Monitoring the coefficient of variation using a variable sample size and sampling interval control chart

This article proposes a CV chart by using the variable sample size and sampling interval (VSSI) feature to improve the performance of the basic CV chart, for detecting small and moderate shifts in the CV. The proposed VSSI CV chart is designed by allowing the sample size and the sampling interval to vary. The VSSI CV chart's statistical performance is measured by using the average time to signal (ATS) and expected average time to signal (EATS) criteria and is compared with that of existing CV charts. The Markov chain approach is employed in the design of the chart.     

The heterogeneous impact of pension income on elderly living arrangements: evidence from China’s new rural pension scheme

This paper investigates the impact of pension income on living arrangements of the elderly. Taking advantage of a unique opportunity due to the recent establishment and expansion of the New Rural Pension Scheme in China, we explicitly address the endogeneity of pension status and pension income through a fixed-effect model with instrumental variable approach by exploiting exogenous time variation in the program implementation at county level. We find an overall positive effect of pension income on independent living as well as considerable heterogeneity. The positive income effects of the NRPS are concentrated among the elderly with adult children living nearby, of higher socio-economic status, and with better health at baseline; for other groups, the effects are insignificant. We also find that more generous programs exhibit larger effects. Our results highlight that living arrangement is multidimensional in rural China.     

孩次、生育时间与生育水平——基于中日韩妇女平均生育年龄变动与差异的机制研究

文章描述1990 ～2015年间中日韩三国妇女平均生育年龄的变化特征,揭示孩次结构和分孩次生育时间对平均生育年龄指标的影响,分析三国部及国家间妇女平均生育年龄时期变化与国别差异的影响机制.研究发现,观察期间中国妇女的平均生育年龄先下降后上升;平均生育年龄的提高是孩次减少与生育推迟共同作用的结果,后者的影响极为显著,但21世纪近5年的在机制表现值得关注.与日韩相比,中国妇女总体及分孩次的平均生育年龄都相对偏低;三国妇女的平均生育年龄上升态势后的在机制存在差异.文章还就平均生育年龄指标在衡量生育时间的准确性问题,以及全面两孩政策背景下生育时间在提升生育水平方面的政策意义进行讨论.     

教育扩张对大学毕业生收入的影响——基于断点回归设计分析

本文使用2012年"中国劳动力动态调查"数据②,基于断点回归方法评估高等教育扩招政策对收入的影响.本文的实证研究主要发现扩招政策对不同收入群体的影响不同,对低收入群体并无显著影响,但显著提高了高收入群体的收入,说明扩招促使高收入群体的高等教育收益高于低收入群体,这表明在一定程度上高等教育扩招政策并不利于社会公平,可能会造成居民收入差距进一步扩大.     

“一带一路”战略下西南跨境次区域农业一体化合作

近年来中国与西南周边毗邻的越南、缅甸和老挝等东盟三国跨境次区域经济合作紧密,在农产品贸易、农业技术合作、农业投资合作和农业产业合作等领域取得了较大成就,为跨境次区域农业一体化合作奠定坚实基础,同时跨境次区域凭借独特的地缘优势、经济互补性优势和“一带一路”建设历史机遇等有利条件为农业一体化合作提供重要动力,但同时也面临着互联互通基础设置不完善、农业市场体系不健全和农业政策不协调统一等障碍.因此,要推进西南跨境次区域农业一体化合作,需要从营造跨境次农业一体化合作环境、跨境次区域农业市场一体化合作、跨境次区域农业产业一体化合作和跨境次区域农业政策一体化等方面实现.     

试论近代中华民族共同体理论建构的内在紧张

中华民族共同体理论建构始于近代,主要涉及两方面的内容,一是中华民族的外在边界,一是其内部结构安排.近代中国民族主义是中华民族共同体理论建构的基础和开端,单元民族构成要素成为民族精英在中华民族共同体理论建构中援引的基本素材.同时,近代中国民族主义也造成了中华民族共同体理论建构的内在紧张:西方古典民族主义理论与中国多民族国家实际的错位、单元民族意识发展与中华民族共同体认同的冲突、进化论哲学与共同体建构援引资源历史性的矛盾.民族精英结合实际努力消解这一紧张关系,致力于实现“中华民族是一个”, “中华民族”最终成为凝聚民心、共赴国难的时代旗帜.     

Total completion time minimization in online hierarchical scheduling of unit-size jobs

This paper investigates an online hierarchical scheduling problem on m parallel identical machines. Our goal is to minimize the total completion time of all jobs. Each job has a unit processing time and a hierarchy. The job with a lower hierarchy can only be processed on the first machine and the job with a higher hierarchy can be processed on any one of m machines. We first show that the lower bound of this problem is at least \(1+\min \{\frac{1}{m}, \max \{\frac{2}{\lceil x\rceil +\frac{x}{\lceil x\rceil }+3}, \frac{2}{\lfloor x\rfloor +\frac{x}{\lfloor x\rfloor }+3}\}\), where \(x=\sqrt{2m+4}\). We then present a greedy algorithm with tight competitive ratio of \(1+\frac{2(m-1)}{m(\sqrt{4m-3}+1)}\). The competitive ratio is obtained in a way of analyzing the structure of the instance in the worst case, which is different from the most common method of competitive analysis. In particular, when \(m=2\), we propose an optimal online algorithm with competitive ratio of \(16\) \(/\) \(13\), which complements the previous result which provided an asymptotically optimal algorithm with competitive ratio of 1.1573 for the case where the number of jobs n is infinite, i.e., \(n\rightarrow \infty \).