• Journal of the Korean Society of Safety
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• v.21 no.4 s.76
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• pp.25-32
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• 2006

LonWorks over IP(LonWorks-IP) virtual device network(VDN) is an integrated form of LonWorks device network and IP data network. In especially real-time distributed servo applications on the factory floor, timely response is essential for predictive and preventive maintenance. The time delay in servo control on LonWorks-IP based VDN has highly stochastic nature. LonWorks-IP based VDN induced transmission delay deteriorates the performance and stability of the real-time distributed control system and can't give an effective preventive and predictive maintenance. In order to guarantee the stability and performance of the system, and give an effective preventive and predictive maintenance, LonWorks-IP based VDN induced time-varying uncertain time delay needs to be predicted and compensated. In this paper new Pill control scheme based on Smith predictor, disturbance observer and band pass filter is proposed and tested through computer simulation about position control of DC servo motor. It is shown that how can the proposed control scheme be designed to minimize the effects of uncertain varying time delay and model uncertainties. The validity of the proposed control scheme is compared and demonstrated with the comparison of internal model controllers(IMC) based on Smith predictor with and without disturbance observer.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.4
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• pp.12-23
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• 2014

The O&M (Operation and Maintenance) phase of offshore plants with a long life cycle requires heavy charges and more efforts than the construction phase, and the occurrence of an accident of an offshore plant causes catastrophic damage. So previous studies have focused on the development of advanced maintenance system to avoid unexpected failures. Nowadays due to the emerging ICTs (Information Communication Technologies) and sensor technologies, it is possible to gather the status data of equipment and send health monitoring data to administrator of an offshore plant in a real time way, which leads to having much concern on the condition based maintenance policy. In this study, we have reviewed previous studies associated with CBM (Condition-Based Maintenance) of offshore plants, and introduced an algorithm predicting the next failure time of the compressor which is one of essential mechanical devices in LNG FPSO (Liquefied Natural Gas Floating Production Storage and Offloading vessel). To develop the algorithm, continuous time Markov model is applied based on gathered vibration data.

• Journal of the Korean Society of Safety
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• v.38 no.5
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• pp.43-50
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• 2023

With the advent of industrialization, consumers and end-users demand more reliable products. Meeting these demands requires a comprehensive approach, involving tasks such as market information collection, planning, reliable raw material procurement, accurate reliability design, and prediction, including various reliability tests. Moreover, this encompasses aspects like reliability management during manufacturing, operational maintenance, and systematic failure information collection, interpretation, and feedback. Improving product reliability requires prioritizing it from the initial development stage. Failure mode and effect analysis (FMEA) is a widely used method to increase product reliability. In this study, we reanalyzed using the FMEA method and proposed an improved method. Domestic railways lack an accurate measurement method or system for maintenance, so maintenance decisions rely on the opinions of experienced personnel, based on their experience with past faults. However, the current selection method is flawed as it relies on human experience and memory capacity, which are limited and ineffective. Therefore, in this study, we further specify qualitative contents to systematically accumulate failure modes based on the Failure Modes Table and create a standardized form based on the Master FMEA form to newly systematize it.

• Journal of Intelligence and Information Systems
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• v.3 no.1
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• pp.111-142
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• 1997

정보 시스템 대한 유지 보수 문제는 소프트웨어 유지 보수 분야에서 지속적으로 존재하는 문제 중의 하나이며, 특히 이러한 정보 시스템들이 아주 오래 전에 COBOL이나 계측형 데이터베이스와 같은 기술을 바탕으로 개발되었음에도 불구하고 대부분의 조직에서 중요한 역할을 담당하고 있는 것이 현실이다. 따라서 이들 정보 시스템에 대한 효율적이고, 신속한 유지 보수는 조직에 있어 매우 중요한 업무임에도 불구하고, 대부분의 조직에서 이를 제대로 수행하고 있지 못하다. 체계적이고 효과적인 정보 시스템에 대한 유지 보수업무 수행을 위해 본 연구에서는 과거 유지 보수 사례를 이용하여 사례 지식을 축적할 수 있는 유지보수 사례의표현 방법 및 유사성 평가 방법과 이를 바탕으로 새로운 유지보수 요구에 적합한 과거 사례와 유지보수 대상 코드를 제안해 주는 사례 기반 유지 보수 대상 인식 방법론을 제시하였다. 이들 제안된 방법들의 타당성과 성과는 한국전력의 실제 정보 시스템을 대상으로 검증되었으며, 현장 업무에 적용되고 있다.

• Annual Conference of KIPS
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• 2011.04a
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• pp.547-550
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• 2011

The purpose of this paper is to verify and validate the maintenance tasks of the construction of a nuclear facility using a digital mock-up and simulation technology instead of a physical mock-up. Prior to the construction of a nuclear facility, a remote simulator that provides the opportunity to produce a complete digital mock-up of the PRIDE (Pyroprocess Integrated Inactive DEmonstration Facility) region and its remote handling equipment, including operations and maintenance procedures has been developed. In this paper, the system architecture and graphic user interface of a remote simulator that coincides with the extraordinary nature of a nuclear fuel cycle facility is introduced. In order to analyze the remote accessibility of a remote manipulator, virtual prototyping that was performed it by using haptic device of external input devices under a 3D full-scale digital mock-up is explained.

• Journal of the Daesoon Academy of Sciences
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• v.19
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• pp.21-45
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• 2005

The purpose of this study is to examine the establishment and development of Daesoon Thought Thesaurus. Specifically, this study examined the matters to be considered in the stage of Thesauri planning according to the Thesauri Construction process : presents the methods and standards of Thesauri Construction according to processes such as identification of the indexing policy, establishment of Thesauri system, collection of vocabulary, selection of preferred term, clustering of the terms, establishment of term relationships, overall adjustment, Thesauri test, proofreading by professional display, maintenance and updating. Since religion information is unique or totally different from the information in other areas, it is most important to construct the Thesauri suitable for system after carefully recognizing the concept of religion terms.

• Journal of Information Technology Services
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• v.8 no.1
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• pp.143-163
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• 2009

The study investigates the challenge of knowledge maintenance in the KMSs. Knowledge pieces are the embodiment of structures in an organization and need to be modified tuned to environmental change over time. Since the change of knowledge in the KMS is not made automatically, it requires user's active participation which is called maintenance action. This study shows that users are not voluntary in taking maintenance action with empirical data based upon knowledge pieces that are already established in the KMS. This article shows that the intention of maintaining KMS is negatively influenced by KM-related culture, organizational culture and the authority of knowledge piece rather than the organizational demography. An organizational culture has an influence directly upon the intention of maintaining knowledge but influence upon KM-related culture or the authority of knowledge piece, the influence indirectly related to the intention of maintaining knowledge. It can be argued that the organizational demography have only meager influence upon the intention of maintaining knowledge only by KM-related culture. This research has the implication that what factors are to be considered in maintaining knowledge pieces over time for the organization managers.

• Journal of Information Technology Applications and Management
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• v.10 no.1
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• pp.61-70
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• 2003

Many enterprises have implemented packaged enterprise resource planning (ERP) solutions rather than system development on the promises of feasible strategic benefits. Typical feasible benefits include adoption of global standards and processes through a proven integrated system, continuous version upgrading by vendors, and thus the easiness of system maintenance. The objectives of this research are to identify what makes a post-implementation success of ERP system and to figure out the critical issues and factors for the successful upgrade of packaged ERP systems. This case study was conducted based on five different organizations that have experienced system upgrade implementation. Success factors of ERP system upgrade include (1) clear statement of upgrade goals, (2) good coordination and communication among the implementation partners, (3) thorough management of customization and maintenance history including documentation, (4) Planning of system requirements of higher version, and (5) redefinition of role between business departments and IT department.

• Journal of the Korean Society for Library and Information Science
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• v.46 no.3
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• pp.297-317
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• 2012

The purpose of this study is to identify the problems of the distribution and maintenance of the KOLAS, and provide the developmental direction of the KOLAS. The research methods for this study are both survey and field interview. The results show that first, the National Library of Korea should continue to distribute the KOLAS to public libraries, and second, there are a lot of problems for maintenance of the KOLAS. However, some of the problems of KOLAS could be resolved, but not all of them. Thus, this study proposes the developmental plan of the KOLAS for future. The National Library of Korea should open the KOLAS to open source software for public, so that libraries and vendors may develop new ILS based upon the KOLAS.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3183-3191
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• 2014

It is essential to effectively manage facilities because operating and maintenance cost for them accounts for more than 83% of lifecycle cost. This study developed BIM Object-based classification list to manage information required to operating and maintenance phase of them from design and construction phase. In order to develop this classification list, Construction Information Classification System, Design Criteria for Architectural Electrical Installations, commodity list classification of PPS(Public Procurement Service) were analyzed. and problems for consisting of object classification list were drawn. And each materials is classified that drawings discipline code (KSF 1540:2010 (Principle and criteria for CAD Drawing) was classified as level 1 to cover main areas and construction information classification system was classified as level 2 to cover elements also UNSPSC was classified as level 3 to cover objects for devices and equipments. this classification criteria was given code. This study is expected to be useful to exchange and share information in operating and maintenance phase by offering object point of view classification in design and construction phase. besides, it is looking forward to effective operating and maintenance of facilities by enabling management of devices and equipments by function, space, use.