On fuzzy sobriety

This paper mainly shows that sober fuzzy topological spaces form the epireflective hull of the fuzzy Sierpinski space in the category of T₀-fuzzy topological spaces.     

Preserving Topology by a Digitization Process

The main task of digital image processing is to recognize properties of real objects based on their digital images. These images are obtained by some sampling device, like a CCD camera, and represented as finite sets of points that are assigned some value in a gray-level or color scale. Based on technical properties of sampling devices, these points are usually assumed to form a square grid and are modeled as finite subsets of Z². Therefore, a fundamental question in digital image processing is which features in the digital image correspond, under certain conditions, to properties of the underlying objects. In practical applications this question is mostly answered by visually judging the obtained digital images. In this paper we present a comprehensive answer to this question with respect to topological properties. In particular, we derive conditions relating properties of real objects to the grid size of the sampling device which guarantee that a real object and its digital image are topologically equivalent. These conditions also imply that two digital images of a given object are topologically equivalent. This means, for example, that shifting or rotating an object or the camera cannot lead to topologically different images, i.e., topological properties of obtained digital images are invariant under shifting and rotation.     

面向与历史无关造型的三维约束求解方法研究

以基于历史的造型系统中应用较为成熟的两项技术——特征编码和二维约束求解为基础，基于特征进行三维约束建模，从而打破传统的基于历史造型系统中特征之间的单向依赖关系；然后将三维约束关系映射到二维草图进行处理，简化了问题．该方法在InteSolid 2．0上实现．     

一种可视外壳的快速拓扑生成算法

针对各种传统可视外壳生成算法中数据冗余及壮健性不足等问题，提出了一种新的从阴影图像中快速重构物体可视外壳的壮健的算法，即首先利用物体表面的拓扑结构直接生成外壳，然后使用改进的SurfaceNet算法光滑三维表面，从而在保留经典的体求交方法壮健性的基础上，克服了对于物体内部点的冗余计算和存储问题，不仅使得计算的时间复杂度降低到仅线性依赖于外壳上结点的数目，而且降低了像片数对算法复杂度产生的影响，实验结果表明，在算法复杂度和壮健性上优于诸如八叉树等传统可视外壳算法。     

Mappings of Figure Spaces and Systems of These Spaces

The formation of an informal theory of figure spaces is considered. In particular, interesting and natural generalizations of such fundamental mathematical concepts as continuous and uniformly continuous mappings are proposed.     

Research on Constructing Contours from Regular Terrain Grids Containing Invalid Data

A new method for constructing contours from complicated terrain elevation grids containing invalid data is put forward. By using this method, the topological consistency of contours in groups can be maintained effectively and the contours can be drawn smoothly based on boundaries pre-searching and local correction. An experimental example is given to demonstrate that the contours constructed by this method are of good quality.     

基于遗传算法的网格结构的拓扑优化

遗传算法是一种新兴的基于遗传进化机理的寻优技术。它与常规算法的不同之处在于不受初始值影响、从多个初始点开始寻优，并采用交叉、变异和移民算子避免过早地收敛到局部最优解，可获得全局最优解。该算法不必求导计算，编程简单、快捷，尤其适用于具有离散变量的结构优化设计。本文利用遗传算法对在应力、位移约束下的网格结构进行拓扑优化，利用对称性对杆件进行分组，使优化后的结构模型仍然保持对称，具有工程应用价值，并达到降低造价的目的。计算实例表明了该算法的有效性。     

浅析防火墙技术

随着计算机网络系统的迅速发展和广泛应用,网络及信息安全的问题越来越受到人们的高度重视.探讨了防火墙系统的结构以及防火墙系统功能、拓扑结构的选择.     

序列模式挖掘在网络告警分析中的应用

序列模式挖掘可以用来有效地发现网络系统中的告警关联知识.论文研究了序列模式挖掘在网络告警分析中的具体应用.首先,将挖掘过程分成了特定设备告警序列挖掘、同类设备告警序列挖掘和互联设备告警序列挖掘等3类,根据不同的用户意图来有效地确定挖掘范围,避免对无关数据的访问.为了进一步提高挖掘算法的执行效率,又提出了用于描述网络拓扑信息的拓扑约束,并设计了基于拓扑约束的互联设备告警序列模式挖掘算法.     

空间对象及其拓扑关系

论文首先讨论了传统的地理信息系统中空间对象的空间数据模型,提出了面向对象的层次矢量数据模型。然后定性地分析了空间对象点与点、点与线和点与区域之间的拓扑关系,并给出了一种形式化表达空间对象成分拓扑关系的模型。最后,将这种模型与空间对象之间的拓扑关系结合起来,使其可以方便地处理地理信息系统中的对象间的拓扑关系。