一种基于分布式数据仓库的文件集快速更新算法

异构数据源整合是企业数据共享的前提，而高效的数据更新不仅节约系统开销还能提供实时数据。在分布式数据仓库的数据预处理区快速更新变动的数据是一个非常重要的热点问题，利用增量文件集的快速更新算法进行ETL设计可以加快数据更新的速度，消除异构数据模式的不一致和语义冲突问题，成套电器集团公司的成功应用证明了该算法的有效性。     

基于模糊C均值聚类算法的海洋环境监测研究

该文将模糊C均值聚类算法(FCM)应用到海洋环境监测数据的挖掘中。应用数据预处理算法,对莱州湾海域的历史海洋数据包括p H值、温度、溶解氧浓度等进行处理;应用FCM算法对不同海域的数据进行聚类,以此获得相近海域的数据特征;将该算法应用到海水污染预警中,用于区分污染和未污染海水样本。实测结果表明了算法的有效性,为海水污染预警提供了一种新的思路。     

决策树在发动机试车数据库数据挖掘中的应用

如何正确的对缺失数据进行填充是数据挖掘预处理过程中的一个重要问题。这里给出了一种基于决策树来解决此问题的算法。该算法应用改进的ID3算法来构造决策树，利用决策规则对缺失值进行补充。在构造决策树之前，采用属性约简技术得出条件属性集，使得决策树简单，并且计算速度得到提高。此算法应用在某型发动机试车数据库中，被证明是可行的、高效的。     

面向半导体制造的大数据分析平台

为充分利用半导体制造过程产生的大量数据,发掘数据中蕴含的价值,对半导体制造过程进行分析、预测和调控,建立了半导体制造大数据分析平台。归纳得出了半导体制造过程中大数据的特性,提出了半导体制造大数据分析体系架构,分析了其关键技术和实现方法。根据半导体制造过程中大数据的使用特点,将数据导入、去重、筛选、标准化等共性操作归入平台通用预处理层;预处理后的数据进入数据仓库层,在数据仓库中按主题进行组织;最上方的专用处理算法层根据上层应用的特定数据要求,从数据仓库中抽取数据,使用专用算法进行处理,为其提供标准化、可靠、可复用的数据资源。最后基于半导体制造企业的实际情况搭建了原型系统,对半导体制造过程产生的大量实际数据进行导入、存储、组织和预处理,并进行了性能测试和常用统计分析算法测试。     

虚拟齿轮测量中心工件模型预处理算法研究

在虚拟齿轮测量中心对复杂模型进行测量时,存在大量碰撞检测数据,提出一种碰撞检测前对模型表面数据提前预处理的方法。该方法采用空间体素数据结构算法思想,使测头能够准确获得有可能发生碰撞的模型表面数据,相比于原有遍历式扫描检测算法,避免了频繁计算测头到模型各个三角面片的距离,提高了算法效率。结合开发的虚拟齿轮测量中心软件系统进行预处理算法的测试评估,通过试验验证了预处理算法的可行性和正确性,最终实现了工件模型预处理功能。     

使用PCA及SVM算法进行滚动轴承故障检测

本文使用PCA（主元分析）算法对滚动轴承振动信号数据进行预处理,这可降低数据维数和提取数据特征信息;将预处理后数据作为SVM（支持向量机）算法的输入,通过SVM算法来检测轴承故障。     

基于优化核空间的制造过程质量分析算法

为帮助制造企业处理积累的海量制造过程质量数据,数据挖掘方法可以帮助企业从中发现有用的知识和模式进行有效的质量分析及改进。制造过程质量数据的特点如下：混合型数据、分布不均衡、维度灾难及数据耦合。提出一种基于等价关系的数据预处理算法对原始数据做属性选取,解决混合型数据的特征选取及数据预处理问题。针对数据分布不均衡、维度灾难特点,提出基于优化核空间的混合流形学习及支持向量机算法(Optimized kernel based hybrid manifold learning and support vector machines algorithm, KML-SVM)。在KML-SVM算法中,使用流形学习算法解决采集的质量数据的维度灾难问题,用支持向量机对低维嵌入数据分类预测,并优化支持向量机的核空间以达到分类精度最大化。以某制造企业实际制造过程数据为例对算法进行仿真验证。通过对仿真结果的分析找出质量数据的质量因素关系并提出质量改进方案。试验结果表明提出的ISOMAP核空间是最优核空间,提出的KML-SVM算法能够有效处理制造过程质量数据。     

数据预处理技术和机器学习方法在质子转移反应质谱中的应用

质子转移反应质谱（PTR-MS）法是一种用于检测挥发性有机物（VOCs）的分析技术。它具有检测限低、响应速度快、无需样品前处理、实时分析等特点,在大气化学、环境化学、食品、生物医学等领域得到广泛应用。随着PTR-MS应用的扩展和样品种类的增加,如何从复杂的质谱数据中提取特征,并寻找内在规律,对分析算法的处理能力提出了更高的要求。本工作从数据预处理技术和机器学习方法两方面展开论述,归纳了具有PTR-MS特点的数据预处理技术,总结了不同机器学习算法在PTR-MS数据分析中的应用,并讨论了它们的优点和不足。     

分离式数字记录装置的两种记录算法

针对一种分离式数字记录装置，详细描述并比较了两种数据记录算法，且给出了一组典型实验结果，在某些应用场合，用方法二可以获得较长的数据记录时间。     

电容层析成像图像重建中的迭代算法

电容层析成像技术中图像重建算法的准确与快速是其在工业实际中得以应用的关键。Landweber方法是一种简单、灵活的迭代算法，具有很好的正则化特性，它的投影变体能够提供非负的图像重建。Landweber算法实际应用的困难是其收敛速度太低。本文采用预处理方法来加快Landweber迭代方法的收敛速度，即通过较少的迭代次数，获得适当的重建结果。仿真实验表明，同经典的快速算法共轭梯度迭代方法相比，预处理Landweber迭代方法具有更好的重建图像质量。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.