• Bulletin of the Korean Chemical Society
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• v.18 no.9
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• pp.976-981
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• 1997

The magnetic susceptibilities of molybdenum ions with 4d1 electronic configuration in the octahedral crystal field were calculated on the basis of ligand field theory. The experimental magnetic susceptibilities for molybdenum ions, which are stabilized at the octahedral site in the perovskite lattice of Ba2ScMoⅤO6 and Sr2YMoⅤO6, were compared with the theoretical ones. We have tried to fit their temperature dependence of magnetic susceptibility with ligand field parameters, spin-orbit coupling constant ζSO, and orbital reduction parameter κ according to intermediate field coupling and strong field theory. Strong field coupling theory could not explain experimental curves without unrealistically large axial ligand field, since it ignores the mixing up between different state via spin-orbit interaction and ligand field. On the other hand, the intermediate field coupling theory could successfully reproduce experimental data in octahedral and trigonal ligand field. The fitting result demonstrates not only the fact that spin-orbit interaction is primarily responsible for the variation of magnetic behavior but also the fact that effective orbital overlap, enhanced by cubic crystal structure, reduces significantly orbital angular momentum as indicated by κ parameter.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.33.1-33.1
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• 2018

The differential rotational properties of early-type galaxies (ETGs) revealed by integral field spectroscopy surveys is arguably one of the most exciting findings in the galaxy evolution study during the past decade. Numerical studies have shown that galaxy mergers under various configurations can reproduce the observed distribution of ETG spin. However, we suggest an alternative scenario for the spin evolution of a large fraction of ETGs. Using the Horizon-AGN simulation, we follow the spin evolution of 10037 color-selected ETGs more massive than 1010 Msun that are divided into four groups: cluster centrals (3%), cluster satellites (33%), group centrals(5%), and field ETGs (59%). We find a strong mass dependence of the slow rotator fraction, fSR, and the mean spin of massive ETGs. Although the environmental dependence is not clear in the fSR, it is visible in the mean value of the spin parameter. The environmental dependence is driven by the satellite ETGs whose spin gradually decreases as their environment becomes denser. Galaxy mergers appear to be the main cause of total spin changes in 94% of central ETGs of halos with Mvir > 1012.5 Msun, but only 22% of satellite and field ETGs. We find that non-merger induced tidal perturbations better correlate with the galaxy spin-down in satellite ETGs than mergers. Given that the majority of ETGs are not central in dense environments, we conclude that non-merger tidal perturbation effects played a key role in the spin evolution of ETGs observed in the local (z < 1) universe.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.413-415
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• 2015

How galaxy evolution differs in different environments is one of the intriguing questions in the study of structure formation. While galaxy properties are clearly distinguished in different environments in the local universe, it is still an open issue what causes this environmental dependence of various galaxy properties. To address this question, in this work, we investigate the build-up of passive galaxies over a wide redshift range, from z ~ 2 to z ~ 0.5, focusing on its dependence on galaxy environment. In the UKIDSS/Ultra Deep Survey (UDS) field, we identify high-redshift galaxy cluster candidates within this redshift range. Then, using deep optical and near-infrared data from Subaru and UKIRT available in this field, we analyze and compare the stellar population properties of galaxies in the clusters and in the field. Our results show that the environmental effect on galaxy star-formation properties is a strong function of redshift as well as stellar mass - in the sense that (1) the effect becomes significant at small redshift, and (2) it is stronger for low-mass ($M_{\ast}<10^{10}M_{\odot}$) galaxies. We have also found that galaxy stellar mass plays a more significant role in determining their star-formation property - i.e., whether they are forming stars actively or not - than their environment throughout the redshift range.

• Journal of Aerospace System Engineering
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• v.16 no.2
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• pp.1-12
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• 2022

The purpose of this study was to investigate the supply and demand structure of the domestic space industry through analysis of industrial concentration index, by sector and dependence on revenue by customer type. As a result of industrial concentration analysis, in the case of space application, a supply monopoly or oligopoly structure was revealed in fields such as satellite broadcasting, space insurance, and satellite navigation. In the field of space equipment manufacturing, referred to as the traditional space industry, a supply monopoly structure appeared only in the field of launch pads and test facilities. As a result of analyzing the dependence on revenue by customer type, the dependence on the demand in the space application field is diversified among foreign countries, private institutions, and others. However, in the case of space equipment manufacturing, it is highly dependent on the demand of public institutions, and it seems that there is a monopsony structure.

• Journal of The Korean Association For Science Education
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• v.28 no.6
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• pp.675-684
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• 2008

This study investigated the effects of the prescribed instructional strategy for reducing students' connecting errors in learning chemistry concepts with multiple external representations by students' field independence-dependence. Seventh graders (N=126) at a coed middle school were assigned to control and treatment groups. The students learned "Boyle's Law" and "Charles's Law" for two class periods. Results revealed that the students in the treatment group scored significantly higher than those in the control group in a conception test. The scores of the treatment group were significantly higher than those of the control group in a motivational learning test, especially in 'attention' of the test. However, there was no significant interaction between the instruction and students' field independence-dependence in the two tests. Most students in the treatment group perceived the instruction positively in cognitive and motivational aspects.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.10
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• pp.620-624
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• 2016

Ferroelectric $Pb(Zr_{0.52}Ti_{0.48})O_3$ (PZT) films were deposited on SrTiO3(100) substrate by using conductive $SrRuO_3$ films as underlayer and their structural and ferroelectric properties were investigated. PZT films were grown in (00l) orientation on well lattice-matched pseudo-cubic $SrRuO_3$ films. Thickness dependence of ferroelectric and electrical properties of PZT films was investigated. PZT film with 400 nm thickness showed a remanent polarization ($P_r$) of $29.0{\mu}C/cm^2$ and coercive field ($E_c$) of 83 kV/cm, and $P_r$ decreased and $E_c$ increased with thickness reduction. The dielectric constant for PZT films showed gradual decrease with thickness reduction. Breakdown field of PZT films did not show the thickness dependence and displayed as high value as 1 MV/cm.

• Progress in Superconductivity
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• v.8 no.2
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• pp.132-137
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• 2007

We have studied superconducting parameters of $MgB_2$ single crystals from reversible magnetization measurements with the magnetic field both parallel and perpendicular to the c-axis of the crystals. The temperature dependence of the London penetration depth, ${\lambda}_{ab}{^{-2}}(T)$, obtained from the Hao-Clem analysis on reversible magnetization, shows a clear discrepancy from single-band theories. It is also found that the anisotropies of the London penetration depth, ${\gamma}_{\lambda}$, slowly increases with temperature while the anisotropy of the upper critical field, ${\gamma}_H$, decreases with temperature. These behaviors are in sharp contrast with the behavior of superconductors with a single band. The temperature dependence of ${\lambda}_{ab}{^{-2}}$, and the opposite temperature dependences of ${\gamma}_{\lambda}\;and\;{\gamma}_H$ can be well explained with the theory of the two-band superconductivity.

• Journal of Magnetics
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• v.22 no.2
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• pp.188-195
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• 2017

The ferromagnetic resonance and other magnetic properties dependence on $Ni^{2+}/Fe^{3+}$ ratio and crystallite size were investigated for nano nickel ferrite ($NiFe_2O_4$). The crystallite size was controlled by controlling the nickel content in the starting material solution. The XRD and TEM were utilized to measure the crystallite size through Scherrer formula and particle size respectively. The most frequent particle sizes were lower than crystallite size, which ranged from 16.5 to 44.65 nm. The general behavior of M-H loop shapes and parameters showed superparamagnetic one. The saturation magnetization had a maximum value at $Ni^{2+}/Fe^{3+}$ molar ratio equal to 0.186. The FMR signals showed, generally, broad linewidths, where the maximum width and minimum resonance field were for the sample of the lowest crystalline size. Furthermore, FMR resonance field shows linear dependence on crystalline size. The fitting relation was estimated to express this linear dependency on the base of behavior coincidence between particle size and the inverse of saturation magnetization. The given interpretations to understand the intercept and the slope meanings of the fitted relation were based on Larmor equation, and inhomogeneous in the anisotropy constant.

• Transactions on Electrical and Electronic Materials
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• v.3 no.3
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• pp.34-38
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• 2002

In this paper, efficiency estimation of toxicity fee fire resistance cable experiments was measured smoke density of toxicity free fire resistance polyolefin insulation material and electric field dependence of tree shape in low density polyethylene (LDPE). One of the most serious causes of failure in high-voltage cables, can be an electrical discharge across an internal gab or void in the insulating material. Treeing due to partial discharge is one of the main causes of breakdown in the insulating materials and reduction of the insulation life. Therefore the necessity for establishing a method to diagnose the aging of insulation materials and to predict the breakdown of insulation and research of the fire resistance character has become important. First, we have studied on electric field dependence of tree shape in LDPE about treeing phenomena occurring on the high electrical field. Second, the measurement method is the attenuation quantity of irradiation by smoke accumulating with in a closed chamber due to non-flaming heat decomposition and flaming combustion. A main cause of fire-growth and generating toxic gas when, it bums, should be dealt with great care in life. safety design. The fire gases were occurred carbon monoxide and decomposition than in polyolefin due to incomplete combustion of PVC, which has high content of carbon in chemical compound.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.9
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• pp.3204-3220
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• 2021

We perform the task of video object segmentation by incorporating a conditional random field (CRF) and convolutional neural networks (CNNs). Most methods employ a CRF to refine a coarse output from fully convolutional networks. Others treat the inference process of the CRF as a recurrent neural network and then combine CNNs and the CRF into an end-to-end model for video object segmentation. In contrast to these methods, we propose a novel higher-order CRF model to solve the problem of video object segmentation. Specifically, we use CNNs to establish a higher-order dependence among pixels, and this dependence can provide critical global information for a segmentation model to enhance the global consistency of segmentation. In general, the optimization of the higher-order energy is extremely difficult. To make the problem tractable, we decompose the higher-order energy into two parts by utilizing auxiliary variables and then solve it by using an iterative process. We conduct quantitative and qualitative analyses on multiple datasets, and the proposed method achieves competitive results.