作者机构：
[Zhu, Kaixuan] Hunan Univ Arts & Sci, Coll Math & Phys Sci, Hunan Prov Cooperat Innovat Ctr Construct & Dev D, Changde 415000, Peoples R China.;[Xie, Yongqin] Changsha Univ Sci & Technol, Sch Math & Stat, Changsha 410114, Peoples R China.;[Zhou, Feng] China Univ Petr East China, Coll Sci, Qingdao 266580, Peoples R China.;[Li, Xin] Yanshan Univ, Sch Sci, Qinhuangdao 066004, Hebei, Peoples R China.
通讯机构：
[Kaixuan Zhu *] H;[Yongqin Xie; Xin Li] S;[Feng Zhou] C;School of Mathematics and Statistics, Changsha University of Science and Technology, Changsha, 410114, P.R. China. E-mail: [email protected]<&wdkj&>[email protected]<&wdkj&>Hunan Province Cooperative Innovation Center for the Construction and Development of Dongting Lake Ecological Economic Zone, College of Mathematics and Physics Science, Hunan University of Arts and Science, Changde, 415000, P.R. China. E-mail: [email protected]<&wdkj&>[email protected]<&wdkj&>College of Science, China University of Petroleum (East China), Qingdao, 266580, P.R. China. E-mail: [email protected]<&wdkj&>[email protected]<&wdkj&>School of Science, Yanshan University, Qinhuangdao, 066004, P.R. China. E-mail: [email protected]<&wdkj&>[email protected]
期刊：
Journal of Mathematical Physics,2019年60(3):032702 ISSN：0022-2488
通讯作者：
Zhu, Kaixuan
作者机构：
[Zhu, Kaixuan] Hunan Univ Arts & Sci, Coll Math & Phys Sci, Hunan Prov Cooperat Innovat Ctr Construct & Dev D, Changde 415000, Peoples R China.;[Xie, Yongqin] Changsha Univ Sci & Technol, Sch Math & Stat, Changsha 410114, Hunan, Peoples R China.;[Zhou, Feng] China Univ Petr East China, Coll Sci, Qingdao 266580, Shandong, Peoples R China.;[Li, Xin] Yanshan Univ, Sch Sci, Qinhuangdao 066004, Hebei, Peoples R China.
通讯机构：
[Zhu, Kaixuan] H;Hunan Univ Arts & Sci, Coll Math & Phys Sci, Hunan Prov Cooperat Innovat Ctr Construct & Dev D, Changde 415000, Peoples R China.
关键词：
integral equations;reaction-diffusion systems
摘要：
In this paper, we prove the existence of the pullback attractors in L-2 (R-N), L-p (R-N), and H-1 (R-N) for a nonlinear reaction-diffusion equation in unbounded domains, in which the nonlinearity f satisfies the polynomial growth of arbitrary order p - 1(p > 2) and the external forcing g is an element of L-loc(2) (R; L-2 (R-N)) only subjects to the weaker integrability condition integral(t)(-infinity) e(alpha s)parallel to g(s)parallel to(2)(2)ds. Published under license by AIP Publishing.
通讯机构：
[Xiang, Lingyun] C;Changsha Univ Sci & Technol, Hunan Prov Key Lab Intelligent Proc Big Data Tran, Changsha 410114, Hunan, Peoples R China.;Changsha Univ Sci & Technol, Sch Comp & Commun Engn, Changsha 410114, Hunan, Peoples R China.
关键词：
Linguistic steganography;Steganalysis;Compression;Selection;Synonym substitution;Word indexing
摘要：
In this paper, a novel linguistic steganography with high imperceptibility and undetectability is proposed via secret message compression and candidate text selection. The length of the practical embedded payload can be reduced by the proposed word indexing compression algorithm(WIC), while a best stego text with high undetectability can be selected from candidates by the stego text selection strategy. WIC algorithm losslessly compresses the secret message by combining a minimum maximum weight algorithm with Huffman coding under the help of the candidate cover text. To improve the anti-steganalysis capability, ten cover texts with small compression ratios are selected from a huge cover text set, and are embedded the corresponding compressed secret message by using synonym substitutions. Only one stego text is selected by a given rule derived from the distance between a cover text and its stego text. Experimental results show that the proposed compression algorithm achieves better compression ratios than Huffman and LZW coding algorithms leading to higher embedding efficiency, and our steganography performs well in anti-steganalysis capability with compression and the stego text selection rule.
关键词：
Integrity authentication;fixed point image;Gaussian convolution and deconvolution (GCD)
摘要：
Based on the fixed point theory, this paper proposes a new scheme for image integrity authentication, which is very different from digital signature and fragile watermarking. By the new scheme, the sender transforms an original image into a fixed point image (very close to the original one) of a well-chosen transform and sends the fixed point image (instead of the original one) to the receiver; using the same transform, the receiver checks the integrity of the received image by testing whether it is a fixed point image and locates the tampered areas if the image has been modified during the transmission. A realization of the new scheme is based on Gaussian convolution and deconvolution (GCD) transform, for which an existence theorem of fixed points is proved. The semifragility is analyzed via commutativity of transforms, and three commutativity theorems are found for the GCD transform. Three iterative algorithms are presented for finding a fixed point image with a few numbers of iterations, and for the whole procedure of image integrity authentication; a fragile authentication system and a semifragile one are separately built. Experiments show that both the systems have good performance in transparence, fragility, security, and tampering localization. In particular, the semifragile system can perfectly resist the rotation by a multiple of 90 degrees flipping and brightness attacks.
摘要：
In this study, a new quaternion filter for removal of Gaussian noise in colour images is presented. It is based on the quaternion representation of colour images and the optimisation of a tight bound of the quaternion mean-square error between the restored colour image and the original one, together with the essential idea of the non-local means filter. The optimal weights are obtained by using the method of Lagrange multipliers. The authors' quaternion optimal weights non-local means filter is given by the weighted means of the observed quaternion representation using the optimal weights. Experiments on commonly used images are provided to illustrate the efficiency of the proposed filter.
期刊：
Acta Mathematica Academiae Paedagogicae Nyiregyhaziensis,2014年30(1):125-131 ISSN：0866-0182
作者机构：
[Li X.; Yong W.] Department of Mathematics and Computing Science, Changsha University of Science and Technology, Changsha, Hunan, China
关键词：
Almost Hermitian manifold;Con-nection;CR-submanifold;Distribution;Integrability
摘要：
In this paper, we give some suffcient and necessary conditions for integrability of distributions on an almost Hermitian manifold and a quasi Kaehlerian manifold, and generalize Bejancu's and WanYong's re-search work.
期刊：
Advances in Difference Equations,2013年2013(1):1-11 ISSN：1687-1839
通讯作者：
Li, Xiaoai
作者机构：
[Li, Xiaoai; Zou, Jiezhong] Cent S Univ, Sch Math & Stat, Changsha 410083, Hunan, Peoples R China.;[Zhu, Enwen] Changsha Univ Sci & Technol, Sch Math & Computat Sci, Changsha 410004, Hunan, Peoples R China.
通讯机构：
[Li, Xiaoai] C;Cent S Univ, Sch Math & Stat, Changsha 410083, Hunan, Peoples R China.
关键词：
impulses;pth moment exponentially stable;Razumikhin theory;stochastic cellular neural network
摘要：
This paper studies the p th moment exponential stability of stochastic cellular neural networks with time-varying delays under impulsive perturbations. Based on the Lyapunov function, Razumikhin theory, stochastic analysis and differential inequality technique, criteria on the p th moment exponential stability of this model are derived. These results generalize and improve some of the existing ones. A numerical example illustrates the effectiveness and improvements of our results.
期刊：
SCIENCE IN CHINA SERIES A-MATHEMATICS,2007年50(5):698-704 ISSN：1006-9283
通讯作者：
Li, Ying-qiu
作者机构：
[Li, Ying-qiu] Changsha Univ Sci & Technol, Sch Math & Comp Sci, Changsha 410076, Peoples R China.;Univ Bretgne Sud, LMAM, F-56017 Vannes, France.
通讯机构：
[Li, Ying-qiu] C;Changsha Univ Sci & Technol, Sch Math & Comp Sci, Changsha 410076, Peoples R China.
关键词：
random walks in random environments;branching processes in random environments;rightmost particles;phase transition;large deviation
摘要：
We consider a branching random walk in random environments, where the particles are reproduced as a branching process with a random environment (in time), and move independently as a random walk on Z with a random environment (in locations). We obtain the asymptotic properties on the position of the rightmost particle at time n, revealing a phase transition phenomenon of the system.
