Confidence intervals for coefficients of variation in two-parameter exponential distributions

This article examines confidence intervals for the single coefficient of variation and the difference of coefficients of variation in the two-parameter exponential distributions, using the method of variance of estimates recovery (MOVER), the generalized confidence interval (GCI), and the asymptotic confidence interval (ACI). In simulation, the results indicate that coverage probabilities of the GCI maintain the nominal level in general. The MOVER performs well in terms of coverage probability when data only consist of positive values, but it has wider expected length. The coverage probabilities of the ACI satisfy the target for large sample sizes. We also illustrate our confidence intervals using a real-world example in the area of medical science.     

Joint estimation of multiple high‐dimensional Gaussian copula graphical models

A joint estimation approach for multiple high‐dimensional Gaussian copula graphical models is proposed, which achieves estimation robustness by exploiting non‐parametric rank‐based correlation coefficient estimators. Although we focus on continuous data in this paper, the proposed method can be extended to deal with binary or mixed data. Based on a weighted minimisation problem, the estimators can be obtained by implementing second‐order cone programming. Theoretical properties of the procedure are investigated. We show that the proposed joint estimation procedure leads to a faster convergence rate than estimating the graphs individually. It is also shown that the proposed procedure achieves an exact graph structure recovery with probability tending to 1 under certain regularity conditions. Besides theoretical analysis, we conduct numerical simulations to compare the estimation performance and graph recovery performance of some state‐of‐the‐art methods including both joint estimation methods and estimation methods for individuals. The proposed method is then applied to a gene expression data set, which illustrates its practical usefulness.     

投资回收期指标若干问题的探讨

针对基本建设投资回收期指标的正确计算问题 ,从固定资产折旧基金和我国税金的性质、特点入手 ,阐述了折旧和税金应是投资回收资金的观点 ,并认为流动资金的投资也应列入应回收的总投资的范围     

突发事件后生产运作系统的能力应急管理模型研究

分析了因突发事件而能力受损生产运作系统在应急期间应急管理模式,围绕系统内部能力恢复和外部能力采购,综合考虑高额社会惩罚成本,以应急期间的运作总成本（也即总损失）最小为目标构建了多阶段的能力应急模型。通过随机动态规划算法对模型进行数值仿真后得到4个重要的管理学结论,对生产型运作系统应急预案的制定、能力协作伙伴的选择、能力恢复投资以及应急时间跨度的决策均具有重要的指导意义。     

Daily recovery from work: The role of activities,effort and pleasure

Abstract

Knowledge of the cycle of work and recovery is crucial for protecting employee health and well-being and preserving working capabilities. However, the daily process of effort and recovery is not well understood. This study investigated how the time spent on activities in the work and off-job domains, and the pleasure and effort experienced while engaging in these activities, affect the daily recovery process. We expected higher levels of effort at work and during off-job time to be negatively related to recovery, and higher levels of pleasure at work and during off-job time to be positively related to recovery. We also hypothesized that pleasure would act as a buffer against the negative effects of effort. Data were collected by means of a five-day diary study (three measurements daily, before and immediately after work, and at bedtime) among 120 university academic staff. Fatigue and (low) vigour were used as indicators of (lack of) recovery. Multilevel analyses showed that pleasure in the work and off-job domains had beneficial effects on recovery. An adverse association between effort expenditure and recovery was lacking. However, in the work domain, a combination of unpleasant and effortful work activities was negatively related to recovery. These findings stress the importance of engaging in pleasant activities during work and off-job time.     

价值导向的服务补救决策模型

着眼于企业成本控制,关注企业最优补救策略的决策机制设计。首先,基于顾客价值感知,将服务差错和服务补救系统进行了概念化建模;在此基础上以过程补救投入、结果补救投入和补救时机为决策变量,建立起企业服务补救决策的数学最优化模型;利用该模型,企业可以在满足顾客基本补救需求的约束条件下,制定出成本最优的补救策略。     

新型低合金高强度Cr-Mo钢热处理工艺研究

本文对一种Cr-Mo系的低合金结构钢进行了研究,通过对该新型的射孔枪管用钢进行完全淬火,研究了淬火温度、保温时间和回火温度对实验钢组织和性能的影响。研究结果表明,钢的晶粒随淬火温度的升高而增大,硬度先增大后减小;在相同的淬火温度下,随着保温时间的延长,钢的硬度和晶粒度变化不大;回火温度升高,钢的硬度和强度逐渐降低,断面收缩率和冲击功逐渐增大。当淬火温度为900 ℃保温时间为40 min、回火温度为560 ℃保温时间为80 min时,钢的屈服强度达到927 MPa,大于130 ksi,硬度达到31.2 HRC,同时纵横冲击功分别达到了74.5 J和119.7 J的水平,综合性能最优。     

Perspectives on How Social Business Can Engender Work Identity Among People with Mental Illness

ABSTRACT

Social businesses use market strategies to advance the employment and economic situation of people with mental illness who have experienced high levels of social marginalization. They have the potential to achieve these goals by fostering the work identity of the workers within the business, and to themselves acquire an identity as a viable commercial entity that contributes to the prosperity and social fabric of the local community. This study used in-depth case study methods enhanced by comparisons with international social businesses to understand the processes by which social businesses influence work identity. Six business processes that are salient to the development of a strong work identity were identified. Eight propositions for how work identity can be supported by social businesses are offered. The propositions may be useful as a guide for the development of social businesses that are organized and implemented to positively develop work identity, regardless of the nature of the business model.     

Academic Underachievement and Recovery: Student Perspectives on Effective Career Interventions

Academic achievement has a significant influence on various career development and decision‐making factors. Therefore, it is important for career counselors to understand how past academic underachievement affects students’ current lives and to develop interventions that might ameliorate negative effects. This study examined the experiences of 9 ethnically diverse college students who had experienced and overcome academic failure. Data were collected by individual interviews and analyzed based on the consensual qualitative research method. Four themes emerged in relation to participants’ academic underachievement and recovery: attitude, study strategies, external support, and coping difficulties. The results suggest that underachieving students are better able to cope with and overcome academic difficulties when they set clear career goals, use effective learning strategies, consciously put forth more effort, and receive external support.     

鹿三之死——《白鹿原》生态环境下的医学、心理学文化元素探讨

陈忠实先生的《白鹿原》被喻为建国以来"当代中国文学60年的巅峰之作",①在中国当代文学和陕西文坛上占有举足轻重的地位。其中长工鹿三之死的描写历来为读者所津津乐道。随着中国医疗和科技水平的不断发展,鹿三之死也就不仅仅是"鬼魂附体"所能自圆其说的。通过对鹿三患病的前后对比,探讨其病因在中医、西医及心理学方面的根据,从而发掘出《白鹿原》生态环境下的医学、心理学文化元素,积极彰显陈忠实先生在医学与心理学方面的丰博知识,使得鹿三形象趋于丰满和完美。