• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.107-110
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• 2005

This paper describes the design and fabrication of synchronous clock recovery module for S-DMB Gap Filler. Using the 2.304MHz TTL signal from gap filler tuner, clock recovery module with 10MHz output frequency including holdover function is designed. The measured performance of the clock recovery module shows a stability of less than 0.01ppm, 29 sec stability time, 10 sec holdover time, and maximum -113dBc/Hz@100Hz phase noise.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2003.06a
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• pp.121-122
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• 2003

• 연구논문집
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• s.23
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• pp.15-27
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• 1993

The single crystal specimens were solidified by modified Bridgeman method. The surface recrystallized single crystal specimens were prepared by shot peening followed by heat treatment. The surface recrystallization begins at the dendrite cores on the surface. The recrystallized grains grew into the inner side of the specimen. The growth of recrystallized grains was inhibited by the pores and eutectic phases. The primary $\gamma'$ phases were dissolved at the recrystallized grain boundaries during the grain growth. The grain growth of recrystallized grains was similar to the cellular type transformation. No orientation relationships were found bewteen the recrystallized grains and the parent phase.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.535-539
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• 1989

A high-frequency asymmetrical PWM control technique is proposed which can improve the input power factor of ac chopper and also suppress its harmonic contents of currents at both its input and load sides and the acoustic noises by its switching semiconductor devices. The ideal switching function for the proposed technique is derived and hence converted into asymmetrical PWM pattern for practical implementation of ac voltage regulator. Also the various power circuits of three phase AC choppers are suggested. The theoretical characteristics of the proposed PWM technique are investigated by digital simulation.

• Proceedings of the KIEE Conference
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• 1999.07f
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• pp.2584-2586
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• 1999

The purpose of this paper is to verify the appropriation of power electronics circuit by applying the most powerful and widely used simulator PSPICE and SIMULINK for adapted variable control technics. Power semiconductor macro modeled by SIMULINK such as DC motor and AC induction motor. Furthermore DC motor & AC induction motor are modeled by PSPICE through their algorithms. For proved these modelings accurate, simulation techniques which are generally used in the field of power electronics circuits are adapted in power electronics and systems

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.431-435
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• 1998

This paper deals with the output characteristics of resonant PWM inverter type X-ray generators connected to different DC power units i.e. a single phase full bridge rectifier, a three phase full bridge rectifier and a power storage unit(PSU). The quality of X-ray beam depend on the pulsation waveforms of DC voltage supplied to the X-ray tulbe. In a X-ray generator, the waveforme of DC output voltage can be affected from hramonic distortion of DC input power. When a tube voltage waveform is distorded, the property of X-ray beam such as reproducibility, direcibility and doesage can be reduced. Therefore, we compared DC output waveforms and doesages with three thpe of DC power units and show the experimental results in this paper

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.304-309
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• 1998

In this paper, authors introduce an application of a nonlinear rotor flux observer, known under the name of ELO(extended Luenberger Observer), for direct rotor field oriented control(DRFOC) of induction motor. ELO requires no solution of nonlinear partial differential equation for its coordinate transformation and linearization used for the nonlinear observer design. Its simulation results concerned to different level of unknown variables of load torque and rotor resistance show high accuracy on rotor flux estimation in steady state.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.219-220
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• 2012

Steel method compared with conventional aluminum truss construction materials as the biggest difference, aluminum truss method by using an aluminum material construction of the existing steel truss compared with the welding operation is omitted, as the air operations will be reduced by about 40% do not need skilled workers in the existing portion of each tube and cost 11,233 to 13,173 won/㎡ cheap it was found.

• Journal of Korean Foot and Ankle Society
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• v.13 no.1
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• pp.106-108
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• 2009

Calcaneus fracture with a subtalar dislocation are extremely rare. A case of a joint depression type calcaneus fracture with a lateral dislocation of the calcaneal posterior facet and tuberosity is presented. We treated it with open reduction and internal fixation with Steinmann pins and K-wires through limited posterior approach and obtained satisfactory radiographic and clinical outcome.

• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.356-360
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• 1990

This paper is an application of Modern control Theory to the control of a current-source inverter (CSI) fed Induction Motor Drive System. A Linear Quadratic-Gaussian (LQG) scheme is developed, in which the Kalman Filter is tuned for high robustness by a method due to Doyle and Stein(8). The design is carried out for a sample system and the robustness by analysis and computer simulation.