• Journal of the Korean Chemical Society
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• v.66 no.4
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• pp.323-332
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• 2022

The purpose of this study is to investigate the effects of science classes using smart devices that combine augmented reality (AR) and virtual reality (VR) on the scientific attitude of middle school gifted students. In addition, it is intended to find out the perception of science classes using these smart devices. In addition to actual experiments, a science class program that allows students to experience science experiments virtually using AR and VR was applied to 15 middle school gifted students. Before and after the application of the program, the questionnaire is to investigate the interest in scientific classes, the attitude toward science exploration, and the professional interest in science, and the recognition of classes that combine AR and VR. In addition, through in-depth interviews, the perceptions of gifted students was accurately investigated. As a result of this study, the content of science classes and instructors showed high class satisfaction, but the smart devices and applications used during the science classes showed lower class satisfaction than others. As a result of comparing and analyzing the pre-post of gifted students, interest in science class, attitude toward science inquiry, and professional interest in science increased significantly among the sub-areas of the scientific attitude test. As a result of analyzing free responses and indepth interviews, gifted students responded with the advantage that classes using smart devices that combine AR and VR can be tested quickly and safely for a short time compared to actual experiments. On the other hand, they responded with low completeness of the application and dizziness when operating virtual reality. Based on this, implications for the development of applications and instructional programs using advanced technologies that can experience realistically limited scientific experiments such as experimental preparation, class time, and risk factors were obtained.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.2
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• pp.94-99
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• 2010

The purpose of this study was to examine the soft tissue changes in skeletal class II patients after mandibular advancement by bilateral sagittal split ramus osteotomy (BSSRO). In Asian population, the incidence of skeletal class II malocclusion is lower than that of skeletal class III malocclusion unlike the caucasians. This study was conducted to figure out the ratio at which hard tissue and soft tissue changes after mandibular advancement by analyzing cephalograms of 13 patients that have undergone the mandibular advancement surgery. As a result, change ratios of Li, B', Pog' according to the movement of li, B, Pog were found to be 0.59, 1.06, 0.82. Also, vertical height of vermilion zone (Si-Vb) and lower lip and chin (Si-Me') were measured to evaluate vertical changes. Vermilion zone showed tendency to decrease by 1.02 mm on the average postoperatively, whereas vertical length of lower lip and chin showed tendency to increase by 3.57 mm on the average.

• Journal of the Korean Society of Safety
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• v.32 no.5
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• pp.88-95
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• 2017

As the safety fields are expanding to a variety of industrial fields, safety technology has been developed by convergence between industrial safety fields such as mechanics, ergonomics, electronics, chemistry, construction, and information science. As the technology convergence is facilitating recently advanced safety technology, it is important to explore the trends of safety technology for understanding which industrial technologies have been integrated thus far. For studying the trends of technology, the patent is considered one of the useful sources that has provided the ample information of new technology. The patent has been also used to identify the patterns of technology convergence through various quantitative methods. In this respect, this study aims to identify the convergence patterns and fields of safety technology using association rule mining(ARM)-based patent co-classification(co-class) analysis. The patent co-class data is especially useful for constructing convergence network between technological fields. Through linkages between technological fields, the core and hub classes of convergence network are explored to provide insight into the fields of safety technology. As the representative method for analyzing patent co-class network, the ARM is used to find the likelihood of co-occurrence of patent classes and the ARM network is presented to visualize the convergence network of safety technology. As a result, we find three major convergence fields of safety technology: working safety, medical safety, and vehicle safety.

• Journal of Korean Elementary Science Education
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• v.34 no.1
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• pp.32-45
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• 2015

The purpose of this study is to further develop the strategies using EBS clipbank service and investigate the their effects of the science academic emotion on the student's attitude toward science. Clipbank is service for educational purpose. EBS provides clipbank that holds about 210,000 video clips made from EBS programs. Two class of 6th grade were selected and instructed. Implementing and using the teaching strategies, a test was administered to examine the science academic emotion of the students effects using clipbank teaching. It had two rounds for inspection about operation of the strategies with curriculum. In the second research, by re-supplying a more sophisticated program strategy from first in putting feedback. The result of analyzing the test was as follows. First, elementary teachers can be used in class to take advantage of a variety of educational materials clipbank contents. Result of teachers survey, clipbank teaching was effective and teachers who using clipbank service will be the continue utilize clipbank. Second, the strategy for using clipbank teaching was effective on student's science academic emotion. And strategy was effective significantly different depending on gender. In conclusion, the strategy for using clipbank teaching, made students feel that learning science was interesting. A lot of reseaches give that science can provide the ideas as a metheod to educational web-sites, educational web-sites can provide creative ideas to science learning strategy, but it is still lacking that research can be applied to education specifically on how to. This study will help elementary teachers adjust teaching to help students learn science with positive emotions.

• Journal of Science Education
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• v.40 no.1
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• pp.90-102
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• 2016

Flipped learning is generally designed to allow students to learn on their own in advance with the help of scaffolding material such as videos and text, and in the classroom, it is operated with the help of a teacher while the class is being learner-centered. For flipped learning, each of the teachers has to design the class, collect information, and prepare for scaffolding material, so they get to face a lot of difficulties spending much time to reorganize the curriculum and produce a video and so on. Accordingly, this researcher has developed flipped learning textbook models applicable to science class by analyzing Korean and overseas textbooks, conducting an in-depth interview to six science teachers practicing flipped learning, and also developing and applying the science textbook sample model. The elementary, middle, and high school science textbook models developed include not only the textbook-based model with no videos presented in advance but also the lecture-type model, experiment-based model, and inquiry and research-based model to realize flipped learning. This study is expected to present crucial implications to develop textbooks and science class as a class to perform learner-centered inquiry activity.

• Journal of The Korean Association For Science Education
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• v.34 no.3
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• pp.261-272
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• 2014

In this study, to disseminate the Practical On-site Cooperation Model (POCoM) for practical improvement of science teaching and learning through cooperation between researcher and teacher, an in-service program has been developed, applied and evaluated. The in-service program emphasizes the following three aspects; (1) video-recording of actual science teaching has been used as a primary resource, (2) communication between teacher and researcher and among teachers have been emphasized, (3) activities have been mainly included. The in-service program has been implemented for nine hours, and 17 science teachers have been recruited as volunteers. The result shows that, by checking the agreements between raters, we found that teachers' expertise in analyzing the science class using the Korean Teaching Observation Protocol (KTOP) has improved, and we have confirmed that teachers are able to judge whether the science class has improved or not. Through the questionnaire, various highly positive responses could be obtained from teachers. And through the observation of teachers' activities during the in-service program, teachers' questions, their difficulties in doing activities, and their comments for improving the program has also been analyzed. Finally, based on the results, a list of recommendations for a more effective in-service program have been suggested. It is expected that this list can be utilized for more effective and meaningful design and implementation of in-service course.

• Communications of the Korean Mathematical Society
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• v.26 no.2
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• pp.321-338
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• 2011

In this paper, a class of delayed epidemic model with diffusion is investigated. By analyzing the associated characteristic transcendental equation, its linear stability is investigated and Hopf bifurcation is demonstrated. Some explicit formulae determining the stability and the direction of the Hopf bifurcation periodic solutions bifurcating from Hopf bifurcations are obtained by using the normal form theory and center manifold theory. Some numerical simulation are also carried out to support our analytical findings. Finally, biological explanations and main conclusions are given.

• Journal of the Korea Safety Management & Science
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• v.15 no.1
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• pp.21-30
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• 2013

Korean Volunteer Fire Departments are the representative disaster-related civilian organizations which are based on "Firefighting Framework Act Article 37"and ordinance for complementing the lack of fire-fighting personnel and volunteer and they play a part as community safety keepers. They are operated by the National funding, but cannot be defined as the organization in governmental sources completely or pure volunteer organization in terms of its founding purpose and activities. In these special characteristics, some Volunteer Fire Departments play an important role in Civilian Volunteer Disaster Prevention by being managed effectively, but the others do not. There can be many cause-analyses about this difference. They aren't profit-making organizations and are groups which have no compulsion. So it is important that who the leader is, and what type of leadership he has. By solving this bias by considering these characteristics, in this study we make them perform the center role of community safety network through analyzing the existing status and problems of volunteer fire department education and customized training program reengineering to meet class-specific and regional level.

• Journal of Mechanical Science and Technology
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• v.17 no.7
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• pp.966-977
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• 2003

This paper investigates how intentional mistuning of bladed disks reduces their sensitivity to unintentional random mistuning. The class of intentionally mistuned disks considered here is limited, for cost reasons, to arrangements of two types of blades (A and B, say). A two-step procedure is then described to optimize the arrangement of these blades around the disk to reduce the effects of unintentional random mistuning. First, a pure optimization effort is undertaken to obtain the pattern (s) of the A and B blades that yields small/the smallest value of the largest amplitude of response to a given excitation in the absence of unintentional random mistuning using Genetic Algorithm. Then, in the second step, a qualitative/quantitative estimate of the sensitivity for the optimized intentionally mistuned bladed disks with respect to unintentional random mistuning is performed by analyzing their amplification factor, probability density function and passband/stopband structures. Examples of application with simple bladed disk models demonstrate the significant benefits of using this class of intentionally mistuned disks.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.3
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• pp.932-940
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• 2017

This study investigated the perception of pre - service teachers in order to find out how paper textbooks are used in high school classes and what improvement is needed. Firstly, the results of analyzing the perception about the utilization of textbooks are as follows. First, in the case of Korean language, social studies, mathematics, science, and English, textbooks were used most frequently, and most of the respondents did not use textbooks for arts and physical education subjects. Secondly, Korean language, social studies, mathematics, science, and English textbooks are most frequently used as teaching materials. Third, in the case of Korean, social, mathematics, science, and English subjects, in addition to textbooks, problem collections were used most frequently and arts and physical education subjects showed the most use of prints. Next, the results of analyzing the perception of the improvement method of the textbooks are as follows. First, in the high school class, the response rate was high in that Korean, social, mathematics, science, and English classes needed a textbook. Most of the respondents answered that they were not necessary for the textbooks of arts and physical education subjects. Second, in order to improve the textbooks, the most demanding textbooks focused on the core basic contents, followed by self - directed learning activities, competency centered contents selection, cooperative learning activities, and teacher self - development. The demand for digital textbooks was low.