• The KIPS Transactions:PartB
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• v.11B no.3
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• pp.345-352
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• 2004

This paper deals a method to deliver more realistic sound by cancelling the cross-talk which is inherent to the 5.1 channel speaker system. The acoustical model for cross-talk cancellation is the free field model. This model minimizes distortion of sound. 1 used the bark scale sound quality compensation which based on psycho-acoustic. For the surround channels, band-limited sound quality compensation is performed in the frequency domain. I also performed the sound qualify assessment test on the traditional 2 channel stereo and 5.1 channel system. This test is performed in the tort chamber which satisfies the ITU-R specifications. 1 uses the IACC(Inter-Aural Cross-Correlation) to determine the preferences of the amateur and the golden ear experts to asses the trans-aural filter. According to the result from the proposed method, I got more the 38dB separation rates with the Dolby standard speaker array. The results on the diffusion by the subjective test with the experts shows 0.4∼0.5 point Increased then before.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.584-588
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• 2021

The impedance of the speaker is likely to be recognized as a fixed value. However, speaker impedance continues to vary with frequency variation, especially larger in resonant frequency region. The sound pressure level of loudspeakers is determined by the current flowing throughout the coil that consists loudspeakers. If loudspeakers are driven by voltage, sound pressure level of the loudspeaker is distorted by the variation of loudspeaker impedance. Current-drive of loudspeakers can solve this problem, but distortion of sound pressure level occurs in low frequencies due to resonance. The distortion can degrade the sound quality of the sound system. So to solve this problem, In this paper, we propose a resonance compensation circuit using DSP. we simulates audio systems using an equivalent model of loudspeakers to verify distortion of sound pressure level due to impedance variation and propose a circuit to compensate it. The proposed circuit is configured using a state variable filter and it can adjust the center frequency and output, so it will be used various sound systems.

• Journal of Satellite, Information and Communications
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• v.8 no.4
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• pp.17-20
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• 2013

In this study, we introduce an LED Driving circuit in order that the information state can indicate audio signal gain and radiate pattern of ultrasonic speaker system for a sign board. Ultrasonic speaker system decreases energy loss and transmits the sound farther. Ultrasonic speaker having such characteristics is useful in that it can be widely used in daily life. Additionally, Proposed LED circuit indicates the information state as linear LED brightness taken from interface of ultrasonic speaker system. Designed circuit is confirmed through $0.35{\mu}m$ CMOS process by Dong-bu.

• The Journal of Korea Robotics Society
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• v.3 no.3
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• pp.165-175
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• 2008

For an advanced intelligent service, the need of HRI technology has recently been increasing and the technology has been also improved. However, HRI components have been evaluated under stable and controlled laboratory environments and there are no evaluation results of performance in real environments. Therefore, robot service providers and users have not been getting sufficient information on the level of current HRI technology. In this paper, we provide the evaluation results of the performance of the HRI components on the robot platforms providing actual services in pilot service sites. For the evaluation, we select face detection component, speaker gender classification component and sound localization component as representative HRI components closing to the commercialization. The goal of this paper is to provide valuable information and reference performance on appling the HRI components to real robot environments.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.939-946
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• 2008

본 논문은 시청자의 위치에 최적화된 입체음향을 제공하는 TV 개발에 관한 것으로 2 개의 TV 스피커만으로 5.1 채널 스피커가 주는 입체음향 효과를 제공해준다. 기존의 Speaker Virtualizer 기술은 시청자가 특정 위치(Sweet Spot)를 벗어나면 입체음향 성능이 현저히 저하된다. 반면, 본 논문에서 제안하는 Adaptive Virtualizer 기술은 초음파가 장착된 리모콘을 사용하여 시청자의 위치를 인식하고 인식된 시청자의 위치 정보를 활용하여 청취위치에 해당하는 HRTF로부터 설계된 Filter를 Update 하고 두 스피커의 출력레벨 및 시간지연 값을 보정함으로써 최적의 입체음향을 재현한다. 본 논문에서는 실시간 구현을 위해 Speaker Virtualizer의 계산량을 최소화하는 기술을 제안하고 다양한 청취 위치에 해당하는 Filter를 설계하고 설계된 Filter를 효율적으로 Update 하는 Adaptive Virtualizer 기술을 제안한다. 또한, 초음파를 이용한 시청자 위치 인식 기술 및 전체 시스템 통합 기술을 제시한다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.183-188
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• 2003

This study is to make the fundamentals of sound quality evaluation in regard of acoustical characteristics of passenger compartment. The deviation of frequency response function level within audible frequency is evaluated at receiving point in the research of room acoustics. In this study, frequency response function is the one between speaker and driver's ear positions. The positions of driver and audio speakers are optimized by analysis of acoustic mode of acoustic cavity. The main reflection planes are determined by analysis sound ray path diffused at optimized speaker positions. Finally, designer selects acoustical material by analysis of absorption effect of acoustical materials on the main reflection planes in order to avoid to distortion and fluctuation of frequency response function..

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.4
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• pp.1-8
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• 1996

The sound quality of the car audio system is affected by the serveral factors such as the dimensions of the room, the boundary condition of the wall, the location of the speakers, etc. Among these factors, the location of the car speakers has been focused to find the best location of the car speakers assuming that the flat response is better. To verify the suggestion, the subjective test is adopted using 10 people. The developed method is utilizd to evaluate the function of the audio system with fixed speaker position.

• Electronics and Telecommunications Trends
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• v.22 no.2 s.104
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• pp.31-37
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• 2007

인간로봇 상호작용 기술(human-robot interaction)은 다양한 의사소통 채널인 로봇카메라, 마이크로폰, 기타 센서를 통해 인지 및 정서적으로 상호작용할 수 있도록 로봇시스템 및 상호작용 환경을 디자인하고 구현 및 평가하는 지능형 서비스 로봇의 핵심기술이다. 본 고에서는 오디오 기반 인간로봇 상호작용 기술 중에서 음원 추적(sound localization)과 화자인식(speaker recognition) 기술의 국내외 기술동향을 살펴보고 최근 ETRI 지능형로봇연구단에서 상용화를 추진중인 시청각 기반 음원 추적(audio visual sound localization)과 문장독립 화자인식(text-independent speaker recognition)기술들을 다룬다. 또한 이들 기술들을 가정환경에서 효과적으로 사용하기 위해 음성인식, 얼굴검출, 얼굴인식 등을 결합한 시나리오에 대해서 살펴본다.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.1239-1242
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• 1998

In television stereo system, to produce a realistic sound effect is very difficult because the distance between stereo speakers is very narrow. Many signal processing methods of widening the sound image for spatial impression have been studied. One of the methods of widening the sound image is using the Precedence Effect by reflected sound. However, this method does not work effectively in lower frequencies because of directivity of a speaker. In this paper, we propose an effective method of expanding stereo image using Precedence Effect and Phase Shifting method to produce a whole band frequency sound expansion. In experiments, we confirm the usefulness of the proposed stereo sound image expansion system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.04a
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• pp.132-133
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• 2013