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Perturbations of the radical of nest algebras

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Chinese Science Bulletin 1998年第7期43卷 556-560页

作者： LU Fangyan 1 and LU Shijie 2.1. department of mathematics, Suzhou university, Suzhou 2.5006, China 2. department of mathematics, Zhejiang university, Hangzhou 31002., China department of mathematics Suzhou University Suzhou China department of mathematics Zhejiang University Hangzhou China

Let R N and K-N be the radical ideal and the compact operator ideal of nest algebra T(N) respectively. It is proved thatR-N+K-N=span{T∈T(N)∶TT(N)NCT}=span{T∈T(N): #σ′(ST)≤1, S∈T(N)}.

关键词： nest algebras radical perturbation.

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红外回扫补偿系统图像退化评价方法的研究

激光技术 2024年第1期48卷 121-126页

作者：刘大通刘洋刘力双北京信息科技大学仪器科学与光电工程学院北京100192

为了解决回扫补偿型红外成像系统图像退化程度在线评价问题,采用了基于红外图像梯度相似度的质量评价方法。在结构相似度算法思想的基础上,针对回扫补偿型红外成像系统的特点,提取出能有效度量图像失真变化程度的梯度特征,计算出各子图... 详细信息

为了解决回扫补偿型红外成像系统图像退化程度在线评价问题,采用了基于红外图像梯度相似度的质量评价方法。在结构相似度算法思想的基础上,针对回扫补偿型红外成像系统的特点,提取出能有效度量图像失真变化程度的梯度特征,计算出各子图像块的梯度相似度均值,由此获得整幅图像的梯度相似度。结果表明,对于退化程度相同的图像,测得结构相似度算法的评价数值从0.772.降到0.705,梯度相似度算法的评价数值由0.700下降到0.543。梯度相似度算法对不同退化程度的红外周扫图像的质量变化比常用的结构相似度算法更为灵敏,且不需要平行光管等外部测试设备,这为回扫补偿型红外成像系统在线图像质量评价及优化提供了一种新的方法。

关键词：成像系统图像质量评价结构相似度梯度相似度

Automorphisms with order three of affine Lie algebras

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Chinese Science Bulletin 1998年第21期43卷 1793-1798页

作者： JIN Quanqin 1,2.and HOU Zixin 2.1. department of mathematics, Hebei university, Baoding 071002. China 2. department of mathematics, Nankai university, Tianjin 300071, China department of mathematics Hebei University Baoding China department of mathematics Nankai University Tianjin China

Some properties of automorphisms of affine Lie algebras are presented. Automorphisms with order three are classified up to conjugacy, and their fixed point sets are also computed. As a corollary, it is proved that two... 详细信息

关键词： affine Lie algebra automorphism of order three first (second) kind of automorphism.

Congruences on ideal nil-extension of completely regular semigroups

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Chinese Science Bulletin 1998年第5期43卷 379-381页

作者： REN Xueming 1, 2.GUO Yuqi 2.and CEN Jiaping (Shum Kar-ping) 31. department of mathematics, Xi’an university of Architecture & Technology, Xi’an 710055, China 2. department of mathematics, Yunnan university, Kunming 650091, China 3. department of department of mathematics Xi’an University of Architecture & Technology Xi’an China department of mathematics Yunnan University Kunming China department of mathematics Chinese University of Hong Kong Hong Kong

Let S be an ideal nil-extension of a completely regular semigroup K by a nil semigroup Q with zero. A concept of admissible congruence pairs (δ,ω) of S is introduced, where δ and ω are a congruence on Q and a congruence on K respectively. It is proved that every congruence on S can be uniquely respresented by an admissible congruence pair (δ,ω) of S. Suppose that ρ K denotes the Rees congruence induced by the ideal K of S. Then it is shown that for any congruence σ on S,a mapping Γ:σ|→(σ Q,σ K) is an order-preserving bijection from the set of all congruences on S onto the set of all admissible congruence pairs of S,where σ K is the restriction of σ to K and σ Q=(σ∨ρ K)/ρ K. Moreover,the lattice of congruences of S is also discussed. As a special case,every congruence on completely Archimedean semigroups S is described by an admissible quarterple of S. The following question is asked: Is the lattice of congruences of the completely Archimedean semigroup a semimodular lattice?

关键词： completely regular semigroups ideal nil-extension congruences.

Shape blending of artistic brushstroke represented by disk B-spline curves

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Progress in Natural Science:Materials International 2007年第12期17卷 1501-1507页

作者： Cheng Min1,2.and Wang Guojin1(1. department of mathematics, Zhejiang university, Hangzhou 31002., China 2. department of mathematics, Zhejiang university of Technology, Hangzhou 310032. China) department of mathematics Zhejiang University Hangzhou 310027 China 2. department of mathematics Zhejiang University of Technology Hangzhou 310032 China

This paper presents an algorithm for automatically generating in-between frames of two artistic brushstrokes. The basic idea of the algorithm is to represent the two key frames of artistic brushstrokes in disk B-spline curves, and then make blending of their geometric intrinsic variables. Given two key frames of artistic brushstrokes, the skeleton curves can be obtained by certain skeleton-based techniques. After disk B-spline representation of the key frames is generated, interpolation of the intrinsic variables of the initial and the target disk B-spline curves is carried out. Examples show that this method can efficiently create in-between frames of artistic brushstrokes.

关键词： computer aided calligraphy shape blending brushstroke disk B-spline curve skeleton.

PERMANENCE OF A DISCRETE SINGLE SPECIES SYSTEM WITH DELAYS AND FEEDBACK CONTROL

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Annals of Differential Equations 2011年第4期27卷 463-471页

作者： Xiaojian Ma (School of Math.and Computer Science,datong university,datong 037009,shanxi)

In this paper,a discrete single species system with time delays and feedback control is *** conditions which guarantee the permanence of all positive solutions to this discrete system are *** results show that the fee... 详细信息

关键词： permanence single species discrete delay feedback control

SPECTRUM-PRESERVING ELEMENTARY OPERATORS ON B(X)

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Chinese Annals of mathematics,Series B 1998年第4期19卷 511-516页

作者： HOU JINCHUAN (department of mathematics, shanxi Teachers {2., Linfen 041004, China.) shanxi Teachers Univ Dept Math Linfen 041004 Peoples R China

Characterizations for elementary operators of length 2.to be invertibility-preserving,spectrum-preserving or spectrum-compressing are obtained.

关键词： Elementary operators Spectrum-preserving linear maps Positive maps

Characteristic analysis for a polynomial-like iterative equation

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Chinese Science Bulletin 1998年第3期43卷 192-196页

作者： Janusz Matkowski 1 and ZHANG Weinian 2.1. department of mathematics, Technical university, 43_300 Bielsko_Biala, Poland 2. department of mathematics, Sichuan Union university, Chengdu 610064, China department of mathematics Technical University Bielsko-Biala Poland department of mathematics Sichuan Union University Chengdu China

In the light of Euler’s idea for differential equations,a polynomial_like n _order iterative equation is discussed through analyzing its characteristic polynomial. An unproved result is verified rigorously for the fi... 详细信息

关键词： iterative dynamics functional equation characteristic.

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基于驾驶事件的驾驶风格分类与识别方法研究

中国机械工程 2024年第9期35卷 1534-1541页

作者：秦大同陈沫机曹宇航高迪重庆大学机械传动国家重点实验室重庆400044

针对基于数据统计特征的驾驶风格分类识别方法容易忽略驾驶员在驾驶过程中驾驶风格多样性的问题,提出了一种基于驾驶事件、谱聚类与随机森林相结合的驾驶风格分类识别方法。设计试验采集驾驶数据,进行数据预处理,提取转弯事件和制动事件... 详细信息

针对基于数据统计特征的驾驶风格分类识别方法容易忽略驾驶员在驾驶过程中驾驶风格多样性的问题,提出了一种基于驾驶事件、谱聚类与随机森林相结合的驾驶风格分类识别方法。设计试验采集驾驶数据,进行数据预处理,提取转弯事件和制动事件,经标准化和降维处理后,运用谱聚类算法分别对转弯事件和制动事件进行驾驶风格聚类。采用熵权法赋权得到每位驾驶员的驾驶风格权重,对比5种机器学习算法对驾驶风格识别的精确度,结果表明基于随机森林的驾驶风格识别精确度为92.73%,显著提高了驾驶风格识别准确率。

关键词：驾驶风格驾驶事件谱聚类随机森林