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The Numerical Method of Inversion for the Interior radon Transform

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wuhan univ.rsity Journal of Natural sciences 2000年第2期5卷 143-146页

作者： WANG Jin ping, DU Jin yuan College of Mathematics and computer science, wuhan univ.rsity ,wuhan 430072, china wuhan univ.rsity College of Mathematics and Computer Science Wuhan China (GRID:grid.49470.3e) (ISNI:***)

The interior radon transform arises from a limited data problem in computerized tomography. The corresponding operator r is investigated as a mapping between wightedL 2-spaces. Our result is the explicit construction of a singular value decomposition for r. This immediately leads to an inversion formula by series expansion and range characterizations.

关键词： Key words the interior radon transform eigenproblem inversion

THEOrETICAL ANALYSIS AND NUMErICAL SIMULATION OF TUrBULENT FLOW ArOUND SAND WAVES AND SAND BArS

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Journal of Hydrodynamics 2009年第2期21卷 292-298页

作者： LIU Shi-he XIONG Xiao-yuan LUO Qiu-shi State Key Laboratory of Water resource and Hydropower Engineering science Wuhan University Wuhan 430072 China school of Water resource and Hydropower Wuhan University Wuhan 430072 China Changjiang river Administration of Navigation Affairs MC Wuhan 430014 China

Natural rivers usually possess sand waves and sand bars. In this article, the rapid distortion theory was used to study the turbulent flow over sand waves. The results show that the pre-existing sheafing motion and upstream anisotropy of the turbulence flow would have significant effect on the turbulent structures, and hence the memory effect should be taken into consideration. Furthermore, the 2-D mathematical model was employed to simulate the unsteady flow around the Taiping Sand Bar in the lower reach of the Yangtze river and the time step effect on the unsteady flow simulation with the implicit scheme was discussed at the same time. The results show that the implicit scheme keeps effective until the time step reaches a certain number, and the calculated water levels and velocities are in agreement with the observed data.

关键词： sand wave sand-bar rapid distortion theory numerical simulation

A Fast pseudorandom Number Generator with BLAKE Hash Function

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wuhan univ.rsity Journal of Natural sciences 2010年第5期15卷 393-397页

作者： WANG Houzhen1,2,ZHANG Huanguo1,2 1.Key Laboratory of Aerospace Information Security and Trusted Computing of Ministry of Education,wuhan univ.rsity,wuhan 430072,Hubei,china 2.school of computer,wuhan univ.rsity,wuhan 430072,Hubei,china Key Laboratory of Aerospace Information Security and Trusted Computing of Ministry of Education Wuhan University Wuhan Hubei China school of computer Wuhan University Wuhan Hubei China

This paper presents a fast pseudorandom generation algorithm,which is based on the BLAKE hash function and can pass the random test of the NIST（National Institute of Standards and Technology） Statistical Test *** theoretical analysis and experimental imitation,our new algorithm is proven to be more secure and efficient than ***,we introduce and discuss the BLAKE in *** security shows that can be utilized to generate pseudorandom bit sequences,which the experimental results show the BLAKE hash function has excellent ***,we believe the BLAKE is one of the most potential candidate algorithms of SHA-3 program.

关键词： cryptography pseudorandom number generator hash function National Institute of Standards and Technology Statistical Test Suite

A Design Method of Business Application Framework Based on Software patterns

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wuhan univ.rsity Journal of Natural sciences 2001年第Z1期6卷 204-208页

作者： He Ke\|qing 1, Yang Chun wen 1, Ying Shi 2 1. school of computer science, wuhan univ.rsity, wuhan 430072, china 2. State Key Laboratory of Software Engineering, wuhan univ.rsity, wuhan 430072, china school of computer science Wuhan University Wuhan 430072 China

This paper discusses design and implementation method of Business Application Framework based on software patterns, and then presents MVC pattern of architecture and the method of dynamical update promulgation for Business Application Framework. We discuss adaptation of Abstract Factory for the kernel functionality of Business Application Framework, such as data creation, manipulation, composition, etc. It also presents class model and its class structure of Abstract Factory pattern. Finally, we briefly discuss the update, modification, and reconstruction method of Business Application Framework.

关键词： object oriented MVC pattern Abstract Factory pattern software framework UML role model

The construction of Markov processes in random environments and the equivalence theorems

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science china Mathematics 2004年第4期47卷 481-496页

作者： HU Diheschool of Mathematics and Statistics, wuhan univ.rsity, wuhan 430072, china 1. school of Mathematics and Statistics Wuhan University 430072 Wuhan China

In sec.1, we introduce several basic concepts such as random transition function, p-m process and Markov process in random environment and give some examples to construct a random transition function from a non-homogeneous density function. In sec.2, we construct the Markov process in random enviromment and skew product Markov process by p - m process and investigate the properties of Markov process in random environment and the original process and environment process and skew product process. In sec. 3, we give several equivalence theorems on Markov process in random environment.

关键词： radom transition function, p -m process, Markov process in random environment, skew product Markov process, density function.

Extended multivariate public key cryptosystems with secure encryption function

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science china(Information sciences) 2011年第6期54卷 1161-1171页

作者： WANG HouZhen 1,2 , ZHANG HuanGuo 1,2 , WANG ZhangYi 1,2 & TANG Ming 1,2 1 The Key Laboratory of Aerospace Information Security and Trusted Computing, Ministry of Education, school of computer, wuhan univ.rsity, wuhan 430079, china 2 State Key Laboratory of Software Engineering, wuhan univ.rsity, wuhan 430072, china 1. The Key Laboratory of Aerospace Information Security and Trusted Computing Ministry of Education School of Computer Wuhan University Wuhan 430079 China2. State Key Laboratory of Software Engineering Wuhan University Wuhan 430072 China

Advances in quantum computers pose great threats on the currently used public key cryptographic algorithms such as rSA and ECC. As a promising candidate secure against attackers equipped with quantum computational power, multivariate public key cryptosystems (MpKCs) have attracted increasing attention in recently years. Unfortunately, the existing MpKCs can only be used as a multivariate signature scheme, and it remains unknown how to construct an efficient MpKC enabling secure encryption. Furthermore, some multivariate signature schemes have been shown insecure in recent years, and it is also not trivial to build MpKC which can serve as a secure signature scheme. By employing the basic MQ-trapdoors, this paper proposes a novel MpKC and shows how it can be used as a multivariate signature scheme and a multivariate encryption scheme, respectively. The goal is achieved by incorporating our new hash authentication techniques and some modification methods such as the Shamir's minus method. Thorough analysis shows that our schemes are secure and efficient. Our MpKC gives a positive response to the challenges in multivariate public key cryptography.

关键词： cryptography post-quantum cryptography MQ problem hash function

A Semantic retrieval Method Based on the Fuzzy reasoning

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wuhan univ.rsity Journal of Natural sciences 2002年第2期7卷 169-173页

作者： Cao Jia-heng,Liu Juan,peng Min,Shu Feng-di school of computer,wuhan univ.rsity,wuhan 430072,Hubei, china wuhan univ.rsity School of Computer Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***)

This paper gives a semantic fuzzy retrieval method of multimedia object, discusses the principle of fuzzy semantic retrieval technique, presents a fuzzy reasoning mechanism based on the knowledge base, and designs the... 详细信息

关键词： Key words semantic retrieval fuzzy reasoning knowledge base multimedia object

CHArACTErIZATION OF rEGENErATED CELLULOSE MEMBrANES HYDrOLYZED FrOM CELLULOSE ACETATE

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Chinese Journal of polymer science 2002年第4期20卷 369-375页

作者： Yun Chen Xiao-peng Xiong Guang Yang Li-na Zhang Sen-lin Lei Hui Liang Electron Microscope Lab of Medical school, wuhan univ.rsity wuhan 430072, china College of Chemistry and Molecular sciences, wuhan univ.rsity, wuhan 430072, china wuhan univ Coll Chem & Mol Sci Wuhan 430072 Peoples R China wuhan univ Sch Med Electron Microscope Lab Wuhan 430072 Peoples R China

A series of cellulose acetate membranes were prepared by using formamide as additive, and then were hydrolyzed in 4 wt% aqueous NaOH solution for 8 h to obtain regenerated cellulose membranes. The dependence of degree of substitution, structure, porous properties, solubility and thermal stability on hydrolysis time was studied by chemical titration, Fourier transform infrared spectroscopy, scanning electron microscopy, wide-angle X-ray diffraction, and differential scanning calorimetry, respectively. The results indicated that the pore size of the regenerated cellulose membranes was slightly smaller than that of cellulose acetate membrane, while solvent-resistance, crystallinity and thermostability were significantly improved. This work provides a simple way to prepare the porous cellulose membranes, which not only kept the good pore characteristics of cellulose acetate membranes, but also possessed solvent-resistance, high crystallinity and thermostability. Therefore, the application range of cellulose acetate membranes can be expanded.

关键词： hydrolysis cellulose acetate thermal stability regenerated cellulose membrane pore size solvent-resistance SEM

rate of strong consistency of quasi maximum likelihood estimate in generalized linear models

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science china Mathematics 2004年第6期47卷 882-893页

作者： YUE Li & CHEN Xiru school of Mathematics and Statistics, wuhan univ.rsity, wuhan 430072, china Graduate school, Chinese Academy of sciences, Beijing 100039, china 1. school of Mathematics and Statistics Wuhan University 430072 Wuhan China 2. Graduate school Chinese Academy of Sciences 100039 Beijing China

Under the assumption that in the generalized linear model (GLM) the expectation of the response variable has a correct specification and some other smooth conditions, it is shown that with probability one the quasi-likelihood equation for the GLM has a solution when the sample size n is sufficiently large. The rate of this solution tending to the true value is determined. In an important special case, this rate is the same as specified in the LIL for iid partial sums and thus cannot be improved anymore.

关键词： quasi-likelihood function generalized linear models strong consistency