• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05c
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• pp.199-202
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• 2002

During normal operation, partial discharge(PD) tests were performed using turbine generator analyzer(TGA) in high voltage motor. Epoxy-mica couplers are installed at motor terminal and analyzed PD signal using TGA. #A motor stator insulation is good because small partial discharges are detected. PD pattern show that PD occurs in insulation. PD of #B motor is larger than that of #A motor and PD pattern show that positive PD larger than negative PD. It means that PD occurs between insulation and slot. And A phase PD magnitude of #B motor is large and high compare with any other phase. Therefore wedge, core and slot of #B motor need to check and repair.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.26 no.2
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• pp.251-256
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• 2017

This study developed an image processing system for detecting damages on underground spiral PVC pipes. The detection method is simple-identifying damaged areas by measuring circularity along the pipeline. This uses the assumption that damage parts will not make a circular shape. Conventional devices check the circular shape of the pipe along the pipeline by measuring the angles between 6 spring-connected legs on the device. The conventional device, however, requires the insertion of 3 different wires (electrical, communication, and camera lines) along with a guide wire for pulling the device. The developed system presented here has simplified this system, requiring only a camera line while maintaining reasonable accuracy in damage detection.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.6
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• pp.112-118
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• 2001

In this study the leakage current measurement method based on a porous ceramic is applied to check the conductive substance caused by the ionized particles. By using engine and chassis dynamometer and an experiment vehicle, in which the hydrocarbon sensor (HC sensor) was exposed to the exhaust gas to create the electrical signal, the HC sensor in the exhaust line checked the conductive ions in emission gas. Generally the output electrical signal of HC sensor is followed with amount of hydrocarbon in the experiments in cold start and operation. By combining the electrical signal, a measure of conductivity of exhaust gas with hydrocarbon can be provided by OBD (On Board Diagnosis) II and EMS (Engine Management System).

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.116-118
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• 2001

It is important to determine of tower type whether suspension or tension tower in overhead transmission lines. When we select to tower type, we have need to check of swing angle for suspension string sets. And jumper wire of T/L in the strong wind area have to analysis of swing angle in order to clearance or length of tower arms. This paper is summarized the methods to calculate of swing angle for suspension string sets and jumper wires, and is calculated the swing angle. The calculated result have proposed to improved design specifications of overhead transmission line.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.51
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• pp.139-149
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• 1999

Developed in this paper is a prototype extranet using mobile device such as Personal Digital Assistance(PDA) or Handheld PC(HPC). Especially an adjustment transaction system for auto insurance using wireless data communications is described. Using infrastructures such as PCS, Cellular, Private Radio, wireless communications offers tremendous applications in Korea. A survey of such applications is presented in this paper. Also an analysis of currently available infrastructures of wireless communications is described in this paper. The scheme of an adjustment transaction consists of seven steps: (1) get list of adjustment, (2) obtain insurance information, (3) check police record, (4) get an accident record, (5) get bluebook value, (6) examine the car, (7) file report. Comparing with the previous on-line method that spends much time on gathering data, the proposed system guarantees more rapid transaction using wireless communications.

• ETRI Journal
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• v.35 no.2
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• pp.253-258
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• 2013

We propose and demonstrate an efficient power-saving optical network unit (ONU) based on upstream traffic monitoring for 10-Gb/s wavelength division multiplexed passive optical networks (WDM-PONs). The power-saving mode controller uses a ${\mu}$-processor and traffic monitoring modules followed by the proposed power-saving processes to operate the sleep mode ONU. The power consumption of the ONU is effectively reduced from 19.3 W to 6.4 W when no traffic from the users is detected. In addition, we design a power-saving mechanism based on a cyclic sleep mode operation to allow a connectivity check between the optical line terminal and ONU. Our calculation results show that the WDM-PON ONU reduces the power consumption by around 60% using the proposed mechanism.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.258-263
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• 2005

Because of its high performance and accuracy, electron beam welding has an important role in industrial applications such as semi-conductor and LCD manufactures. Since its operation has been done in a vacuum room, it is very difficult to check out their weldability as well as the correct welding area of the specimen. In this study, a measurement system of the electron beam welding has been developed based on the 3-axis LVDT controlled table. In addition, the algorithm to tracking the welding line has been developed. Welded regions were measured by using an A-scan ultrasonic sensor only. Weldability of the aluminum specimen has been tested by newly developed measuring system. The results are compared with those by using an C-scan ultrasonic sensor, which show good agreements with each other.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.11
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• pp.1-6
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• 2002

This study is about optimization of Laser Repair Condition in EDS Line to improve AC and DC characteristic of high speed DRAM. The margin of AC parameter can be improved by forcing the proper DC generator levels and also improved by cutting the optional fuse about characteristics.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.153-156
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• 2000

To reduce the maintenance expense, and the possibility of electric outage and accident, we should optimize the outdoor insulation system. And for the optimization, accurate measurement for the degree of contamination with climatic conditions, such as wind, rain, and drought, should be carried. However the classical measuring method, brush wiping, has some problems in the aspect of man power, reliability, and expense. In this paper, we propose two type apparatus, which could detect the degree of contamination on insulators in outdoor insulation system, such as transmission and distribution line insulator and bushing. One use the leakage current, and the other use the oscillating frequency to check the degree of contamination. To avoid the oxidation of electrode AC source, and the low degree of contamination was applied. From the result of this investigation we could get the good relationship between the degree of contamination and the leakage current and oscillating frequency

• Korean Institute of Interior Design Journal
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• no.9
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• pp.10-17
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• 1996

With the ever-increasing important of high-speed information in society as we move towards the 21 st century. Interior design and it's working condition has been changed a great deal included a sort of each special character and make a difference against the others. It used to be find a great poles asunder of worker's safety and project quality according to the environmental dimension of interior construction field as if they should be a pleasantness or poor condition. This research aimed to improvement of environmental construction field of interior with construction engineers and particular interior labors in 4 phases as : ⅠThe preparatory phase : -Secure a Budget, Environmental safety supervisor -Fix of Design quality, Construction period. -Choice of Construction method, Sub constructing Ⅱ. Starting work phase ; -Capacity , Safety of temporary power line. -Carriage, Stock of Material -Safety of Electronic tools, -Personal protector. Ⅲ. Working period ; -Ventilation, I illumination of working place. -Measurement of environmental working condition Ⅳ.Finish working phase ; -Analysis of measurement data. -Evaluation and making up for the weak point. -Keeping data.