• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.203-206
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• 2000

In the multi-purpose lathe, the design of tilting turret slide system has an important and critical role to enhance the accuracy of the machining process. Tilting turret unit is traveled by 3-axis slide systems. There is a need to design this part very carefully. In this research, the 3-axis slide system with tilting turret unit is researched with two approaches; The first is that 3-axis slide system is modeled and simulated usig ADAMS software. The dynamic behavior of this system is visualized by data graphs and dynamic animations. The first step of virtual prototype which makes it possible to design economically and effectively is developed.

• Journal of the Korean Society for Railway
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• v.9 no.5 s.36
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• pp.577-581
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• 2006

Urban transit operation corporations perform repetitive work to investigate the EMU, electric multiple unit, by some fixed maintenance cycle. The quality of maintenance work usually depends on workers' know-how. Though some information to support the maintenance work is digitalized and provided to workers, it is not great help to them because of its non systematic structure. The information includes drawings, manuals, work results, work history, fault history, etc. The maintenance workers want to access the information anytime anywhere, and make an effect to promote the efficiency of maintenance for EMU. But it is difficult to achieve that without some structured information system which is able to use in work area. So we develop maintenance information system for EMU for about 4 years from 2002 to 2005. In this paper we present the configuration and characteristics of this system, and the results of the evaluation test. We install the system in two depots, Changdong and Jichuk, belonged to SeoulMetro to evaluate its efficiency and estimate its economic benefits.

• Journal of Power System Engineering
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• v.19 no.3
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• pp.75-80
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• 2015

Typically, robot system configured by articulated robot manipulator with 1 DOF transfer unit is being applied in automotive manufacturing automation process. Especially, 1 DOF transfer unit is necessary to extend workspace of robot manipulator. In this configuration, because transfer unit works only one direction, robot manipulator only works in one side in case of car body painting or sealing automation process. it is necessary three robot manipulator system at least. In this paper, in order to robot manipulator works effectively in car body sealing automation application, we are suggested omni-directional manipulator system and conducted studying on redundancy resolution method to solve manipulability-optimal problem.

• Korean System Dynamics Review
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• v.1 no.1
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• pp.103-131
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• 2000

If a system such as a port has a large boundary and complexity, and the system's substance is considered as a black box, forecast accuracy will be very low. Futhermore various components in a port exert significant influence on each other. To copy with these problem the form of structure models were introduced by using SD method. The Competitive Ports Model had several sub-systems consisting of each Unit Port models, and each Unit Port model was made by quantitative, qualitative factors and their feedback loops. The fact that all components of one port have influence on the components of the other ports should be taken into account to construct Competitive Port Models. However, with the current approach that is impossible, and in this paper therefore, models were simplified by HFP adapted to integrate level variables of unit port models. Although many studies on modelling of port competitive situation have been conducted, both theoretical frame and methodology are still very weak. In this study, a new algorithm called ESD(Extensional System Dynamics) for the evaluation of port competition was presented, and applied to simulate port systems in northeast asia.

• Proceedings of the KIEE Conference
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• 2001.07a
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• pp.16-18
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• 2001

Recently, a study on operation in parallel between Distributed Generation(DG) unit and power distribution system has been growing interest in power distribution system. But, introducing the DG unit causes the problem due to rising the voltage variation on power distribution system. So, This paper presents the effect of introducing DG unit on distribution system. For this simulation, KEPCO distribution system is used.

• Current Optics and Photonics
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• v.4 no.3
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• pp.186-192
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• 2020

This paper describes a real-time monitoring system in Ethernet passive optical networks (EPON) that uses burst-mode fiber Bragg grating (FBG) optical sensors. The FBG interrogation unit in the optical line terminal (OLT) transmits the monitoring wavelength to optical network units (ONUs). The FBG sensor unit in each ONU returns a burst-mode monitoring signal to the OLT. As the system applies time division multiple access (TDMA), a uniform Bragg wavelength can be used to monitor the EPON system. The FBG interrogation unit analyzes the received burst-mode monitoring signals and outputs fault information on the ONU branches in EPON. The simulation results show the effectiveness of the proposed monitoring system based on TDMA. In addition, we compared the proposed TDMA-based monitoring system with a WDMA-based monitoring system.

• The Mathematical Education
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• v.43 no.3
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• pp.309-314
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• 2004

A standardized scoring system for college interview entrance examination means we standardize the score of examination to adjust the degree of difficulty among questions and difference of panel's disposition. A standardized scoring system were newly enforced at college interview entrance examination from 2001. Colleges want to choose the most suitably qualified students, taking full advantage of interview examination. Also they should always prepare for questions, plan the answers and a standardized scoring system so that all candidates get a fair shake. The main purpose of this paper is to provide a standardized scoring system for interview examination. The results of interview examination are ranked from highest to lowest and each candidate have different rank from several panels. So some unit scores from panels are given for each candidate using standard normal distribution. Then we calculate the mean unit score for each candidate and final interview entrance examination scores are given using the mean unit score for each candidate.

• Journal of IKEEE
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• v.26 no.1
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• pp.133-136
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• 2022

This paper is about motion gesture recognition system, and proposes the following improvement to the flaws of the current system: a motion gesture recognition system and such algorithm that uses the video image of the entire hand and reading its motion gesture to advance the accuracy of recognition. The motion gesture recognition system includes, an image capturing unit that captures and obtains the images of the area applicable for gesture reading, a motion extraction unit that extracts the motion area of the image, and a hand gesture recognition unit that read the motion gestures of the extracted area. The proposed application of the motion gesture algorithm achieves 20% improvement compared to that of the current system.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.349-350
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• 2022

Recently, AI (Artificial Intelligence) has been applied to various technologies such as automatic driving, robot and smart communication. Currently, AI system is developed by software-based method using tensor flow, and GPU (Graphic Processing Unit) is employed for processing unit. In this work, we developed an FPGA-based (Field Programmable Gate Array) AI system , and report on image recognition system to realize the AI system.

• Proceedings of the KIEE Conference
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• 2006.11a
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• pp.351-353
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• 2006

Preventive maintenance can avail the generating unit to reduce cost and gain more profit in a competitive supply-side power market. so, it is necessary to perform reliability analysis on the systems in which reliability is essential. In this paper, FMECA assessment adopted using real historical failure data in Korean power plants for apply RCM analytical method. The stochastic FMECA is an engineering analysis and a core activity performed by reliability engineers to review the effects of probable failure modes of generating unit and assemblies of the power system on system performance. Optimal RCM schedule which is considered the severity level of each generating unit and failure probability from failure prediction of generating unit can be planned using proposed FMECA with IOE index.