Optimal maintenance of systems with Markovian mission and deterioration

We consider the maintenance of a mission-based system that is designed to perform missions consisting of a random sequence of phases or stages with random durations. A finite state Markov process describes the mission process. The age or deterioration process of the system is described by another finite state Markov process whose generator depends on the phases of the mission. We discuss optimal repair and optimal replacement problems, and characterize the optimal policies under some monotonicity assumptions. We also provide numerical illustrations to demonstrate the structure of the optimal policies.     

关于提升电力运维人员投运培训水平的探讨

随着我国的用电需求不断提高,电力事业发展非常的快,为了适应社会的高需求,必须要努力提高服务的品质,确保电力能源安全、顺畅的输送.因此本文主要根据投运培训的定义和内涵,分析当下电力运维人员培训的现状,最后提出电力运维人员投运培训的有效途径和举措.     

LPVCD的原理与故障分析

文中介绍了CVD工艺的种类和特点。以LPVCD为例,介绍了其工艺的基本原理,以及设备的基本结构。根据多年的设备维护经验,分析了LPCVD设备的常见问题,提出了处理措施。最后,总结出了LPCVD设备的工艺维护方法。     

基于遗传算法的通信基站维护车辆调度问题研究

通信行业基站维护车辆的传统调度比较随意，日常维护没有全面的考虑到基站的次序和维护车辆行走路径的最小化问题。针对上述情况，借助遗传算法，提出一种由调度中心统一指挥，使代维公司多个驻点合理派发车辆，以最小路径和最佳次序遍历基站进行维护的方法。首先建立数学模型，然后根据模型的特点，采用整数排列编码，引入遗传算子，最后用MATLAB编程实现模型的求解。仿真结果验证了算法的可行性。     

Operation and maintenance field experience for off‐grid residential photovoltaic systems

The field performance of photovoltaic systems has been studied extensively for many applications and a number of databases exist in the United States and internationally. However, these databases focus almost exclusively on the system elecrical performance. Published information on the operation and maintenance (O&M) experience and costs for photovoltaic systems is almost nonexistent. At a time when photovoltaics is being considered as a viable option for distributed energy generation, it is critical that maintenance experience be captured to identify lifecycle costs and/or levelized energy costs for these systems, as well as to identify areas for system and component improvements. This paper addresses the data collection, analysis and results of an off‐grid residential customer service program offered by the Arizona Public Service (APS) Company over a six‐year period from 1997 through 2002. Standardized, packaged photovoltaic systems were offered and operated by APS through a lease arrangement with customers throughout the state of Arizona. The operation and maintenance records for these systems were carefully tracked and analyzed. The O&M costs, database development, cost drivers, lifecycle cost implications, and lessons learned are presented and discussed. Copyright © 2004 John Wiley & Sons, Ltd.     

共路信令(电话用户部分)跟踪结果的分析

共路信令特别适应未来通信业务的发展．与随路信令相比，有许多优点，已广泛应用于公众电话交换网、综合业务数字网、移动通信网、智能网和网络操作管理维护中。结合共路信令消息基本形式及常见消息格式的描述，对数字程控交换机之间共路信令(电话用户部分)的跟踪结果进行了分析，有助于提高维护人员对电信设备的维护能力。     

模糊决策在航空维修工程中的应用

本文以模糊数学和规划论为工具，对航空维修工程中一类决策问题的决策方法进行了探讨，给出了具有普遍意义的建模思想，通过实例分析，证明了这种方法的可行性和先进性。     

低温冷凝泵的结构和维护

分析了低温冷凝泵的工作原理和内部结构 ,并结合实际工作经验详细叙述了泵的维护和再生过程以及在电子束蒸发台上的应用     

Replicated Object Management with Periodic Maintenance in Mobile Wireless Systems

In this paper we analyze periodic maintenance strategies for managing replicated objectsin mobile wireless environments. Under periodical maintenancestrategies, the system periodically checks local cells to determineif a replicated object should be allocated or deallocated in a cell to reduce the access cost.We develop a performance model based on Petri netsthat considers the missing-read cost, write-propagationcost and the periodic maintenance cost with the objective to identify optimal periodic maintenance intervals to minimize theoverall cost. The analysis results show that the overall cost is highwhen the user arrival-departure ratio andthe read-write ratio work against each other and is low otherwise. In all cases, there exists an optimal periodic maintenance interval that would yield the minimum cost.Further, the optimal periodic maintenance interval increases as the arrival-departure ratio andthe read-write ratio work in harmony.