QT图形库下基于OpenType字库的复杂文本显示研究

当前的操作系统和应用软件对复杂文本的少数民族文字处理相当有限,不利于信息的交流.通过对QT图形库下的复杂文本引擎的分析,得出基于OpenType字库技术复杂文本显示技术一般过程,对需要支持少数民族文字的操作系统和软件设计有一定的帮助作用,可用于指导支持民族文字的软件设计.     

基于嵌入式可信系统的可容忍非信任组件的计算平台

针对现在大量遗留系统中存在的非信任组件会造成终端安全操作隐患这一问题,提出了一种基于嵌入式可信系统的可容忍非信任组件的计算平台,该平台在不改变现有终端硬件结构以及上层操作系统的前提下,允许非信任组件的存在,并采用虚拟机等技术保证非信任组件不会造成严重的安全威胁。另外,基于IMA与SB两种度量模型为该平台设计了新的完整性度量模型,该度量模型借鉴IMA对嵌入式系统进行度量,而对于上层平台则使用由虚拟机支持的SB模型,以保证平台的可信启动、进程的可信加载、程序的可信运行安全有效。     

一种无线传感器网络应用系统的中间件设计与实现

为了降低获取异构传感器网络数据的复杂性,通过对无线传感器网络(WSN)接入异构网络技术的研究,提出了一种无线传感器网络应用系统的中间件设计方案.该方案是以S3C6410为主处理器的嵌入式开发板作为硬件开发平台,通过AODV路由协议,使多个监测区域的WSN网关和Adhoc网关组建成Adhoc类型的网络,从而解决了无线传感器网络与外部公网无缝隙连接的问题.该方案不但实现了经过WSN网关处理加工后的无线传感器网络数据上传至远程服务器的功能,而且为多个异构无线传感器网络同时接入外部网络提供了一种可靠的解决方法.     

A contact problem for a poroelastic halfspace containing an embedded inextensible membrane

The paper examines the axisymmetric problem of the indentation of a poroelastic halfspace that is reinforced with an inextensible permeable/impermeable membrane located at a finite depth by a rigid indenter. The constitutive behavior of the poroelastic halfspace is described by the three-dimensional theory of poroelasticity proposed by M.A. Biot. The contact conditions between the indenter and the poroelastic halfspace are varied to accommodate both adhesive/frictionless contact and impermeable/permeable conditions. The formulation of the mixed boundary value problems uses the stress function approaches applicable to semi-infinite domains. Successive applications of Laplace and Hankel integral transforms are used to reduce the mixed boundary value problems to sets of coupled Fredholm integral equations of the second kind. These integral equations are solved using numerical approaches, applicable both for the solution of the systems of coupled equations and for Laplace transform inversion, to examine the time-dependent displacement of the rigid indenter. The analytical-numerical estimates for the time-dependent displacements of the rigid indenter are compared with results obtained using a finite element approach.     

Embedded discontinuity approach for coupled hydromechanical analysis of fractured porous media

In this paper, a new continuum approach for the coupled hydromechanical analysis of fractured porous media is proposed. The methodology for describing the hydraulic characteristics invokes an enriched form of Darcy's law formulated in the presence of an embedded discontinuity. The constitutive relations governing the hydromechanical response are derived by averaging the fluid pressure gradient and the discontinuous displacement fields over a selected referential volume of the material, subject to some physical constraints. The framework incorporates an internal length scale which is explicitly embedded in the definition of gradient operators. The respective field equations are derived following the general form of balance equations in interacting continua. The conventional finite element method is then employed for the spatial discretization, and the generalized Newmark scheme is used for the temporal discretization. The proposed methodology is verified by some numerical examples dealing with a steady-state flow through fractured media as well as a time-dependent consolidation in the presence of a discontinuity.     

GPRS车载定位网络服务系统及关键技术研究

随着无线通信技术、地理信息技术和GPS定位技术的发展以及当前社会经济发展的需要,GPS车辆定位监控系统已在智能交通、物流管理及特种车辆的监控调度等方面得到了广泛应用,并且带来了很大的经济效益和社会效益.随着嵌入式技术的不断研究和发展,嵌入式技术已应用到很多方面,其技术变得越来越成熟,其成本在不断降低.本文通过对GPRS特点简介,对GPRS车载定位网络服务系统结构及嵌入式GPS/GPRS车载定位的关键技术进行了研究.     

嵌入式移动GIS研究

嵌入式移动GIS能够弥补传统静态GIS在运动对象空间分析方面的不足,正成为地理信息科学领域新的研究热点。本文首先提出了嵌入式移动GIS的体系结构,进而分析了系统涉及的若干关键技术,最后开发了一套集成GPS、GSM、GPRS、PDA、GIS的应用系统。     

基于VxWorks的RapidIO互连系统的设计与实现

RapidIO高速串行总线作为新一代嵌入式系统互连总线,具有高速度、低延时、高可靠性等特性,同时能够很好地适应高速互连协议的规模化应用的要求。RapidIO互连架构是一个开放的标准,可应用于连接多处理器、存储器和通用计算平台。介绍了RapidIO互联体系的层次、主要协议以及系统拓扑结构,在MPC8548E处理器及Tsi578交换芯片组成的RapidIO互连系统硬件平台上进行基于VxWorks操作系统的RapidIO驱动开发,实现Ra-pidIO的主要功能,如读写、消息传递、门铃事务等,验证了RapidIO的基本功能。     

亚毫米级预埋件定位技术研究

大型精密设备预埋件安装存在精度要求高、施工影响大、工期短等特点,需要采取稳定可靠的定位安装措施来保证预埋件亚毫米级精度要求,本文通过对预埋件安装及浇筑混凝土过程中误差来源的分析与相关公式的推导,探讨消除或减弱定位及施工对预埋件安装精度影响的方法,并用实例进行了说明和验证.     

嵌入式GIS导航系统中快速偏航算法的设计与实现

诸如汽车拉力赛等特殊领域的车载导航系统中,需要在资源有限的嵌入式GIS平台上,满足地图快速刷新前提下实现偏航算法的实时性,为此本文改进了比较耗时的欧氏浮点距离计算公式,采用定点整型数描述空间位置,并用移位运算代替乘除计算.理论分析和测试结果表明,改进算法带来的相关误差符合导航需求,改进算法显著提高了一般偏航算法的实时性...