一种NURBS曲面拟合精度的量化评测算法

曲面重构是逆向工程中的核心技术之一,由于NURBS曲面在光顺性和局部可编辑等方面所具有的优点,使其成为点云数据自由曲面重构的常见形式。目前对NURBS曲面重构技术的研究上取得了一些成果,但各方法在拟合精度和效果上各有参差,因此有必要对NURBS曲面拟合精度评价算法进行研究。在采用NURBS实现曲面拟合的基础上,对拟合精度的量化指标进行研究,设计了一种基于区域划分的搜索迭代算法,可快速地计算得到原始点云与NURBS曲面的偏差。     

Uniqueness of the Perfect Fusion Grid on ℤ d

Region merging methods consist of improving an initial segmentation by merging some pairs of neighboring regions. In a graph, merging two regions, separated by a set of vertices, is not straightforward. The perfect fusion graphs defined in J. Cousty et al. (J. Math. Imaging Vis. 30:(1):87–104, 2008) verify all the basic properties required by region merging algorithms as used in image segmentation. Unfortunately, the graphs which are the most frequently used in image analysis (namely, those induced by the direct and the indirect adjacency relations) are not perfect fusion graphs. The perfect fusion grid, introduced in the above mentioned reference, is an adjacency relation on ℤ ^d which can be used in image analysis, which indeed induces perfect fusion graphs and which is “between” the graphs induced by the direct and the indirect adjacencies. One of the main results of this paper is that the perfect fusion grid is the only such graph whatever the dimension d.

基于感兴趣区梯度方向直方图的行人检测

针对以梯度方向直方图作为人体特征的行人检测存在向量维数较大、检测时间较长的问题,提出基于感兴趣区梯度方向直方图的行人检测方法,分别在头部及四肢等重点区域计算梯度方向直方图,有效地减少了向量维数。实验结果表明,该方法在检测率基本不变的情况下提高了检测速度。     

一种基于受限约束范围标签传播的半监督学习算法

提出一种基于受限约束范围标签传播的半监督学习算法。首先利用相似性矩阵计算得出概率转移矩阵,进而通过概率转移矩阵得出受限约束范围。然后在约束范围内利用半监督学习框架下的标签传播算法计算基于路径的相似性,路径相似性决定了标签传播的重要路径。由于只使用几条重要的传播路径使得算法中省去计算每一条路径的相似度,计算复杂度大大减少。最终使得标签在带标签数据与未标签数据之间通过几条重要的路径之间传播。实验已经证明此算法的有效性。     

二值图像中标定目标区域的几何特征提取

本文论述了采用标答处理对二值图像中感兴趣目标区域的标定方法,给出了几种常用几何形状特征的提取方法,提出了一种通用性较强、便于提高取被选定目标区域的外边界轮廓和几何形状特征的边界跟踪算法。实验表明,该算法对含有洞的区域也是行之有效的。     

Identification and sizing of the entirely visible rocks from a 3D surface data segmentation of laboratory rock piles

Once segmentation of 3D surface data of a rock pile has been performed, the next task is to determine the visibility of the surface rocks. A region boundary-following algorithm that accommodates irregularly spaced 3D coordinate data is presented for determining this visibility. We examine 3D surface segmentations of laboratory rock piles and determine which regions in the segmentation correspond to entirely visible rocks, and which correspond to overlapped or partially visible rocks. This is a significant distinction as it allows accurate size determination of entirely visible rocks, separate handling of partially visible rocks, and prevents erroneous bias resulting from mishandling partially visible rocks as smaller entirely visible rocks. Literature review indicates that other rock pile sizing techniques fail to make this distinction. The rock visibility results are quantified by comparison to manual surface classifications of the laboratory piles and the size results are quantified by comparison to the sieve size.     

宁夏遥感影像旅游地图的编制

为更加充分地展示宁夏地貌、地形特点,选用平面制图软件CorelDRAW12,从宁夏遥感影像地图的整体设计、特色符号设计、绘制地图等方面制作宁夏遥感影像旅游地图,使其成为独具宁夏文化旅游特色的旅游地图,并把宁夏旅游信息传递给各地游客．     

中部地区清洁发展机制（CDM）项目发展状况与问题分析

清洁发展机制是《京都议定书》创建的三种灵活机制之一,其目标是可持续发展与环境完整性。我国政府十分重视清洁发展机制的运用与发展。文章从通过国家发改委审批、执行理事会（EB）注册和GER签发三个阶段数据,对中部地区目前CDM项目发展现状及存在问题进行剖析,并提出发展建议。     

丝绸之路与汉代西域的毛纺织技术

以新疆洛浦县山普拉出土的汉代毛纺织物为研究样本,通过对服装、装饰带、缀织绦、毛毯等出土文物的分析,指出:丝绸之路的开通使得希腊艺术、中原艺术、草原游牧民族艺术与本土艺术得到了前所未有的交融和并行的发展,汉代西域毛纺织技术展示了汉代时期西域地区民族文化的一个侧面,它是丝绸之路上中外纺织技术交流发展的结果.