• Journal of Broadcast Engineering
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• v.11 no.3 s.32
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• pp.363-378
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• 2006

The Digital Multimedia Broadcasting(DMB) system is developed to offer high quality audio-visual multimedia contents to the mobile environment. The system adopts MPEG-4 standard for the main video, audio and other media format. It also adopts the MPEG-4 scene description for interactive multimedia contents. The animated and interactive contents can be actualized by BIFS(Binary Format for Scene), the binary format for scene description that refers to the spatio-temporal specifications and behaviors of the individual objects. As more interactive contents are, the scene description is also needed more high bitrate. However, the bandwidth for allocating meta data such as scene description is restrictive in mobile environment. On one hand, the DMB terminal starts demultiplexing content and decodes individual media by its own decoder. After decoding each media, rendering module presents each media stream according to the scene description. Thus the BIFS stream corresponding to the scene description should be decoded and parsed in advance of presenting media data. With these reason, the transmission delay of BIFS stream causes the delay of whole audio-visual scene presentation although the audio or video streams are encoded in very low bitrate. This paper presents the effective optimization technique for adapting BIFS stream into expected MPEG-2 TS bitrate without any bandwidth waste and avoiding the transmission delay of the initial scene description for interactive DMB contents.

• The Journal of the Acoustical Society of Korea
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• v.22 no.1
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• pp.28-34
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• 2003

Recent researches have been focusing on jointly using lip motions (i.e. visual speech) and speech for reliable speech recognitions in noisy environments. This paper also deals with the method of combining the result of the visual speech recognizer and that of the conventional speech recognizer through putting weights on each result: the paper proposes the method of determining proper weights for each result and, in particular, the weights are autonomously determined, depending on the amounts of noise in the speech and the image quality. Simulation results show that combining the audio and visual recognition by the proposed method provides the recognition performance of 84% even in severely noisy environments. It is also shown that in the presence of blur in images, the newly proposed weighting method, which takes the blur into account as well, yields better performance than the other methods.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.769-773
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• 2009

본 연구는 MRI 검사를 받은 환자를 대상으로 영상매체(Visual equipment & Audio system)를 이용하여 영상물을 제공함으로서 불안과 불편감에 대한 효과에 대해 규명함으로써 MRI 검사로 인한 심리적, 정신적 불안과 불편 감을 감소시킬 수 있는 대체요법을 제공하기 위하여 본 연구를 시도하였다. 연구대상은 대전광역시에 위치한 K 대학병원에서 MRI 검사를 받은 환자 중 영상물을 제공받은 실험군 30명과 영상물을 제공받지 않은 대조군 30명을 대상하였다. 연구의 도구는 Spielberger의 기질불안 도구와 Cline, Herman, Shaw와 Morton이 고안한 불안점수 도구인 시각적 상사척도(VAS)를 이용하였고, 영상물을 제공하여 두 군 간의 활력징후를 측정하였고 불편감은 대상자의 주관적 불편감(어지러움, 공포감. 긴장감)점수와 객관적 불편감 행동 점수를 사용하였다. 자료 분석 방법은 SPSS12K for Windows program을 이용하였으며, 두 군의 일반적 특성 및 수술에 관련된 특성의 동질성 검증은 $\chi^2$ 검정, 가설검증은 t-test로 분석하였다. 연구결과를 요약해 보면 영상매체(Visual equipment & Audio system)를 이용하여 영상물(영화, 애니메이션)을 제공하면서 MRI 검사를 진행했을 경우 검사 대상자의 혈압 및 객관적 불편감에서는 유의한 영향을 미치지 못했으나 불안과 활력징후의 하나인 맥박의 감소, 또한 주관적 불편감이 감소됨을 알 수 있었다. 따라서 환자의 심리적인 긴장감을 완화시키며 안정감을 느끼게 하는데 효과적인 대체요법이 될 수 있을 것으로 사료 된다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.7
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• pp.1488-1492
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• 2004

The digital signal has been replaced the analog signal in most of every field of multimedia including still image, animation, and audio due to the enormous extension of computer supply and the fast development of computer network. The consumers of information are able to enjoy the abundance of information because of one of the digital signal traits that very easy to regenerate the original data. Because of the trait, however, it is very hard for the producers of information to keep the copyright with the merit of original copy in quality excellency. In this paper, the watermarking technology which inserts a RGB color watermark in color image using the visual characteristics of wavelet coefficient was proposed. As a result, the PSNR value of image was varied depending on perceptual parameter, but we can obtain 32dB as a whole.

• Journal of KIISE:Software and Applications
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• v.27 no.8
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• pp.864-876
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• 2000

This paper proposes a new scene boundary detection scheme for the MPEG System stream using MPEG Audio information and proves its usefulness by extensive experiments. A scene boundary has a characteristic that the audio as well as video information are changed rapidly. This paper first classifies this scene boundary into three cases ; Radical, Gradual, Micro Changes, with respect to the audio changes. The Radical change has a large-scale changing of decibel value and pitch value at a scene boundary, the Gradual change shows the long-time transition of decibel and pitch values from max to min or vice versa, and the Micro change displays a some change of pitch or frequency distribution without decibel changes. Upon this analysis, a new scene change detection algorithm detecting these three cases is proposed in which a progressive window with a time line is used to trace the changes in the audio information. Some experiments with various movies show that proposed algorithm could produce a high detection ratio for Radical change that is the most popular scene change in the movies, while producing a moderate detection ratio for Gradual and Micro changes. The proposed scene boundary detection scheme could be used to build a database for visual information like MPEG System stream.

• Journal of the Korea Society of Computer and Information
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• v.14 no.2
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• pp.181-190
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• 2009

This paper presents a multimodal emergency recognition system based on visual information, audio information and gravity sensor information. It consists of video processing module, audio processing module, gravity sensor processing module and multimodal integration module. The video processing module and gravity sensor processing module respectively detects actions such as moving, stopping and fainting and transfer them to the multimodal integration module. The multimodal integration module detects emergency by fusing the transferred information and verifies it by asking a question and recognizing the answer via audio channel. The experiment results show that the recognition rate of video processing module only is 91.5% and that of gravity sensor processing module only is 94%, but when both information are combined the recognition result becomes 100%.

• The Transactions of the Korea Information Processing Society
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• v.5 no.8
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• pp.1960-1971
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• 1998

The researches and developments to provide multimedia communication services such as Video on Demand(VoDJ), real time video phonc and multipoint vidco conferencing on broadband ISDN environmcnts have been proceeded with activity. Specifications for Vol) services which is worked by Digital Audio-Visual Council(DAVIC) to support detail technologies including total service system that is consist of VoD server. delive[\! networl, and Set-Top Box(STB) had been already finished and ITU-T SG16 also recommended the standards of H.300 series terminal aspects for conversational multimedia services, But the architectures of multimedia tenninals recommended and specified by these organizations do not have an efficient st11lcture to provide all of retrieval, distrihution and conversational service due to a different point of view about multimedia terminals and services. In this paper, we analyzed the recornmendatio!E and the specifications of intemational public and private organizations like lTU-T, DAVIC and ATM forum. As a result of these analysis. we propose an efficient terminal architecture, and then we have designed, lmplemented the multimedia communication terminal for offering VoI) and real- time conversation ,,, functional module test according to the individual commumication service session and confirined the validiry or terminal implemented to be used on broadband ISDK environments.

• 대한공업교육학회지
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• v.30 no.1
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• pp.120-132
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• 2005

The major purpose of this study was to provide a basic model of mobile guide system for visitor's individual learning, self-regulated learning in a museum. System model realized by this study was as follows; 1) This system distributed exhibit information to tourists in place of existing audio guides or curators. Using wireless communications, the PDA automatically delivered information about the exhibit. The artistic and visual displays maximized effective and quick transmission of information to the user. 2) It made visiting a museum fun, exciting and entertaining. With the PDA guide the museum visitor can interact with detailed descriptions of exhibits, videos and images. The museum visitor, can also play a quiz game, take photos, record voices and send e-mail.

• ETRI Journal
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• v.26 no.2
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• pp.149-160
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• 2004

In this paper, we present an interactive data broadcasting system compliant with the Advanced Television Systems Committee (ATSC) standards. The proposed system provides users not only with various data broadcasting services but also remote interactive services. For various data broadcasting services, we have adopted a synchronized data injector that calculates the transmission time of synchronized data accurately and multiplexes synchronized data with the data of an MPEG-2 audio-visual program according to the calculated transmission time. To support remote interactive services, we designed and implemented a return channel server connected on a bi-directional interaction channel. Test results show that the proposed system provides both an asynchronous and synchronized data broadcasting service and remote interactive service appropriately.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.6B
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• pp.1060-1067
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• 2000

MPEG-4 visual coding is an object-based system. The current video coding standards, H.261, MPEG-1, and MPEG-2 encode frame by frame. On the other hand, MPEG-4 separately encodes several objects, such as video objects and audio objects, in the same frame. Each transmitted object is decoded and composed in one frame. Shape coding is a process of coding visual objects in a frame. In this paper we present conformance test method for MPEG-4 shape decoders. This paper reviews the basic shape decoding standard, and proposes conformance test methods for BAB type decoder, and CAE decoder for intra and inter VOPs. Our test generates all possible cases of shape motion vector difference and context.