• Journal of Industrial Technology
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• v.19
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• pp.1-7
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• 1999

This is the pre-study to pile up the basic technique for the electro-discharge machining in the field of micro-drilling. The machined chips are flowed out from the machining area by the flow arisen from the high speed rotation of the electrode. The cylindrical shape electrode, whose diameter is 0.5mm, is clamped by the three point clamping type clamper and the clamper is attached at the front shaft of the high speed rotating DC motor. The current for machining is controlled by pulse width modulation technique and the machining conditions such as frequency and duty ratio are changed to find out the effect of the variables for machined results.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.228-233
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• 1999

In this paper we develop an electronic starter circuit that is suitable for Neon sign operation of switch-start fluorescent lamps. The developed starter enable single pulse ignition of fluorescent lamp at the peak point of preheating current, irrespective of the position of the Tum-On signal. This is possible due to the sequential operation of two transistors different in their operation characteristics and a diode operation characteristic. The switching endurance test using this starter has been carried for more than 3000 hours for a single switch-start on a severe blinking condition of preheating of 0.1s and of successive lighting interval of 0.1s.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.13-14
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• 2010

The active clamp forward converter provides zero voltage switching and low voltage stress in wide input voltage range. It has a high efficiency at a high switching frequency and the clamped energy is recovered to the input stage. It is available for the power adaptor circuit of notebook computer. The adaptor with 19.5V/200W output power is designed for notebook computer. Specially, it is considered the transformer properties of the converter in design process. The organized process is checked by the validity from the test of the active clamp forward converter.

• Proceedings of the KIEE Conference
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• 1999.11b
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• pp.58-60
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• 1999

In the industrial field the necessity of the linear motion is increasing. We selected a moving magnet coreless type LDM, which have the advantages, such as long stoke, brushless, no cogging force. Actually, the design is accomplished using FEM analysis for the basic configuration of a magnetic circuit, and characteristic equations for coil design. In the course of design, we have estimated airgap flux density and thrust. We fabricated coreless type LDM and experimented static test. We compared measurement values with FEM analysis values.

• The Journal of Korea CHUNA Manual Medicine
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• v.6 no.1
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• pp.11-20
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• 2005

Objectives: To find relation with training period and body composition of peoples engaged in training program of six weeks and present a better training formula. Methods: Changes of body composition during training were analysed with paired t-test. correlation of training period and body composition were analysed with simple correlation analysis. Results: Body weight, body fat and body fat ratio were decreased significantly, all of them were concerned in training period. Conclusions: Training program of six weeks reduce body weight, body fat ratio even muscle mass. It should be careful to order training prescription.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.51-52
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• 2006

Gabion can be used for the purpose of preventing overflow of river and side loss of road. However the manufacturing process of the gabion is manually controlled especially to the joining process at the terminal part of gabion with small diameter wire. In this paper automatic feeding guide system was designed and fabricated to make automation. The fabricated system was tested in the factory level. Pneumatic system was considered as the main idea of the feeding system. 3/2-way and 5/2-way manual control valve, eight double-acting cylinders were used. Based on the theoretical simulation and actual test the fabricated system was well controlled. The system was applied to the patent.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.774-777
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• 1988

This paper covers the insulation coordination of 765 KV transmission line in Korea Electric Power Corporation. The design for the lightning, switching surge, and contamination was conducted to increase the reliability of 765 KV line. The authors have used the result of a limited Westinghouse ANACOM swiching surge study of the Korea Electric Corporation's 765 KV Expansion plan. The study investigated the switching surge overvoltage distribution and maximum switching overvoltage when relosing 765 KV lines. They used the technical data of the suspension insulator for the contamination design, which was available from a foreign insulator manufacture. From this paper, the authors find out that the contamination design dominates to determine the number of insulator and the SOV design dominates the air clearance in the tower. Afterwards the authors will confirm this design by Demonstration Test with Korea Electro-technology Research Institute.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.11
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• pp.628-634
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• 2002

A capacitor-charging power supply using high frequency inverter technology is strongly recommended for the charging section of the pulsed power supplies. A high frequency inverter swiching makes the overall system size small. The command-charging feature can guarantee the higher reliability of switching function. The protection circuit can be easily included in the system and the good regulation of charging voltage can be acieved by the feedback system. Several modules can be stacked to supply required output power and a failed module can be easily replaced. A 50-kV, 35-kW capacitor charging power supply is developed. In this paper the detailed design and test results of a prototype unit are presented.

• Proceedings of the IEEK Conference
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• 2002.06d
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• pp.81-84
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• 2002

This paper presents the real-time PCB(Printed circuit board) inspection system that can detect thin open/short error using the line scan camera. After a overall introduction of our system, the outline of our inspection methods are described. The goal of our inspection system is the real time and detailed inspection using the line scan camera. To perform inspection processing in real-time, we utilize double buffering structure. In order to solve the problem of unexpectable pixels of PCB, we propose melting process which eliminates unexpectable pixels of PCB. The design and development of our prototype of PCB ins- pection system is discussed and test results are presented to show the effectiveness of the developed inspection algorithm.

• IEIE Transactions on Smart Processing and Computing
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• v.2 no.4
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• pp.216-225
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• 2013

This paper discusses the issues regarding an abnormal V-shaped error confronting algebraic-based deconvolution process. Deconvolution was applied to an analysis of the effects of the Random Telegraph Noise (RTN) and Random Dopant Fluctuation (RDF) on the overall SRAM margin variations. This paper proposes a technique to suppress the problematic phenomena in the algebraic-based RDF/RTN deconvolution process. The proposed technique can reduce its relative errors by $10^{10}$ to $10^{16}$ fold, which is a sufficient reduction for avoiding the abnormal ringing errors in the RTN deconvolution process. The proposed algebraic-based analyses allowed the following: (1) detection of the truncating point of the TD-MV distributions by the screening test, and (2) predicting the MV-shift-amount by the assisted circuit schemes needed to avoid the out of specs after shipment.