• Journal of the Korean Society for Precision Engineering
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• v.18 no.4
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• pp.9-18
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• 2001

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.1071-1072
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• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.169-170
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• 2008

• Proceedings of the Materials Research Society of Korea Conference
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• 2006.05a
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• pp.19.2-19.2
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• 2006

• Journal of applied mathematics & informatics
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• v.37 no.3_4
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• pp.271-279
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• 2019

We investigate how a feedforward neural network works to separate a geometric region from its complement. Our investigations are restricted to regions in ${\mathbb{R}}$ or ${\mathbb{R}}^2$ including an interval, a triangular region, a disk and the union of two disjoint disks. We also examine what happens at each layer of the network.

• Journal of the Chungcheong Mathematical Society
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• v.36 no.1
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• pp.25-37
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• 2023

In this paper, we consider the Landau-de Gennes energy functional for liquid crystals confined in a thin cylindrical domain and study defects of molecular directions in the system by applications of external fields.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.370-372
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• 2004

This paper addresses the wavelet-based fuzzy PI/PD controller design using DNA coding method. A structure of fuzzy controller model is adopted as the wavelet transform of which the coefficients are identified. The proposed method overcomes some mathematical limits of conventional methods by using the fuzzy logic that is optimized by DNA coding method. The feasibility of the proposed fuzzy controller design scheme is verified by applying to the servo control of the optical disk drive.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.935-940
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• 2005

In this paper, dual rotor disk configuration with a coreless stator is proposed for the Lorentz force type integrated motor bearing system. An experimental compensation for the effects of high order harmonics is performed using the digital controller of the experimental setup. The runout profile and rotor unbalance are also identified by the extended influence coefficient method. The experimental results confirm that this compensation method effectively attenuates the rotor vibration all over the operating range of rotational speed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.264-268
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• 2005

In the semiconductor and optical industry the non-contact transportation is required for reducing the damages. The ultrasonic levitation is the solution of the problem. In this paper, the ultrasonic levitation system and 3 disk-type stator for levitating various object are proposed. The vibration modes of disks are analyzed with FEM and designed with the analysis results. The 3D vibration profiles of the disks are measured by Laser scanning vibrometer for verifying the vibration characteristics of the system and the amplitudes of the disks and the levitation heights of object are measured for evaluating the performance.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.861-864
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• 2005

Brake noise has been one of the most difficult concerns in the automotive industry. Although substantial research has been conducted to predict and eliminate brake noise, there is yet no method to completely suppress brake noise. Furthermore, little effort has been made to improve noise and vibration characteristics of the railway brake system. The amount of sound energy radiated from the railway brake system is much larger than that from the automobile, and it causes discomfort of passengers in the station. In this paper, noise and vibration caused by the braking force of the KTX vehicle have been measured and analysed. Results show that noise level increases abruptly right before a train comes to a complete stop. Furthermore, typical characteristics of the disk brake squeal have been observed.