• Title/Summary/Keyword: Bit Stream

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Design of Low Cost H.264/AVC Entropy Coding Unit Using Code Table Pattern Analysis (코드 테이블 패턴 분석을 통한 저비용 H.264/AVC 엔트로피 코딩 유닛 설계)

  • Song, Sehyun;Kim, Kichul
    • Journal of IKEEE
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    • v.17 no.3
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    • pp.352-359
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    • 2013
  • This paper proposes an entropy coding unit for H.264/AVC baseline profile. Entropy coding requires code tables for macroblock encoding. There are patterns in codewords of each code tables. In this paper, the patterns between codewords are analyzed to reduce the hardware cost. The entropy coding unit consists of Exp-Golomb unit and CAVLC unit. The Exp-Golomb unit can process five code types in a single unit. It can perform Exp-Golomb processing using only two adders. While typical CAVLC units use various code tables which require large amounts of resources, the sizes of the tables are reduced to about 40% or less of typical CAVLC units using relationships between table elements in the proposed CAVLC unit. After the Exp-Golomb unit and the CAVLC unit generate code values, the entropy unit uses a small size shifter for bit-stream generation while typical methods are barrel shifters.

A Study on Effective Bandwidth Algorithms for Mass Broadcasting Service with Channel Bonding (채널 결합 기반 대용량 방송서비스를 위한 유효 대역폭 추정 알고리즘에 대한 연구)

  • Yong, Ki-Tak;Shin, Hyun-Chul;Lee, Dong-Yul;You, Woong-Sik;Choi, Dong-Joon;Lee, Chae-Woo
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.49 no.3
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    • pp.47-61
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    • 2012
  • parallel transmitting system with channel bonding method have been proposed to transmit mass content such as UHD(Ultra High Definition) in HFC(Hybrid Fiber Coaxial) networks. However, this system may lead to channel resource problem because the system needs many channels to transmit mass content. In this paper, we analyze three effective bandwidth approximation algorithms to use the bonding channel efficiently. These algorithms are the effective bandwidth of Gaussian approximation method algorithm proposed by Guerin, the effective bandwidth based on statistics of video frames proposed by Lee and the effective bandwidth based on Gaussian traffic proposed by Nagarajan. We also evaluate compatibility of algorithms to the mass broadcasting service. OPNET simulator is used to evaluate the performance of the algorithms. For accuracy of simulation, we make mass source from real HD broadcasting stream.

A High Speed MUX/DEMUX Chip using ECL Macrocell Array (ECL 매크로 셀로 설계한 고속 MUX/DEMUX 소자)

  • Lee, Sang-Hun;Kim, Seong-Jin
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.39 no.6
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    • pp.51-58
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    • 2002
  • In this paper, a 155/311 Mb/s MUX/DEMUX chip using ECL macrocell away has been developed with a single device. This device for a 2.5 Gb/s SDH based transmission system is to interleave the parallel data of 51 Mb/s into 155 Mb/s(or 311 Mb/s) serial data output, and is to interleave a serial input bit stream of 155 Mb/s(or 311 Mb/s) into the parallel output of 51 Mb/s. The input and output of the device ate TTL compatible at the low-speed end, but 100k ECL compatible at the high-speed end. The device has been fabricated with Motorola ETL3200 macrocell away The fabricated chip shows the typical phase margin of 180 degrees and output data skew less than 220ps at the high-speed end.

Error Recovery by the Classification of Candidate Motion Vectors for H.263 Video Communications (후보벡터 분류에 의한 영상 에러 복원)

  • Son, Nam-Rye;Lee, Guee-Sang
    • The KIPS Transactions:PartB
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    • v.10B no.2
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    • pp.163-168
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    • 2003
  • In transmitting compressed video bit-stream over Internet, packet loss causes error propagation in both spatial and temporal domain, which in turn leads to severe degradation in image quality. In this paper, a new approach for the recovery of lost or erroneous Motion Vector(MV)s by classifying the movements of neighboring blocks by their homogeneity is proposed. MVs of neighboring blocks are classified according to the direction of MVs and a representative value for each class is determined to obtain the candidate MV set. By computing the distortion of the candidates, a MV with the minimum distortion is selected. Experimental results show that the proposed algorithm exhibits better performance in many cases than existing methods.

Recovering Corrupted Motion Vectors using Discontinuity Features of an Image (영상의 불연속 특성을 이용한 손상된 움직임 벡터 복원 기법)

  • 손남례;이귀상
    • Journal of KIISE:Information Networking
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    • v.31 no.3
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    • pp.298-304
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    • 2004
  • In transmitting a compressed video bit-stream over Internet, a packet loss causes an error propagation in both spatial and temporal domain, which in turn leads to a severe degradation in image quality. In this paper, a new error concealment algorithm is proposed to repair damaged portions of the video frames in the receiver. Conventional BMA(Boundary Matching Algorithm) assumes that the pixels on the boundary of the missing block and its neighboring blocks are very similar, but has no consideration of edges t)r discontinuity across the boundary. In our approach, the edges are detected across the boundary of the lost or erroneous block. Once the edges are detected and the orientation of each edge is found, only the pixel difference along the expected edges across the boundary is measured instead of calculating differences between all adjacent pixels on the boundary. Therefore, the proposed approach needs very few computations and the experiment shows an improvement of the performance over the conventional BMA in terms of both subjective and objective quality of video sequences.

An Improved Reconstruction Algorithm of Convolutional Codes Based on Channel Error Rate Estimation (채널 오류율 추정에 기반을 둔 길쌈부호의 개선된 재구성 알고리즘)

  • Seong, Jinwoo;Chung, Habong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.42 no.5
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    • pp.951-958
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    • 2017
  • In an attack context, the adversary wants to retrieve the message from the intercepted noisy bit stream without any prior knowledge of the channel codes used. The process of finding out the code parameters such as code length, dimension, and generator, for this purpose, is called the blind recognition of channel codes or the reconstruction of channel codes. In this paper, we suggest an improved algorithm of the blind recovery of rate k/n convolutional encoders in a noisy environment. The suggested algorithm improves the existing algorithm by Marazin, et. al. by evaluating the threshold value through the estimation of the channel error probability of the BSC. By applying the soft decision method by Shaojing, et. al., we considerably enhance the success rate of the channel reconstruction.

Development of a Portable Digital Electrocardiograph(ECG) measurable with Gel-less Metal Electrodes (젤리스 금속 전극으로 측정가능한 휴대용 디지털 심전도계의 개발)

  • Nam, Young-Jin;Park, Kwang-Min
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.4
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    • pp.1903-1907
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    • 2013
  • Heart condition should be observed for long periods of time because it does not appear abnormal all the time. However, there are many difficulties checking our health for a long time due to its size, operation of equipment, and cost. To solve these problems, an electrocardiograms(ECG), specially interfacing three gel-less metal electrodes for low cost portable applications, is designed and implemented. Gel-less metal electrodes are used for ECG monitoring system instead of gel-type electrodes that can cause skin rashes and itching problem. The whole ECG system consists of two parts-analog and digital circuits. The analog measurement circuit that has a 18*25mm size is made up of op-amps maintaining a sufficiently high common-mode noise rejection and passive elements of SMD type. Analog heart signal is converted to digital stream suitable for display on a TFT-LCD by an 8-bit microcontroller. The size of the completed ECG system is 25*80*50mm and its weighing is about 150g, which is small enough to be easily used. Therefore, the implemented ECG system can be used as a portable one.

Effective Transmission System of Multimedia Services using Eureka-147 DAB (Eureka-147 DAB를 통한 멀티미디어 서비스의 효율적인 전송시스템)

  • Na, Nam-Woong;Baek, Sun-Hye;Hong, Sung-Hoon;Lee, Hyun;Lee, Bong-Ho;Lee, Soo-In
    • Journal of Broadcast Engineering
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    • v.8 no.1
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    • pp.72-79
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    • 2003
  • The Eureka-147 Digital Audio Broadcasting(DAB) system is the new international standard for mobile broadcasting services including high-quality audio, program associated data and other multimedia data. In this paper, we design the transport frame structures for the mobile multimedia services by using the configuration of the Eureka-147 DAB multiplex and MPEG system specifications, and then compare their performances in terms of functionality and overhead. Especially, we suggest and analyze the effective transport structures, which are improved in the efficiency of media multiplexing architecture, by removing the functionally overlapped parts between DAB and MPEG systems. In addition, we evaluate the transmission environments of various DAB data channels and demonstrate the transmission error effects on the low bit rate video stream.

On the error rate of multicode-CDMA system in frequency selective fading channel (주파수 선택적 페이딩 채널에서 멀티코드 CDMA 시스템의 성능 분석)

  • 김연진;김남수;김민택
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.23 no.4
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    • pp.932-939
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    • 1998
  • In this paper, we analyze the performance of a multicode-CDMA system which have been proposed for the multimedia communications. The performance of a multicode-CDMA system, providing good spectrum efficiency as well as serving various bit rates, is analyzed with multipath, frequency selective, slowly fading Rayleigh channel. Also the proposed scheme adopting RAKE receiver with MRC(Maximal Ratio Combine) is advantageous to multipath channel. For a practical channel modeling, the JTC(Joint Technical Committee) recommended channel model(JTC(AIR) 23-065R6) is applied to simulation. The proposed schemehas serial-to-parallel convertor which splits input data stream of 2 Mits/s into 20 branches o 100 kbits/s. From the result of simulation, the case of RAKE receiver with 3 fingers to reduce the system complexity required the relatively large $E_{b}/N_O$ of 0 dB~1.5 dB, compared to the case of RAKE receiver with the number of path finger to keep the average error rate to be $1{\times}10^{-3}$ in channel A.

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The Origin and Development of Korean Names (우리 성명(姓名)의 생성 발달에 대하여)

  • 도수희
    • Lingua Humanitatis
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    • v.1 no.1
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    • pp.255-274
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    • 2001
  • This paper examines the history of Korean names, focusing on the structural characteristics and the literal meanings of those for kings and ordinary people. Roughly speaking, the Korean surname system traces its source to China. Historical records show that the Chinese were already using their family names around 1000 B.C. After a millennium or so, the Korean began to follow suit. Initially, however, surnames were in regular use among kings and their kin only: it was not until the late Shilla dynasty, around A.D. 800, that the commoners began to have Heir surnames. And yet, surnames still tended to be limited to men of noble birth, until around A.D. 1000. Though the Korean surname system may be said to have its origin in Chinese, there are no lack of native surnames that have as long a history, e.g., Hae, Bak, Sok, Sol, Ul, and Ol. Typical surnames of Chinese origin that are found during the late Shilla dynasty, around A.D. 900, include Jang (as in Jang Bogo) and Choi (as in Choi Chiwon). Unlike those of Chinese origin, typical Korean names during the age of Three Nations tended to allude to nature or natural phenomena, as can be witnessed in Bit 'light,' Balgum 'bright,' Nuri 'world,' and Soidori where soi means 'steel' and dol 'stone,' Other surnames abound that have to do with river, stream, field, prairie, and so on. King Muryong's original name was Sama, a variant of som 'island,' indicating where he was born. A person skilled in archery was called Jumong or Hwalbo. Baembo was so called because he 'crawls like a snake, baem,' In these last two examples, bo, as well as its variant bu, functions as a suffix, and is also found in Cochilbu, Isabu, Babo, Nolbu, Hungbu, etc. The tradition of using this kind of native Korean names has gradually disappeared, giving place to the names of Chinese style-although very recently we see an on-going movement toward using native names.

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