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Steganalysis of stochastic modulation steganography

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science in china(Series F) 2006年第3期49卷 273-285页

作者： HE Junhui1,2.& HUANG Jiwu1,2.1. School of information science and Technology, Sun Yat-sen {2., Guangzhou 5102.5, china 2. Guangdong Province Key Laboratory of information Security, Guangzhou 5102.5, china 1. School of information science and Technology Sun Yat-sen University Guangzhou 510275 China 2. Guangdong Province Key Laboratory of information Security Guangzhou 510275 China

Stochastic modulation steganography embeds secret message within the cover image by adding stego-noise with a specific probabilistic distribution. No method is known to be applicable to the estimation of stochastic modulation steganography. By analyzing the distributions of the horizontal pixel difference of images before and after stochastic modulation embedding, we present a new steganalytic approach to accurately estimate the length of secret message in stochastic modulation steganography. The pro- posed method first establishes a model describing the statistical relationship among the differences of the cover image, stego-image and stego-noise. In the case of stegoimage-only steganalysis, rough estimate of the distributional parameters of the cover image＇s pixel difference is obtained with the use of the provided stego-image. And grid search and Chi-square goodness of fit test are exploited to estimate the length of the secret message embedded with stochastic modulation steganography. The experimental results demonstrate that our new approach is effective for steganalyzing stochastic modulation steganography and accurately estimating the length of the secret message.

关键词： information hiding steganography steganalysis stochastic modulation statistical distribution models of difference.

Imaging theory of nonlinear second harmonic and third harmonic generations in confocal microscopy

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science china(Physics,Mechanics & Astronomy) 2004年第1期47卷 8-16页

作者： TANG Zhilie1, XING Da2.& LIU Songhao2.1. Department of Physics, South china normal {2., Guangzhou 510631, china 2. School for information and Optoelectronic science and Engineering, South china normal {2., Guangzhou 510631, china Correspondence should be addressed to Tang Zhilie (email: tangzhl@***) Received April 2., 2.03 1. Department of Physics South China Normal University 510631 Guangzhou China 2. School for information and Optoelectronic science and Engineering South China Normal University 510631 Guangzhou China

The imaging theory of nonlinear second harmonic generation (SHG) and third harmonic generation (THG) in confocal microscopy is presented in this paper. The nonlinear effect of SHG and THG on the imaging properties of confocal microscopy has been analyzed in detail by the imaging theory. It is proved that the imaging process of SHG and THG in confocal microscopy, which is different from conventional coherent imaging or incoherent imaging, can be divided into two different processes of coherent imaging. The three-dimensional point spread functions (3D-PSF) of SHG and THG confocal microscopy are derived based on the nonlinear principles of SHG and THG. The imaging properties of SHG and THG confocal microscopy are discussed in detail according to its 3D-PSF. It is shown that the resolution of SHG and THG confocal microscopy is higher than that of single- and two-photon confocal microscopy.

关键词： second harmonic generation, third harmonic generation, confocal microscopy, three-dimensional point spread function.

Adaptive synchronization of neural networks with different attractors

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Progress in Natural science:Materials International 2007年第6期17卷 687-695页

作者： Zhang Huaguang1, Guan Huanxin1 and Wang Zhanshan1,2.1. School of information science and Engineering, Northeastern {2., Shenyang 110004, china 2. School of information science and Engineering, Shenyang Ligong {2., Shenyang 110168, china) [a]School of information science and Engineering Northeastern University Shenyang China [b]School of information science and Engineering Shenyang Ligong University Shenyang China

This paper aims to present an adaptive control scheme for the synchronization of two classes of uncertain neural networks with different attractors. A new sufficient condition for the global synchronization of two kinds of neural networks with different attractors is derived. The proposed control method is efficient and easy to be implemented. Numerical simulation is used to show the effectiveness of the obtained result.

关键词： neural networks attractor adaptive synchronization linear matrix inequality.

Weighted estimates for the multilinear singular integral operators with non-smooth kernels

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science china {2. 2011年第3期54卷 587-602页

作者： HU GuoEn1 & LU ShanZhen2.1Department of Applied mathematics, Zhengzhou information {2. and Technology Institute, Zhengzhou 450002. china 2.epartment of mathematics, Beijing normal university, Beijing 100875, china 1. Department of Applied mathematics Zhengzhou Information Science and Technology Institute Zhengzhou 450002 China2. Department of Mathematics Beijing Normal University Beijing 100875 China

In this paper, by sharp function estimates and certain weak type endpoint estimates, the authors establish some weighted norm inequalities with Ap weights for the multilinear singular integral operators with non-smoot... 详细信息

关键词： approximation to the identity weighted norm inequality singular integral operator non-smooth kernel Calderón-Zygmund decomposition

Denitrification in Chongming east tidal flat sediment, Yangtze estuary, china

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science china Earth sciences 2006年第10期49卷 1090-1097页

作者： WANG Dongqi1,2. CHEN Zhenlou1,3, XU Shiyuan1,2. HU Lingzhen1 & WANG Jun1,2.1. College of Resources & Environment, East china normal {2., Shanghai 2.0062. china 2. State Key Laboratory of Estuarine and Coastal Sediment Dynamics and Morphodynamics, East china normal {2., Shanghai 2.0062. china 3. Key Laboratory of Geographical information science of Ministry of Education,East china normal {2.,Shanghai 2.0062. china 1. College of Resources & Environment East China Normal University Shanghai 200062 China 2. State Key Laboratory of Estuarine and Coastal Sediment Dynamics and Morphodynamics East China Normal University Shanghai 200062 China 3. Key Laboratory of Geographical information science of Ministry of Education East China Normal University Shanghai 200062 China

From July 2.03 to July 2.04, samples were collected on Chongming Island east tidal flat every two months. The research showed that the nitrous oxide (N2.) production rate was very low in the water, Chongming east tidal flat (CM) sediment was the N2. source of the water. Sediment N2. natural production rate was between -0.08 and 1.74 μmolN·m-2.h-1. N2. natural production rate was higher in the summer. The difference of the N2. natural production rate in the different tidal flats, the correlation between the N2. natural production rate and the denitrification rate, and those with the temperature and DO indicate that middle tidal flat sediment denitrification was the main process of the N2. production, while in the low tidal flat sediment, the production of the N2. came from several processes of the nitrogen cycling. Tidal flat sediment denitrification reaction was stronger in summer and winter but relatively lower in the late autumn and early spring. Seasonal change of the sediment denitrification rate was wide, from 1.12.to 33.34 μmolN·m-2.h-1. Temperature, DO and the coactions of them had the prominent effect on the tidal flat sediment denitrification.

关键词： Yangtze estuary, tidal flat sediment, denitrification, nitrous oxide, effect factor.

Dark energy from logarithmically modified gravity and deformed Coleman-Weinberg potential

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Research in Astronomy and Astrophysics 2011年第7期11卷 759-766页

作者： Ahmad Rami El-Nabulsi Department of Nuclear and Energy Engineering Cheju National University College of mathematics and information {2.s Neijiang Normal University

Recent astrophysical measurements strongly suggest the existence of a missing energy component dubbed dark energy that is responsible for the current accelerated expansion of the universe.A new class of modified gravity theory is introduced which yields a universe accelerating in time and dominated by dark *** new modified gravity model constructed here concurrently includes a Gauss-Bonnet invariant term,barotropic fluid with a time-dependent equation of state parameter,a Coleman-Weinberg（CW） potential-like expression V（φ） =ξφm lnφn and a new Einstein-Hilbert term f（R,φ） =E（φ） R which depends on both the scalar curvature and the scalar fieldφthrough a generic logarithmic function E（φ） =lnφ.Here m and n take different values from the standard CW potential andξis a real parameter. It was shown that the presence of these terms provides many useful features which are discussed in some detail.

关键词： dark energy—gravitation—equation of state

On the diophantine equation X^2.(1+a^2.Y^4 =-2.

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science china {2. 2010年第8期53卷 2143-2158页

作者： YUAN PingZhi 1 & ZHANG ZhongFeng 2.1 School of mathematics,South china {2. university,Guangzhou 510631,china 2.School of mathematics & Computational science,Sun Yat-Sen university,Guangzhou 5102.5,china 1. School of mathematics South China Normal University Guangzhou 510631 China2. School of Mathematics & Computational Science Sun Yat-Sen University Guangzhou 510275 China

Let a≥1 be an *** this paper,we will prove the equation in the title has at most three positive integer solutions.

关键词： algebraic approximations continued fractions elliptic curves quartic equations

Ecological Footprint and Ecological Security Evaluation in the Upper Min River Basin

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Wuhan university Journal of Natural sciences 2005年第4期10卷 641-646页

作者： TU Jian-jun 1, 2.1. School of Resources and Environment science, Southwest china {2. university, Chongqing 400715, china 2. Institute of Mountain Hazards and Environment, Chinese Academy of sciences, Chengdu 610041, Sichuan, china Southwest china normal {2. School of Resources and Environment Science Chongqing China (GRID:grid.263906.8) Chinese Academy of sciences Institute of Mountain Hazards and Environment Chengdu Sichuan China (GRID:grid.9227.e) (ISNI:***)

On the basis of the ecological footprint (EF) model, this paper studied theecological security in the Upper Min River Basin ecosystem. The result shows that with 2. 038 2.hm^2.er capita ecological capacity (0. 42. 2.hm^2.higher than per capita EF) ,and 165 82. hm^2.ecologysurplus , the ecosystem in Upper Min River is generally secure at present. But the arable land isoverweighed and omens an eco-security crisis. Meanwhile, problems such as low forest coverage rate,severe loss of water and soil,enlargement of arid-valley area, frequent occurrence of mountainhazards and degradation of pastures have been major threats to the eco-security of this region. Thecalculation result of ten-thousand-yuan ( RMB) GDP shows that the use of natural resources isextensive, and there will be a rapid increase tendency of EF in the future. In order to maintain thepresent eco-security, the ways of use natural resources must be improved in the Upper Min RiverBasin.

关键词： ecological security ecological footprint ecological capacity quantitativeevaluation the Upper Min River Basin

Numerical simulation of Meiyu front and the diagnosis of moist vorticity vector

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Progress in Natural science:Materials International 2007年第11期17卷 1341-1347页

作者： Ping Fan1,2.and Luo Zhexian2.1. Institute of Atmospheric Physics, Chinese Academy of sciences, Beijing 10002., china 2. Nanjing {2. of information sciences & Technology, Nanjing 2.0044, china) Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Nanjing university of information {2.s & Technology Nanjing 210044 China

Moist vorticity vector is introduced to study the development and evolution of mesoscale convective vortex (MCV) in the Meiyu front precipitation with the Advanced Regional Predication System (ARPS). In this study, the heavy rainfall is simulated to investigate the genesis, development and dissipation of middle scale convective vortex, which occurred from 0000 UTC 3 July to 12.0 UTC 5 July over the Jianghuai River valley. Moist vorticity vector (MVV) has zonal, radial and vertical components in its 3D spatial distribution. The simulation shows that the vertical component of moist vorticity vector well demonstrates the spatial distribution characteristics of middle scale convective vortex, especially in the process of Meiyu front precipitation. Diagnosis upon zonal, radial averaged and mass-integrated quantities of MVV shows that its vertical component and the surface precipitating ratio are in phase with a correlation coefficient of 0.68, indicating that the vertical component of MVV is closely associated with the Meiyu front precipitation. In addition, the tendency of the vertical component of MVV is mainly determined by the interaction between the vorticity and the zonal and radial gradient of condensational or depositional heating.

关键词： moist vorticity vector mesoscale convective vortex Meiyu front precipitation