基于Celery的分布式视频计算处理框架

为了实现能够快速高效的使用计算集群解决视频计算问题,提出一种基于Celery的分布式视频处理框架,该框架借鉴了Hadoop的架构设计,提出了API服务器层,JobTracker和TaskTracker的三层架构,并对其进行了优化使之能够兼容计算资源与存储资源的横向扩展和新的计算应用的纵向扩展.详细描述了框架的架构设计和优化设计.实验数据证明分布式计算框架能够高效地利用多节点实现视频计算.     

嵌入式设备电源管理系统设计

随着嵌入式设备在测量领域的大量应用,如何在无固定电源的情况下为其提供稳定可靠的电源己成为嵌入式设备发展亟待解决的问题。鉴于此,设计出一种续航时间长、体积小、性能稳定、通用性强的电源管理系统。首先介绍了基于单片机 STC12C2052AD的电源管理系统硬件设计框架。然后以设计框架为基础,分析了系统硬件各个子模块的工作原理及其实现方法。最后,阐述了系统的软件实现流程,并对系统进行了测试。经测试证明,所设计的嵌入式设备电源管理系统满足设计的需求,为系统设计提供了良好的解决方案。     

桥梁应变数据采集系统

本文介绍了桥梁应变数据采集系统的基本组成和工程应用研究现状,从硬件电路和软件程序两方面描述应变数据采集系统的设计方案,主要研究了系统硬件设计部分的关键技术.提出以芯片TP4065和STC12C2052AD为核心的电源管理系统;设计了基于惠斯通电桥的全新桥路接线方法,实现桥梁重要节点处应变量的检测;并针对应变量最大时实际输出电压较小而降低系统测量精度的问题设计了信号调理电路.系统在桥梁上进行了实验,结果表明,本系统能够提高测量精度,且运行稳定,验证了本文所提方法的可行性与正确性.     

三线阵立体测绘相机高精度时间同步设计方法

为保证图像定位精度,三线阵立体测绘相机需要具有高精度的时间同步功能,研究了一种时间同步设计方法。以 GPS硬件秒脉冲信号做为时间基准,结合总线广播的整秒时刻信息以及相机内部计时器数据来记录成像时刻。详细描述了时间信息产生链路上各部分的设计,通过这种硬件和软件相结合的办法,解决了时间基准和时间精度的问题,实现了三线阵立体测绘相机与整星的高精度时间同步,为图像后期地面处理提供了有力的保障。经过实验验证,三线阵立体测绘相机的时间同步精度为优于15μs,满足图像测绘精度的要求。     

智能变电站二次设备互换性探讨

针对智能变电站二次设备互换性进行了探讨。分析了互换性需要具备的技术条件,并总结了同厂家同型号产品更换、不同厂商功能同类产品的互换、基于通用软硬件平台的装置功能互换三种互换模式的可行性、存在问题和解决方案。针对目前关心的不同厂商功能同类产品互换问题,分别从过程层合并单元智能终端、间隔层保护测控装置、站控层设备角度提出了设备互换性的实施方案,为推进智能变电站二次设备互换性工程实施提供了技术指导。     

Influence of binding layer on the reflective performance of a Au film in vacuum ultraviolet wavelength region

We investigate the influence of the binding layer on the reflectance of a Au film in vacuum ultraviolet (VUV) wavelength region theoretically and experimentally. The reflectance of Au films on quartz glass substrates with an approximately 2 nm binding layer of Ti, Cr, and Ir are estimated and fabricated. Their reflectance in the 115-140 nm wavelength region are measured continuously by the reflectometer located in the National Synchroton Radiation Laboratory. The testing results show that the addition of the binding layer indeed greatly enhances the interfacial adhesion of the Au layer to the quartz glass substrate, but it also exerts a considerably adverse impact on the reflectance of the Au layer in VUV wavelength region. In near normal incidence, the reflectance of the Au layer with a 2 nm thick binding layer is less than 20%, approximately 5% lower than those without the binding layer. The material used for the binding layer has little impact on the reflectance if this layer is thin enough.     

Modeling fire-induced smoke spread and carbon monoxide transportation in a long channel: Fire Dynamics Simulator comparisons with measured data

Smoke and toxic gases, such as carbon monoxide, are the most fatal factors in fires. This paper models fire-induced smoke spread and carbon monoxide transportation in an 88m long channel by Fire Dynamics Simulator (FDS) with large eddy simulation (LES). FDS is now a well-founded fire dynamics computational fluid dynamic (CFD) program, which was developed by National Institute of Standards and Technology (NIST). Two full scale experiments with fire sizes of 0.75 and 1.6MW were conducted in this channel to validate the program. The spread of the fire-induced smoke flow together with the smoke temperature distribution along the channel, and the carbon monoxide concentration at an assigned position were measured. The FDS simulation results were compared with experimental data with fairly good agreement demonstrated. The validation work is then extended to numerically study the carbon monoxide concentration distribution, both vertically and longitudinally, in this long channel. Results showed that carbon monoxide concentration increase linearly with the height above the floor and decreases exponentially with the distance away from the fire source.     

Preparation and Properties of Natural Sand Particles Reinforced Epoxy Composites

An epoxy composite using Cancun natural hydrophobic sand particle as filler material was fabricated in this study. Three point bending tests demonstrated an enhancement of 7.5 and 8.7% in flexural strength and flexural modulus, respectively, of epoxy composite containing 1 wt.‐% sand particles without any chemical treatment involved, compared to the pristine epoxy. Scanning electron microscopy (SEM) studies revealed that the fracture toughness of the epoxy matrix was enhanced owing to the presence of sand particles in an epoxy/sand composite. Through dynamic mechanical analysis (DMA) and thermal mechanical analysis (TMA) methods, it was found that the storage modulus (E′), glass transition temperature (T_g) and dimensional stability of the sand particles/epoxy composites were increased compared to the pristine epoxy. The friction behavior of epoxy/sand system reflected that the microstructure of epoxy composites was steady. These experimental results suggest that Cancun sand, as a freshly found natural micron porous material, may find promising applications in composite materials.