Distributions in Statistics: Continuous Univariate Distributions-1 and 2

The density of a symmetric statistic T = g(X ₁, X ₂, …, X_n ), for a random sample from a mixed population with density f(x) = pf ₁(x) + pf ₂), is a binomial mixture of the densities of the statist.ics T_k = g(X_k1 , X_k2 , X_kn ), k = 0, 1, … n. where X_ki 's are independent with density f ₁(x) if i ≤ k and density f ₂(x) if i > k. It is shown how to find the distributions of some important symmetric statistics like sample mean, sample variance, and order statistics by using T_k 's. The results are applied to normal and exponential mixtures.     

基于视频的夜间车流量统计

根据夜间光照不充足的情况提出了一种有效的车流量统计算法。首先应用阈值化,分离出前景和背景,通过形态学腐蚀去除一些孤立的点以及特小区域,寻找联通区域丢弃小于设定范围的较小区域,利用形态学膨胀连接被分离的车头灯投射的光束;其次计算并判断连通区域的面积和范围,准确地提取出车灯对并且将其配对;最后通过比较前后两帧车头灯对的位置和面积对其进行跟踪,统计其车流量。实验表明,该算法复杂度较低,在良好环境下检测率可以达到97%以上。     

对《中国图象图形学报》论文和作者的统计分析

《中国图象图形学报》自１９９６年创刊以来已对中国图象图形科学技术的研究、应用和发展起到了重要的促进作用。该文根据文献计量学的原理和方法,对《中国图象图形学报》创刊４年以来所发表的论文和论文作者的情况进行了系统的调查和分析,这项工作揭示了中国图象图形科学研究者的现状,反映了《中国图象图形学报》创刊以来的发展情况,它既肯定了该刊作为图象图形学科核心期刊的合理性,又提供了发展该学科和办好该刊物的参考数据     

远程虚拟实验的构建

给出远程虚拟实验的技术原理与实现方法，按照基于虚拟原型的虚拟实验的一般原理，提出概率统计原理的虚拟实验方法以实现方案，基于Java语言，设计了一个远程虚拟实验系统并给出了几个实验实例。     

基于分箱统计的FCM算法及其在网络入侵检测中的应用

使用KDDCup99网络入侵检测数据,对传统的FCM(Fuzzy C-Means)算法进行实验,发现该聚类算法在进行聚类划分和孤立点判断时,存在划分粗略性现象.针对该问题,本文提出使用分箱统计的FCM方法来划分和描述数据集的分布.与原有算法相比,不需要频繁更新聚类中心,同时耗时问题也得到较好的改善.文章最后将特征匹配与基于分箱的FCM算法相结合,协同分析网络连接数据记录.实验结果证明,这种协同检测方法的检测率有明显提高,实时性好,能较好地发现新的攻击类型,便于检测知识库的更新.     

Digital capacity and employment outcomes: Microdata evidence from pre- and post-COVID-19 Europe

This paper examines the relationship between employment outcomes and broadband Internet access, education and digital skills using the pre- and post-COVID-19 survey waves of the Eurostat Community Statistics on Information Society from 2017, 2019, and 2021 in 27 European countries. Joint estimates of individuals’ employment status and skills employ external controls based on Eurostat and COVID-19 European Regional Tracker NUTS1-level regional statistics and Oxford COVID-19 Government Response Tracker information on governments’ containment and economic support measures. Broadband access, digital skills and educational attainment combine to raise employment outcomes, but COVID-19 has changed these relationships in distinct ways. It has increased employment benefits from formal education and roughly tripled the labor market advantages from having household members with tertiary education. The pandemic has increased the employment value of having at least some digital skills, while the relative benefits of more advanced digital skills shrank.