• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(3)
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• pp.235-238
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• 2002

This paper presents a remote mobile robot system that transmits streaming video and audio over the lossy packet networks such as (Wireless) LAN. The error resilient video and audio packets are transmitted on the RTP/UDPfP Protocol stack. The mobile robot can be accessed by a certified user from the remoted area. Thus, the movement of mobile robot can be controlled by the operator observing the working surroundings.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(5)
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• pp.55-58
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• 2002

This paper describes an RF module for 2.4GHz wireless audio/video transmission. The pre-processed baseband input signals are FM-modulated using a VCO and then transmitted through an antenna after RF filtering. The designed circuits are implemented using a Teflon board of which the size is 52mm${\times}$62mm. The measured maximum output signal levels are around -3dBm and the harmonics are less than -450dBc. The manufactured module consumes 130mA from a 8V supply.

• 전기학회논문지
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• 제62권12호
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• pp.1764-1770
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• 2013

Use of the 5.1 channel audio signals suitable for the television system is improper for the radio broadcasting system, which uses the stereo audio system. Therefore, it is necessary to develop an audio down-mixer to convert 5.1 multi-channel audio signals to stereo signals for radio broadcasting. In this paper, a development of an audio down-mixer was carried out to convert 5.1 multi-channel audio signals to stereo signals. The down-mixer which was developed can use the audio signals separated from video signals, including sound signals or individual signals provided from 3-channel AES/EBU signals including Left(L), Right(R), Left Surround(Ls), Right Surround(Rs), Center(C) and Low Frequency Effect(Lfe) sounds as mixer inputs.

• Journal of information and communication convergence engineering
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• 제18권2호
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• pp.115-122
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• 2020

Audiovisual (AV) facilities such as TVs and signage are installed in various public places. However, audio cannot be used to prevent noise and interference from individuals, which results in a loss of concentration and understanding of AV content. To address this problem, a total technique for remotely listening to audio from audiovisual facilities with clean sound quality while maintaining video and lip-syncing through personal smart mobile devices is proposed in this paper. Through the experimental results, the proposed scheme has been verified to reduce system power consumption by 8% to 16% and provide real-time processing with a low latency of 120 ms. The system described in this paper will contribute to the activation of audio telehearing services as it is possible to provide audio remote services in various places, such as express buses, trains, wide-area and intercity buses, public waiting rooms, and various application services.

• 영어어문교육
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• 제11권2호
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• pp.135-148
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• 2005

This paper investigated the effect of audio and visual cues on Korean and Japanese EFL learners' perception of the lateral/retroflex contrast in English. In a perception experiment, the two English consonants /l/ and /r/ were embedded in initial and medial position in nonsense words in the context of the vowels /i, a, u/. Singletons and clusters were included in the speech material. Audio and video recordings were made using a total of 108 items. The items were presented to Korean and Japanese learners of English in three conditions: audio-alone (A), visual-alone (V) and audio-visual presentation (AV). The results showed that there was no evidence of AV benefit for the perception of the /l/-/r/ contrast for either Korean or Japanese learners of English. Korean listeners showed much better identification rates of the /l/-/r/ contrast than Japanese listeners when presented in audio or audio-visual conditions.

• 한국컴퓨터산업학회논문지
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• 제3권3호
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• pp.283-294
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• 2002

인터넷이 상용화된 요즈음, 웹을 기반으로 한 동영상 e-mail 시스템이 본격적으로 필요한 시기이다. 그러나 비디오 데이터는 너무 용량이 커서 상당한 압축을 하지 않는다면 인터넷 상에서의 전송이 매우 어렵다. 본 연구에서는 국제 표준으로 자리잡은 MPEG-4 기술을 이용하여 동영상 메일을 구현하면서, 기존의 방법으로는 해결하기 힘든 동영상의 실시간 압축, 웹 상에서의 자유로운 접근을 가능하게 하는 액티브 엑스 제어(Active X Control) 기술 등을 동영상 및 오디오 압축 기술과 함께 개발하여 적용하였다. 이 기술을 이용하면 누구나 자유롭게 동영상 메일을 전세계 어디로나 보내는 것이 가능하다. 한편 이 기술의 주요한 응용분야는 멀티미디어 메일링 서비스, 동영상 광고, 원격 교육 및 진료, 쇼핑 물 구축 등이다.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1994년도 FIFTH WESTERN PACIFIC REGIONAL ACOUSTICS CONFERENCE SEOUL KOREA
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• pp.912-918
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• 1994

Poor speech intelligibility in an air traffic control room is frequently a result of many, quite different causes and occasionally leads to complaints of the controller personnel. The paper describes a sequence of successful tasks performed in a local control room. The initial measurements included an investigation of the background noise (caused by fans, air condition, computer and radar equipment) and performance checks of the electronic audio and communication equipment with respect to the audio transmission behavior. The spectral composition of the noise as well as the characteristics of the audio communication path between the controllers and the pilots(which showed a loss of spectral information in the audio band due to built-in notch filters for the suppression of control tones) required adaptations of the amplitude behavior of the amplifiers through user adjustable tone controls. The radar console fans, which contributed significantly to the overall noise floor of the room, underwent a substantial reconstruction by replacing the tight mounting with an elastic double suspension, reducing the noise level by 50%. Finally, a possible source of untimely fatigue of the controllers during their working hours has been found in strong spectral components of the noise above the audio band, radiated by numerous video monitors in the control through vibrating components excited by the line frequency of the video signal.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2007년도 추계종합학술대회
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• pp.615-618
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• 2007

영상압축 기술의 발달과 디지털 방송을 위한 표준 확립으로 아날로그 영상의 디지털 표현과 방송이 가능하게 되었다. 현재 디지털 방송서비스를 제공하는 종합유선방송사업자들(SO : System Operator)은 고객의 기호에 맞는 방송 콘텐츠를 제공하고 있을 뿐 아니라 독자적인 방송편성을 통해 자체 제작한 방송 콘텐츠를 제공하고 있다. 자체 제작된 방송 콘텐츠의 제공을 위해서는 방송 정보의 생성과 방송 영상 데이터와의 재다중화가 필요하며 이는 현재 고가의 장비에서만 지원되고 있어 원활한 디지털 방송 콘텐츠의 제작에 어려움이 있다. 이에 본 논문에서는 디지털 방송 콘텐츠 제작 시 방송 정보를 사용자로부터 입력받아 PSIP (Program and Service Information Protocol) 정보를 생성하고 생성된 방송 영상 데이터에 PSIP 정보를 직접적으로 맵핑하는 PSIP 정보 생성 시스템을 설계 및 구현하였다.

• 인터넷정보학회논문지
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• 제16권2호
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• pp.1-6
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• 2015

본 논문에서는 고품질 멀티미디어 데이터를 IEEE 802.1 Audio Video Bridging 기반의 네트워크를 통해 스마트 자동차와 스마트 홈 및 스마트 공연장에서 실시간으로 송수신할 수 있는 임베디드 플랫폼을 설계를 통해 정밀한 시간 동기화 표준인 IEEE 802.1AS와 QoS 보장을 위한 자원할당 표준인 IEEE 802.1Qat 프로토콜 분석을 통해 성능을 검증한다. 이를 위해 MRP(Multiple Registration Protocol), MMAP(Multicast Address Acquisition Protocol), IEEE 1722, 1722.1 등 AVB의 핵심 Layer-2 프로토콜을 리눅스 운영체제를 기반으로 구현한다. 아울러 상용 AVB 엔드포인트와 연동 실험을 통해 상호 호환성 및 멀티미디어 스트림의 실시간 송수신이 가능함을 보인다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제13권3호
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• pp.164-170
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• 2013

Recent years have been higher demands for automatic speech recognition (ASR) systems that are able to operate robustly in an acoustically noisy environment. This paper proposes an improved product hidden markov model (HMM) used for bimodal speech recognition. A two-dimensional training model is built based on dependently trained audio-HMM and visual-HMM, reflecting the asynchronous characteristics of the audio and video streams. A weight coefficient is introduced to adjust the weight of the video and audio streams automatically according to differences in the noise environment. Experimental results show that compared with other bimodal speech recognition approaches, this approach obtains better speech recognition performance.