基于区域注册机制移动IP系统Dynamics的实现、分析与改进

对HUT Mobile IP系统Dynamics的区域注册机制进行了详细分析,讨论了层次型FA模型中的区域注册机制.详细阐述了区域注册机制的实现过程和区域注册机制的具体设计方法,最后从时延等方面进行分析,给出了进一步的改进措施.分析表明,区域注册机制可以大大降低注册时延、减少注册数据包的数量、改善移动IP的性能,将是未来移动IP实现的主流.     

基于分窗口相关的遥感图象配准方法

多源遥感数据的融合和综合应用必须实行严格的配准,若将通过选取控制点的传统方法,用于成象特性差异较大的图象间配准就存在较大的误差,为解决该问题,研究发展了一种基于分窗口相关的图象配准方法,即采用移动窗灰度相关的方法对图象上的每一点进行搜索,来寻找最大相关位置,以达到精确配准的目的。通过将该方法应用于不同时相的TM图象、SAR图象、不同成象方式和不同分辨率的AVIRIS图象和航片间配准的实验表明,该方法能够有效地实现复杂图象间的精确配准,配准误差已达到子象素级水平。     

补课登记管理系统的设计与实现

软件学院的补课登记是由教务处老师手工完成的,工作量大而繁琐,还容易出现误差。本课题采用B/S模式,实现全院课程调整的管理,包括停课及补课登记等功能,可以较好地解决以上的问题。同时还实现了管理员安排课程等后台功能。本课题使用ASP.NET作为开发技术,利用SQL Server 2000设计后台数据库以及ADO.NET数据库访问技术,实现对数据库的各种管理操作,实现了学院补课登记管理的基本功能。     

基于知识产权保护的软件注册功能设计与实现

由于计算机软件的自身特点及其保护的特殊性,执行起来存在一定的难度,采用恰当的技术手段,针对软件注册的原理和过程进行了研究,收到了良好的保护效果。     

Using retinex for point selection in 3D shape registration

Inspired by retinex theory, we propose a novel method for selecting key points from a depth map of a 3D freeform shape; we also use these key points as a basis for shape registration. To find key points, first, depths are transformed using the Hotelling method and normalized to reduce their dependence on a particular viewpoint. Adaptive smoothing is then applied using weights which decrease with spatial gradient and local inhomogeneity; this preserves local features such as edges and corners while ensuring smoothed depths are not reduced. Key points are those with locally maximal depths, faithfully capturing shape. We show how such key points can be used in an efficient registration process, using two state-of-the-art iterative closest point variants. A comparative study with leading alternatives, using real range images, shows that our approach provides informative, expressive, and repeatable points leading to the most accurate registration results.     

高分辨率影像配准误差对土地覆盖分类和变化检测的影响

近年来高分辨率影像技术发展迅速,土地专题信息的提取对高分辨率数据处理的质量提出了更高的要求,针对配准误差对影像处理和应用的影响研究,有助于专题信息提取过程中遥感数据处理质量控制指标的确定。选取北京市通州区不同时相的IKONOS影像作为实验数据进行模拟研究,在实验研究中通过产生具有不同配准误差的图像,从影像融合、土地覆盖分类和变化检测等角度,分析不同的配准误差对遥感应用的影响。结果表明:随着配准误差的增大,融合图像的可分辨性降低,配准误差增加到3个像元时,土地覆盖分类精度降低2~3%,土地覆盖变化检测中增加了5%的伪变化信息,虚检率增大。     

A low-dimensional representation for robust partial isometric correspondences computation

Intrinsic shape matching has become the standard approach for pose invariant correspondence estimation among deformable shapes. Most existing approaches assume global consistency. While global isometric matching is well understood, only a few heuristic solutions are known for partial matching. Partial matching is particularly important for robustness to topological noise, which is a common problem in real-world scanner data. We introduce a new approach to partial isometric matching based on the observation that isometries are fully determined by local information: a map of a single point and its tangent space fixes an isometry. We develop a new representation for partial isometric maps based on equivalence classes of correspondences between pairs of points and their tangent-spaces. We apply our approach to register partial point clouds and compare it to the state-of-the-art methods, where we obtain significant improvements over global methods for real-world data and stronger guarantees than previous partial matching algorithms.     

Multivariate regression modeling for monitoring quality of injection moulding components using cavity sensor technology: Application to the manufacturing of pharmaceutical device components

There is an increased demand within the moulding industry to improve the quality of moulded parts by maintaining consistent tolerances and overall dimensions. This interest is more important in areas of the moulding industry that are dedicated to pharmaceutical devices, where a quality by design approach is now expected to be adopted. A pharmaceutical device is an assembly of different plastic components which are manufactured by injection moulding; many have critical quality parameters which affect not only the device appearance but also more importantly its performance for drug delivery. Hence, the need of better understanding and control of injection moulding processes. This study presents the use of multivariate regression modeling approach to monitor the quality of the final product using cavity sensor technology (CST). The influence of the injection moulding process parameters on the quality of the final parts have been investigated using a design of experiment approach. The results demonstrate that the Partial Least Squares (PLS) regression model based on cavity pressure sensor data could be successfully used to monitor the quality (weight, dimensions) of the final product in plastic injection moulding.     

Registration and interactive planar segmentation for stereo images of polyhedral scenes

We introduce a two-step iterative segmentation and registration method to find coplanar surfaces among stereo images of a polyhedral environment. The novelties of this paper are: (i) to propose a user-defined initialization easing the image matching and segmentation, (ii) to incorporate color appearance and planar projection information into a Bayesian segmentation scheme, and (iii) to add consistency to the projective transformations related to the polyhedral structure of the scenes. The method utilizes an assisted Bayesian color segmentation scheme. The initial user-assisted segmentation is used to define search regions for planar homography image registration. The two reliable methods cooperate to obtain probabilities for coplanar regions with similar color information that are used to get a new segmentation by means of quadratic Markov measure fields (QMMF). We search for the best regions by iterating both steps: registration and segmentation.     

Scalable Multi‐view Registration for Multi‐Projector Displays on Vertically Extruded Surfaces

Recent work have shown that it is possible to register multiple projectors on non‐planar surfaces using a single uncalibrated camera instead of a calibrated stereo pair when dealing with a special class of non‐planar surfaces, vertically extruded surfaces. However, this requires the camera view to contain the entire display surface. This is often an impossible scenario for large displays, especially common in visualization, edutainment, training and simulation applications. In this paper we present a new method that can achieve an accurate geometric registration even when the field‐of‐view of the uncalibrated camera can cover only a part of the vertically extruded display at a time. We pan and tilt the camera from a single point and employ a multi‐view approach to register the projectors on the display. This allows the method to scale easily both in terms of camera resolution and display size. To the best of our knowledge, our method is the first to achieve a scalable multi‐view geometric registration of large vertically extruded displays with a single uncalibrated camera. This method can also handle a different situation of having multiple similarly oriented cameras in different locations, if the camera focal length is known.