Table of Content

30 September 1999, Volume 17 Issue 3

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Articles

An Effective Method for Diffraction Characteristics of Dielectric Periodic Structures with Arbitrary Profiles

XU SHANJIA, YANG LI

1999, 17(3):  253-258. 

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Wave diffraction characteristics of dielectric periodic structures with arbitrary grating profiles for TE and TM polarizations are analyzed by a method which combines the multimode network theory with the rigorous mode matching procedure. The variations of the diffraction with the change of frequency and incident angle for the periodic structures with different grating profiles, such as sinusoid, triangle, trapezoid, increasing cosine and semiellipse are systematically studied. The effectiveness and accuracy of the present method are verified by the results given in the literature.

Chaotic Neural Network for Associative Memory

ZHANG YIFENG, YANG LÜXI, HE ZHENYA

1999, 17(3):  259-266. 

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Based on current research on applications of chaotic neurons network for information processing, a new auto-associative matrix is devised for artificial neural network composed of chaotic neurons. And then, a chaotic neurons network for associative memory is built up. From numerical simulation experiments, it has proved that its associative success rate and recall speed are improved by comparing with existing methods. Moveover, the associative recalling process of the network is theoretically analyzed in detail and explanations of improvement are given.

A New Method for Founding State Equations The Approach of Branch Substitutions and Extended Nodal Voltage Equations

LI FENG, XIANG CHANGSHUN, HE XIUFEN

1999, 17(3):  267-275. 

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In this paper, the node voltage analysis which is originally the most useful method for linear networks in the S-domain has been reformed into a new method for founding state equations. Comparing with original methods, the new method is not only simple and convenient, but also suitable for any linear and nonlinear circuits.

An Extraction Method of Crankshaft Dynamic Unbalance Signal

YU LIZHENG, GONG XIANGDONG, LIN SHICHOU, LIU YE, LU QIN

1999, 17(3):  276-281. 

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Principles of a typical circuit for extracting dynamic unbalance signals are analyzed, and a method used for the dynamic unbalance signal measurement is given. A newly developed dynamic balance machine based on the method has such features as high precision, high reliability, low cost and short time for research and development.

Neural Dynamics of Interval Bidirectional Associative Memory with Delays and Robust Interval Stability Analysis

LIAO XIAOFENG, LIU GUANGYUAN, WU ZHONGFU, YU JUEBANG

1999, 17(3):  282-288. 

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In this paper neural models of interval bidirectional associative memory with axonal signal transmission delays are given. By using stability theory of the interval dynamical systems and constructing suitable Lyapunov functionals, robust stability of those DIBAM are investigated and sufficient conditions are obtained respectively. Computer simulations are made by use of some examples. It demonstrates correctness for obtained conditions of robust stability.

Finite-Difference Time-Domain Treatment for Interfaces Penetrating Sound Waves

WANG TONG, WANG SHUOZHONG

1999, 17(3):  289-295. 

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Expressions for the treatment of interfaces penetrating sound waves, which is used in the finite-difference time-domain modeling of underwater acoustics, are derived. The proposed finite-difference boundary condition expands the scope of application of FDTD to scattering problems of objects with a finite acoustic impedance but without tangential stress. Numerical experiments have been carried out for several scattering problems, which give satisfactory field distributions. All the computation results are in good agreement with theoretical solutions.

Associative Memory of Gray-Scale Images with Chaotic Neural Networks

LI KE, YANG LÜXI, HE ZHENYA

1999, 17(3):  296-301. 

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In this paper, we propose a novel correlative learning rule for multi-value patterns, considering that conventional associative memory system processes only binary ones. Successful memory and recognition are achieved on the bases of S -GCM model with the proposed method, and analyses on the recognition results and factors are given.

Mixed Spectral Domain Approach Analysis of the Coupling Characteristics of Microshield Lines

LI JIPENG, GONG XUN, CAI SHUZHEN

1999, 17(3):  302-308. 

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The low crosstalk characteristics of microshield lines are investigated through mixed spectral domain approach. The formula and numerical results are presented. And the results are compared with those of microstrip lines. The analysis has revealed that microshield lines possess much lower coupling coefficients than traditional transmission lines. So microshield line structure is believed to be quite useful for realizing high density MMIC.

The Study on Fuzzy Self-Organizing Control Based on Neural Networks for Ship Maneuvering

CHENG QIMING, WAN DEJUN, CHEN XUELI, LI ZIGANG

1999, 17(3):  309-315. 

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According to nonlinear and time -varing parameters of ship maneuvering, the method of fuzzy neural networks which is used to fuzzy self -organizing control is proposed. The structure and knowledge representation of the method is described. The simulation results show that the performance of this method is good.

A New Method and a Device for Fast Evaluating Graphite Shape in Liquid Cast lron

LI DAYONG, KANG JIUZHOU, ZHANG YUTONG, TAO GUOGANG

1999, 17(3):  316-320. 

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In the paper, a new method and a device for fast evaluating the graphite shape in liquid cast iron are advanced. The new method is named amplitude and frequency equivalent of bubbles and its foundation is to take the pressure in the bubble and the frequency of blowing bubbles as the characteristics to obtain the equivalent by which the graphite shape in liquid cast iron can be known before casting. The testing process will take only 10 seconds. The new device based on the new method consists of a heat resistant and replaceable detector and a microcomputer acquisition system. The new method and the device have advantages of convenient operation, high resolution ratio and high anti-jamming ability.

The Solution of a Dual Integral Equation System with the Method of Gaussian Integration

LIU YI, MA GUICUN, MA YONGLI, DAI XIANXI

1999, 17(3):  321-326. 

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A dual integral equation system was decoupled and its dimensions were reduced by means of integral transformations and Schlömilch theorem in this paper. A formula for the integral kernel was found by "depressing oscillations in a narrow interval". Based on this formula, the high accurate solution of the integral equation was obtained by Gaussian integration method. And the correction function and curves were obtained with high-accuracy. It is emphasized that Gaussian integration will be very powerful in solving integral equation if one can get a suitable formula for calculating its non-elementary integral kernal.

Heat Transfer to Non -Newtonian Power-Law Fluid Freely-Falling Film Flow

JIANG ZHANGYAN, TAO ZHENGWEN, YAN WEIPING

1999, 17(3):  327-333. 

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The objective of the present paper is to study experimentally the heat transfer to non-Newtonian power-law fluid falling films flowing down the outside surface of a vertical stainless steel tube which has 20mm in outside diameter, 1mm in thickness, and 1100mm in length. The test liquid is an aqueous solution of carboxymethycellulose sodium(CMC solution) with the concentration of 8000×10^-6 (mass ratio). Rheological parameters of the solution were measured by the NXS -11 rotational viscosimeter within t=15~85℃ and empirical formulae for the variation of the parameters with solution temperatures are given as follows:n=0.644+0.245×10^-2 t, K=1.365exp(-0.0305 t), where n is the flow behavior index and K is the consistency coefficient. Based on a simplified physical model, the correlation of the average Nusselt number as a function of the modified Reynolds number and the modified Prandtl number can be obtained by fitting the test data. The correlation is given as follows:Nu_pl=2.0 Re_pl^0.395 Pr_pl^1/3.

The Oppenheim's Inequality for Fan Products of M-Matrices

YANG ZHONGPENG, LIU JICHUN

1999, 17(3):  334-336. 

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In this paper we give a generalization of the Oppenheim's inequality for Fan product of two M-matrices. Our result strengthens known those obtained by T.Ando, Huang Tinzhu respectively.

Natural Genetic Algorithm and Its Performance Analysis

LI GANG, TONG FU

1999, 17(3):  337-342. 

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There are three difficult problems in the application of genetic algorithm, namely the parameter control, the premature convergence and the deception problem. Based on genetic algorithm with varying population size, a self-adaptive genetic algorithm called natural genetic algorithm (nGA) is proposed. It introduces the population size threshold and the immigrant concepts, and adopts dynamically changing parameters in this paper. The design and structure of the nGA are discussed, and the performance of nGA is also analyzed.

A Global Security System Model with Multiple Security Classes for ODP Environment

QIN ZHIGUANG, LIU JINDE, SUN SHIXIN

1999, 17(3):  343-348. 

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A lattice model of the global security system is presented, and its expression and construction are discussed in this paper. Based on the lattice model, a global security system model with multiple security classes for ODP environment is derived, in which security domains are labeled as different security class, and the whole system are organized with multiple security classes and hierarchy.

The Effects of a Magnetic Field on the Eliminating Bubbles in the Fluidized Bed

GUI KETING, SHI MINGHENG

1999, 17(3):  349-354. 

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Through analysing the magnetic stress tensor which exerts on the surface of particles, the reason of eliminating bubbles in the fluidized bed with a magnetic field is explained. An experimental research of removing bubbles in the fluidized bed with a magnetic field is carried out and it is shown that the magnetic field can not only check the bubbles and widen the range of the velocity of the particulate fluidization, but also eliminate the bubbles and change the aggregative fluidization into the particulate one.

Several Technical Problems of Laser Application in Grinding Wheel Measurement

YANG YONGSHENG, LI HANZHONG

1999, 17(3):  355-360. 

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In this paper, grinding wheel wear is measured by laser power spectrum. By analyzing the real power spectrum of grinding wheel wear with "experiment and statistics method", the detecting princple of laser power spectrum is proved, and its half with ξ₀ is determined by the spectrum center to the position in which the intensity drops to 4% its maximum intensity. In addition, the grinding wheel parameters with the aluminum disk wheel are calibrated. Finally, the detecting experiments on the worn grains distribution are carried out, and grinding mechanism is identified.

The Effects of Response Modality (Foot or Hand) on Overlapped-Task in Man -Machine Operation Interaction

LI YONGJIAN

1999, 17(3):  361-365. 

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For the design of man-machine operation interaction in the complexity and speed man-machine system the results showed, that using different response modality (foot-hand) did not eliminate and reduce PRP interference, and could not raise the performance of overlapped -task. But lowering the complexity of selecting response could raise the performance of overlapped -task. The grade of complexity of selecting respose was in direct proportion to the degree of PRP (psychological refractory period) interfe rence.

Theoretical Approach to the Thermal Conductivity of Wood in the Radial Direction

YANG QINGXIAN

1999, 17(3):  366-370. 

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It is suggested that the phonon is the carrier of the transmission of thermal energy in wood in this paper. The theoretical expression of the thermal conductivity of wood in the radial direction is developed on the basic principles of the physical mecha nics. Then, the thermal conductivity of 18 species of trees can be calculated by the formula with the maximum relative error 13.7%, the average relative error 5.3%. Compared with the experimental value in the same condition, the calculation result is satisfactory.

The Mathematical Model of Design Parameter for the Smoke Preventing Air Curtain in the High-Rise Building

HE JIAPENG, WANG DONGFANG, WANG JIAN, JIANG ZHENGLIANG, YAN JIANPING

1999, 17(3):  371-376. 

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In this paper through analyzing smoke-flow field theoretically, it is discussed that the effect of air flow in a high-rise building is as a result of gas expansion by the temperature, the chimney effect, the outdoor wind power and a ventilation and air conditioning system when firing. The flow field at the staircase door is theoretically found. The way in which the diffusion of smoke is controlled is advanced according to the principle of flow line-rate of flow and based on the previous experimental researches by others, the mathematical mode of design parameter for the smoke preventing air curtain is inferred.

Analytic Solutions of a Reaction Diffusion System Arising in the Theory of Superconductivity

GU YUAN, GUO BENYU, GU YI

1999, 17(3):  377-378. 

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A reaction diffusion system arising in the theory of superconductivity is considered and its many kinds of analytic solutions are constructed by the Painlevé analysis and similarity reduction methods.