The effects of an edgeline on speed and lateral position: a meta-analysis

This paper presents a meta-analysis of studies that have evaluated the effects of an edgeline on speed and lateral position of motorised road users. Together with many other study characteristics, 41 estimates of the effects of an edgeline on speed and 65 on lateral position were extracted from the studies. The results of the evaluation studies show a great variety in effects. Both negative and positive effects on speed and lateral position were found; amongst others, increases in speed up to 10.6 km/h, as well as decreases in speed up to 5.0 km/h, and shifts of the lateral position towards the centre of the road up to 30 cm, as well as shifts towards the edge of the road up to 35 cm. Further analyses resulted in the determination of study characteristics that influence the effects of an edgeline on speed and lateral position. It is concluded that the effects of an edgeline on speed are related to the presence of a centreline. Applying an edgeline to a road without a centreline increases the speed of road users, and replacing a centreline by an edgeline decreases the speed. Results with respect to adding an edgeline to a road with a centreline were unclear. Another conclusion is that shoulder width and road environment contribute to the effects of an edgeline on lateral position. In combination with wide shoulders or buildings and/or trees next to the road, edgelines lead to shifts of the lateral position towards the edge of the road, and in combination with narrow shoulders or open fields, edgelines lead to shifts towards the centre of the road.     

Allomonal secretions in cockroaches

We have analyzed the allomonal secretions in 10 species of cockroaches belonging to seven genera and made a detailed reanalysis of these secretions in three other species previously studied. Forty-three products were identified (quinones, phenols, acids, ketones, aldehydes, lactones, hydrocarbons, alcohols and various products). In many cases, the function of these secretions is unknown. We were able to test in the laboratory and also in natural conditions the different products identified, and we were able to test the reactions of several cockroaches when attacked by natural predators (beetles, lizards, toads, and bats). InEurycotis decipiens, the secretion of the sternal glands has a strong deterrent effect on the predators. InEublaberus distanti, the secretion of the glands associated with the second abdominal spiracle acts as an alarm pheromone. In several species ofPeriplaneta, the function of the sternal secretions is unknown. The components of these allomonal secretions are discussed.     

Mode of failure, interference tendencies, and achievement imagery.

The relative effects upon addition performance of failure to reach goals set by the subject himself and failure to reach goals set by the experimenter are studied, as well as the relative performance of groups differing in scores on the Interfering Tendency Questionnaire (IT) and the Achievement Imagery (AI) scale of the Iowa Picture Interpretation Test. The major findings were as follows: (1) There was no overall difference in the effects of the two failure procedures. High AI Ss showed greater improvement following failure to reach goals they had set for themselves while low AI Ss showed greater improvement following failure to reach experimenter set goals. (2) Under failure conditions, low IT Ss were superior, while under non failure conditions, high IT Ss were superior. (3) High AI Ss worked significantly faster than low AI Ss. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

正定Hermite矩阵特征值的相对扰动界

给出了正定Hermite矩阵特征值的一个新扰动界,同以往的结论相比我们的界形式上更简洁而且新的扰动界在合同变换下保持不变。     

低温制冷机的性能评价

作为对制冷系数COP概念的补充,建议采用yong效率（Exergy Efficien-cy）的概念来综合评价多级低温制冷机的性能,同时也为其性能优化过程提供理论指导。本文还以yong效率为基础,综合评价了4.2K和80K温区低温制冷机的发展水平,具有一定参考价值。     

智能化中压开关柜的监测和传感技术(一)

文章综述了用于中压开关柜监测、测量的两大类传感器:电流和电压测量保护用传感器,非电量数值传感器。新型的电流和电压传感器优越性明显,在解决了细节及接口问题后,将逐渐安装使用。非电量数值传感器技术是将开关柜“定期”维护转变为“按状态”维护的关键技术,有很好的应用前景。     

智能化中压开关柜的监测和传感技术(二)

文章综述了用于中压开关柜监测、测量的两大类传感器：电流和电压测量保护用传感器;非电量数值传感器。新型的电流和电压传感器优越性明显,在解决了细节及接口问题后,将逐渐安装使用。非电量数值传感器技术是将开关柜“定期”维护转变为“按状态”维护的关键技术,有很好的应用前景。     

仿人灵巧手关节的位置/力矩控制

为了使仿人灵巧手完成各种精细作业,提出了一种新的关节位置／力矩控制方法。在自由空间和约束空间中分别采用滑模位置控制和具有前馈的PD力矩控制,在过渡过程中使用系统观测器切换控制模式。这种方法可以使关节在自由空间和约束空间中分别实现良好的轨迹跟踪和力矩跟踪,在过渡过程中实现控制模式的可靠切换和系统的稳定过渡。实验证明了该方法的有效性。     

USB电气特性

USB的电气特性反映了端口驱动电路,传输电平,编码结构,位同步处理及供电方式,USB串行数据采用了NRZI编码,在USB数据线上传输,对数据进行差分编码有助于噪声抵消和确保数据的正确性,给出了驱动信号的波形和阈值,为了避免长“1”码影响同步信号的提取,USB采用了“0”翻转插入方式,USB端口对于相连的设备均可提供2种供电方式,即总线供电方式和自供电方式。     

GB18030汉字信息的二维条码拆分迭代编码算法

为了解决二维码在证件类应用中常常面临的冷僻字编码问题，以GB18030字符集为对象分析汉字编码特点，提出基于该标准的汉字与ASCII混合信息的PDF417编码方法。并针对当前广泛应用的16位编程工具，结合实例给出了一种拆分迭代编码算法来实现字节压缩模式，它能够在保证较高编码效率的基础上有效节省编码存储空间。