基于主成分回归的苹果可溶性固形物含量预测模型

为了更好地预测苹果的可溶性固形物含量（SSC）,试验采用反射式光谱采集系统获取采后“富士”苹果的光谱反射率。分析了3种光谱预处理方法（标准正态变换、多元散射校正以及二阶导数）对预测模型的影响;利用主成分分析方法对预处理后的光谱数据进行降维,并基于选取的特征变量建立预测苹果SSC的回归模型。结果表明：采用主成分分析方法从全光谱的1 024个波长中选取了前23个主成分得分作为特征变量;基于特征变量建立的回归预测模型具有较好的预测能力,其预测集相关系数RP=0.908,均方根误差RMSEP=0.499。这表明采用光谱技术结合主成分回归预测苹果SSC是可行的。     

A New Method of Diesel Engine Fuel System Fault Diagnosis

A method of diesel engine fuel system fault diagnosis based on wavelet transform and fuzzy C-means clustering is presented. Five characteristic parameters of reflecting fault state are distilled with wavelet transform of pressure wave of high-pressure oil pipe of diesel. The theory and generic approach of fuzzy C-means clustering algorithm (FCM) is given, and the validity of evaluating fuzzy clustering making use of partition coefficient, partition entropy and parting coefficient is pointed out. Identification of fault mode can be completed utilizing standard fault character modes established by FCM algorithm, and calculating and comparing the similarity degree between this standard mode and sample. The arithmetic is applied to all kinds of typical faults diagnose in the diesel engine fuel system. Measuring results indicate that the precision of fault diagnosis is increased with the analysis of wavelet and FCM.     

Housing Project Hedonic Price Model Based on Principal Components Analysis

Real estate hedonic price model is applied to determine the average sale unit price of newly built housing projeer. In order to solve the problems of the lack of sample and the high correlation of some of the housing characteristic factors with each other in this application, a housing project hedonic pricing model based on principal components analysis of housing characteristic factors has been established. Through a case, the author has analyzed the economical significance of the implicit prices. With the model, the average sale unit price of a newly built housing project can be determined by rule and line.     

Power model and tarepower characteristic of CNC machine tool feed system

A power model of a CNC machine tool feed system is proposed based on analyzing the power characteristic of each component in the CNC machine tool feed system. And the tarepower characteristic and its dominant affecting factors are analyzed by using the power model. The analysis results show that the tarepower of feed system is a monotone increasing quadratic function in term of the feed speed. Meanwhile, the feed speed and load mass both affect tarepower, but the influence of load mass is minuteness. Some experiments are conducted on a 3-axis CNC milling and the experimental results justify the theoretical analysis.     

THE NEW PHASE SELECTION SCHEMES ON USE OE FAULT COMPONENT

In accordance with the characteristic of digital relay and fault locatoin four methods of phase selection on fault component are presented in this paper.These methods are simple in principle, reliable in action, and immune from load flow,system oscillation.Hardly affected by fault location, source impedance and fault resistance, they can select fault phase reliably for any power system and fault type.As phase selection schemes, they can be used for perfect digital relay.     

Analysis of Interpolate-compensation Component of Open CNC System Based COM

CNC system is gradually developing toward flexible, component modular and re-configurable of open CNC system's structure. It's beginning a research direction in open CNC system with the software reuse and re-configurable technology. Based on the expound of concepts and characteristics of component technology, open CNC system's characteristics are analyzed based on COM and open CNC system is divided into several components. With the characteristics of binary language irrelevant, thread transparent, re-configurable and normative interface of COM technology, open CNC system's interpolate-compensation component in interpolate-compensation component achieved, interface designed and object created are researched. Better effects are achieved by connecting the interpolate-compensation component with the other CNC components. At the same time, the CNC component's real-time control problem is analyzed.     

采动影响下逆断层特征参数对断层活化的作用规律

笔者分析了采动影响下断层滑移的主要影响因素,以数值模拟为研究手段,利用FLAC 3D建立了逆断层简化模型,分析了不同断层倾角、不同落差及采掘工作面与断层不同距离的断层带附近煤岩体弹性能、断层面正应力与剪应力、断层滑移量的变化规律,从而揭示了采动影响下逆断层特征参数对断层活化的基本作用规律。研究结果表明：上盘或下盘开采,断层带附近煤岩体弹性能集中程度随工作面与断层距离的增大而降低,随断层倾角及落差的增加而增大,但下盘开采对断层带的能量集中程度较上盘高。下盘开采时剪应力较上盘显著增加,但正应力变化较小,易于断层活化。上盘或下盘开采,随工作面与断层距离的增加,断层滑移量减小。上盘开采,随断层倾角增大,断层滑移量增加;随断层落差增大,断层滑移量减小。下盘开采,随断层倾角增大,断层滑移量减小;随断层落差的增大,断层滑移量增加。     

超甜玉米自交系主要农艺性状及鲜穗产量的主成分分析

为了研究影响超甜玉米鲜穗产量和主要农艺性状间的主次关系,应用多元统计方法,以30个超甜玉米自交系为试验材料,对株高、穗位高、叶片数、茎粗、秃尖长、穗长、穗粗、穗行数、行粒数、百粒重、出籽率、鲜穗产量等12个性状进行主成分分析。分析结果表明,前7个主成分的累计贡献率大于85%,说明前7个主成分就可以基本表达原12个性状所代表的遗传特征。前7个主成分主要包括产量因子、穗行数因子、穗粗因子、粒重因子、株高因子、茎粗因子和秃尖长因子,这些因子大致代表了供试自交系的综合指标,为超甜玉米自交系的性状综合选择提供了依据。     

Entropy Generation Analysis of Heat Transfer Process through a Duct

Based on the first and the second laws of thermodynamic, the entropy generation of heat transfer process from the inside to the outside through a duct is analyzed. A dimensionless entropy generation number based on the fluid of inside duct is introduced and an analytical expression for the dimensionless entropy generation number is obtained. The effect of some dimensionless parameters on the irreversibility performance of heat transfer process through a duct is discussed. The results show that an optimal Reynolds number of fluid inside duct is found to make dimensionless entropy generation number minimum , the dimensionless entropy generation number increases with the increment of the ratio of the Reynolds number of inside and outside duct fluids, dimensionless inlet temperature difference and dimensionless characteristic geometric dimension. The results from this paper provide a reference for the thermodynamic performance evaluation on the basic heat transfer process through a duct and enhancement in double sides of duct.     

Kolmogorov entropy analysis of surrounding rock system in the processing of unloading for deep buried tunnels

Rock is a kind of physical nonlinear complicated medium, under deep buried condition the surrounding rock system deformation shows geometrical nonlinear characteristic, and the interaction between the two nonlinear mechanism makes the unloading of surrounding rock system evolving complexly. Based on the Lagrangian method and large deformation caculation method, both the double nonlinearity and nonlinear dynamics character of deep buried tunnel surrounding rock system under unloading are studied. The numerical model results show that the Kolmogorov entropy has been extracted from the evolution data in the unloading process of surrounding rock system. The analysis indicates that the typical chaos character has been demonstrated in the process of unloading for deep buried tunnel surrounding system and the rock mass energy dissipation is analyzed at the stage of unloading.     

Study on the Method of Intelligence Fault Diagnosis System for Drill

It is very difficult to simulate the motion process of drill by accurate mathematics model for the complexity and invisibility of stratum. The fault of drill is usually identified and disposed by personal experience so far. This means it can not estimate the trend of the equipment running good or not and the reason conduced the fault or location and degree of fault by data measured. Farther, it can not give the expert suggestions. Based on the studying of drill fault, artificial intelligence and expert system have been used in the petroleum drilling engineering, the theory and method of fault diagnosis intelligence system for drill have been studied. It also constitutes the expert knowledge database of graphic Fuzzy Neural Network for the familiar fault of drill. The intelligence reasoning machine which consists of expert rule, Fuzzy logic and artificial Neural Network have been bring forward. And the fault diagnosis system it makes for drill can be applied in complex system which includes multi-variable, multi-parameter and multi-process.     

基于信息熵的庄浪县土地利用结构变化及其驱动力分析

为研究庄浪县土地利用结构动态变化情况,促进土地资源的合理利用和可持续发展,基于庄浪县1997—2012年土地利用变更数据以及经济社会统计数据,采用信息熵、均衡度和优势度原理,分析庄浪县土地利用结构的动态演变特征,并运用主成分分析方法对影响庄浪县土地利用结构动态演变的驱动力进行分析。结果表明：1997—2012年,庄浪县土地利用结构信息熵总体呈先上升后下降再上升的波浪式趋势变化,表明各区域的土地利用系统仍处于较大程度的开发中。耕地、林地及未利用地面积所占比例的高低,是影响庄浪县土地利用结构信息熵的主要因素。人口经济发展状况、城市化、产业结构是庄浪县土地利用结构变化的主要驱动力。     

EQUIVALENT CIRCUIT METHOD FOR DYNAMIC DIGITAL SIMULATION OF HVDC CONVERTERS

This paper presents a transient mathematical model of the HVDC converters-Equivalent Circuit Method(ECM), which can describe all possible states of converter valves in a simple and explicit way. With the converter model, programs have been implemented for single and double bridge HVDC systems. The results of simulation to the normal and fault operation of HVDC system show that the method is flexible and reliable, and has the advantages of small calculation amount and less computer storage requirments. The programs based on this paper provide convenient, inexpensive and feasible tools for computer dynamic or transient analysis of the HVDC systems.     

Partition Algorithm of Power Network Based on the Optimum Clustering Principle

The paper construct the specimen of multi-dimensional space based on the definition of clustering, calculate the generator control sensitive to load and the Eulerian distance, partition the power system by the shortest distance method of clustering analysis. After the range of area num-ber is determined, the optimal area number and its validity is decided by Shannon function of entropy and Sugeno-Yasukaw rule. A case of IEEE 39-bus system is presented to verify the method.     

Design and Realize Intelligent Decision Support System of Rocket Safety Control

The problem on rocket safety control is important during the rocket launching proceeding, and is also the focus of every space country. The importance of rocket safety control is introduced, and the characteristics of the existing system are analyzed. Because of the special characteristics, the paper proposes an intelligent decision support system of rocket safety control, adopting the technique of artificial intelligent especially expert system. First, the authors introduce rocket safety control architecture and function. Then, a new method is proposed to represent the knowledge which is integrated with production rule and object-oriented technique. Furthermore, the reasoning is investigated, and decision-making network and uncertainty reasoning model are introduced.     

Knowledge Representation for Rotative Machine Fault Diagnosis Based on Semantic Net

Aiming at knowledge representation problem of expert system for rotary machinery fault diagnosis, semantic net knowledge representation is discussed. Semantic net to represent expert knowledge of rotary machinery fault diagnosis is explored. Its realizing method is afforded in computer language, in addition, demostrating model is also developed in Visual C++. The result shows good validity of the knowledge representation.     

EPC contract dispute alert and case analysis

When the EPC contract dispute occurs, complex relationship is usually involved, contract claim amount is large, and the consequence of hindering a contract is serious. Therefore, in order to prevent, warn and track disputes, based on some information with strong signs showing disputes, this study establishes a case based reasoning and rule based reasoning (CBR+RBR) model with qualitative and quantitative integration by synthetically using reasoning theory, rough set theory, the entropy method and Euclidean distance retrieval method to prevent and warn possible disputes and realize real-time tracking. By collecting related cases and establishing case databases, we use the CBR+RBR model to analyze various factors may cause EPC contract disputes, and through case analysis to validate that the model can warn EPC contract disputes.     

An edge detection method based on a good point set genetic algorithm

In order to improve the convergence rate of genetic algorithms based on edge detection, a novel edge detection method based on a good point set genetic algorithm (GGA) was proposed. The proposed method designed the crossover operation with the theory of good point set in which the progeny inherits the common genes of the parents which represent its family so as to improve the convergence rate of the genetic algorithm. Furthermore, before the algorithm was used for edge detection, the feature space of the image grey level was transformed into the feature space of the fuzzy entropy. Dissimilarity enhancement processing next was applied to the image by using a fuzzy entropy theory to filter the non edge pixels so as to reduce the scale of the solution domain. This approach offered another efficient way to improve the convergence rate. Experimental results show the proposed algorithm performs very well in terms of convergence rate. The detected edge image is well localized, thin, and robustly resistant to noise.     

基于信息熵的土地利用结构变化影响因素分析——以重庆市丰都县为例

开展县域土地利用结构研究,用定量方法分析县域土地利用现状及其主要问题,有助于促进土地的合理利用和可持续发展。笔者应用熵值函数模型和灰色关联分析,对重庆市丰都县土地利用结构熵与社会经济发展关联性进行分析。结果表明,过去12年丰都县土地利用结构熵呈近似S型曲线增长态势,土地利用系统无序性增加,均质性增强。人口压力、产业结构调整是影响土地利用结构信息熵变化的主要因素,社会固定资产投资和逐步加强的政府行为成为促进土地结构均衡的新动力,旅游产业的发展成为促进土地结构熵变化的潜在动力。     

基于小麦籽粒高光谱特征的品种鉴别研究

为探究高光谱成像技术在小麦籽粒品种鉴别等的研究,以15种品种已知的小麦籽粒为对象,分别采集样品的光谱和图像信息。运用主成分分析法优选三个特征波长(447nm、615nm、955nm),提取特征波长下小麦籽粒图像的形态特征(面积、周长、圆度、长轴长度、短轴长度)和纹理特征(均值、标准差、熵)。应用Bayes判别分析法进行多元统计分析,建立判别函数判别回代准确率为99.9%,交叉验证的准确率为98%,模型的判别效果良好。研究表明利用高光谱成像技术结合Bayes判别分析的方法可用于小麦籽粒品种的鉴别。