• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.175-178
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• 2004

각각 2개의 마이크로폰을 내장한 귓속형 보청기를 양쪽귀에 착용한 상태에서 소리의 지향성을 시뮬레이션하고 전기음향실험으로 비교하였다. 지향성 보청기의 신호 대 잡음 비율 향상을 고려하였다. 시뮬레이션을 위해 경계요소기법을 사용하였으며 본 논문에 의해 밝혀진 주파수 대역에서의 시간 지연을 DSP칩을 내장한 디지털 보청기의 지향성 조절 파라미터로 사용하고자 한다. 마이크로폰 사이의 간격을 10mm로 하였다. 가장 최적한 지향성이 출력 되기 위한 위상을 계산하였다.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.432-435
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• 2007

In this paper, a dual band microstrip patch Antenna is designed for RFID Application. The antenna shows a good performance at the frequencies, 900MHz and 2.45GHz for the radiation characteristics and input impedance matching, as well. The reflection factor is lower than -25dB and a good directivity higher than 5dB is achieved for both frequency.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1998.04a
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• pp.267-272
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• 1998

A new signal processing technique, the directional harmonic wavelet map(dHWM), is presented to characterize the instantaneous planar motion of a measurement point in a structure from its transient complex-valued vibration signal. It is proven that the auto-dHWM essentially tracks the shape and directivity of the instantaneous planar motion, whereas the phase of the cross-dHWM indicates its inclination angle. Finally, the technique is successfully applied to an automobile engine for characterization of its transient motion during crank-on/idline/engine-off.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.639-642
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• 1998

This paper proposes a new wide-band beamforming which has guassian weighting. For the prupose of measurement this beam is formed by using all sensors toghether, not octave-by-octave. Weighting is applied to each sensor before time-delay compensation as a frequency-dependent function. As the resutls of the simulation of the proosed algorithm for nested linear array having 17 sensors for each octave, it is confirmed that beam can be formed with all sensors together and uniform directivity index can be achieved by proposed algorithm.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.995-998
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• 2002

In this paper, we present a fast algorithm for hand gesture recognition of a human from an image by using the directivity information of the fingers. To implement a fast recognition system, we applied the morphological shape decomposition. A proposed gesture recognition algorithm has been tested on the 300 ${\times}$ 256 digital images. Our experiments using image acquired image camera have shown that the proposed hand gesture recognition algorithm is effective.

• ETRI Journal
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• v.28 no.6
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• pp.796-798
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• 2006

This letter proposes a tapered stacked microstrip antenna for application in small unmanned aerial vehicles (UAVs), which has advantages in mountainous terrains. With its tapered structure and increased bandwidth designed to operate at the resonance frequency of 2.4 GHz, the proposed antenna improves directivity, accuracy, and precision of small UAVs. The test flight results show the proposed tapered antenna has a three times higher impedance capability of 350 MHz based on VSWR<2. The transmission pattern is also more reliable than that of previous antenna designs.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2000.11a
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• pp.399-403
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• 2000

A new type of collinear antenna called short-ended coaxial slot-coupled strip array antenna is investigated theoretically. The antenna has an advantage of structural simplicity. The integral equations are derived for the proposed structure by use of the Fourier transform and mode expansion, and the simultaneous linear equations are obtained. The slot electric field and strip current are then obtained by solving the simultaneous linear equation. The effects of slot and strip number on the radiation efficienty, beamwidth and directivity gain are also presented.

• Proceedings of the IEEK Conference
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• 2003.11b
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• pp.95-98
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• 2003

DCT or Wavelet based on Image compression technique occurred to compression artifact. In order to remove this problem, we can apply many improvement algorithms. But in these cases, these algolithms resulted in bad results against the good quality image. Therefore this paper proposes an automatic image interpretation technique not to apply to the good quality images. In this paper, we exploit the basic nature of DCT.

• Journal of Sensor Science and Technology
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• v.8 no.4
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• pp.298-307
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• 1999

This paper describes the application of the coupled FE-BEM (finite element-boundary element method) for the numerical harmonic analysis of the linear dynamic behaviour of a magnetostrictive Terfenol-D rod in water. The magnetostrictive rod is three-dimensionally simulated to transduce applied electric current in a helical coil around the rod to mechanical displacement. The theoretical derivation of the magnetostrictive matrix equation is described in detail. The steady-state resonance response of the displacement is shown. In addition, the directivity pattern and the radiation impedance are also shown.

• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.883-885
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• 2010

다양한 홀에서 물리적으로 운동하는 사운드를 미리 예측한다는 것은 매우 어려운 일이다. 자유롭게 운동하는 사운드를 예측/분석할 수 있는 과학적인 소프트웨어는 사운드 엔지니어에게 많은 도움을 준다. 소리의 물리적 운동 방향(Sound Directivity), 거리에 따른 타임 딜레이(Time Delay), 스피커의 각도와 적정한 SPL(Sound Pressure Level)을 과학적인 근거에 의해서 정확한 값을 산출하여 음향 장비 설치이전에 미리 예측하여 음향 디자인을 완성한다면 시간과 비용을 획기적으로 줄일 수 있다. 본 연구은 현재 개발 과정에 있거나 혹은 사용되어지고 있는 소리 예측 프로그램을 분석하여 보다 진보된 소리예측 프로그램을 개발하고자 함이다.