• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.07a
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• pp.310-313
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• 2011

Broadcasting nature of wireless communications makes it possible to apply opportunistic network coding (OPNC) by overhearing transmitted packets from a source to sink nodes. However, it is difficult to apply network coding to the topology of multiple relay and sink nodes. We propose to use relay node selection, which finds a proper node for network coding since the OPNC alone in the topology of multiple relays and sink nodes cannot guarantee network coding gain. The proposed system is a novel combination of wireless network coding and relay selection, which is a key contribution of this paper. In this paper, with the consideration of channel state and potential network coding gain, we propose relay node selection techniques, and show performance gain over the conventional OPNC and a channel-based selection algorithm in terms of average system throughput.

• Proceedings of the KIEE Conference
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• 1988.11a
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• pp.477-480
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• 1988

A new image coding system called knowledge- based coding is presented which uses positively the knowledge for coding objects. The 3- dimensional model and the psychological knowledge for a person's face can be used as the knowledge for a coding system, when a person's face is coding object. A transmitter analyzes input images and a receiver synthesizes output images using them. The construction of 3-dimensional model and the introduction of the psychological knowledge to the new coding system are discussed. The basic facial expressions are synthesized from a neutral face using them. The synthesized images are very natural.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.607-610
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• 1998

The major objectives of speech coding include high compression ratio for transmission in the band limited channel, high synthesized speech quality in terms of the intelligibility and the naturalness and fast processing speed. In general, speech coding methods are classified into the following three categories: the wavelform coding, the source coding and the hybird coding. In this paper, we proposed a new waveform coding method using PSOLA(pitch-synchronous overlap add) technique. First, we fixed one basic waveform per pitch and measured the formant similarity between basic and neighbor waveform. Second, if the similairy satisfied threshold values, we compress the neighbor waveform per pitch and then store or transmit. When the comparession is about 45%, we obtained about 4 in MOS.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.5
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• pp.45-55
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• 2010

Object-based audio coding technology has been interested with its expectation to apply in wide areas. Recently, ISO/IEC MPEG has standardized a parametric object audio coding method, the SAOC (Spatial Audio Object Coding). This paper introduces parametric object audio coding techniques with special focus on the MPEG SAOC and also describes several issues and solutions that should be considered for a success in its application.

• Proceedings of the IEEK Conference
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• 2003.11a
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• pp.167-170
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• 2003

We propose stereoscopic video coding method using the syntax of MAC(Multiple auxiliary component) that was added to the MPEC-4 visual version 2 in order to describe the transparency of the video object. We also define the novel MAC's semantics in MPEG-4 that should support the proposed coding method. The major difference between the existing coding method and the proposed coding method is the addition of the residual texture coding. The proposed coding method assigns disparity map and residual texture to 3 components of MAC: one component for disparity map and the rest 2 components fer the luminance and chrominance data of the residual texture, respectively. The performance of the proposed method is evaluated in terms of PSNR by computer simulations.

• ETRI Journal
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• v.39 no.3
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• pp.310-318
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• 2017

Unified speech and audio coding (USAC) is one of the latest coding technologies. It is based on a switchable coding structure, and has demonstrated the highest levels of performance for both speech and music contents. In this paper, we propose an extended version of USAC with a single-mode of operation-which does not require a switching system-by extending the linear prediction-coding mode. The main concept of this extension is the adoption of the advantages of frequency-domain coding schemes, such as windowing and transition control. Subjective test results indicate that the proposed scheme covers speech, music, and mixed streams with adequate levels of performance. The obtained quality levels are comparable with those of USAC.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.12
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• pp.2538-2541
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• 2009

H.264/AVC High 4:4:4 Intra/Predictive profiles supports RGB 4:4:4 sequences for high fidelity video. RGB color planes rather than YCbCr color planes are preferred by high-fidelity video applications such as digital cinema, medical imaging, and UHDTV. Several RGB coding tools have therefore been developed to improve the coding efficiency of RGB video. In this paper, we propose a new method to extract more accurate correlation parameters for inter-plane prediction. We use a searching method to determine the matched macroblock (MB) that has a similar inter-color relation to the current MB. Using this block, we can infer more accurate correlation parameters to predict chroma MB from luma MB. Our proposed inter-plane prediction mode shows an average bits saving of 15.6% and a PSNR increase of 0.99 dB compared with H.264 high4:4:4 intra-profile RGB coding. Furthermore, extensive performance evaluation revealed that our proposed algorithm has better coding efficiency than existing algorithms..

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1998.06b
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• pp.183-188
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• 1998

This paper describes the concept of object-based coding for future broadcasting environments. Digital broadcasting uses the MPEG2 coding scheme which is regarded as a picture-based coding. An object-based coding scheme is a potential candidate for future broadcasting both for studio and distribution uses, and it offers a higher compression more flexible content handling. This paper also describes key technologies that we have been developing for the object-based coding, e.g., image analysis, object extraction and coding of objects.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.608-610
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• 2017

최근 프로그래밍 교육에 대한 요구가 그 어느때보다 높아지고 있다. 특히 프로그래밍교육이 초등학교때부터 의무화되는 2018년을 맞이하여, 수많은 프로그래밍 교육을 위한 연구가 진행되고 있다. 본 논문에서 제안하는 트라이코딩은 게임을 사용하여 학생 스스로가 프로그래밍 및 알고리즘을 학습할 수 있다. 트라이코딩은 기존의 블록기반 및 그림 기반의 프로그래밍 교육을 거친 학생 또는 처음 접하는 학생도 쉽게 게임을 통하여 프로그래밍에 대한 지식을 습득할 수 있게 설계를 하였다. 프로그래밍 언어는 기본적으로 영어를 기반으로 하고 있기 때문에 기초 영어에 대한 이해도가 없이는 이 게임을 진행하기는 힘들어, 추후 게임내에서 사용되는 기초영어 정도는 이 게임에서 학습할 수 있게 하는 시스템이 필요하다.

• Proceedings of the IEEK Conference
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• summer
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• pp.114-117
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• 2004

This paper proposes a novel algorithm for hybrid lossless audio coding, which employs integer discrete cosine transform. The proposed algorithm divides the input signal into frames of a proper length, decorrelates the framed data using the integer DCT and finally entropy-codes the frame data. In particular, the adaptive Golomb-Rice coding method used for the entropy coding selects an optimal option which gives the best compression efficiency. Since the proposed algorithm uses integer operations, it significantly improves the computation speed in comparison with an algorithm using real or floating-point operations. When the coding algorithm is implemented in hardware, the system complexity as well as the power consumption is remarkably reduced. Finally, because each frame is independently coded and is byte-aligned with respect to the frame header, it is convenient to move, search, and edit the coded data.