基于事件提取和改进MMHC的航空旅客运输事故征候贝叶斯网络建模*

为表征航空旅客运输事故征候演化机理,提出事故征候贝叶斯网络的建模方法。基于事故征候中致因事件、结果事件及分类标准的定义,以7 265起事故征候案例为样本,利用事件提取算法,识别事故征候叙述文本中的致因事件,利用改进的最大最小爬山算法实现网络建模;依据事件提取的测试集验证与结构学习的交叉验证,检验建模算法的准确性与有效性;基于证据敏感性指标,识别关键致因事件。结果表明:航空旅客运输事故征候贝叶斯网络模型包含94个节点和247条有向弧。空降冲突、严重设备故障、机组成员疾病及火灾烟雾是模型中高风险关联的致因事件,在安全监管过程中消除或减弱关键致因事件的发生能有效控制系统风险。     

基于ABAQUS二次开发的头盔防碰撞仿真系统及应用

目前国内的航空头盔设计仍依赖于经验设计,设计出来的头盔冗余较大,且需要大量的实验进行验证,研制周期长,效率低。针对这些问题,笔者基于ABAQUS平台,并针对航空头盔的特殊性进行二次开发,得到了一款能够进行防碰撞仿真的系统。应用该系统,仿真了3种不同规格的头盔,3种不同装配误差的泡沫硬衬垫共计6种模型的碰撞结果。仿真结果对头盔的设计有一定的指导价值。     

Ride-hailing with kids: Who’s got their back?

Introduction: As transportation network companies (TNC) are on the rise, assessing the safety of children traveling in these vehicles is imperative. For this reason, this study developed and adopted a scoring system to assess states’ safety standards for children traveling in TNC vehicles. Methods: The scoring was based on two parameters pertaining to child car seat laws for TNCs: clarity and stringency. For each parameter, three criteria that could impact child safety in TNC vehicles were formulated. If a state met a certain criterion it got 1 point and 0 otherwise. The authors gathered all the necessary information by reviewing state statutes in Nexus Uni, a legal research database. These reviews took place between December 2019 and October 2020, and this study evaluated state laws in effect on October 28, 2020. Results: During this assessment, the authors observed a lack of clarity in state child car seat laws, which could compromise safety of children traveling in TNC vehicles. For clarity of laws, Georgia and Indiana received the highest scores (3 out of 3 points), while 16 states scored only 1 point, which was the lowest score in this category. In terms of stringency of laws, Pennsylvania received the highest score (3 out of 3 points), while Indiana scored the least (0 points). Conclusions: Besides one state (Oregon), all other states defined TNCs in their state laws. All states except for Indiana and Washington required child car seats in TNC vehicles. The responsibility for child car seat use was clearly defined in 35 states. The fine for child car seat violation was $50 or more in 28 states. Practical Application: This study will help TNCs, policymakers, and stakeholders identify states that need to improve their standards for child safety in TNC vehicles, and comprehensively address the issue.     

中国环保企业竞争力评价指标体系研究及其实证应用

本研究在传统企业竞争力评价理论方法的基础上,结合环保产业发展特点,在评价体系内创新性地加入环保特色指标项,并通过层次分析法对指标权重的设定形成完整的评价指标体系。基于评价指标体系,本文以54家环保上市企业为例开展实证分析,有效验证了指标体系的合理性。结合各板块内企业竞争力分析结果,进一步开展中国环保子行业发展状况的研究,对环保行业整体及各子行业的发展特点和现状进行了深入解析。     

森林航空消防风险与作战方案的综合模糊评估

为了系统研究森林航空消防中突出而复杂的安全问题,提出1种运用危险性分析法、德尔菲法、层次分析法、模糊综合评价法的复合性方法,进行森林航空消防风险分类辨识、指标体系构建与重要度评价,对给定任务场景下的拟定作战方案进行模糊综合评估,分析识别作战方案中的薄弱环节,并有针对性地提出改进优化的策略和建议。将该方法应用于某案例得到相应的评估建议：作战方案中需要改进优化的方面依次为飞机因素、飞行员因素、管理因素,其中飞机失速速度、零件耐温极限、生理状态、净空条件是要着重核查并优化的关键性指标。研究结果表明：该方法可为森林航空消防安全评估和作战方案辅助决策提供参考和支撑,具有一定的应用价值。     

民航重要信息数据应急灾备体系建设思考

为保障民航重要信息数据资源的稳定安全,本文通过分析民航数据应急体系建设的必要性,构建民航重要数据应急灾备体系的基本原则,提出民航应急灾备体系管理流程建设和跨地域灾备中心布局建议,可为民航重要业务系统灾备体系规划提供重要参考。