一种基于MI-Simba算法的香烟烟雾识别方法*

香烟烟雾对环境条件敏感以及多特征间存在冗余,都导致无法在视频监控中准确进行烟雾识别,因此提出一种高维互信息与Simba特征加权相结合的算法(MI-Simba).首先采用视频特征提取方法获取烟雾统计度量特征、颜色布局特征和动态特征,构建初始特征向量;然后利用MI-Simba算法进行自动更新,构建该环境下最优特征组合;最后采用直推式支持向量机进行分类识别.针对室内和楼宇内场景,自建封闭空间吸烟视频数据集,采用5倍交叉策略进行比较验证,实验结果验证该算法在识别率和灵敏度两方面的有效性和优越性.     

Measurement and Account Method for the Available Standing Time of a Smoke Screen Applying the Diffusion Equation

The available shielding area of a smoke screen is an important parameter to evaluate its protection capability. It varies with time according to a parabola equation, which could be obtained by the diffusion equation and a few measured data. The available standing time which could satisfy the request of rating area can be calculated. The process of deriving the equation, the experimental procedure and the method of data collecting and processing is presented in detail in this paper. The calculated result is compared with engineering experience to verify the method.     

进气喷甲醇降低柴油机加速冒烟的研究

针对柴油机瞬态工况排放黑烟的现象,采用同步往进气道喷甲醇加以抑制的方法进行了研究.为此开发了一套根据发动机工况变化的甲醇喷射的电控系统.在一台高速非增压直喷柴油机上对进气喷甲醇和纯柴油的瞬态烟度排放两种情况进行了试验对比研究.结果表明,以城市公交车的起步加速和加载加速工况以及发动机高低转速下的增转矩瞬态工况为对象,进气喷甲醇的方法可以减少烟度排放达到50%以上,说明采用进气喷甲醇为柴油机解决冒黑烟问题提供了一种技术途径.     

袋式除尘器与电除尘器在选型方面的比较

从工艺要求，基建投资和维修难易方面对袋除尘器和电除尘器进行比较，为设计选型提供依据和参考。     

低烟无卤阻燃色条光缆的研制

本文主要介绍了低烟无卤阻燃色条光缆的研制，包括该产品的护套工艺流程、低烟无卤阻燃护套料的性能、对挤出机的要求、烘干工艺、温度控制、色母料配比、色条缆模具设计等。     

Simulation of smoke from a burning vehicle and pollution levels caused by traffic jam in a road tunnel

Detailed analyses of smoke movement from a burning vehicle in a road tunnel have been carried out for the westbound Melbourne City Link tunnel. The time-averaged equations for velocity, pressure, temperature, and mass fraction of emissions were solved for transient condition using the CFD software FLUENT 6.0. For the analysis, a burning bus was assumed to release an equivalent energy of burning 500 l of diesel in 6 min, with vehicles upstream of the fire at a standstill. On the other hand, the vehicles downstream of the fire had enough time to escape from the tunnel through the exit portal. Due to the action of jet fans, most of the smoke was pushed downstream of the fire. The smoke had also dispersed about 55 m upstream of the fire, putting the passengers in this region at great risk. The emissions released from the vehicles in the jam, with their engines running, also posed a threat to human health. Within 8 min after the fire had started, the mass concentrations of O₂, CO₂ and CO were in the ranges of 0.12–0.15, 0.08–0.11 and 0.0006–0.0014, respectively. Therefore, quick evacuation of the passengers is essential in the event of a fire in the tunnel.     

浅析某商场暖通空调设计

本文从空调形式、冷热源的选择、空调水系统、控制方式、气流组织、防火排烟等方面介绍了某商场暖通设计。     

基于模糊神经网络的烟度检测系统的研究

本对全流消光式烟度检测系统中的不确定因素进行校正，归结为模糊规则，并用模糊神经网络来提取这种规则，实现了烟度检测系统的误差校正。仿真分析表明，模糊神经网络应用于烟度的检测是可行的。     

国外军用发烟器材发展现状与趋势

叙述了国外军用发烟器材的发展历史，现状以及发展趋势。     

发烟弹扩爆过程及其扩散影响因素分析

通过发烟弹扩爆和烟幕在大气中扩散两个过程的分析，就影响发烟弹烟幕形成及其浓度分布的主要因素进行了探讨，提出了发烟弹扩爆后烟云形成时初始参数及相关气象条件的估算方法，分析结论为烟幕浓度的估算提供了理论依据。