• Journal of the Korean Society for Aviation and Aeronautics
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• v.23 no.1
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• pp.1-7
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• 2015

The aircraft maintenance demands a lot of aviation mechanics in urgent according to the high season and low season in seasonal demand adjusted, unplanned maintenance work such as AD (airworthiness directives) and troubleshooting of aircraft system fault. The advent of Super-Large Aircraft such as A380 with aircraft materials, power plant and avionics systems which were not in previous models must be expected to increase the complexity of the aircraft maintenance system. This study is intended to propose the development plan for formation of positive flexibility culture in aircraft maintenance organization through the review of previous research on flexibility culture of organization and through empirical research for bureaucratic and poor factors by the evaluation of flexibility culture level of domestic aircraft maintenance organization.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.7
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• pp.8-13
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• 2015

Recently, because a renewable power source must operate as a constant rate in accordance with RPS(Renewable Portfolio Standard), the study of the renewable power sources has been ongoing. Especially because of noise of wind turbine, troubleshooting, and urban greening business, research related with small wind turbine are underway. The economics and reliability are important parts for the activation of small wind turbine, such as solar energy. In this paper, by analyzing the temperature variations for each location and efficiency of power conversion devices in accordance with short period wind speed changes in simulation test, we reviewed the safety about temperature variations of wind generator and the method of selection of power converter.

• Proceedings of the KIEE Conference
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• 2005.07d
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• pp.2597-2599
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• 2005

This research is developing the technique of troubleshooting in digital excitation system of nuclear power plant. and the design technique of excitation system is thought to be advanced through this research. Especially, the development of simulator enables to accumulate digital control technique, more analysis for excitation system algorithm. etc helps to develop other nuclear power plants.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.4
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• pp.502-508
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• 2009

To obtain high power, diesel engines continuously increase combustion pressure and mean effective pressure each cylinder, and the excitation sources and noisy sources are increased, too. Moreover, to reduce the costs, shipyards make hull structures weaker than before. As above reasons, it is more difficult to control the vibration phenomenon nowadays. In this study, it was investigated why diesel generator sets reached the vibration allowable limits during the FAT and heavy vibration phenomenon of diesel generator sets using ODS test during onboard tests. Also, it is found out the stiffness of deck and common bed using the test result of their structural impedance. To find out the vibratory characteristics of diesel generator sets, model tests were carried out. From the sensitivity analysis after above tests, it was selected points to be reinforced and studied troubleshooting to solve heavy vibration phenomenon of diesel generator sets.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.510-513
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• 2001

Several kinds of vibration problems have been frequently encountered in industrial vertical pumps in spite of their widespread use for long time. In fact, vibration problems of the vertical pumps are so complicated and difficult with compared to those of the horizontally mounted pumps that more careful attention should be taken for solving the vibration problems. This paper introduces a case study experienced from troubleshooting for excessive vibration occurred in a vertical-type condensate pump for combined cycle power plants. Subsynchronous whirl vibration was caused by the instability of the guide bearing whose lubricant is water. A newly modified guide bearing has solved the vibration problem, which should be the best countermeasure.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.249-254
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• 2007

A PSD which cooperates with train door provides safety and convenience for passengers. In order to cooperate with train door, the PSD should interface between the PSD control system and the control units of train door. This interface is generally performed in signaling system(ATC/ATO), however, the lines which don't have the interface functionality in the signaling system, it is required to have additional "PSD inter face system" to communicate between train and PSD. In this paper, we propose a safe PSD interface methodology by discussing interlocked control between train door and PSD, recognition of accuracy stop point, troubleshooting logic and log of troubles and driver panel which are adopted in Inchon line1.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.03b
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• pp.213-217
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• 1999

An expert system is developed for rational and efficient design of multi-component injection molding which is a fairly new manufacturing technique to produce plastic parts by injecting two or more materials sequentially using multiple injection units in a single machine into a single rotary mold. The knowledge base used in the present design system is primarily composed of two parts ; knowledge from domain expert and knowledge from CAE analysis. The present expert system has hour main modules ; general design guidelines for injection molding specific guidelines for multi-component injection molding redesign guidelines from the result of the CAE analysis and finally troubleshooting for multi-component injection molding. To show the validity of the present design methodology two shop floor design problems were tested ; design and fabrication of timing belt cover and power window's assist knob by using multi-component injection molding.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.11a
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• pp.179-183
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• 1999

Rubbing occurs when a rotating element comes in contact with a stationary element. In the steam turbines, the rotating element is the rotor while the stationary elements are usually the oil deflectors and packing seals. Rubbing phenomenon may be often obseued on a new or rebuilt machine rather than on a machine that has been operating for several months or years. Rubbing in the turbine has been classified into two modes by the operating conditions: 1) start up or shut down, 2) steady state. At start up or shut down operation, rubbing produces synchronous whirl vibration, which are caused by thermal bow of the shaft due to localized heating on the shaft surface. While subsynchronous whirl vibration is caused by partial rubbing during the steady state operation. In this paper, the two case studies of troubleshooting for excessive vibration caused by rubbing in the actual steam turbines are investigated.

• Journal of The Korean Digital Architecture Interior Association
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• v.12 no.4
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• pp.125-132
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• 2012

In this study based on BIM(Building Information Modeling) apply for performing efficient remodeling project and utilized. And this study will examine a real project where a BIM based process was used in the remodeling of an single-family homes. In the remodeling design phase of the planning process was conducted for the BIM process modeling, BIM in the remodeling stage while performing the required range and level of the remodeling process were studied. Based on this, communication between client and remodeling designer, participants more expect that smooth and speeds up in remodeling. For client decision support, troubleshooting of remodeling of the design process to be effective in the BIM have been identified. The BIM model and deliverables data used for the remodeling design process of building remodeling is the most effective way, due to the increased efficiency gained in many areas.

• Journal of the Korea Society of Computer and Information
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• v.20 no.12
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• pp.181-188
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• 2015

In this paper, we propose a Science subject program based on programming learning to improve computational thinking ability in middle school. As the necessity of software education rises recently, the subject of information was designated as the mandatory subject in elementary, middle and high schools. In order to cultivate the ability that enables the leaners to search the knowledge in need by themselves and raise troubleshooting method, not the existing indoctrination, his thesis was willing to improve Computational Thinking ability and improve the ability of considering and thinking the matters by using scratch language. For that, this thesis developed and suggested science subject program that utilizes the programming learning.