• The Journal of the Korea Contents Association
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• v.21 no.5
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• pp.398-408
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• 2021

The purpose of this study is to verify the mediating effects of difficult in emotional regulation and perceived social support on the relationship between adult ADHD tendency and smartphone addiction. For this study, Data were collected from 348 adults in 20s to 30s who live in Seoul, Gyeong-Gi Provinces. The SPSS 21.0 program was used to analyze the statistical data. The data was analyzed by structural equation modeling test mediating effects with AMOS and Mplus.. The results of the analysis were as follows: First adult ADHD tendency was positively correlated with difficulties in emotional regulation and smart phone addiction, while perceived social support was negatively correlated with those variables. Second difficulties in emotional regulation was partially mediated adult ADHD tendency and perceive social support. Third difficulties in emotional regulation and perceived social support had a dual mediating effect on adult ADHD tendency and smartphone addiction. These results reiterate the difficulties in emotional regulation is a determinant for the influence of adult ADHD on smartphone addiction, and suggest that smartphone addiction as an avoidant alternative activity could be reduced by overcoming the difficulties in emotional regulation and promoting the perceived social supports. Finally, some limitations of this study and suggestions for further researches were discussed.

• Journal of the Korean GEO-environmental Society
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• v.23 no.2
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• pp.13-23
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• 2022

The ground-structure interaction of the bridge foundation has been pointed out as a major factor influencing the behavior of the bridge during earthquakes. In this study, the effect of characteristics of ground and bridge foundation on the earthquake vulnerability is investigated. From the pseudo-static analysis, it is confirmed that non-linearity becomes lesser and horizontal load becomes greater when surcharge is considered. It is also found that as the ground worsens and the size of foundation decreases, horizontal load reduces. To derive reasonable structural model for bridge foundation, fragility curve is obtained considering four conditions (fixed condition, equivalent linear condition, non-linear without surchage condition, non-linear with surcharge condition) and compared. Seismic analysis is performed on single pier with Opensees. From the earthquake vulnerability analysis, it is found that shallow foundation can be assumed as fixed condition. In conservative approach, stiffness of spring can be obtained based on Korean highway bridge design code for pile foundation which can consider the ground condition.

• Journal of Digital Convergence
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• v.20 no.4
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• pp.23-30
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• 2022

This study analyzed the effects of e-sports games on psychological well-being and life satisfaction of individuals by focusing on social and psychological aspects, recognizing e-sports games as subjective area activities based on psychological experiences as well as a means of leisure activities. To this end, 250 game users with actual experience in online games were analyzed using a structural equation modeling(SEM). The research results are as follows. First, except for other's emotion appraisal, which was a sub-factor of emotional intelligence of e-sports game users, self-emotional appraisal, use of emotion and regulation of emotion were found to have a significant positive effect on psychological well-being. Second, psychological well-being in e-sports games was found to have a significant positive relationship with life satisfaction, and psychological well-being was found to significantly mediate the relationship between emotional intelligence and life satisfaction. The findings of this study imply that managerial implications for related organizations as a platform that could support individual psychological well-being in a situation where the stress level of young adults as well as teenagers in a non-face-to-face environment is increasing.

• Environmental and Resource Economics Review
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• v.30 no.4
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• pp.557-579
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• 2021

Collective energy is an intermediate stage in energy conversion and has a great influence on the power structure as a distributed power source. However, the problem of the collective energy business has recently emerged due to the worsening profitability of some collective energy operators. This study measured the technical efficiency of major operators through the estimation of the production efficiency of Korean collective energy operators, and based on this, we looked at ways to improve the profit structure of operators. After collecting detailed data from 16 collective energy operators between 2016 and 2019, the production efficiency of operators was estimated using the panel stochastic frontier model. As a result of the estimation, combined steam power operators showed the highest production efficiency and reverse CHP operators showed the lowest efficiency. Furthermore, as a result of examining the factors influencing profitability, it was confirmed that production efficiency has a positive effect on overall profitability. However, businesses with a high proportion of heat production, such as small district electricity operators, profitability was lower. This phenomenon is due to the structural limitations of the current heat sales market. Hence, the adjustment of the heat sales unit price is necessary to improve profitability of collective energy operators.

• Composites Research
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• v.35 no.3
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• pp.147-152
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• 2022

Low-temperature characteristics according to internal temperature conditions during rotational molding of Type 4 pressure vessel liners were studied in this paper. Since rotational molding has a sensitive effect on the formability of the liner depending on the temperature conditions, the temperature conditions for the polyamide used should be accurately set. The structural changes of polyamide as the liner material was analyzed the surface by atomic force microscope (AFM), and the crystallinity measured with a differential scanning calorimeter (DSC) is used to evaluate the change of the mechanical strength value at low temperature. In addition, the formability of the liner was confirmed by observation of the yellow index inside the liner. As a result, as the melting range of the internal temperature becomes wider, the yellow index shows a lower value, and the elongation and impact characteristics at low temperatures are improved. It was also confirmed that the structure of the polyamide was uniform and the crystallinity was high by AFM and DSC. These experimental results contribute to the improvement of characteristics at low temperatures due to changes in temperature conditions during rotational molding.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.3
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• pp.25-29
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• 2022

Recently, the importance of electronic packaging technology has been attracting attention, and heterogeneous integration technology in which chips are stacked out-of-plane direction is being applied to the electronic packaging field. The 2.5D integration circuit is a technology for stacking chips using an interposer including TSV, and is widely used already. Therefore, it is necessary to make the interposer mechanically reliable in the packaging process that undergoes various thermal processes and mechanical loadings. Considering the structural characteristics of the interposer on which several thin films are deposited, thermal stress due to the difference in thermal expansion coefficients of materials can have a great effect on reliability. In this study, the mechanical reliability of the metal pad for wire bonding on the silicon interposer against thermal stress was evaluated. After heating the interposer to the solder reflow temperature, the delamination of the metal pad that occurred during cooling was observed and the mechanism was investigated. In addition, it was confirmed that the high cooling rate and the defect caused by handling promote delamination of the metal pads.

• Journal of Korea Port Economic Association
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• v.37 no.4
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• pp.71-87
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• 2021

This study aims to reveal how a port affects the living conditions of its neighborhood area with a case study of Pusan New Port and to suggest several implications to port policy. PLS-SEM reflective measurement model satisfies the criteria on reliability and validity, and also structural model meets the criteria in terms of R2, path coefficients' significance and predictive relevance(Q2). The results of PLS-SEM support the hypotheses of this study: The expansion of Pusan New Port contributes to the improvement of living conditions of Gangseo-gu(nearby area) through its significant and sequential effects on the employment and population increase of Gangseo-gu. The originality of this study can be found in enunciating that a port plays a role as a driving force of the betterment of living conditions of its nearby Gu-level area. In terms of policy, central and local governments and port related companies should cooperate with each other to reinforce the acceptability of port policy through the improvement of the living conditions of port neighborhood area. To evaluate comprehensively the influence of a port on its neighborhood area, a further study needs to identify how a port affects the quality of life of the area or what kinds of socio-economic effects a port has on the area.

• Applied Chemistry for Engineering
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• v.33 no.3
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• pp.309-314
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• 2022

Carbon dots (CDs) are few nanometer-sized carbon-based nanoparticles and emerging candidate materials in various fields such as biosensors and bioimaging due to their excellent optical properties and high biocompatibility. However, most CDs, emitting blue light, have limited their application in biomedical fields due to the low penetration of short-wavelength lights into the biological system. Therefore, there has been enormous need to develop long-wavelength emitting CDs. In this study, red-emitting CDs were successfully synthesized through the hydrothermal reaction of p-phenylenediamine with hydrochloric acid. In addition, the effect of the amount of hydrochloric acid on the formation of carbon dots, resulting in the variation of the chemical structures of CDs, were investigated, which was confirmed with the intensive structural analyses using infrared and X-ray photoelectron spectroscopy. It was found that the chemical structure of CDs governed their optical properties and quantum yield. Therefore, this study provides an insight into the role of acid in forming red-emitting CDs as the optimal probe for biomedical application.

• Journal of the Korean Wood Science and Technology
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• v.31 no.4
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• pp.24-30
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• 2003

In order to develop structural 'bamboo zephyr board', properties of boards produced by various methods making zephyr were estimated. All of boards were tested with KS(Korean Standards) F 3014 Particle board, and results were summarized as follow. The zephyr boards produced by final 1.5 mm roller space had the best properties(MOR, MOE and IB strength) among boards produced by different final roller space. Also, they had the best properties(MOR and MOE) in bending test after 1 hour soaking treatment after 2 hour-boiling in water, which were similar to properties of boards in dry-condition. Thickness swelling(TS) of all boards was less than 12% required to the Korean Standards A 3014. Zephyr boards produced by final 1.5 mm roller space also had the lowest values among all of boards. Boards produced by non-treatment (in green condition) had the better strength than those of boards produced by different pre-treatment methods(boiling in water and in 0.3% NaOH) in bending test.

• The Journal of the Korea Contents Association
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• v.21 no.11
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• pp.333-349
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• 2021

As information is recognized as an important asset of an organization, organizations are increasing their resource input for knowledge management. In particular, the enterprise content management system(ECMS) is a solution for organization-oriented content management, and it has high utility by helping to achieve business performance through systematic utilization of content and improve the level of internal information security. The purpose of this study is to suggest a plan to improve the intention to use organizational employee's ECMS and to suggest the effect of the relationships between information system quality characteristics and work environment characteristics on intention to use. In this study, a research hypothesis was presented based on previous studies, a questionnaire was conducted on workers of organizations that adopted an ECMS, and the hypothesis was verified by applying structural equation modeling. As a result of the analysis, information and service quality of the ECMS and task interdependence increased the intention to use, but task conflict decreased the intention to use. In addition, task interdependence and task conflict moderated the positive relationship between the quality factors of the ECMS and the intention to use it. This study has implications in terms of suggesting the direction of the organization's behavior through factors that increase the use of ECMS.