Understanding the efficiency of social media based crisis communication during hurricane Sandy

Rapid communication during extreme events is one of the critical aspects of successful disaster management strategies. Due to their ubiquitous nature, social media platforms are expected to offer a unique opportunity for crisis communication. In this study, about 52.5 million tweets related to hurricane Sandy posted by 13.75 million users are analyzed to assess the effectiveness of social media communication during disasters and identify the contributing factors leading to effective crisis communication strategies. Efficiency of a social media user is defined as the ratio of attention gained over the number of tweets posted. A model is developed to identify more efficient users based on several relevant features. Results indicate that during a disaster event, only few social media users become highly efficient in gaining attention. In addition, efficiency does not depend on the frequency of tweeting activity only; instead it depends on the number of followers and friends, user category, bot score (controlled by a human or a machine), and activity patterns (predictability of activity frequency). Since the proposed efficiency metric is easy to evaluate, it can potentially detect effective social media users in real time to communicate information and awareness to vulnerable communities during a disaster.     

Efficacy and authority of the message sender during emergency evacuations: a mixed methods study

To understand why coastal residents do not always evacuate before storms, a pair of studies analyzed evacuation decision-making among residents of Long Beach, NY and surrounding municipalities on Long Island, NY via a mixed methodology approach. First, residents who lived in Long Beach, NY during ‘Superstorm’ (hurricane turned post-tropical cyclone) Sandy in October 2012 were interviewed about their evacuation decision. Second, 34 pre-storm messages were developed and administered to residents of the same area: faced with a hypothetical oncoming hurricane, respondents indicated after each message whether they would evacuate. In the interviews, residents spoke more about friends and family than traditional authority figures; survey results, however, imply that residents are more likely to evacuate given messages from traditional authority figures. This can be resolved with the Elaboration Likelihood Model of persuasion, which suggests that motivation and emotional state influence information processing. Implications for actual emergency message formation are discussed.     

高层建筑逃生自救安全措施分析

随着越来越多的高层建筑的出现,消防安全隐患日益增多。本文通过分析目前国内高层建筑的火灾特点,提出了具有现实性和可操作性的高层建筑火灾逃生自救措施,并对进一步加强高层建筑的消防工作提出建议。     

被“标识”的国家:撤侨话语中的国家认同与家国想象

"想象的共同体"确立了论述国家的话语方式,书写(论述)国家的行动本身,就是通过想象(叙事)来弥补在多元复杂的社会力量中所遗失的国家"同一性",从而将宏大的民族国家叙事和细碎而弥散的日常生活建立起勾连。本文从想象国家的理论脉络出发,以新世纪以来《人民日报》对海外撤侨行动的报道为研究对象,对报道中所呈现的"国家"话语进行文本分析。研究发现,建构主义范式与原生主义范式共同作用于国家想象的生成与可见,从而"标识"国家。由此,撤侨话语成为一种展现国家力量与国家意识的权力书写,通过英雄原型叙事、建构集体记忆的话语互文、塑造"家国一体"的概念隐喻以及话语互动,实现国家情感的表达与国家认同的凝聚。     

基于数值模拟的阶梯水流中行人安全撤离研究(英文)

目的:研究不同形式阶梯水流中被困人员的安全撤离,为地下空间水侵灾害脆弱性评价及防灾避灾提供参考。方法:根据试验结果和数值模型的相关理论构建数值模型,验证数值模拟阶梯水流流场的可靠性和合理性,并基于数值模型的灵活性和可变性,模拟休息平台、阶梯坡度和阶梯形态对水流流场的影响,据此对有无休息平台、不同阶梯坡度和不同阶梯形态下阶梯水流流态、流速分布以及对被困人员的安全撤离的影响进行深入分析。结论:中间休息平台的存在增加了被困人员撤离的风险;阶梯坡度对阶梯上水流的水力特性影响很小;L型阶梯中间休息平台有利于减小平台下游撤离风险,被困人员可以优先选择L型阶梯或者不含休息平台的直线型阶梯撤离。