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Dynamic background modeling using tensor representation and ant colony optimization

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Science China Mathematics 2017年第11期60卷 2287-2302页

作者： PENG Lizhong ZHANG Fan ZHOU BingYin School of Mathematical Sciences Peking University College of Mathematics and Information Sciences Hebei Normal University

Background modeling and subtraction is a fundamental problem in video analysis. Many algorithms have been developed to date, but there are still some challenges in complex environments, especially dynamic scenes in which backgrounds are themselves moving, such as rippling water and swaying trees. In this paper, a novel background modeling method is proposed for dynamic scenes by combining both tensor representation and swarm intelligence. We maintain several video patches, which are naturally represented as higher order tensors,to represent the patterns of background, and utilize tensor low-rank approximation to capture the dynamic nature. Furthermore, we introduce an ant colony algorithm to improve the performance. Experimental results show that the proposed method is robust and adaptive in dynamic environments, and moving objects can be perfectly separated from the complex dynamic background.

关键词：建模方法动态背景蚁群优化量表视频分析复杂环境动态场景蚁群算法

Superomniphobic surfaces for easy-removals of environmentalrelated liquids after icing and melting

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Nano Research 2023年第2期16卷 3267-3277页

作者： lizhong Wang Ze Tian Xiao Luo Changhao Chen Guochen Jiang Xinyu Hu Rui peng Hongjun Zhang Minlin Zhong Laser Materials Processing Research Center Key Laboratory for Advanced Materials Processing Technology(Ministry of Education)Joint Research Center for Advanced Materials&Anti-icing of Tsinghua University(SMSE)-AVIC ARISchool of Materials Science and EngineeringTsinghua UniversityBeijing 100084China

Superhydrophobic surfaces often lose the easy-removal ability of liquids during icing&melting cycles due to the impalement phenomena of air pockets.Especially for the most common mixed liquids in normal life,their difficult-removals after icing and melting have brought colossal troubles in the fields of aviation,energy,biomedicine,etc.Here we adopt the ultrafast laser to fabricate the optimal micro-nanostructured surfaces,realizing excellent superomniphobicity for seven environmental-related liquids.It is demonstrated that different droplets on the surfaces recover well to the original Cassie-Baxter state after melting,and can be removed easily at low tilted angles.The ice adhesion strengths of the seven liquids as low as 5 kPa and the micro-nanostructure durability ensure the long-term easy-removal after icing.Compared with the ice adhesion strength of untreated surfaces(264.4±17.6 kPa),those of our designed surfaces have decreased by over 50 times.Icing and melting processes are investigated to reveal the easy-removal mechanisms that specifically distributed solutes and bubbles after icing impact downwards significantly to accelerate the recovery of the Cassie–Baxter state during melting.A series of environmental-related durability experiments including continuous icing&melting cycles,long-term salt spray,and high-pressure water jet impact further demonstrate the surfaces promising for real applications.

关键词： superomniphobic surfaces easy-removal environmental-related liquids icing melting

Design of smooth orthogonal wavelets with beautiful structure from 2-band to 4-band

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Science in China(Series F) 2006年第1期49卷 128-136页

作者： PENG Lizhong CHU Xiaoyong LMAM School of Mathematical Sciences Peking University Beijing 100871 China

A complete algorithm to design 4-band orthogonal wavelets with beautiful structure from 2-band orthogonal wavelets is presented. For more smoothness, the conception of transfer vanishing moment is introduced by transplanting the requirements of vanishing moment from the 4-band wavelets to the 2-band ones. Consequently, the design of 4-band orthogonal wavelets with P vanishing moments and beautiful structure from 2-band ones with P transfer vanishing moments is completed.

关键词： transfer vanishing moment 4-band wavelet system beautiful structure.

Lifting scheme of symmetric tight wavelets frames

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Science in China(Series F) 2008年第8期51卷 1117-1124页

作者： ZHUANG BoJin YUAN WeiTao PENG Lizhong Laboratory of Mathematics and Applied Mathematics School of Mathematical Sciences Peking UniversityBeijing 100871 China

This paper proposes a method to realize the lifting scheme of tight frame wavelet filters. As for 4-channel tight frame wavelet filter, the tight frame transforms＇ matrix is 2×4, but the lifting scheme transforms＇ matrix must be 4×4. And in the case of 3-channel tight frame wavelet filter, the transforms＇ matrix is 2×3, but the lifting scheme transforms＇ matrix must be 3×3. In order to solve this problem, we introduce two concepts： transferred polyphase matrix for 4-channel filters and transferred unitary matrix for 3-channel filters. The transferred polyphase matrix is symmetric/antisymmetric. Thus, we use this advantage to realize the lifting scheme.

关键词： lifting scheme tight frame wavelet transform

The Paley-Wiener theorem in the non-commutative and non-associative octonions

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Science China Mathematics 2009年第1期52卷 129-141页

作者： LI XingMin PENG Lizhong QIAN Tao School of Computer South China Normal UniversityGuangzhou 510631China LMAM School of ComputerPeking UniversityBeijing 100871China Faculty of Science and Technology the University of Macao3001Macao

The Paley-Wiener theorem in the non-commutative and non-associative octonion analytic function space is proved.

关键词： octonionic exponential function octonionic Taylor expansion Fourier transform Paley-Weiner theorem

IN MEMORIAM PROFESSOR DONGGAO DENG

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Analysis in Theory and Applications 2009年第1期25卷 1-3页

作者： lizhong peng Lixin Yan School of Mathematical Sciences Peking University Beijing 100871 P. R. China School of Mathematics and Computational Science Sun Yat-sen University Guangzhou 510275 P. R. China

Donggao Deng, professor of mathematics, the associate Editor of ATA,was born in June 8, 1935 in Rongqi Town, Shunde City, GuangdongProvince, China. He passed away by illness in Guangzhou on October21, 2007.

关键词： IN MEMORIAM PROFESSOR DONGGAO DENG

Genome-wide association study revealed genetic variations of ABA sensitivity controlled by multiple stress-related genes in rice

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Stress Biology 2021年第1期1卷 120-131页

作者： Lei peng Tingting Xie Zilong Guo Xiaokai Li Yu Chang Haifu Tu Shengchang Wang Nai Wu Yilong Yao lizhong Xiong National Key Laboratory of Crop Genetic Improvement Hubei Hongshan LaboratoryHuazhong Agricultural UniversityWuhan 430070China

Abscisic acid(ABA)is a critical phytohormone that regulates multiple physiological processes including plant growth and stress tolerance.The core ABA signaling pathway has been well established,but genetic variations mediating ABA responses remain largely unknown.In this study,we performed genome-wide association study(GWAS)to identify loci and genes associated with ABA sensitivity(reflected by seed germination inhibition by ABA)in a panel of 425 rice accessions.The seed germination assay revealed that Aus and indica rice had stronger ABA sensitivity than japonica rice.A total of 48 non-redundant association loci were detected in the indica subpopulation and whole population,and 386 genes in these loci were responsive to ABA or abiotic stresses.Eight association loci were overlapped with previously reported loci for yield under drought stress or for droughtindicative image traits.Haplotype analyses of important candidate genes such as OsSAPK6,a key component in the ABA signaling core,were performed to identify key SNPs/InDels that may affect gene functions through promoter activity regulation,amino acid variation,or gene splicing.These results provide insights into the genetic basis of ABA sensitivity related to stress responses.

关键词： ABA sensitivity Seed germination Stress response Rice

HARDY SPACE AND BERGMAN SPACE ON THE OCTONIONS

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Analysis in Theory and Applications 2000年第3期16卷 72-84页

作者： PENG Lizhong Zhao Jiman Department of Mathematics Peking UniversityBeijing 100871PRC

In this paper, square-integrable Octonion-valued function spaces on R3 and R7 are decomposed into the direct sum of Octonion Hardy and conjugate Hardy spaces, and square-integrable Octonion function spaces on the upper half spaces R + 4 and R + 8 are decomposed into infinity direct sum of subspaces in which the first components are just the Octonion Bergman spaces. The Octonion Hardy Spaces on R3 and R7 are characterized.

关键词： function spaces Hardy spaces Bergman spaces

ON STEIN-WEISS CONJUGATE HARMONIC FUNCTION AND OCTONION ANALYTIC FUNCTION

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Analysis in Theory and Applications 2000年第2期16卷 28-36页

作者： Li Xingmin PENG Lizhong Department of Mathematics Guangzhou Normal University510405GuangzhouP.R.China Department of Mathematics Peking University100871BeijingP.R.China

It is shown that the Stein-Weiss conjugate harmonic function is the Quarternion and the Octonion analytic function. We find a counter example to show the converse is not ture in the Octonion case, by which we have ans... 详细信息

关键词： oscillatory integral operator multiplier singularity