The safety performance of connected vehicles on slippery horizontal curves through enhancing truck drivers’ situational awareness: A driving simulator experiment

Although drivers can adequately adjust their operating speed according to the road curvature, they show a lack of recognition regarding the pavement friction conditions. In this regard, inappropriate speed selection on Horizontal Curves (HCs) with reduced surface friction can lead to a remarkable rate of run-off-road, sideswipe, head-on, and rollover crashes, especially on rural highways. Aligned with the Connected Vehicle (CV) Pilot Program on Interstate-80 in Wyoming, this study scrutinizes how CV advisory/warning messages can enhance traffic safety on slippery HCs. To this aim, a roadway consists of two HCs with regular and slippery pavement conditions was designed in a high-fidelity driving simulator experiment. A total of 24 professional truck drivers were recruited to drive the simulated roadway under CV and non-CV environments. In the CV scenario, drivers were informed about the pavement conditions and the advisory speeds before entering HCs. In contrast, no messages were given to non-CV drivers. Truck drivers' behaviors in both scenarios were quantified using four Kinematic-based Surrogate Measures of Safety (K-SMoS), including deviation from the pathway, instantaneous acceleration, lateral speed, and steering angle. CVs’ trajectories were statistically compared to non-CVs in terms of the central tendency and dispersion using the Wilcoxon Signed-Rank Test (WSRT) and Median Absolute Deviation (MAD), respectively. The results of WSRT depicted, under the effect of CV advisory/warning messages and throughout the slippery HC, the central tendency of four K-SMoS could be shifted toward zero by 23% up to 99%. This shifting is associated with a significant safety enhancement that potentially can reduce the likelihood of curve-related crashes on slippery HCs. It was revealed that the variation in drivers’ behavior on the slippery HC could be minimized in the CV environment, where 54% up to 95% reduction in the dispersions of four K-SMoS were observed, leading to more certainty in drivers’ behavior.     

Ab initio pseudopotential studies on an Al Σ = 9 grain boundary: Effects of Na and Ca impurities

The electronic properties of an Al = 9 tilt grain boundary with segregated Na and Ca impurity atoms have been calculated by a first-principles pseudopotential method. The results show that the boundary expands and the charge density decreases significantly over the whole boundary by the segregation of Na and Ca, and there are no stronger bonds than those associated with metallic bonding in the boundary even with the impurities. It is concluded that the embrittlement promotion mechanism by Na or Ca segregation in the Al boundaries is one kind of 'decohesion model'.     

英国“代孕”合法化二十年历史回顾

在英国,代孕人工生殖是合法的医疗手段。《布雷热报告》等调查报告对英国代孕立法产生了深远影响。为实现生殖自由、子女利益和社会秩序的平衡,英国拟制定一部专门的《代孕法》。     

High-pressure electrical resistivity behaviour of nanocrystalline perovskite (La,Sr)(Mn,Fe)O3

We report here the electrical resistivity of nanocrystalline perovskite-structured La–Sr manganites as a function of pressures up to 8?GPa, at room temperature. The nanocrystalline perovskite manganites were prepared by the sol–gel technique and found to have crystallite sizes of 12–18?nm. The pressure dependence of the electrical resistivity shows a first-order phase transition at 0.66(2)?GPa and a subtle phase transition between 3.5 and 3.8?GPa. The first-order transition at 0.66?GPa can be related to the transition from localized-electron to band magnetism.     

Social Surrogacy and Adjustment: Exploring the Correlates of Having a “Social Helper” for Shy and Non-Shy Young Adolescents

A social surrogate is an individual who offers help and comfort in social situations or makes social events more exciting. In this study of 157 young adolescents (55% female; M_age = 13.84 years, SD = 0.75 years), the authors examined whether the linear and curvilinear associations between self-reported social surrogate use and adjustment outcomes (social problems, loneliness, anxiety symptoms, depressive symptoms) varied as a function of shyness and gender, after accounting for the effects of positive friendship quality. Regression analyses revealed that low and high levels of social surrogate use were related to greater social problems for all adolescents. In addition, shyness emerged as a moderator for several curvilinear effects. Specifically, results indicated that (a) high levels of social surrogate use were associated with greater anxiety for adolescents high in shyness; and (b) low levels of social surrogate use were associated with greater depressive symptoms for adolescents low in shyness. Findings highlight the developmental importance of specific types of relationship experiences during early adolescence and point to different implications of social surrogate use for shy and non-shy young adolescents.     

Residual Normality Assumption and the Estimation of Multiple Membership Random Effects Models

While conventional hierarchical linear modeling is applicable to purely hierarchical data, a multiple membership random effects model (MMrem) is appropriate for nonpurely nested data wherein some lower-level units manifest mobility across higher-level units. Although a few recent studies have investigated the influence of cluster-level residual nonnormality on hierarchical linear modeling estimation for purely hierarchical data, no research has examined the statistical performance of an MMrem given residual non-normality. The purpose of the present study was to extend prior research on the influence of residual non-normality from purely nested data structures to multiple membership data structures. Employing a Monte Carlo simulation study, this research inquiry examined two-level MMrem parameter estimate biases and inferential errors. Simulation factors included the level-two residual distribution, sample sizes, intracluster correlation coefficient, and mobility rate. Results showed that estimates of fixed effect parameters and the level-one variance component were robust to level-two residual non-normality. The level-two variance component, however, was sensitive to level-two residual non-normality and sample size. Coverage rates of the 95% credible intervals deviated from the nominal value assumed when level-two residuals were non-normal. These findings can be useful in the application of an MMrem to account for the contextual effects of multiple higher-level units.     

自闭症儿童能否痊愈?——来自谱系个体“最佳结果”及剩余缺陷研究的证据分析

自闭症谱系障碍预后效果不佳, 通常被认为是一种伴随终生的疾病。不过随着研究的拓展和深入, 部分早期被诊断为自闭症的儿童, 随着年龄增长和相关干预措施的介入, 其认知、适应性等方面均可达到正常发展水平, 并且不再符合自闭症的诊断标准, 即达到了“最佳结果”。但多数个体仍然存在不同程度的剩余缺陷。本文以自闭症预后结果评定和“最佳结果”定义演变为切入点, 分析“最佳结果”个体剩余缺陷的具体表现, 并梳理此类群体的个体特征与结果预测因素, 以期能为自闭症个体的系统干预提供有效依据。     

A survey of residual analysis and a new test of residual trend

A survey of residual analysis in behavior‐analytic research reveals that existing methods are problematic in one way or another. A new test for residual trends is proposed that avoids the problematic features of the existing methods. It entails fitting cubic polynomials to sets of residuals and comparing their effect sizes to those that would be expected if the sets of residuals were random. To this end, sampling distributions of effect sizes for fits of a cubic polynomial to random data were obtained by generating sets of random standardized residuals of various sizes, n. A cubic polynomial was then fitted to each set of residuals and its effect size was calculated. This yielded a sampling distribution of effect sizes for each n. To test for a residual trend in experimental data, the median effect size of cubic‐polynomial fits to sets of experimental residuals can be compared to the median of the corresponding sampling distribution of effect sizes for random residuals using a sign test. An example from the literature, which entailed comparing mathematical and computational models of continuous choice, is used to illustrate the utility of the test.     

Residual Geriatric Depression Symptoms: A Place for Psychotherapy

Geriatric depression is a relatively commonly occurring mental disorder. A subpopulation of depressed older adults are those who have engaged in or completed pharmacotherapy, yet continue to experience depressive symptoms. We review the prevalence, psychosocial effects, and treatment of residual symptoms of depression in older adults. Data from previous studies conducted by our group are presented to support our contention that residual symptoms of geriatric depression are treatable through psychosocial means.     

防治血管剩留风险的决策探讨

针对冠心病和（或）2型糖尿病患者,已有许多有效的防治措施。然而,尽管接受了当前的标准治疗,这类患者仍会反复发生许多大血管和微血管事件,这种现象称之为血管剩留风险。有许多因素影响血管剩留风险的存在,其中最为重要的是致动脉粥样硬化性血脂异常。因此,采取积极的全面干预措施如改善生活方式、联合降脂以改善所有的脂质异常指标,是最大程度降低血管剩留风险的动向。