检索结果-南通市图书馆

Research and Development of an Embedded Numerical Control System

在线全文

学校读者我要写书评

暂无评论

武汉理工大学学报 2006年第S3期28卷 1121-1124页

作者： zhang Jinhuan school of Information Engineering,wuhan university of Technology,wuhan 430070,china, school of Information Engineering Wuhan University of TechnologyWuhan 430070China

This paper puts forward a new scheme of Embedded Numerical Control System based on ARM and DSP,which is at the base of research on traditional numerical control system and embedded *** the paper also describes the develop- ment of hardware and software *** the development and realization are based on the idea of module *** embed- ded numerical control system,using ARM and DSP to construct the main control platform,realizes the real-time operation of sys- tem and improves the stability and reliability with the modular designing ideas of hardware and software and with the support of embedded real-time operating system(uc/os-Ⅱ).And the system could realize the multi-network supporting,which is also accord with the development of modularization,flexibility and latticing of numerical control system.

关键词： real-time operating system embedded technology numerical control system ARM DSP

Vapor Online Monitor Model of Vapor Power Station Based on UML

在线全文

学校读者我要写书评

暂无评论

wuhan university Journal of Natural Sciences 2001年第4期6卷 775-778页

作者： Jin Ye, Tang Xu\|zhang, Yu Jun\|qing, Zhou Dong\|ru school of Computer, wuhan university, wuhan 430072, china wuhan university School of Computer Wuhan China (GRID:grid.49470.3e) (ISNI:***)

We presents a vapor online monitor system model of vapor power station developed by visual tool rational rose 2000. Use cases such as on line instrument (onlineinstr), control, query, report, real database (realdb) and alarm are generated according to the system requirements. Use case view and class view of the system are formed at the same time. As for all the UML models of the system, this paper focuses the discussion on the class view, the component diagram of the control class and the sequence diagram of the query class. Corresponding C++ codes are produced and finally transferred into the spot running software.

关键词： online monitor model UML

Non-metallic Inclusions in Continuously Cast Aluminum Killed Steels

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2000年第3期14卷 193-196页

作者： Wenjun Wang, Xinhua Wang, Jiongming zhang, Wanjun Wang, Youyu Zhou ( Metallurgy school, university of Science and Technology Beijing, Beijing 100083, china Steelmaking Research Institute, wuhan Iron and Steel Group, wuhan 430080, china) Metallurgy school University of Science and Technology Beijing Beijing 100083 China Steelmaking Research Institute Wuhan Iron and Steel Group Wuhan 430080 China

In aluminum killed steels, the size, shape, quantity and formation of non-metallic inclusions in ladle steel (before and after RH vacuum treatment) and in tundish as well as in slabs were studied by EPMA (Electron Probe Microanalysis) and by analyzing the total oxygen. The results showed that in the slabs the total oxygen was quite low and the inclusions discovered were mainly small-sized angular alumina inclusions. This indicates that most inclusions have been removed by floating out during the continuous casting process. In addition, the countermeasures were discussed to decrease the alumina inclusions in the slabs further.

关键词： aluminum killed steel non-metallic inclusion alumina continuous casting

Evolutionary cryptography against multidimensional linear cryptanalysis

在线全文

学校读者我要写书评

暂无评论

Science china(Information Sciences) 2011年第12期54卷 2585-2597页

作者： zhang HuanGuo 1,2 , LI ChunLei 1,2 & TANG Ming 1,2 1 school of Computer, wuhan university, wuhan 430079, china 2 Key Laboratory of Aerospace Information Security and Trusted Computing of Ministry of Education of china, wuhan university, wuhan 430079, china 1. school of Computer Wuhan University Wuhan 430079 China2. Key Laboratory of Aerospace Information Security and Trusted Computing of Ministry of Education of China Wuhan University Wuhan 430079 China

The evolutionary cryptosystem is a new cryptosystem proposed by a Chinese researcher recently. This paper studies its security level resisting against multidimensional linear cryptanalysis in this paper. It is shown that the evolutionary cryptosystem possesses higher resistance than its initial fixed cryptosystem does for resisting against multidimensional linear cryptanalysis. Multidimensional generalizations of Matsui's Algorithm 1 and Algorithm 2 based on log-likelihood ratio (LLR) statistics are introduced. By the relationship among the data complexity N , the bit advantage a and the success rate P S of these two multidimensional generalized algorithms, it is proven that more data is needed for attacking the evolutionary cryptosystem than that is needed for attacking its initial fixed cryptosystem when the bit advantage and success rate are identical. Moreover, it is shown that both time complexity and memory complexity for attacking the evolutionary cryptosystem are higher than that of attacking its initial fixed cryptosystem with the same data complexity. The research indicates that the evolutionary cryptosystem is more robust than its initial fixed cryptosystem against the multidimensional linear cryptanalysis.

关键词： information security cryptology evolutionary cryptosystem cryptanalysis multidimensional linear cryptanalysis

A PARALLEL NUMERICAL MODEL OF SOLVING N-S EQUATIONS BY USING SEQUENTIAL REGULARIZATION METHOD

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2003年第1期15卷 72-77页

作者： Project supported by the National Natural Science Foundation of china. (Grant No:69773021)zhang She sheng, Zou Zao jian, Xiang Ping bo school of Science, wuhan university of Technology, wuhan 430063, china school of Science Wuhan University of Technology Wuhan 430063 China

A parallel numerical model was established for solving the Navier-Stokesequations by using Sequential Regu-larization Method (SRM). The computational domain is decomposedinto P sub-domains in which the difference formulae were obtained from the governing equations. Thedata were exchannged at the virtual boundary of sub-domains in parallel computation. Theclose-channel cavity flow was solved by the implicit method. The driven square cavity flow wassolved by the explicit method. The results were compared well those given by Ghia.

关键词： parallel computer sequential regularization method (SRM)

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

在线全文

学校读者我要写书评

暂无评论

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,Huazhong Normal university,wuhan 430079,Hubei,china 2.school of Mathematics and Statistics, wuhan university, wuhan 430072, Hubei, china 3.Faculty of Science,Ningbo university,Ningbo 315211,Zhejiang, china Huazhong Normal university School of Mathematics and Statistics Wuhan Hubei China (GRID:grid.411407.7) (ISNI:***) wuhan university School of Mathematics and Statistics Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***) Ningbo university Faculty of Science Ningbo Zhejiang China (GRID:grid.203507.3) (ISNI:***)

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

SOME BOUNDARY INCREASING PROPERTIES OF HARMONIC FUNCTIONS IN LIPSCHITZ DOMAIN

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 1996年第2期17卷 159-166页

作者： zhang YIPING Department of Mathematics, wuhan university, wuhan 430072, china.Project supported by the National Natural Science Foundation of china. wuhan UNIV DEPT MATH WUHAN 430072 PEOPLES R CHINA

The object of this paper is to study the non-tangential increasing properties of positiveharmonic function u in Lipschitz domain by means of Martin representation theory. A necessaryand sufficient condition of the control of growth of u near any fixed boundary point is obtained.It is shown that the non-tangential increasing degree of u near a boundary point is exactlythe local degree of its representation measure with respect to the harmonic measure. Someexamples are given.

关键词： Martin representation Harmonic function Harmonic measure

Carbon Solubility and Mass Action Concentrations of Fe-Cr-C Melts

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2000年第2期14卷 86-91页

作者： Jtan zhang(Metallurgy school, university of Science and Technology Beijing, Beijing 100083, china) Metallurgy school University of Science and Technology Beijing Beijing 100083 China

An empirical equation of carbon solubility in Fe-Cr-C melts is regressed based on the experimental data from references. Acalculating model of mass action concentrations for these melts is formulated on the basis of the coexistence theory of metaIlic melts in-volving compound formation, the phase diagram of Cr-C system as well as thermodynamic data of Fe-Cr-C melts. According to the mod-el, the standard Gibbs free energies of formation of CrC and Cr3C2 are obtained. Satisfactory agreement between the calculated and me-asured values shows that the model can reflect the structural characteristics of Fe-Cr-C melts.

关键词： activity, coexistence theory mass action concentration saturated state

Applicability of mass action law to sulphur distribution between slag melts and liquid iron

在线全文

学校读者我要写书评

暂无评论

Journal of university of Science and Technology Beijing 2002年第2期9卷 90-98页

作者： Jian zhang Metallurgy school, university of Science and Technology Beijing, Beijing 100083, china Metall. Sch. Univ. of Sci. and Technol. Beijing Beijing 100083 China

According to the mass action law and the coexistence theory of slagstructure, the calculating models of mass action concentration for CaO-MgO-FeO-Fe_2O_3-SiO_2,CaO-MgO-MnO-FeO-Fe_2O_3-P_2O_5-SiO_2 and CaO-MgO-MnO-FeO-Fe_2O_3-Al_2O_3-P_2O_5-SiO_2 slag melts areformulated and sulphur distribution between the slag melts and liquid iron is treated. It is foundthat CaO, MnO and FeO promote desulphurization, while MgO is detrimental to desulphurization. Inaddition, the sulphur distribution coefficients between the slag melts and liquid iron andpresented.

关键词： mass action law coexistence theory of slag structure activity massaction concentration