• Journal of Conservation Science
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• v.35 no.3
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• pp.237-244
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• 2019

In this study, we applied terahertz imaging technology to three Korean modern oil paintings ('Boy,' 'Girl,' and 'Hyehwadong Landscape'); investigated the types of inner layer information in the pictures that can be extracted with terahertz imaging technology; and analyzed the conditions for extracting them. The biggest problem in the terahertz imaging analysis we encountered was the image distortion caused by the change of the distance between the target surface and the terahertz detector, depending on the surface curvature of the target paintings. We then developed a 'working distance maintaining device' to solve this problem. As a result, the terahertz imaging technique was used to identify the base material characteristics and any patterns of damage inside, and presented the optimal conditions for identifying each characteristic. In addition, it was useful to employ the terahertz frequency-division image to check the characteristics of the background materials. To confirm coloring techniques such as brush strokes, it is effective to compare the maximum reflection peak image with the cross-section image; and to detect damage information inside the paintings that cannot be observed on the surface, to compare the cross-section image with the frequency-division image. On the other hand, according to the terahertz imaging analysis of the oil paintings, the internal structural damage marks of 'Boy' and 'Girl' were confirmed, and the artist's painting style was confirmed in 'Hyehwadong Landscape.' The above results are expected to be useful for the analysis and diagnosis of Korean modern oil paintings for their preservation.

• Journal of the Korean Applied Science and Technology
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• v.36 no.1
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• pp.312-323
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• 2019

This purpose of study was to influence of elementary school student's Judo gym training program on social development and life satisfaction. This study aims at providing fundamental data and information on Judo participants by studying what effects of training program characteristic on social development and life satisfaction. The survey was done through 300 copies and excluding 15 copies ran an analysis on the remaining 285(90%) copies. After question investigating the data which is collected used IBM SPSS statistics 21 and IBM AMOS 21 program, frequency analysis, Exploratory factor analysis and confirmatory factor analysis, convergent validity, discriminant validity, Cronbach's ${\alpha}$, correlation analysis, path analysis through Structural Equation Model(SEM), mediation effect analysis by Sobel test. The result of this study were as follows. First, elementary school student's Judo gym training program showed (+) effects on social development. Second, elementary school student's Judo gym training program had no effects on life satisfaction. Third, social development showed (+) effects on life satisfaction. Forth, social development showed complete mediation effect on elementary school student's Judo gym training program and life satisfaction.

• The Korean Journal of Archival Studies
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• no.46
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• pp.45-93
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• 2015

Art Museum Archives are archives that are created by individuals and organizations that have a sufficient worth that necessitate permanent preservation. Art Museum Archives, which include various medium and types, are archives that have information and evidence based value, and are established and supported for the research of the Art Museum and Art History. For the systematic implementation and application of an Art Museum Archive, there is a need to establish related description elements, and through this not only must information on the individual archives be provided, but through a high utility finding aid, the creation context of the archived document should be provided so that users of the archive can easily access documents. In the case of Korean Art Museum Archives, there is a tendency to focus on the fragmented informational value of an individual archive document, which in reality causes the structural and contextual element characteristic of the document to be destroyed. Therefore this research supports the Hierarchical Description of Art Museum Archives and has the objective of proposing Art Archive Description Elements that promote the preservation of creation context and effective utilization. In addition, because personal records take up a large portion of Art Archives and are very diverse in terms of medium and type, a Description Element that can reflect this is attempted to be proposed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.613-618
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• 2019

The flow-induced vibration in a heat exchanger may cause the damage to piping. Therefore, it is necessary to establish the flow induced vibration characteristics for the structural stability of a heat exchanger. The purpose of this study was to compare the generation, development, and separation characteristics of a vortex around a circular tube with respect to time when the flow velocity of the inlet was fluctuating constantly and periodically. The time characteristics of lift and drag and the PSD characteristics were also investigated. In the case of a constant inlet flow velocity, the well-known Kalman vorticity distribution was shown. The vortex generation, growth, and separation were also observed alternately at the upper and lower sides of the tube. In the case of periodic inlet flow velocity, the vortex occurred simultaneously in the upper and lower sides of the tube. In the case of constant inlet flow velocity, the magnitude of the lift PSD was 500 times larger than that of drag. The frequency was 31.15 Hz and that of drag was doubled at 62.3 Hz. In case of a periodic inlet flow velocity, the PSD of the drag was approximately 500 times larger than that of lift. The frequency was 15.57 Hz, which was the same as the inlet-flow velocity frequency. In addition, the frequency of lift was 31.15 Hz, which was the same Karman vortex frequency.

• Investigative Magnetic Resonance Imaging
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• v.25 no.3
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• pp.164-171
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• 2021

Purpose: Mild cognitive impairment (MCI) is a prodromal stage of Alzheimer's disease (AD). Brain atrophy in this disease spectrum begins in the medial temporal lobe structure, which can be recognized by magnetic resonance imaging. To overcome the unsatisfactory inter-observer reliability of visual evaluation, quantitative brain volumetry has been developed and widely investigated for the diagnosis of MCI and AD. The aim of this study was to assess the prediction accuracy of quantitative brain volumetry using a fully automated segmentation software package, NeuroQuant^®, for the diagnosis of MCI. Materials and Methods: A total of 418 subjects from the Korean Brain Aging Study for Early Diagnosis and Prediction of Alzheimer's Disease cohort were included in our study. Each participant was allocated to either a cognitively normal old group (n = 285) or an MCI group (n = 133). Brain volumetric data were obtained from T1-weighted images using the NeuroQuant software package. Logistic regression and receiver operating characteristic (ROC) curve analyses were performed to investigate relevant brain regions and their prediction accuracies. Results: Multivariate logistic regression analysis revealed that normative percentiles of the hippocampus (P < 0.001), amygdala (P = 0.003), frontal lobe (P = 0.049), medial parietal lobe (P = 0.023), and third ventricle (P = 0.012) were independent predictive factors for MCI. In ROC analysis, normative percentiles of the hippocampus and amygdala showed fair accuracies in the diagnosis of MCI (area under the curve: 0.739 and 0.727, respectively). Conclusion: Normative percentiles of the hippocampus and amygdala provided by the fully automated segmentation software could be used for screening MCI with a reasonable post-processing time. This information might help us interpret structural MRI in patients with cognitive impairment.

• Applied Chemistry for Engineering
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• v.22 no.2
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• pp.133-137
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• 2011

In this study, illite was size-reduced using a wet-ball-milling treatment to improve its dispersion. Changes in illite particle size, size distribution, and dispersion characteristics after varying the treatment period were investigated. And the dispersion and dispersion stability of illite solution after 2 h wet ball milling treatment with different pH conditions were also evaluated. The illite particle size significantly decreased as the treatment time increased and the size reduction effect of wet ball milling deteriorated above 2 h treatment time. In addition, illite particle size was more evenly distributed as the treatment time increased. X-ray diffraction (XRD) analysis showed that no crystal structural changes of illite were induced, but the characteristic peak of illite the weaker due to the size reduction and exfoliation, as the treatment time increased. Zeta potential analysis showed that the illite dispersion improved, as the treatment time increased. The illite wet-ball-mill treated at pH 2 had the lowest dispersion stability. Illite dispersion and dispersion stability increased as pH increased, due to the increase in surface ionization. Hence, the results showed that as the treatment time increased, the illite particle size decreased, and dispersion and dispersion stability improved due to the increase in surface energy and repulsion force between particles.

• Korean journal of psychology:General
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• v.36 no.2
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• pp.241-270
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• 2017

In this study we investigated the structural relationship between the Big Five personality traits which is a pretrauma characteristic, posttraumatic cognition, rumination, posttraumatic growth(PTG), and posttraumatic stress disorder(PTSD) symptoms. The participants were 1,000 adults who experienced traumatic event. For statistical analysis we set the research model with the Big Five personality traits affecting deliberate rumination through posttraumatic cognition and intrusive rumination. Competing model was set without the path from intrusive rumination to deliberate rumination. The results indicated that rumination and posttraumatic cognition did not mediate the relationship between extraversion, agreeableness, conscientiousness and PTG, PTSD symptoms. Second, there was a mediating effect of intrusive rumination between openness to experience and PTSD symptoms. Moreover, the pathway to intrusive rumination, deliberate rumination, and PTG from openness to experience was also significant. Third, the pathway to posttraumatic cognition, event-related rumination, and both PTSD symptoms and PTG from neuroticism was significant. These results support the cognitive process of PTG model In the end we discussed the implication and limitations of the study.

• Korean Journal of Food Science and Technology
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• v.52 no.6
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• pp.595-603
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• 2020

To elucidate the structure-function relationship of polysaccharides obtained from Colocasia esculenta, the immuno-stimulating polysaccharide, CE-4a was purified to homogeneity from the crude polysaccharide (CE) extracted from the corms of C. esculenta by two subsequent column chromatographies using DEAE-Sepharose FF and Sephadex G-100, and analysis of their immuno-stimulatory activities and structure were conducted. CE-4a showed an increase in anti-complementary activity in a dose-dependent fashion. The molecular mass was estimated to be 182.4 kDa, which mainly consisted of galactose (43.5%) and mannose (18.2%). Methylation analysis indicated that CE-4a comprised at least 10 different glycosyl linkages, such as terminal Galp, 3-linked Galp, and 4-linked Manp, as well as a characteristic linkage, 2,4,6-branched Manp residue. To analyze the fine structure of CE-4a, it was sequentially digested using endo-α-(1→4)-polygalacturonase, exo-α-galactosidase and endo-β-1,4-D-mannanase. These analyses suggested that CE-4a is to be a highly branched galactomannan with a (1→4)-mannan backbone and galactopyranosyl oligosaccharide side chains.

• The Journal of the Convergence on Culture Technology
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• v.7 no.1
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• pp.17-23
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• 2021

Social media users are an important part of our lives as they spend a lot of time and actively use them. However, it is known that there are many users who feel the psychological stress of SNS stress or fall into addiction due to SNS use. SNS stress negatively affects not only the user's mind but also the body. This study investigates the associations between SNS stress and addiction. To test the hypotheses, the study performed structural equation modeling using Amos. We collected 210 data from SNS users. The empirical results showed that SNS overuse had a significant effect on SNS stress. Second, SNS stress had a significant relationship with SNS addiction. Third, it was found that SNS overuse did not directly affect SNS addiction. This study suggests that it is necessary to recognize the importance of the relationship between SNS addiction and SNS stress.

• Korean Journal of Heritage: History & Science
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• v.54 no.1
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• pp.32-51
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• 2021

Architectural evidence of Gaya is insignificant than any other area. In this situation, house-shaped earthenware is particularly helpful in the study of Gaya architecture. However, house-shaped earthenware is not a building, it has just the shape of buildings. So, we have to find out architectural evidence from that. In this paper, I tried to estimate the architectural characteristics of Gaya through house-shaped earthenware in detail. I also consulted historical records, archeological results, and other scholars' papers. The results are as follows. First, house-shaped earthenware can be classified into three types according to its shape, and each type has distinct architectural structural characteristics. Second, house-shaped earthenware generally has a gambrel roof, and the characteristic of architectural design with the gable side of the gambrel roof as a front is the biggest feature of Gaya architecture. Third, various types of buildings existed according to their functions in Gaya architecture, and house-shaped earthenware was showed buildings of ancient storage, pens, and residences, which are symbols of the richness among various types of buildings.