工业废水中TOC与COD的相关分析

采用回归分析,对大庆石化公司炼油废水COD（有机碳）与TOC（化学需氧量,也叫CODcr）的相关性进行研究,以便快速预报废水COD值。结果表明,废水TOC与COD数值之间线性关系显著。在生产稳定的情况下,只需测定废水TOC,就可通过回归方程预测COD。     

The impact of the Gates Millennium Scholars Program on college and post-college related choices of high ability,low-income minority students

In this paper we analyze the impact of the Gates Millennium Scholarship Program on several outcome variables using a regression discontinuity design. We find that GMS recipients have lower college loan debt and parental contributions toward college expenses and work fewer hours during college than non-recipients. We also find that GMS recipients have higher grade point averages in their junior year of college and are more likely to aspire to a Ph.D. degree than non-recipients.     

Do organizational variables influence satisfaction with nursing student practices?

Clinical practices are a vital component in the education of registered nursing students. This study analyzed the influence of organizational variables on satisfaction with clinical practices. A cross-sectional study design involved 572 registered nursing students. Two statistical methodologies, hierarchical regression models and qualitative comparative analysis of diffuse sets, were used for data analysis. In the hierarchical regression models the number of students supervised predicted satisfaction with clinical educator (β = -.22; p ≤ .001), environment (β = -.13; p ≤ .05) and overall satisfaction (β = -.15; p ≤ .05). However, in the qualitative comparative analysis, the type of center, as well as the number of services assigned to the clinical educator and the number of students per clinical educator period were conditions that influence satisfaction with clinical practices. The type of center and the clinical educator are key factors related to registered nursing students’ satisfaction with clinical practices.     

COVID-19 impact on jobs at private schools and colleges in Northern Ethiopia

The disruptive effects of COVID-19 have impacted all sectors of our society including education. This study identified the factors influencing the private schools’ and colleges’ decision to reduce their teaching staff during the COVID-19 lockdown using survey data analyzed using Heckman two-step regression model. The results showed that age, accommodation level, hourly payment rate, tax grade level, money borrowed from government or banks, loan repayment suspension, tax payment deferral, the number of administrative employees, the student-to-administrative employee ratio, and the educational institution’s category were the significant factors affecting teaching employee reduction during the lockdown. The results of this study can help the various education sector stakeholders to take coordinated measures to withstand COVID-19 type of shocks.     

城市居民低碳消费行为及影响因素研究——以福建省福州市为例

由城市居民消费产生的碳排放量问题日益突出,并对空气质量及生态环境构成一定的威胁。本文通过对福州市城区的实地问卷调查,运用描述统计、单因素方差模型和多元线性回归模型实证分析了城市居民的低碳消费行为问题。研究结果显示:当前城市居民实施低碳消费的行为倾向处于中等略偏上的水平,反映出调控城市居民低碳消费行为的重要性;人口统计学变量对于城市居民低碳消费行为的影响并无显著差异,反映出低碳消费并没有"专属区",具有明显的社会共性特征;而"价值观"、"关注度"、"行政性政策"、"操作能力"、"社会规范"5个变量对城市居民低碳消费行为产生了显著的正向影响作用,反映出心理因素、法规政策及外部因素等会对低碳消费行为产生影响作用。因此,建议开展全员式的低碳消费理念普及与教育活动,引导城市居民正确认知低碳消费行为对自身、经济发展及生态环境产生的价值,提高城市居民实施低碳消费行为的操作能力,并适时出台促进实施低碳消费行为的相关法规政策,从而努力减少由城市居民消费所产生的碳排放量以推动可持续发展。     

一种新的多元回归思路——因子与回归联合分析法

多元回归分析是一种重要的数据处理方法,变量的多重共线性诊断是回归分析的重要环节.针对传统的多元回归分析中变量间的多重共线性问题,提出一种新的求解多元回归问题的思路,该思路与传统方法相比具有明显的优势.     

我国城镇居民消费与收入关系分析——基于地理加权回归模型(GWR)的实证分析

空间数据一般具有空间非平稳性的特点,究其原因是地理空间上的区域缺乏均质性,存在高消费地区和低消费地区、中心(核心)和外围(边缘)等经济地理结构,从而导致我国城镇居民消费存在较大的空间差异性。对此,本文试图采用地理加权回归模型来分析我国城镇居民消费与收入的关系,从实证分析的结果提出几点建议和对策。     

基于多项式样条回归的基尼系数的算法

基尼系数的测算目前有分布函数法、几何计算法与曲线拟合法。本文推导出洛伦兹曲线的三次分段多项式样条函数拟合的简单表达式,再通过样条回归确定系数,从而可以比较精确地求出基尼系数,并在此基础上进行了实证分析,且计算结果比文献[6]的结果要精确。     

伊犁新垦区土壤全盐量和电导率定量关系探讨

土壤含盐量和电导率是调查评价土壤盐渍化程度的两种指标,进行两者关系的定量探讨是解决土壤盐渍化快速诊断问题的前提。本文以伊犁新垦区为例,采用传统的一次函数、二次函数和分段函数等对土壤含盐量和电导率关系进行回归拟合,同时应用土地利用类型、植被类型和土壤类型等环境因子作为辅助数据对两者进行分区线性拟合,并分析比较两种方法的优劣。结果表明,随着全盐量的增加,土壤全盐量和电导率呈现一定的非线性关系,以土壤全盐量为阈值的分段函数拟合效果优于一次函数和二次函数,其RMSE小于后两者;以土地利用类型作为辅助数据进行的分组拟合结果优于植被类型和土壤类型的效果,也略优于分段函数的拟合精度。该方法在宏观尺度上为快速、精确获取土壤盐分状况提供帮助。