• Applied Chemistry for Engineering
• /
• v.22 no.5
• /
• pp.453-460
• /
• 2011

Recently, there is growing interests in the application of supercritical fluids for food and medical fields since supercritical fluids ($CO_2$ and $N_2O$) have known to be safe and effective as a non-thermal sterilization technique. Although supercritical fluids have been investigated for various kinds of products, they have not yet been used in common currency due to their lack of knowledge related to the antimicrobial activity or detailed mechanisms. In this review paper, we summarized the characteristics, antimicrobial activity and mechanisms, important factors, and applicability of supercritical fluids to help the investigation and commercialization of supercritical fluids sterilization technique.

• The korean journal of orthodontics
• /
• v.26 no.1 s.54
• /
• pp.95-104
• /
• 1996

This study was undertaken to investigate the correlations bite force and the electromyographic activities of masticatory muscle in deepbite, using the T-Scan system and electromyograph. The subjects of this study consisted of two groups ; one of 20 individuals with normal occlusion, the other group of 30 with deepbite. The deepbite was composed of Class I deepbite(male 9, female 7) and Clas II div. 1 deepbite(male 8, female 6). The obtained results of this study were as follows : 1. The maximum bite force was 155.93 N in normal occlusion, 165.11 N in Class I deepbite group, 111.55 N in Class II div. 1 deepbite group. 2. The greater !he number of tooth contacts, the more the bite force increased in all groups. 3. During maximum clenching, masseter and ant. temporailsmuscle activity of normal and Class I deepbite group were significantly higher than that of Class II div. 1 deepbite group, and the activity of masseter muscle was higher than that of ant. temporalis muscle in all groups. 4. The greater the maximum bite force, the more the muscle activities increased in all groups.

• Journal of the Korean Society of Earth Science Education
• /
• v.7 no.1
• /
• pp.1-10
• /
• 2014

The purpose of this study is to introduce the science-play in the regular class, stimulate the student's curiosity, motivate them and take active part in their science class. To make an effective science class, we developed the science-play activity instead of experiments in the text, and applied it to the class. The experimental group has statistically meaningful results in the science process skills, expecially in subordinate elements such as observation, deduction, expectation, data analysis and assumption establishments(p<.01). However, the comparative group has no meaningful results in the science process skills. Though the average value of the science related attitude in the experimental group had only a little increase and had no statistically meaningful results, that in the comparative group has decreased during the same period. As for the experimental group, the science-play activities were repeated and their science related attitude has increased a little. Even though there were no meaningful statistic results(p>.05), the science-play activity was effective in the science related attitude. As a result of this research, it could be said that the science-play activity can improve the student's science process skills and the science related attitude, and the science-play program should be further developed and applied to make easy and effective science classes.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
• /
• v.9 no.5
• /
• pp.259-271
• /
• 2019

The purpose of this study is to examine the potential of flip learning in Korea and to explore the possibilities of university English education. To this end, participants are sought for classes wherein general English class is taught and the researcher is in charge of teaching. 25 students of media-English class is chosen for the study. Instruments for the study include class evaluation and feedbacks, mid-term and final exams, group performative evaluation, on-line class views and participations. The findings of the study are: As students progress in flipped learning classes, their exam results significantly improved, and their performative evaluation results also improved significant across different groups. The effects are more eminent among higher levels of students, but students with mid and low level of English still improved significantly once they engage themselves in preview activity on a regular basis and self-directedly.

• Journal of Engineering Education Research
• /
• v.25 no.6
• /
• pp.69-80
• /
• 2022

In this study, the application of flipped learning methodology to thermodynamics in mechanical engineering was examined, and how university students view flipped learning and the effects of flipped learning were analyzed. To analyze the effects of flipped learning, pre-class survey, assessment on learning in pre-class, team activities during class, and post-class survey were conducted. The analysis was also conducted on 33 students who took the thermodynamics course in mechanical engineering, and the PARTNER flipped learning model was applied to the class. The results of this study are as follows; In the preliminary survey, the students expected that the flip-learning class with team activities and teaching between team members would be helpful in improving their learning. In addition, students recognized that cooperative learning through a team was helpful for learning. The case reflecting the result of pre-learning evaluation to the subject grades showed higher pre-learning evaluation results than the case not reflecting the result of the pre-learning evaluation to the subject grades, and it was found that the pre-learning evaluation was acting as a factor to promote learning in pre-class. In post-class survey, the satisfaction with the flipped learning class was high, indicating that the effectiveness of the flipped learning class applied to the thermodynamics class was excellent.

• Journal of Engineering Education Research
• /
• v.23 no.6
• /
• pp.68-76
• /
• 2020

This study presents a teaching model to increase the participation and interest, and to improve their understanding of physical concepts of first-year engineering students taking physics(2) course at a three-year college. In the class, a team task solution based on teamwork and a peer learning method through questions and answers between participants in each team were applied so that learners could actively participate in the class to discuss and present. We examined how the activities of each team affected students' interest in subjects, motivation to learn, and the degree of understanding of physical concepts. In the team activity, students were able to actively participate through emotional sharing between learners and free questions and explanations, and it was confirmed that academic achievement was improved by comparing the final exam evaluation results with the evaluation results of the previous three years.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2022.11a
• /
• pp.63-64
• /
• 2022

In this study, the quality of mineral admixture, Comparison of blast-furnace slag(BS) and fly ash(FA)in Korea and China. In the case of BS, Korea is mainly classified into 1 type to 4 types according to the specific surface area, whereas China is classified into S105, 95, and 75 according to the activity index of 28 days of age. In the case of FA, Korea is like BS, is mainly classified into types 1 to 4 according to specific surface area, whereas China is classified into F, C (class F, class C) by ingredients and class I, II, and III according to powder and ignition loss.

• Journal of Engineering Education Research
• /
• v.20 no.2
• /
• pp.39-49
• /
• 2017

This research aims to explore the relationships between 'teamwork skills' (often called team activity competence) and 'thinking styles' of engineering students in Korea, and to provide an explanation for the application of team-based environment as well as for the increase of teamwork skills. Teams and team activity are pervasive in today's organization and there has been relatively much research on teamwork skills and its related factors. However, to date, little attention has been paid to the teamwork skills, essential factor in team-based environment and its relationships with thinking styles. This study was conducted with 383 engineering students at P University, and students' teamwork skills as well as thinking styles have been measured before and after team-based learning class (hereafter TBL). Our findings show that firstly, there was a significant increase of teamwork skills between before and after TBL class. Second, team activity competence was found to have a higher correlation with most of creativity generating styles (i.e. legislative, judicial, hierarchical and global styles). Third, hierarchical style was found to influence team activity more than other components, and also legislative, external, global and judicial styles contributed to team-based activity. These findings are expected to provide an explanation for the application of thinking styles in team-based environment and will be useful for the improvement of related courses in engineering school.

• Journal of Korean Elementary Science Education
• /
• v.31 no.3
• /
• pp.311-320
• /
• 2012

The purpose of this study was to examine the effect of peer mentoring activity in elementary school. For this study, an experimental group was conducted for peer mentoring activity in science class. The mentoring team was organized by mento-mentee team according to the scores of science process skill and achievement. The objects of this study were the sixth grade of both an experimental group (28 students) and a control group (27 students) located in Incheon. The results of this study were as follows. First, the experimental group was shown more significant effect for improvement of science process skills than the control group (p<.05). As the result of analysis by groups, both of mento and mentee showed significant effect for improvement of science process skills. Second, the peer mentoring activity showed more significant effect for improvement of achievement (p<.05). As the result of analysis by groups, mentee showed significant effect for improvement achievement. But mento group didn't show significant effect. Third, the peer mentoring activity showed the effect for positive changes of scientific attitude. If matching the mentoring object effectively and conducting the classes applying peer mentoring activity based on the results of this study, it's expected to draw student' improvement of science academic, achievement and positive changes of scientific attitude.

• Korean Management Science Review
• /
• v.30 no.1
• /
• pp.15-24
• /
• 2013

We consider the single machine scheduling problem with a rate-modifying activity and time-dependent deterioration after the activity. The class of scheduling problems with rate-modifying activities and the class of scheduling problems with time-dependent processing times have been studied independently. However, the integration of these classes is motivated by human operators of tasks who has fatigue while carrying out the operation of a series of tasks. This situation is also applicable to machines that experience performance degradation over time due to mal-position or mal-alignment of jobs, abrasion of tools, and scraps of operations, etc. In this study, the integration of the two classes of scheduling problems is considered. We present a mathematical model to determine job-sequence and a position of a rate-modifying activity for the integration problem. Since the model is difficult to solve as the size of real problem being very large, we propose genetic algorithms. The performance of the algorithms are compared with optimal solutions with various problems.