Availability analysis for general repairable systems with repair time threshold

Availability analysis is an important issue in many practical fields. This paper investigates the availability for general repairable systems with repair time threshold. Based on practical applications, a repair time threshold is introduced. If the period of a repair is less than a predefined time threshold, then the system may be considered as working during this period, i.e., the effect of the repair could be neglected. Otherwise, if the period of a repair is longer than the given threshold, then the system is considered as working from the beginning of the system failure until the repair time exceeding the threshold, i.e., the time point of the system down could be delayed. We consider both constant and random repair time threshold. This paper valuates the user-perceived availability, when the user does not experience any service interruption because the duration of repair is too short. The results can be applied in reliability engineering, queueing theory and many other fields. A numerical example for ventilator system is presented to demonstrate the application of the developed approach.     

Computational analysis of the queue with working breakdowns and delaying repair under a Bernoulli-schedule-controlled policy

This paper considers a single server queueing system with working breakdowns and delaying repair under a Bernoulli-schedule-controlled policy. At a breakdown instant, the system either goes to repair period immediately with probability p, or continues to provide auxiliary service for the current customers with probability q = 1 ? p. While the system resides in the auxiliary service period, it may go to repair period if there is no customer at the epoch of service completion or the occurrence of breakdown. By using the matrix analytic method and the spectral expansion method, we respectively obtain the steady state distribution to make the straightforward computation of performance measures and the Laplace-Stieltjes transform of the stationary sojourn time of an arbitrary customer. In addition, some numerical examples are presented to show the impact of parameters on the performance measures.     

Diagnostics for the diagnostics

Abstract

This paper examines the tendency towards income convergence among China's main provinces during the two periods: the pre‐reform period 1953–1977 and the reform period 1978–1997 using the framework of the Solow growth model. The panel data method accounts for not only province‐specific initial technology level but also the heterogeneity of the technological progress rate between the fast‐growing coastal and interior provinces. Estimation problems of weak instruments and endogeneity are addressed by the use of a system generalized method of moments (GMM) estimator. The main empirical finding is that there is a system‐wide income divergence during the reform period because the coastal provinces do not share a common technology progress rate with the interior provinces.     

Performance analysis of machine repair system with single working vacation

Abstract

This paper studies a machine repair problem with repairman’s single working vacation in which repairman works with a lower repair rate rather than completely terminating repair during vacation period. Employing Markov process theory and matrix analytical method, various system performance measures are obtained in transient and stationary regimes. Moreover, we deduce the system reliability, the mean time to failure, the repairman’s busy period and the waiting time of failed machine by using the probabilistic properties of phase type distribution. Further, some numerical examples are provided. Finally, a cost model is developed to determine the optimum value of operating machines.     

基于典型相关分析的3E系统协调度评价研究

"十二五"时期既是中国实现工业化的关键时期,也是转变经济结构、提高城市化水平、优化居民消费结构、改善环境与公众健康的重要阶段,这都需要以能源-经济-环境(3E)系统协调发展为保证。因此,在典型相关分析的基础上建立3E系统协调度评价模型,并利用其对中国29个省市区的3E系统协调度进行综合评价,实证结果表明:河北、广东等13个省市区处于中度失调状态;北京、上海等16个省市区呈轻度失调状态。     

An M/G/1 clearing queueing system with setup time and multiple vacations for an unreliable server

This paper studies an M/G/1 clearing queueing system with setup time and multiple vacations, in which all present customers in the system are served simultaneously and breakdowns may occur in busy or setup period. We investigate the stationary distribution of system size and the Laplace–Stieltjes transform of sojourn time. In addition, various performance measures are discussed, such as the mean system size at arbitrary time and the mean length of a vacation circle. Moreover, a cost analysis is carried out for this queueing system. Numerical results are presented to study the sensitivity of the system parameters on the expected cost function and system performances.     

Percentile-t Bootstrap Confidence Intervals for Period Using Periodogram

The magnitude of light intensity of many stars varies over time in a periodic way. Therefore, estimation of period and making inference about this parameter are of great interest in astronomy. The periodogram can be used to estimate period, properly. Bootstrap confidence intervals for period suggested here, are based on using the periodogram and constructed by percentile-t methods. We prove that the equal-tailed percentile-t bootstrap confidence intervals for period have an error of order n ^?1. We also show that the symmetric percentile-t bootstrap confidence intervals reduce the error to order n ^?2, and hence have a better performance. Finally, we assess the theoretical results by conducting a simulation study, compare the results with the coverages of percentile bootstrap confidence intervals for period and then analyze a real data set related to the eclipsing system R Canis Majoris collected by Shiraz Biruni Observatory.     

Provincial Conditional Income Convergence in China, 1953-1997: A Panel Data Approach

This paper examines the tendency towards income convergence among China's main provinces during the two periods: the pre-reform period 1953-1977 and the reform period 1978-1997 using the framework of the Solow growth model. The panel data method accounts for not only province-specific initial technology level but also the heterogeneity of the technological progress rate between the fast-growing coastal and interior provinces. Estimation problems of weak instruments and endogeneity are addressed by the use of a system generalized method of moments (GMM) estimator. The main empirical finding is that there is a system-wide income divergence during the reform period because the coastal provinces do not share a common technology progress rate with the interior provinces.     

改革开放后中国政府效率改进的数量分析

把政府视为联合供给公共品的组织,根据政府供给的主要公共品建立复合指标体系,采用DEA模型中的MPI指数计算改革开放以来中国政府效率的改进状况,结果显示：绝大多数年份中中国政府效率都不断得到高速改进,平均改进速度甚至超过同期中国GDP增长率。结果表明：中国现行政府体制存在相对有效的自我完善机制,中国政府改革的主要方向是符合当前发展阶段的要求的。在数量分析的基础上,提出中国政府进一步改革可能需要重点关注的方面。     

失业风险监测预警指标体系研究

随着社会主义市场经济体制改革的深化,失业在中国已成为一种不可避免的社会现象和突出的社会矛盾。然而在社会保险水平有限,劳动者和社会对高失业风险承受能力有限的情况下,为了配合改革,确保经济发展和社会稳定,有必要建立一套可行的失业风险监测预警运行系统,以便...