• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.4
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• pp.1730-1747
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• 2018

Multi-view video plus depth (MVD) is a mainstream format of 3D scene representation in free viewpoint video systems. The advanced 3D extension of the high efficiency video coding (3D-HEVC) standard introduces new prediction tools to improve the coding performance of depth video. However, the depth video in 3D-HEVC is time consuming. To reduce the complexity of the depth video inter coding, we propose a fast coding unit (CU) size and mode decision algorithm. First, an off-line trained Bayesian model is built which the feature vector contains the depth levels of the corresponding spatial, temporal, and inter-component (texture-depth) neighboring largest CUs (LCUs). Then, the model is used to predict the depth level of the current LCU, and terminate the CU recursive splitting process. Finally, the CU mode search process is early terminated by making use of the mode correlation of spatial, inter-component (texture-depth), and inter-view neighboring CUs. Compared to the 3D-HEVC reference software HTM-10.0, the proposed algorithm reduces the encoding time of depth video and the total encoding time by 65.03% and 41.04% on average, respectively, with negligible quality degradation of the synthesized virtual view.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.3
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• pp.1195-1211
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• 2016

The emerging video coding standard High Efficiency Video Coding (HEVC) has shown almost 40% bit-rate reduction over the state-of-the-art Advanced Video Coding (AVC) standard but at about 40% computational complexity overhead. The main reason for HEVC computational complexity is the inter prediction that accounts for 60%-70% of the whole encoding time. In this paper, we propose several fast coding unit (CU) encoding schemes based on the Merge mode and motion estimation information to reduce the computational complexity caused by the HEVC inter prediction. Firstly, an early Merge mode decision method based on motion estimation (EMD) is proposed for each CU size. Then, a Merge mode based early termination method (MET) is developed to determine the CU size at an early stage. To provide a better balance between computational complexity and coding efficiency, several fast CU encoding schemes are surveyed according to the rate-distortion-complexity characteristics of EMD and MET methods as a function of CU sizes. These fast CU encoding schemes can be seamlessly incorporated in the existing control structures of the HEVC encoder without limiting its potential parallelization and hardware acceleration. Experimental results demonstrate that the proposed schemes achieve 19%-46% computational complexity reduction over the HEVC test model reference software, HM 16.4, at a cost of 0.2%-2.4% bit-rate increases under the random access coding configuration. The respective values under the low-delay B coding configuration are 17%-43% and 0.1%-1.2%.

• Journal of Korea Foundry Society
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• v.10 no.1
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• pp.57-63
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• 1990

Continuous casting of the $Al-CuAl_2$ eutectic composite was carried out by the upward continuous casting process. The morphology of the eutectic growth and the stability of solid-liquid interface were investigated under various growth conditions. It was possible to get the planar solid-liquid interface at the condition of $G_L/R$＝$3.6{\times}10^3^{\circ}Csec/mm^2$. And the colony structures were formed at the conditions of $G_L/R$ < $R=0.33{\times}10^3^{\circ}Csec/mm^2$. The inter-lamellar spacing of $Al-CuAl_2$ eutectic composite was decreased with the increase of pulling speed. The reduction of inter-lamellar spacing & value of $G_L/R$ caused the increase of ultimate tensile strength and Rockwell hardness in $Al-CuAl_2$ eutectic composite.

• Journal of Information Processing Systems
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• v.18 no.2
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• pp.235-244
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• 2022

Many new techniques have been adopted in HEVC (High efficiency video coding) standard, such as quadtree-structured coding unit (CU), prediction unit (PU) partition, 35 intra-mode, and so on. To reduce computational complexity, the paper proposes two optimization algorithms which include fast CU depth range decision and fast PU partition mode decision. Firstly, depth range of CU is predicted according to spatial-temporal correlation. Secondly, we utilize the depth difference between the current CU and CU corresponding to the same position of adjacent frame for PU mode range selection. The number of traversal candidate modes is reduced. The experiment result shows the proposed algorithm obtains a lot of time reducing, and the loss of coding efficiency is inappreciable.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1697-1699
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• 2004

In this investigation, we have studied the diffusion of the $Cu^+$ ion in the Cu/Ta/SiOCH/Si and Cu/Ta/$SiO_2$/Si MIS-C structure. The Cu ions diffusion into the Ta barrier and SiOCH was examined by shift in flatband voltage of capacitance-voltage measurement and leakage current of current-voltage measurement. These evalution indicated that $Cu^+$ ion diffusion rate in Ta/SiOCH is considerably lower then the Ta/$SiO_2$ structure. And diffusion barrier Ta(50[nm]) is useful barrier against $Cu^+$ ion diffusion up to 450$^{\circ}C$.

• Journal of Broadcast Engineering
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• v.17 no.5
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• pp.765-780
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• 2012

In this paper, we propose a fast mode decision method that determines the coding unit depth for enhancement layers to improve an encoding speed of a scalable video encoder based on HEVC. To decide the coding unit depth of the enhancement layer, firstly, the coding unit depth of the corresponded coding unit in the basement layer is employed. At this stage, the final CU depth is decided by calculating the rate-distortion costs of one lower depth to one upper depth of the referenced depth. The proposed method can reduce a computational load since it does not calculate the rate-distortion costs for all the depths of a target CU. We found that the proposed algorithm decreases encoding complexity of 26% with approximately 1.4% bit increment, compared with the simulcast encoder of the HM 4.0.

• Journal of Multimedia Information System
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• v.8 no.3
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• pp.147-158
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• 2021

Versatile Video Coding (VVC) is the latest video coding standard developed by Joint Video Exploration Team (JVET). In VVC, the quadtree plus multi-type tree (QT+MTT) structure of coding unit (CU) partition is adopted, and its computational complexity is considerably high due to the brute-force search for recursive rate-distortion (RD) optimization. In this paper, we aim to reduce the time complexity of inter-picture prediction mode since the inter prediction accounts for a large portion of the total encoding time. The problem can be defined as classifying the split mode of each CU. To classify the split mode effectively, a novel convolutional neural network (CNN) called multi-level tree (MLT-CNN) architecture is introduced. For boosting classification performance, we utilize additional information including inter-picture information while training the CNN. The overall algorithm including the MLT-CNN inference process is implemented on VVC Test Model (VTM) 11.0. The CUs of size 128×128 can be the inputs of the CNN. The sequences are encoded at the random access (RA) configuration with five QP values {22, 27, 32, 37, 42}. The experimental results show that the proposed algorithm can reduce the computational complexity by 11.53% on average, and 26.14% for the maximum with an average 1.01% of the increase in Bjøntegaard delta bit rate (BDBR). Especially, the proposed method shows higher performance on the sequences of the A and B classes, reducing 9.81%~26.14% of encoding time with 0.95%~3.28% of the BDBR increase.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.81-81
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• 2007

Chemical mechanical polishing (CMP) 공정은 deep 서브마이크론 집적회로의 다층배선구조률 실현하기 위해 inter-metal dielectric (IMD), inter-layer dielectric layers (ILD), pre-metal dielectric (PMD) 층과 같은 절연막 외에도 W, Al, Cu와 같은 금속층을 평탄화 하는데 효과적으로 사용되고 있으며, 다양한 소자 제작 및 새로운 물질 등에도 광범위하게 응용되고 있다. 하지만 Cu damascene 구조 제작으로 인한 CMP 응용 과정에서, 기계적으로 깨지기 쉬운 65 nm의 소자 이하의 구조에서 새로운 저유전상수인 low-k 물질의 도입으로 인해 낮은 하력의 기계적 연마가 필요하게 되었다. 본 논문에서는 전기화학적 기계적 연마 적용을 위해, I-V 특성 곡선을 이용하여 active, passive, transient, trans-passive 영역의 전기화학적 특성을 알아보았으며, Cu 막의 표면 형상을 알아보기 위해 scanning electron microscopy (SEM) 측정과 energy dispersive spectroscopy (EDS) 분석을 통해 금속 화학적 조성을 조사하였다.

• Journal of Broadcast Engineering
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• v.27 no.3
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• pp.361-368
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• 2022

Quaternary tree plus multi-type tree (QT+MTT) structure was adopted in the Versatile Video Coding (VVC) standard as a block partitioning tool. QT+MTT provides excellent coding gain; however, it has huge encoding complexity due to the flexibility of the binary tree (BT) and ternary tree (TT) splits. This paper proposes a fast inter coding unit (CU) partitioning algorithm for BT and TT split types based on prediction accuracy functions using the mean of the absolute error (MAE). The MAE-based decision model was established to achieve a consistent time-saving encoding with stable coding loss for a practical low complexity VVC encoder. Experimental results under random access test configuration showed that the proposed algorithm achieved the encoding time saving from 24.0% to 31.7% with increasing luminance Bjontegaard delta (BD) rate from 1.0% to 2.1%.

• Transactions of Materials Processing
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• v.16 no.5 s.95
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• pp.375-380
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• 2007

The bimetals of home appliances are mainly manufactured by cladding process and these are almost consisted with Cu alloy and Ni alloy. But it is very difficult to clad these alloys, because the brittle $Cu_3O_4$ oxide film formed easily on Cu alloy surface during cladding process. Clad rolling and heat treatment processes were applied for the development of bimetals by using the Ni alloy and the 3 types of Cu alloys. Optical microstructure, micro-hardness, specific resistance, and deflection and line profile of newly processed bimetals specimens were observed and measured in this paper. Inter-diffusion was observed between Cu and Ni element in the interface of heat treated Cu alloy and Ni alloy clad material. The C1220 and Invar36 clad material showed the best property of deflection among the 3 kind of clad materials.