计学院 2016

关键词：四元数；水印；线性正则变换；鲁棒性

摘要：基于把水印分散于变换域上的水印算法的性能强烈依赖于核函数. 线性正则变换是傅里叶变换、分数阶傅里叶变换、Fresnel变换和缩放变换的一种推广. 线性正则变换是信号处理领域当中的一种重要工具. 二维线性正则变换是线性正则变换的进一步推广. 在本文中, 我们将二维线性正则变换推广到四元数域上, 将它命 ...

作者：张树邦

学位名称：硕士

出处：北京理工大学

作者：Li, Tongzhu;Ma, Xiang;Wang, Changping;Wang, Peng （¹Department of Mathematics, Beijing Institute of Technology, Beijing, China;²LMAM, School of Mathematical Sciences, Peking University, Beijing, China;³College of Mathematics and Computer Science, Fujian Normal University, Fuzhou, China）

出处：arXiv 2022

摘要：Let M(Sn+1) denote the Möbius transformation group of the (n+1)-dimensional sphere Sn+1. A hypersurface x: Mn → Sn+1 is called a Möbius homogeneous hy ...

作者：Yayun Chen;Tongzhu Li （¹Department of Mathematics, Beijing Institute of Technology, Beijing 100081, China）

出处：Mathematics 2023

关键词：generic conformally flat hypersurface;Möbius metric;Möbius form;Möbius curvature

摘要：A conformally flat hypersurface f:M3→R4 in the four-dimensional Euclidean space R4 is said to be generic if the hypersurface has three distinct princi ...

作者：Xie, Zhenxiao¹;Li, Tongzhu²;Ma, Xiang³;Wang, Changping⁴; （¹Department of Mathematics, China University of Mining and Technology (Beijing), Beijing, 100083, China;²Department of Mathematics, Beijing Institute of Technology, Beijing, 100081, China;³School of Mathematical Sciences, Peking University, Beijing, 100871, China;⁴School of Mathematics and Computer Science, FJKLMAA, Fujian Normal University, Fuzhou, 350108, China）

出处：Advances in Mathematics 2021

摘要：In real space forms, any submanifold must satisfy the so-called DDVV inequality which relates the scalar curvature, the mean curvature, and the scalar ...

作者：姬秀，李同柱 （北京理工大学数学与统计学院；北京理工大学数学与统计学院）

出处：数学学报 2021

关键词：共形度量；共形第二基本形式；共形拟Blaschke张量

摘要：设f:M^m→R^m+1₁是无脐点类空超曲面,则在M^m上可以定义四个基本的共形不变量:共形度量g,共形1-形式C,共形第二基本形式B,共形Blaschke张量A.如果存在光滑函数λ和常数μ,使得A+μB=λg,则称M ...