Despite cities being recognized as being potential sources of microplastic pollution to the wider environment, most surveys of COVID-19 plastic-based litter have been undertaken through linear transects of marine beac...Despite cities being recognized as being potential sources of microplastic pollution to the wider environment, most surveys of COVID-19 plastic-based litter have been undertaken through linear transects of marine beaches. For the far fewer number of studies conducted on inland and urban locations, the site-specific focus has primarily been surveys along the length of streets. The present study is the first to specifically assess the standing stock (i.e., moment-in-time) of littered face masks for the entire surface area of urban parking lots. The density of face masks in 50 parking lots in a Canadian coastal town (0.00054 m2 ± 0.00051 m2) was found to be significantly greater than the background level of littering of town streets. Face mask density was significantly related to visitation “usage” of parking lots as gauged by the areal size of the lots and of their onsite buildings, as well as the number of vehicles present. Neither parking lot typology nor estimates of inferred export (various measures of wind exposure) and entrapment (various metrics of obstruction) of face masks had a significant influence on the extent of whole-lot littering. In consequence, modelling of the potential input of mask-derived microplastics to the marine environment from coastal communities can use the areal density of face masks found here in association with the total surface area of lots for individual municipalities as determined through GIS analysis.展开更多
针对目前智能楼宇监测中数据可靠性低、测量点位分散、数据传输实时性不高和误报频繁等问题,提出基于物联网(Internet of Things,IoT)技术的智能楼宇监测系统设计。首先,采用ZigBee技术组建无线传感器网络,实现分散点位传感器数据的收集...针对目前智能楼宇监测中数据可靠性低、测量点位分散、数据传输实时性不高和误报频繁等问题,提出基于物联网(Internet of Things,IoT)技术的智能楼宇监测系统设计。首先,采用ZigBee技术组建无线传感器网络,实现分散点位传感器数据的收集,并将数据通过网关传输到物联网云平台。其次,利用改进的自适应加权算法融合传感器数据,有效提升多传感器检测数据的准确性。系统云平台能够分析和展示传感器数据,而且能够实时查看待测区域的视频图像,预留数据分析接口。应用表明,系统数据测量准确、相对误差较低、稳定性较好。展开更多
鉴于实际生产中工人的能力和加工效率存在差异,本文提出了考虑工人差异性和刀具限制的多资源约束并行机分批调度问题,以最小化最大完工时间、最小化交付时间偏差为优化目标,构建了工人熟练度、刀具资源约束的混合整数线性规划模型,研究...鉴于实际生产中工人的能力和加工效率存在差异,本文提出了考虑工人差异性和刀具限制的多资源约束并行机分批调度问题,以最小化最大完工时间、最小化交付时间偏差为优化目标,构建了工人熟练度、刀具资源约束的混合整数线性规划模型,研究子批数量和大小、机器分配、工人分配、子批加工顺序之间的耦合关系,设计了一种改进的多目标混合灰狼-鲸鱼群算法(manyobjective hybrid grey wolf optimizer and whale swarm algorithm,MO-HGWSA).根据模型特点,设计了一种两阶段编码和解码方案表示问题的可行解;利用多种引导策略提高算法的进化效率;设计了局部搜索策略,增强算法的局部搜索能力.最后引入案例验证算法的有效性,结果表明本文所提算法在收敛性、分布性和解集支配关系方面均优于对比算法.展开更多
文摘Despite cities being recognized as being potential sources of microplastic pollution to the wider environment, most surveys of COVID-19 plastic-based litter have been undertaken through linear transects of marine beaches. For the far fewer number of studies conducted on inland and urban locations, the site-specific focus has primarily been surveys along the length of streets. The present study is the first to specifically assess the standing stock (i.e., moment-in-time) of littered face masks for the entire surface area of urban parking lots. The density of face masks in 50 parking lots in a Canadian coastal town (0.00054 m2 ± 0.00051 m2) was found to be significantly greater than the background level of littering of town streets. Face mask density was significantly related to visitation “usage” of parking lots as gauged by the areal size of the lots and of their onsite buildings, as well as the number of vehicles present. Neither parking lot typology nor estimates of inferred export (various measures of wind exposure) and entrapment (various metrics of obstruction) of face masks had a significant influence on the extent of whole-lot littering. In consequence, modelling of the potential input of mask-derived microplastics to the marine environment from coastal communities can use the areal density of face masks found here in association with the total surface area of lots for individual municipalities as determined through GIS analysis.
文摘针对目前智能楼宇监测中数据可靠性低、测量点位分散、数据传输实时性不高和误报频繁等问题,提出基于物联网(Internet of Things,IoT)技术的智能楼宇监测系统设计。首先,采用ZigBee技术组建无线传感器网络,实现分散点位传感器数据的收集,并将数据通过网关传输到物联网云平台。其次,利用改进的自适应加权算法融合传感器数据,有效提升多传感器检测数据的准确性。系统云平台能够分析和展示传感器数据,而且能够实时查看待测区域的视频图像,预留数据分析接口。应用表明,系统数据测量准确、相对误差较低、稳定性较好。
文摘鉴于实际生产中工人的能力和加工效率存在差异,本文提出了考虑工人差异性和刀具限制的多资源约束并行机分批调度问题,以最小化最大完工时间、最小化交付时间偏差为优化目标,构建了工人熟练度、刀具资源约束的混合整数线性规划模型,研究子批数量和大小、机器分配、工人分配、子批加工顺序之间的耦合关系,设计了一种改进的多目标混合灰狼-鲸鱼群算法(manyobjective hybrid grey wolf optimizer and whale swarm algorithm,MO-HGWSA).根据模型特点,设计了一种两阶段编码和解码方案表示问题的可行解;利用多种引导策略提高算法的进化效率;设计了局部搜索策略,增强算法的局部搜索能力.最后引入案例验证算法的有效性,结果表明本文所提算法在收敛性、分布性和解集支配关系方面均优于对比算法.
