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利用Arnold对称性变换的图像信息隐藏算法 被引量:19
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作者 倪蓉蓉 阮秋琦 《北方交通大学学报》 CSCD 北大核心 2002年第2期25-28,共4页
提出了一种利用Arnold对称性变换的图像信息隐藏算法 .待隐藏的秘密信息以及公开的承载信息均为灰度级静止图像 .首先使用图像置乱技术将秘图变换成无意义的图像 ,同时用一个数值控制置乱的次数 ,并在嵌入和提取时作为密钥 .在此基础上 ... 提出了一种利用Arnold对称性变换的图像信息隐藏算法 .待隐藏的秘密信息以及公开的承载信息均为灰度级静止图像 .首先使用图像置乱技术将秘图变换成无意义的图像 ,同时用一个数值控制置乱的次数 ,并在嵌入和提取时作为密钥 .在此基础上 ,将密图嵌入到承载图像的DCT域系数中 .该算法实现的隐藏图像透明性好 。 展开更多
关键词 Arnold对称性变换 图像信息隐藏算法 离散余弦变换 密钥
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M序列的对称性变换及对称群
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作者 刘义春 尹克震 《杭州电子科技大学学报(自然科学版)》 2009年第4期9-13,共5页
n级M序列是由n级非线性回馈移位寄存器产生的周期为2n的二元序列,也称为de Bruijn序列。该文将讨论M序列的对称性变换,提出了一类新的对称性变换——"与/或"逻辑对称性变换,并研究了基于对称性变换的对称群。
关键词 伪随机序列 全长移位寄存器序列 对称性变换 对称
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关于在CPT对称引用新的对称变换H
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作者 张树强 《长春师范学院学报》 2000年第2期75-77,共3页
粒子在 CPT变换下不守恒的表现 ,我们引入一个 H变换后能使粒子有
关键词 对称性 守恒 粒子 对称性变换 H CPT 中微子 CPTH
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对称性与守恒律
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作者 蒋学华 《济宁师范专科学校学报》 2000年第6期16-17,共2页
阐述了对称性和守恒律的关系 ,以及对称性和对称性破缺产生的根源 。
关键词 守恒律 对称性 对称性破缺 物理学 形象对称性 抽象对称性 变换对称性 不可观测量
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第一激发态HOOO裂解反应的理论研究 被引量:1
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作者 杨静 李前树 《分子科学学报》 CAS CSCD 2007年第1期73-75,共3页
利用量子化学方法对第一激发态HOOO的裂解反应进行了理论研究.所有驻点(反应物、产物和过渡态)的几何结构优化和振动分析都是在CASSCF/6-31+G(d,p)理论水平下进行的.反应路径上的选择点及驻点都在CASPT2/6-31+G(d,p)//CASSCF(19,13)/6-3... 利用量子化学方法对第一激发态HOOO的裂解反应进行了理论研究.所有驻点(反应物、产物和过渡态)的几何结构优化和振动分析都是在CASSCF/6-31+G(d,p)理论水平下进行的.反应路径上的选择点及驻点都在CASPT2/6-31+G(d,p)//CASSCF(19,13)/6-31+G(d,p)和MRCI/6-31+G(d,p)//CASSCF(19,13)/6-31+G(d,p)理论水平下进行单点能量校正.CASSCF,CASPT2和MRCI水平的理论计算结果显示,第一激发态HOOO的裂解反应包含一个对称性变化的过程.它首先通过了一个Cs对称性的过渡态,然后逐渐变化为线性结构,最终生成产物O2(3Σg-)和OH(2Π). 展开更多
关键词 HOOO 从头算 对称性变换
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群论中的几何直观教学法
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作者 郭丽 杨月婷 《数学学习与研究》 2012年第23期17-17,共1页
讨论了几何直观教学在近世代数教学的作用和重要性,从概念的引入、定理的几何意义及应用等方面阐述了加强几何直观教学的意义,并通过例子加以说明.在群论教学中运用几何直观教学法不仅有助于利用形象思维理解和运用抽象的概念和结论,同... 讨论了几何直观教学在近世代数教学的作用和重要性,从概念的引入、定理的几何意义及应用等方面阐述了加强几何直观教学的意义,并通过例子加以说明.在群论教学中运用几何直观教学法不仅有助于利用形象思维理解和运用抽象的概念和结论,同时也突出了抽象的概念和结论在处理复杂几何图形时的作用.由此可以激发学生学习近世代数的兴趣,培养学生应用近世代数知识的能力. 展开更多
关键词 几何直观 对称性变换 群作用
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GOMP改进算法在信道估计中的应用 被引量:4
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作者 任晓奎 张芷宁 《计算机应用与软件》 北大核心 2018年第3期289-293,298,共6页
广义正交匹配追踪GOMP(Generalized Orthogonal Matching Pursuit)算法作为压缩感知理论中的重要组成部分,在信道估计领域早有应用。但由于无法解决信道稀疏度的获取问题,限制了这一算法的发展。针对这一问题,提出一种通过变步长实现稀... 广义正交匹配追踪GOMP(Generalized Orthogonal Matching Pursuit)算法作为压缩感知理论中的重要组成部分,在信道估计领域早有应用。但由于无法解决信道稀疏度的获取问题,限制了这一算法的发展。针对这一问题,提出一种通过变步长实现稀疏自适应匹配的改进算法,并利用傅里叶变换的共轭对称性在选择原子方面加以完善,从而提高了算法的精度和效率,增强了该算法在实际信道估计中的可行性。 展开更多
关键词 压缩感知 信道估计 广义正交匹配追踪 傅里叶变换的共轭对称性
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Finite Symmetry Transformation Groups and Some Exact Solutions to(2+1)-Dimensional Cubic Nonlinear Schrdinger Equantion 被引量:3
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作者 LI Biao LI Yu-Qi CHEN Yong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第5期773-776,共4页
Making use of the direct method proposed by Lou et al. and symbolic computation, finite symmetry transformation groups for a (2+ l)-dimensional cubic nonlinear Schrodinger (NLS) equation and its corresponding cyl... Making use of the direct method proposed by Lou et al. and symbolic computation, finite symmetry transformation groups for a (2+ l)-dimensional cubic nonlinear Schrodinger (NLS) equation and its corresponding cylindrical NLS equations are presented. Nine related linear independent infinitesimal generators can be obtained from the finite symmetry transformation groups by restricting the arbitrary constants in infinitesimal forms. Some exact solutions are derived from a simple travelling wave solution. 展开更多
关键词 symmetry groups cubic NLS equation exact solution
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Gauge Symmetry and Transverse Symmetry Transformations in Gauge Theories
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作者 HE Han-Xin 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第8期292-294,共3页
The transverse symmetry transformations associated with the normal symmetry transformations are proposedto build the transverse constraints on the basic vertices in gauge theories.I show that,while the BRST symmetryin... The transverse symmetry transformations associated with the normal symmetry transformations are proposedto build the transverse constraints on the basic vertices in gauge theories.I show that,while the BRST symmetryin non-Abelian gauge theory QCD (Quantum Chromodynamics) leads to the Slavnov-Taylor identity for the quark-gluonvertex which constrains the longitudinal part of the vertex,the transverse symmetry transformation associated with theBRST symmetry enables to derive the transverse Slavnov-Taylor identity for the quark-gluon vertex,which constrainsthe transverse part of the quark-gluon vertex from the gauge symmetry of QCD. 展开更多
关键词 transverse symmetry transformation transverse Slavnov-Taylor identity quark-gluon vertex
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Conformal Invariance and a New Type of Conserved Quantities of Mechanical Systems with Variable Mass in Phase Space
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作者 ZHANG Ming-Jiang FANG Jian-Hui LIN Peng LU Kai PANG Ting 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第10期561-564,共4页
Conformal invariance and a new type of conserved quantities of mechanical systems with variable mass in phase space are studied. Firstly, the definition and determining equation of conformal invariance are presented. ... Conformal invariance and a new type of conserved quantities of mechanical systems with variable mass in phase space are studied. Firstly, the definition and determining equation of conformal invariance are presented. The relationship between the conformal invariance and the Lie symmetry is given, and the necessary and sufficient condition that the conformal invarianee would be the Lie symmetry under the infinitesimal transformations is provided. Secondly, a new type of conserved quantities of the conformal invariance are obtained by using the Lie symmetry of the system. Lastly, an example is given to illustrate the application of the results. 展开更多
关键词 conformal invariance conserved quantity variable mass system phhse space
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Symmetries of Energy-Momentum Tensor: Some Basic Facts
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作者 M.Sharif TariqIsmaeel 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第5期829-834,共6页
It has been pointed out by Hall et al. [Gen. Rel. Gray. 28 (1996) 299.] that matter collineations can be defined by using three different methods. But there arises the question whether one studies matter collineati... It has been pointed out by Hall et al. [Gen. Rel. Gray. 28 (1996) 299.] that matter collineations can be defined by using three different methods. But there arises the question whether one studies matter collineations by using LεTab=0, or LεT^ab = 0 or LεT^b a=0. These alternative conditions are, of. course, not generally equivalent. This problem has been explored by applying these three definitions to general static spherically symmetric spacetimes. We compare the results with each definition. 展开更多
关键词 SYMMETRIES energy-momentum tensor
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Lie Reduction and Conditional Symmetries of Some Variable Coefficient Nonlinear Wave Equations
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作者 黄定江 周水庚 +1 位作者 梅建琴 张鸿庆 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第1期1-5,共5页
Lie symmetry reduction of some truly "variable coefficient" wave equations which are singled out from a class of (1 + 1)-dimensional variable coefficient nonlinear wave equations with respect to one and two-dimen... Lie symmetry reduction of some truly "variable coefficient" wave equations which are singled out from a class of (1 + 1)-dimensional variable coefficient nonlinear wave equations with respect to one and two-dimensional algebras is carried out. Some classes of exact solutions of the investigated equations are found by means of both the reductions and some modern techniques such as additional equivalent transformations and hidden symmetries and so on. Conditional symmetries are also discussed. 展开更多
关键词 symmetry reduction conditional symmetry exact solutions variable-coefficient nonlinear wave equations
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Symmetry theories of Hamiltonian systems with fractional derivatives 被引量:25
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作者 ZHOU Sha FU Hao FU JingLi 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2011年第10期1847-1853,共7页
The Noether and Lie symmetries as well as the conserved quantities of Hamiltonian system with fractional derivatives are es-tablished. The definitions and criteria for the fractional symmetrical transformations and qu... The Noether and Lie symmetries as well as the conserved quantities of Hamiltonian system with fractional derivatives are es-tablished. The definitions and criteria for the fractional symmetrical transformations and quasi-symmetrical transformations inthe Noether sense of Hamiltonian system are first discussed. Then, using the invariance of Hamiltonian action under the infini-tesimal transformations with respect to time, generalized coordinates and generalized momentums, the fractional Noethertheorem of the system is obtained. Further, the Lie symmetry and conserved quantity of the system are acquired. Two exam-ples are presented to illustrate the application of the results. 展开更多
关键词 SYMMETRY conserved quantity Hamiltonian system fractional derivative
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Symmetry Transformation and New Exact Multiple Kink and Singular Kink Solutions for (2+1)-Dimensional Nonlinear Models Generated by the Jaulent-Miodek Hierarchy 被引量:2
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作者 马红彩 秦振云 郑爱平 《Communications in Theoretical Physics》 SCIE CAS CSCD 2013年第2期141-145,共5页
In this paper, we consider a system of (2+2)-dimensional nonlinear models by using CK direct method and Hereman-Nuseir method generated by the Janlent-Miodek Hierarchy. We construct some new multiple kink and singu... In this paper, we consider a system of (2+2)-dimensional nonlinear models by using CK direct method and Hereman-Nuseir method generated by the Janlent-Miodek Hierarchy. We construct some new multiple kink and singular kink solutions of (2+1)-Dimensional Nonlinear Models with the aid of symbolic computation. 展开更多
关键词 symmetry multiple kink solutions Jaulent-Miodek hierarchy CK direct method
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Exact Solutions,Symmetry Reductions,Painlevé Test and Bcklund Transformations of A Coupled KdV Equation 被引量:1
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作者 徐敏慧 贾曼 《Communications in Theoretical Physics》 SCIE CAS CSCD 2017年第10期417-424,共8页
A coupled KdV equation is studied in this manuscript. The exact solutions, such as the periodic wave solutions and solitary wave solutions by means of the deformation and mapping approach from the solutions of the non... A coupled KdV equation is studied in this manuscript. The exact solutions, such as the periodic wave solutions and solitary wave solutions by means of the deformation and mapping approach from the solutions of the nonlinear φ4 model are given. Using the symmetry theory, the Lie point symmetries and symmetry reductions of the coupled KdV equation are presented. The results show that the coupled KdV equation possesses infinitely many symmetries and may be considered as an integrable system. Also, the Palnleve test shows the coupled KdV equation possesses Palnleve property. The Backlund transformations of the coupled KdV equation related to Palnleve property and residual symmetry are shown. 展开更多
关键词 a coupled KdV equation exact solutions symmetries and symmetry reductions Painleve test Backlund transformations
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Entire solution in an ignition nonlocal dispersal equation:Asymmetric kernel 被引量:3
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作者 ZHANG Li LI WanTong WANG ZhiCheng 《Science China Mathematics》 SCIE CSCD 2017年第10期1791-1804,共14页
This paper mainly focuses on the front-like entire solution of a classical nonlocal dispersal equation with ignition nonlinearity. Especially, the dispersal kernel function J may not be symmetric here. The asymmetry o... This paper mainly focuses on the front-like entire solution of a classical nonlocal dispersal equation with ignition nonlinearity. Especially, the dispersal kernel function J may not be symmetric here. The asymmetry of J has a great influence on the profile of the traveling waves and the sign of the wave speeds, which further makes the properties of the entire solution more diverse. We first investigate the asymptotic behavior of the traveling wave solutions since it plays an essential role in obtaining the front-like entire solution. Due to the impact of f′(0) = 0, we can no longer use the common method which mainly depends on Ikehara theorem and bilateral Laplace transform to study the asymptotic rates of the nondecreasing traveling wave and the nonincreasing one tending to 0, respectively, so we adopt another method to investigate them. Afterwards, we establish a new entire solution and obtain its qualitative properties by constructing proper supersolution and subsolution and by classifying the sign and size of the wave speeds. 展开更多
关键词 entire solution asymptotic behavior traveling wave solutions nonlocal dispersal ASYMMETRIC IGNITION
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On the Lie Algebras, Generalized Symmetries and Darboux Transformations of the Fifth-Order Evolution Equations in Shallow Water 被引量:2
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作者 Shoufu TIAN Yufeng ZHANG +1 位作者 Binlu FENG Hongqing ZHANG 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2015年第4期543-560,共18页
By considering the one-dimensional model for describing long, small amplitude waves in shallow water, a generalized fifth-order evolution equation named the Olver water wave (OWW) equation is investigated by virtue ... By considering the one-dimensional model for describing long, small amplitude waves in shallow water, a generalized fifth-order evolution equation named the Olver water wave (OWW) equation is investigated by virtue of some new pseudo-potential systems. By introducing the corresponding pseudo-potential systems, the authors systematically construct some generalized symmetries that consider some new smooth functions {Xiβ}β=1,2…,N^i=1,2…,n depending on a finite number of partial derivatives of the nonlocal variables vβ and a restriction i,α,β∑( ξi/ vβ)^2+( ηα/ vβ)^2≠0,ie.,i,α,β∑( ξi/ vβ)^2≠0. Furthermore, i,a,B i,a,~ the authors investigate some structures associated with the Olver water wave (AOWW) equations including Lie algebra and Darboux transformation. The results are also extended to AOWW equations such as Lax, Sawada-Kotera, Kaup-Kupershmidt, It6 and Caudrey-Dodd-Cibbon-Sawada-Kotera equations, et al. Finally, the symmetries are ap- plied to investigate the initial value problems and Darboux transformations. 展开更多
关键词 Generalized symmetries Darboux transformations Analytical solutions
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The Majorana neutrino mass matrix indicated by the current data
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作者 ZHANG XinYi MA BoQiang 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2015年第7期36-48,共13页
The Majorana neutrino mass matrix combines information from the neutrino masses and the leptonic mixing in the flavor basis. Its invariance under some transformation matrices indicates the existence of certain residua... The Majorana neutrino mass matrix combines information from the neutrino masses and the leptonic mixing in the flavor basis. Its invariance under some transformation matrices indicates the existence of certain residual symmetry. We offer an intuitive display of the structure of the Majorana neutrino mass matrix, using the whole set of the oscillation data. The structure is revealed depending on the lightest neutrino mass. We find that there are three regions with distinct characteristics of structure. A group effect and the μ-T exchange symmetry are observed. Six types of texture non-zeros are shown. Implications for flavor models are discussed. 展开更多
关键词 NEUTRINO Majorana mass matrix oscillation data
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Bosonized Supersymmetric Sawada–Kotera Equations: Symmetries and Exact Solutions
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作者 刘萍 曾葆青 刘黎明 《Communications in Theoretical Physics》 SCIE CAS CSCD 2015年第4期413-422,共10页
The Bosonized Supersymmetric Sawada–Kotera(BSSK) system is constructed by applying bosonization method to a Supersymmetric Sawada–Kotera system in this paper. The symmetries on the BSSK equations are researched and ... The Bosonized Supersymmetric Sawada–Kotera(BSSK) system is constructed by applying bosonization method to a Supersymmetric Sawada–Kotera system in this paper. The symmetries on the BSSK equations are researched and the calculation shows that the BSSK equations are invariant under the scaling transformations, the space-time translations and Galilean boosts. The one-parameter invariant subgroups and the corresponding invariant solutions are researched for the BSSK equations. Four types of reduction equations and similarity solutions are proposed. Period Cnoidal wave solutions, dark solitary wave solutions and bright solitary wave solutions of the BSSK equations are demonstrated and some evolution curves of the exact solutions are figured out. 展开更多
关键词 bosonized supersymmetric Sawada–Kotera equations SYMMETRIES exact solution Sawada–Kotera equation bosonization method
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On Hidden Symmetries of d > 4 NHEK-N-Ad S Geometry
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作者 徐杰 岳瑞宏 《Communications in Theoretical Physics》 SCIE CAS CSCD 2015年第1期31-35,共5页
As well known, all higher dimensional Kerr-NUT-Ads metrics with arbitrary rotation and NUT parameters in an asymptotically Ad S spacetime have a new hidden symmetry. In this paper, we show that in the near horizon,the... As well known, all higher dimensional Kerr-NUT-Ads metrics with arbitrary rotation and NUT parameters in an asymptotically Ad S spacetime have a new hidden symmetry. In this paper, we show that in the near horizon,the isometry group is enhanced to include the dilatation and special conformal transformation, and find the conformal transformation contains the cosmological constant. It is demonstrated that for near horizon extremal Kerr-NUT-Ads(NHEK-N-Ad S) only one rank-2 Killing tensor decomposes into a quadratic combination of the Killing vectors in terms of conformal group, while the others are functionally independent. 展开更多
关键词 near horizon black holes Killing tensors hidden symmetries uniform reduced form
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