• Journal of Korean Society of Industrial and Systems Engineering
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• v.30 no.4
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• pp.111-117
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• 2007

Comparing with bar-code systems, RFID systems can supply more efficient work. Using RFID systems, logistic management systems could be helped effectively to gather real-time information. It's available to reduce the working time and object's delay time, and to deal with real-time information by using RFID system. Until now, based on how many pallets used, there is few study about best workload of RFID system. Therefore, in this study, both bar-code and RFID system simulations were executed for inspection process in distribution center. As a result, following the ware pallet quantity, the total cost of both working time and other delay times were calculated and the sensitivity analysis of total cost trend was executed.

• Journal of Institute of Convergence Technology
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• v.4 no.2
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• pp.17-21
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• 2014

This paper presents the effects of the time delay on the stability of the haptic system that includes a virtual wall and a first-order-hold method. The model of a haptic system includes a haptic device model with a mass and a damper, a virtual wall model, a first-order-hold model and a time delay model. In this paper, the time delay is considered as the computational time delay that is assumed to be as much as the sampling time. As the time delay increases, the maximal available stiffness of a virtual wall model is reduced reversely. The relation among the time delay and the maximum available stiffness, the mass and the damper of the haptic device are analyzed using the MATLAB simulation.

• Journal of Integrative Natural Science
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• v.10 no.4
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• pp.232-239
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• 2017

The researcher set up multiple sensor units on the road slope such as national highway and highway where there is a possibility of loss, and using the acceleration sensor built into the sensor unit the researcher will sense whether the inclination of the road slope occur in real time, and Based on the sensed data, the researcher tries to implement a system that detects collapse of road slope and dangerous situation. In the experiment of measuring the error between the actual measurement time and the judgment time of the monitoring system when judging the warning of the sensor and falling rock detection by using the acceleration sensor, the error between measurement time and the judgment time at the sensor warning was 0.34 seconds on average, and an error between measurement time and judgment time at falling rock detection was 0.21 seconds on average. The error is relatively small, the accuracy is high, and thus the change of the slope can be clearly judged.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.7 s.94
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• pp.1678-1685
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• 1993

This paper considers a time delay control of noncolocated flexible mechanical systems in discrete time domain. A stability criterion suggested in the previous paper is,extended in the consideration of infinite mode property of flexible systems and finite control sampling frequency. Based on the stability criterion, the one step advanced discrete time derivative control is suggested, which can stabilize infinite number of modes of a flexible system. The sensitivity analysis shows the robustness of the one step advanced control to the system parameter uncertainties and time delay errors. Application to a simply supported beam verifies the extended stability criterion and the effectiveness of the one step advanced D-control.

• Journal of the Korea Institute of Military Science and Technology
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• v.3 no.1
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• pp.13-25
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• 2000

A simulation model is developed to analyze the large-structure driving system and its integrated behavior in the whole weapon system. It models every component in the driving system such as mechanical and electrical characteristics, and it is programmed by simulation language in a way which strongly reflects the system's real time dynamics and reduces computation time as well. A useful parameter identification method is proposed, and it is tuned on the given physical system. The model is validated through comparing to real test, and it is applied to analysis and prediction of integrated system functions relating to the fire control system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.7
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• pp.1305-1313
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• 2011

Web based online real-time reliability integrated information system is asked rapidly for more efficiency and demand response in recent. As the utilization of renewable resources has been receiving considerable attention in recent years, the information system requirement is increased. Specially, the reliability information system is more important for implementing the smart grid. This paper describes architecture of the WORRIS(Web based Online Real-time Reliability Integrated Information System) Version 7.0 system that simulates the reliability indices in composite power system considering wind turbine generators(WTG) developed successfully in this paper. And we had simulated the case study using Jeju island power system data.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.11a
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• pp.125-128
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• 2005

This paper presents a simple methodolosy that makes a continuous-time nonlinear system chaotic using fuzzy control. The nonlinear system is represented by the T-S fuzzy model. Then, a fuzzy controller makes the T-S fuzzy model, which could be stable or unstable, bounded and chaotic. The verification of chaos in the closed-loop system is done by the following procedures. We establish an asymptotically approximate relationship between a continuous-time T-S fuzzy system with time-delay and a discrete-time T-S fuzzy system. Then, we verify the chaos in the closed-loop system by applying the Marotto theorem to its associated discrete-time T-S fuzzy system.

• Journal of Power System Engineering
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• v.13 no.4
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• pp.38-42
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• 2009

The Injection molding is used more than 70% of total production in plastic products. The injection molding process has 4 processes such as filling, packing, cooling and ejecting. now then, cooling process spends the most of times in Injection molding cycle time. Therefore, it is important to control the mold temperature in producing plastic products. The cooling system and time affect the product's quality and productivity. Especially, cooling time has about 60% of total injection cycle time. Therefore, we can improve a productivity by shortening cooling time. In this study, the rapid cooling system was developed and performed a efficiency test. This system could refrigerate coolant to $1^{\circ}C$ and had to need 10 minutes for normal operating.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.10
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• pp.1361-1367
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• 2013

This paper describes and suggests the data visualization for real time power system operation based on energy management system. Because real time power system operation performs analysis of the vast amount of on-line data, the operators need intuitive data visualization to find out useful information in the big data. Especially, in emergency situation, the data visualization is able to assist the operators in handling the crisis quickly and efficiently. Therefore, this paper aims to improve displays of output of real time power system operation by visualizing on-line big data. Through this study, we can develop improved visualization technique for real time power system operation, which has highly readable displays of output and intuitive information.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.333-335
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• 2006

This paper presents a force-reflecting teleoperation scheme with time delay. In reciprocal systems, to improve the stability and performance of the tleleoperation system, the network provides a wide bandwidth, no congestion. However, as use of Internet increases, congestion situation of network increased and transmission time and packet loss increased accordingly. This can make system unstable at remote control. In this paper, we present a passive control scheme for a force reflecting bilateral teleoperation system via the Internet and we investigated how a varying time delay affects the stability of a teleoperation system. A new approach based on a passive control scheme was designed for the system. The simulation results and the tracking performance of the implemented system are presented in this paper.