• The Journal of the Acoustical Society of Korea
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• v.23 no.3E
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• pp.74-78
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• 2004

As analog audio systems are changing to digital systems, the DAB (Digital Audio Broadcasting) is expected to provide CD quality audio, various data services with interactiveness and excellent mobile reception ability. The DMB (Digital Multimedia Broadcasting), as more advanced successor of the DAB, adds video capability on the audio and data services. The DAB system assures high quality audio services even when the reception is through portable and mobile receivers. In this paper, USB-DAB receiver and PCI-DMB receiver are designed and implemented. The DAB receiver and the DMB receiver incorporate with PC to make use of computational power and application software of Pc. This enables the developed system to be more flexible and to meet various applications easier.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1997.11a
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• pp.63-67
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• 1997

The ISO(International Standard Organization) has standardized MPEG-2 audio. The MPEG-2 audio compression algorithm is based upon subband analysis and exploits the human auditory characteristics to achieve a low bit rate with minimum perceptual loss of audio signal quality. This thesis presents an enhanced MPEG-2 audio encoder using multiple TMS320C30 general purpose DSP's. The developed system is made up of five slave boards and one master board. Each slave board performs susband analysis psychoacoustic parameter calculation for one channel, and the master board manages bit allocation, quantization, and bit-stream formatting for all channels. Parallel processing and pipelining techniques are used in hardware structure and fast algorithms are applied in each subroutine to implement a real-time process. The implemented system supports multichannel up to 5.1 and various bitrates.

• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.977-979
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• 1995

MPEG-II is the international standard of compression for digital image and digital audio that is the most important in the multimedia environment. Now many researchers are developing relevant systems. MPEG-II consists of video, audio, system and the other part. In this paper, we have designed and demonstrated two channel audio encoder system that processes the audio compression part, and excutes layer II for complexity and psychoacoustic model II, with ADSP-21020 of Analog Device.

• The Journal of the Acoustical Society of Korea
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• v.28 no.8
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• pp.832-842
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• 2009

Automatic speech recognition (ASR) has been successfully applied to many real human computer interaction (HCI) applications; however, its performance tends to be significantly decreased under noisy environments. The invention of audio visual speech recognition (AVSR) using an acoustic signal and lip motion has recently attracted more attention due to its noise-robustness characteristic. In this paper, we describe our novel integration scheme for AVSR based on a late integration approach. Firstly, we introduce the robust reliability measurement for audio and visual modalities using model based information and signal based information. The model based sources measure the confusability of vocabulary while the signal is used to estimate the noise level. Secondly, the output probabilities of audio and visual speech recognizers are normalized respectively before applying the final integration step using normalized output space and estimated weights. We evaluate the performance of our proposed method via Korean isolated word recognition system. The experimental results demonstrate the effectiveness and feasibility of our proposed system compared to the conventional systems.

• The Journal of the Korea Contents Association
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• v.8 no.6
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• pp.121-129
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• 2008

With the help of information technology The problem of building a concrete form with a shapeless media is the starting point of presenting information by means of sound. Audio-Visual System using sound as a medium is a method that presents an auditory material visually and has a role of linking different sensory organs. In a sense, Audio-Visual System transfers a non-concrete sensation to a concrete one. Audio-Visual System presentation by late methods using active and non-active images produced by computerized irregular procedures can be limited because of the limited ways of visual output. On the other side, visualization using active images can induce more diverse expressions using sound as a medium. This study suggests a new way of expression in animations using visualization of various auditory materials and sounds built by Audio-Visual System with active images.

• Journal of Korean Society of Archives and Records Management
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• v.9 no.1
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• pp.33-50
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• 2009

ADD(Agency for Defense Development) has developed digital audio-visual archives management system to ensure easy access and long-term preservation for digital audio-visual archives. This paper covers total process of the system development and database management in the aspect of preservation and utilization by users' easy search through digitization of audio-visual archives. In detail, it contains system design for images and video data handling, standard workflow establishment, data quality, and metadata settings for database by converting an analog data into digital format. Also, this study emphasizes the importance of audio-visual archives management system through cost-effectiveness analysis.

• Journal of Broadcast Engineering
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• v.17 no.5
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• pp.827-837
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• 2012

As broadcasting environments change rapidly to digital, user requirements for next-generation broadcasting service which surpass current HDTV service become bigger and bigger. The next-generation broadcasting service progress from 2D to 3D, from HD to UHD and from 5.1ch audio to more than 10ch audio for high quality realistic broadcasting service. In this paper, we propose 10.2ch based multichannel audio reproduction system for UHDTV. The 10.2ch-based audio reproduction system add two side loudspeakers to enhance the surround sound localization effect and add two height and one ceiling loudspeakers to enhance the elevation localization effect. To evaluate the proposed system, we used APM(Auditory Process Model) for objective localization test and conducted subjective localization test. As a result of objective/subjective localization test, the proposed system shows the statistically same performance compare with 22.2ch audio system and shows the significantly better performance compared with 5.1ch audio system.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.351-352
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• 2006

The objective criterion is necessary to decide the signal for vehicle audio. In this time, the signals have decided by golden ear or some simple parameters. In this paper, we propose the system for sound quality assessment in the vehicle audio signals. The vehicle audio signals were recorded in many vehicles by same condition. From these signals, objective and subjective parameters were extracted and using these signals listening test was done. The function was estimated between three results by simple neural network system. The score of arbitrary signal can be estimated using the function made by three results. In this way, Sound signal quality is assessed objectively.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1035-1042
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• 2017

In this paper, we implement a public address system using power line communication in order to operate, extend, and expand the complicated public address devices and cables easily. Power line communication based public address system implemented consists of a public address control board and public address speaker boards which are suitable to digital streaming modulation. It can be noticed that we met satisfied results from performance measurement such as maximum audio output, audio channel response time, audio output SNR, and audio output THD+N.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2018.06a
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• pp.158-160
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• 2018

최근 다양한 국제 방송표준에서 차세대 오디오 코덱의 하나로 MPEG-H 3DA(3D Audio)가 채택되었으며, 이를 활용한 몰입형 오디오 서비스들이 개발되고 있다. 이러한 몰입형 서비스를 원활히 제공하기 위해서는 표준에 정의된 기술을 구현한 제품간의 상호호환성 검증이 필수적으로 추진되어야 하며, 이를 위해 개발된 MPEG-H TV Audio System 인증 프로그램에 대해 대상 제품과 시험서비스의 구조에 대해 설명하고 있다.