高阶多段凸轮型线的拟合方法研究及软件开发

探讨了高阶多段凸轮型线的拟合方法，分析了其中的分段、光顺、拟合和病态矩阵求解等关键技术，着重讨论了正交基的最小三乘拟合方法，开发了一个高阶多段复杂凸轮型线的拟合软件，并以实例测试了该拟合软件的正确性。     

一种基于最小二乘的不完整椭圆拟合算法

研究了一种基于最小二乘的不完整椭圆拟合算法。基于几何距离的拟合算法可达到较高的拟合精度，但迭代过程敏感于初始条件；由于不完整的椭圆样本点及噪声的存在，简单线性拟合方法可能使拟合结果退化为开放的双曲线，引起拟合失败，基于椭圆约束的代数距离拟合方法可保证拟合结果一定是椭圆，从而为迭代提供适当的初值；利用多个待估计椭圆参数之间的相互约束，即使非常短的椭圆弧也可得到稳定的拟合结果。仿真结果与实际图像应用验证了算法的有效性。     

基于鞍点规则的复杂刀具齿形拟合

给出了鞍点规划的概念，阐明了鞍点规划的基本原理，建立了运用鞍点规划理论解决齿形拟合问题的一数学模型，实际拟合结果表明，这种方法具有拟合误差均匀性好、精度高的特点。     

基于截面数据的B样条曲面光顺拟合

分析了B样条曲线的光顺拟合方法，针对按截面测量所得数据，将B样条曲线光顺拟合的方法扩展到B样条曲面的光顺拟合，并给出了数值算例。     

基于鞍点规划的复杂刀具齿形拟合

给出了鞍点规划的概念，阐明了鞍点规划的基本原理，建立了运用鞍点规划理论解决齿形拟合问题的统一数学模型。实际拟合结果表明，这种方法具有拟合误差均匀性好、精度高的特点。     

三次参数曲线拟合圆弧段的误差特性分析

建立了拟合任意圆弧的三次参数矢量方程。在此基础上，用数学分析的方法从理论上证明了拟合半径函数与圆弧位置无关，最大误差处参数值与圆弧大小和位置均无关这两大拟合特性，并提供了常用圆弧段被拟合时的最大误差值。     

非圆曲线的最小拟合误差逼近法

提出并论证了一种用直线拟合非圆曲线的新方法──最小拟合误差逼近法，它具有拟合误差小，节点数少，计算和编程简便的特点。     

某种炮钢材料磨损规律的神经网络泛化拟合研究

用神经网络泛化拟合的方法对试验数据进行处理，提出了泛化拟合准则，借助BP神经网络分别用小隐层单元法、检验样本法和贝叶斯调整法对实验数据进行泛化拟合，结果表明，贝叶斯调整法效果较好，可用于该种炮钢材料磨损规律的工程拟合。     

基于数据几何分析的新数据拟合模型与算法

首先介绍了多种数据拟合的几何标准，然后从数据的几何分析出发，给出了求夹空间数据点集的最窄超平面对算法，并针对数据拟合几何标准推导出了基于数据几何分析的新数据拟合模型。     

轴线测量中的曲线拟合方法比较研究

简要介绍了轴线测量时几种曲线拟合方法，比较了不同拟合方法在应用中的具体特点，并模拟实际检测情况进行实验研究；同时讨论了拟合方法的基本选用原则，并总结了对拟合方法进行比较研究的一些结果。     

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.     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.