• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.127-132
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• 2006

Recently, several displacement measuring instruments such a GPS are substantially developed by development of an artificial satellite. Considering this trend, in future displacement measurement will be a very efficiency method, therefore we need to develop structure maintenance & management by using displacement measuring instruments. In this study, I suggest to maintenance & management method about simple beams and cantilever beams which are very important structurein civil engineering by using displacements. I suggest a system which trace behavior of beams by combining some measurement points and a specific displacement function and research that tl1e proper number of measurement and optimum measurement points to efficiently use the system.

• 대한치과의사협회지
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• 제54권12호
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• pp.996-1023
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• 2016

There are many kinds of maintenance care services for removable denture patient. Adjustment of the denture base and occlusion should be performed regularly not only for pain relief but also for maintaining the denture function. Direct and indirect relining are needed frequently in specific cases including mandibular distal extension case or non-symmetric residual teeth situation. Surface treatments for metal and resin are essential in the relining procedure. Clinical process for the denture repair is similar to indirect relining which needs inter-occlusal registration. Especially, the peridontal maintenance care and caries prevention are most important way to preserve the abutment teeth in partial edentulism. Moreover, the caring method for the denture and the tissue should be instructed to the denture patient.

• 대한전기학회논문지:전력기술부문A
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• 제55권9호
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• pp.392-398
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• 2006

Maintenance scheduling of generating units (MSU) has strategic dimension in an oligopolistic market. Strategic MSU of gencos can affect a market power through capacity withdrawal which is related to bidding strategy in an generation wholesale market. This paper presents a combined framework that models the interrelation between competitive bidding and strategic MSU. The combined game model is represented as some sub-optimization problems of a market operator (MO) and gencos, that should be solved through bi-level optimization scheme. The gradient method with dual variables is also adopted to calculate a Nash Equilibrium (NE) by an iterative update technique in this paper. Illustrative numerical example shows that NE of a supply function equilibrium is obtained properly by using proposed solution technique. The MSU made by MO is compared with that by each genco and that under perfect competition market.

• Journal of Astronomy and Space Sciences
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• 제14권2호
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• pp.355-366
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• 1997

This paper presents a comprehensive analytical approach for determining key maneuver parameters associated with the acquisition and maintenance of the ground track for a low-earth orbit. A livearized model relating changes in the drift rate of the ground track directly to changes in the orbital semi-major axis is also developed. The effect of terrestrial atmospheric drag on the semi-major axis is also explored, being quantified through an analytical expression for the decay rate as a function of density. The non-singular Lagrange planetary equations, further simplified for nearly circular orbits, provide the desired relationships between the corrective in-plane impulsive velocity increments and the corresponding effects on the orbit elements. The resulting solution strategy offers excellent insight into the dynamics affecting the timing, magnitude, and frequency of these maneuvers. Simulations are executed for the ground track acquisition and maintenance maneuver as a pre-flight planning and analysis.

• 산업경영시스템학회지
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• 제18권34호
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• pp.173-183
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• 1995

Life cycle cost has been one of the key criteria in design or purchasing of systems, particularly in the flying weapon system. Unexpected cost increase or system breakdown during the system life can be reduced by controlling maintenance cost A system should be designed for maintainability in early stage of product life cycle. The design should be insensitive to its environmental, organizational, and human factors in the stage of customer's utilization. This paper presents LCC as a controllable variable and also suggests a new control model for LCC analysis. The estimation of maintenance cost based upon maintenance scenario, design of maintainability followed by minimizing maintainability loss function in the beginning stage of design, and increase of useful life of systems are among the factors to control LCC.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.84-90
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• 2009

The gravel ballast in the ballasted track has the function to not only transfer/scatter the train loads to subgrade through rail and sleeper but also elastically support the train loads. Because track irregularities results inevitably from the repetitive train loads, the track maintenance should be undertaken for correcting them. By analyzing the track maintenance history in the Gyeongbu high speed railway, this study tries to choose the local two spots in the railway in which the repair frequencies are maximum and relative small; to analyze their dynamic characteristics as well as grade; and to compare them with maintenance history. As the dynamic characteristics of track, the vertical displacement and vibrating acceleration of sleeper as well as acceleration of ballast are measured/analyzed. Furthermore, by collecting soil and gravel on the reinforced roadbed and undertaking ballast screening test, the size distributions are compared with grade distribution standards of high speed railway.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 B
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• pp.562-564
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• 1995

This paper proposes a new algorithm for maintenance scheduling with considering load forecast uncertainty. The proposed algorithm is based on the equivalent load of effective load carrying capability(ELCC) of generators. The uncertainty of forecasted load is considered as a normal distribution probability density function. For maintenance scheduling, reserve levelization method and risk levelization method are used in this study. To test the algorithm, we applied the proposed method to IEEE reliability test system(IEEE RTS). As a result, we verified the validity of the proposed method.

• 조명전기설비학회논문지
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• 제28권7호
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• pp.34-40
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• 2014

In this paper, we want to know the optimal replacement cycle(time) for this study was performed. The optimal preventive replacement age can be fond by finding the value of time that minimizes the cost function(model of Barlow and Jardine). In addition, The reliability of the relay according to the service environment were studied. The use of the exchange relay period is longer, and maintenance cost rate(per hour) may increase, and also the reliability may cause a decline. In addition, considering the preventive maintenance and purchase order, a representative relay(RAX-L440-A type) life was calculated.

• 한국구조물진단유지관리공학회 논문집
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• 제3권2호
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• pp.221-232
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• 1999

This study investigates the applicability and design scheme of fieldbus network in the measurement system used for precise and safe construction as well as efficient maintenance of bridges. In order to maximize the function and performance of bridge monitoring system, this study introduces the CAN(Controller Area Network), one of the fieldbus protocols, in the measurement system of bridges. This study presents the implementation method of CAN on the monitoring system of bridge, and also proposes a bandwidth allocation scheme for the design of network. The validity of the proposed CAN design method is verified through a simulation experiment. It is shown that the CAN can be readily applicable to the measurement system of bridges.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.337-346
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• 2008

In this paper, a study an standardization of control cable numbering for high speed railway substation. Standard numbering structure of substation control cable and consistency of the number system are important for the railway substation construction and maintenance. However, currently control cable number system of railway substation was not standardization which was different according to a bander and a construct company. Therefor there is many difficult which does a same function to differ in maintenance and repair to accident. Therefor Standardizes the number system of the substation control cable is useful for an improve of construction and maintenance.