电话线传输自动报警系统的设计研究     

丁喜冬  邓妃易  刘泽民  江任荣 《中山大学学报论丛》1994,(4)

本文介绍一种通过公共电话网传递信息、用电脑进行控制的新型报警系统．文章对它的通讯性能进行了定性分析，并着重讨论了平均通讯时间和误报率等指标，设计出适合该系统的优化通讯．实验表明，这种设计方案是成功的．  相似文献   

基于平均逆映射的二阶通量分裂差分格式     

刘珺  郑华盛 《赣南师范学院学报》2012,33(3):8-11

基于通量分裂方法及逆风特性,通过引入平均逆映射概念,选取数值通量导数,结合二阶Runge-KuttaTVD时间离散方法,构造了求解双曲型守恒律方程的一个二阶无振荡中心差分格式.最后,给出几个标准数值算例,验证了格式具有形式简单,计算量小及高分辨率等优点.  相似文献   

清初李蕃治理黄县措施及成效探析     

赵光明焕力 《内江师范学院学报》2013,(11):79-84

在出任山东黄县知县期间,李蕃大力整顿县政.一方面,他围绕均赋减役、谋野便民、赈济灾荒、治土劝桑等方面推行了一系列整顿措施,改变了黄县经济凋敝、百姓流亡的局面;另一方面,他积极平息讼狱、整顿治安,并努力振兴教育、更易风尚,这些努力推动了该地在吏治、刑狱、教育和风俗等方面获得了较大的改善.  相似文献   

Globalised vs averaged: Bias and ranking performance on the author level     

Marcel Dunaiski  Jaco Geldenhuys  Willem Visser 《Journal of Informetrics》2019,13(1):299-313

We analyse the difference between the averaged (average of ratios) and globalised (ratio of averages) author-level aggregation approaches based on various paper-level metrics. We evaluate the aggregation variants in terms of (1) their field bias on the author-level and (2) their ranking performance based on test data that comprises researchers that have received fellowship status or won prestigious awards for their long-lasting and high-impact research contributions to their fields. We consider various direct and indirect paper-level metrics with different normalisation approaches (mean-based, percentile-based, co-citation-based) and focus on the bias and performance differences between the two aggregation variants of each metric. We execute all experiments on two publication databases which use different field categorisation schemes. The first uses author-chosen concept categories and covers the computer science literature. The second covers all disciplines and categorises papers by keywords based on their contents. In terms of bias, we find relatively little difference between the averaged and globalised variants. For mean-normalised citation counts we find no significant difference between the two approaches. However, the percentile-based metric shows less bias with the globalised approach, except for citation windows smaller than four years. On the multi-disciplinary database, PageRank has the overall least bias but shows no significant difference between the two aggregation variants. The averaged variants of most metrics have less bias for small citation windows. For larger citation windows the differences are smaller and are mostly insignificant.In terms of ranking the well-established researchers who have received accolades for their high-impact contributions, we find that the globalised variant of the percentile-based metric performs better. Again we find no significant differences between the globalised and averaged variants based on citation counts and PageRank scores.  相似文献   

基于混合过程的衍生证券定价策略分析   总被引：5，自引：0，他引：5  

田军  郭耀煌 《预测》1999,18(6):59-61

本文通过对标的资产的价格行为过程进行分析,引入一种基于混合过程的新的期权模式,推导出一种新的期权定价模型,并给出了期权定价模型的解析公式及均匀中心差分求解法  相似文献