Application of the active shape model in a commercial medical device for bone densitometry

Osteoporosis is a common disorder characterised mainly by low bone mineral density (BMD), and leading to an increased risk of fracture. We have developed a new device that estimates BMD from ordinary hand radiographs. A crucial element of this method is the reconstruction of the metacarpals. This paper describes how this was solved using the active shape model (ASM). Standard ASM is unable to locate the metacarpal shafts in the direction along the bones. Therefore ASM was extended with a translation operator, which solved the problem. A hierarchical filtering method was used to construct a sufficient list of initial guesses for the ASM. The performance of ASM and the experience with the integration of ASM in a commercial medical device is reported. The ASM achieves 99.5% reconstruction success and is able to validate its own reconstruction in 97% of the cases. The system (Pronosco X-posure system, version 2.0) has been approved by the FDA, and more than 100 units have been sold.The concept of the translation operator is generalised to the more active shape model (MASM), which also allows a natural integration with the active appearance model.     

基于ECA 规则的仿真系统研究设计

分析冷连轧仿真系统的主动性需求，结合数据库在仿真系统中的作用，提出基于主动数据库的仿真系统设计。对主动规则的原理和执行进行分析，给出了基于主动规则——ECA规则的仿真系统的设计和运行机制，用ECA规则描述应用系统执行操作和事件处理，完成系统的主动性行为。并以冷连轧仿真系统中物料跟踪在一机架前的事件动作为例，运用ECA规则进行设计。     

3-D shape reconstruction in an active stereo vision system using genetic algorithms

The recovery of 3-D shape information (depth) using stereo vision analysis is one of the major areas in computer vision and has given rise to a great deal of literature in the recent past. The widely known stereo vision methods are the passive stereo vision approaches that use two cameras. Obtaining 3-D information involves the identification of the corresponding 2-D points between left and right images. Most existing methods tackle this matching task from singular points, i.e. finding points in both image planes with more or less the same neighborhood characteristics. One key problem we have to solve is that we are on the first instance unable to know a priori whether a point in the first image has a correspondence or not due to surface occlusion or simply because it has been projected out of the scope of the second camera. This makes the matching process very difficult and imposes a need of an a posteriori stage to remove false matching.In this paper we are concerned with the active stereo vision systems which offer an alternative to the passive stereo vision systems. In our system, a light projector that illuminates objects to be analyzed by a pyramid-shaped laser beam replaces one of the two cameras. The projections of laser rays on the objects are detected as spots in the image. In this particular case, only one image needs to be treated, and the stereo matching problem boils down to associating the laser rays and their corresponding real spots in the 2-D image. We have expressed this problem as a minimization of a global function that we propose to perform using Genetic Algorithms (GAs). We have implemented two different algorithms: in the first, GAs are performed after a deterministic search. In the second, data is partitioned into clusters and GAs are independently applied in each cluster. In our second contribution in this paper, we have described an efficient system calibration method. Experimental results are presented to illustrate the feasibility of our approach. The proposed method yields high accuracy 3-D reconstruction even for complex objects. We conclude that GAs can effectively be applied to this matching problem.     

主动式网络安全防御系统模型设计

依据动态信息安全模型P~2DR并结合现有的网络安全技术,作者提出了一个主动式的网络安全防御系统模型。本文介绍了模型的体系结构和信息处理流程,最后给出了模型的特点。     

主动网络管理分层设计模式的探讨

通过对主动网络及主动网络管理体系结构的分析,探讨了一种主动网络管理的分层设计模式,对其中每一层的功能、设计要点及其相互关系进行了讨论,说明了基于此模式的主动网络管理软件能够很好地适应主动网络的特点及主动网络管理的需求。     

Non-fragile output feedback H∞ vehicle suspension control using genetic algorithm

This paper presents an approach to design static output feedback and non-fragile static output feedback H_∞ controllers for active vehicle suspensions by using linear matrix inequalities and genetic algorithms. A quarter-car model with active suspension system is considered in this paper. By suitably formulating the minimization problem of the sprung mass acceleration, suspension deflection and tyre deflection, a static output feedback H_∞ controller and a non-fragile static output feedback H_∞ controller are obtained. The controller gain is naturally constrained in the design process. The approach is validated by numerical simulation which shows that the designed static output feedback H_∞ controller can achieve good active suspension performance in spite of its simplicity, and the non-fragile static output feedback H_∞ controller has significantly improved the non-fragility characteristics over controller gain variations.     

MATLAB应用于并联有源混合型滤波器的仿真

比较了无源滤波器和有源滤波器各自优缺点，通过无源滤波器和有源滤波器的混合使用，来克服各自的缺点，达到更精确的补偿谐波效果，且减少了有源滤波器功率要求，降低了成本。该文给出了电路的仿真模型，并使用Matlab对该模型进行仿真，最后得到的仿真结果同理论分析一致，取得满意效果。     

Active X技术用于开发流媒体Web页

介绍了Active X技术,探讨了在C++环境下创建Active X控件的方法,并以播放流媒体WindowsMedia Video为例说明了在Web中的应用。在教育部资助的网络多媒体项目开发过程中使用了多媒体Active X控件,使Internet应用程序更具有诱人的多媒体功能。     

VB与Simulink混合编程

介绍了在 VB6 .0中利用 Active X自动化技术和 M文件来运行 Simulink仿真程序的方法 ,指出了一条运用 VB和 Matlab结合进行系统仿真的新途径 ,实现了 VB与 Matlab的 Simulink工具箱的交互 ,用户可以方便地在自己的程序中执行 Matlab命令 ,调用其功能丰富的 Simlink工具箱     

基于MCGS的数据采集器驱动程序设计

详细介绍了MCGS设备驱动程序编制原理和前置数据采集器驱动程序的设计方法。并提供了MCGS设备驱动程序的设计框架。