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Simulation of the Earth' s gravitational field recovery from GRACE using the energy balance approach

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Progress in Natural science:Materials International 2005年第7期15卷 596-601页

作者： ZHENG Wei, LU Xiaolei, HSU Houtse, SHAO Chenggang, LUO Jun and WANG Nengchao ( department of physics, huazhong university of science and technology, wuhan 430074, china Institute of Geodesy and Geophysics, Chinese Academy of sciences, wuhan 430077, china department of Mathematics, huazhong university of science and technology, wuhan 430074, china) department of physics Huazhong University of Science and Technology Wuhan 430074 China. department of Mathematics Huazhong University of Science and Technology Wuhan 430074 China. Institute of Geodesy and Geophysics Chinese Academy of Sciences Wuhan 430077 China

Based on the measurement principles of GRACE satellites, the observation equations are set up using the energy balance approach. The Earth's gravitational field complete up to degree and order 120 is recovered applying the preconditioning conjugate gradient iterative approach by numerical simulation. Assuming an accuracy of 1 μm/s in range-rate measurements of the K-band microwave ranging system, the matching relationships of accuracies of K-band microwave ranging system, SuperSTAR Accelerometer, position vector and velocity vector measurements are investigated.

关键词： the Earth’s gravitational field GRACE satellites energy balance approach preconditioning conjugate gradient method.

Quantum Theory of Femtosecond Soliton Propagation in Single-Mode Optical Fibers

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Communications in Theoretical physics 2004年第6期41卷 943-948页

作者： CHEN Shi-Hua ZHANG Shao-Wu SHI Du-Fang department of physics,huazhong university of science and technology,wuhan 430074,china department of physics Huazhong University of Science and Technology Wuhan 430074 China

In this paper we have derived the generalized QNLS equation with considering the third-order dispersion andKerr dispersion,which can be applicable to the femtosecond regime and is suitable for discussing the quantum propertiesof femtosecond solitons in single-mode optical fibers,as compared with its classical *** quantum operatorequation can be solved by many methods such as the linearized perturbations and phase-space ***,owingto the fact that this quantum equation is rather similar to its classical counterpart,all these methods can be facilitatedto a great extent by citing correctly the classical results obtained before.

关键词： generalized QNLS equation single-mode-optical fibers third-order dispersion

A New Multisoliton Solution to (2+1)-Dimensional KdV Equation

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Communications in Theoretical physics 2004年第5期41卷 669-670页

作者： PENG Yan-Ze~(1,2) 1 department of Mathematics,huazhong university of science and technology,wuhan 430074,china2.department of Mathematics and physics,Henan university of science and technology,Luoyang 471003,china department of Mathematics and physics Henan University of Science and Technology Luoyang 471003 China

A new multisoliton solution to the(2+1)-dimensional KdV equation is obtained by means of the truncatedPainleve expansion method and a direct ansatz *** new exact solution is periodic in the propagating directionx and exponentially decaying in y and thus it is called periodic solitons.A typical spatial structure of it is illustrated bythe figures.

关键词： (2+1)-dimensional KdV equation periodic solitons truncated Painleve expansion method

NONLINEAR STABILITY OF NATURAL RUNGE-KUTTA METHODS FOR NEUTRAL DELAY DIFFERENTIAL EQUATIONS

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Journal of Computational Mathematics 2002年第6期20卷 583-590页

作者： Cheng-jian Zhang(department of Mathematics, huazhong university of science and technology, wuhan 430074, Hubei, P. R. china) department of Mathematics Huazhong University of Science and Technology Wuhan 430074

Presents the stability analysis of theoretical solutions for a class of nonlinear neutral delay-differential equations (NDDE). Discussion on the numerical analogous results of the natural Runge-Kutta (NRK) methods for the same class of nonlinear NDDE; Review of the related concepts and results on RK methods; Information on the asymptotic stability and global stability of the induced NRK method.

关键词： nonlinear stability neutral delay differential equations natural Runge-Kutta methods

Applications of semigroups of operators to non-elliptic differential operators

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Chinese science Bulletin 2000年第8期45卷 673-682页

作者： ZHENG Quandepartment of Mathematics, huazhong university of science and technology, wuhan 430074, china department of Mathematics Huazhong University of Science and Technology Wuhan China

This paper treats systematically the semigroup method of non-elliptic differential operators, which was developed in the last ten years. In particular, a review of the applications of regularized semigroups to non-elliptic differential operators with constant coefficients or time-dependent coefficients, parabolic systems, correct systems, abstract differential operators and pseudodifferential operators is given here. It is also shown that the regularized semigroup is an appropriate tool for non-elliptic differential operators and is far superior to the integrated semigroup approach.

关键词： differential operator regularized semigroup integrated semigroup initial value problem Fourier multiplier.

Robust H-infinity fuzzy control for uncertain Markovian jump nonlinear singular systems with wiener process

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控制理论与应用（英文版） 2010年第2期8卷 205-210页

作者： Aiqing ZHANG 1 , Huajing FANG 2 (1.College of Mathematics and Computer science, Jianghan university, wuhan Hubei 430056, china 2.department of Control science and Engineering, huazhong university of science and technology, wuhan Hubei 430074, china) College of Mathematics and Computer science Jianghan University Wuhan Hubei China department of Control science and Engineering Huazhong University of Science and Technology Wuhan Hubei China

This paper deals with the problems of robust stochastic stabilization and H-infinity control for Markovian jump nonlinear singular systems with Wiener process via a fuzzy-control approach. The Takagi-Sugeno (T-S) fuzzy model is employed to represent a nonlinear singular system. The purpose of the robust stochastic stabilization problem is to design a state feedback fuzzy controller such that the closed-loop fuzzy system is robustly stochastically stable for all admissible uncertainties. In the robust H-infinity control problem, in addition to the stochastic stability requirement, a prescribed performance is required to be achieved. Linear matrix inequality (LMI) sufficient conditions are developed to solve these problems, respectively. The expressions of desired state feedback fuzzy controllers are given. Finally, a numerical simulation is given to illustrate the effectiveness of the proposed method.

关键词： Fuzzy control H-infinity control Singular systems Stochastic stability Linear matrix inequality (LMI)

Output Rate of Atomic Four-Wave Mixing in Two-Component Bose-Einstein Condensate

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Communications in Theoretical physics 2004年第5期41卷 695-698页

作者： LI Jia-Hua~1 LI Wei-Bing~1 PENG Ju-Cun~2 1 department of physics,huazhong university of science and technology,wuhan 430074,china2.department of physics,Xiaogan Normal university,Xiaogan 432100,china department of physics Xiaogan Normal University Xiaogan 432100 China

In this letter,following the proposal of Heurich et al.[***.A63(2001)033605],we analyze anddiscuss output rate of atomic four-wave mixing in the two-component Bose-Einstein condensate under the condition ofthe steady *** results show that the magnitude of the signal beam increases with the increase of the intensityof the probe beam,up to a saturated value,then it decreases as the probe beam *** influence of theinteraction range on the signal beam is also *** particular,it is worth while pointing out that in contrast tothe previous solutions,our obtained analytical solutions are of very simple and explicit forms,which open the door forfurther investigating the related physical mechanisms.

关键词： atomic four-wave mixing steady state Bose-Einstein condensate

Image interpretation of weak-coupling N-mer adsorbate's STM system

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Chinese science Bulletin 1997年第5期42卷 371-374页

作者： HUANG Xintang, Ql Shouren, LI Xinjiao and LI Yongping1 department of physics, Central china Normal university, wuhan 430070, china department of Solid State Electronics, huazhong university of science and technology, wuhan 430074, china 2. department of physics, university of science and technology of china, Hefei 230026, china department of physics Central China Normal University Wuhan China department of Solid State Electronics Huazhong University of Science and Techndogy Wuhan China department of physics University of Science and Technology of China Hefei China

Up to now, there have been many indistinctive points in the image interpretation of scanning tunnelhng microscopy (STM) system, and the problems have attracted almost all STM scientists’ attention. In 1992, Kenkre proposed the new programme which describes the behaviour of the electrons moving in the STM tunnelling by the method of exciton dynamics, and the programme not only breaks through the restrictions of Tersoff-Hamann theory, but also can be applied conveniently to discussing the effects of the tip structure, adsorbate structure, substrate structure, temperature, tunneling voltage, and the degree of coherence of elec-

关键词： weak-coupling N-mer adsorbates STM image interpretation exciton dynamics method.

PEM:a lightweight program memory encryption mechanism for embedded processor

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The Journal of china Universities of Posts and Telecommunications 2010年第1期17卷 77-84页

作者： HUO Wen-jie,LIU Zheng-lin,ZOU Xue-cheng department of Electronics of science and technology,huazhong university of science and technology,wuhan 430074,china [a] department of Electronics of science technology Huazhong University of Science technology Wuhan 430074 China

Application of embedded systems is faced with multiple threats against security. To solve this problem, this article proposes a new program memory encryption mechanism （PEM） to enhance the security of embedded processor. The new mechanism encrypts all the programs via a secure cache structure. It not only caches the instructions read from the off-chip memory, but also stores the pad values used to encrypt the plaintext. It effectively accelerates encryption and reduces the performance overhead. Besides the encryption, PEM also monitors the program modifications and reset behaviors to reduce the risk of vicious tamper. The experiment indicates that PEM has an average of 2.3 % performance improvement and results in a 25.71% power reduction in the write-back stage. The new scheme offers a good balance between performance and security. It is fully practicable for embedded processor.

关键词： embedded processor memory encryption advanced encryption standard (AES) secure cache hardware protection