• Journal of Broadcast Engineering
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• v.12 no.5
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• pp.491-502
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• 2007

In this parer, we propose an efficient intra prediction mode decision scheme in Scalable Video Coding(SVC) which is an emerging video coding standard as an extension of H.264/MPEG-4 AVC(Advanced Video Coding). The proposed method in base on the characteristic of macroblock smoothness follows the statistical analysis of intra prediction mode in an enhancement layer and it decides a candidate intra prediction mode. We also propose an early termination scheme for Intra_BL mode decision where the RD cost value of Intra_BL is utilized. Simulation results show that the proposed method reduces 54.67% of the computation complexity of intra prediction coding, while the degradation in video quality is negligible; for low QP values, the average PSNR loss is very negligible, equivalently the bit rate increases by 0.011%. For high QP values, the average PSNR loss is less than 0.01dB, which equals to 0.249% increase in bitrate.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.321-325
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• 2009

Sub-pel level motion estimation contributes to significant increase in R-D performance for H.264|MPEG 4 Part 10 AVC. However, several supplements, such as interpolation, block matching, and Hadamard transform which entails large computational complexity of encoding process, are essential to find best matching block in sub-pel level motion estimation and compensation. In this paper, a fast motion estimation scheme in sub-pel accuracy is proposed based on a parabolic model of SAD to avoid such computational complexity. In the proposed scheme, motion estimation (ME) is only performed in integer-pel levels and the following sub-pel level motion vectors are found from the parametric SAD model for which the model parameters are estimated from the SAD values obtained in the integer-pel levels. Fall-back check is performed to ensure the validity of the parabolic SAD model with the estimated parameters. The experiment result shows that the proposed scheme can reduce the motion estimation time up to about 30% of the total ME times in average with negligible amount of PSNR drops (0.14dB in maximum) and bit increments (2.54%in maximum).

• Journal of Broadcast Engineering
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• v.13 no.3
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• pp.328-338
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• 2008

Multi-view video coding (MVC) based on H.264/AVC encodes multiple views efficiently by using a prediction scheme that exploits inter-view correlation among multiple views. However, with the increase of the number of views and use of inter-view prediction among views, total encoding time will be increased in multiview video coding. In this paper, we propose a fast mode decision using both MB(Macroblock)-based region segmentation information corresponding to each view in multiple views and global disparity vector among views in order to reduce encoding time. The proposed method achieves on average 40% reduction of total encoding time with the objective video quality degradation of about 0.04 dB peak signal-to-noise ratio (PSNR) by using joint multi-view video model (JMVM) 4.0 that is the reference software of the multiview video coding standard.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.4
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• pp.889-891
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• 2017

Visible light communication technology, which is a communication using LED lighting, is defined by IEEE 802.15.7 WG and active research is under way. Visible light communication is advantageous not only to avoid interference with existing RF communication but also to provide location based service through accurate positioning by utilizing LOS (Line of Sight) characteristic. Therefore, it is very easy and efficient to locate and track the user's location. In this paper, we implemented a visible light communication transceiver using USB interface for easy application to portable devices. It supports the mobility of mobile devices through internet protocol and showed BER performance of less than $10^{-3}dBm$ at over 1m, which is the height of lighting and smart device during walking.

• The Korean Journal of Pesticide Science
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• v.6 no.3
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• pp.218-223
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• 2002

The rate of hydrolysis of insecticide, O,O-diethyl-O-(1-phenyl-3-trifluoromethylpyrazol-5-yl)phosphorothioate (Flupyrazofos) have been investigated in 25% (v/v) aqueous dioxane (${\mu}=0.1M$) at $45^{\circ}C$. The hydrolysis mechanism of flupyrazofos proceeds through the specific acid ($A_{AC}2$) catalysis below pH 4.0, specific base ($B_{AC}2$) catalysis above pH 11.0 and general acid & base ($B_{AC}2$) catalysis between pH 5.0 and pH 10.0 via trigonal-bipyramidal ($d^2sp^3$) intermediate as evidence by solvent effect ($|m|{\ll}|{\ell}|$), rate equation ($kt=ko+k_H+ [H_3O^+]+k_{OH}[OH^-]$) and product analysis. The half-life ($T\frac{1}{2}$) of hydrolytic degradation in neutral media at $45^{\circ}C$ was ca. 3 months.

• Korean Journal of Plant Tissue Culture
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• v.24 no.3
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• pp.167-173
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• 1997

The embryogenic callus (EC), from which somatic embryos could be induced, was compared with nonembryogenic callus(NE) to study the origin and features of totipotent cell in water dropwort (Oenanthe stolonifera DC). To induce and maintain of EC and the NE, meristematic stem and immature floret were inoculated in MS media supplemented with 1 mg/L 2,4-D, and with 2.5 mg/L NAA and 5mg/L BA, respectively, The EC was not induced from the NE even after subculturing in MS medium supplemented with 1 mg/L 2,4-D. Plantlets were not regenerated from the NE in hormone-free medium. In histochemical comparison of the EC with the NE by light microscopy, the EC had smaller cells in size, dense cytoplasm, and more starch granules of cells compared to the NE cells. The cell from the EC, as observed by transmission electron microscopy, had smaller vaculoes, well developed ribosomes, mitochondria, and endoplasmic reticulum, whereas the cells from the NE had larger vacuoles and underdeveloped organelles. In protein pattern from NE, EC and Somatic embryo (SE), as analyzed by SDS polyacrylamide gel electrophoresis, different proteins specific for tissue were observed: 17 and 28 KD for NE, 50, 52, 57, 66, 68 KD for EC and 20 KD for SE. DNA polymorphism was also observed between EC and NE as analyzed by RAPD (randomly amplified polymorphic DNA) method. The origin of totipotent stem cell and the relationship between irreversible genomic change arose in differentiation and the loss of totipotency in plant were discussed.

• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.874-879
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• 1995

Magnetic properties of FeMoN, FeMoTaN, FeTaN and FeTaC films deposited by DC magnetron reactive sputter were investigated, and correlated with their microstructure. FeMoN films were not showen the soft magnetic prop¬erties, because of generated $Fe_{2}Mo$, $Fe_{3-2}N$ and $Fe_{4}N$ phases. Ta added films, however, effectivly retarded the $\alpha$-Fe grain growth and suppressed the generation of Fe nitrides or carbides during heat treatement. The soft magnetic properties of $B_{s}:15\;kG,\;H_{e}:0.25\;Oe,\;\mu':4000(at\;5\;MHz),\;and\;B_s:14.5\;kG,\;He:0.25\;Oe,\;\mu':2700(5MHz)$ were observed in $Fe_{78.8} Ta_{8.5}N_{12.7}\;and\;Fe{75.6}Ta_{8.1}C_{16.3}$ films, respectively.

• The Journal of Society for e-Business Studies
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• v.23 no.4
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• pp.19-39
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• 2018

Recently, fake news has attracted worldwide attentions regardless of the fields. The Hyundai Research Institute estimated that the amount of fake news damage reached about 30.9 trillion won per year. The government is making efforts to develop artificial intelligence source technology to detect fake news such as holding "artificial intelligence R&D challenge" competition on the title of "searching for fake news." Fact checking services are also being provided in various private sector fields. Nevertheless, in academic fields, there are also many attempts have been conducted in detecting the fake news. Typically, there are different attempts in detecting fake news such as expert-based, collective intelligence-based, artificial intelligence-based, and semantic-based. However, the more accurate the fake news manipulation is, the more difficult it is to identify the authenticity of the news by analyzing the news itself. Furthermore, the accuracy of most fake news detection models tends to be overestimated. Therefore, in this study, we first propose a method to secure the fairness of false news detection model accuracy. Secondly, we propose a method to identify the authenticity of the news using the social data broadly generated by the reaction to the news as well as the contents of the news.

• Journal of Broadcast Engineering
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• v.26 no.4
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• pp.441-452
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• 2021

In this paper, we propose a method for generating luma signal mapping function to improve the coding efficiency of luma signal mapping methods in LMCS. In this paper, we propose a method to reflect the cognitive and perceptual features by multiplying the attention map of convolutional neural networks on local spatial variance used to reflect local features in the existing LMCS. To evaluate the performance of the proposed method, BD-rate is compared with VTM-12.0 using classes A1, A2, B, C and D of MPEG standard test sequences under AI (All Intra) conditions. As a result of experiments, the proposed method in this paper shows improvement in performance the average of -0.07% for luma components in terms of BD-rate performance compared to VTM-12.0 and encoding/decoding time is almost the same.

• Journal of Broadcast Engineering
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• v.27 no.4
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• pp.569-580
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• 2022

In this study, we investigated the effect of peripheral blur on binocular fusion to resolve binocular fusion failure which is one of the 3D visual fatigues in the perspective of human visual system. With stimulus having discrete disparity change, binocular fusion failure rate for target stimulus having crossed and uncrossed disparity decreased. And target stimulus having continuous disparity also required relatively larger binocular disparity when peripheral blur was presented with target stimulus rather than when peripheral blur was not presented. These results imply that peripheral blur facilitated binocular fusion in the situation of binocular disparity change, and suggest that considering the characteristics of human three-dimensional visual systems, manipulating 3D contents can improve visual discomfort caused by binocular displays at low costs.