Persistence factors revealed: students’ reflections on completing a fully online program

Despite their rapid growth, online programs routinely face student attrition. How to retain students and help them successfully complete is usually a top priority for online programs. This study investigated persistence factors that contributed to students’ successful completion from one of the largest and most successful online programs in the United States of America. Results show that both personal and program attributes contributed to students’ successful completion of a fully online program. Main individual attributes include interest in or career goals related to technology, time and effort invested, and perceived utility of learning. Main program attributes include relevancy of courses to individual or professional needs, satisfaction with courses and program, and ties between coursework and job promotion. Results of this study have implications in terms of prioritizing different attributes and strategizing resources to improve completion and graduation rates for fully online programs.     

基于视觉暂留的验证码设计

验证码能够有效抵御网络中机器程序的自动登录行为,防止机器程序群发垃圾邮件和自动投票等非法行为。但是随着图像识别技术和人工智能的发展,传统的验证码面临着被机器程序自动破解的危险。文章在分析不同验证码的优缺点后,提出一种基于人眼视觉暂留现象的动态验证码,利用有效字符和干扰字符混合组成多帧动态图像,普通用户可以轻易识别,而机器程序难以区分,理论分析和模拟实验证明该验证码简单有效。     

三环顶球的制作与演示

本文介绍一种演示视觉暂留现象和颜色合成的实验装置——三环顶球,简述该装置的制作过程和操作方法。     

Educational Attainment as Process: Using Hierarchical Discrete-Time Event History Analysis to Model Rate of Progress

Variables that address student enrollment patterns (e.g., persistence, enrollment inconsistency, completed credit hours, course credit load, course completion rate, procrastination) constitute a longstanding fixture of analytical strategies in educational research, particularly research that focuses on explaining variation in academic outcomes. However, nearly all measures of enrollment patterns are handicapped by untested assumptions about a more fundamental measure, namely students’ rate of progress. In this paper, I first explain how a variety of widely used measures of enrollment patterns are inextricably linked to students’ rate of progress. I then describe a method of modeling mathematically students’ rate of progress that employs hierarchical (multilevel) discrete-time event history analysis of repeated events. I conclude with an empirical example of the application of this method in which I test several hypotheses concerning students’ rate of progress through the remedial math sequence toward the outcome of college-level math competency. In addition to the utility of the method that is proposed here, the issues discussed in this paper have important practical implications for institutional research, particularly with respect to the use of the various measures of enrollment patterns to explain variation in students’ attainment.

影响社区居民体育锻炼坚持性的思考

社区居民体育锻炼坚持性的影响因素多种多样,究其根源主要来自于个体和环境两个方面,其中个体因素是制约社区居民体育锻炼坚持性的主要因素。本文运用文献资料法,走访调查法和典型个案分析等多种方法针对社区居民体育锻炼坚持性影响因素进行研究,提出相对应的干预措施,为社区居民坚持体育锻炼和形成健康的生活方式提供有益的参考。     

基于Hibernate的数据持久化应用研究

Hibernate是一个对象持久化工具,它通过其强大的O/R映射功能将Java对象同存放于关系数据库中的数据进行映射,避免了开发人员使用大量的SQL语句通过JDBC的方式对数据库进行操作,可以有效地提高开发的效率。将其应用于企业在线资产管理系统,可充分利用其优点。     

Factors that influence pre-service teachers' persistence

This study investigated the role of various factors in pre-service teachers' persistence. Using a sample of U.S. pre-service teachers (N = 1365) from 256 institutions, the study explored the joint effect of predictors that influence their persistence including student engagement, demographic characteristics, prior achievement, college grades, and institutional characteristics. Results from multilevel logistic models indicated that campus environment engagement was a weak but positive predictor of persistence, those with higher grades were more likely to persist, and male and minority pre-service teachers were less likely to persist. Implications include implementing evidence-based programs to improve campus environment and support at-risk candidates.     

Laboratory simulated dissipation of metsulfuron methyl and chlorimuron ethyl in soils and their residual fate in rice, wheat and soybean at harvest

Two sulfonylurea herbicides, metsulfuron methyl （Ally 20 WP） and chlorimuron ethyl （Classic 25 WP） were evaluated for their dissipation bchaviour in alluvial, coastal saline and laterite soils under laboratory incubated condition at 60% water holding capacity of soils and 30 ℃ temperature was maintained. In field study herbicides were applied twice for the control of grasses, annual and perennials broad leaves weeds and sedges in rice, wheat and soybean to find out the residual fate of both the herbicides on different matrices of respective crops after harvest. Extraction and clean up methodologies for the herbicides were standardized and subsequently analyzed by HPLC. The study revealed that the half-lives of metsulfuron methyl and chlorimuron ethyl ranged from 10.75 to 13.94 d irrespective of soils and doses applied. Field trials with rice, wheat and soybean also revealed that these two herbicides could safely be recommended for application as no residues were detected in the harvest samples.     

北方农牧交错区降水过程的持续性特征与干旱发生趋势

过去50多年来,环境脆弱的北方农牧交错带中部区域增温明显且干旱频发,对生态系统和农牧民的生计造成极为严重的影响。认识该区域降水过程的持续性特征对准确预测未来可能面临的灾害事件及政策调整有重要意义。本文采用时序距平分析法与基于分形理论的重标极差分析法相结合的方式,详细分析了北方农牧交错带中部地区6个站点1956年-2009期间降水变化过程及其持续性特征。结果表明,研究区过去54年间的年降水量总体呈下降趋势,夏季降水量年际变化曲线与年降水量变化曲线基本一致,但春季降水量略有上升;在1年与5年时间尺度上,年降水量和各季节降水量变化均呈剧烈波动态势。值得注意的是,在5年时间尺度上,Hurst指数在整个研究区域上的平均值比其在1年时间尺度上的平均值更接近于1．0,即随着时间尺度的增大,降水过程的自相关性、持续性增强明显。在10年尺度上,研究区全年少水期的出现即距平值为负值的持续时间长约10年,而春季少水期出现的持续时间则可能长达20．30年。     

Financial aid and student persistence in online education in the United States

Distance education has historically had lower completion rates. Several models of persistence, for on-campus students, indicate that students’ financial status affects their decision to persist. This study involved providing distance education students’ financial aid in the form of institutional scholarships (N = 545) at Penn State University in the United States. The recipients were students who were not overachievers and not at-risk of failing, but somewhere in the middle. The purpose of the study was to test if receiving financial aid was related to students’ persistence. Using logistic regression and Chi-square analysis, this study found that scholarship-receiving students with higher financial need were two times more likely to persist in their studies than those with lower financial need. Results suggest that there is a positive relationship between providing even small financial aid to students with high-financial need and their persistence in their studies.