• Journal of The Korean Association of Information Education
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• v.20 no.6
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• pp.597-606
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• 2016

By utilizing the TPCK model, this research analyzed the present state of pre-service elementary teachers' competencies related to the use of technology. It also conducted the Importance-Performance Analysis to prioritize remedial issues to improve curriculum related to the use of technology. A survey was conducted to 165 pre-service teachers who are senior students at a University. A questionnaire was used to investigate pre-service teachers' perception on the importance and performance related to Technology Knowledge, Technological Pedagogical Knowledge, Technological Content Knowledge and Technological Pedagogical Content Knowledge. As the result of the t-test, significant differences between importance scores and performance scores were found in all the competencies and 17 sub-competencies. In addition, as the results of the importance-performance analysis, 5 sub-competencies were found to be concentrated for the improvement, and 4 sub-competencies were found to be kept up because of their good work. Also 5 sub-competencies were turned out to have low priority, and 3 sub-competencies were turned out to be possible overkill.

• The Journal of the Korea Contents Association
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• v.16 no.8
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• pp.729-742
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• 2016

The purpose of this study is to investigate the influence of parenting and peers on youth engagement to pornography media, the fourth year data of the fourth-grade panel (first year at middle school) and the fourth-year data of the eighth-grade panel (first year at high school) were analyzed. The number of cases investigated for this panel study were 2,378 subjects among the fourth-year panel of the fourth grade and 2,361 subjects among the fourth-year panel of middle schoolers. But this study, the total of 720 subjects that the response were made in the pornography items are analyzed. The result of this study reveals that male students were more likely to be addicted to pornography than female students. Also, inconsistency and excessive intervention among the parenting attitudes and peer attachment and numbers of delinquent friens among the peer factors were shown to have influence on youth addiction to pornography. Based on such results, a proposal that a plan to increase the parental education and strengthen peer relationships is important ahead of the Controlled intervention in the meantime was made.

• Journal of the Korea Convergence Society
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• v.7 no.6
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• pp.287-295
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• 2016

This study was conducted of students in their youth, who were having behavioral and emotional problems, anxiety, depression, and ADHD in their school. The participants took part in equestrian sports programs(equestrian program and apparatus program) twice a week, for 60 minutes each. To make progress in the study, mainly 4 scales are used as the standards of preliminary and post inspections : emotional and behavioral development scale, anxiety scale, depression scale, and ADHD scale. After conducting two-way ANOVA analysis, the conclusion was made as follows. The equestrian sports and horse riding exercise program which were used in this study did had an positive effect on emotional and behavioral scale, depression scale, anxiety scale, and ADHD scale. Moreover, it is determined that the equestrian sports had more positive effects than the equestrian sports which used apparatus. However, to precisely compare and contrast the effects of equestrian sports programs and apparatus programs, the follow-up studies need to limit the control group.

• Korean Chemical Engineering Research
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• v.56 no.4
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• pp.469-473
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• 2018

When pure hydrogen was supplied to the stationary PEMFC generally using the reforming gas, its characteristics were compared with the vehicle PEMFC. The effect of varying the amount of hydrogen supply to the anode on the overall performance was compared. The variation of hydrogen supply in the range of 1.0~1.7 excess (stoi.) had little effect on the OCV of stationary and vehicle MEA (Membrane and Electrode Assembly). At 0.7 V, the current density of the stationary MEA was about 16% higher than that of the vehicle MEA. I-V performance, impedance, and LSV were measured with varying relative humidity. Both OCV and electrolyte membrane resistances decreased with increasing relative humidity. The hydrogen permeability of the stationary MEA was lower than that of the vehicle MEA, showing that the durability of the stationary membrane could be higher than that of the vehicle membrane.

• Spatial Information Research
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• v.2 no.1
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• pp.3-14
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• 1994

The external diseconomy has been accelerated by the megaspatial structure of metropolis such as Seoul Capital Region(below SCR), Korea in which the more than 10 million populations inhabit. The main course for It could be elaborated by the overconcentration of the urban and regional function of various kinds. The study is performed to analyze quantitatively the status quo of the region as described above and proceed into forecasting the future population trend, the land use at location for the increment of regional population and to set the location of new towns in Seoul Capital Region System projected by the methods in computer algorithm of descriptive models such as the simple and multiple regress ion analysis models, the gravity model and the facility location on a plane model analysis. The goal and object ive of the metropolitan planning are to decentralize the regional growth management to the optimum degree, which will not hinder the economic growth of the region, but the result of the study is that we can not discourage the functional concentration of Seoul Capital Region and, we have to provide the region with the appropriate new towns.

• Journal of the Microelectronics and Packaging Society
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• v.11 no.3 s.32
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• pp.91-97
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• 2004

PBT thin films were formed by rf-magnetron sputtering on $Pt/Ti/SiO_2/Si$ substrate. Bulk-PZT target containing $5\%$-excess PbO was used. After PZT thin films had been deposited at room temperature, remaining portion of the thin film was formed by in-situ process. The ferroelectric perovskite phase was formed at $650^{\circ}C$. The leakage current property was improved dramatically by 2-step sputtering, and in the sample containing optimum thickness of room temp.-layer very low leakage current of $2{\times}10^{-7}A/cm^2$ was shown. As a result of the investigation on the leakage current mechanism, the electrical conduction mechanism in all PZT thin films formed by several conditions was confirmed as bulk-limited mechanism.

• Journal of the Korean GEO-environmental Society
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• v.4 no.4
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• pp.17-23
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• 2003

Accurate prediction of consolidation behaviors of the soft ground improved by plastic board drains is not easy because the consolidation characteristics of the improved ground has not been fully elucidated yet. The shape of drains is one of the most important factors which affect the consolidation characteristics of the improved ground. In this paper, a series of model consolidation tests of soft clay ground improved by plastic board drain were carried out, in order to investigate the effect of both plastic board width and stress level on consolidation characteristics of the improved ground. As the results, behaviors of both settlement and excess pore pressure dissipation were elucidated. Also, the non-uniform distribution of water content in the model ground was obtained. Then, in order to investigate the effect of vertical drainage on the consolidation behavior in the model tests, the comparison between experimental consolidation behaviors and Barron's theoretical ones were carried out. As the results, it was elucidated that the consolidation behavior in the model tests was affected not only by radial drainage but also by vertical drainage.

• Journal of the Korean GEO-environmental Society
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• v.17 no.2
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• pp.31-39
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• 2016

Vertical drain has usually been used to accelerate the consolidation of soft clay deposits with high moisture content. Busan thick clay deposits are subjected to artesian pressure from an aquifer in sand and gravel layers. However, effect of artesian pressure existing in drainage-installed soft ground on consolidation behaviors is not well known. This paper investigates the consolidation behavior of drainage-installed soft ground at the Nakdong river estuary with artesian pressure and without artesian pressure. A series of one-dimensional large size column test was carried out to find out the consolidation characteristics of clay. Test results indicated that total settlement of clay with artesian pressure was higher than that without artesian pressure because effective stress decreased due to upward flow. Dissipation rate of excess pore water pressure delayed and excess pore water pressure did not fully dissipate in clay layer with artesian pressure. Undrained shear strength of clay ground with artesian pressure was lower than that without artesian pressure.

• KSBB Journal
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• v.14 no.5
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• pp.628-632
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• 1999

Optimization of the medium and fermentation conditions for erythritol production has been studied. We have found that the optimal carbon source was glucose at the concentration of 400 g/L. The optimal temperature was 3$0^{\circ}C$ with excessive aeration. Improved erythritol productivity was achieved by reducing the yeast extract from 5 g/L to 3g/L while adding 2.7 g/L urea, 1.79g/L $K_2HPO_4, and 0.18g/L MgSO$_4$. 7$H_2O. The erythritol productivity increased from 0.747 g/L/h to 1.071 g/L/h and the yield increased from 31.4% to 45.2%. The byproduct glycerol was reduced from 96.6g/L to 45.7g/L as well. We have performed 5L fermentation with and without the pH control. The erythritol productivity with the pH control was about 30% lower than that without pH control. Excessive foaming of 5L fermentation has been observed during fermentation.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.1
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• pp.21-27
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• 2015

In order to meet the current emission regulations (EURO-6), it is necessary to significantly reduce $CH_4$ and $NO_X$ emissions. This study investigated the effect of a reduction in the valve overlap on the combustion and emission characteristics of a hydrogen-compressed natural gas engine under a part-load operating condition. The combustion and emission characteristics were analyzed for each fuel using the original camshaft and an altered camshaft with reduced valve overlap. The results showed that the thermal efficiency was decreased and the fuel flow was increased when using the altered camshaft. The $CO_2$ and $CH_4$ emissions were increased as a result of the reduced thermal efficiency. Under lean operating conditions, the $NO_X$ emission was decreased compared with one of the conventional camshaft. Thus, under the same fuels and operating conditions, it had a harmful influence on the emission characteristics and thermal efficiency.