• 한국소음진동공학회논문집
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• 제13권9호
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• pp.671-678
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• 2003

Spacer dampers maintain the constant gaps between each conductor in a bundle conductor-transmission line, and are installed at proper intervals to keep a line from all sorts of damages derived from the vibration energy caused by mechanical or electrical external factors. It is most important to embody a technology which considers difficulties of maintenance and repair, and has optimum elements in order to prevent accidents such as destruction by fire or the snapping of a wire by the effect of vibration phenomenon coming from transmission line. In the present thesis, therefore, the analysis of vibratory characteristics of spacer damper is set up by analytical methods such as the analysis of conductor motion's governing equation, the equation of spacer damper's motion, spacer damper-fastened wire's motion in a span, and the numerical analysis of finite difference method. Furthermore, the installation distance between spacer dampers was scrutinized by simulations of various vibration phenomena which change at any time as actual conditions do, and hereafter we will be able to analyze all kinds of vibration phenomena coming from a boltless spacer damper with 6 bundle conductor for 765 k V transmission line based on new analytical methods.

• 한국산학기술학회논문지
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• 제10권11호
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• pp.3115-3120
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• 2009

전기선로전환기는 열차가 진행하고자 하는 진로로 운행할 수 있도록 분기기를 전환시키는 설비로서 도시철도 및 간선철도를 비롯한 대부분의 철도에서 많이 설치되어 사용되고 있다. 이러한 전기선로전환기의 유지보수 작업대부분은 유지보수자들이 포터블 계측기를 이용하여 수작업으로 현장에서 모터 전원, 제어 전원, 표시 전원에 대한 측정을 하는 것이다. 특히 NS형 또는 NS-AM형 전기선로전환기의 경우에는 유지보수 주기가 너무 잦기 때문에 이러한 측정에 많은 인력이 요구되고 있을 뿐만 아니라 작업 도중 부주의에 의한 사상사고도 발생하고 있다. 본 논문에서는 이러한 유지보수 작업의 향상을 위해 현장에 설치된 전기선로전환기의 상태를 모니터링하는 시스템을 제안하고 있으며, 이러한 모니터링 시스템은 전기선로전환기에 대한 각종 측정값을 실시간으로 확인하여 유지보수 업무의 향상을 이룰 수 있을 것으로 기대된다.

• 산업경영시스템학회지
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• 제42권3호
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• pp.89-94
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• 2019

K1A1 tank commander's primary thermal sight is a device that enables tank commanders to detect, identify, aim and track the target by observing targets in all directions during day, night and in situations of smokescreen and fog through $360^{\circ}$ rotation independent from the gunner's primary thermal sight and stabilizing the line of sight even under the vibrations occurring when the tank is standstill and moving. The main function of this device is to detect and process visible and thermal images and deliver the final images to the tank commander. One of the core parts to that end is the observation window (daytime/thermal image window). This core part is mounted at the entrance of the optical path for observing the target and plays the role of making visible light during the daytime and infrared light during the night pass through the target and transmitting the resultant images to the internal optical system of the tank commander's primary thermal sight. Such core parts have been selected as depot maintenance items so that they are replaced by new parts instead of being recycled when they are subjected to maintenance in most cases. That is, the military budget is wasted because such parts are replaced by new parts despite that they can be recycled for maintenance. Therefore, this study proposed a mounting tool for polishing and coating observation windows (daytime and thermal image window) using planar polishing equipment and DLC (Diamond-Like Carbon) coating equipment. In addition, this study presented an amendment (proposal) of the Depot Maintenance Work Request (DMWR) already published to verify the performance of recycled products including the establishment of inspection standards for recycling processes.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 A
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• pp.516-518
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• 2003

Our transmissions are mostly constructed on the mountains and passing over the mountains. The height of transmission lines are generally decided from the trees on the mountains. The height of the transmission lines is very important, because it has an effect on construction and maintenance costs of the transmission lines. We carried out tests for electrical impulse characteristics between trees and transmission lines, and suggested the test results.

• 한국신뢰성학회지:신뢰성응용연구
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• 제17권1호
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• pp.58-65
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• 2017

Different from general operating policies applied for various waiting line situations, two complementary dyadic operating policies are applied alternatingly to a single server maintenance service center model. That is, either of the two dyadic Min (N, T) or Max (N, T) policy is applied to operate such center first and the other operating policy should be applied later, and then the same sequence of both operating policies is followed repeatedly. This operating policy is denoted by the Minimax (N, T) policy. Purpose: Because of the newly introduced operating policy, important system characteristics of the considered service center model such as the expected busy and idle periods, the expected number of customers in the service center and so on should be derived to provide necessary information for determination of the optimal operating policy. Methods: Based on concepts of the newly introduced Minimax (N, T) policy, all necessary system characteristics should be redefined and then derived by constructing appropriate relations between complementary two dyadic operating policies. Results: Desired system characteristics are obtained successfully using simple procedures developed by utilizing peculiar structure of the Minimax (N, T) policy. Conclusion: Applying Minimax (N, T) operating policy is equivalent to applying the simple N and T operating policies alternatingly.

• 산업경영시스템학회지
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• 제22권53호
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• pp.45-54
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• 1999

Manufacturing today is becoming increasingly competitive. If a company is to exist and successfully compete, it must pay very careful attention to production management, total quality assurance and total proactive maintenance issues. Overall machine performance, repair efficiency, system level utilization, productivity and quality of output need to be optimized as possible. To accomplish that objective, the behavior of manufacturing equipment and systems need to be monitored and measured continuously if it is possible. Then early warning of possible failure should be generated and proacted on that type of the situation to improve overall operation performance of manufacturing environment. In this paper, Proactive maintenance framework using performance-based reliability structure as enabler technology is proposed. Its paradigm enables one to maximize system through-put and product quality as well as resources in the performance domain. In the case of inadequate knowledge of the failure mechanics, this empirical modeling concept along with performance degradation knowledge can serve as an important product and process improvement tool. The real-time framework extension to proposed framework uses on-line performance information and is capable of projecting the remaining useful period.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1821-1826
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• 2008

The construction of concrete slab track system is increased recently because the system has advantages which are maintenance free and so on. However, the noise level on slab track is 3 db(A) higher than the one on ballast track since most of noise is reflected on slab track. Currently, concrete slab track systems has been designed for Gyungbu high speed line stage 2 and Honam high speed line. For those tracks, noise absorbing blocks are considered. Therefore, test methods and proper criteria for structural performance and reduction efficiency of noise absorbing blocks are required. In this study, tests were performed according to established test methods and criteria in previous study and the results have done comparative analysis.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.315-317
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• 2008

Recently, a new construction of transmission line has been through quite hard situation due to demands for a new construction of transmission line have been saturated in south korea and also difficulties of purchasing the routes. In addition, the demands for electricity have been decreased in all of advanced countries of the world due to slowdown of the rate of economic growth. So they are trying to find a way to utilize a existing transmission line by extending the durable period. Therefore this is necessary to apply an applicable technology on domestic markets such as inspection, examination, maintenance of existing transmission lines by introducing advanced countries's example which shall be based on Japan's electric power companies.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 추계학술대회 논문집
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• pp.328-335
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• 2000

The substructure of Light Rail Transit is mainly built on elevated structure that is composed of pier, girder and bridge deck. The bridge deck mostly has been made by field formed reinforced concrete so far. The objectives of the study are to find a method for design and construction of the new bridge deck. I-beam is fabricated to make grid and concrete is poured on it at factory. This type can be used for maintenance of duty line by advantages such as good quality control and short construction time.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 B
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• pp.513-515
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• 1997

The main purpose of this study was to develope the prototypes of on-line supervision system for maintenance to protect the confidence of operation of electric facilities in buildings. The influence of the harmonics on the electric facilities in building, which is recently growing more and more serious, were also analysed, and finally the essential techniques on the condition supervision, diagnosing method of facilities were proposed.