THE ELIMINATION OF UNDETERMINED MULTIPLIERS OF MOTION EQUATIONS OF NONHOLONOMIC SYSTEMS

This paper studies several kinds of motion equations of nonlinear nonholonomic constraint systems. On the basis of the motion equations of the first order nonholonomic system and the theory of the zero factor of matrix multiplying from the left, the general equations of the system without undetermined multipliers is derived. By applying the method to arbitrary order nonholonomic systems, the motion equations of the systems are gained.     

Accurate measurement for objects space attitude based on planar target

On the basis of studying the accurately identification algorithm of planar target and transformation model of the space vector, the imaging target models and spatial attitude measurement models are established. Then, a new topological positioning method is put forward. Finally, the four-wheel location measurement is given as an example. The results demonstrate that the method has better anti-interference and higher measurement precision, which provides a feasible method for a machine vision measurement system by using the plane target.     

A calculation method for coalbed permeability by using drainage data

In order to more accurately calculate the changes in the permeability of coalbed during production process, a calculation method for coalbed permeability based on production data is established by combining with material balance equations and production equations, and it gives the fact that the output data can be a good reflection of the inner permeability of coalbed. The average pressure of coalbed in production process can be calculated through material balance equation. Dimensionless water production index is introduced into the production equation in the stage only with water production. In the next stage with both gas and water, gas and water production ratio is introduced to eliminate the influence of flush-flow radius, skin factor as well as other uncertain factors on the calculation of CBM permeability. The relationship between permeability and surface cumulative liquid production can be described as a single-variable cubic equation by derivation. There is a trend that the permeability declines firstly and then increases after wells in Qinshui CBM field are calculated. The results show that reservoir permeability increase after drainage stage, but the growth rate decrease gradually. The regression result of the permeability ratio and surface cumulative fluid production agrees with the theoretical mathematic relationship.     

The edge element method in the forward problem of magnetic inductiontomography with homogeneous sinusoidal magnetic excitation

The edge finite element method and the imaging visualization have been studied in the forward problem of magnetic induction tomography MIT with homogeneous sinusoidal magnetic excitation. The definite equations of the forward problem were established using the electric field intensity as the vector variable. The edge FE method for solving the definite equations was introduced in detail and realized as the MATLAB program. In order to realize the visualization of MIT in imaging the intracranial hemorrhage, a real human brain finite element model was created with the human head MRI data. On the basis of this model, we realized the 3D visualization of MIT imaging in MATLAB. The research results demonstrated the validity of the definite equations and the edge FE method in calculating the forward problem. And the 3D visualization of MIT imaging with real human brain model established a foundation for the application study of MIT in imaging intracranial hemorrhage.     

Calculation Method of Hydraulic Characteristics for Direct-Return Chilled Water System

In order to optimize design and operation, it is necessary to calculate accurately hydraulic characteristics large central air-conditioning systems. Simplified Model can not be applied to hydraulic calculation of large pipe network topological structure for its large calculation error. Taking into account the regulating characteristics of terminal branch temperature regulating valve, a direct-return chilled water system is studied, an accurate mathematical model of pipe network hydraulic characteristics has been established and a computer logic algorithm with virtual flow has been given. A direct-return pipe network with ten AHU branches is used as simulation calculation object, the pipe network supply-return water pressure difference is calculated, and also the temperature regulating valve opening and actual flow of each branch are calculated in the condition of different supply-return water pressure difference. The calculated results accord with the natural characteristics of high pressure difference unbalanced for direct-return pipe network. The calculation method can ensure calculation convergence.     

STUDY OF SOLUTION METHODS FOR SEPARATOR EQUATIONS OF HIGH GRADIENT MAGNETIC SEPARATION

In this paper, an analytical solution,approximate solution of initial retention, steady-state solution and numerical solution of separator equations of high gradient magnetic separation are discussed. A backward-vave method used to improve the steady-state solution and Treanor-four order Taylor numerical method are suggested for magnetic separator equations and are compared with experimental results.     

黑龙江省农业企业内部绩效评价

随着农业产业化的推进,农业企业得到较快发展,为了实现农业企业的科学管理,要求对农业企业内部绩效进行评价。网络区间DEA方法是将农业企业分为若干个非完全独立的子系统,每个子系统中包括输入、输出和中间变量。笔者在大量理论研究的基础上,采用网络DEA方法和区间DEA方法相结合,建立农业企业绩效评价的模型,并利用DPS数据处理软件进行求解,然后对黑龙江省农业企业的内部绩效进行研究,进而找出农业企业内部绩效的影响因素,对其进行深入分析,最后提出农业企业内部绩效改进的方法策略。农业企业每个部门经营的绩效高,减少了农业企业各部门不必要资源的投入,提升了农业企业的内部绩效水平。     

地震时城市供水管网连通可靠性分析

在分析地震条件下管线功能函数及极限状态方程基础上,对城市供水管单元体进行震害预测。以供水管网系统作为边权的有向网络图,通过基于神经网络的Monte Carlo方法,模拟各管线运行状态及其破坏状态。结合图论理论,分析供水管网的管线连通可靠性。     

Prediction of the Economic Development for the Circumjacent Reservoir Region of the Longtan Hydropower Project Using Grey Quantitative Analog

In order to overcome some technical difficulties,we adopt ingenously the grey models combined with the quantitative analog method,and select the Dan Jiangkou Project which has accumulated practical operation data for a long time as the analog project to predict the economic influence for the circumjacent reservoir region of the Longtan hydropower project.On the basis of analog we have built various industrial economic grey models,and compare them with the corresponding predictions for the unconstructed reservoir case.The predictions of the former are greatly larger than the later ones.and hence provides a certain scientific basis for the central leaders to make a decision for constructing the huge hydropower project ultimateiy.     

INFLUENCE OF THE GEOMTRIC PARAMETERS OF LOW FINNED TUBE ON BOLHING HEAT TRANSFER AND OPTIMIZATION OF THE PARAMETERS

On the basis of the mechanism of the boiling heat transfer on low finned tube, the influence of the geometric parameters of low finned tube on boiling heat transfer is synthetically analyzed and relevant criteria which affect the optimal structure of low finned tube is deduced in this paper. The boiling heat transfer experiment on low finned tube is conducted. Distilled water and R-113 are used as test fluids The experiment is performed at local atmospheric pressure. Synthesizing a large amount of experimental data, the semiempirical equations for the optimal geometric parameters of lowfinned tube are established     

Artificial Neural Network Fault Diagnosis System Based on Rough Set Theory

On the basis of fault diagnosis neural network model, in this paper, knowledge representation system of rough set theory is taken as a major tool to delaminate the complex neural network and in which unnecessary properties are eliminated. This method overcomes some shortcomings, such as network scale is too large and the rate of classification is slow. The good effect that reduces the matching quantity of pattern search in classification course is gotten. The structure and algorithm of layered-mining neural network model based on rough set theory are also given. The example shows that this system has higher reference value in practical application.     

基于超静定方程的橡胶材料本构模型参数识别

由于橡胶材料具有非线性和大变形特性,使得描述橡胶力学特性的本构模型参数的确定比较烦琐和困难。为了提高橡胶本构模型参数识别的准确性,基于超静定方程求解原理推导出一种新的识别方法。以某橡胶衬套为例,识别的参数应用于有限元分析,对比试验数据,结果表明该识别方法可以准确识别橡胶材料参数,并且精度相对于最小二乘法有了明显改善,显示了超静定识别法的有效性和可靠性。     

A clustering algorithm based on link availability for MANET

The cluster topology management in the MANET network is studied in. The classic Lin-Gerla clustering algorithm is improved to increase the logical topological stability. By considering the node mobility in the communication systems, the notion of relative motion is introduced, and the nodes more stable are chosen as the cluster-heads, which effectively increases the stability of mobile network with Random Direction Model. Regarding the possible high concentration, a fast cluster splitting method is proposed for cluster maintenance. The simulation and performance analysis for the improved algorithm are given.     

农户社会网络关系评价体系设计及测算研究——基于1440份调查数据的分析

从网络规模、网络紧密度、信任与承诺、社会风气与归属感及社会参与5个方面构建评价农户社会网络关系的指标体系,按照区域分布,将所调查区域分为河套地区、中原地区和关中地区,采用实地调查的1440份农户数据,运用变异系数法确定各指标权重,进而对农户社会网络关系水平进行测算。研究得出：按照权重大小依次为社会参与、网络规模、网络紧密度、信任与承诺、社会风气与归属感;农户社会网络关系评价值整体较低,呈正偏态分布,且存在地区差异;关中地区最高,但个体差异明显,其次依次为河套地区和中原地区;从一级指标的测算结果看,社会参与得分最高,其次为社会风气与归属感、信任与承诺,最后为网络规模和网络紧密度,可见农户更愿意参与集体行动,人文环境得到进一步改善;地缘与亲缘限制了网络规模的扩大,而农村人口的流失也使得网络紧密度减弱。在此研究基础上提出相关建议,以期为相关政府机构实施乡村治理提供依据。     

Transient Simulation of Steam-turbine Generator Based on Time-domain

For achieving the high-fidelity simulation of steam-turbine generator on the real-time simulator of coal fired plant, the paper establishs a group of state equations based on Parkg equation, which can accurately describe its transient process. Then a kind of time-saved numerical solution in terms of four-order Runge-Kutta method is proposed through the modified processing to the time-dependent system matrix A and control matrix B. Finally a program is coded to simulate the emergency load process of one 360MW steam-turbine generator, the result indicates that the method of this paper can exactly apply on the generator model of real-time simulator.     

枫杨散生木优树选择研究

研究旨在有效利用枫杨优良遗传资源,建立枫杨散生木优树选择的方法体系,以期为挖掘枫杨遗传改良和开发利用提供科学依据。在野外广泛调查的基础上,建立江汉平原枫杨散生木年龄与胸径的回归方程为Y=0.737X 10.277。以初步选出的24株候选优树为对象,采用主成分分析法对年均生长量、高径比、枝下高、冠幅、冠径比、分枝角、树皮厚度和最粗分枝制定各性状的权重。结合初选优树的数量指标和形质指标,利用综合评分法评选出枫杨散生木优树6株,入选率为25%。建立的综合评分法为枫杨散生木优树选择提供科学方法。     

PROPERTIES OF HOMOGENEOUS FUNCTION AND ITS APPLICATIONS

This paper proves some properties of homogeneous function. Mainly, it proves that a sufficient condition of a parahomogeneous function is a subhomogeneous function. From which the relations of homogeneous function and partial derivatives of its respective variables are obtained. By these properties, this paper finally solves spcial first order total differential equations and obtains the quadrature of total differential of some function with n-variables. The obtained method of solution is simpler than usual one.     

Method of Computing Sinusoidal Steady-state Solutions of Lossy Uniform Transmission Lines

There is no universal method of finding the analytic solutions to transmission lines discribed by partial differential equations,so many researchers are studying and developing transmission line theories.Computing steady-state solutions of uniform transmission lines is one part of the study.The paper introduces another method of computing sinsoidal steady-state solutions of lossy uniform transmission lines.First,the complex expressions of voltage and current with zero initial state are obtained from the complex frequency-domain model of lossy uniform tansmission lines.The network functions,which are the ratios of voltage and current's image functions to the excitation's image function,can be found from the complex expressions.Sinusoidal steady-state solutions can be obtained by using the relation between network function and system's frequency characteristic.Finally,the method is demonstrated to be effective by an example.     

Galerkin Boundary Element Method for Laplace Equation

Galerkin method based on the variation principle is used to solve differential and integral equations. The boundary problem of Laplace equation is changed into the variational equation which is equivalent to the boundary integral equation. Using linear element, it is solved by Galerkin boundary element method. In computation of stiffness matrix, the exactly integral formula is used in the first order integral expression, The numerical integral formula is used in the second order integral expression. Thus the problem of calculation of double singular integral is carried out. The numerical experiments also prove this method is reliable. The error of Galerkin boundary element is tested with numerical experimentation.