• Nuclear Engineering and Technology
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• v.47 no.6
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• pp.738-745
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• 2015

The catalytic exchange of hydrogen isotopes between hydrogen and water has been known to be a very useful process for the separation of tritium from tritiated water. For the process, a highly active hydrophobic catalyst is needed. This study provides an effective fabrication method of size-controlled platinum/poly[styrene-divinylbenzene-tri(propylene glycol) diacrylate] [Pt/poly(SDB-TPGDA)] hydrophobic catalyst beads with a narrow size distribution. Platinum nanoparticles were prepared by ${\gamma}$-ray-induced reduction in the aqueous phase first, and then uniformly dispersed in SDB-TPGDA comonomer after the hydrophobization of platinum nanoparticles with alkylamine stabilizers. The porous Pt/poly(SDB-TPGDA) hydrophobic catalyst beads were synthesized by the UV-initiated polymerization of the mixture droplets prepared in a capillary-based microfluidic system. The size of as-prepared catalyst beads can be controlled in the range of $200-1,000{\mu}m$ by adjusting the flow rate of dispersed and continuous phases, as well as the viscosity of the continuous phase. Sorbitan monooleate and cyclohexanol were used as coporogens to control the porosities of the catalyst beads.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.2
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• pp.1100-1123
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• 2019

A code-based cryptosystem can resist quantum-computing attacks. However, an original system based on the Goppa code has a large key size, which makes it unpractical in embedded devices with limited sources. Many special error-correcting codes have recently been developed to reduce the key size, and yet these systems are easily broken through side channel attacks, particularly differential power analysis (DPA) attacks, when they are applied to hardware devices. To address this problem, a higher-order masking scheme for a McEliece cryptosystem based on the quasi-dyadic moderate density parity check (QD-MDPC) code has been proposed. The proposed scheme has a small key size and is able to resist DPA attacks. In this paper, a novel McEliece cryptosystem based on the QD-MDPC code is demonstrated. The key size of this novel cryptosystem is reduced by 78 times, which meets the requirements of embedded devices. Further, based on the novel cryptosystem, a higher-order masking scheme was developed by constructing an extension Ishai-Sahai-Wagne (ISW) masking scheme. The authenticity and integrity analysis verify that the proposed scheme has higher security than conventional approaches. Finally, a side channel attack experiment was also conducted to verify that the novel masking system is able to defend against high-order DPA attacks on hardware devices. Based on the experimental validation, it can be concluded that the proposed higher-order masking scheme can be applied as an advanced protection solution for devices with limited resources.

• Korean Journal of Materials Research
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• v.31 no.3
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• pp.139-149
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• 2021

In this study, three kinds of bainitic steels are fabricated by controlling the contents of vanadium and boron. High vanadium steel has a lot of carbides and nitrides, and so, during the cooling process, acicular ferrite is well formed. Carbides and nitrides develop fine grains by inhibiting grain growth. As a result, the low temperature Charpy absorbed energy of high vanadium steel is higher than that of low vanadium steel. In boron added steel, boron segregates at the prior austenite grain boundary, so that acicular ferrite formation occurs well during the cooling process. However, the granular bainite packet size of the boron added steel is larger than that of high vanadium steel because boron cannot effectively suppress grain growth. Therefore, the low temperature Charpy absorbed energy of the boron added steel is lower than that of the low vanadium steel. HAZ (heat affected zone) microstructure formation affects not only vanadium and boron but also the prior austenite grain size. In the HAZ specimen having large prior austenite grain size, acicular ferrite is formed inside the austenite, and granular bainite, bainitic ferrite, and martensite are also formed in a complex, resulting in a mixed acicular ferrite region with a high volume fraction. On the other hand, in the HAZ specimen having small prior austenite grain size, the volume fraction of the mixed acicular ferrite region is low because granular bainite and bainitic ferrite are coarse due to the large number of prior austenite grain boundaries.

• Journal of Pharmacopuncture
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• v.24 no.4
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• pp.196-205
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• 2021

Objectives: Bruising is an important side effect of enoxaparin injection. Comfrey (Symphytum officinale) is used to treat different types of wounds, bone fractures, and bruising in traditional medicine in many countries for centuries. This study aimed to determine the effects of the Comfrey ointment on the bruise size and color following enoxaparin injection. Methods: This double-blind randomized clinical trial was conducted on 80 patients with acute coronary syndrome (ACS). The participants were randomly divided into two groups of 40, namely Comfrey and Placebo. Changes in bruise size and color in both groups were assessed daily before and after the intervention. Results: The Comfrey and Placebo groups were homogeneous in demographic and clinical variables. A downward trend was observed in the bruise size in both groups throughout the study. However, the bruise size was smaller in the Comfrey group than the Placebo group on day 2-5 of the intervention. Moreover, there was a significant difference in bruise color between the groups, with a shorter healing course in the Comfrey group. Conclusion: The Comfrey ointment accelerated the healing process of enoxaparin injection-induced bruising in patients with ACS. It is recommended as a safe and simple approach for these patients.

• Human Ecology Research
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• v.61 no.2
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• pp.263-280
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• 2023

This study examined four ecological systems, namely individual, family, school, and media environments. A series of moderator analyses were conducted to examine variations in effect size estimates across the study characteristics. The current study estimated that the effect size results were gleaned from 360 primary studies, including 90 journal articles and 270 thesis/dissertations, published between 2011 and 2022. The current meta-analysis results supported the ecological framework. That is, the impact of each ecological system on the development of positive and negative peer relationships varies depending on age groups and protective-risk factors. Specifically, for positive peer relationships, the largest effect size of the protective factor was found at the individual level for young and school- aged children, but at the school level for adolescents. Regarding the risk factors for positive peer relationships, the media was the ecological system with the strongest effect size for both young children and adolescents, while the individual-level demonstrating the strongest effect for school-aged children. Results from this meta-analysis allow us to identify some vital intervention areas in terms of healthy peer-relationship development, which should be of considerable interest to the educators and policymakers who are responsible for assessing and intervening with at-risk young children, school-aged children, and adolescents. From a practical standpoint, the current meta-analysis results are expected to contribute to developing effective prevention initiatives by targeting specific protective and risk factors for peer relationship development on the ecological system level.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1729-1732
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• 2006

We proposed a new Mercury-free Flat Fluorescent Lamp (MFFL) for LCD backlight which shows a wide, stable operating voltage margin, high luminance and efficiency. In this paper, we expanded the single cell with 4 inch diagonal size into the multi-cell for the large size LCD-TV backlight application, examined its operating characteristics and proposed a driving scheme for 2-bit areal selective dimming control.

• Proceedings of the Microbiological Society of Korea Conference
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• 2002.10a
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• pp.175-179
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• 2002

The assemblies of our partial genomic sequence data of Sphingomonas chungbukensis DJ77, with the total size of 877,928 bp, was done by TIGR Assembler. The total size of our current obtained contigs was about 0.73 Mb. A comparative genome analysis between our uncompleted genome and the other completed genomes was performed by taking advantage of the availability of multiple complete genomes in COGs database (Clusters of Orthologous Groups of proteins) to produce the genomic prediction of our S. chungbukensis DJ77. This analysis based on homologues search among completed genomes provides good initial step to our better assigning putative function to predicted coding sequences.

• Korean Chemical Engineering Research
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• v.53 no.4
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• pp.440-444
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• 2015

Effects of operating variables on the solid circulation rate were investigated in a three-phase circulating fluidized bed, of which inside diameter was 0.102m and height was 3.5m, respectively. Gas velocity, primary and secondary liquid velocities, particle size and height of solid particles piled up in the solid recycle device were chosen as operating variables. The solid circulation rate increased with increasing primary and secondary liquid velocities and height of solid particles piled up in the solid recycle device, but decreased with increasing particle size. The value of solid circulation rate decreased only slightly with increasing gas velocity in the riser. The values of solid circulation rate were well correlated in terms of dimensionless groups within the experimental conditions.

• Journal of the Korean Ceramic Society
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• v.42 no.3 s.274
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• pp.171-177
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• 2005

The effect of variation in particle size of WC and Co powder on the properties of WC-Co alloys was investigated. WC and Co powders having different particle sizes were used in the fabrication of $WC-10\;wt\%$Co composites. High hardness and low fracture toughness alloy was obtained with the decrease in WC particle size regardless of Co particle size. It was newly found in this investigation that the initial particle size of Co as well as WC had a great role in the microstructure and properties of WC-Co hard materials. The average grain size and fracture toughness of WC-Co alloys using same WC powder size increased and their hardness decreased with the use of relatively finer Co binder.

• Journal of Practical Engineering Education
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• v.14 no.3
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• pp.505-512
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• 2022

The purpose of this study is to synthesize effects of the living lab-based education through meta-analysis. Seven primary studies reporting the effect of living lab-based education were carefully selected for data analysis. Research questions are as follows. First, what is the overall effect size of the living lab-based education? The overall effect size refers to the effect on the cognitive and affective domains. Second, what is the effect size of the living lab-based education according to categorical variables? Categorical variables are outcome characteristics, study characteristics, and design characteristics. Results are summarized as follows. First, the overall effect size of living lab-based education was 0.347. Second, the effect size according to the cognitive domain was 1.244 for information process, 0.593 for communication, 0.261 for problem solving, and 0.26 for creativity. Third, the effect size according to subject area was shown in the order of electrical and electronic engineering 1.146, technology and home economics 0.489, artificial intelligence 0.379, and practical arts 0.168. Fourth, the effect size according to school level was 1.058 for high school, 0.312 for middle school, and 0.217 for elementary school. Fifth, the effect size by grade level was 0.295 when two or more grades were integrated and 0.294 for a single grade.