• The Journal of the Korea Contents Association
• /
• v.9 no.4
• /
• pp.27-33
• /
• 2009

Selection of the Lagrangian multiplier is a key factor to determine the performance of Rate-Distortion Optimization (RDO) in video coding. JM, reference S/W of H.264, employs only one RDO model for all macroblock. However, since the characteristics of macroblocks are different, RDO model adaptive to their characteristics can give some performance improvement. In this paper, we propose an RDO algorithm adaptive to characteristics of macroblocks. We empirically obtain the optimal Lagrangian multipliers considering characteristics of macroblocks. For performance evaluation, the proposed method is applied to JM10.2 and, as a result, we have PSNR gain of 0.2dB on average.

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

• Journal of Broadcast Engineering
• /
• v.20 no.6
• /
• pp.862-870
• /
• 2015

The RDO (Rate Distortion Optimization) process of HEVC results in good coding efficiency, but relatively requires much encoding time. In order to reduce the encoding time of RDO process, this paper proposes a method of fast intra prediction mode decision using DCT coefficients distributions and the existence of DCT coefficients. The proposed fast Intra coding sets the number of intra prediction mode candidates to three(3) from the RMD (Rough Mode Decision) process in HM16.0 reference SW and reduces the number of candidates one more time by investigating DCT coefficients distribution. After that, if there exists a quantized DCT block having all zero coefficient values for a specific candidate before the RDO process, the candidate is chosen without the RDO process. The proposed method reduces the encoder complexity on average 46%, while the coding efficiency is 2.1% decreased compared with the HEVC encoder.

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

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2015.07a
• /
• pp.546-548
• /
• 2015

HEVC(High Efficiency Video Coding)는 JCT-VC(Joint Collaborative Team on Video Coding)라는 ITU-T(VCEG)와 ISO-IEC(MPEG)가 공동으로 진행한 팀이 만들어낸 표준화이다. 이 표준화된 코덱에서 율-왜곡 최적화(RDO)는 실행함에 있어 높은 성능 향상을 보이지만 상대적으로 많은 부호화 시간이 요구된다. RDO 의 부호화 시간을 줄이기 위해서 이 논문에서는 변환 계수를 이용한 고속 인트라 예측 방법을 제안한다. 기존 HEVC 에서는 RMD(Rough Mode Decision)를 통해 상위 N 개의 후보를 구하고 MPM(Most Probable Mode)을 거쳐 나온 후보들의 수의 합을 가지고 RDO 를 구하게 된다. 여기서 제안하는 고속 인트라 예측 방법은 RDO 를 구하기 전에 나왔던 N 개의 후보에서 이산 여현 변환(DCT) 계수를 이용하여 예측 모드의 수를 한 번 더 줄임으로써 RDO 수행시간을 줄이는 방법이다. 이 방법은 기존 HEVC 부호화 방법보다 적은 손실에도 불구하고 높은 속도 향상을 보인다.

• The Journal of Society for e-Business Studies
• /
• v.11 no.3
• /
• pp.53-71
• /
• 2006

In order to cope with the rapidly changing product development environment, individual manufacturing enterprises are forced to collaborate with each other through establishing a virtual organization. In collaboration, designated organizations work together for mutual gain based on product data interoperability. However, product data interoperability is not fully facilitated due to semantic inconsistency among product data models of individual enterprises. In order to overcome the semantic inconsistency problem, this paper proposes a reference ontology, Reference Domain Ontology(RDO), and a methodology for product data interoperability with semantic consistency using RDO. RDO describes semantics of product data model and metamodel for all application domains in a virtual organization. Using RDO, application domains in a virtual organization can easily understand the product data models of others. RDO is agile and temporal such that it is created with the formation of a virtual organization, copes with changes of the organization, and disappears with the vanishment of the organization. RDO is built by a hybrid approach of top-down using a upper ontology and bottom-up based on the merging of ontologies of application domains in a virtual organization. With this methodology, every domain in a virtual organization can achieve product data model interoperability without model transformation.

• Smart Media Journal
• /
• v.3 no.4
• /
• pp.16-21
• /
• 2014

HEVC is the latest joint video coding standard with ITU-T SG16 WP and ISO/IEC JTC1/SC29/WG11. Its coding efficiency is about two times compared to H.264 high profile. Intra prediction has 35 directional modes including dc and planer. However an accurate mode decision on lots of modes with SSE is too costly to implement it with hardware. The key idea of this paper is a DCT shared architecture to reduce the complexity of HEVC intra encoder. It is to use same DCT block to quantize as well as to calculate SSE in RDO. The proposed intra encoder uses two step mode decision to lighten complexity with simplified RDO blocks and shares the transform resources. Its BD-rate increase is negligible at 20% on hardware aspect and the operating clock frequency is 300MHz@60fps on FHD ($1920{\times}1080$) image.

• Structural Engineering and Mechanics
• /
• v.56 no.5
• /
• pp.707-726
• /
• 2015

There is a growing trend of considering uncertainty in optimization process since last few decades. In this regard, Robust Design Optimization (RDO) scheme has gained increasing momentum because of its virtue of improving performance of structure by minimizing the variation of performance and ensuring necessary safety and feasibility of constraint under uncertainty. In the present study, RDO of reinforced concrete folded plate and shell structure has been carried out incorporating uncertainty in the relevant parameters by Monte Carlo Simulation. Folded plate and shell structures are among the new generation popular structures often used in aesthetically appealing constructions. However, RDO study of such important structures is observed to be scarce. The optimization problem is formulated as cost minimization problem subjected to the force and displacements constraints considering dead, live and wind load. Then, the RDO is framed by simultaneously optimizing the expected value and the variation of the performance function using weighted sum approach. The robustness in constraint is ensured by adding suitable penalty term and through a target reliability index. The RDO problem is solved by Sequential Quadratic Programming. Subsequently, the results of the RDO are compared with conventional deterministic design approach. The parametric study implies that robust designs can be achieved by sacrificing only small increment in initial cost, but at the same time, considerable quality and guarantee of the structural behaviour can be ensured by the RDO solutions.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.20 no.9
• /
• pp.2731-2743
• /
• 1996

When modeling error is large of plant is time-varying, it is hard to obtain good robust performance and robust stability by conventional contorl methods. Here, we need to design a robust controller bearing modeling error. In this paper, based on recently developed Time Delay Control(TDC) and Disturbance Observer the output feedback Robust Disturbance Observer(RDO), which is easily combined with general linear control, is proposed. Proposed RDO is derived from extending the main idea of Disturbance Observer to multi-input multi-output linear system. RDO solves robust stability problem of Disturbance Observer and has the robust performance same as nominal performance. RDO controlled dual stage positioning system shows excellent robust performance.

• Structural Engineering and Mechanics
• /
• v.53 no.6
• /
• pp.1127-1141
• /
• 2015

The optimum design of liquid column dampers in seismic vibration control considering system parameter uncertainty is usually performed by minimizing the unconditional response of a structure without any consideration to the variation of damper performance due to uncertainty. However, the system so designed may be sensitive to the variations of input system parameters due to uncertainty. The present study is concerned with robust design optimization (RDO) of liquid column vibration absorber (LCVA) considering random system parameters characterizing the primary structure and ground motion model. The RDO is obtained by minimizing the weighted sum of the mean value of the root mean square displacement of the primary structure as well as its standard deviation. A numerical study elucidates the importance of the RDO procedure for design of LCVA system by comparing the RDO results with the results obtained by the conventional stochastic structural optimization procedure and the unconditional response based optimization.