• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2022.11a
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• pp.8-9
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• 2022

최근 VVC(Versatile Video Coding) 표준 완료 이후 JVET(Joint Video Experts Team)에서는 NNVC(Neural Network-based Video Coding) EE(Exploration Experiment)를 통하여 화면내 예측을 포함한 신경망 기반의 부호화 기술들을 탐색하고 검증하고 있다. 본 논문에서는 VVC 에 채택되어 있는 다중 변환 선택(MTS: Multiple Transform Selection)에 따라서 적절한 예측 블록을 선택할 수 있는 TDIP(Transform-Dependent Intra Prediction) 모델을 제안한다. 실험결과 제안기법은 VVC 의 AI(All Intra) 부호화 환경에서 VTM(VVC Test Model) 대비 Y, U, V 에 각각 0.87%, 0.87%, 0.99%의 BD-rate 절감의 비디오 부호화 성능 향상을 보였다.

• Journal of Marine Life Science
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• v.9 no.1
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• pp.33-40
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• 2024

To understand the detrimental effects of triclosan on Java medaka (Oryzias javanicus) embryos, fertilized embryos were exposed to different concentrations (1, 10, 50, 100, 200, 400, 600, 800, and 1,000 ㎍ l^-1) of triclosan until hatching. Then, we examined the survival rate and developmental parameters as well as alterations in antioxidant constituents and DNA damage markers. The results showed dose-dependent mortality, hatching delays, and developmental abnormalities in the embryos. Additionally, there were significant increases in oxidative stress parameters and antioxidant responses, along with elevated DNA damage. These findings suggest that sublethal concentrations of triclosan induce toxic effects through oxidative stress on Java medaka embryos, as evidenced by changes in in vivo parameters and biochemical constituents.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.6
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• pp.476-481
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• 2004

The aim of this study was to formulate a sustained release system for indomethacin (IND) with rosin gum obtained from a pine tree. Rosin microparticles were prepared by a disper­sion and dialysis method without the addition of surfactant. In order to investigate the influence of solvents on the formation of colloidal microparitcles, various solvents like ethanol, DMF, DMAc, and acetone were used. The rosin microparticles containing IND were characterized by X­ray differactometry (XRD) and differential scanning calorimetry (DSC). The morphologies of rosin microparticles observed by scanning electron microscopy (SEM) were spherical. The solvents used to dissolve rosin significantly affected the drug content and drug release rate of IND. The release behaviors of IND from the rosin microparticles were dependent on the drug content and size of the particles. Rosin micorparticles with a higher drug content and of a larger particle size had a slower drug release rate. Also, the IND release rate from the rosin microparticles could be regulated by the rosin content in the microparticles. From these results, rosin microparticles have the potential of being used as a sustained release system of IND.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2955-2960
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• 2007

To control the coating thickness of zinc in the process of continuous hot-dip galvanizing, it is known from early day that the gas wiping through an air knife system is the most effective because of the obtainable of uniformity of coating thickness, possibility of thin coating, working ability in high speed and simplicity of control. But, the gas wiping using in the galvanizing process brings about a problem of splashing from the strip edge for a certain high speed of coating. And, it is known that the problem of splashing is caused mainly by the existence of separation bubble at the neighbor of the strip surface. In theses connections, in the present study, we proposed two kinds of air knife systems having the same expansion rate of nozzle, and the jet structures and coating thicknesses from a conventional and new proposed nozzles are compared. In numerical analysis, the governing equations consisted of two-dimensional time dependent Navier-Stokes equations, standard ${\kappa}-{\varepsilon}$ turbulence model to solve turbulence stress and so on are employed. As a result, it is found that it had better to use the constant rate nozzle from the point view of the energy saving to obtain the same coating thickness. Also, to reduce the size of separation bubble and to enhance the cutting ability at the strip, it is recommendable to use an air knife having the constant expansion rate nozzle.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.1
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• pp.73-84
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• 2014

The present paper includes recent research works on the estimation of physical properties like equivalence ratio and heat release rate of flame through chemiluminescence measurement. Modern combustion devices require a precise control to increase combustion stability as well as to suppress pollutant emissions. The determination of combustion characteristics from chemiluminescence provides practical advantages over other techniques. However, the technique is dependent on equivalence ratio, combustion pressure, inlet temperature, turbulent intensity and fuel type. The intensity ratio of $OH^*$ and $CH^*$ has a strong relation with an equivalence ratio for methane/air premixed flames. The global measurement of chemiluminescence is accepted as a good indicator for a global heat release rate.

• Korean Journal of Childcare and Education
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• v.9 no.6
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• pp.197-221
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• 2013

The purpose of this study was to examine the relationship between the child care support policies and the birth rate in 33 OECD countries. In the structural equation modelling, the birth rate was the dependent variable while the cash-support policies, the child-care facility service policies, and the tax benefits policies were the independent variables. The analysis showed that the most effective factor on the birth rate was the child-care facility service policies. Regarding the effectiveness of the policy expenses, the cash-support policies showed stable fluctuation of effectiveness according to the fluctuation of cash amount, the child-care facility service policies. In conclusion, in order to increase the effectiveness of the cash-support policies, the adequate cost calculation to decrease the parents' burden for child-bearing, re-allocation of budget, and support methods and timing should be continually discussed. In addition, for the better effectiveness of the facility service policies, more various, comprehensive and high-quality facility service policies that could balance home and work, should be implemented.

• Journal of the Korean Regional Science Association
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• v.31 no.3
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• pp.113-130
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• 2015

This study is to identify urban characteristics affecting obesity of elementary, middle and high school students. Most of previous studies in Korea discussed healthy city focusing on adults. We list up possible urban characteristic factors that are considered to affect adolescent obesity from previous studies, and then conduct regression analysis to find policy implications in urban planning. Based on the physical examination data of adolescent students in Seoul from the Ministry of Education, we set the rate of obese students by school as a dependent variable. Urban characteristic variables are set as explanatory variables, and measured by buffer analysis within 500m, 1000m and 1500m. The result of regression analysis shows that the obese rate of students increases with adults' lower education level, higher rate of non-apartment houses, older age of houses and more homogeneous land use. However, the result does not indicate that population density, accessibility to public transportation and the urban park are significant factors for adolescent obesity. Based on this result, urban planning policy for promoting adolescent health should be discussed further.

• Korean Journal of Materials Research
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• v.24 no.11
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• pp.625-631
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• 2014

To investigate the deformation properties of TiC-(5-20) mol% Mo solid solution single crystals at high temperature by compression testing, single crystals of various compositions were grown by the radio frequency floating zone technique and were deformed by compression at temperature from 1250K to 2270K at strain rates from $5.1{\times}10^{-5}$ to $5.9{\times}10^{-3}/s$. The plastic flow property of solid solution single crystals was found to be clearly different among a three-temperature range (low, intermediate and high temperature ranges) whose boundaries were dependent on the strain rate. From the observed property, we conclude that the deformation in the low temperature range is controlled by the Peierls mechanism, in the intermediate temperature range by the dynamic strain aging and in the high temperature range by the solute atmosphere dragging mechanism. The work softening tends to become less evident with an increasing experimental temperature and with a decreasing strain rate. The temperature and strain rate dependence of the critical resolved shear stress is the strongest in the high temperature range. The curves are divided into three parts with different slopes by a transition temperature. The critical resolved shear stress (${\tau}_{0.2}$) at the high temperature range showed that Mo content dependence of ${\tau}_{0.2}$ with temperature and the dependence is very marked at lower temperature. In the higher temperature range, ${\tau}_{0.2}$ increases monotonously with an increasing Mo content.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.3
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• pp.9-16
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• 2016

An experimental study was performed to investigate the combustion characteristics of the liquid hydrocarbon fuel atomized by an ultrasonic oscillator. Configuration of the flame was caught by the high-speed camera, and images were analyzed in detail through a post-processing. In addition, the fuel consumption was measured using the balance during the combustion reaction. As a result, the consumption of atomized fuel increased with the increasing flow-rate of carrier-gas, but any correlation between the air/fuel ratio and carrier-gas flow-rate was not found. The variation of flame area was dependent on the fuel consumption and input power of the ultrasonic oscillator. FFT (Fast Fourier Transform) analyses using the flame area were conducted in order to discuss flame flickering.

• Journal of the Korean Ceramic Society
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• v.46 no.1
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• pp.86-93
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• 2009

The crack formation and the resistance of ITO film on PET substrate with a thickness of 20 nm were investigated as a function of strain. The onset strain for the increase of resistance increased with increasing strain rate, suggesting the crack initiation is dependent on the strain rate. Electrical resistance increased at the strain of 1.6% at the strain rates below $10^{-4}/sec$ while it increased at ${\sim}2%$ at the strain rates above $10^{-3}/sec$. The critical strain at which the cracks were formed is close to the proportional limit. Upon loading, the initial cracks perpendicular to the tensile axis were observed and propagated the whole sample width with increasing strain. The spacing between horizontal cracks is thought to be determined by the fracture strength and the interfacial strength between ITO and PET. The crack density increased with increasing strain. However, the effect of the strain rate on the crack density was less pronounced in ITO/PET with 20 nm ITO thickness than ITO/PET with 125 nm ITO thickness, the strength of ITO film is thought to increase as the thickness on ITO film decreases. The absence of cracks on ITO film at a strain as close as 1.5% can be attributed to the compressive residual stress of ITO film which was developed during cooling after the coating process. The higher critical strain for the onset of the resistance increase and the crack initiation of ITO/PET with a thinner ITO film (20 nm) can be linked with the higher strength of the thinner ITO film.