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11.
Driver visual distraction is known to increase the likelihood of being involved in a crash, especially for long glances inside the vehicle. The detrimental impact of these in-vehicle glances may carry over and disrupt the ongoing processing of information after the driver glances back up on the road. This study explored the effect of different types of visual tasks inside the vehicle on the top-down processes that guide the detection and monitoring of road hazards after the driver glances back towards the road. Using a driving simulator, 56 participants were monitored with an eye tracking system while they navigated various hazardous scenarios in one of four experimental conditions. In all conditions, a potential hazard was visible 4–5 s before the driver could strike the potential hazard were it to materialize. All interruptions were exactly two seconds in length. After the interruption the potential hazard again became visible for about a half-second after which the driver passed by the hazard. The nature of the in-vehicle visual interruption presented to the participants was varied across conditions: (1) Visual interruptions comprised of spatial, driving unrelated, tasks; (2) visual interruptions comprised of non-spatial, driving unrelated, tasks; (3) visual interruptions with no tasks added; and (4) no visual interruptions. In the first three conditions drivers glancing on the forward roadway was momentarily interrupted (either with or without a task) just after the potential hazard first became visible by the occurrence of an in-vehicle task lasting two seconds. In the last condition (no interruptions) the driver could not see the potential hazard after it just became visible because of obstructions in the built or natural environment. The obstruction (like the interruption) lasted for two seconds. In other words, across all conditions the hazard was visible, then became invisible, and finally became visible again. Importantly, the results show that the presence of an interruption (as opposed to an obstruction) negatively impacted drivers’ ability to anticipate the potential hazard. Moreover, the various types of interruptions had differential effects on hazard detection. The implications of this study for the design of in-vehicle displays are discussed. 相似文献
12.
The influence of seven practical curing regimes on restrained shrinkage cracking of bonded concrete overlays was investigated. The influence of the curing regimes on the individual material properties governing restrained shrinkage cracking and on the age at cracking and crack area of ring tests and composite overlay–substrate specimens was investigated for three laboratory-made mixes of differing strengths and one commercial repair mortar. The results of the experimental testing showed that curing influences all of the material properties governing restrained shrinkage cracking. Prolonged or more effective curing was shown to either delay or reduce the rate of shrinkage respectively (dependent on the curing method), increase the tensile strength and elastic modulus, and decrease the tensile relaxation. In general, prolonged or more effective curing was shown to have a positive influence on restrained shrinkage cracking by increasing the age and net age at cracking. 相似文献
13.
In order to explore the immersed tunnel foundation treated by sand-flow method, modeling principles for the full-scale model test of sand flow were put forward. In addition, a sand-flow test model was built, which consisted of model system, equipment system and measurement system. The situation of sand-deposit expanding and the water pressure in the foundation trench were evaluated through the model test. The results show that a semi-closed space was formed between the model board and the expanding sand deposit, which made the water pressure in it rising with little range of volatility. The sand deposit gradually became non-circular truncated cone which shaped with its expanding radius, and the difference of the water pressure increased at each direction. The water pressure in crater had a linear increase with the sand-deposit radius, with a maximal value of 0.015 2 MPa. The volatility of the water pressure under the tunnel board and the water pressure value in the crater could be used as bases of construction control. 相似文献
14.
现代工科院校桥梁工程课程多元化教学方式探讨 总被引:3,自引:3,他引:0
桥梁工程课程是工科院校土木工程专业道桥方向一门重要的专业课程.文章在探讨该课程的特点、教学现状、影响因素的基础上,结合现代化教学手段和丰富的网络资源,提出了扩展式、参与式、讨论式等多元化的教学方式,以激发学生学习的积极性和参与性,提高桥梁工程课程教学效果. 相似文献
15.
为了揭示浇筑式沥青混合料超热老化机理,采用傅里叶红外光谱法(FTIR)和热失重法(TG)实时追踪扫描了微观尺度下浇筑式沥青不同超热温度下分子基团以及轻质组分的变化规律,分析了超热温度下挥发和氧化对改性沥青老化的影响进程.结果表明:在超热温度下,挥发对浇筑式沥青混合料老化所起的作用明显,并且一直贯穿整个超热老化过程,而氧气浓度决定了氧化在其整个老化过程中的作用时间,在高氧气浓度下,氧化主要发生在老化前期,而老化后期轻质组分的挥发起主导作用. 相似文献
16.
对相同混凝土配合比的5组混凝土柱(1组全黏结SMA(形状记忆合金)驱动混凝土柱,1组半黏结SMA驱动混凝土柱,1组无黏结SMA驱动混凝土柱,1组全黏结SMA未驱动混凝土柱,1组素混凝土柱)进行了轴压试验研究,比较分析了5组混凝土柱的纵向应变、横向应变、极限荷载、裂现荷载等轴压性能.结果表明:SMA混凝土柱抗裂性能大小顺序为:半黏结SMA驱动混凝土柱>全黏结SMA驱动混凝土柱>无黏结SMA驱动混凝土柱>全黏结SMA未驱动混凝土柱;SMA混凝土柱的极限荷载大致相等,并且都比素混凝土柱大;SMA螺旋箍筋与混凝土半黏结将有利于SMA螺旋箍筋对混凝土柱施加预应力;可利用SMA螺旋箍筋对混凝土柱施加较大的预应力,实现对混凝土柱的变形控制. 相似文献
17.
采用增黏树脂制备树脂改性乳化沥青,分析了改性乳化沥青蒸发残留物老化前后的常规性能、储存稳定性和黏结性能,并采用荧光显微镜(FM)和傅里叶红外光谱仪(FTIR)对改性乳化沥青的相结构和改性机理进行分析.结果表明:掺加树脂能提高乳化沥青老化前后的软化点,降低针入度和延度,其中延度衰减明显;当增黏树脂掺量为25%时,改性乳化沥青在25,45℃下的拉拔强度分别为1.41,0.73MPa,具有优异的黏结性能;当增黏树脂掺量为20%时,改性乳化沥青5d储存稳定性为37.19%,不满足规范要求;当增黏树脂掺量为15%时,树脂与沥青达到饱和状态,形成致密的交联网状结构.因此,增黏树脂的最佳掺量为15%. 相似文献
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