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1.
提出的算法是先以快速的方法判断线与多边形是否有交点,如有,则求出线与多边形的各个交点,将交点进行排序,将此线按交点顺序分为多段;如果无交点,则此线只有一段。检测各段中点是否位于多边形内,如果位于内部,则此段在内,否则此段在外。以倾斜射线法检测点的包容性,其特点是此射线不与多边形的顶点或边重合,无须作特殊情况的处理,计算区域小,因而计算量小,对自相交多边形及带孔多边形等多类情况同样适用。通过编写程序计算验证表明,此算法简单有效、稳定可靠,适用于多类情况。  相似文献   

2.
基于支持向量机的手写体数字识别系统设计   总被引:6,自引:2,他引:4  
蒙庚祥  方景龙 《计算机工程与设计》2005,26(6):1592-1594,1598
数字识别是光学字符识别技术里发展比较早的一种技术,是OCR的一个分支。数字识别又分为手写数字识别和非手写数字识别,提到的手写数字识别是指脱机手写数字识别。支持向量机是近几年来模式识别领域中的一个新技术,它被广泛应用到文字识别、人脸识别等应用中,是模式识别领域中的研究热点,把支持向量机技术应用到手写数字识别系统中,以期提高识别系统的性能。  相似文献   

3.
本文阐述NDJCMT系统中词的自动切分技术, NDJCMT是我们实现的一个日汉机器翻译实验系统, 词的自动切分是日语词素分析、句法及语义分析的基础, 是一项日本语计算机信息处理的基础性研完课题, 它涉及对语言本身的研究。日语和汉语类似, 词及词之间无分隔符, 通常假名、汉字混写, 给词的切分造成了困难。作者根据日语的特点, 提出了一种“ 句节数最少” 词的自动切分方法, 使用语言编程且在一机上获得实现。  相似文献   

4.
The problem of robust stability and convergence of learning parameters of adaptation algorithms in a noisy environment for the single preceptron is addressed. The case in which the same input pattern is presented in the adaptation cycle is analyzed. The algorithm proposed is of the Widrow-Hoff type. It is concluded that this algorithm is robust. However, the weight vectors do not necessarily converge in the presence of measurement noise. A modified version of this algorithm in which the reduction factors are allowed to vary with time is proposed, and it is shown that this algorithm is robust and that the weight vectors converge in the presence of bounded noise. Only deterministic-type arguments are used in the analysis. An ultimate bound on the error in terms of a convex combination of the initial error and the bound on the noise is obtained.  相似文献   

5.
为实现白车身轻量化,以白车身零件厚度为优化变量,建立参数化模型。定义白车身静态扭转刚度工况并进行有限元分析,得到扭转刚度响应和轻量化系数,采用解析法推导轻量化系数对厚度的灵敏度。基于HyperMesh二次开发完成灵敏度分析流程自动化,求解白车身轻量化系数的灵敏度。根据灵敏度排序对白车身零件厚度进行优化,实现轻量化系数降低,扭转刚度提高,白车身质量减轻。  相似文献   

6.
The problem of the existence of redundancy in the data in a recursive estimation problem is investigated. Given a certain data rate, should the estimator be run at the same rate? It is shown that under certain conditions there is redundancy in the data and the estimator can be run at a lower rate using compressed data with practically the same performance as when no data compression is utilized. It is also pointed out that, although at the higher rate there is redundancy in the data, the performance deteriorates noticeably when the data rate is lowered. Conditions for the existence of redundancy in the data and the procedure to remove it are presented. The procedure to compress the data is obtained such as to preserve the information in the sense of Fisher. The effect of data compression is a reduction in the computation requirements by a factor equal to the compression ratio. Such a reduction might be important in real-time applications in which the computing power is limited or too expensive. The application of this technique to the tracking of a reentry vehicle with a linearized filter is discussed in more detail and simulation results are presented.  相似文献   

7.
SOC软硬件划分系统中的关键算法   总被引:1,自引:0,他引:1  
设计并实现了SOC软硬件划分系统,搭建了软硬件协同设计的平台并描述了软硬件协同设计的流程。运用多目标遗传算法对目标系统的价格、功耗、速度进行优化,采用了基于Pareto支配的适应值赋值、精英保持和密度计算截断操作的方法进行多目标寻优。针对单任务图描述多CPU系统结构的不足,提出采用多任务图来描述的方法,并提出了MTLS性能评估算法,验证系统软硬件划分的优劣。在对比实验中将NSGA2算法运用到本系统中,结果证明论文的多目标寻优算法获得的非支配解80%比NSGA2的非支配解优。  相似文献   

8.
用声学、流体力学理论,结合振动学的理论分析声敏感结构的阻尼特性,找出设计应遵循的一些基本原则。通过声学分析,得出了系统的阻尼与质量振动体的质点振速、阻尼介质参数、质量块的表面积和振动频率有关。对于相同的质量块结构,由于表面积相同,则在空气中的声辐射阻小于在液体中的辐射阻,可以得出质量块在空气中的阻尼系数小于在液体中的阻尼系数的结论,并有声系统中辐射阻的作用与拾振系统中阻尼的作用可以等效的结论。对于一维平动、一维非平动、二维有限平板情况,阻尼系数的表达式具有基本相同的形式,阻尼系数与结构参数有关,与板间距h三次方成反比,与材料的粘滞系数成正比。  相似文献   

9.
一类时滞线性系统的变结构控制   总被引:11,自引:2,他引:9  
郑锋  程勉  高为炳 《自动化学报》1995,21(2):221-226
研究一类状态变量具有时滞的线性系统的变结构控制问题,指出传统的切换函数在时滞 系统中应当是一个切换泛函,给出了在系统谱能控条件下具有稳定滑动模态的切换泛函的设 计方法.并利用趋近律设计了相应的变结构控制器.得到了一般时滞系统能够变换为所需要 的时滞系统的条件.  相似文献   

10.
利用时间连续的混沌系统进行保密通信时,停产中传输的是宽带的混沌信号,由于实际的停产总是带限的,这就大在的限制了混沌在通信中的应用。一种改进的方法是在发射端用波波器滤去混沌信号的高频部分,只传输低频部分。而在接收产端用本地产生的混汪信号的高频部分来补偿接收到的信号作为接收端混沌系统的驱动信号。文中提出的方法是在发射端对要发射的混沌信号进行采样,只传输这些时间离散的采样值。在接收端则用本地产生的采样时  相似文献   

11.
Partial shape recognition: a landmark-based approach   总被引:7,自引:0,他引:7  
A method of recognizing partially occluded objects is presented in which each object is represented by a set of landmarks. Given a scene consisting of partially occluded objects, a model object in the scene is hypothesized by matching the landmarks of the model with those in the scene. A measure of similarity between two landmarks is needed to perform this matching. A local shape measure, sphericity, is introduced. It is shown that any invariant function under a similarity transformation is a function of the sphericity. To match landmarks between the model and the scene, a table of compatibility is constructed. A technique, known as hopping dynamic programming, is described to guide the landmark matching through the compatibility table. The location of the model in the scene is estimated with a least-squares fit among the matched landmarks. A heuristic measure is then computed to decide if the model is in the scene  相似文献   

12.
浮点数编码具有精度高、便于高维大空间搜索的优点,在函数优化和约束优化领域明显有效于其他编码。浮点数编码遗传算法在操作环境中产生的噪音和对算法性能的影响尚不被人们所认识。将小波用于浮点数编码遗传算法的消噪变异是解决该问题的有效途径。单一小波对浮点数编码消噪变异泛化能力低,且对浮点数编码遗传算法性能改进有一定的局限性。研究证明了用酉变换可构造正交多小波,将正交多小波用于浮点数编码遗传算法的消噪变异,提出了FGAMW方法,并进行了实验。理论研究和实验结果表明,提出的FGAMW方法理论上是可靠的,技术上是可行的,对于拓展浮点数编码遗传算法的应用空间具有积极的意义。  相似文献   

13.
MCS-51和MSP430单片机定时器的应用比较   总被引:1,自引:0,他引:1  
吴怀超 《工业控制计算机》2010,23(9):99-100,102
以单片机产生PWM波作为实例,对MCS-51单片机定时器T0和MSP430单片机的TimerA进行了比较,得知MCS-51单片机定时器T0结构简单、入门容易、使用方便,但功能较弱,对编程技巧要求较高,而MSP430单片机的TimerA结构复杂、功能强大、入门不易,但使用灵活,对编程技巧要求不高,从而建议用户应根据自身的知识基础和应用场合来选择单片机实现定时的功能。  相似文献   

14.
利用SOM网络模型进行聚类研究   总被引:2,自引:0,他引:2  
自组织特征映射(SOM)是Kohonen提出的一种人工神经网络模型,其整个学习过程是在输入样本空间内进行.并以欧氏距离为度量。本文先介绍了SOM网络模型的来源,接着对SOM网络的结构与学习过程进行了介绍,最后给出了一个SOM网络模型在聚类中的程序实例。  相似文献   

15.
移动立方体是面绘制的经典算法,但要求对所有空间所有体素进行处理,执行效率不高.通过对空间相关性进行研究,即六面体体素如果与等值面相交,则等值面一定会在该六面体的6个面的方面延续,对标准的MC算法进行改进,只处理那些与等值面相交的六面体体素.可视化工具包封装了许多常用的可视化算法,为研究人员提供了极大的便利.通过空间相关性,对VTK中已有库函数vtkMarchingCubes进行改进,提高了原有算法的执行速度,同时又扩充了VTK已有的类.  相似文献   

16.
解鹏  崔刚  伍文冰  杨孝宗 《计算机学报》1999,22(10):1085-1089
首先分析了FFT阵一中蝶形单元的故障模式,提出了一致故障的概念,并根据傅立叶变换的性能,提出一个新的故障检测机制:卷积检测,并证明了该机制对单输出端故障和一致性瓣覆盖为100%。  相似文献   

17.
Embedding a number of displacement features into a base surface is common in industrial product design and modeling, where displaced surface regions are blended with the unmodified surface region. The cubic Hermite interpolant is usually adopted for surface blending, in which tangent plane smoothness across the boundary curve is achieved. However, the polynomial degree of the tangent field curve obtained symbolically is considerably higher, and the reduction of the degree of a freeform curve is a non-trivial task. In this work, an approximation surface blending approach is proposed to achieve tangential continuity across the boundary curve. The boundary curve is first offset in the tangent field with the user-specified tolerance, after which it is refined to be compatible with the offset curve for surface blending. Since the boundary curve is offset in a three-dimensional (3D) space, the local self-intersection in the offset curve is addressed in a 2D space by approximately mapping the offset vectors in the respective tangent planes to the parameter space of the base surface. The proposed algorithm is validated using examples, and the normal vector deviation along the boundary curve is investigated.  相似文献   

18.
服务质量QoS管理是满足分布式环境中端到端QoS需求的关键,而中间件是一种分布式系统中的主要交互平台.首先对中间件和QoS的相关概念进行介绍,在分析传统QoS管理模型的基础上,提出一种基于消息中间件(MOM)的QoS管理模型,重点分析多维QoS在该模型中的应用,最后结合一个实例说明多维QoS在实际系统中的应用.  相似文献   

19.
面向客户需求ERP产品可重构开发模型研究   总被引:4,自引:0,他引:4  
目前ERP系统在开发中主要存在两个问题:一是ERP产品在开发的过程中存在大量的重复工作,系统的开发周期比较长;二是ERP产品的刚性太强,系统的柔性差,适应性不强。针对上述问题,文章提出了客户需求驱动,可重构ERP软件开发模型,阐述了基于客户需求分析的动态企业建模、可重构ERP软件开发的主要技术和系统构建方法。  相似文献   

20.
Edge location to subpixel values in digital imagery   总被引:27,自引:0,他引:27  
A new method for locating edges in digital data to subpixel values and which is invariant to additive and multiplicative changes in the data is presented. For one-dimensional edge patterns an ideal edge is fit to the data by matching moments. It is shown that the edge location is related to the so-called ``Christoffel numbers.' Also presented is the study of the effect of additive noise on edge location. The method is extended to include two-dimensional edge patterns where a line equation is derived to locate an edge. This in turn is compared with the standard Hueckel edge operator. An application of the new edge operator as an edge detector is also provided and is compared with Sobel and Hueckel edge detectors in presence and absence of noise.  相似文献   

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