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Estimation on principal component of multi-collinearity Gauss-Markov model based on minimum description length

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中国有色金属学会会刊：英文版 2005年第S1期15卷 153-155页

作者： SHI Yu-feng~(1, 2. (1. Shandong university of Technology, Zibo 2.5049, china 2. {2. laboratory of Geospace Environment and Geodesy, ministry of education, wuhan university, wuhan 430079, china) Shandong Univ Technol Zibo 255049 Peoples R China wuhan Univ Minist Educ Key Lab Geospace Environm & Geodesy Wuhan 430079 Peoples R China

Gauss-Markov model is frequently used in data analysis; the analysis and estimation of its parameters is always a hot issue. Based on the information theory and from the viewpoint of optimal information on description—minimum description length, this paper discusses a case: where there is multi-collinearity in the coefficient matrix, principal component estimation is used to estimate and select the original parameters, so as to reduce its multi-collinearity and improve its credibility. From the viewpoint of minimum description length, this paper discusses the approach of selecting principal components and uses this approach to solve a practical problem.

关键词： minimum description length Gauss-Markov model multi-collinearity principal component estimation

MCM-41 Prepared with Ionic Liquid and Cethytrimethylammonium Bromide as Co-templates

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Journal of wuhan university of Technology(Materials Science) 2009年第1期24卷 25-29页

作者：张光旭 School of Chemical Engineering Wuhan University of Technology College of Chemistry and Molecular sciences Wuhan University

The mesoporous molecular sieves MCM-41 were prepared using room tempera-ture ionic liquid （RTIL） synthesized in laboratory and cethytrimethylammonium bromide （CTAB） as compound templates for the first time. They were prepared under low aging temperature and short aging time. Via characterizing by XRD and nitrogen adsorption instrument, MCM-41 synthesized by this new method exhibited good crystal structure and narrow pore distribution. The following pre-paratory conditions was optimal： the molar ratio of RTIL to CTAB was 1.0∶1.0, aging at 80 ℃, for 40 h and calcined at 540 ℃. It is found that the acidified MCM-41 improves its activity as catalyst over the unmodified ones.

关键词： mesoporous molecular sieve hydrothermal crystallization co-templates ionicliquid MCM-41

Node ordinal encoded genetic algorithm for the optimal allocation of water resources

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Progress in Natural Science:Materials International 2005年第5期15卷 448-452页

作者： YANG Xiaohua1*, YANG Zhifeng 1,2. SHEN Zhenyao1 and LI Jianqiang3(1. State key laboratory of Water Environment Simulation, School of Environment, Beijing Normal {2., Beijing 100875, china 2. key laboratory for Water and Sediment Sciences ministry of education, School of Environment, Beijing Normal {2., Beijing 100875, china 3. Water resources and Hydropower Planning and Design General Institute, MWR, Beijing 100011, china) State key Lab. of Water Environ. Simulation Sch. of Environ. Beijing Normal Univ. Beijing 100875 China key Lab. for Water and Sediment Sci. Min. of Edu. Sch. of Environ. Beijing Normal Univ. Beijing 100875 China Water resources and Hydropower Planning and Design General Inst. MWR Beijing 100011 China

A new method, node ordinal encoded genetic algorithm (NOEGA), is proposed for solving water resources optimal allocation problems, in which the capacity of water resources is split into a number of smaller parts so that successive operations can be overlapped. Our objective is to maximize the whole benefit function. To overcome the “dimensionality and algorithm complexity curse” while searching for solutions and looking for an optimal solution, the operations of one-point crossover operator, gene exchange operator, gene random operator, gene shift operator and node ordinal strings are established. It is proved to be an effective optimal method in searching for global solutions. The NOEGA does not need a diversity of initial population, and it does not have the problem of immature convergence. The results of two cases show that using NOEGA to solve the optimal allocation model is very efficient and robust. In addition, the algorithm complexity of NOEGA is discussed.

关键词： water resources optimal allocation node ordinal code genetic algorithm.

Response to“Discussion on the systematic position of the Early Cambrian priapulomorph worms”

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Science Bulletin 2006年第2期51卷 250-256页

作者： HAN Jian1 & HU Shixue2.1. Department of Geology and key laboratory for Continental Dynam- ics of the {2. ministry, Northwest university, Xi’an 710069, china 2. Yunnan Geological Institute, Kunming 650011, china Department of Geology and key laboratory for Continental Dynamics of the {2. ministry Northwest University Xi’an China Yunnan Geological Institute Kunming China

A response by Han Jian & Hu Shixue to a letter to the editor about their article 'Systematic Position of the Early Cambrian priapulomorph worms' in the 2.04 issue is presented.

关键词： Response to Discussion on the systematic position of the Early Cambrian priapulomorph worms

A new relative radiometric consistency processing method for change detection based on wavelet transform and a low-pass filter

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Science china(Technological Sciences) 2010年第S1期53卷 7-14页

作者： SUN KaiMin1,SUI HaiGang1,2.LI DeRen1 & XU Chuan1,2.1 State key laboratory of Information Engineering in Surveying,Mapping and Remote Sensing,{2. university,{2. 430079,china 2.State key laboratory of Subtropical Building Science,South china university of Technology,Guangzhou 510640,china State key laboratory of Information Engineering in Surveying Mapping and Remote Sensing Wuhan University Wuhan China State key laboratory of Subtropical Building Science South China University of Technology Guangzhou China

The research purpose of this paper is to show the limitations of the existing radiometric normalization approaches and their disadvantages in change detection of artificial objects by comparing the existing approaches,on the basis of which a preprocessing approach to radiometric consistency,based on wavelet transform and a spatial low-pass filter,has been *** approach first separates the high frequency information and low frequency information by wavelet ***,the processing of relative radiometric consistency based on a low-pass filter is conducted on the low frequency *** processing,an inverse wavelet transform is conducted to obtain the results *** experimental results show that this approach can substantially reduce the influence on change detection of linear or nonlinear radiometric differences in multi-temporal images.

关键词： wavelet transform radiometric normalization low-pass filter change detection

Experimental Examination of Velocity-Models in Estimating Gas Hydrate Saturation in Sediments

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地学前缘 2009年第S1期16卷 224-225页

作者： Gaowei Hu~(1,3),Yuguang Ye~(2.3),Jian Zhang~(2.3),Jiasheng Wang~1 1.Faculty of Earth Sciences,china university of geosciences(wuhan),{2.,china. 2.key laboratory of Marine Hydrocarbon resources and Environment resources,the ministry of Land and resources,Qingdao 2.6071,china 3.Qingdao Institute of Marine Geology,the ministry of Land and resources,Qingdao 2.6071,china

Elastic velocities(v_p and v_s)have been widely used in estimating gas hydrate saturation in void spaces of *** commonly used models are empirical equations or some physically based models,such as Wyllie’s time average,Effective Medium Theory (EMT),Modified Biot-Gassmann Theory by Lee (BGTL),*** equations or models are selective to distinct *** order to evaluate the app-

关键词： gas hydrates saturation elastic velocities models applicability

Design theory and method of multivariate hash function

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Science china(Information Sciences) 2010年第10期53卷 1977-1987页

作者： WANG HouZhen 1,2., ZHANG HuanGuo 1 , WU QianHong 1 , ZHANG Yu 1 , LI ChunLei 1 & ZHANG XinYu 1 1 The key laboratory of Aerospace Information Security and Trusted Computing, {2. of education, School of Computer, wuhan university, wuhan 430072. china 2.key laboratory of Mathematics Mechanization, Beijing 100080, china The key laboratory of Aerospace Information Security and Trusted Computing Ministry of Education School of Computer Wuhan University Wuhan China key laboratory of Mathematics Mechanization Beijing China

This paper proposes a novel hash algorithm whose security is based on the multivariate nonlinear polynomial equations of NP-hard problem over a finite field and combines with HAIFA iterative framework. Over the current widely used hash algorithms, the new algorithm has the following advantages: its security is based on a recognized difficult mathematical problem; the hash length can be changed freely; its design can be automated such that users may construct specific hash function meeting the actual needs. Furthermore, we discuss the security, efficiency and performance of the new algorithm. Under some related difficult mathematical assumptions and theoretical analysis, the new algorithm is proven practical by the experiment results, and capable of achieving security of an ideal hash function by choosing suitable parameters. In addition, it can also be used as a pseudo-random number generator for the good randomness of its output.

关键词： cryptology hash function MQ problem multivariate polynomials

Stress distribution rule of roadway affected by overhead mining in gently inclined coal seams group

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中国有色金属学会会刊：英文版 2011年第S3期21卷 529-535页

作者： KANG Qin-rong1, 2. TANG Jian-xin1, 2. HU Hai1, 2. ZHANG Wei-zhong1, 3 1. College of Resource and Environmental Sciences, Chongqing university, Chongqing 400030, china 2. State {2. laboratory of Coal Mine Disaster Dynamics and Control, Chongqing university, Chongqing 400030, china 3. School of Safety Science and Administration, Zhongnan university of Economics and Law, wuhan 430074, china College of Resource and Environmental Sciences Chongqing University Chongqing 400030 China State key laboratory of Coal Mine Disaster Dynamics and Control Chongqing University Chongqing 400030 China School of Safety Science and Administration Zhongnan University of Economics and Law Wuhan 430074 China

In light of the severe deformation and destruction of the district raise tunnel in the mining area at the northern part of the Lubanshan colliery, by the theoretic analysis and numerical simulation, both the mining stress distribution in seams group and the deformation and destruction mechanism of floor district raise were investigated. The results show that, at the maximum vertical distance of 40 m, the abutment stress has an influence on the recovery of 2. and 3# coal seam and 8# coal seam at distance of 30 m. As a result, the recovery of 8# is rather than those of 2. or 3# coal seam, which contributes to the deformation and destruction of the district raise surrounding rock. The major factors affecting the abutment stress include the mining depth, mining height, residual gob space, adjacent working faces and short spacing coal seam recovery.

关键词： coal seams group stress distribution district raise surrounding rock deformation and destruction abutment stress

Simulation of Tensile Behavior of Nickel Foam

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稀有金属材料与工程 2011年第S3期40卷 224-227页

作者： Zhao Mingjuan 1, Zhang Xiaolan 1, Zhao Longzhi 1,3, Zhang Jinsong 2.1 key laboratory of {2. of education for Conveyance and Equipment, East china Jiaotong university, Nanchang 330013, china 2.Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, china 3 key laboratory of Superlight Materials & Surface Technology, {2. of education, Harbin Engineering university, Harbin 150001, china E china Jiaotong Univ Key Lab Minist Educ Conveyance & Equipment Nanchang 330013 Peoples R China Harbin Engn Univ Minist Educ Key Lab Supertight Mat & Surface Technol Harbin 150001 Peoples R China Chinese Acad Sci Inst Met Res Shenyang 110016 Peoples R China

Nickel foam is widely used as the electrode, the catalyst carrier, sound absorption material and other application fields. The tensile behavior of the open cell nickel foam which is one of the most important parameters in the design process was investigated with the finite element method based on ANSYS software in this paper. The effects of strain rates and temperature on the yield strength of the nickel foam were obtained. The results show that the yield strength exhibit a nonlinear reduction with the increases of the temperature for the elastic bending of the struts of the reinforcement grew quickly depending on the temperature. However, the yield strength increases slowly with the improvement of the strain rate because the strain rate neither change the internal structure and properties such as the porosity and the aperture, nor alter the external circumstance in order to change the internal properties such as the temperature. The results of the simulation accord with those of the experiments, which is very important to understand the tensile behavior of the foam materials.

关键词： nickel foam ANSYS yield strength temperature strain rate