• The Journal of the Acoustical Society of Korea
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• v.28 no.7
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• pp.589-598
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• 2009

As mobile devices become multi-functional, and converge into a single platform, there is a strong need for a codec that is able to provide consistent quality for speech and music content MPEG-D USAC standardization activities started at the 82nd MPEG meeting with a CfP and approved WD3 at the 88th MPEG meeting. MPEG-D USAC is converged technology of AMR-WB+ and HE-AAC V2. Specifically, USAC utilizes three core codecs (AAC ACELP and TCX) for low frequency regions, SBR for high frequency regions and the MPEG Surround tool for stereo information. USAC can provide consistent sound quality for both speech and music content and can be applied to various applications such as multi-media download to mobile device Digital radio Mobile TV and audio books.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.787-789
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• 2001

본 논문에서는 소프트웨어 기반의 실시간 MPEG겨 비디오 부호화기를 제안하였다. MPEG 에서 제공하는 MPEG-4 참조 소프트웨어 비디오 부호화기는 여러 가지 기능이 혼합되어 있는 복잡한 구조를 가지고 있기 때문에 실시간으로 부호화하는 데 많은 어려움이 있다. 이를 PC에서 실시간으로 부호화할 수 있도록 목표를 심플 프로파일로 제한하여 이에 맞도록 구조를 수정하고, 고속 움직임 벡터 예측 알고리즘을 사용하여 움직임 예측시의 계산량을 줄였으며, 실시간으로 부호화할 시에 많은 부하를 주는 부분인 DCT, 움직임 예측 및 보상, 보간 부분을 MMX(MultiMedia Extention) 방법으로 구현하여 계산량과 부하를 줄임으로써 보다 향상된 성능을 제공한다. 기존 부호화기의 부호화 시의 복잡성을 감소시키고 윈도우 환경에서 간단한 조작만으로 부호화를 할 수 있도록 하였다.

• The Journal of the Acoustical Society of Korea
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• v.28 no.7
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• pp.618-629
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• 2009

The MPEG-4 Audio Lossless Coding (ALS) standard belongs to the family MPEG-4 audio coding standards. In contrast to lossy codecs such as AAC, which merely strive to preserve the subjective audio quality, lossless coding preserves every single bit of the original audio data. The ALS core codec is based on forward-adaptive linear prediction, which combines remarkable compression with low complexity. Additional features include long-term prediction, multichannel coding, and compression of floating-point audio material. This paper describes the basic elements of the ALS codec with a focus on prediction, entropy coding, and related tools and points out the most important applications of this standardized lossless audio format.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.3C
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• pp.240-246
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• 2008

An MPEG-2/4 AAC decoder on 16-bit fixed-point processor is presented in this paper. To meet audio quality criteria, despite small word length, special design methods for 16-bit foxed-point AAC decoder were devised. This paper presents particular algorithms for 16-bit AAC decoding. We have implemented an efficient AAC decoder using the proposed algorithms. Audio contents can be replayed in the decoder without quality degradation.

• Information and Communications Magazine
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• v.31 no.4
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• pp.70-78
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• 2014

MMT (MPEG Media Transport) 기술은 지난 4년여 기간 동안 ISO MPEG의 표준화 과정을 거치면서 현재 FDIS (Final Draft for International Standard) 수준까지 도달하였고, 2014년 3월 스페인 발렌시아에서 개최될 제 108차 MPEG 회의에서 국가 투표 (national ballot)를 거쳐 IS (International Standard)로 승인될 예정이다. 본 고에서는 MMT 기술의 표준화 현황과 세부 기술 사항에 대해 분석한다. 또한, 하이브리드 미디어 전송을 지원하기 위한 MMT 표준기술의 기술적 사양에 대해 설명한다.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.5
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• pp.25-33
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• 2010

Multi-media service has been changed into user based audio services, which service supports actively user's preference and interaction with the users. In the market, multi-media products which can support the highest audio-quality by using lossless audio technology have been released and object audio music which user can select the objects has been serviced. In this paper, we design user's preference information based object audio file format and audio scene description for storage and transmission media. The designed file format is designed based on MPEG-4 file format because high-quality audio codecs in MPEG-4 audio can be easily used and the track of file format can be flexibly controlled depend on the number of the instrument in music. The encoded audio data of each objects and encoded audio scene description by binary encoding that has independent track are packed in a file. The scene description for storage media is consist of full and object scene description, the scene description for transmission media has an essential description for object audio operation and a specific description for real audio sound. The designed file format based simulator is developed and it generates an object audio file with several scene descriptions. Also, the real audio sound is serviced by the interaction with user and the unpacked scene description.

• Polymer(Korea)
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• v.28 no.4
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• pp.328-334
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• 2004

A series of methoxy poly(ethylene glycol) (MPEG)-poly(L-lactide-co-glycolide) (PLGA) diblock copolymers were synthesized by ring-opening polymerization of L-lactide and glycolide with carbitol (134 g/mole) or different molecular weights of MPEG (550, 2000, and 5000 g/mole) as an initiator in presence of Sn(Oct)$_2$. The properties of diblock copolymers were characterized by using $^1$H-NMR, GPC, and XRD. After uniform mixing of block copolymers and 1% albumin bovine-fluorescein isothiocyanate(FITC-BSA) with a freeze miller, the wafers loaded FITC-BSA were fabricated by using a mold with a dimensions of 3 mm${\times}$1mm diameter. The release profiles of FITC-BSA and the pH changes of wafer were examined using pH 7.4 PBS for 30 days at 37$^{\circ}C$. The release profiles of albumin showed fast initial burst as the molecular weights of MPEG increased. As a result of this study, the release behavior of BSA was controlled with introducing MPEG in the block copolymers.

• Journal of Broadcast Engineering
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• v.24 no.4
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• pp.660-669
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• 2019

Recently, with the development of three-dimensional scanning devices and multi-dimensional array cameras, research is continuously conducted on techniques for handling three-dimensional data in application fields such as AR (Augmented Reality) / VR (Virtual Reality) and autonomous traveling. In particular, in the AR / VR field, content that expresses 3D video as point data has appeared, but this requires a larger amount of data than conventional 2D images. Therefore, in order to serve 3D point cloud content to users, various technological developments such as highly efficient encoding / decoding and storage, transfer, etc. are required. In this paper, V-PCC bit stream created using V-PCC encoder proposed in MPEG-I (MPEG-Immersive) V-PCC (Video based Point Cloud Compression) group, It is defined by the MPEG-DASH (Dynamic Adaptive Streaming over HTTP) standard, and provides to be composed of segments. Also, in order to provide the user with the information of the 3D coordinate system, the depth information parameter of the signaling message is additionally defined. Then, we design a verification platform to verify the technology proposed in this paper, and confirm it in terms of the algorithm of the proposed technology.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04a
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• pp.183-186
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• 2002

MPEG-4는 기존의 MPEG-1, MPEG-2와 달리 멀티미디어를 위한 객체 기반의 부호화에 관한 표준이다. MPEG-4의 장면은 여러 개의 객체로 이루어져 있기 때문에 각 객체들을 시간, 공간적으로 표현하기 위한 장면 기술의 방법으로 BIFS(Binary Format for Scene description)를 규정하고 있다. MPEG-4 단말기에서는 부호화된 BIFS 정보를 복호화하여 각 객체들을 화면에 구성하게 되며, 객체의 특성, 행동들을 정의하거나 변경할 수 있고 새로운 객체들을 포함하는 등의 사용자 상호 작용에 따른 기능을 수행하게 된다. 그러나, 사용자 상호 작용에 따른 장면 재구성은 초기 장면을 구성할 때 기술된 장면 정보를 벗어날 수 없는 제약을 받게 된다. 따라서 본 논문에서는 BIFS 수정 정보 발생기 (BIFS modifier)를 가진 시스템 구조를 제안한다. 제안된 시스템 구조에서 BIFS 수정 발생기는 사용자의 상호 작용이 발생한 노드를 전달 받아 이에 상응하는 BIFS 정보를 기존의 BIFS 정보에서 찾은 후 이를 수정하여 BIFS 변경(BIFS update) 명령을 만들어내고 이에 따라 장면을 재구성하여 동적인 장면 구성을 가능하게 한다. 또한, 제안된 시스템 구조를 주요 응용 분야인 peer-to-peer(P2P)를 가정한 네트웍 기반의 게임에 직접 적용하여 보았다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.1 no.3
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• pp.91-96
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• 2008

An image scalablity function is noted as technology to embody One Source-Multi-use's Image division by the network Bandwidth and diversification of resolution of reception terminal recently. In MPEG present H.264/MPEG-4 AVC that do to standardization of SVC (Scalable Video Coding) that know go and SVC can offer space time SNR scalability. But, encoding that do scalable usually is known that encoding efficiency drops than encoding that do rain scalable during time and treatise that see. Examine technique to plan improvement of management quality as that aim to time, SNR scalability in treatise that see so and change FGS (Fine Granular Scalability) function that offer SNR scalability that do about scalability's particle size and encoding efficiency relation by SVC to foundation.