• Journal of the Korean Data and Information Science Society
• /
• v.17 no.2
• /
• pp.367-377
• /
• 2006

This paper develops a periodic preventive maintenance(PM) policy following the expiration of warranty. Two types of warranty are considered: renewing warranty and non-renewing warranty. Also, we consider the situation where each PM cost is an increasing function of the PM effect. We determine the optimal number of PM's before replacing the system by a new one and the optimal length of period for the periodic PM following the expiration of warranty. Explicit solutions to determine the optimal periodic PM are presented for the Weibull distribution case.

• Journal of the Korean Society for Library and Information Science
• /
• v.26
• /
• pp.235-256
• /
• 1994

The purpose of this paper is to review concerns and activities related to the library of Germany as well as to look over recent trends referred to the maintenance of the library and its information service system since the unification of Germany in 1990. In fact, since the unification, many libraries in old East Germany have been closed with some precious books being lost. Also since most of libraries are short of funds and proper materials, it is real situation that they can not actively respond to the demand of information by library users who want to adapt themselves to changes, while only urgently requesting some support from old West Germany. In the meantime, the new government and libraries of Germany are giving a great effort to building an efficient document delivery system through financial support for the expansion of books and the purchase of urgently necessary library equipments in the poor libraries of old East Germany and support for the course to re-educate the in-service or unemployeed librarians, and also systematic organization between similar libraries, integration of national bibliographies, and maintenance of the interlibrary loan system. The nationwide interlibrary loan system, an expanded form of the system of old West Germany, allows the delivery of document to be easily performed, centered on both central cataloues for East Germany and West. However, in order to build an efficient information service system which covers whole Germany, it seems there needs more time required.

• Proceedings of the KSR Conference
• /
• 2003.10c
• /
• pp.252-257
• /
• 2003

It is necessary to have a maintenance of track and its equipment for safety and s the railroad transportation. In the paper, we examine the safety problems, protecti and composition of protection system for safety within the track which RTRI develo system consists of a mobile business tool carried by each worker. a terminal of t platform temporarily installed in the maintenance car. a connector attached to signalling system and a central administrative device installed at the control cen used independently to detect positions of workers and maintenance cars. Each m correctly grasp the geometrical relations with other workers cars and other objects conditions based on the state information exchanged between the machines by the control protocol. the track occupancy monitor information broadcast by th administrative device and the line information. The protection system executes its f this basic structure.

• Journal of Construction Engineering and Project Management
• /
• v.4 no.3
• /
• pp.21-32
• /
• 2014

The practiced conventional methods for maintenance management in Malaysian Polytechnic faced many issues due to poor service delivery, inadequate finance, poor maintenance plan and maintenance backlogs. The purpose of this study is to improve the conventional method practices which tend to be ineffective in Malaysian Polytechnic. The case studies were conducted with eight Polytechnics and are selected based on conventional method practices and its major problems. There are around 32 Polytechnics in Malaysia and almost are using conventional methods. The number is considered very big indicating that the use of modern Information and Communication Technology (ICT) is still very limited compared to other institutions of higher learning in Malaysia. The overall findings of this research indicated; poor service delivery, inadequate financial, poor maintenance planning and maintenance backlogs. There is also need to overcome less man power competencies of maintenance management practices which existed with all eight Polytechnics. The proposed system is intended to be used for maintenance management practices at Malaysian Polytechnics in order to provide high-quality of building facility with safe and healthy environments.

• Journal of Ocean Engineering and Technology
• /
• v.28 no.6
• /
• pp.533-539
• /
• 2014

A maintenance system for an offshore plant uses an optimal maintenance method, process, and period based on operation information data and economic evaluation techniques. Maintenance is performed after one or more indicators show that equipment is going to fail or that equipment performance is deteriorating. A maintenance system is based on the use of real-time data to prioritize and optimize the LNG-FPSO topside equipment resources.

• Proceedings of the KSR Conference
• /
• 2004.10a
• /
• pp.886-891
• /
• 2004

The process of determining whether, when, where and how to intervene, of deciding on optimum allocation of resources and minimizing the cost is a very complex problem: different track sections tend to behave differently under the effects of loading; decision-making processes for maintenance work are closely interrelated technically and economically; decision-making for maintenance plans is based on a large quantity of technical and economic information, extensive knowledge and above all experience. For that reason, It is considered very important to develope objective and computer-aided decision-making support system for track maintenance plan. On this paper, we made a survey of the state-of-art of decision-making support systems for track maintenance which were developed and used abroad and reviewed requirements of system and present the plan of develope decision-making support system for track maintenance appropriate to local condition.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.58 no.3
• /
• pp.276-284
• /
• 2009

In this paper, we develop the image transfer remote maintenance monitoring system for hand held device which can compensate defects of human mistake. The human mistakes always happen when the worker communicate information each other to check and maintenance the equipment of the power plant under bad circumstance such as small place and long distance in power plant. A worker couldn't converse with other when in noisy place like Power plant. So, we make some hand device for handy size and able to converse in noisy place. The developed system can have improvement of productivity through increasing plant operation time. And developed system is composed of advanced H/W(hard ware) system and S/W(soft ware)system. The H/W system consist of media server unit, communication equipment with hand held device, portable camera, mike and head set. The advanced s/w system consist of data base system, client pc(personal computer) real time monitoring system which has server GUI(graphic user interface) program, wireless monitoring program and wire ethernet communication program. The client GUI program is composed of total solution program as pc camera program, and phonetic conversation program etc.. We analyzed the required items and investigated applicable part in the image transfer remote maintenance monitoring system with hand held device. Also we investigated linkage of communication protocol for developed prototype, developed software tool of two-way communication and realtime recording skill of voice with image. We confirmed the efficiency by the field test in preventive maintenance of plant power.

• Asia pacific journal of information systems
• /
• v.8 no.1
• /
• pp.43-64
• /
• 1998

Cooperative query answering is a research effort to develop a fault-tolerant and intelligent database system using the semantic knowledge base constructed from the underlying database. Such knowledge base has two aspects of usage. One is supporting the cooperative query answering process for providing both an exact answer and neighborhood information relevant to a query. The other is supporting ongoing maintenance of the knowledge base for accommodating the changes in the knowledge content and database usage purpose. Existing studies have mostly focused on the cooperative query answering process but paid little attention to the dynamic knowledge base maintenance. This paper proposes a multi-level knowledge representation framework called Knowledge Abstraction Hierarchy(KAH) that can not only support cooperative query answering but also permit dynamic knowledge maintenance, On the basis of the KAH, a knowledge abstraction database is constructed on the relational data model and accommodates diverse knowledge maintenance needs and flexibly facilitates cooperative query answering. In terms of the knowledge maintenance, database operations are discussed for the cases where either the internal contents for a given KAH change or the structures of the KAH itself change. In terms of cooperative query answering, four types of vague queries are discussed, including approximate selection, approximate join, conceptual selection, and conceptual join. A prototype system has been implemented at KAIST and is being tested with a personnel database system to demonstrate the usefulness and practicality of the knowledge abstraction database in ordinary database application systems.

• Journal of the Korea Society of Computer and Information
• /
• v.27 no.1
• /
• pp.51-59
• /
• 2022

As the weapon system's dependence on software functions increased, software became a key factor in controlling the weapon system. In addition, as software development becomes more important domestically and internationally, software verification becomes an issue. The recent defense market has recognized this point and is demanding a plan for weapon system software maintenance. In this paper, we propose a weapon system software maintenance plan using Automatic Test Equipment. The specific method is to use a simulator to check the software function and identify failure cases. This is an effective way for developers to reduce the Total Corrective Maintenance Time(TCM) of the weapon system by reducing the time it takes to identify failure cases. It has been proven that the proposed Automatic Test Equipment can achieve software maintenance and excellent Maintainability and Operational Availability compared to the existing ones.

• Journal of The Korean Digital Architecture Interior Association
• /
• v.9 no.2
• /
• pp.25-33
• /
• 2009

So far we have investigate and analyzed the actual conditions of building maintenance in Korea and compared the building maintenance laws and systems between Korea and other countries. Now, based on the results from such comparison and analysis, this study proposes the following ideas for improvement: 1) As we can learn from domestic and foreign case studies, in the existing built-up areas becoming obsolete, many building owners remodel their buildings illegally in reaction to current economic and social changes. Therefore, for efficient maintenance of buildings, it is required to improve building maintenance systems by formulating information about inspection items, inspectors, supervisors, inspection costs and intervals of reporting results, depending on how large the buildings are and what they are used for. 2) In addition, to ensure the success of a building maintenance system, it is necessary to keep and manage a history of building maintenance thoroughly and introduce a certification program which gives an appropriate grade to maintenance performance and commits the government to expand their public roles and supporting policies, as widely used in some foreign countries. Further, in keep the building maintenance system secure, there should be a nationwide consensus as well as a favorable evaluation from building owners and manager, and all related people.