This study aims at identifying crash-influencing factors by facility type of Nagoya Urban Expressway, considering the interaction of geometry, traffic flow, and ambient conditions. Crash rate （CR） model is firstly d...This study aims at identifying crash-influencing factors by facility type of Nagoya Urban Expressway, considering the interaction of geometry, traffic flow, and ambient conditions. Crash rate （CR） model is firstly developed separately at four facility types： basic, merge, and diverge segments and sharp curve. Traffic flows are thereby categorized, and based on the traffic categories, the significances of factors affecting crashes are analyzed by principal component analysis. The results reveal that, the CR at merge segment is significantly higher than those at basic and diverge segments in uncongested flow, while the value is not significantly different at the three facility types in congested flow. In both un- and congested flows, sharp curve has the worst safety performance in view of its highest CR. Regarding influencing factors, geometric design and traffic flow are most significant in un- and congested flows, respectively. As mainline flow increases, the effect of merging ratio affecting crash is on the rise at basic and merge segments as opposed to the decreasing significance of diverging ratio at diverge segment. Mean- while, longer acceleration and deceleration lanes are adverse to safety in uncongested flow, while shorter acceleration and deceleration lanes are adverse in congested flow. Due to its special geometric design, crashes at sharp curve are highly associated with the large centrifugal force and heavy restricted visibility.展开更多
Obnoxious facilities are those crucial to human living, yet antagonistic to the public or environment. However, the interactions between obnoxious facilities and their clients have been less frequently investigated. A...Obnoxious facilities are those crucial to human living, yet antagonistic to the public or environment. However, the interactions between obnoxious facilities and their clients have been less frequently investigated. A state-of-the-art model for this problem involves numerous 0 - 1 variables, rendering it difficult to solve. This study aims at removing most of these 0 - 1 variables to enhanced model efficiency. A compact model is presented in this study, with the equivalence between the new and original models proved. Additionally, numerical tests were conducted to show that the proposed compact model is more efficient than the original one.展开更多
Philippine President Corazon Aquino announced on October 2 she will give the United States no more than three years to leave Subic Bay naval base, abandoning plans for a referendum to save the facility.
机场航站楼属于大型公共建筑,一旦发生火灾易造成烟气聚集且导致人员疏散困难,传统消防设施难以满足此类建筑的消防需求。本文针对耦合消防设施的演化机理进行研究,首先建立航站楼候机厅建筑信息模型(BIM,building information modelin...机场航站楼属于大型公共建筑,一旦发生火灾易造成烟气聚集且导致人员疏散困难,传统消防设施难以满足此类建筑的消防需求。本文针对耦合消防设施的演化机理进行研究,首先建立航站楼候机厅建筑信息模型(BIM,building information modeling),然后通过火灾动态模拟器(FDS,fire dynamics simulator)对航站楼候机厅进行不同场景下的火灾模拟,进而得到不同场景、不同区域下的喷淋、烟气层高度、能见度、热释放速率等指标数据,并根据其变化过程分析火灾演化机理。研究结果表明,针对航站楼这种具有特殊性的公共建筑,耦合消防设施和消防设施未启动情况下火灾演化机理具有显著差异。同时,模拟结果可以为航站楼消防设计的优化和应急疏散方案的制定提供思路。展开更多
基金support of Nagoya Expressway Public Corporation for the data provision
文摘This study aims at identifying crash-influencing factors by facility type of Nagoya Urban Expressway, considering the interaction of geometry, traffic flow, and ambient conditions. Crash rate （CR） model is firstly developed separately at four facility types： basic, merge, and diverge segments and sharp curve. Traffic flows are thereby categorized, and based on the traffic categories, the significances of factors affecting crashes are analyzed by principal component analysis. The results reveal that, the CR at merge segment is significantly higher than those at basic and diverge segments in uncongested flow, while the value is not significantly different at the three facility types in congested flow. In both un- and congested flows, sharp curve has the worst safety performance in view of its highest CR. Regarding influencing factors, geometric design and traffic flow are most significant in un- and congested flows, respectively. As mainline flow increases, the effect of merging ratio affecting crash is on the rise at basic and merge segments as opposed to the decreasing significance of diverging ratio at diverge segment. Mean- while, longer acceleration and deceleration lanes are adverse to safety in uncongested flow, while shorter acceleration and deceleration lanes are adverse in congested flow. Due to its special geometric design, crashes at sharp curve are highly associated with the large centrifugal force and heavy restricted visibility.
文摘Obnoxious facilities are those crucial to human living, yet antagonistic to the public or environment. However, the interactions between obnoxious facilities and their clients have been less frequently investigated. A state-of-the-art model for this problem involves numerous 0 - 1 variables, rendering it difficult to solve. This study aims at removing most of these 0 - 1 variables to enhanced model efficiency. A compact model is presented in this study, with the equivalence between the new and original models proved. Additionally, numerical tests were conducted to show that the proposed compact model is more efficient than the original one.
文摘Philippine President Corazon Aquino announced on October 2 she will give the United States no more than three years to leave Subic Bay naval base, abandoning plans for a referendum to save the facility.
文摘机场航站楼属于大型公共建筑,一旦发生火灾易造成烟气聚集且导致人员疏散困难,传统消防设施难以满足此类建筑的消防需求。本文针对耦合消防设施的演化机理进行研究,首先建立航站楼候机厅建筑信息模型(BIM,building information modeling),然后通过火灾动态模拟器(FDS,fire dynamics simulator)对航站楼候机厅进行不同场景下的火灾模拟,进而得到不同场景、不同区域下的喷淋、烟气层高度、能见度、热释放速率等指标数据,并根据其变化过程分析火灾演化机理。研究结果表明,针对航站楼这种具有特殊性的公共建筑,耦合消防设施和消防设施未启动情况下火灾演化机理具有显著差异。同时,模拟结果可以为航站楼消防设计的优化和应急疏散方案的制定提供思路。
