• Korean Journal of Biological Psychiatry
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• v.20 no.3
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• pp.63-65
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• 2013

The new edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) is published by the American Psychiatric Association. The diagnostic systems for mental disorders have come under criticism for relying on presenting signs and symptoms with the result that they do not adequately reflect relevant neurobiological and behavioral systems. Finally, the National Institute of Mental Health (NIMH) in the United States has suggested the Research Domain Criteria (RDoC) to develop a research classification system based upon dimensions of neurobiology and behavioral aspect. The present review introduces the RDoC as a new reaseach framework.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.3C
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• pp.250-257
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• 2006

In this paper, we propose an efficient algorithm for the RDO mode decision in H.264/AVC encoder. Based on the properties of DCT coefficients and the RDO mode decision processing, we derive a new condition for detecting an error block having all-zero DCT coefficient (AZCB). (I)DCT, (I)Q, and entropy coding are skipped for AZCBs in the proposed algorithm. It makes the reduction of the computational complexity for the RDO mode decision. Simulation results show that the proposed algorithm achieves computational saving over 40% compared to the conventional method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.11C
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• pp.1098-1107
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• 2005

The emerging H.264/AVC video coding standard improves coding performance significantly by adopting many advanced techniques. This is achieved at the expense of great increasing encoder complexity. Specifically the intra prediction using RDO examines all possible combinations of coding modes, which depend on spatial directional correlation with adjacent blocks. For 4${\times}$4 luma blocks, there are 9 modes, and for 16${\times}$16 luma and 8${\times}$8 chroma blocks, there are 4 modes, respectively. Therefore the number of mode combinations for each macroblock is 592. This paper presents a method to reduce the RDO complexity using simple directional masks and neighboring modes. According to the proposed method, we reduce the number of mode combinations to 132 at the most. Experimental results show the proposed method reduces the encoding time up to $70\%$ with negligible loss of PSNR and bitrate increase compared to the H.264/AVC exhaustive search.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.8C
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• pp.591-597
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• 2008

In this paper, we present a improved rate distortion optimization (RDO) for H.264 intra coding. By using new mode decision criteria pass for $I4{\times}4$ in company with the original RDO, the proposed method can achieve the better coding efficiency comparing with the original RDO. Our experimental results show that the proposed algorithm can archive about $0.64{\sim}1.6578%$ bit rate decrease at the same PSNR and $0.049{\sim}0.101dB$ PSNR increase at the same bit rate.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.1C
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• pp.34-44
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• 2008

In this paper, a new rate-distortion estimation method is proposed for fast rate-distortion optimized(RDO) mode decision in H.264 encoder. A bit-rate and distortion should be calculated by encoding and reconstruction of each macroblock mode in order to select the optimal RDO mode. To reduce the computations for getting them, a bit-rate and distortion is efficiently estimated in DCT domain. Simulation results show that the proposed method achieves computational saving about 81% of RDO mode decision and saves about 26% of total encoding time without noticeable degradation in coding performance.

• Psychiatry investigation
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• v.15 no.11
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• pp.1011-1018
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• 2018

The analysis of extracellular vesicles has been accelerated because of the technological advancements in omics methods in recent decades. Extracellular vesicles provide multifaceted information regarding the functional status of the cells. This information would be critical in case of central nervous system cells, which are confined in a relatively sealed biological compartment. This obstacle is more dramatic in psychiatric disorders since their diagnosis primarily depend on the symptoms and signs of the patients. In this paper, we reviewed this rapidly advancing field by discussing definition of extracellular vesicles, their biogenesis and potential use as clinical biomarkers. Then we focused on their potential use in psychiatric disorders in the context of diagnosis and treatment of these disorders. Finally, we tried to combine the RDoC (Research Domain Criteria) with the use of extracellular vesicles in psychiatry research and practice. This review may offer new insights in both basic and translational research focusing on psychiatric disorders.

• Korean Journal of Psychosomatic Medicine
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• v.27 no.1
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• pp.1-12
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• 2019

The behavioural patterns of individuals in the same species are very diverse. The phenomenon in which different behavioural phenotypes are maintained in the same species for long time can be explained by niche specialization or frequency dependent selection, but it has not been proven yet. Especially, the high prevalence of mental illnesses as extreme behaviour patterns is one of the challenges of evolutionary psychology. From an evolutionary point of view, several frameworks for studying various patterns of behaviours or psychopathologies may be proposed. In this paper, I briefly explain animal models, personality factor models, DSM-IV multiaxial models, FSD models, and RDoC models, and discuss their advantages and disadvantages, focusing on the evolutionary approach to behavioural variation among individuals.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.11C
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• pp.1077-1084
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• 2006

This paper proposed a fast algorithm to reduce the amount of calculation for inter prediction which takes a great deal of the operational time in H.264/AVC. This algorithm decides a search range according to the direction of predicted motion vector, and then performs an adaptive spiral search for the candidates with JM(Joint Model) FME(Fast Motion Estimation) which employs the rate-distortion optimization(RDO) method. Simultaneously, it decides a threshold cost value for each of the variable block sizes and performs the motion estimation for the variable search ranges with the threshold. These activities reduce the great amount of the complexity in inter prediction encoding. Experimental results by applying the proposed method .to various video sequences showed that the process time was decreased up to 80% comparing to the previous prediction methods. The degradation of video quality was only from 0.05dB to 0.19dB and the compression ratio decreased as small as 0.58% in average. Therefore, we are sure that the proposed method is an efficient method for the fast inter prediction.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.4C
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• pp.321-329
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• 2008

H.264/AVC video coding standard enables a considerably higher improvement in coding efficiency compared with previous standards such as MPEG-2, H.263 and MPEG-4. To achieve this, for each macro-block in H.264/AVC, Rate-Distortion Optimization (RDO) technique is employed to select the best motion vector, reference frame, and macro-block mode. As a result, computational complexity is increased significantly whereas RDO achieve higher improvement. This paper presents fast intra mode selection algorithm based on constraints of frequency characteristics which are derived from intra coding modes of H.264/AVC. First of all, we observe the features of each intra mode through the frequency analysis of image. And then proposed Frequency Error Costs (FECs) are calculated to select the best mode which has minimum cost. Computational complexity is considerably reduced because rate-distortion costs only calculate the candidate modes which are set of best mode and its neighbouring two modes. Experimental results show that proposed algorithm reduces the complexity dramatically maintaining the rate-distortion performance compared with H.264/AVC reference software.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.1C
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• pp.63-71
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• 2009

In this paper, a new low-complexity distortion estimation method for H.264 rate-distortion optimized mode decision is proposed. The coding processes, such as DCT, quantization, inverse quantization, inverse DCT, and reconstruction are needed to compute the distortion in an H.264 encoder. To reduce these processes, we estimate distortion using integer operations with coefficients obtained in the quantization process. Inverse quantization, inverse DCT, and reconstruction processes are not needed by the proposed method. For quantization parameters 24 to 36, experimental results show that the time saving of rate-distortion optimized mode decision is on average 29 % and as high as 42 % with negligible degradation in coding performance.