• Proceedings of the Acoustical Society of Korea Conference
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• 1992.06a
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• pp.141-146
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• 1992

• 한국전산유체공학회:학술대회논문집
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• 2008.08a
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• pp.29.4-29.4
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• 2008

• The Magazine of the IEIE
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• v.28 no.11
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• pp.79.2-80
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• 2001

• The International Journal of Costume Culture
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• v.8 no.2
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• pp.71-84
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• 2005

Fibulae have been used as clothing fasteners throughout history. They were especially popular with the Celts, but were also used by the Greeks, Romans, Saxons, and Vikings, to name a few. The earliest examples are found in the Mediterranean and Middle East, and date from 800 B. C. and earlier. Their use continues today, in the form of the modern safety pin. The first fibulae of the Bronze Age were very simple, much like modern safety pins. The form of this small functional object varies from simple to extravagant since it is also seen as a piece of jewelry, and is thus subject to the evolution of style. Its size depends on the thick/Jess of the clothing to be attached. Its fabrication demonstrates a great mastery of metal work. Fibulae would vary with the taste and wealth of the wearer. The Fibulae were divided into 10 styles according to the shape, Fibulae with Safety pin shaped style, Penannular shaped style, Animal shaped style, Diamond shaped style, Radiated head shaped style, Horsefly shaped style, Arched bow shaped style, Fan-shaped style, Trumpet shaped style, Arched-fan shaped style.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1882-1884
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• 2004

In this paper, the waveform parameters of electromagnetic pulses radiated from intracloud discharges were presented. The zero-crossing times and the full pulse widths of the large bipolar electromagnetic pulses due to intracloud discharges are gradually decreased as the stroke proceeds. Also, the electromagnetic pulses tend to be bipolar, with narrow and fast leader pulses superimposed on the initial half cycle. The mean numbers of leader pulses superimposed on the initial half cycle were 1.61${\pm}$0.74 and 1.75${\pm}$0.73 for the positive and negative polarities, respectively.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.504-508
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• 2004

An EMC analysis of a switched mode power supply (SMPS) have been usually using unbalance circuit topologies and the major factor of disturbance is parasitic capacitance. We have proposed a balanced switching converter circuit, which is an effective way to reduce the common mode conducted noise. In this paper presents the relationship between common mode current and radiated field.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.237-242
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• 1999

In this study, a design method using plane actuator is developed to make new speaker system, whose shape is much thinner than that of conventional loudspeaker. Piezofilm(PVDF) is used as plane actuator of flat speaker. To avoid the distortion of sound radiated from flat speaker, the frequency response of radiated sound to be flat is taken as the design objective. The electrode pattern and orientation angle of piezofilm actuator is optimized to satisfy the design objective. The formulation is based on the coupled finite element and boundary element method. Genetic algorithm is used in the optimization process, which is useful in the optimization of discrete design variables. Frequency response with optimized piezofilm actuator is made flat enough to satisfy the design objective. For the enhancement of sound power, double-layered piezofilm actuators are also considered. The sound power with double-layered actuator becomes larger than that with single-layered actuator as expected.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.9
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• pp.1013-1020
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• 1992

The conductivity variation of a high resistivity bulk silicon semiconductor, whose electrodes were deposited with aluminum vapor, was studied experimentally by measuring the X-ray intensity and current flow, which was developed by X-ray radiation while applying a pulse voltage to the silicon, in a load resistor connected to the semiconductor. The current flow observed immediately as the X-ray radiated, and when the X-ray decreased. It was found from the observation of switching current for the X-ray intensity and the voltage applied in the semiconductor that the switching current of the semiconductor increased as the intensity of the X-ray and the applied voltage increased. In case of lower applied voltage, the switching current for higher applied voltage depended on the intensity of the X-ray radiated due to the saturation of electron and hole.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.4
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• pp.753-761
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• 1998

The determination of sound pressure radiated from periodic plate structures is fundamental in the estimation of noise level in aircraft fuselages or ship hull structures. As a robust approach to this problem, here a very general and comprehensive analytical model is developed for predicting the sound radiated by a vibrating plate stiffened by periodically spaced orthogonal unsymmetrical beams subjected to a sinusoidally time varying point load. The plate is assumed to be infinite in extent, and the beams are considered to exert both line force and moment reactions on it. Using this theoretical model, the sound pressure levels on axis in a semi-infinited fluid (water) bounded by the plate were calculated using three numerical tools such as the Gauss-Jordan method, the LU decomposition method and the IMSL numberial package. Especially, the variation in the sound pressure levels and their modes were investigated according to the change in frequency, bay spacing and bay distance.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.375-380
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• 2005

In this paper, We studied an antenna for the wireless home network service. From the structural modification of patch and ground plane, we made a reverse heart shape radiated pattern of antenna which is suited to wireless home network service. As a result, bandwidth between maximum gains is 110 degree, and the difference of downward direction gain from maximum gain have become -3.6dB. Installing the antenna on the ceiling, horizontal plane of the inner home will be formed the uniform electromagnetic environment. Accordingly, stable reception level acquisition and outdoor radiated suppression could be possible.