4D MRI Flow Coupled to Physics‐Based Fluid Simulation for Blood‐Flow Visualization

Modern MRI measurements deliver volumetric and time‐varying blood‐flow data of unprecedented quality. Visual analysis of these data potentially leads to a better diagnosis and risk assessment of various cardiovascular diseases. Recent advances have improved the speed and quality of the imaging data considerably. Nevertheless, the data remains compromised by noise and a lack of spatiotemporal resolution. Besides imaging data, also numerical simulations are employed. These are based on mathematical models of specific features of physical reality. However, these models require realistic parameters and boundary conditions based on measurements. We propose to use data assimilation to bring measured data and physically‐based simulation together, and to harness the mutual benefits. The accuracy and noise robustness of the coupled approach is validated using an analytic flow field. Furthermore, we present a comparative visualization that conveys the differences between using conventional interpolation and our coupled approach.     

Interactive Simulation of Rigid Body Dynamics in Computer Graphics

Interactive rigid body simulation is an important part of many modern computer tools, which no authoring tool nor game engine can do without. Such high‐performance computer tools open up new possibilities for changing how designers, engineers, modelers and animators work with their design problems. This paper is a self contained state‐of‐the‐art report on the physics, the models, the numerical methods and the algorithms used in interactive rigid body simulation all of which have evolved and matured over the past 20 years. Furthermore, the paper communicates the mathematical and theoretical details in a pedagogical manner. This paper is not only a stake in the sand on what has been done, it also seeks to give the reader deeper insights to help guide their future research.     

移动视频通信业务的应用研究

移动视频通信业务是通过移动网络和移动终端为移动用户提供的一种新型通信服务。本文主要研究了基于3G和Vo LTE技术的移动视频通信业务的应用。分别从技术、资费、用户体验、互通性四个方面对两种移动视频通信业务进行了分析和对比。     

Enantiomer-based specificity in pheromone communication by two sympatricGnathoirichus species (Coleoptera: Scolytidae)

The aggregation pheromone ofGnathotrichus retusus was isolated and identified as (S)-(+)-sulcatol (6-methyl-5-hepten-2-ol). In laboratory and field experiments,G. retusus responded to (S)-(+)-sulcatol, but not to (±)-sulcatol, which was attractive to the sympatric species,G. sulcatus. G. sulcatus did not respond to optically pure (S)-(+)-sulcatol, but began to respond when 1% (R)-(–)-sulcatol was present in an enantiomeric mixture.Research supported by the National Science Foundation, U.S.A. (Grant BMS-74-13643), and the Natural Sciences and Engineering Research Council of Canada (Co-op grant A0243 and Operating Grant A3881 and A3785).     

一种双权重参数的RFID防碰撞Q值算法研究

标签防碰撞算法是RFID技术研究的热点,也是高强度、大规模应用的关键。在研究了EPC-C1G2标准防碰撞机制中推荐的Q值调整算法的特点后,针对其不足,提出了一种双参数的Q值调整算法——ODWQA,详细阐述了算法的思想、运算流程和关键参数确定方法。在ODWQA算法中,将单一的调整参数c分解为两个权重参数c1和c2,分别对应着碰撞和空闲两种情况,用来调控碰撞时隙和空闲时隙的个数。接着通过实验分析,确定了在不同Q值条件下权重参数c1和c2的最优取值。最后对ODWQA算法进行了仿真测试,结果表明,该算法能够有效减少碰撞时隙的个数,增大系统的吞吐率,降低标签的识别时延。     

嵌入式Linux系统的3G/4G路由器设计

基于嵌入式Linux系统,设计并实现了一种利用WiFi技术共享3G/4G带宽的无线路由器。该路由器支持UMTS/GSM/CDMA以及TDD/FDD-LTE网络标准,实现了对3G/4G网络各制式的兼容。在详细介绍了该路由器的设计方案后,重点介绍了该路由器无线局域网的组建和3G/4G网络的接入,并实现了无线局域网和3G/4G网络的互通。最后利用多个智能终端设备对该路由器的功能进行了测试,测试结果证明了该路由器设计方案的可靠性和有效性。     

ZigBee和3G的远程无线测光系统设计

设计了基于ZigBee短距离无线通信技术与3G远距离无线通信技术相结合的远程无线测光系统;该系统处理器选用的是三星S5PV210处理器,短距离无线通信模块采用TI公司的CC2530芯片,3G上网卡设备用的是中兴MF190无线上网模块。文中给出了系统具体的软硬件设计方案。结果表明,该系统可以达到稳定高效的监测效果,具有良好的实用性和应用价值。     

警用移动信息系统安全解决方案

当前,在社会矛盾复杂化、警务工作效率必须不断提高的大背景下,我国各地方公安机关陆续将警用移动信息系统纳入信息化建设的重要指标。为了向公安各部门一线民警提供快捷、方便的实现信息共享渠道,就必须在现有的公安信息系统的基础上,发展出可移动的信息处理系统。由于各地公安机关都是各自开发所需的相关业务的专项警务信息系统,容易在安全设计上存在只注重功能轻视安全问题的错误,警务人员在使用这些系统提高工作效率时存在公安警务工作泄密、公安资料不安全等问题。因此,在以现代无线通讯技术和互联网技术相结合产生的移动互联网技术的飞速发展中,为警用移动信息系统提出安全解决方案提供了必要的技术基础。在分析警用移动信息系统网络架构、安全需求及建设现状的基础上,本文设计并实现了以移动3G技术为基础的Socket方式访问的警用移动信息系统。     

三等径圆管曲面连接的连续性研究及实现的方法

本文详细叙述和分析了曲线和曲面连接的位置连续(GO)、相切连续(G1)和曲率连续(G2),得出曲率连续(G2)光滑度最高的结论.最后举例说明了三等径圆管如何实现G2曲面连接的方法.     

TD-SCDMA住宅小区覆盖综合解决方案

TD-SCDMA住宅小区覆盖的解决并没有完全统一的标准。文章分析当前TD-SCDMA小区无线覆盖的状况,从移动通信无线信号覆盖的角度出发对住宅小区进行归纳分类,并针对不同住宅小区的特点提出相应的无线覆盖解决方案,从而解决居民小区无线信号的覆盖问题和网络容量问题。