• Carbon letters
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• v.14 no.4
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• pp.197-205
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• 2013

Five vapor-grown carbon nanofiber (VGCNF) reinforced vinyl ester (VE) nanocomposite configurations were fabricated, imaged, and mechanically tested in order to obtain information on the influence and the interactions of the role of the microstructure at lower length scales on the observed continuum level properties/response. Three independent variables (the nanofiber weight fraction and two types of nanofiber mixing techniques) were chosen to be varied from low, middle, and high values at equally spaced intervals. Multiple mixing techniques were studied to gain insight into the effect of mixing on the VGCNF dispersion within the VE matrix. The point count method was used for both lower length-scale imaging techniques to provide quantitative approximations of the magnitude and the distribution of such lower length-scale features. Finally, an inverse relationship was shown to exist between the stiffness and strength properties of the resulting nanocomposites under uniaxial quasistatic compression loading.

• Journal of the Korean Home Economics Association
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• v.35 no.2
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• pp.333-344
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• 1997

The purpose of this study was to investigate new method to incorporate demographic variables into demand models through modifying the theory in an attempt to capture interactions between individuals within a household. The method which utilizes household equivalence scale was very attractive in the sense that it provide less restrictive implications for the behavior model, and thus, the estimated expenditure elasticities might be more realistic because demographic variables are more elaborately controlled. the household equivalence scaled was developed using Lagrange Interpolation Polynomials. Then the empirical model with household equivalence scale was derived based on the model of Deaton and Muellbauer. For its empirical utilization, Consumer Expenditure survey(CES) conducted by the bureau of Labor Statistics(BLS) was used.

• Korean Journal of Child Studies
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• v.21 no.1
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• pp.141-161
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• 2000

This study examined the conditions and administration of 548 private, social welfare, and elementary school-based facilities providing after-school child care. The School-Age Care Environment Rating Scale developed by authors was administered to the teachers of these facilities. The rating scale consists of 84 items in 9 sub-areas. Seven point ratings were obtained for each item. One-way ANOVA confirmed differences between all items at the (p<.001) except for supplementary special needs items. The private facilities had the best environment for after-school child care except for staff development. The social welfare facilities showed good evaluation in staff-child interactions, activities, staff development and administration. The elementary schools obtained low evaluations except for supplementary special needs items. The evaluation of social welfare facilities was highest in Seoul and private child care facilities were highest in other areas.

• Wind and Structures
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• v.3 no.2
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• pp.97-115
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• 2000

The technique of proper orthogonal decomposition is potentially useful in specifying the fluctuating surface pressure field around structures. However there has been a degree of controversy over whether or not the calculated modes have physical meanings. This paper addresses this issue through consideration of the results of full scale experiments, and through an analytical investigation. It is concluded that the lower, most energetic modes are likely to reflect different fluctuating flow mechanisms, although no mode is likely to be associated with just one flow mechanism or vice versa. The higher, less energetic modes are likely to represent interactions between different flow mechanisms, and to be significantly affected by the number of measurement points and measurement errors. The paper concludes with a brief description of the application of POD to the problem of building ventilation, and the calculation of cladding pressures.

• Journal of Magnetics
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• v.10 no.3
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• pp.113-117
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• 2005

Some polycrystalline ferromagnetic mms are composed of continuously connected nanometer scale islands with random crystallite orientations. The nanometer perturbations of the mm introduce a large number of nearly degenerate local field configurations that are indistiguishable on a macroscopic scale. As a first step, this situation is modelled as a thin ferromagnetic disc coupled by exchange and dipole interactions to a homogeneous ferromagnetic plane, where the disc and plane have different easy axes. The model is solved to find the partial $N\acute{e}el$ domain walls that minimize the magnetic energy. The two solutions give a bistable configuration that, for appropriate geometries, provides an important microsopic ferromagnetic degree of freedom for the mm. These results are used to interpret recent measurements of exchange biased bilayer films.

• Structural Engineering and Mechanics
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• v.71 no.1
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• pp.89-98
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• 2019

In this study, the mechanical bending behaviors of functionally graded porous nanobeams are investigated. Four types of porosity which are, the classical power porosity function, the symmetric with mid-plane cosine function, bottom surface distribution and top surface distribution are proposed in analysis of nanobeam for the first time. A comparison between four types of porosity are illustrated. The effect of nano-scale is described by the differential nonlocal continuum theory of Eringen by adding the length scale into the constitutive equations as a material parameter comprising information about nanoscopic forces and its interactions. The graded material is designated by a power function through the thickness of nanobeam. The beam is simply-supported and is assumed to be thin, and hence, the kinematic assumptions of Euler-Bernoulli beam theory are held. The mathematical model is solved numerically using the finite element method. Numerical results show effects of porosity type, material graduation, and nanoscale parameters on the static deflection of nanobeam.

• Publications of The Korean Astronomical Society
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• v.27 no.4
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• pp.243-248
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• 2012

Nearby spiral galaxies M101 and M81 are considered to have undergone a galaxy-galaxy interaction. M101 has experienced HI gas infall due to the interaction. With AKARI far-infrared (IR) photometric observations, we found regions with enhanced star forming activity, which are spatially close to regions affected by the interaction. In addition, the relation between the star formation rate (SFR) and the gas content for such regions shows a significant difference from typical spiral arm regions. We discuss possible explanations for star formation processes on a kiloparsec scale and the association with interaction-triggered star formation. We also observed the compact group of galaxies Stephan's Quintet (SQ) with the AKARI Far-infrared Surveyor (FIS). The SQ shows diffuse intergalactic medium (IGM) due to multiple collisions between the member galaxies and the IGM. The intruder galaxy NGC 7318b is currently colliding with the IGM and causes a large-scale shock. The 160 micron image clearly shows the structure along the shock ridge as seen in warm molecular hydrogen line emission and X-ray emission. The far-IR emission from the shocked region comes from the luminous [CII]$158{\mu}m$ line and cold dust (~ 20 K) that coexist with molecular hydrogen gas. Survival of dust grains is indispensable to form molecular hydrogen gas within the collision age (~ 5 Myr). At the stage of the dusty IGM environment, [CII] and $H_2$ lines rather than X-ray emission are powerful cooling channels to release the collision energy.

• Journal of the Korea Convergence Society
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• v.10 no.1
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• pp.353-360
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• 2019

Purpose: The depression of the elderly in recent years has been increasing every year due to the remarkable change of the psychological function, which has a great influence on the life. Depression which is a powerful predictor of suicide in elderly people, causes various psychological and social problems. In this study, we try to understand convergently about the adaptation experiences of the depressed elderly with suicidal ideation. Procedures and Methods: Seven elderly people with a GDS(Geriatric Depression Scale) score of ${\geq}17$ and a SSI(Scale for Suicidal Ideation) score of ${\geq}9$ in the self-help group were interviewed until theoretical saturation. Data were analyzed based on the Grounded theory method. Results and Contribution: Depressed elderly recognized the importance of being the center of their lives through interactions with peer groups and they started to embrace their lives. Further studies: Empirical studies on positive interactions with peer groups affecting the adjustment experience of depressed elderly should be expanded and continued.

• The Journal of the Convergence on Culture Technology
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• v.9 no.1
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• pp.169-174
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• 2023

The purpose of this study is to analyze Korean college students' perceptions of interactions and senses of community, among students, and instructors and students as they took face-to-face classes by the time students and instructors came back to the classroom. Forty-nine college students participated in the study, and all of them had experienced non-face-to-face classes during the last two years from 2020 through 2021. They responded to the revised Rovai (2002)'s Classroom Community Scale (CCS), and the data were analyzed using a frequency analysis. The findings of data analysis showed that the students positively perceived the class contents and teaching formats of face-to-face classes, in terms of understanding and concentration on the class. On the other hand, it was found out that the students would still need more time for being familiar with face-to-face classes, and their affective variables of the educational environment should be considered.

• Genomics & Informatics
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• v.21 no.2
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• pp.19.1-19.13
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• 2023

Liver cancer, particularly hepatocellular carcinoma (HCC), poses a significant global threat to human lives. To advance the development of innovative diagnostic and treatment approaches, it is essential to examine the hidden features of HCC, particularly its 3D genome architecture, which is not well understood. In this study, we investigated the 3D genome organization of four HCC cell lines-Hep3B, Huh1, Huh7, and SNU449-using in situ Hi-C and assay for transposase-accessible chromatin sequencing. Our findings revealed that HCC cell lines had more long-range interactions, both intra-and interchromosomal, compared to human mammary epithelial cells (HMECs). Unexpectedly, HCC cell lines displayed cell line-specific compartmental modifications at the megabase (Mb) scale, which could potentially be leveraged in determining HCC subtypes. At the sub-Mb scale, we observed decreases in intra-TAD (topologically associated domain) interactions and chromatin loops in HCC cell lines compared to HMECs. Lastly, we discovered a correlation between gene expression and the 3D chromatin architecture of SLC8A1, which encodes a sodium-calcium antiporter whose modulation is known to induce apoptosis by comparison between HCC cell lines and HMECs. Our findings suggest that HCC cell lines have a distinct 3D genome organization that is different from those of normal and other cancer cells based on the analysis of compartments, TADs, and chromatin loops. Overall, we take this as evidence that genome organization plays a crucial role in cancer phenotype determination. Further exploration of epigenetics in HCC will help us to better understand specific gene regulation mechanisms and uncover novel targets for cancer treatment.