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Asymptotic Behavior of Gibbs Functions for M-Band Wavelet Expansions

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Acta Mathematica Sinica,English Series 1999年第2期15卷 165-172页

作者： Daren Huang zeyin zhang, Center for Mathematical Sciences, Zhejiang University, Hangzhou 310027, P. R. China Center for Mathematical Sciences Zhejiang University Hangzhou P. R. China

In this paper the asymptotic behavior of Gibbs function for a class of M-band wavelet expansions is given. In particular, the Daubechies’ wavelets are included in this class.

关键词： Gibbs phenomenon Wavelet expansion Filter Scaling function Vanishing moment

PARAMETERIZATION OF SYMMETRIC SCALING FUNCTIONS

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Applied Mathematics(A Journal of Chinese Universities) 2004年第1期19卷 77-80页

作者： zhangzeyin ZhejiangUniv. Hangzhou310027Chinazeyinz@***

In this paper,the factorization for filters with length Km of scaling functions into simple blocks is considered.

关键词： scaling function filter bank wavelet,polyphase representation.

ON PARAMETRIC FACTORIZATION OF BI-ORTHOGONAL LAURENT POLYNOMIAL WAVELET FILTERS

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Approximation Theory and Its Applications 2002年第2期18卷 31-37页

作者： Hu Junquan Huang Daren zhang zeyin (Zhejiang University, China) Department of mathematics Zhejiang University Hangzhou Zhejiang PRC

In this paper, we study the factorization of bi-orthogonal Laurent polynomial wavelet matrices with degree one into simple blocks. A conjecture about advanced factorization is given.

关键词： Haar BI POLYNOMIAL WAVELET FILTERS ON PARAMETRIC FACTORIZATION OF BI-ORTHOGONAL LAURENT

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WAVELET TECHNIQUE RECOVERING IMAGE BLURRED BY MIXED GAUSSIAN AND SALT-PEPPER NOISE

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Analysis in Theory and Applications 2003年第2期19卷 185-192页

作者： Hu Junquan, Huang Daren, Wang Zhenwu and zhang zeyin (Zhejiang University,China) Department of Mathematics Zhejiang University Hangzhou 310027 P.R.China Department of Mathematics Zhejiang University Hangzhou P. R. China

In this paper, we propose a new method to removing the mixed Gaussian and salt-pepper noise based on wavelet. To estimate outlier, A scheme called max-min method is adopted after DWT. Experimental results show that this method is more effective than common image restoration methods, such as Median filter, center weighted median filter.

关键词： wavelet max-min method

CONSTRUCTION OF COMPACTLY SUPPORTED SEMI-ORTHOGONAL WAVELETS

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Applied Mathematics(A Journal of Chinese Universities) 2003年第4期18卷 453-460页

作者： BiNing HuangDaren zhangzeyin Dept.ofScientificComputingandComputerApplication SunYat-senUniv.Guangzhou510275China Dept.ofScientificComputingandComputerApplication SunYat-senUniv.Guangzhou510275China CenterforMathematicalSciences ZhejiangUniv.Hanghou310027China

In this paper,the construction of M-band semi-orthogonal wavelets and some examples of B-spline wavelets are given.

关键词： semi-orthogonal filter length of the Laurent polynomial B-spline

A novel radar operating mode identification approach based on variational relevance vector machine with chaotic gravitational search optimization

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A novel radar operating mode identification approach based o...

A non-uniform Gauss pseudospectral method based on curvature information for dynamic optimization problem

第32届中国过程控制会议(CPCC2021)

作者： Ruping Zou Xinjie Chen Shichao Chen Wenhai Wang Jun Wang zeyin zhang Xinggao Liu Xi'an modern Control Technology Research Institute Zhejiang University NGICS Platform State Key Laboratory of Industrial Control TechnologyControl DepartmentZhejiang University Mathematics Department Zhejiang University

Radar operating mode identification is one of the top priorities in the electronic countermeasure field for evaluating threat and behavior ***,most of the existing identification methods usually extract features based on prior knowledge manually,which have the drawbacks of lagging inference time and unsatisfactory identification *** efficient identification approach for radar operating mode is therefore proposed without prior knowledge,where the variational relevance vector machine(VRVM) model of operating modes identification is therefore first presented based on the Bayesian probability *** an improved chaotic gravity search algorithm(CGSA) is developed to increase the search breadth and effectively optimize the hyperparameters of ***,a novel filter method named Threshold-One-Versus-One(TOVO) is further proposed to screen the identification results to form the final radar operating mode identification *** experimental results demonstrate that the proposed approach can accurately distinguish operating mode in real-time without any prior knowledge.

关键词： Radar operating mode identification Real-time identification without prior knowledge Variational relevance vector machine Machine learning Chaotic gravitational search optimization

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A non-uniform Gauss pseudospectral method based on curvature...

立式铣削刀轨重叠率对316L不锈钢工件表面完整性的影响

第32届中国过程控制会议(CPCC2021)

作者： Lu Lv Qian zhang Jianzhong Su Wenhai Wang Jianquan Yuan Zijian Tian Zhenghui zhang Long Xiao zeyin zhang Xinggao Liu Zhejiang University NGICS Platform State Key Laboratory of Industrial Control TechnologyControl DepartmentZhejiang University Tianjin Jinhang Institute of Technical Physics Science and Technology on Complex System Control and Intelligent Agent Cooperative Laboratory Mathematics Department Zhejiang University

Dynamic optimization for hypersonic reentry vehicle(HRV) is a challenge for complex nonlinear constraints during a global strike *** to the strong nonlinearity of HRV,it is difficult to guarantee the precision of complex constraints on non-collocation points with traditional Gauss pseudospectral method(GPM).A novel approach which provides an optimal control strategy considering the above challenges is then ***,an adaptive mesh refinement strategy based on curvature information is presented to improve the accuracy of GPM.A collocation point redistribution method based on error analysis is then proposed to further improve the accuracy of the ***,a detection mechanism is proposed to correct the results on-line when the path constraint is not *** proposed approaches are finally applied to a classic HRV problem and compared with other literature work in *** research results validate the effectiveness of the proposed methods.

关键词： nonlinear optimal control Gauss pseudospectral method adaptive mesh refinement hypersonic reentry vehicle

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机械设计与研究 2016年第5期32卷 115-118页

作者：张泽胤罗磊张德清上海交通大学机械与动力工程学院上海200030

平底铣刀立式铣削加工过程中,当行间距小于刀具直径时,将会在相邻刀具路径之间形成重叠区域。重叠区域的大小不但会影响铣削加工效率,同时也会影响工件加工表面完整性。以316L不锈钢材料作为研究对象,采用重叠率来表示重叠区域大小与刀... 详细信息

平底铣刀立式铣削加工过程中,当行间距小于刀具直径时,将会在相邻刀具路径之间形成重叠区域。重叠区域的大小不但会影响铣削加工效率,同时也会影响工件加工表面完整性。以316L不锈钢材料作为研究对象,采用重叠率来表示重叠区域大小与刀具直径大小的比值,通过有限元仿真与试验分析相结合的方式,研究重叠率对铣削加工表面完整性的影响,包括表面残余应力、表面粗糙度、表面加工硬化等属性,为316L不锈钢材料立式铣削加工过程中行间距的选择提供参考。研究结果表明,表面残余应力与表面加工硬化程度在重叠率小于0.5时,会随着重叠率的增加而增大;而当重叠率大于0.5时,又会随着重叠率的增加而减小。表面粗糙度在重叠率小于0.3时,会随着重叠率的增大而减小;当重叠率在0.3到0.5之间,会随着重叠率的增大而增大;而当重叠率大于0.5时,又会出现下降趋势。

关键词：重叠率行间距表面完整性三维有限元模型立式铣削

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MRI测量中国健康成人脑杏仁核体积

中国医学影像技术 2021年第2期37卷 179-183页

作者：赵莹张静杜佳晨张泽寅梁佩鹏李坤成首都医科大学宣武医院放射与核医学科北京100053 北京市仁和医院放射科北京102600 首都师范大学心理学院北京100048 磁共振成像脑信息学北京市重点实验室北京100053

目的采用MRI测量不同年龄中国健康成人杏仁核体积。方法于中国健康成人MRI脑数据库中选取100名志愿者,按照年龄分为18~30岁、3l~40岁、4l~50岁、5l~60岁和6l~70岁组共5组,每组男、女性各10名。采集头部三维磁化准备双快速采集梯度回波... 详细信息

目的采用MRI测量不同年龄中国健康成人杏仁核体积。方法于中国健康成人MRI脑数据库中选取100名志愿者,按照年龄分为18~30岁、3l~40岁、4l~50岁、5l~60岁和6l~70岁组共5组,每组男、女性各10名。采集头部三维磁化准备双快速采集梯度回波序列图像,获得双侧杏仁核体积及大脑容积,再以颅腔容积进行校正;比较不同年龄左、右侧及不同年龄男、女性杏仁核体积差异,分析杏仁核体积与年龄的关系。结果校正前、后左侧杏仁核体积[(992.46±132.95)mm^(3)、(993.52±106.41)mm^(3)]均小于右侧[(1062.19±127.43)mm^(3)、(1064.11±102.25)mm^(3);t=-14.25、-13.85,P均<0.01]。校正前后不同年龄组双侧杏仁核体积差异均有统计学意义(P均<0.05)。校正前31~50岁男性左侧杏仁核体积均高于女性(P均<0.01),18~50岁男性右侧杏仁核体积均高于女性(P均<0.05);校正后41~50岁男性左侧杏仁核体积高于女性(P<0.05)。校正前后左、右侧杏仁核体积与年龄均呈负相关(校正前r=-0.37、-0.46,P均<0.01;校正后r=-0.28、-0.34;P均<0.01)。结论中国健康成人杏仁核体积男、女性杏仁核体积基本一致,均随年龄增大而缩小;左侧杏仁核体积小于右侧。

关键词：杏仁核脑磁共振成像体积