• Journal of Advanced Marine Engineering and Technology
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• v.38 no.4
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• pp.456-462
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• 2014

In this paper, we develop a facility management system which provides fault effect and replacement alarm function of each component for supporting effective maintenance of facility. To do this, we use weighting method to each component, calculate importance of each component, and make them to hierarchy structure using bill of materials of facility. Also, we draw fault cause and fault effect of components based on failure modes effects and criticality analysis, and define criteria of severity, occurrence and detection to get risk priority number. To apply these concepts, we develop and test the facility management system to verify its practicality. In the future, we expect the developed system to apply many domains such as maintenance of ship and offshore plant.

• Environmental and Resource Economics Review
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• v.31 no.4
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• pp.571-595
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• 2022

This study theoretically analyzes the cost allocation of replacement costs that occur when existing operators have to replace circuit breakers due to the entry of new generators. We adopt the sequential equal contributions rule as the cost allocation rule, which is widely used in cost allocation problems in cooperative game theory. We derive various cost allocation plans based on several criteria and examine to what extent each alternative meets various desirable axioms. According to the analysis, (i) the alternative that excludes the cost of the new operator, residual value, and network operator and (ii) the alternative that excludes the cost of the new operator, residual value, and includes network operator are relatively superior to other schemes. We also identify a realistic plan by taking into account practical factors and analyze its axiomatic characteristics.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.41 no.6
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• pp.61-66
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• 2004

To make a guide line of property control of angiography equipments, we made standard evaluation sheet forms of facility and management of angiography suite, physical properties of angiography equipments, and image quality of film and then surveyed them at 29 hospital nationwide. Survey and development of standard evaluation sheet form of physical properties of angiography equipments. By using resolution & radiation dose, physical properties of angiography equipments of 49 in number nationwide were evaluated. Most of them (91%) had good performance.

• Journal of the Korean Institute of Gas
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• v.20 no.4
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• pp.33-43
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• 2016

Grinding, weld deposition, type A sleeve, type B sleeve, composite sleeve, hot tapping and clamp are used as the method to repair the buried pipelines in the United States, UK and Europe. In the event of defect to the pipeline, they have repaired the pipeline through the fitness-for-service assessments. In addition, they have guidelines for the possible repair methods to apply to each type of damage, which is occurred due to the 3rd party construction or corrosion. According to the KGS FS551, Safety Validation in Detail including ECDA(External Corrosion Direct Assessment) as one method of integrity management should be carried out for the old pipeline which supply natural gas as the middle pressure in Korea. Where a defect on the pipelines is found, on the result of Safety Validation in Detail, the pipelines should be repaired or replaced by new piping. However, there are no guidelines or regulations regarding the repair and reinforcement of pipeline, so that, cutting the damaged pipeline and replacing it as a segment of new pipe is the only way in Korea until now. We have suggested pipeline repair methods including type A, B sleeve, composite sleeve, after the survey of foreign repair method and standards including the method of United States and the United Kingdom, and after analysis of the results on pipeline repair test including type A, type B sleeve and composite sleeve.

• The KIPS Transactions:PartC
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• v.17C no.5
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• pp.407-414
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• 2010

A condition access system (CAS) refers to a hardware-based system that allows only authenticated users to have access to contents. The CAS has many disadvantages found in that in the replacement of multiple service operator (MSO) a set-top box should be also changed and the smart-card often causes malfunction. To deal with the problems, exchangeable CAS (XCAS) was developed in 2009. However the standards or evaluation schemes for XCAS are absent. Existing evaluation schemes are not appropriate for evaluating XCAS due to the evaluation standard, the evaluation cost and efficiencies. Therefore, a specific scheme that can evaluate the security and suitability of exchangeable conditional access systems has been requested. In this paper, we propose an appropriate evaluation scheme for XCAS. The evaluation scheme includes an evaluation purpose and four components to evaluate the evaluation target, the evaluation process, the evaluation subject, and the evaluation cost involved.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.7
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• pp.765-767
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• 2016

Building Energy commissioning is a process in which verifying and making the document during entire lifetime including planning, design, construction, test run of equipment, and maintenance to minimize the operational problems of building energy efficiency. The general commissioning is replacing the equipment or reconstructing the skin to achieve the performance for the design. This process is expensive and has the disadvantage of taking a long payback period by one operation. In this paper, we studied the monitoring-based commissioning (MBCx) to increase the energy efficiency of buildings through analyzing energy use data. MBCx is modeling a building energy, comparing the real energy use with it, detecting the cause of falling the efficiency, and running the optimal operation regularly.

• Journal of the Earthquake Engineering Society of Korea
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• v.9 no.1 s.41
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• pp.43-50
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• 2005

Many highway bridges in Korea need seismic retrofit because only one decade has passed since the seismic design criteria was introduced. For the highway bridges of which bearings are worn and dysfunctional, the validity of seismic retrofit method using laminated rubber bearings was discussed in this study. Real scale RC pier specimens without seismic details were constructed. And then, Pot bearing, Rubber bearing (RB), Lead-rubber bearing (LRB) were applied to these specimens. Through pseudo dynamic test method, dynamic behavior of these RC piers under earthquake was simulated and compared. From the test results, proposed seismic retrofit method was found to be valid.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1058-1070
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• 2007

Internal and external railway management corporations are using the periodic replacement criteria of rail by accumulated passing tonnage and wear to maintain rails for servicing. However, internal the periodic replacement criteria of continuous welded rail(CWR) by accumulated passing tonnage is the one(50kg/m-5 million gross tonnage, 60kg/m-6 million gross tonnage) presented in Japan before. It was estimated with the fatigue life about 50kg N rail joints applied diesel train load but it wasn't applied to current conditions of track; elimination of rail joint, using the concrete slab track and operation of light train load and effect of welding, manufacturing technique, grinding of rail. Therefore, in this study, it was investigated the types of damage and cause in welded rails and examined standards and information resources. Also, this study presents preliminary data to revise the periodic replacement criteria of CWR by current accumulated passing tonnage in bending test of laid welded rail and a survey of track maintenance history of Seoul metro.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.5
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• pp.509-516
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• 2014

This study describes a reasonable planning method for water meter replacement which can minimize the metering under-registration for an increasement of revenue water. The increment analysis of real water usage was used to establish a replacement plan. The meter replacement database collected from K City was used as the basis of this analysis. The database included 964 connections of domestic and non-domestic consumers that had their meter replaced by aging at 2011. The result showed that the corelation between unregistered water volume and water meter age was lower than commonly expected where the current criteria of replacement is only water meter age(8 years) excluding the meters older than 13 years. And in the analysis result of water usage for 8 years, the total amount and increment of water usage had a significant effect on unregistered water volume. However the relation was different tendency as a total volume and slope of increment. In case of total water volume was larger than 10,000, larger than 7,000 and increment of 0.0 ~ -0.3, larger than 6,000 and increment more than -0.3 were analysed to need a replacement because of metering under-registration.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.5
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• pp.258-263
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• 2004

The purpose of this experiment is to modify diagnosis criterion of isothermal relaxation current(IRC) measurement equipment which is using for distribution cable diagnosis. We're using this system for several years in the field instead of DC leakage current measurement and lots of cables were replaced. But we have to investigate on the reliability of this equipment for our cables because we didn't carried out condition assessment of extracted cables after field diagnosis by this equipment. It is important thing for cable maintenance. If the replacement criterion is improper we can not prevent failures or will waste budget on account of replacement of the sound cables. In this paper we selected field installed cables and injected silicone fluid to the cables for insulation rehabilitation. In order to prove reliability of the diagnosis equipment we compared diagnosis results and AC breakdown strength according to operating time after silicone treatment. This is the results of the field test for 1 year.