SolidWorks2004新增功能

一、概述 SolidWorks每一个版本都以十几种语言在全球同时进行发布。其中SolidWorks的彻底汉化在很大程度上帮助中国用户快速掌握三维建模技能,并方便地生成满足生产需求的G B标准工程图。SolidWorks每一个版本的升级都有三个重要的体现:来自客户的需求、让已有的功能更加强大和易用、主动为用户提供创新的三维设计技术。SolidWorks2004无疑是SolidWorks目前最为优秀的版本。SolidWorks2004 Office Professional比上一个版本新增了250多项功能,其中核心建模技术超过200项。鉴于其新增功能不胜枚举,本文仅就其中一     

SolidWorks汽车壳体建模初探

在SolidWorks中利用三视图进行汽车建模的一般方法是:首先将汽车视图分别导入到相应基准面作为草绘的参考,然后找到各视图中对应的轮廓线,进行投影形成空间曲线,最后进行放样等操作.限于篇幅,本文将以audi R8为例介绍汽车壳体建模的大致过程,细节部分省略,留给读者们自行完善.     

领略三维设计的主流风彩——例说实体建模软件SolidWorks2001

现代三维设计软件不仅能够创建包含丰富的实体信息的三维实体模型，还能利用其设计阶段产生的各种基于特征的参数对实体模型进行静态或动态的干涉检查、模拟装配、动力学和机构运动学分析、强度分析、设计模具、数控制造、美工处理等，这些是业界长期追求的目标，现在实际上也成为工程师判断一款三维设计软件的默认标准，SolidWorks２００１是新一代的三维设计业界主流软件。它在PC机Windows平台下就可以进行高质量的三维建模，尤其对复杂的三维模型（模型中各个部分有复杂的拓扑关系及高度复杂的多元函数依赖关系）更显其强大的功能，但…     

SolidWorks与CAXAWEDM相结合模拟加工精密凸轮

这是一篇有关凸轮线切割加工技巧的小文章。虽然没有什么高深的理论。但文章结构完整，实用性很好。对类似工件的线切割加工有一定的参考价值。     

基于VB的SolidWorks远程建模的研究

对CAD软件的二次开发可以大大提高软件使用效率,实现特定功能。基于Visual Basic 6.0开发的SolidWorks远程绘图功能,解决了本地机器在没有安装CAD软件下进行三维建模的难题。     

端面圆柱凸轮的数控加工

端面圆柱凸轮是一种特殊的圆柱凸轮,在机械设备中得到了广泛的应用。圆柱凸轮的加工一般在带有回转轴的四轴数控铣床进行,但也可采用三坐标数控铣床进行加工。该文就介绍了综合使用Pro/ENGINEER软件和MasterCAM软件,在三坐标数控铣床上完成端面圆柱凸轮三维建模和数控加工编程的一般过程和基本方法。     

坐标绘图法在AutoCAD三维建模中的应用

AutoCAD三维建模中经常会遇到空间位置不同的点呈现出重合的位置关系,在这种情况下直接利用AutoCAD软件系统所提供的精确绘图辅助工具和命令,诸如对象捕捉等来拾取点对象时,很有可能会出现误操作。而运用坐标绘图法能够精确到空间中的任意一个点位置,避免在遇到重合位置点时错误捕捉拾取对象的情况。本文采用实例讲解了在AutoCAD三维建模中运用坐标绘图法的优势、技巧及注意事项等方面的问题。     

完成端口模型的使用与分析

完成端口是一种复杂的Win32内核对象。应用程序可以用完成端口管理线程池为大量的异步I/O请求提供服务,而不必为每个I/O请求分别创建服务线程。完成端口模型用于开发服务器应用程序,以提供优良的伸缩性和获得最好的系统性能。本文构建了一个基本的网络服务器程序框架,对完成端口模型的用法进行阐述与分析。     

A Computational Model for Amodal Completion

This paper presents a computational model to recover the most likely interpretation of the 3D scene structure from a planar image, where some objects may occlude others. The estimated scene interpretation is obtained by integrating some global and local cues and provides both the complete disoccluded objects that form the scene and their ordering according to depth. Our method first computes several distal scenes which are compatible with the proximal planar image. To compute these different hypothesized scenes, we propose a perceptually inspired object disocclusion method, which works by minimizing the Euler’s elastica as well as by incorporating the relatability of partially occluded contours and the convexity of the disoccluded objects. Then, to estimate the preferred scene, we rely on a Bayesian model and define probabilities taking into account the global complexity of the objects in the hypothesized scenes as well as the effort of bringing these objects in their relative position in the planar image, which is also measured by an Euler’s elastica-based quantity. The model is illustrated with numerical experiments on, both, synthetic and real images showing the ability of our model to reconstruct the occluded objects and the preferred perceptual order among them. We also present results on images of the Berkeley dataset with provided figure-ground ground-truth labeling.     

完工满意度最大的伙伴挑选模型

针对动态联盟企业项目完工风险问题,基于模糊计划评审法（F-PERT）描述项目的运行,建立了相应的非线性整数规划模型,并设计了嵌入F—PERT的遗传算法进行求解．实例研究表明,该方法在运行时间和效果方面是有效的,从而为模糊情况下的伙伴挑选问题提供了一种有效的管理工具．     

基于加权核范数最小化的矩阵填充模型

协同过滤是目前推荐系统最常用的技术之一,相比于传统的推荐技术具有一定优势,但其缺点是受用户对商品评价的稀疏性制约,现阶段一般利用矩阵填充技术来解决这一问题。主要研究了基于低秩的矩阵填充模型,针对原有模型解对所有奇异值用同一值收缩的问题,提出了一种加权核范数最小化模型以提高核范数灵活度,给出了该模型用收缩算子可得到全局最优解的相关定理及证明,同时对模型的另一种形式在求解过程中的迭代收敛性进行了证明。用凸优化主流算法在两种真实数据集上进行的实验表明,改进后的模型一定程度上提高了计算速度与准确性。     

四元数关系旋转的知识图谱补全模型

知识图谱是真实世界三元组的结构化表示,通常三元组被表示成头实体、关系、尾实体的形式.针对知识图谱中广泛存在的数据稀疏问题,提出了一种将四元数作为关系旋转的知识图谱补全方法.文中使用极具表现力的超复数表示对实体和关系进行建模,以进行链接预测.这种超复数嵌入用于表示实体,关系则被建模为四元数空间中的旋转.具体来说,将每个关...     

基于四元数胶囊网络的知识图谱补全模型

知识图谱采用RDF三元组的形式描述现实世界中的关系和头、尾实体,即（头实体,关系,尾实体）或（主语,谓语,宾语）。为补全知识图谱中缺失的事实三元组,将四元数融入胶囊神经网络模型预测缺失的知识,并构建一种新的知识图谱补全模型。采用超复数嵌入取代传统的实值嵌入来编码三元组结构信息,以尽可能全面捕获三元组全局特性,将实体、关系的四元数嵌入作为胶囊网络的输入,四元数结合优化的胶囊网络模型可以有效补全知识图谱中丢失的三元组,提高预测精度。链接预测实验结果表明,与CapsE模型相比,在数据集WN18RR中,该知识图谱补全模型的Hit@10与正确实体的倒数平均排名分别提高3.2个百分点和5.5%,在数据集FB15K-237中,Hit@10与正确实体的倒数平均排名分别提高2.5个百分点和4.4%,能够有效预测知识图谱中缺失的事实三元组。     

Subjective Surfaces: A Geometric Model for Boundary Completion

We present a geometric model and a computational method for segmentation of images with missing boundaries. In many situations, the human visual system fills in missing gaps in edges and boundaries, building and completing information that is not present. Boundary completion presents a considerable challenge in computer vision, since most algorithms attempt to exploit existing data. A large body of work concerns completion models, which postulate how to construct missing data; these models are often trained and specific to particular images. In this paper, we take the following, alternative perspective: we consider a given reference point within the image, and then develop an algorithm which tries to build missing information on the basis of the given point of view and the available information as boundary data to the algorithm. Starting from this point of view, a surface is constructed. It is then evolved with the mean curvature flow in the metric induced by the image until a piecewise constant solution is reached. We test the computational model on modal completion, amodal completion, and texture segmentation. We extend the geometric model and the algorithm to 3D in order to extract shapes from low signal/noise ratio ultrasound image volumes. Results in 3D echocardiography and 3D fetal echography are also presented.     

利用矩阵补全优化模型进行动态网络链接预测

动态链接预测是网络数据挖掘领域的一个重要课题,主要原理是根据以往的网络结构预测未来的网络结构状态。目前,静态链接预测已得到充分研究,但对动态链接预测的研究却比较稀少。根据网络链接的结构特点,将矩阵补全方法引入动态链接预测问题中,进一步受核矩阵分解的启发,建立了核矩阵补全模型,将数据映射到高维空间中,使得链接中的非线性关系转化为线性关系,从而使得模型能够处理更复杂的网络结构。通过在三个公开网络数据集上进行实验,验证了矩阵补全优化方法和核方法在动态链接预测中的有效性和准确性。     

A Cortical Based Model of Perceptual Completion in the Roto-Translation Space

We present a mathematical model of perceptual completion and formation of subjective surfaces, which is at the same time inspired by the architecture of the visual cortex, and is the lifting in the 3-dimensional rototranslation group of the phenomenological variational models based on elastica functional. The initial image is lifted by the simple cells to a surface in the rototranslation group and the completion process is modeled via a diffusion driven motion by curvature. The convergence of the motion to a minimal surface is proved. Results are presented both for modal and amodal completion in classic Kanizsa images. The work was supported by University of Bologna: founds for selected research topics. Giovanna Citti is full professor of Mathematical Analysis at University of Bologna, and she is coordinator, together with A.Sarti, of the local interdipartimental group of “Neuromathematics and Visual Cognition”. Her principal research interests are existence and regularity of solution of nonlinear subelliptic equations represented as sum of squares of vector fields, whose associated geometry is subriemannian. Besides she is interested in applications of instruments of real analysis in Lie Groups and subriemannian geometry to visual perception, and to the study of the functionality of the visual cortex. Alessandro Sarti received the Ph.D. degree in bioengineering from the University of Bologna in 1996. From 1997 to 2000 he was appointed with a Postdoc position at the Mathematics Department of the University of California, Berkeley, and the Mathematics Department of the Lawrence Berkeley National Laboratory in Berkeley. Since 2001 he got a permanent position at the University of Bologna. He is associate to CREA, Ecole Polytechnique, Paris, France. With Giovanna Citti, he is the scientific responsible of the interdipartimental group of “Neuromathematics and Visual Cognition.” In the last years he gave lectures at the University of Yale, University of California at Los Angeles, University of California at Berkeley, Freie Universitat Berlin, Ecole Normale Superieure Cachan, Ecole Polytechnique, Scuola Normale Superiore di Pisa.