关于p-超可解群的若干结果

给出了p-超可解群的若干刻划，通过严格p-闭群、拟正规子群等概念得到了p-超可解群相应的特征性质．     

BCI-代数的Ω-模糊p-理想(英文)

引入了BCI-代数的Ω-模糊p-理想的概念,研究了它们的相关性质.给出了BCI-代数的模糊p-理想与Ω-模糊p-理想的相互构造,研究了Ω-模糊p-理想的同态象与同态原象的性质;通过Ω-模糊p-理想的水平p-理想,讨论了BCI-代数的Ω-模糊p-理想的刻画;研究了BCI-代数的Ω-模糊p-理想与BCI-代数的积代数的Ω-模糊p-理想的关系.     

亚循环p-群的表示

亚循环p-群是可解群中非常重要的一类群,讨论亚循环群及亚循环分解的定义,和它的相关性质,如正则性,并最终给出了亚循环p-群的标准表示方法.     

｛（p,p-1）,（p,p-2）｝图对及树与（p,p-2）图的包装

给出了同阶图对{（p,p-1）,（p,p-2）}及同阶树与（p,p-2）图可包装的充要条件。     

关于Banach空间中三种框架概念的一些注记

讨论了Banach空间中的Banach框架，p-框架和p-阶框架之间的关系．引入了Banach框架的对偶框架，p阶框架的对偶框架和对偶框架对的概念，并且给出了p阶框架和Banach框架成为对偶框架对的充分必要条件。     

稀疏过程在保费随机收取风险模型中的应用

研究一类风险过程,其中保费收入为复合Poisson过程,而描述理赔发生的计数过程为保单到达过程的p-稀疏过程.运用鞅方法得出破产概率满足的Lundberg不等式和一般公式,给出当收取的保费和索赔额均为指数分布时破产概率的具体表达式,并通过数值计算研究了初始准备金的变化及保单到达和理赔发生之间的相互关系对保险公司经营的影响.     

限制李三系的型心

给出了限制李三系型心及拟型心的定义，研究了它们之间的结构关系.证明了限制李三系所有线性变换构成的集合End(T)为限制李三系、限制李三系型心和拟型心构成的集合为End(T)的p-子系；进而证明了限制李三系中心为零时，限制李三系的型心和拟型心可以分解为其p-理想的直和；在此基础上，给出了限制李三系中心为零时，若D∈C(T),则Im(D)和Ker(D)是T的p-理想.     

不含K3的（p,p-1）图和（p,p-2）图的包装

给出了不含K3的（p,p-1）图与同阶的（p,p-2）图可包装的充要条件。     

关于低阶BCI-代数计数问题的研究进展

概括介绍了低阶BCI-代数计数问题研究过程中的主要阶段性成果。本期学报所刊出的一组章完整解决了当阶数小于5时非p-半单、非BCK的BCI-代数类的数量问题，给出了在同构意义下不同的运算与汉斯图；给出了非平凡p-半单闭理想存在的实例，解决了BCI-代数研究中悬挂近十年的一个问题。     

有机化学中的p-电子云分析法

系统阐述了p-电子云分析法的孤单电子分析法、孤对电子分析法及空穴分析法(正电子分析法)三种方式,揭示了p-电子云分析法是开启物质反应及其转化规律的钥匙,是正确掌握有机化学理论体系的有效方法,论述了运用p-电子云分析法来理解与掌握有机化学理论体系。     

The effects of interrupted enrollment on graduation from college: Racial, income, and ability differences

We present a multiple spells-competing risks model of stopout, dropout, reenrollment, and graduation behavior. We find that students who experience an initial stopout are more likely to experience subsequent stopouts (occurrence dependence) and are less likely to graduate. We also find evidence of the impact of the length of an initial spell on the probability of subsequent events (lagged duration dependence). We simulate the impacts of race, family income, and high school performance on student behavior and show that there are often very large differences between unadjusted rates of student outcomes and adjusted rates. Differences in student performance often ascribed to race are shown to be the result of income, age at entry, and high school performance.     

ERP系统理论模型的设计与实现

基于提高企业ERP系统实施成功率,提出了如何找出适当的切入点、适当的模块及其相应步骤,获得企业资源计划(ERP.Enterprise Resource Planning)系统的理论模型;在此基础上,给出了一个企业资源计划(ERP)系统的简单实例。     

基于概率参数的Apriori改进算法

关联规则可在庞大的数据集中找出不同事务之间隐藏的关系,其中Apriori算法是关联规则分析中较为有效的办法。然而,Apriori算法产生候选项集的效率较低且扫描数据过于频繁,造成算法计算需要耗费较长时间。另外,初始定义的最小支持度与最小置信度也不足以过滤无用的关联规则。针对以上问题,利用概率理论与有效的参数设置,在原有Apriori算法基础上,提出一种基于概率事务压缩的关联规则改进算法。数值算例结果表明,新算法可在第二次迭代之后,大幅减少低效候选项集,从而提升经典Apriori算法效率。     

When does gender occupational segregation start? An experimental evaluation of the effects of gender and parental occupation in the apprenticeship labor market

The apprenticeship market is the earliest possible entry point into the workforce in developed economies. Since early labor market shocks are likely magnified throughout professional life, avoiding mismatches between talent and occupations – for example due to gender- or status-based discrimination – appears crucial. This experimental study investigates the effects of applicant gender and its interaction with parental occupation on the probability of receiving an invitation to an interview in the Swiss apprenticeship labor market. We find no robust evidence of differential treatment by employers in most cases. Policies aimed at fostering gender equality across occupations should therefore focus on removing gender related educational or cultural barriers influencing occupational choices at young ages.     

Knocking on the door to the teaching profession? Modeling the entry of prospective teachers into the workforce

We use a unique longitudinal sample of student teachers (“interns”) from six Washington state teacher training institutions to investigate patterns of entry into the teaching workforce. We estimate split population models that simultaneously estimate the impact of individual characteristics and student teaching experiences on the timing and probability of initial hiring as a public school teacher. Not surprisingly, we find that interns endorsed to teach in “difficult-to-staff” areas are more likely to find employment as public school teachers than interns endorsed in other areas. Younger interns, white interns, and interns who completed their student teaching in suburban schools are also more likely to find a teaching job, all else equal. Prospective teachers who do their internships at schools that have more teacher turnover are more likely to find employment, often at those schools. On the other hand, few of the characteristics of an intern's cooperating teacher are predictive of workforce entry. Finally, interns with higher credential exam scores are more likely to be hired by the school where they did their student teaching.     

夫兰克—赫兹实验的理论探讨

理清夫兰克—赫兹实验与玻尔理论的历史渊源,一些著名的原子物理学的教材中存在的对夫兰克—赫兹实验与玻尔理论的关系存在理解误区,大部分教材很容易让人误认为是在玻尔理论提出之后才有夫兰克—赫兹实验,实则不然.从理论上分析炉温的升高,电子与汞原子发生碰撞的概率增大,导致板极电流相应地减小.发射电压增大,由于单位时间发射的电子数增加,碰撞概率不变,所以板极电流相应增大.随着栅极电压的增加,由于电子初速度的增加,在通过KG空间时,与汞原子的碰撞概率减少,因此板极电流峰值增大.     

From high school to the high chair: Education and fertility timing

We exploit an expansion of post-compulsory schooling that occurred from the late 1980s to the early 1990s to investigate the effect of education on the timing of fertility in England and Wales. We do not find a significant effect on the probability of having a child as a teenager but instead find that the variation in education led to delays in childbearing. Our estimates suggest that an increase in education by one year led to a 5.3% increase in probability of first birth aged 24 or above, 9.4% increase in probability of first birth aged 27 or above, and 13.3% increase in probability of first birth aged 30 or above. The mechanisms driving these findings are not due to an incapacitation effect – by keeping young people in school or university they have less time or opportunity to have a child – but due to a combination of human capital and signalling effects.     

博士生的延期毕业率到底有多高 ——基于2017年全国离校调查数据的实证研究

基于2017年全国博士生离校调查数据进行的实证研究发现:博士生的平均延期率为39.68%,在延期群体中,48.15%的平均延期时间为一年,且延期率和延期时间在不同个体、不同学科及不同院校之间存在不同程度的差异性。进一步的回归分析发现:首先,自然科学中,男性延期概率显著低于女性;入学年龄越大,延期概率越高,延期时间也越长;博士生培养的贯通程度越高,则延期概率越低。其次,与人文学科相比,农学的延期概率显著更高而医学延期率显著更低;入选"一流学科"的博士生延期概率显著更低。第三,在自然科学中,院校层次越高,则博士生延期概率越高,但不同区域间延期率的差异并不显著。根据不同学科"内在规定性"和学科知识生产属性制定合理的培养周期是重要的改革趋势。     

文氏图在条件概率教学中的应用

条件概率是概率论的重要概念之一,也是概率统计教学中的一个难点,其关键是找到事件样本空间的一个划分,该文提出采用文氏图进行分析的方法,使样本空间的划分更直观、更易于分析,从而使复杂的条件概率概念的教与学得到有效解决.     

Does intensive coaching reduce school dropout? Evidence from a randomized experiment

School dropout is an important social and economic problem. This paper investigates the effect of an intensive coaching program aimed at reducing school dropout rates among students aged 16–20. Students received support and guidance with their study activities, personal problems and internships in firms. The coaching program lasted one or two years. Students were randomly assigned to the coaching program. We find that one year of coaching reduced school dropout rates by more than 40% from 17 to 10 percentage points. The second year of coaching further reduced school dropout by 1 percentage point. The program is most effective for students with a high ex-ante probability of dropping out, such as students no longer obliged to be in formal education, male students, and students not living with both parents. Cost-benefit analysis suggests that one year of coaching is likely to yield a net social gain.