Imperfect preventive maintenance for numerical control machine tools with log-linear virtual age process

Based on the log-linear virtual age process, an imperfect preventive maintenance policy for numerical control（NC）machine tools with random maintenance quality is proposed. The proposed model is a combination of the Kijima type virtual age model and the failure intensity adjustment model. Maintenance intervals of the proposed hybrid model are derived when the failure intensity increase factor and the restoration factor are both random variables with uniform distribution. The optimal maintenance policy in infinite time horizon is presented. A numerical example is given when the failures of NC machine tools are described by the log-linear process. Finally, a discussion is presented to show how the optimal results depend on the different cost parameters.     

油库防爆电气设备的维修管理

结合防爆电气设备的原理及对防爆电气设备的基本要求，指出了防爆电气设备在维修中应当注意的有关事项和容易忽的一些问题。     

Case-Base Maintenance in a Multimodal Reasoning System

The definition of suitable case-base maintenance policies is widely recognized as a major key to success for case-based systems; underestimating this issue may lead to systems that either do not fulfill their role of knowledge management and preservation or that do not perform adequately under performance dimensions, namely, computation time and competence and quality of solutions. The goal of this article is to analyze some automatic case-base management strategies in the context of a multimodal architecture combining case-based reasoning and model-based reasoning. We propose and compare two different methodologies, the first one, called replace , is a competence-based strategy aimed at replacing a set of stored cases with the current one, if the latter exhibits an estimated competence comparable with the estimated competence of the considered set of stored cases. The second one, called learning by failure with forgetting (LFF), is based on incremental learning of cases interleaved with off-line processes of forgetting (deleting) cases whose usage does not fulfill specific utility conditions. Results from an extensive experimental analysis in an industrial plant diagnosis domain are reported, showing the usefulness of both strategies with respect to the maintenance of suitable performance levels for the target system.     

对职业院校模具预备技师人才培养的思考

从技师的能力目标出发，就技师培养的模式和课程作了一些思考，一是缓解技师培养的燃眉之急，二是寻找技师培养的最佳途径。     

A framework for the development of videogames

A framework is a high‐level solution for the reuse of software pieces, a step forward in simple library‐based reuse, that allows the sharing of not only common functions but also the generic logic of a domain application. It also ensures a better level of quality for the final product, given the fact that an important fraction of the application is already found within the framework and has therefore already been tested. This case study takes the systematic generation of hot‐spot subsystems approach as a reference point to describe the underlying concepts in the design of a framework for the development of 2D action videogames for low‐performance machines. The main goal of this paper is to show the applicability of framework‐based reuse to videogames. Both standard and framework‐based game implementations are compared and the results are analysed. Special attention is paid to the (potential) benefits that the use of frameworks brings to the fulfillment of maintenance tasks along the game's life cycle, a stage that normally consumes most resources in software projects. At the end of the paper, based on the implementation results, this study shows the predicted conditions under which building a framework is cost effective for the development of videogames similar to the ones from the studied domain. Copyright © 2001 John Wiley & Sons, Ltd.     

300kt/a甲醇装置的操作及维护

介绍了中原甲醇厂的以天然气为原料的30万t/a甲醇装置的操作和维护经验。     

井式炉的结构和维护方法

介绍球化退火井式炉的基本结构,对自预热燃烧器的结构和工作原理进行详述。提出设备重要部件如内筒及对流筒、炉底搅拌风扇、温控和电控系统维护过程中需要注意的问题。在井式炉使用过程中除了检查循环冷却水、炉底搅拌风扇、气氛压力、炉体密封、热电偶等是否正常外,应及时对甲醇裂解炉和甲醇裂解气管道进行除炭。在使用和维护时,应及时检查炉体的密封状况和设备机械传动件的润滑情况,控制进炉物料数量,保证井式炉工艺稳定。     

硬盘常见故障及一般维修方法

随着计算机技术的迅猛发展,硬盘的容量和速度也在飞速增长,但由于硬盘工作原理的制约,其安全性和稳定性却一直没有明显的改善,脆弱的硬盘稍有不慎就会出现这样那样的故障,威胁着其存储数据的安全。但只要我们掌握一些常用的维修方法,就可以排除一些常见故障而使硬盘继续正常工作,该文就此进行一些探讨。     

谈清香型大曲酒生产如何创新控酸保醅

酿酒生产过程中，为防止酒醅材料太酸，要求在过程中采取各种手段进行控制酸度。这成为贯穿整个生产过程的非常关键的技术要领，根据气候季节的变化，调整时间安排、控制入温、控制水分都是有效控制材料生酸的办法。只有这样，才能有效提高出酒率。     

利用轨检车检测资料指导现场维修

介绍了国内外轨检车的情况及轨道动态质量指标TQI,分析了轨检车波形图及检测数据,探讨了科学合理的轨道动态检测评价体系的建立,以更好地利用轨检车资料指导日常线路养护维修工作。