The accelerated hazard model in survival analysis assumes that the covariate effect acts the time scale of the baseline hazard rate. In this paper, we study the stochastic properties of the mixed accelerated hazard model since the covariate is considered basically unobservable. We build dependence structure between the population variable and the covariate, and also present some preservation properties. Using some well-known stochastic orders, we compare two mixed accelerated hazards models arising out of different choices of distributions for unobservable covariates or different baseline hazard rate functions. 相似文献
The conversion of a hukou (household registration) from one locale to another in China requires official approval, a process subject to conditions set out in numerous regulations. This article examines the role of points systems for selecting economic migrants eligible for an urban hukou in several provinces. Using the points systems, city governments prioritize human resources and capital, which they consider to be the key to economic prosperity, over social objectives. Meanwhile the majority of migrants, who participate in urban employment without official registration, are treated as necessary contributors to the economy but not as qualified beneficiaries of it. It remains to be seen, with a wider application of points systems in more Chinese cities, whether the hukou system will evolve to make urban citizenship less exclusive and more equitable. The article provides detailed examples, at the province and city level, of rating schemes for qualifying for an urban hukou. 相似文献
Waste stemmed from inappropriate quality control and excessive inventories is a major challenge for perishable food management in grocery retail chains. Improvement of visibility and traceability in food supply chains facilitated by tracking and tracing technologies has great potential to improve operations efficiency. This research aims to reduce food spoilage waste and maximise food retailer's profit through a pricing approach based on dynamically identified food shelf life. The proposed model is evaluated through different pricing policies to exploit the benefits from utilising accurate product shelf life information captured through innovated tracking and monitoring technologies. Numerical analysis is conducted in an illustrative case study. 相似文献
The negative effect of work-leisure conflict has attracted the attention of researchers. However, no previous research has determined the relationship between work-leisure conflict and ego depletion. Therefore, this study explores the relationship between daily work-leisure conflict and ego depletion, as well as the role of individuals’ negative emotions and core self-evaluations in this process based on ego depletion theory. Through the method of daily diary research, 77 employees were tracked for 7 consecutive work days. The results show that work-leisure conflict is positively related to employee ego depletion, that the negative emotions play a mediating role in this relationship and that core self-evaluations moderate the indirect effect of work-leisure conflict on ego depletion through negative emotions. In this study, daily diary method is used to verify the dynamic characteristics of work-leisure conflict, negative emotions and ego depletion, and some new insights into how to reduce employee ego depletion are provided.