基于模糊MARS的入侵检测系统

多元自适应样条回归是一种有效的针对高维数据回归建模方法,将该算法应用于入侵检测系统,根据入侵检测中存在的噪声数据和异常数据问题,提出了基于模糊算法的多元自适应样条回归方法。通过基于KDD1999数据集的训练和测试,与SVM在数据集上的测试结果进行对比,得出结论:该算法在入侵检测应用方面优于SVM算法。     

曲面光顺的分片能量法

能量法是一种目前被广泛采用的光顺方法,但当数据点较多时,能量法的存储量和计算量都很大。本文研究Ｂ样条曲面光顺的分片能量法。应用该法可以在保持光顺效果的能量法基本一致的前提下,大大地减少了存储量和计算量。实例表明,这是一种行之有效的曲面光顺方法。     

贝叶斯多元线性样条在电力负荷中期预测中的应用

贝叶斯多元线性样条BMLS是基于贝叶斯框架下的分段线性回归技术,实现了回归面边界光滑性.本文分析了BMLS方法的原理,结合EUNITE网络2001年举办的电力负荷预测比赛提供的数据进行了相关数据分析,建立了相应的电力负荷中期预测模型.我们使用BMLS方法对两种训练样本集进行了训练,并计算出预测期的预测值,取得了理想的预测结果,并结合其它方法对试验结果进行了分析.文章最后总结了BMLS方法用于预测的特点,并与其它方法,如相关向量机等进行了比较.使用BMLS的模拟近似平均技术进行预测可以实现较好的精度.     

渐开线花键公法线长度测量值及其公差的计算

介绍了常用的中国GB T3478.1、美国ANSB92 .1和德国DIN5 480三种渐开线花键公法线长度的理论值、跨齿数(或跨齿槽数)及其上下偏差的计算方法,并对有关标准中相关数据查找的具体使用方法作了简明扼要的介绍。     

High‐quality rendering of smooth isosurfaces

Animation and visualization of rectilinear data require interpolation schemes for smooth image generation. Piecewise trilinear interpolation, the de facto standard for interpolating rectilinear data, usually leads to significant visual artifacts in the resulting imagery. These artifacts reduce the confidence in the resulting visualization and may even lead to false interpretations of the data. This paper is concerned with the generation of smooth isosurface image sequences, obtained by casting rays through the image plane and computing their intersections with an isosurface. We describe a novel solution to this problem: we replace trilinear interpolation by tricubic interpolation, smoothing out the artifacts in the images; and we simplify the ray–isosurface intersection calculations by rotating and resampling the original rectilinear data in a second rectilinear grid—a grid with one family of grid planes parallel to the image plane. Our solution significantly reduces artifacts in individual images and leads to smooth animations. Copyright © 1999 John Wiley & Sons, Ltd.     

Finite strip buckling and free vibration analysis of stepped rectangular composite laminated plates

A general spline finite strip method is presented which allows the spline knots to be located arbitrarily along the plate strip and also facilitates the use of analytical integration in evaluating strip properties. The development takes place in the contexts of first‐order shear deformation plate theory and of classical plate theory, and encompasses composite laminated material. The prediction of natural frequencies and buckling stresses of stepped rectangular plates is considered using the new approach in which refinement of knot spacings is used local to a step change. The superstrip concept is used as part of an efficient solution procedure. A number of applications demonstrate the validity and practicability of the developed method. Copyright © John Wiley & Sons, Ltd.     

A numerical solution of nonlinear parabolic-type Volterra partial integro-differential equations using radial basis functions

In this paper, an effective numerical method for solving nonlinear Volterra partial integro-differential equations is proposed. These equations include the partial differentiations of an unknown function and the integral term containing the unknown function which is the “memory” of problem. This method is based on radial basis functions (RBFs) and finite difference method (FDM) which provide the approximate solution. These techniques play the important role to reduce a nonlinear partial integro-differential equation to a linear system of equations. Some illustrative examples are shown to describe the method. Numerical examples confirm the validity and efficiency of the presented method.     

Multivariate Adaptive Regression Splines Model to Predict Fracture Characteristics of High Strength and Ultra High Strength Concrete Beams

This paper presents Multivariate Adaptive Regression Splines (MARS) model to predict the fracture characteristics of high strength and ultra high strength concrete beams. Fracture characteristics include fracture energy (GF), critical stress intensity factor (KIC) and critical crack tip opening displacement (CTODc). This paper also presents the details of development of MARS model to predict failure load (Pmax) of high strength concrete (HSC) and ultra high strength concrete (UHSC) beam specimens. Characterization of mix and testing of beams of high strength and ultra strength concrete have been described. Methodologies for evaluation of fracture energy, critical stress intensity factor and critical crack tip opening displacement have been outlined. MARS model has been developed by establishing a relationship between a set of predicators and dependent variables. MARS is based on a divide and conquers strategy partitioning the training data sets into separate regions; each gets its own regression line. Four MARS models have been developed by using MATLAB software for training and prediction of fracture parameters and failure load.MARS has been trained with about 70% of the total 87 data sets and tested with about 30% of the total data sets. It is observed from the studies that the predicted values of Pmax, GF, KIC and CTODC are in good agreement with those of the experimental values.     

基于改进粒子群优化算法的移动机器人路径规划

为了实现微型足球机器人的平滑最优路径规划,提出了一种结合Ferguson样条路径描述和改进粒子群优化算法的路径规划方法。利用Ferguson样条描述移动机器人路径,将路径规划问题转化为三次样条曲线的参数优化问题,借助改进的具有速度变异的粒子群算法进行路径优化。仿真实验表明,算法可以有效进行障碍环境下机器人的无碰撞路径规划,改进的粒子群算法进行路径优化迭代80次左右即可收敛,规划路径平滑、合理,有一定的实用价值。     

Towards automating the discovery of certain innovative design principles through a clustering-based optimization technique

In this article, a methodology is proposed for automatically extracting innovative design principles which make a system or process (subject to conflicting objectives) optimal using its Pareto-optimal dataset. Such ‘higher knowledge’ would not only help designers to execute the system better, but also enable them to predict how changes in one variable would affect other variables if the system has to retain its optimal behaviour. This in turn would help solve other similar systems with different parameter settings easily without the need to perform a fresh optimization task. The proposed methodology uses a clustering-based optimization technique and is capable of discovering hidden functional relationships between the variables, objective and constraint functions and any other function that the designer wishes to include as a ‘basis function’. A number of engineering design problems are considered for which the mathematical structure of these explicit relationships exists and has been revealed by a previous study. A comparison with the multivariate adaptive regression splines (MARS) approach reveals the practicality of the proposed approach due to its ability to find meaningful design principles. The success of this procedure for automated innovization is highly encouraging and indicates its suitability for further development in tackling more complex design scenarios.