基于QFD和TRIZ的战时装备维修流程设计需求分析模型

为适应未来高技术战争,需要对现有装备维修保障流程重新进行设计。针对此流程设计的重要工作——需求分析,建立了一种基于质量功能展开(QFD)和发明问题解决理论(TRIZ)的需求分析模型,提供了从作战任务需求到装备维修流程设计要求的需求变换方法,为后续的装备维修流程设计工作奠定了基础。     

基于马尔可夫决策过程的维修决策模型研究

提出了一种基于设备状况进行维修的模型.该模型包括随机失效和针对失效进行有计划检查、维修的过程.运用马尔可夫决策模型,提出了以费用-效果为指标的维修策略.     

嵌套移动网络路由优化技术研究

NEMO基本支持协议采用双向隧道,可以为移动网络中节点提供移动透明性支持,但是双向隧道技术存在明显的效率差的问题,尤其在嵌套移动网络(Nested NEMO)中更加明显.论文介绍了NEMO基本支持协议以及嵌套NEMO的模型.分析了NEMO路由优化问题现状,引入了路由优化概念,提出了一个针对嵌套NEMO的路由优化方案,并验证了方案的有效性.最后,给出了需要进一步研究的工作.     

联想S899t手机电路分析及维修方法

S899t手机是联想公司2012年推出的一款采用ST-Ericsson Nova AP9500应用处理器的新机型。该机型在市场上有一定的代表性,但关于该机型维修资料较少,作者在该款故障机的修理过程中对该机电路工作原理及维修方法进行了系统整理,文章将该机的电路分析及维修方法总结出来,供广大手机维修人员参考。     

Maintenance scheduling and staffing policies in a wafer fabricationfacility

We examine how to reduce the adverse effects of machine down time by prioritizing production equipment for attention by a limited number of maintenance personnel. The maintenance scheduling policies use system information to determine which machines are the most critical at a given time. This information includes repair times, queue lengths, due dates, available capacity, and steady-state utilizations. The effects of different staffing levels are also considered. A discrete-event simulation model of a wafer fabrication facility is used to examine the performance of the different policies. Results indicate that the choice of maintenance scheduling policy can significantly affect system performance under restrictive staffing-levels. Moreover, factory performance is shown to be sensitive to small changes in staffing level     

基于现场数据的地铁车辆牵引系统可靠性分析

牵引系统的可靠性对于地铁车辆的安全运行极为重要.文章结合某地铁线路的现场车辆检修记录,采用故障树法和蒙特卡洛法分析牵引系统的可靠性.首先,根据现场检修数据建立地铁牵引系统的故障树模型,并对所建立的故障树模型进行定性、定量分析.其次,运用蒙特卡洛法对地铁牵引系统进行可靠性仿真.最后,确定了牵引系统的薄弱环节和各部件的重要...     

风能资源评价及综合研究

风能作为一种可再生资源,是大自然对人类的馈赠。目前,利用风能的主要形式是风力发电。文中根据2016年全国大学生数学建模竞赛D题,对我国某风电场的现况进行了分析,通过建立数学模型来对该风电场的情况进行评估,并以停机维护造成经济效益损失最低为目标函数,引入0-1变量,建立最优化模型,用Lingo软件给出了均衡的排班方案和维护计划。     

一种计算可修复网络可用度的快速算法

对于可修复系统,其状态数随系统规模呈指数增长。文中在系统元件类型相同的假设条件下,以维修顺序为突破口剖析马尔可夫模型,证明在某几种维修顺序条件下,可由类状态概率来计算类状态中单个状态的概率;并以可修复网络系统为例提出了从类状态到不交和状态的映射算法,从而使计算网络可用度的复杂度大大降低。仿真结果表明合并策略和映射算法的正确。     

Power and rate control with outage constraints in CDMA wireless networks

A radio power control strategy to achieve maximum throughput for the up-link of CDMA wireless systems with variable spreading factor is investigated. The system model includes slow and fast fading, rake receiver, and multi-access interference caused by users with heterogeneous data sources. The quality of the communication is expressed in terms of outage probability, while the throughput is defined as the sum of the users' transmit rates. The outage probability is accounted for by resorting to a lognormal approximation. A mixed integer-real optimization problem P1, where the objective function is the throughput under outage probability constraints, is investigated. Problem P1 is solved in two steps: firstly, we propose a modified problem P2 to provide feasible solutions, and then the optimal solution is obtained with an efficient branch-and-bound search. Numerical results are presented and discussed to assess the validity of our approach.     

电视频道滤波器的小型化设计

阐述了螺旋滤波器的工作原理,分析了影响螺旋滤波器体积的因素,主要包括工作频率、插入损耗和数学模型,最后给出了电视20频道滤波器的小型化设计。     

基于半马尔科夫过程的变压器故障率预测及研究

设备的故障率曲线是制定维修策略的重要指标之一。为了合理估计变压器的故障率,本文提出了基于半马尔科夫过程的预测模型。模型中考虑了变压器的热老化过程和随机故障过程。热老化过程根据绝缘纸平均聚合度的取值范围划分为4个状态,状态间的转移时间假设服从威布尔分布,威布尔分布的尺度参数由经验公式获得;随机故障过程考虑了由雷击和短路冲击引起的2个随机故障状态,老化状态和随机故障状态之间的转移时间假设服从指数分布,转移率由故障统计数据获得。对模型中威布尔分布的形状参数进行适当取值后,可获得符合实际统计结果的变压器故障率曲线。     

数字电视工程管理数据挖掘模型设计与实践

分析了数字电视工程管理信息的特点,介绍了数字电视工程信息管理平台数据模型设计的整体思路,并针对工期延误原因的关联分析、多任务进度汇总的权重模型训练等重点问题进行了详细阐述。结论是,数字电视工程管理数据挖掘必须有一定的数据体系支持,对非结构化数据信息的整理是关键。     

ISO／IEC 29143移动RFtD空中接口协议分析

移动RFID网络中,读写器碰撞问题变得更加复杂.分析了ISO/IEC 29143移动RFID空中接口协议草案,重点研究了其读写器防碰撞机制,并与现有的一些防碰撞机制对比,为我国移动RFID技术的研究和标准化提出建议.     

Wireless and cellular architecture and services

Cellular architecture partitioning can improve the performance of telecommunications systems. The model proposed by the author allows for changing the cell size for different services and the number of users. The cell size that will ensure the best possible performance and quality of service can be derived by the model. The main task of a telecommunication system is call processing. This includes identifying incoming calls, establishing a communication path for the duration of the connection, and disconnecting the call after the conversation has ended. Call processing uses different components of the software architecture and involves processes and messages performing different functions and accessing various resources. In addition, the system requires administration and maintenance that also involves processes using different resources     

信息技术服务运维服务通用要求标准中之备件库应用

信息技术服务标准（Information Technology Service Standards,简称ITSS）是由国家标准化管理委员会、工业和信息化部等政府部门,以及中国电子工业标准化技术协会信息技术服务分会等行业组织发布的,以全面规范信息技术服务产品及其组成要素,指导实施标准化和可信赖信息技术服务的一系列标准,它包括咨询设计、集成实施、运行维护、服务管控、服务运营和服务外包等多个业务领域。在2012年11月5日,《信息技术服务标准运行维护第一部分：通用要求》等3项标准正式发布。《信息技术服务标准运行维护第一部分：通用要求》标准（以下简称通用要求）,提出了运维服务能力建设的通用模型,并在人员、资源、技术、过程等4个要素规定了运行维护提供商应具备的能力。     

浅析移动通信网垃圾短信的趋势和治理

通过挖掘目前四川联通移动通信网上的日常短信数据,分析垃圾短信的源头和趋势,建立了二维矢量模型并对大量群发号码进行过滤,尝试使用基于朴素贝叶斯算法的运营商策略和垃圾短信治理方案,在实际短信维护工作中取得了较好的效果。     

Decision support system for inspection and maintenance: a case study of oil pipelines

The existing method of pipeline health monitoring, which requires an entire pipeline to be inspected periodically, is unproductive. A risk-based decision support system (DSS) that reduces the amount of time spent on inspection has been presented. The risk-based DSS uses the analytic hierarchy process (AHP), a multiple attribute decision-making technique, to identify the factors that influence failure on specific segments and analyzes their effects by determining probability of occurrence of these risk factors. The severity of failure is determined through consequence analysis. From this, the effect of a failure caused by each risk factor can be established in terms of cost and the cumulative effect of failure is determined through probability analysis. The model optimizes the cost of pipeline operations by reducing subjectivity in selecting a specific inspection method, identifying and prioritizing the right pipeline segment for inspection and maintenance, deriving budget allocation, providing guidance to deploy the right mix labor for inspection and maintenance, planning emergency preparation, and deriving logical insurance plan. The proposed methodology also helps derive inspection and maintenance policy for the entire pipeline system, suggest design, operational philosophy, and construction methodology for new pipelines.     

Quality-oriented-maintenance for multiple interactive tooling components in discrete manufacturing processes

In discrete manufacturing processes such as stamping, assembly, or machining processes, product quality, often defined in terms of the dimensional integrity of work pieces, is jointly affected by multiple process variables. During the production phase, the states of tooling components, which are measured by adjustable process variables, are subject to possible random continuous drifts in their means & variances. These drifts of component states may significantly deteriorate product quality during production. Therefore, maintenance of the tooling components with consideration of both their continuous state drifts as well as catastrophic failures is crucial in assuring desired product quality & productivity. In contrast to traditional maintenance models where product quality has not been well addressed, especially for discrete manufacturing processes, a general quality-oriented-maintenance methodology is proposed in this paper to minimize the overall production costs. In this research, the total production cost includes product quality loss due to process drifts, productivity loss due to catastrophic failures, and maintenance costs. The quality-oriented-maintenance model is built based on a response model linking process variables with multidimensional product quality. It can be obtained either from engineering analysis for specific processes, or from statistical design of experiments. Three typical multi-component maintenance models are investigated under the general quality-oriented-maintenance framework. A case study for a sheet-metal stamping process is presented to demonstrate the effectiveness of the proposed methodology.     

一种双向HFC网射频指标评价新方法的探讨

对全网的CM射频数据进行统计学分析,通过对指标的均值偏移与波动情况研究,得出一种简单、有效、实时的评测双向HFC射频性能的模型,对HFC的运行维护、监督管理具有很好的借鉴意义.