Confidence Intervals for Current Status Data

Abstract.  The likelihood ratio statistic for testing pointwise hypotheses about the survival time distribution in the current status model can be inverted to yield confidence intervals (CIs). One advantage of this procedure is that CIs can be formed without estimating the unknown parameters that figure in the asymptotic distribution of the maximum likelihood estimator (MLE) of the distribution function. We discuss the likelihood ratio-based CIs for the distribution function and the quantile function and compare these intervals to several different intervals based on the MLE. The quantiles of the limiting distribution of the MLE are estimated using various methods including parametric fitting, kernel smoothing and subsampling techniques. Comparisons are carried out both for simulated data and on a data set involving time to immunization against rubella. The comparisons indicate that the likelihood ratio-based intervals are preferable from several perspectives.     

基于Poisson分布需求的两级零售系统最优订货策略

考虑由一个分销中心和N个零售商组成的两级分销库存系统．假设两级库存补充均采取周期订货策略，在每个零售商处的客户需求是随机的，且服从Poisson分布．当给定的某一货物缺货时，顾客愿意等待特别订货的概率是一确定的常数，在满足给定的客户服务水平的条件下，寻求该供应链总费用的最小化．对库存费用的计算进行了精确的推导，并且得到了最优的订货策略．最后给出了一个算例，根据所得到的公式由电子表格获得了两级最优库存水平．     

On the preservation of copula structure under truncation

The author characterizes the copula associated with the bivariate survival model of Clayton (1978) as the only absolutely continuous copula that is preserved under bivariate truncation.     

论动物福利法的基本理念

“承认和维护动物福利,认可和维护动物的自然权利,尊重生命、善待动物、不虐待动物,保护动物福利也是保护人的利益,人与动物和谐相处,将科学精神与人文精神相结合”,这些是动物福利法的基本理念。动物福利法确认的是“动物的权利”,而不是“动物的人权”,更不是法律确认了动物是人。尊重生命是善待动物、不虐待动物的思想基础,不虐待动物是尊重生命的起码要求。科学精神是动物福利法的基础,人文精神是动物福利法的灵魂。只有形成并贯彻科学精神与人文精神相结合的理念,才能在一个汇集多种文明、多种主义、多种观念的多元化的当代社会,启动和推进动物福利立法。     

环渤海经济圈城市群能级梯度分布结构与区域经济发展战略研究

根据增长极理论、梯度转移理论和城市功能理论,构建了城市能级综合评价指标体系,并运用主成分分析法和SPSS软件对环渤海地区内的各城市进行了城市能级的综合评价,在此基础上又采用系统聚类分析法得到了环渤海经济圈城市群的层级分布结构,最后根据研究结果和相关理论提出了环渤海地区区域经济非均衡发展的建议和策略.     

Married women's resource position and household food expenditures in Cebu,Philippines

This study analyzes how married women use their access to and control over economic resources to increase household spending on food. Using data from Cebu, Philippines, where child malnutrition is high, this study finds that the more income women earn and control, the more households spend on food. Women's control over their income is particularly important for increasing food expenditures in the poorest households. In richer households, women who earn little of their own income also use spouse income transfers to increase food expenditures. The findings from this study suggest that in a developing country setting, improving women's economic status so that they earn and control more household resources can increase household spending on goods that benefit children.     

科技期刊的信息工作

阐述了信息工作在科技期刊办刊实践中的地位,归纳出信息工作的内容,即作者信息、读者市场信息、审稿人信息、报道领域的动态信息,以及学术出版业内信息等,并指出科技期刊应通过日常工作、学术会议、互联网络等渠道发布和收集信息。     

How can David orchestrate resources to enhance firm performance? A dynamic approach to coping with resource constraints

Given that the possession of abundant resources does not always guarantee superior firm performance, this study proposes a dynamic approach to enhancing firm value. Building on the resource orchestration thesis, we investigate how firms facing resource constraints enhance their capabilities over time by orchestrating resources and how this resource orchestration can play a role in improving firm performance. Using the dynamic perspective, this study identifies four resource orchestration modes, which are specified based on how a given firm dynamically allocates its resources to technology (enacted by R&D activities) and marketing (enacted by advertising activities). Accordingly, we claim that firms with resource constraints can enhance their performance by escalating or altering their resources over time. To test our hypotheses, we used a sample of 4078 small and medium-sized enterprises in manufacturing industries between 1984 and 2018. We found that focus escalation for technology positively affects firm performance, captured by Tobin's q, and that focus alternation toward either technology or market is positively related to firm performance. Finally, we discuss the theoretical and practical implications of our findings.     

职场孤独感对员工帮助行为的影响 ——基于资源保存理论视角

基于资源保存理论视角,构建了一个有调节的中介模型,实证研究了职场孤独感对员工帮助行为的影响。结果显示：职场孤独感对员工帮助行为具有负向影响,关系认同在职场孤独感与员工帮助行为之间起中介作用,自我控制资源损耗负向调节了关系认同与员工帮助行为之间的关系,自我控制资源损耗调节了关系认同在职场孤独感和员工帮助行为之间发挥的中介作用。基于此,企业应重视员工的职场孤独感并加强管理,采取相应激励措施鼓励员工提高关系认同感,补充自我控制资源,从而降低职场孤独感对企业组织的不利影响。     

汉语“噙含”“叼衔”义词的历时演变与共时分布

根据“嘴巴含”的方式,可以将“衔”分为“衔1”“衔2”,分别表示“全含”“半含”。前者与“含”“噙”构成“噙含”概念场,后者与“叼”构成“叼衔”概念场。表“噙含”义的词较多地分布在医籍文献中。“衔1”主要分布在诗词中。“噙”的产生对“含”造成一定冲击,但“含”在书面语中仍比较活跃。“含”“衔”“噙”均有从“东西放在嘴里,不咽下也不吐出→藏在里面;容纳→带有”的词义演变。“含”“衔”又均有从“藏在里面;容纳→隐藏”、从口部动作范畴到心理范畴的演变。表“叼衔”义,明代以前只有“衔2”。“叼”在明代始见,字形又作“雕”“刁”等。将历史文献与现代汉语方言分布相结合,推测“噙”发源于北方地区。“叼”很可能是“长江型”词,兴起于江淮流域而后往北向西扩散。