NURBS曲面拟合算法及应用     

丁茹 《天津工程师范学院学报》2004,14(4):30-32

对NURBS(非均匀有理B样条)曲面的拟合算法和利用"权值"局部修改NURBS曲面的方法进行了研究,运用OpenGL技术实现了NURBS曲面的虚拟显示,通过血管的表面重建实验,验证了NURBS曲面拟合算法的正确性。  相似文献   

类钴Nb14+离子3p63d9,3p53d10,3p63d84p组态原子参数的计算     

陈明伦 《贵州教育学院学报》2003,14(2):34-35

用多组态自洽场方法,结合我们提出的半经验拟合公式,计算了高离化态类钴Nb14+离子3p6d9,3p53d10,3p6d84p组态的能级、波长和振子强度,并与实验符合得较好.  相似文献   

改进的FCG软件试验数据处理方法     

WENG Yong-gang 《实验室研究与探索》2007,(10)

应用软件FCG(MTS Fatigue Crack Growth TestW are)采用七点递增多项式局部拟合的方法,计算疲劳裂纹扩展速率da/dN,导致计算值分散度很大。经过详细分析,提出采用正交多项式的线性组合作为疲劳裂纹长度a与载荷循环数N之间关系的拟合目标函数,再用直接求导的方法计算da/dN。这样减小了da/dN的分散度,提高了Paris公式参数拟合和门槛值计算的精度。  相似文献   

Science Letters：Mask synthesis and verification based on geometric model for surface micro-machined MEMS     

李建华刘玉生  高曙明 《浙江大学学报(A卷英文版)》2005,6(9):1007-1010

INTRODUCTION When designers develop microelectromechani- cal system (MEMS) devices with the traditional ap- proach, they should devise the mask-layouts and fabrication process instead of the function and shape of the MEMS device. The geometric model of the MEMS device is then derived based on the simulated fabrication according to the devised mask layout and the process. This is analogous to generating a geo- metric model from the NC tool paths in the macro world. Obviously it is uni…  相似文献   

Multifractal analysis of surface EMG signals for assessing muscle fatigue during static contractions   总被引：1，自引：0，他引：1  

WANG Gang REN Xiao-mei LI Lei WANG Zhi-zhong 《浙江大学学报(A卷英文版)》2007,8(6):910-915

This study is aimed at assessing muscle fatigue during a static contraction using multifractal analysis and found that the surface electromyographic （SEMG） signals characterized multiffactality during a static contraction. By applying the method of direct determination ofthef（a） singularity spectrum, the area of the multifractal spectrum of the SEMG signals was computed. The results showed that the spectrum area significantly increased during muscle fatigue. Therefore the area could be used as an assessor of muscle fatigue. Compared with the median frequency （MDF）--the most popular indicator of muscle fatigue, the spectrum area presented here showed higher sensitivity during a static contraction. So the singularity spectrum area is considered to be a more effective indicator than the MDF for estimating muscle fatigue.  相似文献   

精密过滤曲线的数据拟合技术     

张鸿晨  王磊 《南通职业大学学报》2004,18(2):10-13

本文论述了基于Excel的精密过滤流量曲线整理、数据拟合技术方法。该技术方法在产品开发等工程技术实践中，对具有多参变量的特性曲线整理有指导意义。  相似文献   

Intersections of two offset parametric surfaces based on topology analysis     

欧阳应秀  唐敏  林军呈  董金祥 《浙江大学学报(A卷英文版)》2004,5(3):259-268

Conventional methods for solving intersections between two offset parametric surfaces often include iteratively using computationally expensive SSI (surface/surface intersections) algorithm. In addition, these methods ignore the relations between the intersection curves of parametric surfaces with different offset distances. The algorithm presented in this paper, makes full use of the topological relations between different intersection loops and calculates intersection loops with the help of previously calculated intersection loops. It first pre-processes two parametric surfaces to obtain the characteristic points, called topology transition points (TTPs), which can help in the subsequent finding of the topologies of the intersection curves. Then these points are categorized into several distinct groups, and we can determine the calculation strategy for searching initial points by analyzing the properties of these TTPs on the surfaces. Hence, all intersection curves can be marched from initial points by the tracing algorithm. The proposed algorithm could calculate intersection curves robustly and effectively, and has been tested to be capable of overcoming the degenerate conditions such as loop and singularities leaking that occur frequently in conventional algorithms. Project supported by the National Research Foundation for the Doctoral Program (No. 2000033554) of Higher Education of China and the Natural Science Foundation of Zhejiang Province, China (No. 6001107)  相似文献   

基于最小二乘原理的分段曲线拟合法   总被引：7，自引：0，他引：7  

刘晓莉  陈春梅 《伊犁教育学院学报》2004,17(3):132-134

在最小二乘原理的基础上，运用实测数据点的分段曲线拟合法，探讨相应的模型以及用不同类型的曲线同时拟合数据点的具体应用；对一实例，应用MATLAB编程设计，完成模型的求解、显著性检验等，可以得到拟合精度比较高的拟合曲线。该方法原理简便，其模型易用MATLAB编程求解。  相似文献   

海绵橡皮长时应力松弛试验方法研究     

牛伟  陈勇梅  胡文军  王彤伟 《实验室研究与探索》2007,(11)

通过对海绵橡皮长时应力松弛试验方法的研究,初步确定了适合于海绵橡皮的长时应力松弛试验方法;通过对试验结果进行的曲线拟合,得到了海绵橡皮长时应力松弛性能的数学模型;并采用对比性试验证明了试验方法可适用于海绵橡皮等薄型材料的长时应力松弛试验。  相似文献   

用数码技术研究抛射体的运动规律     

胡昉  毛宏颖  应伟杰  陈守川 《实验技术与管理》2007,24(10):102-104

利用数码相机拍摄小球运动的短片,利用Premiere,Photoshop和Excel等计算机软件合成轨迹图、处理数据和拟合运动曲线,从而探索抛射体的运动规律,并求得重力加速度值。最后分析了表差法处理结果的不确定度。  相似文献