• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.12
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• pp.1382-1397
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• 1991

The QM-Coder based on the recommandation of the JBIG committee has been studied for applying it to G3 FAX. In the point of view of implementation. the QM-Coder is modified to have following properties : 1) initialized at each start of the new line for protecting the error propagation, 2) pixel context for error estimation, fill bit insertion to meet minimum scan line time of 10 msec. and it is found that the modified QM-Coder is useful for encoding half tone images for low end G3 FAX machine, For higher compression ration than QM-Coder in encoding of the image binarized by ordered orther thchniques, a rearranging process before applying the QM-Coder is used and the resultant compression ratic was increased 1.13∼1.31 times than that of the conventional QM-Coder.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.7
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• pp.831-836
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• 2015

This paper studied scrambling occurrence in the line coder for UTF-8 hangul syllable code based on unicode. The paper suggested that scrambling is occurred when consecutive four "0" bit is entered into the line coder from the source codes. Currently, ITU-T is applying HDB-3 scrambling method in AMI line coder, According to the study result, scrambling is occurred about 39% in UTF-8 code on Unicoe Hangul syllable.

• Journal of Korea Multimedia Society
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• v.10 no.12
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• pp.1551-1558
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• 2007

The standard of evaluating function of speech coder for mobile telecommunication can be shown in channel capacity, noise immunity, encryption, complexity and encoding delay largely. This study is an algorithm to reduce complexity applying to CDMA(Code Division Multiple Access) mobile telecommunication system, which has a benefit of keeping the existing advantage of telecommunication quality and low transmission rate. This paper has an objective to reduce the computing complexity by controlling the frequency band nonuniform during the changing process of LSP(Line Spectrum Pairs) parameters from LPC(Line Predictive Coding) coefficients used for EVRC(Enhanced Variable-Rate Coder, IS-127) speech coders. Its experimental result showed that when comparing the speech coder applied by the proposed algorithm with the existing EVRC speech coder, it's decreased by 45% at average. Also, the values of LSP parameters, Synthetic speech signal and Spectrogram test result were obtained same as the existing method.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.9
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• pp.1019-1026
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• 2015

This paper studied the source coding rule of the characters to minimize the HDB-3 scrambling for UTF-8 code. An existing source coding rule of the characters to minimize the HDB-3 scrambling in the line coder is for the source codes which are directly entered into the line coder without any transformation. Therefore the existing source coding rule can't apply the UTF-8 code which is directly came into an input of line coder. The reason is that the scrambling code in the source codes are not same as UTF-8 codes. So, if they want to analysis the scrambling occurrence situation in UTF-8 codes and make an unscrambling UTF-8 code, they should make a UTF-8 code table for the source codes, find out the scrambling occurrence codes and then encode the unscrambling source code. The source coding rule for UTF-8 code showing this paper can omit such a complicated procedure to encode an unscrambling source code.

• The Journal of the Acoustical Society of Korea
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• v.17 no.3E
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• pp.53-57
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• 1998

Spectral information at a speech coder should be quantized with sufficient accuracy to keep perceptually transparent output speech. Spectral information at a low bit rate speech coder is usually transformed into corresponding line spectrum pair parameters and is often quantized with a vector quantization algorithm. As the vector quantization algorithm generally has high complexity in the optimal code vector searching routine, the complexity reduction in that routine is investigated using the ordering property of the line spectrum pair. When the proposed complexity reduction algorithm is applied to the well-known split vector quantization algorithm, the 46% complexity reduction is achieved in the distortion measure compu-tation.

• Korean Journal of Remote Sensing
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• v.18 no.6
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• pp.359-367
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• 2002

In this paper, a new embedded wavelet packet image coder algorithm is proposed for an effective image coder using correlation between partitioned coefficients. This new algorithm presents parent-child relationship for reducing image reconstruction error using relations between individual frequency sub-bands. By parent-child relationship, every coefficient is partitioned and encoded for the zerotree data structure. It is shown that the proposed wavelet packet image coder algorithm achieves low bit rates and rate-distortion. It also demonstrates higher PSNR under the same bit rate and an improvement in image compression time. The perfect rate control is compared with the conventional method. These results show that the encoding and decoding processes of the proposed coder are simpler and more accurate than the conventional ones for texture images that include many mid and high-frequency elements such as aerial and satellite photograph images. The experimental results imply the possibility that the proposed method can be applied to real-time vision system, on-line image processing and image fusion which require smaller file size and better resolution.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.1
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• pp.39-46
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• 2015

The paper studied possibility of improvement of efficient of data processing in the line coder when Hangul syllables in Unicode system is used for the source code. The scrambling in the line coder is to solve the problem happened due to the source code. The study is based on the HDB-3 scrambling method in ITU-T standards that is applied to AMI line coder. The referred data of Hangul syllables and its use frequency which are required to analysis was used the data extracted from the source data of the National Korean Language Institute. According to the analysis, the average 24% scrambling was generated in source code of Hangul syllables in Unicode system. When the referred Hangul syllables was applied to Unicode system, the average 27% scrambling was producted. Total 8,924ea Hangul syllables in 11,172ea Hangul syllables in Unicode system were not scrambled. Therefore the referred Hangul syllables 1,540ea were accepted in the unscrambled code areas. As a result, the existing Unicode Hangul syllable codes can't prevent the scrambling, but it is possible to completely remove the 27% scrambling with new source coding system. And then, it can be improved the data processing efficient upto minimum 27% in line coder by software in presentation layer instead of physical layer.

• IEIE Transactions on Smart Processing and Computing
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• v.5 no.2
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• pp.143-151
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• 2016

This paper presents new prediction methods to improve compression performance of the so-called near-lossless RGB-domain image coder, which is designed to effectively decrease the memory bandwidth of a system-on-chip (SoC) for image processing. First, variable block size (VBS)-based intra prediction is employed to eliminate spatial redundancy for the green (G) component of an input image on a pixel-line basis. Second, inter-color prediction (ICP) using spectral correlation is performed to predict the R and B components from the previously reconstructed G-component image. Experimental results show that the proposed algorithm improves coding efficiency by up to 30% compared with an existing algorithm for natural images, and improves coding efficiency with low computational cost by about 50% for computer graphics (CG) images.

• Journal of Multimedia Information System
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• v.8 no.4
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• pp.285-294
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• 2021

The development process of domestic CG (Computer Graphics) needs to be studied by classifying the technical part and the design part. This paper analyzes how early domestic broadcast equipment evolved and focused on what went through the development process. Domestic broadcasting companies have introduced and used overseas equipment and have begun to develop their own technology. The development process of the early domestic production technology of broadcasting stations was classified into Character Generator, On-line Real-Time Graphic and Sport Coder. It was found that the orientation of broadcasting technology was conclusively focused on visualization, with socio-cultural factors acting along with the evolution of hardware and software. This research is meaningful in reorganizing the history of the development process of domestic CG technology in the early days through previous research (primary verification), newspaper articles and news coverage (secondary verification). This paper looks at what is missing by regaining the past of CG, and argues that with the advent of new technologies today, we must develop through appropriate division of roles and collaboration between engineers and designers.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.4
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• pp.761-776
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• 2012

This paper proposes the revised Roman character code system using Unicode 3.0. The background of the paper is whether the Latin character code system th using in the world in Unicode V.3 is proper or not in the side of the transmission efficiency in data communications. In data communications, when the consecutive 4 bits or 8 bits of "0" bit from the information devices input into the line coder, its consecutive "0" bits are scrambled to the predetermined bit patterns to avoid the syncronization loss. The paper was based on the statistical data for the using frequency of the alphabet letter and the proposed rule for characters coding in [1]. The paper was focused to improve of Unicode itself and UTF-8 code system. As a result of the paper, when the proposed coding systems for Latin character in Unicode 3.0 itself and UTF-8 code system, the scrambler efficiency using HDB-3 in the line coder of the data transmission system could be improved about 3645 ~ 31400% and 480 ~ 1700% respectively.