POI共建LTE双路室分系统建设成本分析

详细论述了POI系统实现原理、POI系统技术特点、LTE室分双路常见解决方案;结合工程实际案例,着重论述了多家运营商是如何通过POI共建室分系统实现LTE室分双路建设方案的;详细分析了POI共建节约室分建设投资情况,为LTE双路室分系统共建方案的选取提供宝贵经验。     

A randomized double‐blind crossover study of indoor air filtration and acute changes in cardiorespiratory health in a First Nations community

Few studies have examined indoor air quality in First Nations communities and its impact on cardiorespiratory health. To address this need, we conducted a crossover study on a First Nations reserve in Manitoba, Canada, including 37 residents in 20 homes. Each home received an electrostatic air filter and a placebo filter for 1 week in random order, and lung function, blood pressure, and endothelial function measures were collected at the beginning and end of each week. Indoor air pollutants were monitored throughout the study period. Indoor PM_2.5 decreased substantially during air filter weeks relative to placebo (mean difference: 37 μg/m³, 95% CI: 10, 64) but remained approximately five times greater than outdoor concentrations owing to a high prevalence of indoor smoking. On average, air filter use was associated with a 217‐ml (95% CI: 23, 410) increase in forced expiratory volume in 1 s, a 7.9‐mm Hg (95% CI: ?17, 0.82) decrease in systolic blood pressure, and a 4.5‐mm Hg (95% CI: ?11, 2.4) decrease in diastolic blood pressure. Consistent inverse associations were also observed between indoor PM_2.5 and lung function. In general, our findings suggest that reducing indoor PM_2.5 may contribute to improved lung function in First Nations communities.     

Comparative Study of 9×19 mm Ammunition Combustion Products and Residues

During the last decades, authorities’ awareness on environmental and human health impact at national and international level has increased in the field of small arms ammunition containing lead and antimony. Thus, the evolution of environmental policies regarding production and use of heavy metals and their compounds, especially in EU countries, implied extensive studies on the environmental implications of 9×19 mm caliber ammunition use, especially in indoor shooting ranges. In this context, the paper describes the experimental studies performed on Pb‐containing conventional FMJ (full metal jacketed) ammunition and comparative measurements on new ammunition designed for training. The combustion products and residues from conventional Pb‐containing ammunition and Cu‐based “greener” ammunition were compared in terms of gaseous products, metal concentration in aerosols and metal concentrations in solid residues. Gas emissions and solid residues were measured for four different types of ammunitions. The results showed that the copper content of the residue is significantly higher in case of Cu‐containing composite bullets. For the ammunition equipped with Pb bullet, an important percentage of the Pb residue is generated by erosion of the exposed part of the bullet core. On the other hand, the ammunition containing Cu‐composite bullet generates large quantities of Cu residues, which have similar environmental impact and less impact on human health. Gas analysis indicated the presence of CO and NO_x and, surprisingly, high concentrations of HCN, CH₄, and NH₃. Lower gas concentrations are obtained for the composite bullets due to an incomplete combustion of gun propellant.     

局部纹理特征改进空闲车位智能检测算法

针对车辆数量的爆炸式增长而智能停车场车位检测速度慢、正确率低的问题,提出了一种基于局部二值纹理特征改进的空闲车位检测算法,算法首先将监控摄像机采集的车位图像降噪滤波后转化为局部二值模式,然后通过结构模板集提取图像的局部二值纹理特征,作为空闲车位和有车车位的识别特征,最后通过核Fisher判别方法实现空闲车位的检测.实验...     

A novel indoor geo-location method using MIMO array

In a Multiple-Input Multiple-Output （MIMO） Orthogonal Frequency Division Multiplexing （OFDM） based Wireless Local Area Network （WLAN） system, both Access Points （APs） and Mobile Terminals （MTs） are configured with multiple antennas, to make novel indoor geo-location method possible. In this paper, we presented a novel Least Square Support Vector Machine （LS-SVM） based data fusion algorithm to fuse signal strength measurements for indoor geo-location using only a single AP with MIMO arrays. We evaluate our proposed algorithms under indoor environments by MATLAB simulations. Simulation results show that our MIMO-based algorithm is superior to conventional least square algorithm.     

等离子体室内空气净化技术研究成果与探讨

讨论了绝缘屏障放电和脉冲电晕放电应用于空气净化的实验,并比较了实验结果;研究了用交流屏障型等离子体反应器进行香烟烟雾气味控制的实验,并对结果进行了分析;阐述了等离子体杀菌消毒的原理,研究了不同菌种的平面试样实验。     

室内无线传感器网络及其应用

介绍了传统无线传感器网络的起源、发展和现状,分析了室内环境对传统无线传感器网络技术的挑战,提出了一种新颖的室内无线传感器网络节点的构架设计方案;最后展望了室内无线传感器网络技术的应用前景。     

用于矿山等极端环境中的高精度定位算法

高精度室内定位技术在矿山、建筑、施工等多种极端环境下都有需求。基于超宽带通信(Ultra Wideband,UWB)的室内定位技术能够提供较高的定位精度,但超宽带信号易受到障碍物的干扰,并且在类似矿山等极端环境中,障碍物不可避免。因此,超宽带非视线传输(Non-Line-of-Sight,NLoS)测距成为当前的一个研究热点。当前研究大多集中在识别和消除非视线传输对超宽带测距的影响上,实际应用中,大多数情形下超宽带信号根本无法穿透障碍物,会导致定位标签只能够与2个或1个信标节点通信,但完成三边定位至少需要3个信标节点。为此,提出了一种基于目标行为分析的定位算法,该算法能够在短时间内仅剩余一个信标节点与标签通信时,也可实现高精度定位。该算法以超宽带通信为基础,使用信号飞行时间(Time of Flight,TOF)算法测距并定位。通过分析信号正常时的目标运动轨迹来判断其速度和方向,当信号不正常时(可通信的信标节点减少),可利用预测的速度和方向参数来实现辅助定位。将该算法部署在一个基于超宽带定位的系统中进行了测试,结果表明:当能够与标签通信并完成TOF算法的信标节点数量少于3个时,基于NLoS传输识别和消除的算法无法完成定位,而基于目标行为分析的定位算法依然能够实现定位,在单信标节点区域的平均定位误差为0.93 m,最大误差为1.41 m,在2个信标节点测距的区域,平均定位误差为0.64 m,最大误差为1.2 m。     

有机气体污染物对室内空气质量的影响初探

室内空气的品质已经越来越受到人们的关注,室内环境的污染物主要是是来源于建筑装饰材料,空肯,服装等生活用品与生活消费品,以及炊事,取暖,致冷空调和吸烟等产生的各种无机化合物和有机化合物,特别是甲醛、苯并[α]芘等严重影响人体健康。在分析了各种室内环境条件对室内空气品质的影响,提出了通过选用环保材料、“烘烤”加速污染物散发和通风换气、进行空气净化等措施来降低污染物浓度,提高室内空气质量。     

华侨大学厦门校区图书馆中庭夏季室内热环境实测与分析

本文采用自动记录仪,对华侨大学厦门校区图书馆中庭夏季室内热环境实测。根据测得的室内热环境4个参数,结合PMV分析评价华侨大学厦门校区图书馆中庭夏季室内热环境舒适度。主要结论有:(1)华侨大学厦门校区图书馆在开窗和闭窗状态时,中庭温度随着高度的增加而升高;(2)华侨大学厦门校区图书馆在开窗和闭窗时中庭温度差不多,但是开窗时候湿度变化的曲线幅度范围比闭窗的时候大。(3)华侨大学厦门校区图书馆中庭PMV值随着高度的增加而升高,热舒适性随着高度的增加而下降;(4)华侨大学厦门校区图书馆在夏季时不论在开窗还是闭窗状态下,中庭的室内热环境都处于不舒适的范围内。