• Journal of Practical Engineering Education
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• v.13 no.2
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• pp.327-332
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• 2021

Materials used for education include SM20C, Al6061, and acrylic. SM20C materials are used a lot in certification tests and functional competitions as carbon steel, but they are also used in industrial sites. Al6061 is said to be a material that produces a lot of tools because it has lower hardness than carbon steel and is highly flexible. When practical guidance is given to students using acrylic materials, it is a material that causes vibration and tool damage due to excessive cutting. In this process, we examine how impact on the 5-axis equipment 2NC head can affect precision control. The weakest part of a five-axis equipment is the head that controls the AC axis. In the event of precision and cumulative tolerances in this area, the precision of all products is reduced. Thus, a key part of the 2NC head, the spindle housing was carried out using Al7075 T6 (U.S. Alcoasa) material and the entire body using FCD450 (spherical graphite cast iron). In the vibration and cutting process acting on these two materials, the analysis was carried out to determine the value of applying the force as a finite element analysis under extreme conditions. We hope that using these analytical data will help students see and understand the structure of 5-axis machining rather than 5-axis cutting.

• Journal of Science Education
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• v.45 no.2
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• pp.143-155
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• 2021

The goal of this study is to examine the Integrated Science and Science Laboratory Experiments of the 2015 revised curriculum applied since 2018, and to explore ways to improve these two subjects in preparation for the 2022 revised curriculum. A survey was conducted by randomly sampling high schools across the country, with a total of 192 science teachers participating. In addition, 12 high school science teachers were selected as focus group, and in-depth interviews were conducted to investigate ways to restructure common science courses for the next curriculum. Main research results include that most schools were operated in 6~8 units for Integrated Science, and the teachers in charge of Integrated Science per class averaged 2~3 over the three years. For Science Laboratory Experiments, it has operated for a total of two semesters, one unit per semester, and it was found that several science teachers are in charge of Science Laboratory Experiments to fill the insufficient number of hours regardless of major. In the in-depth interview, science teachers argued that Integrated Science should be reduced and restructured by strengthening key competencies in preparation for the high school credit system. Based on the research results, ways to reorganize Integrated Science focused on big ideas, ways to construct common science courses based on fundamental science concepts that can guide elective courses, the necessity of career guidance through common science courses, and the necessity of strengthening teacher professionalism for teaching interdisciplinary and multidisciplinary subjects were suggested.

• Journal of Plant Biotechnology
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• v.47 no.4
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• pp.261-272
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• 2020

Approvals for cultivation and import of genetically modified (GM) crops have dramatically increased around the world. Comparative compositional studies are an important aspect of safety assessments of products from GM crops and are based on substantial equivalence. Compositional analyses focus on determining similarities and differences between the compositions of the GM crops and their conventional counterparts, and thereby assessing the compositional equivalence of GM crops and their conventional comparators. The analytes, such as major constituents, key nutrients, and antinutrients, are generally determined on a crop-specific basis according to the OECD consensus document. The use of standard methods throughout the processes, such as selection of comparators, field trials, analytical methods, and statistical data analysis, is crucial. In this study, we showed the general framework of compositional studies. Literature for compositional studies of GM crops conducted abroad and in Korea was reviewed to obtain information about analytes, conventional counterparts, cultivation year, location, and statistical methods. The studies conducted abroad assessed for commercial release of GM crops such as soybean, maize, and cotton, while domestic studies were mainly performed for research in rice. In addition, we suggested a guidance for conventional comparators and field trials applicable to the domestic situation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.2
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• pp.151-159
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• 2021

Cost information in the Korean construction industry is mainly controlled by the government agencies. However, there have been wild-spread speculations among participants on the adequacy of these unit prices and difference with the actual market condition. Korean public-led unit prices are developed using mainly a top-down approach by a few designated public institutions. Due to the rapid fluctuations in market prices and high-volume of information, it is impossible for a few public institutions to properly consider market conditions. However, there are almost none private cost reference while many are available in other countries to supplement the public cost references. Needs for private cost references have recognized, and this study can be seen as a pilot study to support them. This study attempts to identify the problem areas of Korean cost references and to provide guidance by benchmarking other countries. This study has confirmed the need of developing market-driven cost references by employing a bottom-up approach in which a large number of various construction participants are fostered to provide their own cost information and share with others. It is envisioned that this study provides foundations for further study on the development on-line construction market platform based on abundant and appropriate cost information.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.5
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• pp.114-126
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• 2021

This paper compared bridge maintenance in United Stated, United Kingdom, Japan, and Korea. Bridges play an essential role in transportation network and in the economic production process. To provide a desirable level of service to the public within limited budgets, it is required to provide effective bridge maintenance activities (e.g. inspection and repair/rehabilitation) at acceptable level of bridge service. A number of bridges are expected to age rapidly in Korea, which will be the excess burden of government. Since several countries have experienced a number of deteriorated bridges because of aging, the countries aforementioned in this study have already developed comprehensive bridge maintenance programs such as inspection practice and repair/rehabilitation techniques. Therefore, the goal of this paper is to synthesize and to compare useful knowledge on bridge maintenance and bridge crack repair/restoration of deteriorated concrete bridge in the four countries. Finally, recommendations that will serve as guidance to transportation agencies for potential enhancements to bridge maintenance and bridge repairs are presented.

• Communications of Mathematical Education
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• v.35 no.4
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• pp.475-504
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• 2021

This study is a study that developed class materials that can be applied directly to classes by field teachers in consideration of ' research on the development is valuable as a field support study.', 'In material development, organizing data centering on the knowledge composition and inquiry activities of characters related to the mathematics concept can help develop class materials', and 'The fact that the development of subject data for has been insufficient'. To this end, this study went through the procedure of 'establishing a data development plan, data development, verifying field teachers on development data, verifying subject experts on development data, and developing final data reflecting verification opinions.' Therefore, based on the 1st 50 minutes reflecting the task exploration model, it was possible to develop class materials for the 3rd time. In this study, development data were presented with a 17-week curriculum plan, a class guidance plan that presents teacher-student interaction, and a task development form that students fill out and submit in class. This study was developed with the developed data in mind to be applied to actual classes. Therefore, a follow-up study is needed to apply the developed data to actual classes and analyze the results.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.386-395
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• 2021

The purpose of this study was to confirm the relationship between positive psychological capital, professor support, and the career preparation behavior of college students, and to identify the factors influencing the career preparation behavior. The convenience sampling method was used on 180 students from August 30 to October 30, 2020, Data was collected using a structured questionnaire and analyzed by frequency, percentage, mean, standard deviation, t-test, ANOVA, Scheff test, Pearson's Correlation Coefficients, and multiple regression. The research results showed that there were significant differences in positive psychological capital and professor support according to gender, majors, and economic levels. There were significant differences in career preparation behavior according to gender (t=3.52, p<.001), major (F=10.85, p<.001), and career decision (t=4.98, p<.001). There were significant differences in career preparation behavior according to gender, majors, and career decisions. Positive psychological capital (r=.45, p<.001) and professor support (r=.40, p<.001) showed a positive correlation with career preparation behavior. Factors influencing career preparation behavior were majors, career decisions, positive psychological capital, and the explanatory power of these factors was 32.5%. Therefore, effective career and counseling guidance should be planned to increase positive psychological capital according to the major. It is necessary to provide opportunities for exploration of various career options to enable students to select suitable careers or jobs and to set goals, and provide an environment with positive motivation.

• The Journal of the Korea Contents Association
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• v.21 no.7
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• pp.59-70
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• 2021

This paper studies and analyzes the effect of illustrations in picture books on time representation with fictional picture books as the study scope. In this paper, the time type of picture books can be divided into time point, timeline and time rhythm, referring to case analysis from time symbolic elements, picture layout and picture sequence respectively. First of all, time symbolic elements are referred to the time point and time rhythm. The materialized time symbolic element is things that can directly represent time and trigger associations with time; the color symbolic element means the color changes in the real world within a certain time; the contrast of light and shadow corresponds to the changes in a day. Fast-moving objects will be presented with dashed or blurred lines, while static, stable and slow objects will be depicted with solid lines. Secondly, the picture layout of illustrations in picture books is suitable for representing the content of the timeline and describing the sequence or causality of events. Finally, the picture sequence can represent the timeline, time rhythm and "synchronicity". It will make use of visual logic to win readers' trust in time information expressed in pictures, and then follow and connect viewpoints on the basis of adapting to reading habits. The essence of time representation in picture books is to express time by space, and use different combinations of elements in space and visual guidance to convey time information.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.83-89
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• 2021

This study examined how the learning styles and emotions of 234 students enrolled in early childhood education-related departments affected their ability to participate in the learning community. The research collected the variables of the pre-service early childhood teachers' ability to participate in the learning community, the emotions that they experienced while learning, and their learning styles. The collected data were analyzed through correlation analysis and regression analysis. The results indicate that the students' ability to participate in the learning community was positively correlated with the following: their analytical learning attitude (among learning styles); learning motivation; degree of preference for discussion and discussion types; positive and negative emotions, which are subcategories of learning emotion; and the degree of preference for experimentation and their practice type among teaching methods. Second, regression analysis showed that the students' ability to participate in the learning community could be predicted by negative emotion as a subcategory of their learning emotion, learning motivation, degree of preference for the experiment and practice type, their analytical learning attitude, and the degree to which students value studying the content of their major subjects.

• Journal of Korean Medicine Rehabilitation
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• v.31 no.3
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• pp.95-104
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• 2021

Objectives The purpose of this study was to observe effectiveness of ultrasound-guided Soyeom pharmacopuncture therapy at acromioclavicular joint of shoulder in patients with anterior shoulder pain. Methods We analyzed medical records of 9 patients hospitalized with anterior shoulder pain who had admitted to Department of Korean Rehabilitation Medicine, College of Korean Medicine, Daejeon University from March 1, 2021 to June 13, 2021. 9 patients were treated the treatment of Soyeom pharmacopuncture therapy on acromioclavicular joint under ultrasonic guidance with Korean medicine treatment (such as herbal medicine, acupuncture, moxabustion, etc). The study was conducted as a retrospective observation study which analyze the patient's medical records. We used numeric rating scale (NRS) to evaluate pain reduction and the shoulder range of motion (ROM) to evaluate function improvement twice (before pharmacopuncture treatment and 5 days later treatment). Statistical analysis was performed using the IBM SPSS Statistics version 25 program (IBM Co., Armonk, NY, USA). Results The average of numeric rating scale reduced statistically significantly from 5.56±1.13 to 3.11±1.36 (p=0.004). The average of shoulder flexion ROM increased statistically significantly from 166.67±8.17° to 175.00±8.37° (p<0.05). And the average of shoulder abduction ROM increased statistically significantly from 158.57±20.35° to 172.86±12.53° (p<0.05). Both NRS and shouler ROM showed statistically significantly improve after treatment. Conclusions This study shows ultrasound-guided Soyeom pharmacopuncture therapy at acromioclavicular joint of shoulder has a meaningful clinical effect on the improving shoulder pain and ROM especially on flexion and abduction.