• The Journal of the Acoustical Society of Korea
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• v.14 no.3
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• pp.82-89
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• 1995

A sound field simulator is constructed to obtain the sound field paramaters such as the magnitudes and directions of early reflections with moderate efforts. The proposed simulator is based on the hybrid ray tracing method that traces rays reached the listener position and convert them to image sound sources. By this approach, we can obtain the directional impulse response relatively easily with minimum casts. Simulation experiment results of several performace places are reported to how the versatility of the proposed simulator system.

• The Journal of the Acoustical Society of Korea
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• v.20 no.1
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• pp.36-42
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• 2001

This paper propose new sound localization algorithm that detects the sound source bearing in a closed office environment using two microphone array. The proposed Subband CPSP (Cross Power Spectrum Phase) algorithm is a development of previously Down CPSP method using subband approach. It first split the received microphone signals into subbands and then calculates subband CPSP which result in possible source bearings. This type of algorithm, Subband CPSP, can provide more robust and reliable sound localization system because it limits the effects of environmental noise within each subband. To verify the performance of the proposed Subband CPSP algorithm, a real time simulation was conducted and it was compared with previous CPSP method. From the simulation results, the proposed Subband CPSP is superior to previous CPSP algorithm more than 5％ average accuracy for sound source detection.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.11a
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• pp.21-24
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• 2007

보안이 중요시되는 공간에서 임의의 사람을 추적하고 인식할 수 있는 시스템의 필요성이 점차 중요시되고 있다. 본 논문에서는 wide-area를 감시하기 위해 음원과 Pan-Tilt 카메라를 이용하여 침입자 추적 시스템을 구현하고자 한다. 먼저 음원 추적 센서를 이용하여 음원의 방위를 검출한 후 Pan-Tilt 카메라를 방위 방향으로 이동시키고 이동된 Pan-Tilt 카메라로부터 기준영상을 추출한 후 일정 기준 시간마다 영상을 다시 획득하여 차 영상과 검출결과를 얻어 침입자를 추적하여 감시 시스템을 구현한다. 본 논문에 의해서 구현된 시스템은 홈 네트워크 보안 시스템과 연동을 하여 가정이나 공공시설 보안에 대한 인터페이스 역할을 할 수 있다.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1998.04a
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• pp.212-216
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• 1998

청취자가 음원의 위치와 방향을 감지할 수 있도록 원하는 지점에 음상을 정위시키는 일과 특정 공간내에서 방사되는 음원의 반사와 확산효과를 모델링하여 가상 공간 음향을 실현하는 일을 효과적으로 접목시키기 위한 3가지 유형의 입체음향 생성방법을 제시한다. 그리고 각 방법의 유효성 및 적합성을 검토하기 위해 실시한 심리음향 평가방법과 그에 대한 결과를 토대로 생성발법들간의 성능을 비교 평가한다.

• The Journal of the Acoustical Society of Korea
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• v.22 no.6
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• pp.482-488
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• 2003

Line may receiver contains an ambiguity on conjugate bearings, because of lacking aperture in transverse direction. To solve the left/right bearing ambiguity of line-array receiver we used line-array with cardioid beam. In addition, the synthetic aperture method adopts coherent processing of sub-aperture signals at successive time intervals in the beam domain. We presented performances about division of left/right bearing ambiguity according to array synthetic number of times in this paper.

• The Journal of the Acoustical Society of Korea
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• v.40 no.3
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• pp.247-253
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• 2021

Directional ultrasonic speakers that are used to hear sound only in a specific area have been continuously researched on various improvements in terms of sound quality and cost compared to general speakers. In this paper, we propose a DSP based hybrid-type ultrasonic speaker that can be heard at the same time as a general speaker in order to compensate for the sound in the low-band range, considering that it is difficult to hear the low-band sound below 500 Hz due to the sensor characteristics of the ultrasonic speaker. In the case of the system that is implemented by simply connecting a general speaker and an ultrasonic speaker, there are issues of high cost and difficulties of control as two amplifiers are used to playback ultrasonic and general sound sources. In addition, sound quality deteriorates due to the difference in playback time between ultrasonic and general sound sources. In order to improve issues of cost, control and sound quality, we developed hybrid-type ultrasonic speaker with a DSP based amplifier that can simultaneously playback by synchronizing the general sound source with the regenerated ultrasonic sound source, in addition to implement the existing CODEC functions such as Dynamic Range Control (DRC) and Equalizer (EQ).

• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.677-680
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• 2010

본 논문에서는 실용음악 전공자의 시창청음 교육을 위한 프로그램 방향을 제시하였다. 실용음악 전공학생들을 대상으로 한 설문을 통한 내부 환경 및 기존 교재에 관한 분석을 바탕으로 통합교과적 학습을 지향하는 시창청음 프로그램 개발 방향을 제시하였다. 시창과 청음 수업의 연계가 가능한 워크북 개념의 통합 교재로 문제의 방향을 설정하였으며 다양한 악곡의 활용을 통한 동기 유발과 학습 효과의 증대를 지향하였다. 교과 내용의 단순성을 지양하고 섹션별 학습을 추구하며 문제지와 답지를 교재 내에 포함시킬 것과 청음 워크북의 정답 부분을 음원 녹음한 오디오 CD를 제작하여 반복적 자기주도 학습이 가능하도록 하는 것이 주요 개발 방향이다.

• Journal of Satellite, Information and Communications
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• v.10 no.3
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• pp.22-25
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• 2015

This paper performs Color Code Control Connected with Sound Source and Sensitivity of PA Speaker facility attachable LED patch. PA speaker delivers the technology to control the color code of LED patch along the present PA speakers for the facility-attached, LED the development of the patch. PA speakers facility attachable color code control technology of LED patch detects the sound from the PA speaker using a check, and if the analog signal source is detected (sound source)by converting the digital signal passes to the main controller can control the color and pattern of LED patches. In this paper, based on the PA speakers LED color control system, sound emotional linkage-type, and follow the lead of the PA speakers through the feelings can effectively channel LED linked to the source type and proceed to experiment with color and emotion control, whether or not they offer via the color control technology LED patch availability. PA speaker facility attachble color code control technology of LED patch connected with the source and future research directions in the field, and as the application is expected to be able to be widely utilized.

• The Journal of the Acoustical Society of Korea
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• v.30 no.4
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• pp.197-206
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• 2011

In this paper, we proposes the virtual sound source panning algorithm in the multichannel system. Recently, High-definition (HD) and Ultrahigh-definition (UHD) video formats are accepted for the multimedia applications and they provide the high-quality resolution pixels and the wider view angle. The audio format also needs to generate the wider sound field and more immersive sound effects. However, the conventional stereo system cannot satisfy the desired sound quality in the latest multimedia system. Therefore, the various multichannel systems that can make more improved sound field generation are proposed. In the mutichannel system, the conventional panning algorithms have acoustic problems about directivity and timbre of the virtual sound source. To solve these problems in the arbitrary positioned multichannel loudspeaker system, we proposed the virtual sound source panning algorithm using multiple vectors base nonnegative amplitude panning gains. The proposed algorithm can be easily controlled by the gain control function to generate an accurate localization of the virtual sound source and also it is available for the both symmetric and asymmetric loudspeakers format. Its performance of sound localization is evaluated by subjective tests comparing with conventional amplitude panning algorithms, e.g. VBAP and MDAP, in the symmetric and asymmetric formats.

• The Journal of the Acoustical Society of Korea
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• v.13 no.3
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• pp.41-50
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• 1994

We studied an inherent error be caused by a measuring acoustic intensity using probe which can measure simultaneously the three-dimensional acoustic intensity. This three-dimensional intensity probe was constructed with four microphones, proposed by Suzuki et al. . In the computer simulation, we analyzed the nearfield measurement error with arbitary direction and each of axis direction on the ideal point source and the plate sound source which have finite size. From the results, in case of point source, we obtained accurate measurement below about 1dB when the distance of measurement was about 2.5 times with the distance among microphones in this probe. And in the case of plate sound source, the nearfield measurement error was decreased as the length of one side became above 0.02m, we obtained accurate measurement below about 1dB when the length of one side is 0.2m. The nearfield measurement error of finite size sound is small to ignore. Therefore this probe is useful to measure nearfield intensity.