• The Journal of the Convergence on Culture Technology
• /
• v.6 no.1
• /
• pp.269-278
• /
• 2020

The purpose of this study is to verify the effectiveness of problem-based learning on self-directed learning ability and learning flow of junior college students. The study was conducted on 248 students from five departments who participated in the faculty learning community program, which was supported by the Center for Teaching and Learning Development at D University in Busan. The effectiveness of the survey conducted before and after the application of the problem-based learning method was examined to show statistically significant changes in both self-directed learning ability and learning flow. A survey on satisfaction with the problem-based learning method showed that 66.2% of all students were satisfied with their classes overall, and 64% of the respondents said that the problem-based learning method helped them understand the course, which allowed them to verify the effectiveness of the study method. This research is meaningful in that it can be used as a basic data for the search for learner-centered education methods required by the era of the fourth industrial revolution.

• The Journal of the Convergence on Culture Technology
• /
• v.6 no.4
• /
• pp.761-766
• /
• 2020

Phenylamine derivatives are substances that have a biochemical action and are widely applied as psychotropic drugs. In particular, with regard to the quantitative analysis of substances such as ephedrine, amphetamine, pentermine, and dopamine, many previous studies such as electrochemical, vacuum ultraviolet method, and gas chromatography have been conducted. However, there have not been many studies on the structural characteristics of molecular units. Therefore, In this study, we used (HyperChem8.0's, HC) semi-empirical PM3 method to calculate the total energy, band gap, electrostatic potential, and net charge of ephedrine, amphetamine, pentamine and dopamine to investigate the chemical properties of each derivative according to the molecular structure change. The results showed that for total energy -43,171.8, -32,9538.3, -36,407.3 and -43,061.2 Kcal/mol, respectively, while for band gaps, 10.16379377, 9.9531666, 9.7878002 and 9.0589282 eV. Also, for electrostatic potentials, 1.301~-0.045, 1.694~0.299, 0.694~-0.158 and 1.587~-0.048 respectively. Finally, looking at the distribution of net charges, the oxygen atoms, nitrogen atoms and carbon atoms were -0.312~-0.242, -0.161~-0.051 and +0.13~-0.12 respectively. These results are expected to lead to chemical action centered on phenyl radicals and oxygen and nitrogen atoms common to phenethylamine derivatives.

• Fire Science and Engineering
• /
• v.34 no.3
• /
• pp.67-75
• /
• 2020

In this study, the risk of heat generation due to normal and overload currents that vary with the abnormal loosening angle of wire-connecting bolts were identified. The risks were analyzed based on the thermal characteristics to minimize the carbonization accidents of terminal blocks inside distribution panels typically used in industrial sites. We applied a method for measuring the heating temperature and temperature variations in the terminal blocks in real-time by installing a resistance temperature detector sensor board in the terminal block. The experimental results showed that the terminal block model with a low-rated current exhibited a higher heating temperature, thus, confirming the need to select the terminal block capacity based on load currents. Additionally, the higher the rated current of the terminal block with a high-rated current and the higher the degree of loosening, the faster the carbonization point. Such heating temperature monitoring enabled real-time thermal temperature measurement and a step-by-step risk level setting through thermal analysis. The results of the measurement and analysis of carbonization risks can provide a theoretical basis for further research regarding the risk of fire due to carbonization. Furthermore, the deterioration measurement method using the temperature sensor board developed in this study is widely applicable to prevent fires caused by poor electrical contact as well as risk-level management.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.36 no.4
• /
• pp.213-221
• /
• 2018

South Korea has been reluctant to open its geospatial information overseas to ensure security as a divided country. However, this cannot continue as the domestic and international environments related to geospatial information and the industrial ecosystem of information and communication technologies have been changing dramatically. Within this context, this study aims to analyze the causal relations among relevant variables and how they change and interact with time using a systems thinking process. First, causal maps were created for the domains of national security, map-based convergence service, and corporate competition. Then, the causal maps for each domain were integrated, based on which the points for policy intervention and dominant feedback loops were identified. The analysis results showed that securing the self-sufficiency of domestic geospatial businesses is a key element to determine the whole causal map, and the variable that changes the dominant feedback loop from a vicious circle to a virtuous one is the decision to open geospatial information overseas. In this study, I found the policy leverage that is a policy intervention point that can produce a great effect with little input by building a causal map of the interactions between major variables. This study is significant in that it identified and analyzed the dominant feedback loop as to which causal structure would dominate the system in the long term. The results of this study can be used to discuss not only the impacts of map data overseas opening on the national security and geospatial information industry, but also the interactions in the future when Google or other global companies request to release the geospatial information.

• Applied Chemistry for Engineering
• /
• v.25 no.1
• /
• pp.116-120
• /
• 2014

Light cycle oil (LCO), one of the by-products of the catalytic cracking gasoline manufacturing process, contains a lot of valuable aromatics. In particular, 2,6-dimethylnaphthalene (2,6-DMN) contained in LCO has been becoming important as the basic material of polyethylene naphthalate plastic and liquid crystal polymer, etc. If it were possible to separate and purify the valuable aromatic hydrocarbons (such as 2,6-DMN) from LCO, which have only been used as fuel mixed with heavy oil, it would be very meaningful in terms of the efficient use of resources. We investigated the high-purity purification of 2,6-DMN by the combined method of melt crystallization (MC) and solute crystallization (SC). The enriched DMN isomer mixtures (concentration of 2,6-DMN : 10.43%) recovered from LCO by distillation-extraction combination and the crystal recovered by MC used as raw materials of MC and SC, respectively. The solvent of SC used was a mixture of methanol and acetone (60 : 40 wt%). The crystal of 2,6-DMN with a high-purity of 99.5% was recovered by MC-SC combination. We confirmed that the MC-SC combination was one of the very useful combinations for the high-purity purification of 2,6-DMN contained in the enriched DMN isomer mixtures.

• Applied Chemistry for Engineering
• /
• v.27 no.2
• /
• pp.221-226
• /
• 2016

Production of eco-friendly and biologically harmless materials is strongly required in all industries. In particular, reducing volatile organic compounds in coating processes is extremely important to secure worker's safety. During recent two decades, extensive research works on water-borne polyurethane dispersion (PUD) have been continuously developed as an alternative to solvent-borne polyurethane. However, PUD was shown inferior mechanical properties to the organic solvent-borne polyurethane due to a limit to the molecular weight increase, which resulted in the limit of applications. To overcome this drawback, several approaches have been examined such as polymer blends and thermal/radiation induced crosslinking. Among these methods, the radiation curing system was suitable for industrialization because of the high crosslinking density and fast curing speed. In this study, we overcame the drawback for PUD via introducing benzophenone radiation curable units to PUD. We synthesized PUD films which possessed good dispersion in water for 30 days, increased Tg and Td more than $5^{\circ}C$ after UV curing film as well as improved young's modulus more than double.

• The Journal of the Convergence on Culture Technology
• /
• v.5 no.4
• /
• pp.373-378
• /
• 2019

In the marine area, the salt concentration in the soil increases, and the inland heavy metal pollution increases the damage of plants. In the inland industrial development area, researches on the genetic resources of plants together with the heavy metal accumulation of Co, Ni, Zn, and so on are required. Both of these problems have caused scientists to work hard to find plants that are likely to cause stress in plant roots. In this study, seeds of Arabis stelleri var. japonica collected near the shore were used for germination. The growth and development and tolerance of both Arabis and Arabidopsis seeds were investigated under laboratory culture conditions. As a result, Arabis showed resistance about 3 times in 250 mM nickle and cobalt, and more than 4 times in 1 mM zinc when compared to Arabidopsis. The tolerance of Arabis to Na salts increased by 20% or more at 50 mM concentration and Arabis was resistant to heavy metals and salt concentration. The accumulation of Na ions in the body was measured as a preparation for studying the intracellular mechanism. As a result, it showed a further decrease in resistance to ground water roots. It is considered that the activity of the exporting gene is important rather than the mechanism of accumulation.

• Journal of Digital Convergence
• /
• v.17 no.11
• /
• pp.1-7
• /
• 2019

This study analyzed the effects of labor aging on labor productivity using panel statistics of 16 local governments from 1995 to 2017. The aging of the labor force, defined as the proportion of workers aged 60 or older in total employment, in the results of the panel regression analysis considering regional fixed effects and various adjustment variables, has a very consistent and significant negative effect on labor productivity. For every 1% increase in aging, labor productivity decreases by about 0.14 ~ 0.20%. In addition, the per capita capital stock and human capital considered as adjustment variables contributed to the increase of labor productivity, and the unemployment rate, which is a proxy variable of the economic fluctuation, has a significant negative effect on labor productivity as expected. The coefficient of the industrial structure, which represents the share of the service industry in the whole industry, was positive, but is not significant. The results of this study suggest that the design and construction of economic and educational policies that can maintain and expand human capital are necessary to curb the reduction in labor productivity expected by the aging workforce.

• Journal of Digital Convergence
• /
• v.17 no.11
• /
• pp.327-337
• /
• 2019

The purpose of the current study was to examine dual mediation effect of executive function deficiencies and adaptive cognitive emotion regulation strategies in the relation of smartphone addiction and subjective well-being and to suggest implications for adult smartphone addiction intervention programs. A self-report survey was conducted to 148 adults(71 males and 77 females) and the mediation effect was evaluated by regression analyses. Key findings are as follows. First, executive function deficiencies showed mediation effect on the relationship between smartphone addiction and adaptive cognitive emotion regulation strategies. Second, significant mediation effect of adaptive cognitive emotion regulation strategies was not found on the relationship between smartphone addiction and subjective well-being. Finally, the relation of smarphone addiction and subjective well-being was mediated by executive function deficiencies and adaptive cognitive emotion regulation strategies. These results imply that it would be helpful to train executive function and foster emotion regulation strategies to the adult smartphone addiction groups. Finally, limitations of this study and suggestions for future research of the entire adult age group were discussed.

• Journal of Digital Convergence
• /
• v.17 no.11
• /
• pp.557-567
• /
• 2019

This investigation was conducted to derive future recognition and future competency of career counselors using future workshops and to verify the effectiveness of improving future adaptability. For this purpose, the future workshop was conducted for 25 career counselors and the data written and the discussion contents of the future workshop were analyzed. For analysis, word frequency analysis and corresponding sample T-verification were conducted, and the main words were derived through consensus. The results, First, the keywords of future recognition showed high frequency of robot, artificial intelligence, leisure, education, convenience, and the disabled. Second, the future labor sites projected the most changes due to high technology. Third, at the career counseling site, professional career counselors and robot counselors related to the fourth industrial revolution are expected to appear. Fourth, future competencies of career counselors were derived from information processing ability, professional counseling ability, communication ability, and ethical consciousness. Finally, it was confirmed that the future adaptability of career counselors increases after participating in future workshops, and the future competencies derived from this study are expected to be used for job training of career counselors.