• Resources Recycling
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• v.28 no.6
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• pp.64-72
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• 2019

Fly ash has different chemical composition depending on the type and quality of flaming coal. Fly ash is classified according to carbon content and particle size. Waste glass powder is manufactured by crushing glass. Exterior Insulation Finish System (EIFS) is generally applied by using poly-styrene foam which is economical and has excellent thermal insulation performance. However, poly-styrene foam has excellent insulation performance, but it is vulnerable to fire, which is becoming a serious problem. In this study, using a fly ash and waste glass powder to produce a finishing mortar at high temperatures. Also, High temperature strength and flame retardant properties were tested according to the cover thickness. From the test result, finishing mortar prepared using fly ash and waste glass powder is due to the improved heat resistance by alkali-activated bonding. However, since the strength decreases at high temperatures, it is necessary to select an appropriate mixing proportion.

• Journal of Digital Convergence
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• v.15 no.11
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• pp.67-76
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• 2017

To conduct research using small group learning with advanced technology in school, small group collaborative learning was conducted in virtual reality called Second Life for high school history class to verify the effects of the role of group members (leader, group member) in collaborative learning activities in this study. Two classes of the second grade of high school were selected randomly and 20 groups were also randomly assigned, and each group was consisted of three members (1 leader and two group members). Academic achievement and satisfaction with academic activities were used to verify the effect of the role as measurement tools, and collected quantitative data were tested by independent sample t. As a result, it was found that performing the role of leader in collaborative learning activities in virtual reality was effective in promoting enhancing students' academic achievement and increasing satisfaction level. Lastly, utilization and improvement of small group collaborative learning using virtual reality in the field of education were discussed.

• Journal of Digital Convergence
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• v.15 no.11
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• pp.611-620
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• 2017

The purpose of this study was to investigate the relationship between emotional labor, job burnout and job satisfaction in instructors. The data were collected from 323 fitness center instructors using multistage stratified cluster random sampling method. With the collected data, factor analysis, reliability analysis, frequency analysis, correlation analysis, model fit tested, and structural equation model were performed by SPSS 23.0 and AMOS 20.0. The result of the analysis were summarized as follows. First, the emotional labor(inner behavior) impacts negative influence on job burnout of fitness center instructors. Second, the emotional labor(surface behavior) impacts positive influence on job satisfaction of fitness center instructors. Third, the job burnout impacts negative influence on job satisfaction of fitness center instructors. Fourth, the emotional labor(inner behavior) impacts positive influence on job satisfaction of fitness center instructors. Fifth, the emotional labor(surface behavior) does not influence on job satisfaction of fitness center instructors.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.6
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• pp.366-371
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• 2017

In this paper, we introduce an electrocardiogram (ECG) system designed to solve problems caused by wetgels and motion artifacts in measuring active movement. The system is called a dry-contact ECG and was designed by considering impedance matching between skin and electrode as well as the frictional electricity between electrode and clothes. In order to create the system, we measured impedance on the skin-electrode interface, and the result was applied to the electronic circuit scheme. Moreover, we added an electrode on the back of the measurement electrode to make a flow path to ground the electrical noise. The final ECG circuit and novel electrode were used to detect real human cardiac signals from a subject who was tested while standing still and walking. The signals obtained from the two activities were nicely shaped, without any motion artifact noise. We took electrode size into account in this study because the impedance depended on the area of the electrode. An electrode of 50 mm diameter showed the best curve for the ECG signal without any electrical noise.

• Journal of Korean Physical Therapy Science
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• v.24 no.3
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• pp.56-63
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• 2017

Purpose: This study aimed to investigate the effects of sitting posture on cervical flexion angle and pain during smart phone use. Method: This research was performed on 10 adult female students who use smart phones regularly, Each of the two groups of participants used the provided smart phone for 20 minutes while maintaining the given default posture. The evaluation order was randomly selected and the two groups were photographed twice before and after the experiment and were asked to answer if they felt pain during or after the experiment. Result: First, both upright sitting position and vertebra bent position pre and post experiment readings showed significant statistical difference (p<.05). And it is shown to be a factor that induces pain around the neck via increase in neck flexion angle. Second, although there were no significant statistical difference between the pre and post experiment readings of the upright sitting position results and the vertebra bent position results, the vertebra bent position readings showed bigger changes to the neck flexion angle then the upright sitting position readings. Third, all participants from both groups claimed pain in all the tested postures of smart phone usage. Conclusion: Smart phone usage for an extended amount of time in all body postures may prove to have a negative effect making the "optimal" smart phone usage position as a controlled time with neck stretches included in between short sessions.

• Food Science of Animal Resources
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• v.38 no.1
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• pp.180-188
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• 2018

The market size of home meal replacement (HMR) products has been gradually growing worldwide, even in Korea. In Korean HMR products, meat is the most important food ingredient compared with rice and vegetables. Therefore, this study aimed to evaluate changes in physiochemical and sensory aspects of beef under different preparation processes. For preparing four treatments, beef eye of round (ER) added with salt and sugar (treatment 1) and that without salt and sugar (treatment 2) were mixed with rice and frozen at $-50^{\circ}C$. Beef ER without salt and sugar was also topped onto the rice and frozen (treatment 3), and that was topped onto the rice and precooled before freezing (treatment 4). Physiochemical analyses included cooking and drip losses, shear force, color, salt soluble protein, and sensory attributes were tested. The results showed significantly higher drip loss and total loss in beef ER samples 1 and 2, which were mixed with rice, compared to beef ER samples 3 and 4, which were not mixed with rice. A significantly higher discoloration was also observed in beef ER samples 1 and 2, compared to that in samples 3 and 4. In the partial least squares regression (PLSR) analysis, beef ER sample 4 (precooled before freezing) was highly related to sensory attributes, such as flavor, overall acceptability, and juiciness, and far from non-preferred shear force. As a result, beef ER in HMR sample 4 was the most preferable to the sensory panel, and it had the most desirable physicochemical analysis outcomes.

• Journal of the Korean Regional Science Association
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• v.31 no.1
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• pp.3-20
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• 2015

The objective of this study is to identify the applicability of urban network theory. The degree of network and city size of 163 Si-Guns in Korea are used to perform an empirical analysis for 2005 and 2010. The result indicates that the effect of city size (based on central place theory) is still larger than the network effect (based on urban network theory). However, the effects are different according to the industrial types. The size-based effectis more efficient in manufacturing sector, whereas the network-based effect is more efficient in service industry. The trend from 2005 to 2010 indicates that there is an increasing pattern in network-based effect and decreasing patternin size-based effect. It is necessary to recognize continual benefit of the sized-based effect, however it is also important to distinguish different characteristics of the functional form by the size and network. The feasibility of the urban network theory is tested in this study with the empirical analysis and recommends the importance of policy implication with recognition of the distinction between size and network-based effects.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.11 no.1
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• pp.37-44
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• 2017

This study was to identify the factors influencing the quality of life for the elderly with disabilities in the aging society. For this purpose, this study tried to examine the relationship between the factors which are Social support, Decrease in depression of the elderly with disabilities and Quality of life for the elderly with disabilities, and also identify the moderating effect of living independence. This study tested the research model based on panel data of the elderly with disabilities in Korea Welfare Panel Study. Th result are as follows: First, social support(family support and peer support) positively impact on depression of the elderly with disabilities. Second, decrease in depression of the elderly with disabilities positively impact on the quality of life for the elderly with disabilities. Finally, the higher living independence of the elderly with disabilities, decrease in depression of the elderly with disabilities positively impact on life support services and treatment services whereas does not impact on leisure life significantly.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.3
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• pp.118-128
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• 2016

As the rural areas have experienced the population reduction and the aging, the service level of public transit decreases. This study analyzes the effecting factor to user satisfaction of demand response transport(DRT) as alternative to rural public transit by the quantile regression that aims at estimating either the conditional median or other quantiles of the response variable. Jeonbuk Province tested DRT operations in Dongsang of Wanju County and Sannae of Jeongup City each in 2015. The user DRT satisfaction of Wanju was higher than one of Jeongup in basic statistics analysis. The difference in satisfaction between higher quantile and lower quntile of Wanju is smaller than one of Jeongupy as a result of quantile regression analysis. Also, Wanju DRT continues the second test operation of DRT as satisfaction from Ordinary Least Squares(OLS) close to higher satisfaction quantile.

• Atmosphere
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• v.25 no.1
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• pp.155-167
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• 2015

A dynamical seasonal prediction system for boreal winter utilizing cryospheric information was developed. Using the Community Atmospheric Model, version3, (CAM3) as a modeling system, newly developed snow depth initialization method and sea ice concentration treatment were implemented to the seasonal prediction system. Daily snow depth analysis field was scaled in order to prevent climate drift problem before initializing model's snow fields and distributed to the model snow-depth layers. To maximize predictability gain from land surface, we applied one-month-long training procedure to the prediction system, which adjusts soil moisture and soil temperature to the imposed snow depth. The sea ice concentration over the Arctic region for prediction period was prescribed with an anomaly-persistent method that considers seasonality of sea ice. Ensemble hindcast experiments starting at 1st of November for the period 1999~2000 were performed and the predictability gain from the imposed cryospheric informations were tested. Large potential predictability gain from the snow information was obtained over large part of high-latitude and of mid-latitude land as a result of strengthened land-atmosphere interaction in the modeling system. Large-scale atmospheric circulation responses associated with the sea ice concentration anomalies were main contributor to the predictability gain.