Modification of Evacuation Time Computational Model for Stadium Crowd Risk Analysis

The complexity of the evacuation process is associated with the flow of occupants through various egresses available inside the building. Several methods and algorithms are now available to analyse the problem related to evacuation. In the present paper an algorithm, evacuation discrete time model (EDTM) has been presented to analyse the building egress evacuation time problem with previous works. The algorithm is based on the crowd flow theory and uses discrete computational approach to identify various widths of egresses available for movement of the people, which is more accurate and practicable because the crowd flow rate is variable. The developed model has been compared with an existing model to show the capabilities of the developed algorithm. A case of stadium stand egress is chose for the validity of EDTM, and a comparison of EDTM, previous model and computer simulation indicates that both the EDTM and the simulation curves were found to give better predictions than the previous model. Based upon the comparison analysis with stranded crowd and evacuation crowd at a certain time, EDTM shows great value in explaining the cause of stampede-trampling and crushing incident of egress or narrow passage zone.     

基于铁路客运专线的旅客联合运输安全问题研究

系统分析了客运专线联合运输存在的主要安全问题及其产生原因。指出旅客联合运输安全问题的关键在各种运输方式的衔接处,其核心因素包括:信息不共享、安全管理缺乏统一规范、交通枢纽软硬件设施有缺陷3个方面,进而针对上述缺陷问题提出相应措施,采用安全审计方法来具体地实现对联合运输安全问题的整改、提高系统安全性能,并对交通枢纽疏散进行案例分析。     

特长公路隧道内的横通道间距和车行间距研究

隧道火灾,尤其是长大公路、铁路隧道火灾,往往是灾难性的。因此,基于性能化防火设计原理,对雪峰山特长公路隧道的横通道间距和车行间距进行了研究。对中等规模20 MW的火灾,按照规范建议的3 m/s的风速进行通风的情况下,先用CFD软件模拟计算火灾危险时间Tfire,然后由疏散模型中的经验公式计算人员疏散时间Tevac,比较分析不同横通道间距下人员疏散的安全性;同时为了避免隧道内车辆间的引燃,利用辐射换热原理,对车辆间的火灾蔓延性进行了分析。模拟结果为:最佳横通道间距约为290 m,最小引燃间距为6 m。考虑到建设成本的问题,建议雪峰山隧道的横通道间距改为300 m;同时,考虑到后继车辆的刹车及不同的行车速度等因素,建议特长隧道内车距最好要大于110 m;     

火灾中人群疏散延迟时间的研究

火灾中人员的疏散时间主要包括疏散前的延迟时间和在通道上的疏散时间。对疏散延迟时间的分布及其对疏散时间的影响进行了研究,利用Building Exodus软件对实际工程进行了模拟,并得出了一些重要的结论。这些结论对于修正传统疏散时间的工程计算方法、制定合理的人群管理对策具有重要的指导作用。     

建筑物火灾时人员疏散时间模型研究

在建筑物火灾中,人员安全疏散与人员的生命安全直接相关.人员能否安全疏散主要取决于疏散到安全区所用时间的长短,人员疏散时间在考虑建筑物结构和人员距离安全区的远近等环境因素的同时,还必须综合考虑处于火灾等紧急情况下人员的自然状况和人员心理及行为特征.本文在组织人员应急疏散演习测量个体疏散时间的基础上,结合影响人员疏散行为和疏散时间的相关因素,采用世界先进统计软件SPSS12 for Windows进行多元线性回归分析,建立人员疏散时间回归模型.该研究技术科学、先进,结果可信.研究结果将充实我国人员疏散心理和行为反应数据库,为建筑防火性能化设计,尤其是设计人员密集建筑提供基础数据和初步的分析.     

建筑物避难安全性能设计在台湾地区的发展

本文介绍建筑物避难安全性能设计在台湾地区的发展情况,包括楼层避难安全验证法和整栋建筑物避难安全验证法。楼层避难安全验证法分为两个阶段,第一阶段先验证起火居室人员的避难安全,第二阶段验证起火居室外整层楼人员的避难安全,并给出一个九步的验证程序和相应的计算公式。整栋建筑物避难安全验证法也分为两个阶段,第一阶段先验证各楼层人员的避难安全,第二阶段验证整栋建筑物人员避难的安全,并给出一个六步的验证程序和相应的计算公式。通过对避难安全验证法的分析,并对各自的验证程序进行了阐述,以便可以据此指导建筑物避难安全的性能设计。     

Sea otters,social justice,and ecosystem‐service perceptions in Clayoquot Sound,Canada

We sought to take a first step toward better integration of social concerns into empirical ecosystem service (ES) work. We did this by adapting cognitive anthropological techniques to study the Clayoquot Sound social‐ecological system on the Pacific coast of Canada's Vancouver Island. We used freelisting and ranking exercises to elicit how locals perceive ESs and to determine locals’ preferred food species. We analyzed these data with the freelist‐analysis software package ANTHROPAC. We considered the results in light of an ongoing trophic cascade caused by the government reintroduction of sea otters (Enhydra lutris) and their spread along the island's Pacific coast. We interviewed 67 local residents (n = 29 females, n = 38 males; n = 26 self‐identified First Nation individuals, and n = 41 non‐First Nation individuals) and 4 government managers responsible for conservation policy in the region. We found that the mental categories participants—including trained ecologists—used to think about ESs, did not match the standard academic ES typology. With reference to the latest ecological model projections for the region, we found that First Nations individuals and women were most likely to perceive the most immediate ES losses from the trophic cascade, with the most certainty. The inverse was found for men and non‐First Nations individuals, generally. This suggests that 2 historically disadvantaged groups (i.e., First Nations and women) are poised to experience the immediate impacts of the government‐initiated trophic cascade as yet another social injustice in a long line of perceived inequities. Left unaddressed, this could complicate efforts at multistakeholder ecosystem management in the region.     

People and biodiversity in the 21st century: This article belongs to Ambio’s 50th Anniversary Collection. Theme: Biodiversity conservation

Fifty years have elapsed since the first publication of Ambio. Throughout this period, fundamental changes have occurred in societal attitudes to biodiversity conservation. Ambio has published numerous papers that have aligned with these new approaches. High citations numbers suggest that Ambio papers have had a significant impact on conservation strategies. We review these publications and find that they align well with changed societal perspectives on biodiversity. Ambio papers have called for greater contributions of local and indigenous peoples and for conservation in multi-functional landscapes. The 1992 Convention on Biological Diversity built on these principles. Negotiations are now underway for a post-2020 framework for biodiversity. Ambio papers have argued for a stronger scientific basis for conservation and for the need to adapt to changing conditions and to the rich diversity of societal preferences for conservation. International processes favor simple, generalizable approaches to conservation but we call for recognition of the diversity of ecological and human conditions in which conservation occurs. There is a need to build capacity to support a diversity of conservation approaches that are adapted to changing local conditions and to the priorities of diverse human societies.     

空气污染对中老年人认知能力的影响

利用中国健康与养老追踪调查(CHARLS)数据,采用两阶段最小二乘法评估了空气污染对我国中老年人认知能力的影响及其传导路径,并进一步分析了不同类型污染物的影响差异性.研究发现:空气污染与中老年人的认知能力显著负相关,且通过一系列稳健性检验表明研究结果具有稳健性;机制分析与异质性分析显示,空气污染通过影响个人的情绪和状态、运动、社交活动、健康和记忆力来间接影响其认知能力,且空气污染对年长者、女性、有不良健康行为以及社会经济地位较低人群的认知能力负面影响更大;进一步研究发现,PM_2.5、PM₁₀、SO₂、CO具有显著的认知功能折旧效应.本文聚焦于我国空气污染和人口老龄化问题,识别了空气污染对我国居民认知能力的潜在健康影响,这在一定程度上为国家健康环境治理和实现健康老龄化提供了现实依据和政策借鉴.     

某宾馆火灾烟气扩散及疏散模拟研究

利用计算机模拟技术,对宾馆火灾烟气扩散和人员疏散过程进行了计算模拟.首先基于客房的火灾可燃物分析,设定了火灾增长功率曲线.利用大涡火灾模型,计算了火灾发生后,起火房间、疏散通道及疏散出口内的影响人员疏散的温度、有毒气体浓度以及能见度发展趋势,给出火灾条件下可用安全疏散时间.通过精细网格人员疏散模拟,分析了人员所需安全疏散时间及安全疏散行为方式,研究表明人员可以安全疏散.该方法可作为宾馆火灾安全分析参考.