电动车骑行者碰撞风险感知研究

研究电动车骑行者碰撞风险感知的影响因素及其各种情形下碰撞风险感知的差异. 设计基于危险情形的问卷,通过网上收集问卷获取数据,采用因子分析和Logistic模型等统计方法,对电动车骑行者碰撞风险感知进行了研究. 结果表明:驾驶技能、出行频率、年龄、冒险倾向等因素对风险感知有显著影响;电动车分别与小汽车、电动车、自行车发生碰撞时,风险感知依次下降;同一情形下,骑行者自己失误比他人失误引发的碰撞风险感知更低.     

数字图像的质量评估

围绕数字图像的质量评估,进行了简要综述。分析了主观评估和客观评估各自的优缺点,回顾了传统的全参考图像质量评估方法;介绍了已广泛用于客观质量评估的人类视觉特性与感兴趣区域;列举并评述了2类代表性的全参考质量评估模型SSIM和FSIM;总结了无参考质量评估的一些特点和动向;最后对该领域未来的研究方向进行了展望。     

Exploring on-line societal risk perception for harmonious society measurement

The nearly 30-year economic growth miracle brings the consequent tremendous poor-rich gap leading strong drives for social transformation in current China. Chinese top leaders have realized to increase the peoples＇ income, improve quality of life and construct a ＂harmonious society＂ as key missions especially in recent 10 years. How to measure a harmonious society is one important topic as different measures may lead to different development policies. This paper outlines over 10 indices relevant to measure a harmonious society. Some are global indicators, while some are contributed by domestic researchers and arouse debates. Most of those indicators require conducting surveys on social attitudes under micro levels, which is always time consuming with problem of data quality. As Internet technology advances provide ways to record and disseminate fresh community ideas and thoughts conveniently, detecting topics or emotions from on-line public opinions is becoming a trend or one supplement way to overcome those data acquisition problems. This paper discusses one approach to on-line societal risk perception using hot search words and BBS posts. Such a trial aims to provide another way to societal risk perception different from those in traditional socio psychology studies. Challenges are also indicated.     

群集运动行为的模型构建与计算机仿真

以某群体为研究对象,构建了一个连续的三维空间．在空间中,依据3个行为规则,将个体的感知范围划分为排斥区域、一致区域和吸引区域3个行为区域,并分别得出了各行为区域对个体速度方向的影响公式．将3个行为区域对个体的影响抽象为3个作用力,个体总的速度方向由各作用力产生的速度方向分量共同决定,分别给出各作用力权重因子,最终计算出迭代至第t步时个体总的速度方向,进而推算出t＋1步时个体的位置向量和速度向量．最后,利用Matlab仿真模拟了群集运动行为在三维空间内的运动情况．仿真结果表明,所构建的模型能有效地模拟动物的群集运动行为．     

Relationship between perceptual and semantic levels of representation: An event-related potential study

An event-related potential study was conducted to make clear the relationships between perceptual and semantic levels of representation. Subjects judged the semantic relationship between a picture sample and a word match using the delayed match-to-sample paradigm. The experiment includes three types of matching trials, i.e., identical match trials, where the words had the same meanings as the pictures, categorical match trials where the words matched the pictures in category, and non-match trials where the words matched neither in identification nor in category with the pictures. The three conditions evoke significantly different N400-1ike and P300 ERP components. Specifically, for the N400-1ike negative responses, the averaged amplitude of the non-match condition is the largest and the most negative-going, that of the categorical match condition is less negative-going, and that of the identical match condition is the smallest among all three conditions. In addition, only the identical match condition evokes an early P300 component. As for the late P300 component, the averaged amplitude of the categorical match condition is more robust in the frontal brain areas. In contrast, ERPs of the non-match condition are stronger in the posterior brain areas. From 250 to 450 ms, the difference waves between the identical match and non-match conditions are located in the central areas, and the difference waves between categorical match and non-match conditions occur in the right frontal areas. Our results suggest that cross-form picture-word identical matching and categorical matching involve different underlying mechanisms. The existence of the early P300 component evokes by the identical match condition provides support for theories of template matching and facilitation model.     

三维空间中异构传感器网络的目标覆盖

在传感器随机分布的目标覆盖问题中,针对由感知属性不同的普通节点和超级节点构成的异构传感器网络,在三维空间中基于概率感知模型,结合免疫优势克隆算法来进行目标覆盖问题的优化．由免疫优势克隆算法提供的传感器节点最少等效个数的寻求方法,保证了随机分布于三维空间里的可感知的目标点能够全部被覆盖到．实验结果表明,与目前解决此问题最好的遗传算法相比,在达到与遗传算法相同覆盖质量的条件下,免疫优势克隆算法有效提高了实时性,明显降低了寻优时间．     

佛山城市行道树生长现状调查

实地调查了佛山市９６条干道或交通繁忙街道的２２２７６棵行道树,详细记录了各树种的生态习性,统计分析出该市城区的主要行道树组成情况及其生长现状,可供进一步分析研究环境因素对行道树的影响及园林绿化工作参考。     

事故分析透视企业安全文化建设的新思考

通过对2013年初吉林通化八宝煤矿事故的分析,企业安全文化建设的重要性在于:首先,员工对安全文化、安全风险要有真实感知;其次,要坚持具体情况具体分析,不同地区、不同企业,不能按照同一个安全标准原则建设;再次,企业内不同层级安全文化建设的重点,也应有不同。文化的本质是意会,重制度,讲规则,实事求是是最基本的安全文化。     

基于三维激光雷达的路沿检测算法

为了在多种道路环境下准确提取智能汽车前方道路路沿,提出一种基于三维激光雷达的路沿检测算法。该算法采用随机采样一致性算法(random sample consensus, RANSAC)快速分割出道路区域,滤除了大部分非地面数据,提高后续步骤的处理速度;提出一种基于无向图邻域关系的多特征、宽阈值、多层次路沿特征提取算法,通过构造多种路沿几何特征设置较宽阈值以提高路沿检测精度;采用双向扫描线搜索算法获取路沿候选点,根据路沿特征点密度和全局连续性的特点进行聚类分析并去除噪声,用二次曲线拟合道路路沿。结果表明,该算法能够在车辆、行人和障碍物遮挡的情况下有效识别结构化直、弯道路路沿,算法准确率均高于86%,且检测道路宽度误差小于0.19m,验证了算法的鲁棒性和准确性。     

基于粒子群优化的支持向量机用于直肠感知功能重建

针对临床上肛门失禁导致的直肠感知功能丧失,提出了一种基于粒子群优化(PSO)的支持向量机(SVM)重建患者直肠感知功能的方法.分析人体直肠压力生理特征,将典型直肠压力收缩波形中的巨大移行性收缩(HAPC)作为产生便意的主要依据,利用小波包分析对直肠压力信号进行特征提取,通过提取的特征向量对基于SVM的直肠感知预测模型进行训练,使用PSO算法对SVM的参数进行优化,并利用训练后的模型进行便意预测,同时对比分析了参数优化后的SVM和不同核函数的SVM便意预测的准确率.实验结果表明,所提出方法切实有效,能够帮助患者重建直肠感知功能.