The effect of toxicity on COVID-19 news network formation in political subcommunities on Reddit: An affiliation network approach

Political polarization remains perhaps the “greatest barrier” to effective COVID-19 pandemic mitigation measures in the United States. Social media has been implicated in fueling this polarization. In this paper, we uncover the network of COVID-19 related news sources shared to 30 politically biased and 2 neutral subcommunities on Reddit. We find, using exponential random graph modeling, that news sources associated with highly toxic – “rude, disrespectful” – content are more likely to be shared across political subreddits. We also find homophily according to toxicity levels in the network of online news sources. Our findings suggest that news sources associated with high toxicity are rewarded with prominent positions in the resultant network. The toxicity in COVID-19 discussions may fuel political polarization by denigrating ideological opponents and politicizing responses to the COVID-19 pandemic, all to the detriment of mitigation measures. Public health practitioners should monitor toxicity in public online discussions to familiarize themselves with emerging political arguments that threaten adherence to public health crises management. We also recommend, based on our findings, that social media platforms algorithmically promote neutral and scientific news sources to reduce toxic discussion in subcommunities and encourage compliance with public health recommendations in the fight against COVID-19.     

基于反向随机投影的神经网络改进算法

提出基于反向随机局部投影的神经网络效率改进算法，通过降低深度学习中的网络规模，重点解决了从“局部连接”到“全连接”和随机节点抽取时输入端节点信息丢失的问题，从而提升网络的效率。在算法中设置缩减参数，提升了算法的可伸展性，以适用于不同数据集的学习。通过数据集ISO-LET进行实验，结果表明，基于反向随机局部投影的神经网络效率改进算法的准确率、效率分别平均提升了3.48%和105.21%?在迭代20次的实验中进行了缩减参数调节实验，当参数设置为1.4时其准确率则优于传统全连接网络2.61%，效率提升了272.78%，具有明显的优势。     

一类宽平稳量子随机过程及实例分析

定义了"宽平稳量子随机过程"的概念,获得了其谱分解定理.辅以统计物理学中的实例为基础.     

算子迹算术-几何平均不等式

利用泛函分析方法将半正定矩阵迹不等式|tr(A1A2…Am)|1m≤1m(trA1 trA2 … trAm)推广到Hilbert空间,并得到相应的正迹类算子不等式.     

非连续单调算子的不动点定理

在Banach空间E中，利用正规锥的性质及压缩原理，通过上下解方法构造出一组迭代序列。所得序列均为Banach空间E中的柯西序列，再利用E的完备性，从而得到非连续单调算子的最大与最小不动点。改进推广了某些已有的结果．     

分数阶Feller算子下的反常扩散方程

建立了Feller算予以下的空间分数阶反常扩散方程,给出分数阶扩散方程Canchy问题的求解定理,借助定理、Fourier变换及伽利略变换不变性得到问题的精确解,并当α→2即θ→0时,问题的解与相应经典整数阶扩散（对流-扩散）方程的解一致．     

Sample, Random and Variation: The Vocabulary of Statistical Literacy

This paper considers the development of school students’ ability to define three terms that are fundamental to statistical literacy: sample, random, and variation. A total of 738 students in grades 3, 5, 7, and 9 were asked in a survey to define and give an example for the word “sample.” Of these, 379 students in grades 7 and 9 were also asked about the words “random” and “variation.” Responses were used to describe developmental levels overall and to document differences across grades on the understanding of these terms. Changes in performance were also monitored after lessons on chance and data, emphasizing variation for 335 students. After 2 years, 132 of these students and a further 209 students who were surveyed originally but did not take part in specialized lessons, were surveyed again. The difference after 2 years between the performance of students who experienced the specialized lessons and those who did not was considered, revealing no differences in performance longitudinally. For students in grades 7 and 9, the association of performance on the three terms was explored. Implications for mathematics and literacy educators are discussed.     

带右删失数据的非线性随机效应模型参数估计

本文讨论了带右删失数据的非线性随机效应模型的参数估计,给出Gauss-Newton迭代法和改进后的Gauss-Newton迭代法,根据参数估计和算法给出数值模拟,验证了参数估计和算法的可行性.     

随机截尾寿命试验两参数Pareto分布的Bayes统计分析

利用随机截尾寿命试验数据,给出了两参数Pareto分布参数．可靠度和换效率的Bayes点估计及其置信限．     

基于CRI算法的Hα系统蕴涵算子模糊系统

首先讨论了基于CRI算法的模糊系统及其响应性能,结果表明,蕴涵算子Rp模糊系统只具有阶跃输出能力,不具有函数逼近泛性;其次揭示了蕴涵算子Rp模糊系统的概率意义,给出了其概率分布,它充当模糊系统的“系统内核”作用．