Do NHTSA vehicle safety ratings affect side impact crash outcomes?

Introduction: Side impact crash injuries tend to be severe, mainly due to the effects of the mechanism of such crashes. This study addresses the relationship between side impact crash injury severities and side impact safety ratings of the passenger cars involved in such crashes. It is motivated by the lack of research on side impact safety ratings in relation to the real-world crash outcomes. Method: Analysis of Crashworthiness Data System’s (CDS) data show the head and thorax are the most common regions of impact of severe injuries, while the neck is the least. Irrespective of body regions, higher-rated vehicles were found to provide better occupant protection to both younger and older driver age groups. Assessment based on injury severity score (ISS) indicates that higher-rated vehicles have an overall lower average ISS compared to lower-rated vehicles. Results: Ultimately, this study shows that vehicles rated with National Highway Traffic Safety Administration’s (NHTSA) new criteria had lower average ISS compared to vehicles rated under the old criteria. The 2011 NHTSA side impact rating criteria being relatively new, it has very few crashes to draw meaningful statistically significant conclusions. However, this paper establishes the fact that vehicles with higher star ratings (under experimental conditions) indeed offer increased occupant protection in the field conditions. Practical applications: Previous studies have found that safety was given priority while buying new vehicles. However, people associated vehicle safety with technologies and specific safety features rather than the vehicle’s crash test results or ratings (Koppel, Charlton, Fildes, & Fitzharris, 2008). The results from this study provide a point of reference for safety advocates to educate the drivers about the importance of considering vehicle safety ratings during a vehicle purchase.     

含聚油泥处理工艺参数优化及交互作用分析

采用自制的油泥分离剂通过热化学分离法处理聚驱油田现场产生的含聚油泥。采用正交实验得到的最佳工艺参数为:剂泥比2.0 m L/g,反应温度80℃,反应时间30 min,搅拌转速500 r/min,在此工艺条件下原油回收率为92.08%。利用支持向量机运算法(SVM)建立模型,分析了各工艺参数之间的交互作用,得出优化后的含聚油泥处理工艺参数为:剂泥比2.5 m L/g,反应温度80℃,反应时间34 min,搅拌转速530 r/min,理论上的最高原油回收率为94.76%。对于模型优选出的工艺参数进行了5组验证实验,平均原油回收率达94.50%。采用优选工艺参数处理3种不同来源的含聚油泥,原油回收率均高于90%。     

山区农村居民点空间分布特征与空间重构研究

梵净山地区地属喀斯特山区,其核心区为国家级自然保护区,村庄规划布局的制约因素较多。为实现农村居民点的空间优化,综合评价了农村居民点的空间位置、自然资源和区位条件对农村居民点分布的影响,利用主成分分析法综合各影响指标,求出农村居民点规模值,在此基础上通过基于断裂点的加权Voronoi图分割其作用范围,结合"居住场势"分类,找出需要搬迁的农村居民点。结果表明:1研究区共有农村居民点23 046个,面积14 342.78 hm~2,居民点多沿道路支线和河流分布于山间河谷地带,布局散乱。2区域内有零星居民点7 871个,面积为2 641.75 hm~2,占18.42%;需保留居民点10 288个,面积为5 680.46 hm~2,占39.6%;中心居民点4 887个,面积为6 020.57 hm~2,占41.98%。3空间布局优化后的农村居民点共15 175个,总面积不变,主要应将西部和梵净山保护区内的零散聚落向东部水源充沛、交通发达的集镇地区搬迁。研究成果可为梵净山地区新农村规划的科学编制提供理论参考。     

浙江省碳排放时空格局及影响因素研究

利用2005~2010年浙江省各县市区的社会经济数据和能耗数据,测算了各县市区的碳排放总量、人均碳排放量和地均碳排放量,采用空间自相关方法揭示了县域尺度下相邻县市区碳排放指标的空间关联性,运用地理加权回归模型定量描述了各县市区碳排放总量影响因素的空间异质性。研究结果表明:(1)研究期内,浙江省的碳排放总量从30 486万t增加到49 559万t。人均碳排放量和地均碳排放量也均呈增长趋势,且空间差异显著。(2)各县市区碳排放总量、人均碳排放量和地均碳排放量均存在较强的空间自相关性,总体上浙北浙东呈高高集聚,浙西南呈低低集聚。(3)人口和投资是影响碳排放总量的重要因素,且存在空间异质性。投资对浙西南碳排放的影响逐渐增大。     

基于地理加权回归克里金的降水数据融合及其在水文预报中的应用

地理加权回归克里金(GWRK)是在地理加权回归(GWR)基础上扩展得到的一种既能考虑回归关系的空间非平稳性又能考虑回归变量空间自相关性的降水数据融合方法。以赣江流域为例,在评价TRMM卫星数据精度的基础上,分别以GWRK和GWR方法构建了站点-卫星降水数据融合模型,然后采用降水融合数据驱动GR4J水文模型进行水文预报。根据站点尺度降水融合数据精度及水文预报表现,对GWRK和GWR构建的降水融合模型效果进行评价,结果表明:较之GWR方法,GWRK方法能较明显的提高降水融合数据在站点尺度上的精度,但是由于输入到水文模型中的数据为面降水数据,受空间均化的影响,对水文预报精度的提高不如对站点尺度降水融合数据精度的提高明显。     

基于Delaunay三角网和地理加权回归的降水空间异常探测方法研究

针对目前已有的降水资料质量控制方法适应性差,降水数据难以模拟局地降水规律的问题。以湖南省为实验区域,利用1985~2014年夏季降水观测数据,定义局部地理空间内降水量发生显著偏离的气象站点为异常,发展了一种结合Delaunay三角网和地理加权回归的降水空间异常探测方法。该方法通过构建不规则三角网来获取各个区域之间稳定合理的地理邻近关系,根据空间邻近关系获取自适应回归带宽,并纳入地理加权回归模型进行计算,最后根据回归残差项的统计分布性质开展空间异常度量与分析。实验表明该方法能有效检测出降水空间异常,可应用于降水数据二次处理时的质量控制阶段,有助于进一步探索局部地理空间内的降水规律。     

指数加权移动平均控制图在实验室中的应用及与其他质控图比较

阐述了指数加权移动平均(EWMA)控制图在环境分析实验室中的应用,并与休哈特控制图和Westgard多规则对于不同偏移量的ARL值作了比较.结果表明,EWMA控制图在检验不准确度,尤其在微小偏移上的优势值得推广.     

An inexact optimization approach for river water-quality management

A previously developed fuzzy waste load allocation model (FWLAM) for a river system is extended to address uncertainty involved in fixing the membership functions for the fuzzy goals of the pollution control agency (PCA) and the dischargers using the concept of grey systems. The model provides flexibility for the PCA and the dischargers to specify their goals independently, as the parameters for membership functions are considered as interval grey numbers instead of deterministic real numbers. An inexact or a grey fuzzy optimization model is developed in a multiobjective framework, to maximize the width of the interval valued fractional removal levels for providing latitude in decision-making and to minimize the width of the goal fulfillment level for reducing the system uncertainty. The concept of an acceptability index for order relation between two partially or fully overlapping intervals is used to get a deterministic equivalent of the grey fuzzy optimization model developed. The improvement of the optimal solutions over a previously developed grey fuzzy waste load allocation model (GFWLAM) is shown through an application to a hypothetical river system. The fuzzy multiobjective optimization and fuzzy goal programming techniques are used to solve the deterministic equivalent of the GFWLAM.     

基于GIS的区域环境噪声分析与评价

噪声污染具有复杂的空间分布特征,传统的噪声评价方法难以达到准确、直观的效果。噪声分布的空间特性和GIS强大的空间数据处理和分析功能及可视化图像操作界面,使得GIS在处理与空间位置有关的环境噪声问题方面体现出巨大优势。以大学校园为例,探讨了GIS方法在区域环境噪声评价方面的应用。研究结果表明,GIS 方法评价噪声高效、准确、直观,是区域环境噪声评价理想的技术工具并具有良好的应用前景。