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531.
AbstractObjectives: Automatic emergency braking (AEB) is a proven effective countermeasure for preventing front-to-rear crashes, but it has not yet fully lived up to its estimated potential. This study identified the types of rear-end crashes in which striking vehicles with AEB are overrepresented to determine whether the system is more effective in some situations than in others, so that additional opportunities for increasing AEB effectiveness might be explored.Methods: Rear-end crash involvements were extracted from 23?U.S. states during 2009–2016 for striking passenger vehicles with and without AEB among models where the system was optional. Logistic regression was used to examine the odds that rear-end crashes with various characteristics involved a striking vehicle with AEB, controlling for driver and vehicle features.Results: Striking vehicles were significantly more likely to have AEB in crashes where the striking vehicle was turning relative to when it was moving straight (odds ratio [OR]?=?2.35; 95% confidence interval [CI], 1.76, 3.13); when the struck vehicle was turning (OR = 1.66; 95% CI, 1.25, 2.21) or changing lanes (OR = 2.05; 95% CI, 1.13, 3.72) relative to when it was slowing or stopped; when the struck vehicle was not a passenger vehicle or was a special use vehicle relative to a car (OR = 1.61; 95% CI, 1.01, 2.55); on snowy or icy roads relative to dry roads (OR = 1.83; 95% CI, 1.16, 2.86); or on roads with speed limits of 70+ mph relative to those with 40 to 45?mph speed limits (OR = 1.49; 95% CI, 1.10, 2.03). Overall, 25.3% of crashes where the striking vehicle had AEB had at least one of these overrepresented characteristics, compared with 15.9% of strikes by vehicles without AEB.Conclusions: The typical rear-end crash occurs when 2 passenger vehicles are proceeding in line, on a dry road, and at lower speeds. Because atypical crash circumstances are overrepresented among rear-end crashes by striking vehicles with AEB, it appears that the system is doing a better job of preventing the more typical crash scenario. Consumer information testing programs of AEB use a test configuration that models the typical rear-end crash type. Testing programs promoting good AEB performance in crash circumstances where vehicles with AEB are overrepresented could guide future development of AEB systems that perform well in these additional rear-end collision scenarios. 相似文献
532.
本文介绍了使用超声波和磁粉探伤技术对某大吨位铸造用桥式起重机主起升系统吊具金属结构母材及其焊缝探伤检验的一些情况,重点阐述了探伤检验部位确定的方法和依据。 相似文献
533.
我国安全培训机构分布现状分析 总被引:6,自引:3,他引:3
周刚林 《中国安全生产科学技术》2009,5(2):129-132
为了解现有安全培训机构分布状况,对当前全国3813家机构有关信息进行了统计分析。分析结果表明:安全培训机构建设已经进入了规范提高阶段,当前安全培训机构合理利用了各类资源,但四级安全培训机构定位尚不明确。建议充分发挥四级机构作用,建立安全培训机构地域分布合理的判定标准。 相似文献
534.
面对计算机行业的飞速发展,产品生产企业在不断创新技术的同时,也需要持续了解国家对产品节能认证及测试的最新标准,已满足产品节能的新要求。本文简述新旧版计算机节能认证技术规范的主要差异,运用实例比对阐述标准的使用,帮助企业更好的理解新版标准的实施。 相似文献
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根据语言测试的发展历程,指出了语言测试在外语教学过程中发挥的作用。当前高职英语测试存在学期测试与等级测试脱节、测试模式陈旧、形式单一、等级测试题型死板等问题。结合高职英语教学现状和学生素质水平,对高职英语的常规测试模式提出改革,构建了形成性评价与终结性评价相结合、重技能、寓考于乐的高职英语的新测试体系。 相似文献
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Partial stroke testing of process shutdown valves: How to determine the test coverage 总被引:1,自引:0,他引:1
Mary Ann Lundteigen Marvin Rausand 《Journal of Loss Prevention in the Process Industries》2008,21(6):579-588
Partial stroke testing (PST) has recently been introduced as a semi-automatic means to test process shutdown valves. Normally, this type of testing does not disturb the process and can detect many of the failures that traditionally have been revealed only by functional testing. The fraction of all dangerous failures that are detected by PST is called the PST coverage and is decisive for the effectiveness of the PST. So far, limited guidance on how to determine the PST coverage has been given. This paper discusses the application and limitations of PST and suggests a new procedure for how to determine the PST coverage factor. 相似文献