Inference and optimal design of multiple constant-stress testing for generalized half-normal distribution under type-II progressive censoring

The generalized half-normal (GHN) distribution and progressive type-II censoring are considered in this article for studying some statistical inferences of constant-stress accelerated life testing. The EM algorithm is considered to calculate the maximum likelihood estimates. Fisher information matrix is formed depending on the missing information law and it is utilized for structuring the asymptomatic confidence intervals. Further, interval estimation is discussed through bootstrap intervals. The Tierney and Kadane method, importance sampling procedure and Metropolis-Hastings algorithm are utilized to compute Bayesian estimates. Furthermore, predictive estimates for censored data and the related prediction intervals are obtained. We consider three optimality criteria to find out the optimal stress level. A real data set is used to illustrate the importance of GHN distribution as an alternative lifetime model for well-known distributions. Finally, a simulation study is provided with discussion.     

医疗信息共享对患者转移数量和服务质量水平影响研究

当前我国医院间存在严重的"信息孤岛"，医院参与医疗信息共享意愿不高，患者的诊疗信息被静态碎片化储存而无法充分有效地利用。考虑到医院进行医疗信息共享将降低患者转移成本，本文构建一个多阶段双寡头动态博弈模型研究医疗信息共享对医院竞争过程中患者转移数量和服务质量水平决策的影响。首先，根据是否存在转移成本，将患者分为新患者和经验性患者，借助Hotelling模型刻画患者的效用函数，分析患者就诊决策。然后，在政府价格规制和不考虑医院利他性情景下，构建了医院累积期望收益目标函数，使用动态规划方法，求解实现医院累积期望收益最大化的服务质量水平，获得了实现患者相互转移且医院在市场中共存的马尔可夫完美均衡。最后，根据医院参与医疗信息共享后患者转移成本降为零，分析与比较信息共享前后患者转移数量和服务质量水平变化。研究发现：在不同医院间本身存在患者转移背景下，医院参与信息共享后，患者转移数量增加但存在一个上限，增加的转移量与患者在医院间的转移成本呈正相关，与初始感知效用的差值范围呈负相关；医院参与信息共享后，均衡状态下的医院服务质量水平高于信息共享前的服务质量水平。因此，在不改变当前医保支付方式下，要加快推进医疗信息共享，政府部门可以根据医院的患者数量和服务质量水平变化对其进行定期补贴，以激励医院积极参与医疗信息共享，本文给出了这个补贴的量化表达。     

需求率受推广努力水平影响的新能源汽车租赁系统协调契约

考虑由新能源汽车租赁企业和政府组成的二级系统，在需求率为随机且与推广努力水平相关的市场环境下，建立了新能源汽车租赁企业和政府之间的博弈模型，探讨了分散决策、集中决策、收益共享与成本共担契约下的最优车队配置和推广努力水平，并对三种情形下的最优决策进行了比较和分析。研究结果表明：在分散决策情况下无法实现系统协调，通过引入成本共担与收益共享组合契约，当契约参数满足一定条件时，该组合契约模型不仅可以实现系统协调而且可以使系统成员达到帕累托改进。最后通过算例分析，验证了模型了可靠性和有效性。     

城市公共艺术与文化软实力的对接关系研究——以广州为例

文化软实力是一个国家除军事经济之外让别人主动接近的吸引力,城市公共艺术也是一种与大众有亲缘关系的艺术形态。某种程度上说,城市公共艺术是文化软实力在艺术领域的一种显象。广州城市公共艺术在器物层、行为层、制度层诠释了文化软实力的静态和动态的维度。     

Toward an Application Guide for Safety Integrity Level Allocation in Railway Systems

The work in the article presents the development of an application guide based on feedback and comments stemming from various railway actors on their practices of SIL allocation to railway safety‐related functions. The initial generic methodology for SIL allocation has been updated to be applied to railway rolling stock safety‐related functions in order to solve the SIL concept application issues. Various actors dealing with railway SIL allocation problems are the intended target of the methodology; its principles will be summarized in this article with a focus on modifications and precisions made in order to establish a practical guide for railway safety authorities. The methodology is based on the flowchart formalism used in CSM (common safety method) European regulation. It starts with the use of quantitative safety requirements, particularly tolerable hazard rates (THR). THR apportioning rules are applied. On the one hand, the rules are related to classical logical combinations of safety‐related functions preventing hazard occurrence. On the other hand, to take into account technical conditions (last safety weak link, functional dependencies, technological complexity, etc.), specific rules implicitly used in existing practices are defined for readjusting some THR values. SIL allocation process based on apportioned and validated THR values is finally illustrated through the example of “emergency brake” subsystems. Some specific SIL allocation rules are also defined and illustrated.     

居民养老保险:参保主体、筹资与待遇水平

本文从参保结构、筹资水平和待遇水平等3个方面对城乡居民养老保险制度进行了分析。研究发现,在参保结构方面,伴随着城镇化率的提高,居民养老保险参保人数的相对比例在下降;在筹资水平方面,个人缴费水平过低,其主要原因是财政补贴资金激励性不足,从而需要在进一步提高财政补贴的同时,优化补贴结构,提高对个人缴费的激励作用;在待遇方面,居民养老金总体水平较低、但增长幅度较大,与职工待遇相比,替代率的差距要远远小于绝对额的差距。     

Age limits for participation in child protection court proceedings in Sweden

According to the UN Convention on the Rights of the Child and Swedish legislation, children have the right to participate in child protection proceedings. The aim of this paper is to describe and analyse the notion of age and maturity in child protection proceedings in order to elucidate how these aspects could influence children's rights to participate. We focus on the view of three groups of actors involved in child protection proceedings in Sweden—social workers, lawyers, and laypersons in social welfare boards and administrative courts—and on how children's age and maturity should be taken into consideration in decisions on their participation in court. The analysis is based on survey data. The study found that social workers, laypersons, and lawyers have different views on when children are old enough to have the right to litigate in court. Additionally, there is no consensus on how the maturity of the child can be assessed to inform the decision about participation. More discussion is needed about what competences a child needs to participate in court and to what extent this right should be limited by their age. Importantly, courts and decision‐making proceedings can be made more child friendly.     

Designing an economically optimal repetitive group-sampling plan based on loss functions

Acceptance sampling is a quality assurance tool, which provides a rule for the producer and the consumer to make acceptance or rejection decision about a lot. This paper attempts to develop a more efficient sampling plan, variables repetitive group sampling plan, based on the total loss to the producer and consumer. To design this model, two constraints are considered to satisfy the opposing priorities and requirements of the producer and the consumer by using Acceptable quality level (AQL) and Limiting quality level (LQL) points on operating characteristic (OC) curve. The objective function of this model is constructed based on the total expected loss. In order to illustrate the application of the proposed model, an example is presented. In addition, the effects of process parameters on the optimal solution and the total expected loss are studied by performing a sensitivity analysis. Finally, the efficiency of the proposed model is compared with the variables single sampling plan, the variables double sampling plan and the repetitive group sampling plan of Balamurali and Jun (2006) in terms of average sample number, total expected loss and its difference with ideal OC curve.     

Level of choice in older women’s decisions to retire or continue working and associated well-being

Retirement is a complex life transition. Women’s retirement, like their work lives, may be further complicated, for example, by family or financial obligations; they may feel forced to retire or to continue working or feel they have the choice to do so. This study examines the role of voluntary versus involuntary retirement or continued work participation among retirement-age women; specifically, the relationships between choice, work status, and well-being. Compared to women forced to retire, women who chose retirement or continuing to work had higher levels of life satisfaction. Findings highlight the importance of examining retirement within the life course context.     

Optimal design of repetitive group sampling plans for Weibull and gamma distributions with applications and comparison to the Birnbaum–Saunders distribution

In this paper, we propose a multiple deferred state repetitive group sampling plan which is a new sampling plan developed by incorporating the features of both multiple deferred state sampling plan and repetitive group sampling plan, for assuring Weibull or gamma distributed mean life of the products. The quality of the product is represented by the ratio of true mean life and specified mean life of the products. Two points on the operating characteristic curve approach is used to determine the optimal parameters of the proposed plan. The plan parameters are determined by formulating an optimization problem for various combinations of producer's risk and consumer's risk for both distributions. The sensitivity analysis of the proposed plan is discussed. The implementation of the proposed plan is explained using real-life data and simulated data. The proposed plan under Weibull distribution is compared with the existing sampling plans. The average sample number (ASN) of the proposed plan and failure probability of the product are obtained under Weibull, gamma and Birnbaum–Saunders distributions for a specified value of shape parameter and compared with each other. In addition, a comparative study is made between the ASN of the proposed plan under Weibull and gamma distributions.