• Journal of Broadcast Engineering
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• v.21 no.3
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• pp.341-348
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• 2016

HEVC is the next compression standard and is expected to be used widely replacing the conventional H.264/AVC standard. The compression ratio of the HEVC is twice times than H.264/AVC, whereas its computational complexity is increased by up to 40%. Many research efforts have been made to reduce the computational complexity and to speed up encoding. For intra coding, the rough mode decision (RMD) is commonly applied. The rate-distortion optimization (RDO) process to decide the best mode is too complex so that RMD chooses the candidate modes with a simple process and sends the candidates to RDO process. However, for large-size blocks, the RMD also requires considerable computations. In this paper, a down-sampling scheme is proposed for the RMD process. The reference pixel loading, predicted pixel generation are performed using the down-sampled pixel data. When the proposed scheme is applied to the RMD, the computational complexity is reduced by 70% with a marginal bitrate increase of 0.04%. In terms of area of hardware-based RMD, the gate count and the buffer size is reduced 33% and 66%, respectively.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.8
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• pp.104-113
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• 2014

The existing rough mode decision (RMD) algorithm, used in HEVC standard loses the coding efficiency and wastes encoding time when encoding using transform skip mode (TSM) because the RMD algorithm in HEVC uses a selection method that is designed for DCT, not for TSM. This paper proposes a new RMD algorithm for TSM in HEVC. Our proposed RMD algorithm enhances the coding efficiency by employing a new cost function to increase the probability of selecting the best intra prediction mode for TSM. In addition, it reduces the encoding time by skipping the encoding process of least feasible TSM based on a newly proposed threshold value. The experiment results show that the proposed method achieves coding gains of -0.3% for screen contents with a 10% reduction in encoding time compared to those of the HEVC standard.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.10
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• pp.154-163
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• 2014

In this paper, there is suggested a fast intra prediction mode decision method in HEVC. To reduce the number of candidates in rough mode decision (RMD) process and rate-distortion optimization (RDO) process, the edge information and relative RMD cost are utilized. The experiment results show that the proposed method reduces encoding run-time by 26.81% with a negligible coding loss of 0.79% BD-rate on average.

• Journal of Korean Medicine Rehabilitation
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• v.21 no.1
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• pp.115-123
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• 2011

Objectives : This study was designed to investigate the correlation coefficients among Oswestry low-back pain disability index(ODI), Roland-Morris disability questionnaire (RMD), visual analogue scale(VAS), lumbar lordosis angle(LLA), Cobb's angle and Ferguson's angle(FA). Methods : We measured LLA, Cobb's angle, and FA of 42 students. Then we researched ODI, RMD and VAS of all students, and analyzed correlations coefficient among all of them. Results : 1. There was significant correlation among VAS, RMD, ODI. 2. There was significant correlation between ODI and Cobb's angle. 3. There was no significant correlation between LLA, FA, Cobb's angle and VAS. 4. There was no significant correlation among LLA, FA, Cobb's angle and RMD. Conclusions : According to above results, there was no significant correlation between lumbosacral balance and low back pain except between ODI and Cobb's angle. On the other hand, there was significant correlation among RMD, ODI and VAS.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.8
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• pp.1128-1136
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• 1989

The power spectral densities of run-length-limited(RLL) minimum-bandwidth(MB) line codes are obtained for some values of the zero probability of input data. They can be obtianed by implementing a computer program for the G.L. Cariolaro's algorithm. Using the program we calculate the power spectra of the known RLL MB line codes, such as VDB5, TIB5, VMDB5, RMD35, DRMD35, RMD45, and RMD33, and compare the characteristics of them. Specially, the relationship between eye widths and power spectra is analyzed.

• Proceedings of the Safety Management and Science Conference
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• 2012.04a
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• pp.293-300
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• 2012

Reliability measures of questionnaire and ${\chi}^2$ contingency tests of categorized responses are most practical tools to analyze the characteristics of subjects of survey study. This research evaluates the Cronbaha's reliability measures by using Repeated Measure Design (RMD) with illustrated MINITAB examples. In addition, ${\chi}^2$ statistics of each cell of categorized tables can be effectively interpreted with the symmetric plot of correspondence analysis. The practical example is also discussed to provide comprehensive understanding of topic.

• Proceedings of the Safety Management and Science Conference
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• 2011.04a
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• pp.95-99
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• 2011

The research analyzes structure models of Repeated Measurement Design (RMD) and Hierarchical Design (HD). The experimental unit of RMD model is living organisms, such as human. In contrast, HD is used when all the factors are random. The HD models are derived from R:B:A, R:C:B:A and R:C:($A{\times}B$).

• Journal of Broadcast Engineering
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• v.19 no.2
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• pp.158-165
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• 2014

High Efficiency Video Coding (HEVC), the latest video coding standard, has twice of the compression efficiency compared to AVC/H.264 under the same image quality condition. To obtain the improved efficiency, however, it was adopted for many methods which need complicated calculation, and the time complexity of HEVC was increased more than that of AVC/H.264. To solve this problem, the various fast algorithms have been researched. In this paper, we propose a fast intra prediction mode decision method which uses result of Rough Mode Decision (RMD) and Most Probable Mode (MPM). The proposed method selects a best predicted mode by comparing each predicted directions which are calculated through RMD and MPM. We applied the proposed method to HM 10.0 and conducted an comparing experiment in All-Intra environment. The experiment result showed that total encoding time is reduced by about 26% on average with about a 0.8% loss of BD-rate.

• The Journal of the Korea Contents Association
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• v.14 no.9
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• pp.102-109
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• 2014

Intra prediction in HEVC is also significantly improved from H.264/AVC with the increased prediction modes up to 35 that results in increase of the complexity cost. Hence, a fast intra mode decision algorithm is required for real-time applications. A fast intra mode decision is proposed in this paper for further complexity reduction in addition to the RMD (Rough Mode Decision) that has been adopted into the HEVC reference software, referred to as HM, for fast intra prediction. The proposed method reduces the complexity of intra mode decision by limiting the number of search modes in both steps of RMD and the final mode decision. Experimental results show that the proposed method provide about 13.2% encoding time reduction with 1.0% BD-rate increase on average over test sequences in HM 12.0.

• The KIPS Transactions:PartC
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• v.10C no.7
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• pp.899-914
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• 2003

It is generally accepted that self-similar (or fractal) processes may provide better models for teletraffic in modern telecommunication networks than Poisson Processes. If this is not taken into account, it can lead to inaccurate conclusions about performance of telecommunication networks. Thus, an important requirement for conducting simulation studies of telecommunication networks is the ability to generate long synthetic stochastic self-similar sequences. Three generators of pseudo-random self-similar sequences, based on the FFT〔20〕, RMD〔12〕 and SRA methods〔5, 10〕, are compared and analysed in this paper. Properties of these generators were experimentally studied in the sense of their statistical accuracy and times required to produce sequences of a given (long) length. While all three generators show similar levels of accuracy of the output data (in the sense of relative accuracy of the Horst parameter), the RMD- and SRA-based generators appear to be much faster than the generator based on FFT. Our results also show that a robust method for comparative studies of self-similarity in pseudo-random sequences is needed.