精密机床床身结构参数的优化设计

在确定精密机床床身合理结构的基础上，利用ANSYS有限元软件提供的APDL参数化设计语言和优化设计方法，以床身的肋板布置和肋板厚度为设计参数，对床身进行结构设计参数的优化，确定了床身结构的合理参数。不仅大大提高了床身的动态性能，而且节省了材科，降低了生产成本。     

精密丝杠选材及热处理工艺研究

本文对用于大中型精密测试测量仪器的传动丝杠在制造过程中材料选择和热处理工艺进行了调查和总结,对关键零件的工艺过程提出了修改建议。     

基于改进SVM的网络流量分类方法研究

针对网络环境中存在大量噪声和网络流量中存在过多的冗余特征属性,提出了一种具有特征有效度的模糊支持向量机(FW-FSVM),并将FW-FSVM应用于网络流量分类领域。该方法根据不同样本点对分类贡献的大小赋予相应的模糊因子,可以有效地消除噪声对分类精度的影响;同时计算网络流量中各个特征的有效度,消除弱特征属性或冗余特征属性对网络流量分类精度的影响。实验结果表明,FW-FSVM相比于其他网络流量分类方法能有效地提高网络流量分类精度且分类稳定性较高。     

A flexible classification method for evaluating the utility of automated workpiece classification system

In group technology, workpieces are categorised into families according to their similarity in design or manufacturing attributes. This categorisation can eliminate design duplication and facilitate the production of workpieces. Much effort has been focused on the development of automated workpiece classification systems. However, it is difficult to evaluate the utility of such systems. The objective of this study was to develop a benchmark classification system based on global shape information for use in evaluating the utility of workpiece classification systems. A classification system has a high level of utility if its classification scheme is consistent with users' perceptual judgment of the similarity between workpiece shapes. Hence, in the proposed method, the consistency between a classification system and users' perceptual judgements is used as an index of the utility of the system. The proposed benchmark classification has two salient characteristics:

工程材料选用方法研究现状及发展趋势

从工程材料选用的原则及方法出发，概述了近年来选材工作的研究进展，列举了现代选材在工程中的具体应用实例，加深对材料选择研究领域的理解。并对材料选用研究作了展望。     

一种新型的实时计量系统的开发与应用

介绍了一种新型的高精度、高频率的实时计量系统。该系统的特点是将动态计量转换为静态计量，较完善地解决了实时、高速、在线计量系统中的精度问题。该文着重阐述了关于系统的设计新思路、新结构、新功能、新特点及系统的结构组成等。     

基于树型贝叶斯网络的场景分类引擎训练算法

贝叶斯网络在场景分类统计模型设计中得到广泛的应用.但现有的大部分贝叶斯网络场景分类引擎没有能够充分利用贝叶斯网络丰富的知识表现能力和有效的自动学习能力.首先提出了一种灵活的树型贝叶斯网络分类引擎,用于场景分类模型的设计.然后,以条件对数似然评价为标准研究这种模型的自动学习方法,通过对分类器等价类的研究,证明了树型贝叶斯网络分类引擎自动训练过程可以忽略网络中边的方向,并提出了一个不需要对边重定向的学习算法.由于通常的场景图像编码维度较高,省略了边的重定向过程能够有效地减少模型的训练时间.实验结果验证了所提算法的平均训练时间在基准场景图像库上比传统算法的减少23.32％.     

混流装配线物料配送仿真与优化

混流装配线的准时制物料配送对Makespan有着显著影响.利用Plant Simulation仿真软件建立了一般MTO企业混流装配线的物料配送系统仿真模型,建立了配送系统参数对Makespan影响的数学模型.通过仿真试验设计的方法,优化配送系统中的搬运小车的数量及速度、装载量大小及线边暂存区最大最小库存量.     

压力容器用复合材料的性能与应用

压力容器应用广泛,但存在很大危险性,选材是压力容器设计制造中的关键因素。本文从复合材料的特点、应力分析、失效和设计等方面,阐述复合材料在压力容器中的应用性能和设计制造方法。     

铜基复合制动材料摩擦磨损性能研究进展

我国高速列车的不断提速,对制动盘材料的性能提出了更高的要求。铜基复合制动盘材料由于具有高比刚度、高比强度、优良的高温性能,以及良好的摩擦磨损性能等优点,被认为是最有应用前景的制动盘材料。在介绍高速列车制动盘材料发展的基础上,进一步论述了铜基复合制动盘材料的构成组元、制备方法及发展历程;阐述了铜基复合制动盘材料摩擦磨损性能的研究现状;最后展望了铜基复合制动盘材料的发展趋势,为高性能铜基复合制动盘材料的研制提供参考。     

梯度功能材料非定常热传导的形状效应

采用分离变量法和变量代换法,推导出无限大平板、无限长圆柱体和圆球体3种形状的梯度功能材料构件在第三类边界条件下的量纲一非定常温度场的解析解。3种形状的梯度功能材料构件的组分和热－物理性能分别服从平面对称、轴对称和球对称分布规律。通过数值计算并与无限大平板、无限长圆柱体和圆球体3种形状的均质构件对比,研究梯度功能材料构件形状以及热－物理性能分布对非定常热传导的影响。计算结果表明,梯度功能材料构件的非定常热传导具有与均质构件相似的形状效应,即圆球体的温度传播速度最快,而无限大平板的温度传播速度最慢。由表及里增大梯度功能材料构件的热导率和热扩散率,可提高温度传播速度。     

制造缺陷对复合材料性能的影响研究

复合材料在制造过程中不可避免地会出现胶接分层、制孔分层等制造缺陷,分层损伤作为复合材料重要的损伤形式,严重影响了复合材料力学性能特性。本文对含预制缺陷复合材料开展了多种力学性能试验研究,通过与完好复合材料进行对比分析,建立了制造缺陷对复合材料性能的影响规律,可为复合材料结构设计提供支撑。     

An efficient method for creating benchmark classifications for automatic workpiece classification systems

The usefulness of an automatic workpiece classification system depends primarily on the extent to which its classification results are consistent with users' judgments. Thus, to evaluate the effectiveness of an automatic classification system it is necessary to establish classification benchmarks based on users' judgments. Such benchmarks are typically established by having subjects perform pair comparisons of all workpieces in a set of sample workpieces. The result of such comparisons is called a full-data classification. However, when the number of sample workpieces is very large, such exhaustive comparisons become impractical. This paper proposes a more efficient method, called lean classification, in which data on comparisons between the samples and a small number of typical workpieces are used to infer the complete classification results. The proposed method has been verified by using a small set of 36 sample workpieces and by computer simulation with medium to large sets of 100 to 800 sample workpieces. The results reveal that the method could produce a classification that was 71% consistent with the full-data classification while using only 10% of the total data.     

基于机器视觉的汽车换挡面板自动分类方法

针对报废汽车企业对不同型号汽车换挡面板自动分类的需求,提出了一种基于机器视觉的面板自动分类方法.该方法首先使用Blob分析对图像进行预处理,分割出图像中的换挡面板目标对象,接着提取被分割图像的11个形状特征作为特征向量,利用特征向量训练多层感知器(Multi-Layer Perceptron,MLP),最后使用完成训练...     

An artificial immune algorithm for ergonomic product classification using anthropometric measurements

Product classification using anthropometric measurements leads to ergonomic product design and user satisfaction. We propose an effective artificial immune algorithm (AIA) to classify ergonomic products with multi-criteria anthropometric measurements and tune the AIA parameters with a full factorial experimental design approach. We demonstrate the applicability and efficacy of the proposed algorithm by considering the anthropometric measurements of the hand, developing an ergonomic computer mouse, and classifying consumers into three categories. The resulting classifications are compared with expert opinions to facilitate the conformity of the computer mouse to user requirements.     

活齿传动分类方法及结构改进新思路的探索

从机构学出发寻找活齿传动形式的共同特征并对其进行分类,并在此基础上提出了活齿传动性能改善和结构改进的新思路,对活齿减速器及其活齿传动机构的研究发展具有重要的指导意义.     

砷料送料机的螺旋输送机的设计

为满足砷料送料机工作的要求,采用螺旋输送机构进行精确送料,对此工况下所要求的螺旋输送机结构进行设计与计算,对其驱动装置做了深入设计,保证了砷料的精确送料,提高了设备的生产效率。     

Precision design for machine tool based on error prediction

Digitization precision analysis is an important tool to ensure the design precision of machine tool currently.The correlative research about precision modeling and analysis mainly focuses on the geometry precision and motion precision of machine tool,and the forming motion precision of workpiece surface.For the machine tool with complex forming motion,there is not accurate corresponding relationship between the existing criterion on precision design and the machining precision of workpiece.Therefore,a design scheme on machine tool precision based on error prediction is proposed,which is divided into two-stage digitization precision analysis crucially.The first stage aims at the technology system to complete the precision distribution and inspection from the workpiece to various component parts of technology system and achieve the total output precision of machine tool under the specified machining precision;the second stage aims at the machine tool system to complete the precision distribution and inspection from the output precision of machine tool to the machine tool components.This article serves YK3610 gear hobber as the example to describe the error model of two systems and basic application method,and the practical cutting precision of this machine tool achieves to 5-4-4 grade.The proposed method can provide reliable guidance to the precision design of machine tool with complex forming motion.     

Processing and classification of protein mass spectra

Among the many applications of mass spectrometry, biomarker pattern discovery from protein mass spectra has aroused considerable interest in the past few years. While research efforts have raised hopes of early and less invasive diagnosis, they have also brought to light the many issues to be tackled before mass-spectra-based proteomic patterns become routine clinical tools. Known issues cover the entire pipeline leading from sample collection through mass spectrometry analytics to biomarker pattern extraction, validation, and interpretation. This study focuses on the data-analytical phase, which takes as input mass spectra of biological specimens and discovers patterns of peak masses and intensities that discriminate between different pathological states. We survey current work and investigate computational issues concerning the different stages of the knowledge discovery process: exploratory analysis, quality control, and diverse transforms of mass spectra, followed by further dimensionality reduction, classification, and model evaluation. We conclude after a brief discussion of the critical biomedical task of analyzing discovered discriminatory patterns to identify their component proteins as well as interpret and validate their biological implications.     

Development of an inexpensive, high-accuracy diamond turning machine

A small, numerically controlled, two-axis diamond lathe for parts up to 100 mm diameter has been assembled from commercially available components in two weeks. The machine has exceeded performance expectations; in a test of its accuracy, 25.4 mm diameter hemispherical aluminium parts were cut to an accuracy of 0.25 μm (size and contour band) with a surface finish of 25–40 nm rms