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Robustness and breakup of the spiral wave in a two-dimensional lattice network of neurons

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Science china(Physics,Mechanics & Astronomy) 2010年第4期53卷 672-679页

作者： MA Jun 1,2. TANG Jun 2., ZHANG AiHua 3.& JIA Ya 2.1 Department of Physics, Lanzhou University of {3., Lanzhou 73.050,{2. 2.Department of Physics, Central{2. Normal University, Wuhan 43.079,{2. 3.college of electrical and information engineering, Lanzhou University of {3., Lanzhou 73.050,{2. 1. Department of Physics Lanzhou University of Technology Lanzhou 730050 China2. Department of Physics Central China Normal University Wuhan 430079 China3. College of Electrical and Information Engineering Lanzhou University of Technology Lanzhou 730050 China

The robustness and breakup of spiral wave in a two-dimensional lattice networks of neurons are investigated. The effect of small- world type connection is often simplified with local regular connection and the long-range connection with certain probability. The network effect on the development of spiral wave can be better described by local regular connection and changeable long-range connection probability than fixed long-range connection probability because the long-range probability could be changeable in realistic biological system. The effect from the changeable probability for long-range connection is simplified by multiplicative noise. At first, a stable rotating spiral wave is developed by using appropriate initial values, parameters and no-flux boundary conditions, and then the effect of networks is investigated. Extensive numerical studies show that spiral wave keeps its alive and robust when the intensity of multiplicative noise is below a certain threshold, otherwise, the breakup of spiral wave occurs. A statistical factor of synchronization in two-dimensional array is defined to study the phase transition of spiral wave by checking the membrane potentials of all neurons corresponding to the critical parameters(the intensity of noise or forcing current)in the curve for factor of synchronization. The Hindmarsh-Rose model is investigated, the Hodgkin-Huxley neuron model in the presence of the channel noise is also studied to check the model independence of our conclusions. And it is found that breakup of spiral wave is easier to be induced by the multiplicative noise in presence of channel noise.

关键词： spiral wave factor of synchronization breakup multiplicative noise robustness

Formal Verification under Unknown Constraints

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Wuhan University Journal of Natural Sciences 2005年第1期10卷 43-46页

作者： LI Guang-hui 1,2.3., LI Xiao-wei 2.3.. School of information {3., Zhejiang Forestry {2., Hangzhou 3.13.0, Zhejiang, china 2. Institute of Computing technology, Chinese Academy of Sciences, Beijing 100080, china 3. Graduate School of the Chinese Academy of Sciences, Beijing 10003., china School of information engineering Zhejiang Forestry College Hangzhou 311300 Zhejiang China

We present a formal method of verifying designs with unknown constraints (e.g., black boxes) using Boolean satisfiability (SAT). This method is based on a new encoding scheme of unknown constraints, and solves the corresponding conjunctive normal form (CNF) ***,this method can avoid the potential memory explosion, which the binary decision diagram (BDD) based techniques maybe suffer from, thus it has the capacity of verifying large designs. Experimental results demonstrate the efficiency and feasibility of the proposed method.

关键词： formal verification unknown constraints black box Boolean satisfiability Boolean comparison

Parameter identification theory of a complex model based on global optimization method

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Science china(Physics,Mechanics & Astronomy) 2008年第11期51卷 1722-1732页

作者： QU Jie1, JIN QuanLin2.& XU BingYe3.1 college of Automotive engineering, South{2. University of technology, Guangzhou 510640,{2. 2.Beijing Research Institute of Mechanical and electrical technology, Beijing 100083.{2. 3.Department of engineering Mechanics, Tsinghua University, Beijing 100084,{2. 1. college of Automotive engineering South China University of Technology Guangzhou 510640 China 2. Beijing Research Institute of Mechanical and electrical technology Beijing 100083 China 3. Department of engineering Mechanics Tsinghua University Beijing 100084 China

With the development of computer technology and numerical simulation technology, computer aided {2. (CAE) technology has been widely applied to many fields. One of the main obstacles, which hinder the further application of CAE technology, is how to successfully identify the parameters of the selected model. An elementary framework for parameter identification of a complex model is provided in this paper. The framework includes the construction of objective function, the design of the optimization method and the evaluation of the identified results, etc. The parameter identification process is described in this framework, taking the parameter identification of the superplastic constitutive model considering grain growth for Ti-6Al-4V at 92.°C as an example. The objective function is the weighted quadratic sums of the difference between the experimental and computational data for the stress-strain relationship and the grain growth relationship; the designed optimization method is a hybrid global optimization method, which is based on the feature of the objective function and incorporates the strengths of genetic algorithm (GA), the Levenberg-Marquardt algorithm and the augmented Gauss-Newton algorithm. The reliability evaluation of parameter identification result is made through the comparison between the calculated and experimental results and between the theoretical values of the parameters and the identified ones.

关键词： constitutive model parameter identification theory inverse analysis global optimization

Relations between thickness of UHMWPE’s wear debris and positive pressure of tribological system

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Chinese Science Bulletin 2008年第9期53卷 1435-1443页

作者： LIU HongTao1,2.3.& GE ShiRong1,3.1 Institute of Tribology and Reliability engineering, china University of Mining & {2., Xuzhou 2.1116, china 2.college of Mechanical and electrical engineering, china University of Mining & {2., Xuzhou 2.1116, china 3.Biotribology Center, State Key Laboratory of Tribology, Xuzhou 2.1116, china Institute of Tribology and Reliability engineering China University of Mining & Technology Xuzhou 221116 China college of Mechanical and electrical {2. China University of Mining & Technology Xuzhou 221116 China Biotribology Center State Key Laboratory of Tribology Xuzhou 221116 China

MiaoXAM2.5X-50X Ultrahigh Precision Surface 3. Profiler is introduced to research the relations be- tween thickness of UHMWPE’s wear debris and positive pressure of tribological system. Research re- sults show that thickness of wear debris owns evident classification, and the first grade thickness math model and the second grade thickness math model are built. By the second grade thickness math model, the true force condition in the tribological system can be gotten, and the model can be used as a tool to modify simulating parameters of the tribological system, and it is an important inspecting method to the airtight system which cannot be examined in real time. The first grade thickness math model can describe the true working load and surface condition of work piece in the tribological sys- tem, and is an effective description method for the running condition of frictional pairs. The research results at different lubricating conditions testify the relations between thicknesses of wear debris and positive pressure of the tribological system. The fractal relation between maximal thickness of wear debris and positive pressure is discussed. The conceptions of the immutability principle and charac- teristic granularity of wear debris thickness are brought forward and discussed. In conclusion, as a stable tribological parameter owning mechanical theory basis, wear debris thickness will play an im- portant part in fault diagnosis, especially for the airtight system such as artificial joint.

关键词：摩擦学磨损面厚度分形数学模型

Mining and Integrating Reliable Decision Rules for Imbalanced Cancer Gene Expression Data Sets

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Tsinghua Science and technology 2012年第6期17卷 666-673页

作者： Hualong Yu 1 , Jun Ni 2., Yuanyuan Dan 3., Sen Xu 4 1. School of Computer Science and engineering, Jiangsu University of Science and technology, Zhenjiang 2.2.03.{2. 2. Department of Radiology, Carver college of Medicine, The University of Iowa, Iowa City, IA 52.42. USA 3. School of Biology and Chemical engineering, Jiangsu University of Science and technology, Zhenjiang 2.2.03.{2. 4. School of information engineering, Yancheng Institute of technology, Yancheng 2.4051,{2. School of Computer Science and engineering Jiangsu University of Science and Technology Zhenjiang 212003 China|c|

There have been many skewed cancer gene expression datasets in the post-genomic era. Extraction of differential expression genes or construction of decision rules using these skewed datasets by traditional algorithms will seriously underestimate the performance of the minority class, leading to inaccurate diagnosis in clinical trails. This paper presents a skewed gene selection algorithm that introduces a weighted metric into the gene selection procedure. The extracted genes are paired as decision rules to distinguish both classes, with these decision rules then integrated into an ensemble learning framework by majority voting to recognize test examples; thus avoiding tedious data normalization and classifier construction. The mining and integrating of a few reliable decision rules gave higher or at least comparable classification performance than many traditional class imbalance learning algorithms on four benchmark imbalanced cancer gene expression datasets.

关键词： cancer gene expression data class imbalance paired differential expression genes decision ruleensemble learning majority voting

Finite Element Analysis of Die Geometry and Process Conditions Effects on Equal Channel Angular Extrusion for β-Titanium Alloy

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Journal of Iron and Steel Research International 2012年第10期19卷 54-58页

作者： SI Jia-yong1,2. GAO Fan3. ZHANG Ji3.(1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083. Hunan, china 2. {3. of Mechanical and {2. engineering, Central South University of Forestry and technology, Changsha 410004, Hunan, china 3. High Temperature Material Research Division, Central Iron and Steel Research Institute, Beijing 100081, china) [a] State Key Laboratory of Powder Metallurgy Central South University Changsha 410083 Hunan China [b] college of Mechanical and electrical {2. Central South University of Forestry and Technology Changsha 410004 Hunan China [c] High Temperature Material Research Division Central Iron and Steel Research Institute Beijing 100081 China

The finite element analysis was applied to evaluate the respective influences of die geometry and process conditions on plastic strain distribution for β-titanium (Ti-13.11Cr3.l) alloy during the equal channel angular extrusion (ECAE). It was found that optimum equal channel angular extrusion die geometry is strongly material dependent. Optimal strain homogeneity in the Ti-13.11Cr3.l alloy may be achieved at r (inner radius)=5 mm, R (outer radius)=3.mm. The equivalent plastic strain increases with increasing friction coefficient. And the better homogeneity of the equivalent plastic strain distribution can be achieved when friction coefficient value is lower. The faster the ram speed is, the lower the homogeneity of the equivalent plastic strain distribution is and the influence is slight. The back-pressure does not help to improve the plastic strain homogeneity, and the increasing temperature has a slightly favourable effect on the plastic strain homogeneity between 400 and 600 ℃.

关键词： equal channel angular extrusion finite element analysis die geometry β-titanium

Quantum secret sharing between m-party and n-party with six states

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Science china(Physics,Mechanics & Astronomy) 2009年第8期52卷 1191-1202页

作者： GAO Ting1,YAN FengLi2.3.& LI YouCheng2.3.1 college of Mathematics and {3. Science,Hebei Normal University,Shijiazhuang 050016,{2. 2.college of Physics and {3. engineering,Hebei Normal University,Shijiazhuang 050016,{2. 3.Hebei Advanced Thin Films Laboratory,Shijiazhuang 050016,{2. college of Mathematics and information Science Hebei Normal University Shijiazhuang 050016 China college of Physics and information {2. Hebei Normal University Shijiazhuang 050016 China Hebei Advanced Thin Films Laboratory Shijiazhuang 050016 China

A quantum secret sharing scheme between an m-party group and an n-party group is proposed using three conjugate bases.A sequence of single photons,each of which is prepared in one of the six states,is used directly to encode classical information in the quantum secret sharing *** this scheme,each of all m members in group 1 chooses randomly his/her own secret key individually and independently,and directly encodes his/her respective secret information on the states of single photons via unitary operations,then the last one sends 1/n of the resulting qubits to each member of group *** measuring their respective qubits,all members in group 2.share the secret information shared by all members in group *** renders impossible a Trojan horse attack with a multi-photon signal,a fake-signal attack with EPR pairs,an attack with single photons,and an attack with invisible *** give the upper bounds on the average success probabilities for dishonest agent eavesdropping encryption using the fake-signal attack with any two-particle entangled states.

关键词： quantum secret sharing security EPR pairs

Spatiotemporal model of open-pit based on 3.D deposit model

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中国有色金属学会会刊：英文版 2011年第S3期21卷 616-620页

作者： XIA Chun-lin1, ZHOU Hui1, LI Qing-yuan2. MA Zhen-li3.1. School of Geomatics, Liaoning Technical University, Fuxin 12.000, china 2. State Key Laboratory for GIS engineering, Chinese Academy of Surveying and Mapping, Beijing 10083., china 3. Yinchuan college, china University of Mining and technology, Yinchuan 750011, china [a] School of Geomatics Liaoning Technical University Fuxin 123000 China [b] State Key Laboratory for GIS engineering Chinese Academy of Surveying and Mapping Beijing 100830 China [c] Yinchuan college China University of Mining and Technology Yinchuan 750011 China

A new method was put forward to make up the three-dimensional deposit model, and the spatiotemporal models of open-pit with temporal dynamics were also studied combined with the corrected models of multilevel ground states so as to bring the three-dimensional open-pit model at different time and its model serial formed from the evolvement into the management of temporal dimension in order to realize the spatial three-dimension and temporal dynamic for the mining management in open-pits,which makes this model easy to query and analyze 3.D information, also help surface mining replaying and stope evolution forecasting. Finally, the time-spatial model was established to show the dynamic mining on some open-pit under the windows XP and VC++ environment.

关键词： 3. model of deposit three-dimensional model mixed model temporal model open-pit

Vision navigation algorithm for mine agent based on quaternion

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中国有色金属学会会刊：英文版 2011年第S3期21卷 610-615页

作者： LI Ke-zhao1, 4, LEI Wei-wei1, 2. GUO Zeng-zhang1, 2. WU Li-xin3. ZHANG Qin4 1. School of Survey and Land information {3., Henan Polytechnic University, Jiaozuo 454003.{2. 2. Key Laboratory of Mine Spatial information Technologies of State Bureau of Surveying and Mapping, Henan Polytechnic University, Jiaozuo 454003.{2. 3. college of Resources and Civil {3., Northeastern University, Shenyang 110819,{2. 4. college of Geology {3. and Geomatics, Chang’an University, Xi’an 710054,{2. [a] School of Survey and Land information engineering Henan Polytechnic University Jiaozuo 454003 China [b] Key Laboratory of Mine Spatial information Technologies of State Bureau of Surveying and Mapping Henan Polytechnic University Jiaozuo 454003 China [c] college of Resources and Civil engineering Northeastern University Shenyang 110819 China [d] college of Geology engineering and Geomatics Chang'an University Xi'an 710054 China

Autonomous relative navigation is the key technology in mining or rescuing. On the basis of mine requirement and the theories of machine vision, an autonomous relative navigation algorithm for mine agent based on quaternion was proposed. In rotation transformation, this algorithm was represented by using quaternion. Because the Jacobi matrix of this method is lower than that of Hall algorithm, the calculation efficiency is improved by using this algorithm. The results of these experiments show that the computation burden of this algorithm based on quaternion is about half that of Hall algorithm. This algorithm based on quaternion is improved as a valid way to solve the problem of mine real-time navigation.

关键词： quaternion mine agent vision navigation