IP视频监控系统中云台控制模块的设计与实现

介绍了网络视频监控系统中云台控制模块的设计与实现,包括简单电路原理说明、单片机控制程序设计和嵌入式系统的驱动及控制程序设计.云台控制属于整个系统的一个功能模块,首先由DSP(BSP-15)将网络用户的云台控制操作解释为符合标准云台控制协议的命令,通过I2C发送命令给单片机(87LPC764),再由单片机通过RS-485串口将云台控制信息转发给云台摄像机,从而完成整个控制过程.     

利用Java实现对云台和镜头的远程控制

结合我国实际情况和未来的发展趋势,开发出基于Java的视频监控系统,实现对云台和镜头的远程控制.系统包括RS-232/RS-485的转换,解码器和云台、镜头以及它们与计算机串口的硬件连接,通过Pelco-D协议,采用Java的扩展类库comm.Jar库进行串口通信.客户端通过套接字对服务器端的云台和镜头进行控制,对于同时来自服务器端和多个远程客户端对云台和镜头的控制所产生的冲突提出了解决方法.系统具有跨平台性.     

浅议RS-232C与RS-485接口技术

本文对比分析了RS-232C与RS-485接口技术,详细论述了提高RS-485总线可靠性与稳定性措施。     

智能楼宇防盗报警系统的应用

设计并实现了一个以微控制器MI24为核心的智能楼宇防盗报警系统.介绍了系统的结构、组成及软、硬件设计.本系统基于RS-485总线,监控主机和监控器之间采用自定义协议进行串行通信.     

基于人脸检测的云台智能控制系统设计

针对安防监控系统中云台手动控制和自动控制不能准确有效地监控入侵目标的缺陷,设计出基于人脸检测的云台智能控制系统。首先介绍了系统的原理及软硬件结构,然后详细介绍了软件部分的人脸检测的Adaboost学习算法原理及使用opencv的人脸检测函数实现人脸检测的过程及结果。接着在云台的智能控制部分讲述中,详细地推导了监控画面的像素距与云台转角的数学映射关系,计算出云台水平与垂直运动的时间过程。最后,通过智能控制的算法流程实现云台的智能控制。实验结果表明:程序实现云台智能控制系统且对于低速的运动的人脸,云台有较好的智能控制效果。     

带有云台信息反馈的视频监控系统软件的开发设计

介绍了带有云台信息反馈的视频监控系统,详细阐述了系统的组成和工作原理,计算机能够通过控制云台摄像头实现视频监控需要的水平、俯仰移动和镜头的调焦、变倍和光圈变化,并处理云台反馈的数据以获得云台的位置信息.探讨了VC6.0串行通信Mscomm控件的应用,对计算机与一体化云台编译码器之间的串行通信过程进行了详细阐述.开发出一套带有云台信息反馈的视频监控软件,具有操作简单,控制可靠,反馈准确,使用方便的优点.     

带有云台信息反馈的视频监控系统软件的开发设计

介绍了带有云台信息反馈的视频监控系统,详细阐述了系统的组成和工作原理,计算机能够通过控制云台摄像头实现视频监控需要的水平、俯仰移动和镜头的调焦、变倍和光圈变化,并处理云台反馈的数据以获得云台的位置信息。探讨了VC6.0串行通信Mscomm控件的应用,对计算机与一体化云台编译码器之间的串行通信过程进行了详细阐述。开发出一套带有云台信息反馈的视频监控软件,具有操作简单,控制可靠,反馈准确,使用方便的优点。     

施耐德电气旗下品牌派尔高（Pelco）

随着我国安全防范监控技术的快速发展，云台摄像机以其独特的性能优势，被广泛地应用于各类治安监控领域。目前，云台摄像机多用于监控大型的公共区域，其优势表现在诸多方面，比如：在云台的文持下，云台摄像机可完成旋转、倾斜、缩放等操作，可覆盖较大面积的监控范围；它在较大区域内可跟踪目标，并可放大查看所捕获目标的细节特征；它可以以移动的方式部署在需要监控的站点，从而降低整个监控系统的成本。     

基于闭环控制的云台通信协议设计

视频监控系统设备间通信已经采用数字通信协议,协议质量对视频监控系统的运行起着至关重要的作用。市面上典型的云台通信协议(如PELCO-D、PELCO-P)为单向开环控制协议,操作台只能发送命令给云台,而云台没有对应命令的反馈信号,因此操作台不能确认云台的运行状态,严重影响系统的可靠性。针对主流云台通信协议的此种缺陷,设计了一种基于闭环控制的云台通信协议,能够实现操作主机与云台之间的可靠信息交互及云台的精确控制,适应现代视频监控系统的发展。     

探析安防监控云台机的应用及常见故障检排

安防监控云台机在安防行业中起着至关重要的作用,对其使用和维护不当会引发诸多故障.本文针对安防监控云台机的性能特点,介绍了安防监控云台机的选择技巧、安装使用、故障排查等相关内容,提供了云台视频信号干扰故障的检修实例.     

基于802.11n无线传感器网络的巷道人员定位技术研究

针对现阶段矿井人员定位系统定位精度低、成本高、可靠性差等问题,提出了一种基于802.11n无线传感器网络技术的真三维人员定位系统,该系统根据功能特征划分为现场设备管理层、系统运行监控层和地面监控管理层。工作时,定位分站将移动节点通过无线网络传输过来的位置坐标信息通过RS-485总线传输到光纤冗余网中,紧接着将位置坐标信息通过CAN现场总线传输到地面数据服务器内进行解压、分析处理和可视化显示。实验结果表明:当加权因子k取1.1时,该系统在井下巷道测试环境中的平均误差仅为1.15 m,且长期运行无故障,具有较高的定位精度和可靠性,降低了成本。     

危险化学品公路运输事故新特点及对策研究

统计分析了2008年1月～2010年5月我国发生的485起危险化学品公路运输事故。从事故发生的原因、事故涉及的化学品、事故造成的危害、事故发生的月份分布及年份变化等几个方面,分析了近年来危险化学品公路运输事故的新特点及变化规律。经统计分析,道路交通事故是引发危险化学品运输事故的主要原因之一;侧翻是危险化学品车辆最容易发生的道路交通事故;而随着我国高速公路的迅猛发展,追尾造成的危险化学品运输事故数量呈上升趋势;危险化学品公路运输过程中易燃液体事故起数最多,爆炸品和毒性物质事故造成的人员伤亡最严重;春节前后取代夏季,成为近两年危险化学品运输事故高发期。针对这些特点,对我国危险化学品公路运输安全管理与监控提出了建议。     

基于GM(1,1) Markov的危化品道路运输事故与交通事故预测及关系研究

为准确预测我国危化品道路运输及交通2类事故数量趋势,探究其内在联系,在单一的灰色GM（1,1）模型基础上与马尔科夫过程组合形成灰色GM（1,1）—马尔科夫预测模型,以2013—2017年2类事故数量的原始序列探讨了该组合预测模型的实际应用,采取平均相对误差、均方差比值、小误差概率对模型进行精度检验。研究结果表明:在组合预测模型较优情况的研究中,2类事故数量历年来波动性相似,因危险化学品自身的性质、包装和装卸使得2类事故量变化频率存在偏差;2018—2019年的危化品道路运输事故分别为485起和480起,交通事故分别为225 294起和234 454起。     

多手段综合分析特厚煤层分层开采覆岩破坏高度

为研究特厚煤层分层开采过程中已采工作面上覆围岩破坏高度,以老虎台矿83002已采工作面为例,分别采用EH-4物理探测、数值模拟和微震监测等多种手段进行分析论证。EH-4探测确定了垮落带和裂隙带位于油页岩层内,高阻区位于绿色页岩和砂砾岩的交界面,F1断层处出现离层空间,数值模拟和微震监测对该结果进行了验证;数值模拟和微震监测综合确定了覆岩破坏高度为400～485 m,为累计采高的6.3～7.5倍。研究成果可对下一分层83003工作面的安全开采进行指导,为类似条件矿井提供借鉴。     

碱性水对煤自燃特性影响实验研究

为了研究碱性水对煤自燃特性的影响,选取葫芦素煤矿102工作面煤样作为实验煤样,利用STA-449C型同步热分析仪进行热重实验,研究加入PH=8 NaOH的煤样与原煤以及加入蒸馏水煤样在空气氛围中燃烧失重、放热量、特征温度点等变化规律,并根据Coats-Redfern积分模型计算了3种煤样燃烧反应动力学参数（活化能、指前因子）。研究结果表明:加入碱性水的2号煤样失重量较1,3号少,燃烧失重速率更低;2号煤氧化燃烧温度区间缩短,着火温度点升高,放热量少,比1,3号煤分别少485.0,480.4 J/g;3种煤样反应机理基本遵循一级化学反应函数,2号煤各段活化能高于1,3号煤,但2号煤失水活化能小于3号,表明碱性水具有抑制煤自燃效应。     

An awareness campaign decreases distracted driving among hospital employees at a rural trauma center

Abstract

Objective: To evaluate whether an educational campaign on distracted driving will have an impact in a given community.

Methods: Investigators were stationed in an employee parking lot of a 256-bed hospital to determine baseline distracted driving followed by a 4-week hospital-wide distracted-driving awareness campaign. The campaign included signs/posters in the hospital, a booth outside of the cafeteria with flyers, a large banner in the employee lot and an opportunity for people to sign a pledge form to drive distraction free. The same employee lot was observed at the same time of the day to re-assess distracted driving immediately following the campaign. The observations were repeated again one year later to evaluate the short and long-term impact of the campaign.

Results: A total of 485 vehicles were observed pre-campaign, identifying 170 (35%) distracted drivers at baseline. The awareness campaign resulted in 525 people pledging to drive distraction free. Following the campaign, 495 vehicles were observed and the number of distracted drivers was 64 (12.9%), showing a significant decrease in the number of distracted drivers by 22.1% (p?<?0.01). One year later, 530 drivers were observed with 150 (28%) displaying one form of distraction.

Conclusions: A local distracted driving educational campaign resulted in a significant decrease in the number of distracted drivers immediately following the campaign. However, one year after the campaign, there was an increase in distracted driving. The proportion of distracted drivers was still significantly lower than the initial rate of distracted-drivers.     

洁净室空气洁净度评价的模糊模式识别方法

洁净室空气洁净程度的高低属于模糊概念,将各评价样本实测指标矩阵转变为相对隶属度矩阵,同时将各标准模式指标标准值矩阵转变为指标准相对隶属度矩阵,以全体样本对于各标准模式间的加权广义距离平方和最小建立目标函数,经构造拉格朗日函数,建立了洁净室空气洁净度评价的模糊模式识别模型。斗净室洁净程度评价是一个多目标评价问题,提出了确定指标权重的主、客观结合法,即先建立求解各指标权重的迭代模型并求出指标权重的初始值,然后根据评价的经验,采用重要性语气算子调整各指标的相对隶属度,对初始值进行调整,归一化后得到合理的指标权重值,经计算实例验证,本建立的模式识别方法物理意义明确,评价结果符合实际。     

Numerical simulation of hydrogen–air detonation for damage assessment in realistic accident scenarios

An accidental hydrogen release within an equipment enclosure may result in the presence of detonable mixture in a confined environment. From a safety standpoint, it is then useful to assess the potential for damage. In that context, numerical simulation of the sequence of events subsequent to detonative ignition provides a useful tool, although with obvious limitations. This article describes the procedure, summarizes two case studies, and reviews the limitations. First, a hydrogen dispersion pattern is obtained from numerical simulation of dispersion, using a commercial package designed primarily for incompressible flow. This dispersion cloud is then used as the initial condition in an inviscid, compressible, reactive flow simulation. To force detonative ignition, a sufficiently large amount of energy is deposited in a small region that corresponds to the ignition location. Chemistry is modeled using a single step Arrhenius model. Because the wave thickness is small compared with the computational domain, a fine mesh is needed, limiting the practicality of the process to two-dimensional geometries. This is the most significant limitation; it is conservative. The two cases described in the paper include an electrolyzer, in which a small release occurs, leading potentially to some damage to the enclosure, and a reformer, in which the consequences are potentially more serious.     

Flameless venting of dust explosion: Testing and modeling

Flameless venting is a sort of dual mitigation technique allowing, in principle, to vent a process vessel inside a building where people are working without transmitting a flame outside the protected vessel. Existing devices are an assembly of a vent panel and a metal filter so that the exploding cloud and the flame front is forced to go through the filter. Within the frame of ATEX Directive, those systems need to be certified. To do so a standard (NF EN 16009) has been issued describing which criteria need to be verified/measured. Among them, the “efficiency” factor as defined earlier for standard vents. This implies that flameless venting systems are basically considered as vents. But is it really so? This question is discussed on the basis of experimental results and some implications on the practical use and certification process are drawn. The practical experience of INERIS in testing such systems is presented in this paper. Schematically, with a flameless vent the pressure is discharged but not the flame so that combustion is proceeding to a much longer extent inside the vessel than with a classical vent so that the physics of the explosion is different. In particular it is shown that besides the problem of the unloading of the confined explosion, there is a highly complicated fluid mechanics problem of a fluid-particle flow passing through a porous media (the flameless device grids arrangement in the filter), which passing surface is progressively reduced. To characterize Flameless venting the problem can be addressed sequentially, considering separately the vent panel and the flameless mesh. A model is proposed to estimate the overall venting efficiency of the flameless vent. However, it does not address the flame quenching issue, which is a different problem of heat exchange between the devices and the evacuated burnt products.     

基于G1法的应急能力评估指标权重的确定

在对城市应急能力评估前,确定应急能力评估指标的权重是重要问题之一。笔者介绍了一种无需一致性检验的方法G1法;分析并提出城市应急能力评估指标,通过实例利用该方法对指标在体系中的权重进行了计算。结果表明,在指标的数量较多的情形下,其计算量较其他方法明显减少,同时该方法的可操作性强,便于使用。