• Nuclear Engineering and Technology
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• v.54 no.4
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• pp.1464-1470
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• 2022

This paper presents a high performance burnable absorber named as CIMBA (Cylindrically Inserted and Mechanically Separated Burnable Absorber) for the soluble-boron-free SMR. The CIMBA is the cylindrical gadolinia inserted into the annular fuel pellets. Although the CIMBA utilizes the spatial self-shielding effect of the fuel material, a large reactivity upswing occurs when the gadolinia is depleted. To minimize the reactivity swing of the CIMBA-loaded FA, two approaches were investigated. One is controlling the spatial self-shielding effect of the CIMBA as burnup proceeds by a multi-layered structure of the CIMBA (ML-CIMBA) and the other is the mixed-loading of two different types of CIMBA (MIX-CIMBA). Both approaches show promising performances to minimize the reactivity swing, where the MIX-CIMBA is more preferable due to its simpler fabrication process. In conclusion, the MIX-CIMBA is expected to accelerate the commercialization of the CIMBA and can be used to achieve an optimal soluble-boron-free SMR core design.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.21 no.2
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• pp.55-59
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• 2011

Mong Hsu rubies from Myanmar include typically the dark core and blue patch but most of the previous research has merely focused on the dark core. This work is aimed to understanding clearly the characteristic of the dark core and blue patch of Mong Hsu rubies. It was found from the FTIR analysis that the dark core and blue patch region showed the absorption peaks of boehmite ($1986\;cm^{-1}$), diaspore ($2115\;cm^{-1}$) and water ($3400{\sim}3900\;cm^{-1}$) but the absorption peaks of O-H stretching ($3309\;cm^{-1}$ and $3078\;cm^{-1}$) were found only in blue patch region. The UV-VIS-NIR analysis of the dark core region revealed the stronger absorption of $Cr^{3+}$ at 405 and 554 nm compared to the blue patch region. In range of 600~800 nm, the UV absorption characteristic at 659, 675 and 693 nm assigned to $Cr^{3+}$ of core group samples is distinct from that of blue patch. The SEM-EDS examinations disclosed the existence of lots of micro-cracks and pores in the core regions compared to blue patch region.

• Journal of Korean Medicine Rehabilitation
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• v.19 no.3
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• pp.69-80
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• 2009

Objectives : The purpose of this study was to evaluate the effects of core stability training on postural control and balance of hemiplegia patients who are difficult to control posture due to stroke. Methods : Subjects of the study were consisted of 25 adult hemiplegia patients(experimental 12, control 13) who were receiving rehabilitation therapy in hospital. Its group had a core stability training program by a physical therapists for 40 minutes, five times a week for nine-week period. Measurements of postural assessment scale for stroke(PASS), berg balance scale(BBS) and manual function test(MFT) were evaluated at initial presentation(pretest) and after completion of the each therapy program(posttest). Independent t-test and paired t-test was utilized to detect the mean difference between the groups. Results : Firstly, the result of PASS showed that postural control was significantly increased after the completion of core stability training(p<.01). Secondly, the result of BBS showed that balance control was significantly increased after the completion of core stability training(p<.01) and general physical therapy(p<.01). Lastly, the result of MFT showed that upper extremity's motor function was significantly increased after the completion of core stability training(p<.001). Conclusions : This study showed that core stability training is an effective treatment strategy on postural control, balance and upper extremity's motor function.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.11
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• pp.116-123
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• 2009

The elastic properties of core affect mechanical properties and deformation behaviours of the lightweight sandwich panel. The objective of the present paper is to estimate experimentally Young's and shear moduli of a core in internally structured boned (ISB) panel with woven metal as inner structures using the deflection theory of sandwich beam considered core stiffness. Three points bending experiments were performed to obtain force-deflection curves of the designed ISB panel in each material direction. The elastic and shear moduli of the core in each material direction were estimated from slopes and intercepts of relationships between compliance per the span length and square of the span length, respectively. The results of the estimation showed that the fabric technology of the woven metal affects the variation of the elastic properties in the core. Through the comparison of shear moduli and force-deflection curves of the proposed method and those without considering the core stiffness, it was shown that the core stiffness should be considered to estimate properly the Young's and shear moduli of ISB panels. Finally, the contribution ratio of bending and shear deflections of ISB panels to the total deflection was quantitatively examined.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.4
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• pp.409-419
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• 2008

Statement of problem: At all times people have tried to fabricate tooth restorations using tooth colored materials. Recently, demands for esthetics, even in restorations requiring strength, has brought a revolution to dentistry and increased use of zirconia. The basic color of zirconia is white to ivory. The color can be partially adapted by veneering it with ceramic materials. However, it would be better if the substructure could already be adapted to the basic color shade of neighboring teeth. By adaptation to the basic shade, it can help to reduce the necessary layer thickness of the veneer ceramic to achieve the desired color. Purpose: The purpose of this study was to spectrophotometrically evaluate the influence of shading of zirconia core on the final shade of all-ceramic restorations using the CIE $L^{*}a^{*}b^{*}$ system. Material and methods: Core specimens (n = 20 per group) of Lava Frame Zirconia, KaVo Everest Zirconia, Digident CAD/CAM Zirconia were fabricated at 20 mm in diameter and 0.5 mm in thickness. Halves of each groups were shaded in A3 color. These core specimens were veneered with A3 porcelain of the recommended manufacturer at thickness of 0.5 mm. CIE $L^{*}a^{*}b^{*}$ coordinates were recorded for each specimen with a spectrophotometer (Model CM-2600d, Minolta, Japan) at 0.5 mm, 0.4 mm, 0.3 mm in thickness. Color differences were calculated using the equation ${\Delta}E^{*}=[({\Delta}L^{*})2+({\Delta}a^{*})2+({\Delta}b^{*})2]1/2$. Results: 1. In the case where porcelain layer has a thickness of 0.5 mm, Lava Frame Zirconia and KaVo Everest group did not show clinically perceived color difference, however Digident CAD/CAM Zirconia group showed clinically perceived color difference according to shade allowed on core. 2. When the thickness of porcelain layer decreased from 0.5 mm to 0.4 mm, Lava Frame Zirconia and KaVo Everest group did not show clinically perceived color difference, on the other hand Digident CAD/CAM Zirconia group showed clinically perceived color difference according to shade allowed on core. 3. When the thickness of porcelain layer decreased from 0.5 mm to 0.3 mm, clinically perceived color differences were observed from all three groups. Conclusions: Ziroconia system, which is possible to allow shade on core, are thought to be much more favorable to reproduce natural shade compared to systems that is impossible to give shade. Therefore, clinicians ought to choose adequate system for certain clinical situation by considering above specific character.

• Korean Journal of Microbiology
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• v.51 no.4
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• pp.329-337
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• 2015

All known genomes (N=10) in the order Nitrosomonadales were analyzed to contain 9,808 and 908 gene clusters in their pan-genome and core genome, respectively. Analyses with reference genomes belonging to other orders in Betaproteobacteria revealed that sizes of pan-genome and core genome were dependent on the number of genomes compared and the differences of genomes within a group. The sizes of pan-genomes of the genera Nitrosomonas and Nitrosospira were 7,180 and 4,586 and core genomes, 1,092 and 1,600, respectively, which implied that similarity of genomes in Nitrosospira were higher than Nitrosomonas. The genomes of Nitrosomonas contributed mostly to the size of the pan-genome and core genomes of Nitrosomonadales. COG analysis of gene clusters showed that the J (translation, ribosomal structure and biogenesis) category occupied the biggest proportions (9.7-21.0%) among COG categories in core genomes and its proportion increased in the group which genetic distances among members were high. The unclassified category (-) occupied very high proportions (34-51%) in pan-genomes. Ninety seven gene clusters existed only in Nitrosomonadales and not in reference genomes. The gene clusters contained ammonia monooxygenase (amoA and amoB) and -related genes (amoE and amoD) which were typical genes characterizing the order Nitrosomonadales while they contained significant amount (16-45%) of unclassified genes. Thus, these exclusively-conserved gene clusters might play an important role to reveal genetic specificity of the order Nitrosomonadales.

• Journal of The Korean Association For Science Education
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• v.36 no.6
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• pp.835-849
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• 2016

The purpose of the present study is to analyze the trajectory of science core school students' STEM career motivation and to examine the relationship between the trajectory patterns and students' tracks. Longitudinal STEM career motivation data with seven constructs were collected from 256 students for five semesters and the data were analyzed by using group-based trajectory modelling analysis. In order to examine the relationship between trajectory pattern groups and the tracks, chi-square tests were conducted. Based on our findings, we found that students are likely to have similar trajectory patterns in STEM career education experience and in their perception towards STEM career value. In terms of parents' support, academic self-efficacy and STEM career motivation aspects are divided into two distinctive trajectory groups ('high' and 'low' group), while two other variables, STEM career self-efficacy and STEM career interest, are divided into three trajectory groups ('moderate declining', 'high declining', 'increasing' group). Most of the trajectory groups are shown the pattern that the level of each constructs increase until their second academic year, then after that, the patterns started going down. Moreover, there are significant relationship between track and each trajectory groups. Science track and science-core track students have similar trajectory patterns. In contrast, humanities track students have different trajectory groups in some constructs. Based on these findings, we suggest that STEM career education environment should consider various patterns of students' STEM career development.

• Journal of The Korean Association For Science Education
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• v.39 no.6
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• pp.799-807
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• 2019

The study was conducted to identify if the first-year program of science-focused school improved students' scientific core competency and science learning motivation. The first-year program of the science-focused school consisted of basic education in scientific inquiry, investigation, advanced experiment, and basic education in small research. There were a total of 262 participants in the program, and 169 students took three survey tests. Through the analysis of a group-based trajectory modeling, students were differentiated based on similarity of score changes. This study showed that the first-year program of the science-focused school significantly improved students' scientific core competency and science learning motivation. A group-based trajectory modeling found that about 40~60% of students saw the effects of the program. The students who chose the humanity track showed effects, while some students who chose the science-focused track did not show effects. A group-based trajectory modeling showed the methodological effects of identifying the change process of individual students. This study identified the positive effects of science-focused school policy statistically and is a meaningful example for analyzing the effectiveness of science-focused school programs.

• Korean Journal of Medicinal Crop Science
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• v.18 no.4
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• pp.224-230
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• 2010

This study was conducted to investigate anti-oxidative and inflammatory inhibition effects of green tea and dietary fiber mixture on liver of high fat diet-induced obese rats. 21 male rats were divided into 3 dietary groups and control group (A), high fat diet-induced group (B), and high fat (HF) diet-induced + EQ diet-$S^{(R)}$ diet group (C). Immunoblotting and RT-PCR analysis revealed protein expression, and anti-oxidant analysis revealed MDA (malondialdehyde), GSH (glutathione), and free DPPH radical. As a results, Body weight and food consumption were not significantly different between groups. The levels of MDA and GSH were lower in HF + $EQS^{(R)}$ group than in HF group. Also, the $EQS^{(R)}$ demonstrated to be more effective than HF group for a DPPH radicals scavenging activities. In addition, protein and mRNA level of TNF-$\alpha$ in HF + $EQS^{(R)}$ group showed relatively more potent pro-inflammatory activity inhibition compared to HF group. These results suggest that green tea mixture (EQ diet-$S^{(R)}$) provide positive effects on anti-oxidative and inflammatory inhibition effects on obese animal model or obesity related diseases.

• Spatial Information Research
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• v.16 no.4
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• pp.385-400
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• 2008

This study investigates how Korean Land Spatialization Group (KLSG) has controlled and managed its own R&D effectively and what particular elements have made it practical. Korean Land Spatialization Program (KLSP) has produced large amounts of practical outcomes for the intelligent land by collaborative 5 core research projects. The well-harmonized cooperations between proving ground, practical business model, and services oriented integration and others have driven the KLSG to an succeedable management. The active role for practicality is prominent with its usefulness and competitiveness. KLSP is financially and administratively supported from Ministry of Land Transport and Maritime Affairs of Korea (MLTM). By investigating relationships between 5 core research projects involved in the R&D projects of KLSG, it has been found out that R&D projects of KLSG bring forth practicality and commercialization. The results of this study presents strategies of KLSP in conducting research for practicality and commercialization of GIS technology and integrated geospatial information.