• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.5
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• pp.296-300
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• 2021

The performance of devices has been improved with fine processes from planar to three-dimensional transistors (e.g., FinFET, NWFET, and MBCFET). There are some problems such as a short channel effect or a self-heating effect occur due to the reduction of the gate-channel length by miniaturization. To solve these problems, we compare and analyze the electrical and thermal characteristics of FinFET and GAAFET devices that are currently used and expected to be further developed in the future. In addition, the optimal structure according to the Fin shape was investigated. GAAFET is a suitable device for use in a smaller scale process than the currently used, because it shows superior electrical and thermal resistance characteristics compared to FinFET. Since there are pros and cons in process difficulty and device characteristics depending on the channel formation structure of GAAFET, we expect a mass-production of fine processes over 5 nm through structural optimization is feasible.

• Journal of the Korean Institute of Gas
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• v.26 no.2
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• pp.1-8
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• 2022

The purpose of this study is to prepare GPTMS((3-Glycidoxypropyl) trimethoxysilane)-SiO₂ nanofluid and analyze the effect of nanofluid injection on carbonate reservoirs. Structural analysis of silica nanoparticles modified by GPTMS was investigated by FTIR(Fourier transform infrared spectroscopy). C-H stretching vibrations at 2,950 cm^-1 indicating the silica surface modification with GPTMS were observed when the silane feed was over 0.5 mmol/g. Also, the coreflooding test by nanofluid injection on the aged limestone and dolomite plug samples was carried out with different particle concentration and flow rate. The incremental oil recovery was up to 18.9%, and contact angle and permeability of carbonate samples were changed by the effect of nanoparticle adsorption on pore which caused wettability alteration and pore size change. Therefore, the prepared nanofluid will be utilized as an injection fluid for enhancing oil recovery and modifying fluid flow properties such as change of rock wettability and permeability in carbonate reservoirs.

• The Journal of Advanced Prosthodontics
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• v.16 no.2
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• pp.105-114
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• 2024

PURPOSE. This study aimed to evaluate the effect of pretreatment of three different universal adhesives (Single Bond Universal [SBU], All-Bond Universal [ABU], and Prime&Bond universal [PBU]) on the bonding durability of an adhesive (Panavia F 2.0, PF) and a conventional (Duo-Link, DL) resin cements to air-abraded zirconia. MATERIALS AND METHODS. Rectangular-shaped zirconia specimens were prepared. The chemical composition and surface energy parameters of the materials were studied by Fourier transform infrared spectroscopy and contact angle measurement, respectively. To evaluate resin bonding to the zirconia, all the bonding specimens were immersed in water for 24 h and the specimens to be aged were additionally thermocycled 10000 times before the shear bond strength (SBS) test. RESULTS. The materials showed different surface energy parameters, including the degree of hydrophilicity/hydrophobicity. While the DL/CON (no pretreatment) showed the lowest SBS and a significant decrease in the value after thermocycling (P < .001), the PF/CON obtained a higher SBS value than the DL/CON (P < .001) and no decrease even after thermocycling (P = .839). When the universal adhesives were used with DL, their SBS values were higher than the CON (P < .05), but the trend was adhesive-specific. In conjunction with PF, the PF/SBU produced the highest SBS followed by the PF/ABU (P = .002), showing no significant decrease after thermocycling (P > .05). The initial SBS of the PF/PBU was similar to the PF/CON (P = .999), but the value decreased after thermocycling (P < .001). CONCLUSION. The universal adhesive pretreatment did not necessarily show a synergistic effect on the bonding performance of an adhesive resin cement, whereas the pretreatment was beneficial to bond strength and durability of a conventional resin cement.

• Nuclear Engineering and Technology
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• v.56 no.3
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• pp.1066-1080
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• 2024

SMART100 has a containment pressure and radioactivity suppression system (CPRSS) for passive containment cooling system (PCCS). This prevents overheating and over-pressurization of a containment through direct contact condensation in an in-containment refueling water storage tank (IRWST) and wall condensation in a CPRSS heat exchanger (CHX) in an emergency cool-down tank (ECT). The Korea Atomic Energy Research Institute (KAERI) constructed scaled-down test facilities, SISTA1 and SISTA2, for the thermal-hydraulic validation of the SMART100 CPRSS. Three separate effect tests were performed using SISTA1 to confirm the heat removal characteristics of SMART100 CPRSS. When the low mass flux steam with or without non-condensable gas is released into an IRWST, the conditions for mitigation of the chugging phenomenon were identified, and the physical variables were quantified by the 3D reconstruction method. The local behavior of the non-condensable gas was measured after condensation inside heat exchanger using a traverse system. Stratification of non-condensable gas occurred in large tank of the natural circulation loop. SISTA2 was used to simulate a small break loss-of-coolant accident (SBLCOA) transient. Since the test apparatus was a metal tank, compensations of initial heat transfer to the material and effect of heat loss during long-term operation were important for simulating cooling performance of SMART100 CPRSS. The pressure of SMART100 CPRSS was maintained below the design limit for 3 days even under sufficiently conservative conditions of an SBLOCA transient.

• The Journal of the Petrological Society of Korea
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• v.16 no.1 s.47
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• pp.27-37
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• 2007

Here we discuss a geochemical characterisitc of rare earth element (REE) pattern of a Precambrain leucogranitic gneiss at Imweon, Gangwon Province, Korea. The outcrop includes biotite gneiss xenolith. The leucocratic granite gneiss contacting with biotite gneiss is pegmatitic. However, there is no evidence of contact metamorphism between biotite gneiss and leucocratic-pegmatitic granite gneiss. The leucocratic granite gneiss shows a specific phenomenon of M-type (convex curved) tetrad effect in chondrite-normalized REE patterns with large negative Eu anomaly. The degree of REE tetrad effect in the leucocratic-pegmatitic granitec gneiss is weak and shows partly W-type (concave curved) tetrad effect. The Eu anomaly of leucocratic granite gneiss has close relationship with the degree of tetrad effect as well as Ca/Sr ratio. Our results suggest that the REE tetrad effect from the leucocratic granite gneiss should be formed during differentiation process of granitic magma. We also confirmed that the weathering might affect Eu or Ce anomaly rather than the formation of REE tetrad effect in granitic rock.

• Journal of Korea Society of Industrial Information Systems
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• v.26 no.6
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• pp.97-118
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• 2021

This study empirically examines the effect of the psychological empowerment of airline cabin crews on customer-focused job performance attitude, service behavior by CSM, and service behavior beyond CSM. The research model and associated hypotheses were verified with the structural equation model. The findings of the study reveal that psychological empowerment has a effect on customer-focused job performance attitude and service behavior by CSM, but no effect on service behavior beyond CSM. And it is also shown that customer-focused job performance attitude has an effect on service behavior by CSM but no effect on service behavior beyond CSM. In addition, customer-focused job performance attitude shows a mediating effect between psychological empowerment and service behavior by CSM. On the other hand, it is analyzed that there is no mediating effect between psychological empowerment and service behavior beyond CSM. This study implies that the psychological empowerment and customer-focused job performance attitude of cabin crews are important at point of contact with customers to improve service quality, and psychological empowerment reinforces service behavior by CSM on the premise of customer-focused job performance attitude.

• Journal of Service Research and Studies
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• v.12 no.4
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• pp.30-49
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• 2022

Recently, as the transition to the untact era due to COVID-19 accelerates, non-face-to-face and non-contact practices have become commonplace, and the OTT (Over-The-Top) service market that provides media content such as movies and broadcast programs through the open Internet is largely expanded and it is receiving great attention from the MZ generation, who are familiar with digital devices and environments. In this study, the effects of OTT service characteristics on MZ generation users' flow, satisfaction and brand loyalty were examined, focusing on Netflix users, one of the representative OTT service brands. In order to carry out this study, a total of 216 people who have used the Netflix OTT service platform were empirically verified by using the survey data of those who have used it for analysis. As a result of the analysis, it was found that among the characteristics of OTT service, contents diversity, convenience, and reliability had a positive (+) effect on flow. Also, flow has a positive (+) effect on satisfaction, and satisfaction has a positive (+) effect on brand loyalty. However, among the characteristics of the OTT service, the recommended service did not have a positive (+) effect on the flow, and the flow did not have a direct positive (+) effect on the brand loyalty. Flow had a positive (+) effect on the brand loyalty through satisfaction. Through this study, it is expected that the market revitalization of the OTT service-related industry and the increasing number of OTT service brands will be able to contribute to the establishment of marketing strategies for the MZ generation consumers, and to provide practical implications.

• Journal of the Korean Society of Child Welfare
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• no.58
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• pp.205-229
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• 2017

The purpose of this study was to examine gender differences in the impact of exposure to peer delinquency among elementary school-age students and the mediating effects of aggression. The study utilized 458 cases (220 male students, 238 female students) of data from the 2015 Korea Welfare Panel Study (KoWePS) conducted by the Korea Institute for Health and Social Affairs (KIHASA). The theoretical frameworks used in this study included Bandura's social learning theory, Akers' social learning theory, and Sutherland's differential association theory. The findings were as follows. First, there was no statistically significant effect on peer group's delinquency experience overall, aggression, and delinquency experience by gender. Second, male students' delinquency experience of their peer group had a statistically significant effect on their delinquency, however, this was not true for female students. Third, in the case of male students, aggression was found to mediate the relationship between peer group delinquency experience and their own delinquency, but not for female students. From these findings, we suggest a practical and policy-driven intervention plan, focusing on reducing the contact frequency of delinquency experience and aggression, The purpose of this study was to examine gender differences in the impact of exposure to peer delinquency among elementary school-age students and the mediating effects of aggression. The study utilized 458 cases (220 male students, 238 female students) of data from the 2015 Korea Welfare Panel Study (KoWePS) conducted by the Korea Institute for Health and Social Affairs (KIHASA). The theoretical frameworks used in this study included Bandura's social learning theory, Akers' social learning theory, and Sutherland's differential association theory. The findings were as follows. First, there was no statistically significant effect on peer group's delinquency experience overall, aggression, and delinquency experience by gender. Second, male students'delinquency experience of their peer group had a statistically significant effect on their delinquency, however, this was not true for female students. Third, in the case of male students, aggression was found to mediate the relationship between peer group delinquency experience and their own delinquency, but not for female students. From these findings, we suggest a practical and policy-driven intervention plan, focusing on reducing the contact frequency of delinquency experience and aggression, which was found to adversely affect elementary school students' delinquency.

• Journal of the Korean Applied Science and Technology
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• v.34 no.3
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• pp.525-535
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• 2017

In order to produce hydrophilic coating solution, which has superior antifogging and antifouling effect on the glass surface of solar cell module as well as improving photovoltaic efficiency, nanosilica was dispersed in an aqueous solution of Tween 20 and fluorosurfactant composed of decafluorobutane and polyethylene glycol. The antifogging effect at high temperature was excellent for all the coating solutions containing nanosilica, but the antifouling effect was observed when the content of nanosilica was over 6 wt%. As the content of fluorosurfactant increased, the initial water contact angle slightly increased and the antifogging effect remained well until 500 wiping with wet $Wipeol^{(R)}$. The antifouling effect was also excellent regardless of the content of fluorosurfactant, thus 0.1 wt% of the fluorosurfactant was enough for a coating solution production. From the AFM results, when 0.1 wt% to 0.3 wt% of the fluoro surfactant was added, the fractal structure of the coated glass surface was clearly existed and contributed to the better antifouling effect. The transmittance of coated glass surface was highest in TL-1 coating solution containing 0.1 wt% of fluorosurfactant, and the addition of fluorosurfactant in a larger amount than 0.1 wt% did not improve the transmittance. This result is in good agreement with the previous AFM result which shows a high surface roughness as well as a fractal structure formation for the TL-1 coating solution.

• Journal of the Korea Convergence Society
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• v.12 no.5
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• pp.197-205
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• 2021

TV home shopping companies are not limited to TV channels and phone-ordering channels, but are making efforts to expand their channels through mobile phones. Beyond its interaction and ubiquity using the web, it is expanding its contact point with consumers through mobile live broadcasting. Interacting, ordering, doing their own broadcasts within mobile App, and interacting and enjoying them are likely to differ depending on consumers' personality, such as playfulness and impulsivity. In this study, the effects of Two-way communication, Synchronicity and Ubiquity, which are the characteristics of mobile home shopping, on consumers' flow, and the effect on consumers' flow on mobile home shopping will vary depending on individual preferences. Interacting, ordering, doing their own broadcasts within mobile devices, and interacting and enjoying them are likely to differ depending on consumers' personal preferences, such as play and impulsive tendencies. As a result of the study, Two-way communication was found to have not significant on flow, and Synchronicity was also found to have no significant effect on flow. It was found that ubiquity had a significant effect on flow. Among the individuality, people with high playfulness have a positive effect on flow, and people with high impulsivity also have a significant effect on flow. Flow has been shown to have a positive effect on the intention to using mobile home shopping.