• IEIE Transactions on Smart Processing and Computing
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• 제5권5호
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• pp.323-326
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• 2016

High Efficiency Video Coding (HEVC) adopts intra transform skip mode, in which a residual block is directly quantized in the pixel domain without transforming the block into the frequency domain. Intra transform skip mode provides a significant coding gain for screen content. However, when intra-prediction errors are not transformed, the errors are often correlated along the intra-prediction direction. This paper introduces a residual differential pulse code modulation (DPCM) method for the intra-predicted and transform-skipped blocks to remove redundancy. The proposed method performs pixel-by-pixel residual prediction along the intra-prediction direction to reduce the dynamic range of intra-prediction errors. Experimental results show that the transform skip mode's Bjøntegaard delta rate (BD-rate) is improved by 12.8% for vertically intra-predicted blocks. Overall, the proposed method shows an average 1.2% reduction in BD-rate, relative to HEVC, with negligible computational complexity.

• Journal of Microbiology
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• 제44권2호
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• pp.137-144
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• 2006

The problems associated with gene identification and the prediction of gene structure in DNA sequences have been the focus of increased attention over the past few years with the recent acquisition by large-scale sequencing projects of an immense amount of genome data. A variety of prediction programs have been developed in order to address these problems. This paper presents a review of the computational approaches and gene-finders used commonly for gene prediction in eukaryotic genomes. Two approaches, in general, have been adopted for this purpose: similarity-based and ab initio techniques. The information gleaned from these methods is then combined via a variety of algorithms, including Dynamic Programming (DP) or the Hidden Markov Model (HMM), and then used for gene prediction from the genomic sequences.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1998년도 창립기념 춘계학술대회 논문집
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• pp.211-218
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• 1998

The demand prediction becomes an essential mean to utilize efficiently finite traffic facilities and to provide the optimized schedules for transportation system. The demand prediction is one of the critical complex management schemes for distibuting resources of transportation service by means of computer system. The construction of a prediction model is based on data granulization, followed by processing the raw input data and evaluating the predicted output values. A large number of economic-social parameters are also to be implemented in conventional prediction models which are only based on a sequence of past data. The proposed prediction models are classified by static and dynamic characteristics and its performances are evaluated utilizing computer simulation.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -1
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• pp.176-179
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• 2002

In recent years, an increasing amount of computer network research has focused on the problem of cluster system in order to achieve higher performance and lower cost. The load unbalance is the major defect that reduces performance of a cluster system that uses parallel program in a form of SPMD (Single Program Multiple Data). Also, the load unbalance is a problem of MPP (Massive Parallel Processors), and distributed system. The cluster system is a loosely-coupled distributed system, therefore, it has higher communication overhead than MPP. Dynamic load balancing can solve the load unbalance problem of cluster system and reduce its communication cost. The cluster systems considered in this paper consist of P heterogeneous nodes connected by a switch-based network. The master node can predict the average execution time of tasks for each slave node based on the information from the corresponding slave node. Then, the master node redistributes remaining tasks to each node considering the predicted execution time and the communication overhead for task migration. The proposed dynamic load balancing uses execution time prediction to optimize the task redistribution. The various performance factors such as node number, task number, and communication cost are considered to improve the performance of cluster system. From the simulation results, we verified the effectiveness of the proposed dynamic load balancing algorithm.

• Journal of Advanced Research in Ocean Engineering
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• 제1권4호
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• pp.252-267
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• 2015

Offshore structures might encounter several environmental and operating conditions during their lifetime of several decades. In order to predict the dynamic behavior of offshore structures, several simulation cases should be considered to deal with all the combinations of ocean environments and operating conditions. Because a sophisticated time-domain coupled dynamic analysis requires an extremely large amount of computational time to handle all the possible cases, an efficient preliminary process to prescreen the probability of severe environmental conditions can be helpful in downsizing the number of simulation cases and computational effort. In this study, a prescreening procedure to reduce the number of environmental conditions for dynamic analyses of offshore structures is proposed. For the efficiency of the procedure, frequency-domain theories were adopted to estimate the platform offset, using quasi-static analyses in line tension prediction. The results were validated by comparing with those of dynamic analysis coupled between platform and mooring lines, and reasonable agreement was observed. In addition, the characteristics of environmental conditions classified to be severe to the system were investigated through the application of the developed prescreening scheme to several actual environmental conditions.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 춘계학술대회논문집
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• pp.427-733
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• 2003

Adiabatic shear bands have been observed in the serrated chip during high strain rate metal cutting process of medium carbon steel and titanium alloy. The recent microscopic observations have shown that dynamic recrystallization occurs in the narrow adiabatic shear bands. However the conventional flow stress models such as the Zerilli-Armstrong model and the Johnson-Cook model, in general, do not predict the occurrence of dynamic recrystallization (DRX) in the shear bands and the thermal softening effects accompanied by DRX. In the present study, a strain hardening and thermal softening model is proposed to predict the adiabatic shear localized chip formation. The finite element analysis (FEA) with this proposed flow stress model shows that the temperature of the shear band during cutting process rises above 0.5T$\sub$m/. The simulation shows that temperature rises to initiate dynamic recrystallization, dynamic recrystallization lowers the flow stress, and that adiabatic shear localized band and the serrated chip are formed. FEA is also used to predict and compare chip formations of two flow stress models in orthogonal metal cutting with AISI 1045. The predictions of the FEA agreed well with the experimental measurements.

• Wind and Structures
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• 제20권6호
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• pp.719-737
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• 2015

Full scale measurement on the structural dynamic characteristics and Vortex-induced Vibrations (VIV) of a long-span suspension bridge with a central span of 1650 m were conducted. Different Finite Element (FE) modeling principles for the separated twin-box girder were compared and evaluated with the field vibration test results, and the double-spine model was determined to be the best simulation model, but certain modification still needs to be made which will affect the basic modeling parameters and the dynamic response prediction values of corresponding wind tunnel tests. Based on the FE modal analysis results, small-scaled and large-scaled sectional model tests were both carried out to investigate the VIV responses, and probable Reynolds Number effects or scale effect on VIV responses were presented. Based on the observed VIV modes in the field measurement, the VIV results obtained from sectional model tests were converted into those of the three-dimensional (3D) full-scale bridge and subsequently compared with field measurement results. It is indicated that the large-scaled sectional model test can probably provide a reasonable and effective prediction on VIV response.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.869-874
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• 2001

In order that precision equipment using high precision industrial operate normally. vibration criteria of expected area that equipment be set up is micrometer level. that method is a trust design for apply to in field, when there attend to quantifiable method. Hence, semi -empirical method that using on the basis of experimental data about undefined information (properities of vibration source, dynamic properities of structure, etc.,) for prediction of vibration response make the use of dynamic structure design of semiconductor ＆ TFT-LCD in the inside and outside country. Like this, for doing an optimal design of dynamic about structure, it is best important to get trust data that apply to semi-empirical method that is method of prediction vibration level. In this paper, on the basis of experimental data which was offered by a manufacturing company Of precisin equipment that plan to set up in semiconductor factory, we predicted vibration response on expected area that equipment be set up.

• 한국해양공학회지
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• 제20권3호
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• pp.54-60
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• 2006

For optimal design of a deep-sea ocean mining collector system, based on self-propelled mining vehicle, it is imperative to develop and validate the dynamic model of a tracked vehicle traveling on soft deep seabed. The purpose of this paper is to evaluate the fidelity of the dynamic simulation model by means of response surface methodology. Various statistical techniques related to response surface methodology, such as outlier analysis, detection of interaction effect, analysis of variance, inference of the significance of design variables, and global sensitivity analysis, are examined. To obtain a plausible response surface model, maximum entropy sampling is adopted. From statistical analysis and prediction for dynamic responses of the tracked vehicle, conclusions will be drawn about the accuracy of the dynamic model and the performance of the response surface model.

• 한국멀티미디어학회논문지
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• 제9권1호
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• pp.59-72
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• 2006

유 무선 네트워크의 기술의 발전과 단말기의 소형화 기술은 이동 환경에서 다양한 단말기를 이용하여 멀티미디어 콘텐츠를 이용할 수 있게 만들었다. 그러나 네트워크의 구성과 단말기들의 성능이 다양해짐에 따라, 동일한 품질의 컨텐츠를 다양한 이동 환경에 위치한 사용자에게 서비스를 제공하는 것은 매우 어려운 일이다. 그러므로 멀티미디어 스트리밍 시스템은 사용자의 네트워크와 단말기 환경을 고려하여 적응적으로 서비스를 제공하여 한다. 트랜스코딩 기법은 다양한 네트워크 환경에서 적응적인 비디오 스트리밍 서비스를 제공하기 위한 하나의 방법이다. 본 논문은 다양한 네트워크 환경에서 비디오 스트림을 서비스하기 위해 예측주기를 이용한 동적 프레임 삭제 트랜스코딩 기법을 제안한다. 제안된 트랜스코더에서는 부호기의 예측주기와 프레임율을 조절하는 삭제주기를 이용하여 트랜스코딩 과정에서 소요되는 시간을 최적화 할 수 있다. 실험 결과, 기존의 동적 프레임 삭제 트랜스코딩 기법에 비해서 본 논문에서 제안한 기법을 PSNR값은 유사한 반면에 계산 복잡도에서 매우 높은 성능 향상을 보였다.