防提安全装置现场应用事故分析与规避措施

防提安全装置是起下钻杆中防止误操作的安全设备,但长时间未对其进行结构改进,且其在应用过程中存在操作不规范情况,从而在油田钻井过程中引起诸多问题,甚至导致一系列严重事故的发生。以某油田防提安全装置现场应用事故为例,从装置系统设计,现场操作和人为因素等方面分析出了此次事故发生的直接原因与间接原因。同时结合其他类似事故的调研分析结果,对防提安全装置提出了可行的优化与改进方案,规范了该装置操作与监督岗位的作业要求,且细化了该装置维护与故障处理的具体措施,从而做到了从多方面预防类似事故的发生。通过应用发现,防提安全装置的事故原因分析方法和规避措施可有效地防止类似故障的发生,提高油气钻采过程井口设备的安全性,其也可作为油田其他类似装置优化改进以及规范现场操作的参考。     

国内船舶碰撞事故科研产出及主题趋势挖掘

为了全面认识国内船舶碰撞研究的整体现状及趋势,基于中国知网的2000—2016年506篇船舶碰撞学位论文和1957—2016年1 620篇期刊论文,使用科学计量和知识图谱的方法进行了可视化分析。结果表明:学位论文和期刊论文的产出主要集中以大连海事大学、上海海事大学、上海交通大学以及武汉理工大学为核心形成不同的研究团队。关于船舶碰撞的学位论文主要集中在AI、船舶避碰、数值仿真等方面,期刊论文的热点主要分布在船舶避碰、碰撞事故、碰撞危险等方面。整体来看,2000年以后学位和期刊论文在研究上的趋势是相近的,都在关注AI、数值模拟方法和碰撞责任主体等方面的避碰主题,近期新兴的研究更加关注在一些船舶碰撞微观的层面。     

A Comparison of Waste Reduction Practices and the New Environmental Paradigm in Four Southern Chinese Areas

On domestic waste recycling, it was found that source separation of domestic waste in mainland China was supported by 85% of the urban population and about 11–13% of the household waste was recovered and sold by the householders for financial gains. It was also found that the lower income group tended to recover a greater portion of waste, indicating that voluntary waste recovery activities in mainland China were carried out largely due to economic reasons. Thus, the Western type of source separation program in which residents are requested to separate recyclables for the community may not be welcomed in mainland China. In Hong Kong, despite the presence of community waste recovery programs, the recovery of domestic waste is only about 6% and is therefore less than those of the mainland Chinese cities surveyed. On the choice of source separation programs, it was found that Hong Kong people ranked familiarity a more important criterion than convenience. Therefore, the collection frequency of recyclables and time and place for setting out recyclables should be as similar to those of normal waste collection as possible to attract high participation in source separation programs.     

Characteristics of rear-end crashes involving passenger vehicles with automatic emergency braking

Abstract

Objectives: 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.     

Intersection AEB implementation strategies for left turn across path crashes

Abstract

Objective: Left turn across path with traffic from the opposite direction (LTAP/OD) is the second most frequent car-to-car intersection crash type after straight crossing path (SCP) in Germany and the United States. Intersection automated emergency braking (AEB) for passenger cars can address these crashes.

This study investigates 2 implementation strategies of intersection AEB addressing LTAP/OD crashes: (1) only the turning car is equipped with an intersection AEB and (2) turning and straight-heading cars are equipped with an intersection AEB. For each strategy, the influence of a safety zone around the vehicles that should not be entered is evaluated in terms of accident avoidance, injury mitigation, and change in velocity (delta-V) of remaining accidents. Results are given as a function of market penetration.

Methods: A total of 372 LTAP/OD crashes from the time series precrash matrix (PCM), a subsample of the German In-Depth Accident Study (GIDAS), were resimulated in the PRediction of Accident Evolution by Diversification of Influence factors in COmputer simulation (PRAEDICO) simulation framework. A Kudlich-Slibar rigid-body impact model and an injury risk curve derived from GIDAS were used to predict remaining moderate to fatal (Maximum Abbreviated Injury Scale [MAIS] 2?+?F) injuries among car occupants.

Results: With a safety zone of 0.2 m, when the turning vehicle only was equipped with an intersection AEB, 59% of the crashes were avoided at a 100% market penetration. With both vehicles equipped the percentage increased to 77%. MAIS 2?+?F injured occupants were reduced by 60 and 76%, respectively. Considering both the turning and the straight-heading vehicles, the delta-V decreased strongly with market penetration in remaining left-side impacts but only slightly in remaining frontal and right-side impacts. Eliminating the safety zone substantially decreases effectiveness in all conditions.

Conclusions: Implementation strategy and safety zone definition strongly influence the real-life performance of intersection AEB. AEB should be applied not only for the turning vehicle but also for the straight-going vehicle to benefit from the full potential. Situationally appropriate safety zone definitions, in line with human hazard perception, need more attention and are a key to balance true positive and false positive performance. Remaining delta-V does not decrease broadly; hence, there is no evidence that future LTAP/OD crashes will be generally of lower severity. This highlights the need for continuous development of in-crash protection.     

Calibrating climate change policies: the causes and consequences of sustained under-reaction

We apply insights from the recent literature on disproportionate policy reactions to the case of climate change policy-making. We show when and why climate change exhibits features of a sustained under-reaction: Governments may react to concerns about climate change not through substantive change but by efforts to manage blame strategically. As long as they can avoid blame for potential negative policy outcomes policy-makers can act to deny problems, or implement only small-scale or symbolic reforms. While this pattern may change as climate change problems worsen and public recognition of the issue and what can be done about it alters, opportunities to manage blame will still exist. Governments will only revert to more substantive interventions when attempts to fatalistically frame the problem as unavoidable fail in the face of increased public visibility.     

浙江沿海台风灾害区农房防灾避险体系探讨

台风灾害是浙江省的主要自然灾害之一。根据实地考察数据与分析资料,通过对沿海现有农房防灾能力分析,指出了造成部分农房避灾能力薄弱的原因,然后从农房防御强风能力建设、农房防灾减灾保障体系、农房规划建设管理体系、农村避灾安置场所建设、农房救助体系等方面探讨了构建农房防灾避险体系所要采取的应对措施。     

Creating Pedestrian Crash Scenarios in a Driving Simulator Environment

Objective: In 2012 in the United States, pedestrian injuries accounted for 3.3% of all traffic injuries but, disproportionately, pedestrian fatalities accounted for roughly 14% of traffic-related deaths (NHTSA 2014 NHTSA. Traffic Safety Facts 2012 Pedestrians. Washington, DC: Author; 2014. DOT HS 811 888. [Google Scholar]). In many other countries, pedestrians make up more than 50% of those injured and killed in crashes. This research project examined driver response to crash-imminent situations involving pedestrians in a high-fidelity, full-motion driving simulator. This article presents a scenario development method and discusses experimental design and control issues in conducting pedestrian crash research in a simulation environment. Driving simulators offer a safe environment in which to test driver response and offer the advantage of having virtual pedestrian models that move realistically, unlike test track studies, which by nature must use pedestrian dummies on some moving track.

Methods: An analysis of pedestrian crash trajectories, speeds, roadside features, and pedestrian behavior was used to create 18 unique crash scenarios representative of the most frequent and most costly crash types. For the study reported here, we only considered scenarios where the car is traveling straight because these represent the majority of fatalities. We manipulated driver expectation of a pedestrian both by presenting intersection and mid-block crossing as well as by using features in the scene to direct the driver's visual attention toward or away from the crossing pedestrian. Three visual environments for the scenarios were used to provide a variety of roadside environments and speed: a 20–30 mph residential area, a 55 mph rural undivided highway, and a 40 mph urban area.

Results: Many variables of crash situations were considered in selecting and developing the scenarios, including vehicle and pedestrian movements; roadway and roadside features; environmental conditions; and characteristics of the pedestrian, driver, and vehicle. The driving simulator scenarios were subjected to iterative testing to adjust time to arrival triggers for the pedestrian actions. This article discusses the rationale behind creating the simulator scenarios and some of the procedural considerations for conducting this type of research.

Conclusions: Crash analyses can be used to construct test scenarios for driver behavior evaluations using driving simulators. By considering trajectories, roadway, and environmental conditions of real-world crashes, representative virtual scenarios can serve as safe test beds for advanced driver assistance systems. The results of such research can be used to inform pedestrian crash avoidance/mitigation systems by identifying driver error, driver response time, and driver response choice (i.e., steering vs. braking).     

Toxicity assessment for chlorpyrifos-contaminated soil with three di erent earthworm test methods

Earthworm toxicity tests are useful tools for terrestrial risk assessment but require a hierarchy of test designs that differ in effect levels （behavior, sublethal, lethal）. In this study, the toxicity of chlorpyrifos contaminated soil on earthworms was assessed. In addition to the acute and chronic tests, an avoidance response test was applied. Earthworms were exposed to sublethal and lethal concentration of chlorpyrifos, and evaluated for acute toxicity, growth, fecundity and avoidance response after a certain exposure period. The test methods covered all important ecological relevant endpoints （acute, chronic, behavioral）. Concentration of 78.91 mg/kg, chlorpyrifos caused significant toxic effects in all test methods, but at lower test concentrations, only significant chronic toxic effects could be observed. In present study, chlorpyrifos had adverse effect on growth and fecundity in earthworm exposed to 5 mg/kg chlorpyrifos after eight weeks. The avoidance response test, however, showed significant repellent effects at concentration of 40 mg/kg chlorpyrifos. For chlorpyrifos, concentration affecting avoidance response was far greater than growth and fecundity, it seemed likely that earthworms were not able to escape from pesticide-contaminated soil into the clean soil in field and hence were exposed continuously to elevated concentrations of pesticides.     

Kin recognition in rainbowfish (Melanotaenia eachamensis): sex, sibs and shoaling

Living with relatives can be beneficial to individuals via the evolution of kin-directed altruism, but this is tempered by the increased risk of inbreeding. Therefore, in social species, the ability to recognise relatives can be highly advantageous. This study focuses on kin discrimination in the Lake Eacham rainbowfish, Melanotaenia eachamensis, an endangered freshwater species from north-east Queensland, Australia. First, I examined kin recognition abilities when a combination of both chemical and visual recognition cues was available. When given a choice of shoaling with same-sex groups, females spent significantly longer with full-sibs rather than half-sibs, full-sibs rather than non-relatives and half-sibs rather than non-relatives. Males spent significantly longer shoaling with full-brothers versus half-brothers, but showed no other shoalmate preferences. Second, in the presence of only chemical cues, females did not discriminate among groups of different levels of relatedness, but males showed a non-significant tendency to associate with full-sibs rather than non-relatives. Male shoaling behaviour seemed to be more influenced by factors other than relatedness, e.g. intra-sexual competition. Finally, I found that the shoaling preferences of females changed when exposed to groups of males. Females preferred to associate with non-relatives rather than half-brothers and non-relatives rather than full-brothers. There was no significant difference in the time spent with half-brothers versus full-brothers. Taken together, my results suggest that females have very good kin recognition abilities. They prefer to shoal with female relatives but avoid male relatives, and so are able to balance the benefits of nepotism and the costs of incest. Received: 2 May 2000 / Revised: 26 July 2000 / Accepted: 30 July 2000