• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.503-508
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• 2003

Heating, Ventilation and hir Conditioning (HVAC) system in nuclear facility should be equipped and constructed more stable and allowable than that in common facility. The purpose of HVAC system is the maintenance of optimum working environment, the protection of worker against a contaminated air and the prevention of atmospheric contamination due to a outward ventilation, etc.. The basic scheme of a safety operation of nuclear facility is to prevent the atmospheric contamination even in low level. The adaptability of HVAC system should be taken into account in the design stage so that it is possible to modify the system which is in operation. In this study, the design requirements of HVAC system in nuclear facility and the HVAC systems in foreign countries are reviewed, and the results can be utilized in the design of HVAC system in nuclear facility.

• The Journal of Korean Association of Computer Education
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• v.5 no.4
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• pp.61-69
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• 2002

Software documents consist of a number of logical objects and relationships between them, and a lot of versions are generated during software development. When an object is changed, it is desirable to easily identify the change and the range of change propagation for efficient software development and maintenance. However, it is difficult to identify it in a coarse-grained object management model. To solve this problem, fine-grained object management is required. In this paper, I propose a consistency management model for fine-grained software objects based on operation history applied to edit software objects. This paper presents a formal model for consistency management at the fine-grained level. Consistency between documents is managed using dependency between objects and kinds of the operations applied to the objects so that unnecessary change propagation can be avoided.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.393-396
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• 2007

Recently one level higher intelligent switching board than established one by the application of intelligent building and digital system are being constructed. Therefore facility's high efficiency, high degree satisfaction, miniaturaization, standardization through application of communication technology and monitoring and controlling by computer system utilized by web-basis power control system and electric IT are practiced. Especially network must be constructed through unified IBS server that monitors every educational institute's switching boards in real time control system. And I intend to create methods to save energy and raise electricity quality by power demand prediction and remote-controled management and operation. In this thesis I intend to suggest measures of forming unified system through researching educational institute's ways of constructing switching board and status analysis and overcoming technical difficulties in user's side and saving and maintenance expense.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1205-1210
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• 2004

The 4-20mA analog signal used in the various industrial fields to interface sensor in distributed process control has been replaced with relatively simple digital networks, called "fieldbus, and recently by Ethernet. Significant advances in Internet and computer technology have made it possible to develop an Internet based control, monitoring, and operation scheduling system for heating, ventilation and air-conditioning (HVAC) systems. The seamless integration of data networks with control networks allows access to any control point from anywhere. Field compatible field devices become so-called "smart" devices, capable of executing simple control, diagnostic and maintenance functions and providing bidirectional serial communication to higher level controller. The most important HVAC of BAS has received nationwide attention because of higher portion of more than 40% in building sector energy use and limited resources. This paper presents the Internet-based monitoring and control architecture and development of LonWorks control modules for AHU (air handling units) of HVAC in viewpoint of configuring BAS network. This article addresses issues in architecture section, electronics, embedded processors and software, and internet technologies.

• Journal of Navigation and Port Research
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• v.46 no.6
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• pp.562-569
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• 2022

The alarm monitoring technology applied to existing operating ships manages data items such as temperature and pressure with AMS (Alarm Monitoring System) and provides an alarm to the crew should these sensing data exceed the normal level range. In addition, the maintenance of existing ships follows the Planned Maintenance System (PMS). whereby the sensing data measured from the equipment is monitored and if it surpasses the set range, maintenance is performed through an alarm, or the corresponding part is replaced in advance after being used for a certain period of time regardless of whether the target device has a malfunction or not. To secure the reliability and operational safety of ship engine operation, it is necessary to enable advanced diagnosis and prediction based on real-time condition monitoring data. To do so, comprehensive measurement of actual ship data, creation of a database, and implementation of a condition diagnosis monitoring system for condition-based predictive maintenance of auxiliary equipment and piping must take place. Furthermore, the system should enable management of auxiliary equipment and piping status information based on a responsive web, and be optimized for screen and resolution so that it can be accessed and used by various mobile devices such as smartphones as well as for viewing on a PC on board. This update cost is low, and the management method is easy. In this paper, we propose CBM (Condition Based Management) technology, for autonomous ships. This core technology is used to identify abnormal phenomena through state diagnosis and monitoring of pumps and purifiers among ship auxiliary equipment, and seawater and steam pipes among pipes. It is intended to provide performance diagnosis and failure prediction of ship auxiliary equipment and piping for convergence analysis, and to support preventive maintenance decision-making.

• Current Optics and Photonics
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• v.7 no.1
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• pp.33-37
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• 2023

Real-time adaptive control of laser output polarization is presented in a 10-W-level non-polarization-maintaining (non-PM) fiber amplifier. While the output polarization from a non-PM fiber amplifier tends to be irregular, depending on output power, time, and perturbation, closed-loop polarization control can maintain the polarization extinction ratio at higher than 20 dB. Real-time polarization control can attain the target linear polarization mostly within 1.4-25 ms and shows stability against external perturbations. This approach can satisfy both linear polarization and high output power in a non-PM amplifier, and facilitates optimization of laser performance and maintenance-free operation.

• Knowledge Management Research
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• v.3 no.1
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• pp.41-60
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• 2002

This paper defines measurement index items and weight of the index for the purpose of developing a performance measurement index that balancedly measures performance of B2B electronic commerce. The deductive research is used for the development of measurement index items and Analytic Hierarchy Process(AHP) method for the development of weight of the index. This paper has four performance measurement perspectives-finance, partners, business process and human resources, which based the existing researches of balanced performance measurement. This researchers developed eleven second level criteria and twenty-six indexes under four perspectives through the deductive method and expert interviews, weighted on the perspectives, criteria and indexes in accordance with the forms of e-marketplace-vertical and horizontal. As a result, the most important indexes are the maintenance of partners and the efficiency of operation process in the vertical e-marketplace. In the horizontal e-marketplace, the collection of partners, development and prediction processes are more important than other indexes.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.25 no.5
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• pp.60-66
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• 2002

The military services have sought to improve the overall quality, management, and delivery of military technical information in all of its aspects. The efforts concentrated on developing IETM(Interactive Electronic Technical Manual) by using the application of computer technology for the storage, control, and presentation of maintenance, system-operation, training, and other forms of logistic-support technical information. In this paper, the methodologies are presented to evaluate the operational effectiveness of IETM which consists of confirmity and performance. Confirmity is evaluated by the check-sheet based on the standard of CALS, and performance by the comparison of the technician performance between IETM and paper-TM.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1629-1635
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• 2011

Because LRT project is large infrastructure projects investing enormous budget and required continuous maintenance after construction, it is the global trend to perform business in terms of life-cycle from the initial construction, operation to disposal. It is very important LRT to manage interfaces efficiently and to integrate vehicle, civil, track, electricity, communications, signals, operations, facilities organically. Global companies of the railway developed countries including Europe are getting orders a large rail project and preempting the world market based on engineering technology. But, domestic LRT systems engineering is the subcontracting level to the lack of practical skills and experience. Thus, technology securement is very urgent for the independence of systems engineering technology and overseas advance based turnkey. In this paper, we are going to study applicable systems engineering technology focusing on LRT system based on international standard ISO/IEC 15288.

• Journal of Korean Tunnelling and Underground Space Association
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• v.25 no.6
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• pp.569-582
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• 2023

In recent years, the service life of major SOC facilities in south korea has exceeded 30 years, and rapid aging is expected within the next 10 years. This has led to a growing recognition of the need for proactive maintenance of these facilities. Consequently, there have been numerous research efforts to introduce smart inspection technologies into maintenance. However, the current system relies primarily on manpower for safety inspections and diagnostics, and on-site surveys rely on visual inspections. Manpower inspections can be time-consuming, and subjective errors may occur during result analysis. In the case of tunnels, there are disadvantages, such as the loss of social overhead capital due to partial closures during inspections. Therefore, institutionalizing smart safety inspections is essential, considering specific measures like using advanced equipment and updating qualifications for experts. Furthermore, it is necessary to verify and validate safety inspection results using advanced equipment before instituting changes. This could be achieved through national-level official research programs and the operation of verification and validation institutions. If smart inspection technology is introduced into maintenance, routine inspections of SOC facilities, such as tunnels, will become feasible. As a result, maintenance technology capable of early detection and proactive response to safety incidents caused by changes in facility conditions is anticipated.