检索结果-南通市图书馆

中国科学：技术科学英文版 2011年第S1期54卷 185-191页

作者： LIU HaoWu 1,2,CHEN Jiang 2,SUN Man 3 & DING Rui 2 1 State Key Laboratory of Hydraulics and Mountain River engineering,sichuan university,chengdu 610065,china 2 school of Water Resource Hydropower,sichuan university,chengdu 610065,china 3 school electrical engineering and information,sichuan university,chengdu 610065,china sichuan Univ State Key Lab Hydraul & Mt River Engn Chengdu 610065 Peoples R China sichuan Univ Sch Water Resource Hydropower Chengdu 610065 Peoples R China sichuan Univ Sch Elect Engn & Informat Chengdu 610065 Peoples R China

The micromechanical behaviors and mechanics-optics coupling effects of optic-fiber-concrete complex in the distributed optic-fiber sensing concrete-crack technology,which was used in health monitoring of Wu Gorge Bridge on Yangtze River and a large dam successfully,have been investigated.A micromechanical theoretical analysis method and micromechanical frictional contact bi-interface model,as well as a modified optical theoretical analysis method of the mechanics-optics coupling effects are presented.A series of verification experiments,including mechanical experiments and mechanics-optics coupling experiments,have been *** results of micromechanical theoretical analysis and the analysis of the modified theory of mechanics-optics coupling along with mechanical and optical experimental data are shown to be in close *** the micromechanical theory and the modified theory of mechanics-optics coupling with their analysis methods can not only enhance credibility of this novel distributed sensing technology but also provide a way to understand its sensing mechanism and optimize its technical details and system.

关键词： optic-fiber sensing mechanics-optics coupling micromechanics health monitoring concrete structure crack detection

A novel evolving model for power grids

在线全文

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2010年第10期53卷 2862-2866页

作者： LIU Xuan, LIU TianQi & LI XingYuan school of electrical engineering and Automation, sichuan university, chengdu 610065, china 1. school of electrical engineering and Automation Sichuan University Chengdu 610065 China

In this paper,a novel power grid evolving model,which can well describe the evolving property of power grids,is presented. Based on the BA model,motivated by the fact that in real power grids,connectivity of node not only depends on its degree,but also is influenced by many uncertain factors,so we introduce the subconnection factor K for each node. Using the mean-field theory,we get the analytical expression of power-law degree distribution with the exponent γ∈ (3,∞ ). Finally,simulation results show that the new model can provide a satisfactory description for empirical characteristics of power network,and power network falls somewhere in between scale-free network and uncertain network.

关键词： power grid evolving model scale-free

A new real-time eye tracking based on nonlinear unscented Kalman filter for monitoring driver fatigue

在线全文

学校读者我要写书评

暂无评论

控制理论与应用（英文版） 2010年第2期8卷 181-188页

作者： Zutao ZHANG 1 , 2 , Jiashu ZHANG 2 (1.school of Mechanical engineering, Southwest Jiaotong university, chengdu sichuan 610031, china 2.sichuan Key Lab of Signal and information Processing, Southwest Jiaotong university, chengdu sichuan 610031, china) school of Mechanical engineering Southwest Jiaotong University Chengdu Sichuan China sichuan Key Lab of Signal and information Processing Southwest Jiaotong University Chengdu Sichuan China

A new scheme for driver fatigue detection is presented, which is based on the nonlinear unscented Kalman filter and eye tracking. Assuming a probability distribution than to approximate an arbitrary nonlinear function or transformation, eye nonlinear tracking can be achieved using an unscented transformation (UT), which adopts a set of deterministic sigma points to match the posterior probability density function of the eye movement. Driver fatigue can be detected using the percentage of eye closure (PERCLOS) framework in a realistic driving condition after the eye nonlinear tracking. This system was tested adequately in realistic driving environments with subjects of different genders, with/without glasses, in day/night driving, being commercial/noncommercial drivers, in continuous driving time, and under different road conditions. The last experimental results show that the proposed method not only improves the robustness for nonlinear eye tracking, but also can provide more accurate estimation than the traditional Kalman filter.

关键词： Eye tracking Unscented Kalman filter (UKF) Fatigue detection PERCLOS

Surrogate model-assisted interactive genetic algorithms with individual’s fuzzy and stochastic fitness

在线全文

学校读者我要写书评

暂无评论

控制理论与应用（英文版） 2010年第2期8卷 189-199页

作者： Xiaoyan SUN, Dunwei GONG (school of information and electrical engineering, china university of Mining and Technology, Xuzhou Jiangsu 221116, china) school of information and electrical engineering China University of Mining and Technology Xuzhou Jiangsu China

We propose a surrogate model-assisted algorithm by using a directed fuzzy graph to extract a user’s cognition on evaluated individuals in order to alleviate user fatigue in interactive genetic algorithms with an individual’s fuzzy and stochastic fitness. We firstly present an approach to construct a directed fuzzy graph of an evolutionary population according to individuals’ dominance relations, cut-set levels and interval dominance probabilities, and then calculate an individual’s crisp fitness based on the out-degree and in-degree of the fuzzy graph. The approach to obtain training data is achieved using the fuzzy entropy of the evolutionary system to guarantee the credibilities of the samples which are used to train the surrogate model. We adopt a support vector regression machine as the surrogate model and train it using the sampled individuals and their crisp fitness. Then the surrogate model is optimized using the traditional genetic algorithm for some generations, and some good individuals are submitted to the user for the subsequent evolutions so as to guide and accelerate the evolution. Finally, we quantitatively analyze the performance of the presented algorithm in alleviating user fatigue and increasing more opportunities to find the satisfactory individuals, and also apply our algorithm to a fashion evolutionary design system to demonstrate its efficiency.

关键词： Interactive genetic algorithms User fatigue Surrogate model Directed fuzzy graph Fuzzy entropy

Adaptive interactive genetic algorithms with individual interval fitness

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2008年第3期18卷 359-365页

作者： Dunwei Gong , Guangsong Guo, Li Lu, Hongmei Ma school of information and electrical engineering, china university of Mining & Technology, Xuzhou 221008, china school of information and electrical engineering China University of Mining & Technology Xuzhou 221008 China

It is necessary to enhance the performance of interactive genetic algorithms in order to apply them to complicated optimization prob- lems successfully. An adaptive interactive genetic algorithm with individual interval fitness is proposed in this paper in which an indi- vidual fitness is expressed by an interval. Through analyzing the fitness, information reflecting the distribution of an evolutionary population is picked up, namely, the difference of evaluating superior individuals and the difference of evaluating a population. Based on these, the adaptive probabilities of crossover and mutation operators of an individual are presented. The algorithm proposed in this paper is applied to a fashion evolutionary design system, and the results show that it can find many satisfactory solutions per generation. The achievement of the paper provides a new approach to enhance the performance of interactive genetic algorithms.

关键词： Optimization Genetic algorithm Interaction Interval Probability of genetic operator

Design,analysis and control of hybrid excited doubly salient stator-permanent-magnet motor

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2010年第1期53卷 188-199页

作者： ZHU XiaoYong1,2 & CHENG Ming1 1 engineering Research Center for Motion Control of MOE,school of electrical engineering,Southeast university,Nanjing 210096,china 2 school of electrical and information engineering,Jiangsu university,Zhenjiang 212013,china 1. engineering Research Center for Motion Control of MOE School of Electrical Engineering Southeast University Nanjing 210096 China2. School of Electrical and Information Engineering Jiangsu University Zhenjiang 212013 China

In this paper,a new hybrid excited doubly salient stator-permanent-magnet motor is proposed,where both permanent magnets and DC field windings are located in the *** theory,the mathematical model and design method of the motor are *** corresponding output power equation and the relationship between the flux control capability and the extended speed range are deduced in *** using an efficient "one-step" three-dimensional(3D) finite element method,the electromagnetic performances are analyzed,in which the leakage flux outside the stator circumference and end-effect are taken into *** on the operation principle of the motor,the control strategy and scheme are developed and implemented *** experimental results and finite element analysis show that the proposed motor not only maintains the advantages of doubly salient permanent magnet motors,but also offers high energy efficiency over a wide speed range,which makes the motor an interesting candidate for electric vehicles.

关键词： stator permanent magnet motor hybrid excitation doubly salient finite element method flux weakening control

Frequency/time hopping sequence sets with optimal partial Hamming correlation properties

在线全文

学校读者我要写书评

暂无评论

Science china(information Sciences) 2012年第10期55卷 2207-2215页

作者： NIU XianHua 1,2,PENG DaiYuan 1 & ZHOU ZhengChun 3 1 The Provincial Key Laboratory of information Coding and Transmission,Institute of Mobile Communications,Southwest Jiaotong university,chengdu 610031,china 2 The school of Mathematics and Computer engineering,Xihua university,chengdu 610039,china 3 The College of Maths,Southwest Jiaotong university,chengdu 610031,china 1. The Provincial Key Laboratory of information Coding and Transmission Institute of Mobile Communications Southwest Jiaotong University Chengdu 610031 China 2. The school of Mathematics and Computer engineering Xihua University Chengdu 610039 China 3. The College of Maths Southwest Jiaotong University Chengdu 610031 China

Frequency hopping/time hopping(FH/TH) sequences have found wide applications in various modern FH/TH spread spectrum communications,such as digital cellular mobile communication,short-range wireless communication,personal communication,and multi-user radar,sonar *** order to evaluate the goodness of FH/TH sequences design,the periodic Hamming correlation function is used as an important ***,the length of correlation window is shorter than the period of the chosen FH/TH sequence,so the study of the partial Hamming correlation of FH/TH sequence is particularly *** this paper,a new class of FH/TH sequence sets with good partial Hamming correlation properties is proposed and *** construction of new FH/TH sequence sets is based upon the generalized m-sequence and generalized Gordon-Mills-Welch sequence over a polynomial residue class *** is shown that new FH/TH sequence sets are optimal with respect to the partial Hamming correlation bound.

关键词： frequency hopping/time hopping(FH/TH) sequence partial Hamming correlation optimal FH/TH sequence set

Dynamic scheduling model of computing resource based on MAS cooperation mechanism

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science in china(Series F) 2009年第8期52卷 1302-1320页

作者： JIANG WeiJin1,2, ZHANG LianMei3 & WANG Pu4 1 school of Computer and Electronic engineering, Hunan university of Commerce, Changsha 410205, china 2 school of information engineering, Xiangtan university, Xiangtan 411000, china 3 electrical engineering College, Wuhan university, Wuhan 430072, china 4 school of Commerce, Central South university, Changsha 410083, china 1. school of Computer and Electronic engineering Hunan University of Commerce Changsha 410205 China 2. school of information engineering Xiangtan University Xiangtan 411000 China 3. electrical engineering College Wuhan University Wuhan 430072 China 4. school of Commerce Central South University Changsha 410083 China

Allocation of grid resources aims at improving resource utility and grid application performance. Currently, the algorithms proposed for this purpose do not fit well the autonomic, dynamic, distributive and heterogeneous features of the grid environment. According to MAS （multi-agent system） cooperation mechanism and market bidding game rules, a model of allocating allocation of grid resources based on market economy is introduced to reveal the relationship between supply and demand. This model can make good use of the studying and negotiating ability of consumers＇ agent and takes full consideration of the consumer＇s behavior, thus rendering the application and allocation of resource of the consumers rational and valid. In the meantime, the utility function of consumer is given; the existence and the uniqueness of Nash equilibrium point in the resource allocation game and the Nash equilibrium solution are discussed. A dynamic game algorithm of allocating grid resources is designed. Experimental results demonstrate that this algorithm diminishes effectively the unnecessary latency, improves significantly the smoothness of response time, the ratio of throughput and resource utility, thus rendering the supply and demand of the whole grid resource reasonable and the overall grid load balanceable.

关键词： multi-agent system (MAS) resource scheduling model evolutionary game cooperation mechanism utility function

Improving anti-sulfur performance of methane sensors by new vectors and active components

在线全文

学校读者我要写书评

暂无评论

Mining Science and Technology 2010年第6期20卷 913-916页

作者： WANG Ying, TONG Minming, ZHANG Tao school of information and electrical engineering, china university of Mining & Technology, Xuzhou 221008, china [a] school of information electrical engineering China University of Mining & Technology Xuzhou 221008 China

Conventional Pd/γ-A12O3 methane sensors are easily poisoned in a sulfur-containing atmosphere, with a subsequent decrease in sensitivity and the working life of methane sensors. We mainly investigated the effect of nanotechnology and a cerium co-catalyst on the stability and anti-sulfur performance of methane sensors. In our experiment, an anti-sulfur methane sensor was prepared by immersing cerium-containing γ-alumina nanometer elements into a Pt-Pd bimetallic nanometer catalyst. The experi- ment about the sensitivity and stability performance of different catalytic methane sensors indicate that sensitivity, decreased by catalyst sulfur poisoning, is improved significantly by adding cerium to the vector. As well, the long-term operational stability of methane sensors increased significantly.

关键词： Cerium anti-sulfur stability sensitivity

Numerical calculation on temperature field of FGH95 alloy droplet during rapid solidification

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 2003年第3期10卷 51-54页

作者： Huanming Chen and Benfu Hu Materials Science and engineering school, university of Science and Technology Beijing, Beijing 100083,china Physics and electrical information engineering school, Ningxia university, Yinchuan 750021,china Univ Sci & Technol Beijing Sch Mat Sci & Engn Beijing 100083 Peoples R China Ningxia Univ Phys & Elect Informat Engn Sch Yinchuan 750021 Peoples R China

The temperature field of FGH95 alloy droplet atomized by plasma rotatingelectrode processing (PREP) during solidification has been calculated through numerical analysisbased on equivalent sensible heat capacity method. And thus the relational curves among temperaturegradient of solid-liquid interface, moving velocity of solid-liquid interface and solid fractionduring solidification have been presented. The results indicate that the relation between averagetemperature gradient of solid-liquid interface and droplet size, and the relation between averagemoving velocity of solid-liquid interface and droplet size can be expressed during solidification.

关键词： FGH95 alloy droplet temperature field numerical calculation