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.     

生产性服务业:发展态势、存在的问题及高质量发展政策思路

生产性服务业的改造提升和优化升级,是中国经济高质量发展的内在要求。当前,研发设计服务业“量质齐增”,已成为中国经济高质量发展的重要引擎；物流服务业发展迅猛,在企业生产和居民生活中的重要性日益凸显；金融服务业通过提供融资支持,有力促进了经济社会的良性发展；信息技术服务和电子商务飞速发展,“数字+”成为产业升级的重要实现渠道；租赁和商务服务业业态更加丰富,是促进产业转型升级的重要力量；服务外包规模持续攀升,业务覆盖范围不断扩展；职业教育方兴未艾,提升了中国人力资源的整体水平。但是,中国生产性服务业依然存在着国际竞争力羸弱、对外开放水平较低、与其他产业的融合力度不强、在全球价值链中的地位不高等问题。对此,提出了应进一步夯实生产性服务业发展的基础,对标国际标准推进服务业供给侧结构性改革,把生产性服务与制造业融合发展作为主攻方向,把提升服务贸易国际竞争力作为关键抓手,抓住机会提升生产性服务业全方位对外开放水平等政策建议。     

Quality management as a tool for job satisfaction improvement in low-level technology organizations: the case of Ethiopia

Human resources are an important determinant of operational performances as it is crucial for quality improvement. Research suggests that issues related to quality of work life of employees are often overlooked in low technology level organizations in the developing countries. This article aims to investigate the relationship between quality management (QM) practices and job satisfaction (JS) in relation with the Ethiopian manufacturing organizations. Data were collected using a structured survey questionnaire and face-to-face interviews of shop-floor workers. Exploratory and confirmatory factor analysis was used to validate the survey instrument and structural equation modelling was used for the analysis. The findings provide evidence that top management commitment, participation of employees and continuous improvement are significantly and positively associated with JS. However, customer focus has insignificant relationship and surprisingly, teamwork showed unexpected negative relationship with JS. The study provides important insights into the true worth of QM implementation in which it enforces the belief that its practices are the decisive factor in enhancing workplace satisfaction of employees.     

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。     

以服务基层为导向的全科医学人才培养模式的探索

当前，我国基层卫生技术人员队伍建设相对滞后，已经成为制约基层卫生机构发展的瓶颈。医学院校充分发挥人才培养职能，积极探索符合基层医疗服务特点的全科医生培养模式，对推动我国基层医疗卫生服务质量的提高，促进我国医药卫生体制改革的深化具有重要作用。本文对现阶段我国全科医学人才培养中存在的问题进行了分析，介绍了开展全科医学教育的重要意义，并结合辽宁医学院的工作实践，提出了以服务基层为导向的全科医学人才培养的建议和措施。     

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。     

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.     

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.     

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。     

Robust regression: an inferential method for determining which independent variables are most important

Consider the usual linear regression model consisting of two or more explanatory variables. There are many methods aimed at indicating the relative importance of the explanatory variables. But in general these methods do not address a fundamental issue: when all of the explanatory variables are included in the model, how strong is the empirical evidence that the first explanatory variable is more or less important than the second explanatory variable? How strong is the empirical evidence that the first two explanatory variables are more important than the third explanatory variable? The paper suggests a robust method for dealing with these issues. The proposed technique is based on a particular version of explanatory power used in conjunction with a modification of the basic percentile method.