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A numerical study on nonlinear propagation and short-term variability of the migrating diurnal and semidiurnal tides

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Chinese Science Bulletin 2005年第17期50卷 1940-1948页

作者： HUANG Chunming1,2. zhang Shaodong1,2.& YI Fan1,2.1. {2. of Electronic Information,{2. Universiy, wuhan 430079, china 2. Key Laboratory of Geospace Environment and Geodesy, Ministry of Education, wuhan university, wuhan 430079, china school of Electronic Information Wuhan Universiy Wuhan China Key Laboratory of Geospace Environment and Geodesy Ministry of Education Wuhan University Wuhan China

By using a three-dimensional fully nonlinear numerical model in spherical coordinates and taking the linear steady solutions of the migrating diurnal and semidi-urnal tides in January from the Global-Scale Wave Model (GSWM) as the initial values, we simulate the linear and nonlinear propagations of the migrating diurnal and semidi-urnal tides in the atmosphere from the ground to the lower thermosphere. A comparison of our simulations with the results of GSWM is also presented. The simulation results show that affected by the nonlinearity, the migrating diurnal and semidiurnal tides propagating in the middle and upper atmosphere exhibit evident short-term variability. The nonlinear interactions between the migrating tides and the background atmosphere can obviously alter the background wind and temperature fields, which suggests that the nonlin-ear propagations of the migrating diurnal and semidiurnal tides impact significantly on the transient dynamical and thermal structures of the background middle and upper at-mosphere and the nonlinear effect is an important cause of the difference between the results of GSWM and observa-tions.

关键词：大气非线性传播数学模型可变性温度场

Evaluation Method of Web Site Structure Based on Web Structure Mining

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wuhan university Journal of Natural Sciences 2003年第3A期8卷 791-796页

作者： Li Jun\|e 1 , Zhou Dong\|ru 2.1. computer Center,{{2.{2., {{2. 43007{2. Hubei, china {2. school of computer,{{2.{2., {{2. 43007{2. Hubei,china computer Center Wuhan University Wuhan Hubei China school of computer Wuhan University Wuhan Hubei China

The structure of Web site became more complex than before. During the design period of a Web site, the lack of model and method results in improper Web structure, which depend on the designer's experience. From the point of view of software engineering, every period in the software life must be evaluated before starting the next period's work. It is very important and essential to search relevant methods for evaluating Web structure before the site is completed. In this work, after studying the related work about the Web structure mining and analyzing the major structure mining methods (Page\|rank and Hub/Authority), a method based on the Page\|rank for Web structure evaluation in design stage is proposed. A Web structure modeling language WSML is designed, and the implement strategies for evaluating system of the Web site structure are given out. Web structure mining has being used mainly in search engines before. It is the first time to employ the Web structure mining technology to evaluate a Web structure in the design period of a Web site. It contributes to the formalization of the design documents for Web site and the improving of software engineering for large scale Web site, and the evaluating system is a practical tool for Web site construction.

关键词： web structure mining page\|rank web structure evaluation modeling language for web structure

Progress in technology for the 2.05 height determination of Qomolangma Feng (Mt. Everest)

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Science china Earth Sciences 2006年第5期49卷 531-538页

作者： CHEN Junyong1,2. YUAN Janli1,2. GUO Chunxi1,2. zhang Yanping1 & zhang Peng1,{2.. State Bureau of Surveying and Mapping, Beijing 100830,{2. 2. school of Geodesy and Geomatics, wuhan university, wuhan 430079,{2. State Bureau of Surveying and Mapping Beijing China school of Geodesy and Geomatics Wuhan University Wuhan China

In 2.05 china carried out a new geodetic campaign for the height determination of Qo- molangma Feng——Mt. Everest (QF in short). The technical progresses in geodesy for the 2.05 campaign are presented in the paper. GPS positioning was the key technique in the campaign. After summarizing the experiences and lessons of the GPS positioning on the QF summit in the previous QF height determination campaigns, some measures were taken to raise the accuracy and reliability of the height determination with GPS techniques. In order to raise the accuracy of the height deter- mination of the QF summit with classical geodetic techniques, laser ranging was used together with the trigonometric levelling in the 2.05 campaign. It is the first time in china the thickness of the ice-snow layer on the QF summit was measured by ground penetrating radar integrated with GPS. The local gravity field and geoid in the QF area was improved on the basis of earth gravity field model integrated with new ground gravity data, DTM data and GPS leveling data in the QF area. In the 2.05 campaign the normal height and orthometric height (height above sea level) of the snow surface of the QF summit were obtained as 8846.67 m and 8847.93 m respectively. The orthometric height of the rock surface of the QF summit is 8844.43 m,and the thickness of the ice-snow layer on the QF summit is 3.50 m.

关键词： Qomolangma Feng, Mt. Everest, height determination, GPS, gravity field, ground penetrating radar.

Accountability Analysis of Electronic Commerce Protocols by Finite Automaton Model

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wuhan university Journal of Natural Sciences 2004年第3期9卷 293-295页

作者： Xie Xiao-yao 1,2., zhang Huan-guo 1 1. {2. of{2., wuhan university, wuhan 430072. Hubei, china 2. Institute of Network Technology, Guizhou university of Technology, Guiyang 550003, Guizhou, china school of computer Wuhan University Wuhan Hubei China Institute of Network Technology Guizhou University of Technology Guiyang Guizhou China

The accountability of electronic commerce protocols is an important aspect to insures security of electronic transaction. This paper proposes to use Finite Automaton (FA) model as a new kind of framework to analyze the transaction protocols in the application of electronic commerce. Key words finite automaton - electronic commerce - nonrepudiation - information security CLC number TP 393. 08 Foundation item: Supported by the National Natural Science Foundation of china (66973034, 90104005, 60373087)Biography: Xie Xiao-yao (1952.), male, Professor, Ph. D candidate, research direction: information security.

关键词： finite automaton electronic commerce nonrepudiation information security

Commission Strategy of the Auction House

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wuhan university Journal of Natural Sciences 2006年第3期11卷 507-510页

作者： WANG Yan~ 1,2.1. College of Economics, Fudan university, Shanghai {2.0433,{{2. {2.{2. of Mathematics and Statistics, wuhan university , wuhan 43007{2. Hubei,{{2. College of Economics Fudan University Shanghai China school of Mathematics and Statistics Wuhan University Wuhan Hubei China

In a SIPV model, when the commission proportion is not certain, but related with bargain price, generally, it is a linear function of the bargain price, this paper gives bidders＇ equilibrium bidding strategies in the first-and secondprice auctions. We find that the equilibrium strategies in second-price auction are dominant strategies. For seller or auction house, whether the fixed proportion or the unfixed proportion is good is not only related with constant item and the linear coefficient of the linear function, the size of the fixed commission proportion, but also related with the value of the item auctioned. So, in the practical auctions, the seller and the auction house negotiated with each other to decide the commission rules for their own advantage.

关键词： auction commission proportion Bayesian equilibrium bidding strategy

A Hybrid Genetic Algorithm for Reduct of Attributes in Decision System Based on Rough Set Theory

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wuhan university Journal of Natural Sciences 2002年第3期7卷 285-289页

作者： Dai Jian\|hua 1,2., Li Yuan\|xiang 1,2.,Liu Qun 3 1. State Key Laboratory of Software Engineering,{2., wuhan 430072. Hubei,{2. 2. school of computer,{2., wuhan 430072. Hubei,{12. 3. school of computer Science, Lab. of Software Eng. Wuhan Univ. Wuhan 430072 China Sch. of Comp. Wuhan Univ. Wuhan 430072 China Sch. of Comp. Sci. Chongqing Univ. of Post and Telecom. Chongqing 400065 China

Knowledge reduction is an important issue when dealing with huge amounts of data. And it has been proved that computing the minimal reduct of decision system is NP-complete. By introducing heuristic information into genetic algorithm, we proposed a heuristic genetic algorithm. In the genetic algorithm, we constructed a new operator to maintaining the classification ability. The experiment shows that our algorithm is efficient and effective for minimal reduct, even for the special example that the simple heuristic algorithm can’t get the right result.

关键词： rough set reduction genetic algorithm heuristic algorithm

A Principal Theorem of Normal Discretization Schemes for Operator Equations of the First Kind

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wuhan university Journal of Natural Sciences 2001年第4期6卷 767-768页

作者： Du Nai lin 1, Wang Hannah 2.1.school of Mathematics and Statistics,{{2.,{2. 43007{2. china {2. school of Foreign Languages and Literature,wuhan university,wuhan 43007{2.{12. school of Mathematics and Statistics Wuhan University Wuhan China school of Foreign Languages and Literature Wuhan University Wuhan China

The authors announce a newly-proved theorem of theirs. This theorem is of principal significance to numerical computation of operator equations of the first kind.

关键词： operator equation of the first kind normal discretization scheme pure pseudoinverse

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. The Key Laboratory of Aerospace Information Security and Trusted Computing, Ministry of Education,{2. of computer, wuhan university, wuhan 430079, china 2.State Key Laboratory of Software Engineering, wuhan university, wuhan 430072. china The Key Laboratory of Aerospace Information Security and Trusted Computing Ministry of Education School of Computer Wuhan University Wuhan China State Key Laboratory of Software Engineering Wuhan University Wuhan 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

Hierarchical Classification of Chinese Documents Based on N grams

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wuhan university Journal of Natural Sciences 2001年第Z1期6卷 416-422页

作者： Zhou Shui geng 1, Guan Ji hong 2. He Yan xiang 2.1. State Key Laboratory of Software Engineering,{2., {2. 430072.{2. 2. school of computer Science,{2., {2. 430072.{2. State Key Laboratory of Software Engineering Wuhan University Wuhan China school of computer Science Wuhan University Wuhan China

We explore the techniques of utilizing N gram information to categorize Chinese text documents hierarchically so that the classifier can shake off the burden of large dictionaries and complex segmentation processing, and subsequently be domain and time independent. A hierarchical Chinese text classifier is implemented. Experimental results show that hierarchically classifying Chinese text documents based N grams can achieve satisfactory performance and outperforms the other traditional Chinese text classifiers.

关键词： Chinese text classification N grams feature selection hierarchical classification