• Proceedings of the KWS Conference
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• 2002.10a
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• pp.433-438
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• 2002

The education, examination and qualification systems around the world are now changing rapidly and unifying as one system. The Korean national system should be harmonious with this international tendency, in order to overcome the high degree of international economic competition. In this article, the current state of the international and national systems are critically compared and discussed with the intention of proposing improvements to the Korean national system. The Korean Welding Society has revamped its system so that its certificates might be recognized by the welding institutions in foreign countries such as the European Welding Federation (EWF) and still be recognized by the Korean Government. Their desire to join the system of International Institute of Welding (IIW) was also a factor in the restructuring.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1091-1093
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• 1999

This paper discusses the surveying of a power transmission line using Real Time Kinematic(RTK) GPS technology. The use of RTK provides users with an accurate position at the moment in time. Application result of a 765kV transmission line surveying proved to be more accurate and efficient than using a traditional EDM (Electro-magnetic distance measurement) method. More, decrease in numbers of trees cut down which is a major cause of public discontents was achieved. Improvements in doing a surveying of a power transmission line using GPS is expected in the future.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.971-976
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• 1996

A flexible pointing system mounted on top of a vehicle suffers from performance degradation due to bending vibrations as the vehicle runs on a bump course. In order to improve the pointing performance, the pointing structure's vibrations should be suppressed. In this paper, a nonlinear controller is designed to control the tip position of the pointing system while actively suppressing the vibrations. To cope with high order dynamics and nonlinearities of the plant and hydraulic actuating system, a two-stage sliding mode controller is devised. The desired actuating pressure is obtained in the first stage and then the in put current In the hydraulic servo system is computed to generate the pressure. The simulation results show the effectiveness of this scheme and improvements in pointing accuracy.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.275-276
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• 2006

An intelligent arm-wrestling system is recently developed in our laboratory that is comprised of an arm-force generation mechanism and a control system that detects the maximum arm-force of a user in the early stage of the match, generates a different game scenario each time, and executes force feedback control to implement the scenario. This paper presents the mathematical model of the force control system of the intelligent arm-wrestling system, and some improvements of it via experimental frequency responses using a control signal analyzer.

• Journal of Aerospace System Engineering
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• v.8 no.2
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• pp.33-39
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• 2014

Feathering spindle is one of the critical parts of the rotor system in the Smart Unmanned Aerial Vehicle(SUAV) that it was manufactured with special material, Maraging C300. During the initial ground and tie-down flight tests of the SUAV, surface of the feathering spindle contacting to the needle-roller bearings showed excessive wear and dent due to high vibrating loads transferred from the rotating blades. Gas nitriding process was applied to the bearing contact surface of the feathering spindle to increase surface hardness so as to improve the surface defects. This paper briefly presents the gas nitriding process adopted and the spindle quality improvements including wear and corrosion resistance.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.642-646
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• 2008

Signaling system, for which ensuring safe train operation, must be a fail-safe system with higher reliability and safety. TCS has made significant improvements both on signaling system, from relay based ground signaling system to computer based on-board system, and on driving mode, form low speed and low density driving to TCS supporting high speed and high density driving. In addition, TCS has been applied to rolling stock with a wide variety of context according to the characteristics of rolling stock or railway infrastructure. In this paper, therefore, we confirmed the basic concept of ATC system and analyzed its development process in technology context via referencing international cases and ATC systems introduced and applied in Korea. Based on those analyses, we suggested the new TCS development strategy for its suitable application to high speed line, conventional line and metro, and we also provided technical considerations related to TCS application.

• Solar Energy
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• v.18 no.4
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• pp.33-38
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• 1998

This paper reports the experimental results concerning the thermal performance of a freeze-protected direct solar water heating system. The direct system tested has been manufactured to prevent any breakage during harsh wintry conditions by specially designed riser and downcomer headers capable of relieving extra pressure due to freezing of water. The direct system tested has shown 10% improvement in its efficiency over that of a indirect type system using antifreeze as the heat transfer medium. It is felt that any direct system of its kind could galvanize the whole solar industry if further improvements are made to ensure its durability.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.7
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• pp.1290-1294
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• 2016

In this study, we investigate the sources of system malfunctions by measuring and diagnosing various surges and noise signals from grounding systems for electrical and electronic systems and installations in order to ensure the reliability and stability of the system operations. We measured performance or structural problems detected in the grounding systems currently in operation and analyzed the measured data in order to eliminate noise currents and interferences causing the systems to malfunction and be damaged. Based on the analysis results, we proposed improving grounding systems and the wiring arrangements most appropriate for the grounding systems and carried out the installations as per the proposed engineering. We verified that the proposed engineering made the status of system operations improved by measuring the ground noise signals during the system operations and comparing them before and after improvements being carried out.

• Journal of Game and Entertainment
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• v.2 no.2
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• pp.70-74
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• 2006

In this paper I present a system that with infrared vision sense tracks the position and orientation of a wireless object on a tabletop display surface. The system offers two types of improvements over existing computer vision tracking approaches. First, the system tracks an object accurately without susceptibility to changes in lighting conditions. Second, the system tracks not only the orientation but button click state of the object. This system can detect these changes in real time. Finally, I present an application of the system : Color Lab Box.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.129-130
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• 2022

This study is conducted to identify improvements in the setting time estimation system through the Mock-up test of the finishing automation system and the setting estimation system. As a result of the study, it is necessary to adjust the spring strength of the setting time estimator and the diameter and length of the estimation needle so that the value of the hardness can be measured from 15HD to around 40HD.