Auto-scanning and visualizing system for the acoustic field of transducer

This paper presents an automatic scanning and visualizing system for ultrasound field of a planar piston transducer. This system consists of a water tank with wedge absorber, stepper motors driver, system controller, a planar piston transducer, a needle-type hydrophone and data processing software. Our software realizes the processing and displaying of ultrasonic data, which are acquired by adjusting accurately positions of the hydrophone and transducer that are driven by stepper motors. And the ultrasonic field is represented by employing 1D, 2D or 3D graphs of data, respectively. Experimental results show that this auto-scanning and visualizing system provides a more spatial structure of ultrasonic field and reveals a more characteristic of ultrasonic beam radiated by the planar piston transducer.     

Participation of Danish and immigrant cleaners in a 1-year worksite intervention preventing physical deterioration

Worksite health promotion is seldom offered to workers who are low-educated and multi-ethnic, possibly due to an assumption that they are more reluctant to participate. Furthermore, little has been done to promote health at female-dominated workplaces. The main aim of this study was to investigate differences in participation among immigrant and Danish cleaners throughout a 1-year randomised controlled study tailored to cleaners and carried out in predominantly female workplaces. No significant differences in ethnicity were found in consent and participation throughout the 1-year intervention. Dropout was equally distributed among Danish and immigrant cleaners. This study indicates that a worksite health promotion intervention among a female-dominated, high-risk occupation such as cleaning can be equally appealing for Danes and immigrants. PRACTITIONER SUMMARY: This study provides insight about participation of Danish and immigrant cleaners in a worksite health promotion intervention in a predominantly female occupation. For attaining high participation and low dropout in future worksite health promotion interventions among cleaners, the intervention ought to not only target the ethnic background of the workers, but also to be specifically tailored to the job group.     

家居物联实时终端设计与实现

物联网已成为当今各国重点科技发展战略。家居物联网因与人类生活密切相关,具有广阔的市场空间,在业界引起了广泛关注和积极研究。立足于实际家居物联网需求,特别考虑到实时性能和成本因素,设计了一套针对家居物联网的终端系统。该系统采用eCos(嵌入式可配置操作系统)作为嵌入式操作系统,开展了系统移植和驱动移植工作,利用eCos的实时功能设计来满足终端的实时性需求,以其开源性节约成本,为家居物联终端普及提供条件。此外结合家居物联网结构特点,通过在eCos系统上移植OLSR路由协议来实现家居网络的路由,增强网络的鲁棒性,为家居物联网的实时传输应用提供了良好支撑。总体看来,该家居物联终端具有优异的系统实时性和较高的经济适用性。     

基于VxWorks系统的二维硬件加速显示驱动技术

针对当前VxWorks系统图形显示驱动已无法满足用户需求的问题,提出了一种基于二维(2D)硬件加速引擎的图形显示驱动技术,实现了UGL的二维硬件加速、硬件光标、硬件双缓冲、Overlay覆盖等功能,提高了VxWorks系统的图形显示性能,满足了实时系统的应用需求.目前该设计已在多型海军装备中得到应用验证.     

在内核下的BootLoader自动更新方法

目前的BootLoader更新方法仅适用于单块目标板的调试阶段,无法实现批量更新。为此,提出一种在内核下的BootLoader自动更新方法。该方法提取新BootLoader镜像文件中的有效数据,并将其保存到以“.h”结尾的文件中,利用特制的Flash驱动程序及该类型文件生成特制的内核,通过外部移动存储设备,将特制内核更新到嵌入式系统中,特制内核启动后将自动更新BootLoader,从而完成BootLoader的批量更新。     

基于WDF框架的PXI-E数据采集卡驱动的设计与实现

主要介绍了WDF驱动模型的特点,分析了WDF驱动的基本结构,主要探讨基于WDF的PXI-Express总线的高速数据采集卡驱动的基本开发流程,说明了如何通过DMA实现高速数据传输,以及驱动与应用程序之间的通信机制的设计和同步访问的实现.     

基于S3C2440A的手持式分析诊断仪电池电量计模块

采用DS2786B芯片,设计并实现了一款基于S3C2440A处理器的手持式分析诊断仪电池电量计模块。介绍了该模块的硬件电路设计,以及基于WindowsCE5．0操作系统的驱动程序和应用程序的开发。实验结果表明,该模块工作稳定可靠,能精确地测量电池电量并实时在用户界面显示,在嵌入式便携设备中有很好的应用前景。     

一种分布式网站安全防护系统

为了及时、高效地阻止黑客对网页文件的篡改,并对被篡改的页面文件进行及时修复还原,提出了一种分布式"过滤驱动技术+事件触发技术+核心内嵌技术"架构的网站安全防护系统。事件触发技术负责自动实时监测,若有网页被篡改,通过过滤驱动技术和核心内嵌技术立即删除被篡改网页,停止Web服务。与传统的网页防篡改产品相比,系统可以对网页的非法篡改做出更为敏捷快速的反应,对系统资源占用更少。同时兼容其他安全产品,形成深度防护体系,最大限度地保障受保护网站的安全。     

High power pulsed lasers

Pulsed high power lasers can deliver sufficient energy on inertial fusion time scales (0.1–10 ns) to heat and compress DT fuel to fusion reaction conditions. Several laser systems have been examined for application to the fusion problem. Examples are Ndglass, CO₂, KrF, and I₂, etc. A great deal of developmental effort has been applied to the Ndglass laser and the CO₂ gas laser systems. These systems now deliver >10⁴ kJ and >20×10¹² W to inertial fusion targets. The Nova Ndglass laser is being constructed to provide >200 kJ and >200×10¹² W of 1 m radiation for fusion experimentation in the mid-1980s. For inertial fusion target gain, >100 times the laser input, it is expected that the laser must deliver 3–5 MJ of energy on the 10–20 ns time scale. This paper reviews the developments in laser technology and outlines approaches to construction of a 3–5 MJ driver.     

基于模糊灰色理论液压压桩机工作可靠性评价方法

液压静力压桩机是一种大型桩基础施工设备，其工作可靠性问题十分重要，由于其各影响因素之间存在灰色模糊特征，传统评价方法很难对其进行正确的评价。本文利用模糊灰色理论，构建了基于模糊灰色理论静力压桩机工作评价可靠性模型，经过试验研究证明利用该方法对静力压桩机进行评价，其评价精度、可靠性较传统方法显著提高。