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A Note on Abelian Extensions

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wuhan university Journal of Natural Sciences 2008年第1期13卷 6-8页

作者： YU Chuxiong1,2, FAN Yun3.1. school of mathematics and statistics,{3. university,{3. 43.072, hubei, China 2. school of mathematics and Computer Science, Jianghan university,{3. 43.056, hubei, China 3. school of mathematics and statistics,{13., wuhan 43.079, hubei, China school of mathematics and statistics Wuhan University Wuhan China school of mathematics and Computer Science Jianghan University Wuhan China school of mathematics and statistics Huazhong Normal University Wuhan China

Let K/Q be any abelian extension where Q is the field of rational numbers. By Galois theory and the Frobenius formula for induced characters, we prove that there exists a metabelian group G and an irreducible characte... 详细信息

关键词： abelian extensions metabelian groups induced characters Galois groups

Criteria for Regularity of Elliptic Diffusion Processes and It’s Application

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wuhan university Journal of Natural Sciences 2005年第2期10卷 347-350页

作者： LI Bo 1,2 , ZHANG Xiao-min 3.1.school of mathematics and statistics,{3. normal university,wuhan 43.079,hubei,China 2.school of mathematics and statistics, wuhan university, wuhan 43.072, hubei, China 3.Faculty of Science,Ningbo university,Ningbo 3.5211,Zhejiang, China school of mathematics and statistics Huazhong Normal University Wuhan Hubei China school of mathematics and statistics Wuhan University Wuhan Hubei China Faculty of Science Ningbo University Ningbo Zhejiang China

The cone condition for x to be tegular for B under the elliptic diffusionprocess was proved. We also gave a necessary and sufficient condition for 0 to be regular for thornunder the elliptic diffusion process.

关键词： regular capacity thorn diffusion process

Statistical Inference for Simple Tree Order in the Means of Stochastic Order on Stratified Contingency Tables

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wuhan university Journal of Natural Sciences 2010年第2期15卷 93-98页

作者： YAN Guoyi1,2, CHEN Jingjing3.1.school of mathematics and statistics,{3. university,{3. 43.072, hubei, China 2. school of Sciences,{3. Institute of Technology,{3. 43.074, hubei, China 3. school of Sciences,{3. university of Science and Technology,{3. 43.081, hubei, China school of mathematics and statistics Wuhan University Wuhan China school of Sciences Wuhan Institute of Technology Wuhan China school of Sciences Wuhan University of Science and Technology Wuhan China

In this paper, we consider testing the hypothesis that all multinomial populations in the stratified contingency table are identically distributed against the alternative that all these popula- tions are in simple tree order. We provide an asymptotic represen- tation of the order-restricted maximum likelihood estimate of the unknown parameters. The resulting estimators are proven to be ~n-consistent and asymptotically normal under appropriate conditions. A chi-squared test method is used for this hypothesis test problem. A real data set is applied to illustrate our theoretical result.

关键词： simple tree order chi-squared test asymptotic representation asymptotic distribution

11-Round Impossible Differential Algebraic Attack for Serpent Encryption Algorithm

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wuhan university Journal of Natural Sciences 2010年第3期15卷 232-236页

作者： HU Zhihua1,2, QIN Zhongping3.1. school of Computer, wuhan university, wuhan 43.072, hubei, China 2. College of Mathematical and Information Sciences,Huanggang normal university, Huanggang 43.000, hubei, China 3. school of Software Engineering, huazhong university of Science and Technology, wuhan 43.074, hubei, China school of Computer Wuhan University Wuhan Hubei China College of Mathematical and Information Sciences Huanggang Normal University Huanggang Hubei China school of Software Engineering Huazhong University of Science and Technology Wuhan Hubei China

This paper explored algebraic features of nonlinear parts in Serpent encryption algorithm and offered an 11-round Serpent-128 impossible differential algebraic attack through utilizing the method in constructing S-box algebraic equations. The new method analyzed block ll-round Serpent with 2127 selected plaintexts and 2-29 bytes memory space at the same time of giving a new design principle of S-box anti-algebraic attack.

关键词： impossible differential Serpent algebraic equation

Energy Efficient Beacon Discovering Scheme for Node Localization in Wireless Sensor Networks

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wuhan university Journal of Natural Sciences 2010年第4期15卷 303-307页

作者： LIU Xinxin1,2, ZHAO Erdun3. CHEN Kun2 1. school of Computer, wuhan university, wuhan 43.072, hubei, China 2. wuhan Digital Engineering Research Institute, wuhan 43.074, hubei, China 3. Department of Computer Science, huazhong normal university, wuhan 43.079, hubei, China school of Computer Wuhan University Wuhan Hubei China wuhan Digital Engineering Research Institute Wuhan Hubei China Department of Computer Science Huazhong Normal University Wuhan Hubei China

Efficient sensor node localization is a crucial part of many location-dependent applications that utilize wireless sensor networks (WSNs). To cope with the problem of insufficient bea-con node for localization,we design a beacon discovery protocol in this paper that helps the blind node to find beacons nearby and present an energy efficient scheme for the beacon that receives the request from a blind node to adjust its radio range. We obtain the relationship between the mean energy consumption with adjust-ment number by the mathematical analysis. Numerical results show that great energy saving is achieved when the optimal ad-justment number is adopted.

关键词： localization wireless sensor networks energy- efficient radio range adjustment

UNIFORM ESTIMATE ON FINITE TIME RUIN PROBABILITIES WITH RANDOM INTEREST RATE

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Acta Mathematica Scientia 2010年第3期30卷 688-700页

作者：明瑞星何晓霞胡亦钧刘娟 school of mathematics and Information Sciences Jiangxi Normal University school of mathematics and statistics Wuhan University College of Science Wuhan University of Science and Technology College of mathematics and statistics Hubei Normal University

We consider a discrete time risk model in which the net payout （insurance risk） {Xk, k = 1, 2,...} are assumed to take real values and belong to the heavy-tailed class L∩ D and the discount factors （financial risk） {Yk, k = 1,2,...} concentrate on [θ, L], where 0 〈 0 〈 1, L 〈 ∞, {Xk, k = 1,2,...}, and {Yk, k=1,2,...} are assumed to be mutually independent. We investigate the asymptotic behavior of the ruin probability within a finite time horizon as the initial capital tends to infinity, and figure out that the convergence holds uniformly for all n ≥ 1, which is different from Tang Q H and Tsitsiashvili G （Adv Appl Prob, 2004, 3.： 1278-1299）.

关键词： Random interest rate finite time ruin probability uniformity

normal scalar curvature and a pinching theorem in S^m×R and H^m×R

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Science China mathematics 2011年第9期54卷 1977-1984页

作者： CHEN Qun 1,2 & CUI Qing 3.1,1 school of mathematics and statistics,{3. university,{3. 43.079,China 2 International Center for Theoretical Physics,Trieste 3.100,Italy 3.school of mathematics,Southwest Jiaotong university,Chengdu 61003.,China school of mathematics and statistics Wuhan University Wuhan China International Center for Theoretical Physics Trieste Italy school of mathematics Southwest Jiaotong University Chengdu China

We obtain an inequality in Sm×R and Hm×R which is similar to DDVV *** an application,we show that a minimal submanifold in H m×R with nonnegative scalar curvature must be a surface of the type γ×R,where γ is a g... 详细信息

关键词： product spaces DDVV conjecture pinching theorem

COMPLETE HYPERSURFACES WITH CONSTANT MEAN CURVATURE AND FINITE INDEX IN HYPERBOLIC SPACES

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Acta Mathematica Scientia 2011年第1期31卷 353-360页

作者：邓勤涛 Department of mathematics Sun Yat-Sen University Laboratory of Nonlinear Analysis and School of Mathematics and StatisticsHuazhong Normal University

In this article, we prove that any complete finite index hypersurface in the hyperbolic space H4（-1）（H5（-1）） with constant mean curvature H satisfying H2 663. （H2 114785 respectively） must be compact. Specially, we verify that any complete and stable hypersurface in the hyperbolic space H4（-1）（resp. H5（-1）） with constant mean curvature H satisfying H2 6643.（resp. H2 114785 ） must be compact. It shows that there is no manifold satisfying the conditions of some theorems in [7, 9].

关键词： k-weighted bi-Ricci curvature finite index constant mean curvature

A Graph Theoretic Method to Handle Deadlocks in Flexible Manufacturing Cells

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武汉理工大学学报 2006年第S3期28卷 1117-1120页

作者： WANG Chunxiang~(1,2) LIU Donglin~3.(1.school of mathematics and statistics,{3. university,{3. 43.072,China, 2.school of mathematics and statistics,Central China normal university,{3. 43.079,China 3.school of Electronic and Mechanical Engineering,{3. university of Technology,{3. 43.070,China) school of mathematics and statistics Wuhan UniversityWuhan 430072China school of mathematics and statistics Central China Normal UniversityWuhan 430079China school of Electronic and Mechanical Engineering Wuhan University of TechnologyWuhan 430070China

The deadlock-handling scheme is based on a bipartite graph model of the part-machine relationship in the manufac- turing cell.A distinction is made between permanent deadlock and transient *** deadlock depicts a manufactur- ing system state where parts are irrevocably blocked and where external intervention is required to resolve the deadlock,whereas a transient deadlock indicates that there is a positive probability that the deadlock will resolve itself over *** recover from dead- locks,one control policy is studied:resolve deadlocks in the manufacturing *** the policy,it is shown that it is sufficient to resolve any cycle in the set of deadlocked parts to resolve the ***,we estimate the deadlocks in flexible manufactur- ing cells.

关键词： permanent deadlock transient deadlock deadlock detection deadlock resolution graph