• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.575-584
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• 2021

The critical low temperature and response of the behavioral tolerance of red sea bream Pagrus major fingerlings were determined using the continuous behavior monitoring system (CBMS). The behavior of the experimental organisms was observed by decreasing the water temperature by 2.0℃ and 4.0℃ every 12 hours and 24 hours in the range of 8.0-20.0℃. An unstable behavior pattern was observed in red seabream fingerlings exposed to water temperatures below 12.0℃, in which the swimming activity decreased and repeatedly stopped, regardless of the exposure time and water temperature fluctuation. The swimming ability of the organisms exposed to 8.0-10.0℃ decreased sharply, and the behavior of staying at the bottom of the test tank was observed. Only 50 % of the organisms survived due to the low-temperature stress, and all individuals died within six hours after the cold shock. In addition, the behavior index (BI) decreased rapidly, and the amplitude change of the coefficient of variation (CV) was found to have a greater variation than the other water temperatures (p<0.05). Low-temperature stress of red sea bream is promoted at 12.0℃, and it is interpreted as the tolerance limit, which can induce a sublethal response of the organisms exposed to cold shock of 8.0-10.0℃.

• Journal of Navigation and Port Research
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• v.44 no.6
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• pp.509-516
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• 2020

Korea has gradually been developing port distriparks in major domestic trade ports to diversify their function and create added-value. New tenant companies are needed to help achieve these goals, but no research has been done on selection criteria. To provide such criteria, this study conducted a comparative analysis of the productivity of tenant companies in Busan New Port Distripark based on their characteristics. SFP (single-factor productivity) was measured using the operational data of 67 companies in the distripark over the past - three years (2017-2019). The results indicate that the logistics business and the manufacturing business have strengths in cargo volume productivity and in sales productivity respectively. Also, Northern distripark, a relatively older facility, was found to be more productive than Ung-dong distripark. Finally, the effect of investment-both foreign and in FAC/EQ (facility and equipment)-on productivity showed an inverse relationship with productivity, with the companies with under-average investments being more productive than those whose investments were above average. Therefore, to enhance the productivity and competitiveness of port distriparks, tenant companies must be subject to supplemented system and law for increasing employment and cargo volume, and reestablished selection criteria.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.19-26
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• 2021

The lattice structure is attracting attention from industry because of its excellent strength and stiffness, ultra-lightweight, and energy absorption capability. Despite these advantages, widespread commercialization is limited by the difficult manufacturing processes for complex shapes. Additive manufacturing is attracting attention as an optimal technology for manufacturing lattice structures as a technology capable of fabricating complex geometric shapes. In this study, a unit cell was formed using a three-dimensional coordinate method. The relative density relational equation according to the boundary box size and strut radius of the unit cell was derived. Simple cubic (SC), body-centered cubic (BCC), and face-centered cubic (FCC) with a controlled relative density were designed using modeling software. The accuracy of the equations for calculating the relative density proposed in this study secured 98.3%, 98.6%, and 96.2% reliability in SC, BCC, and FCC, respectively. A simulation of the lattice structure revealed an increase in compressive yield load with increasing relative density under the same cell arrangement condition. The compressive yield load decreased in the order of SC, BCC, and FCC under the same arrangement conditions. Finally, structural optimization for the compressive load of a 20 mm × 20 mm × 20 mm structure was possible by configuring the SC unit cells in a 3 × 3 × 3 array.

• (The)Korea Educational Review
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• v.23 no.2
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• pp.31-53
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• 2017

Drawing upon Vygotsky's theory, this paper explores the possibilities of imaginative education and those implications in relation to emotions. Imagination is an important element of future competencies as well as creativity. But there is a big dilemma in an educational intervention about imagination. If imagination is naturally occurring and therefore considered a mysterious ability that is specific to a child, education should not intervent as much as possible so that it can be expressed and preserved. It is linked to Piaget's influence, which regards imagination as a mental immaturity of childhood. Vygotsky who is a developmental psychologist argues that mind is generated from the socio-cultural origins in opposition to Piaget's spontaneous generation and emphasizes that it is a core characteristic of human to create something through interaction with the world. Vygotsky consider that 'imagination' which synthesizes empirical material and creates a new image is a key factor in human creativity. He reminded us of the possibilities and importance of imaginative education by revealing that imagination is not limited to childhood but constantly develops through cultural experience. Especially Vygotsky's understanding has important implications for future education in relation to emotion. Imagination plays a role of expressing and dealing with human emotions. Unlike the reason-centered society in the past, future society demands a big role of imagination in education for dealing with emotional knowledge and morality.

• (The)Korea Educational Review
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• v.23 no.1
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• pp.5-33
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• 2017

The purpose of this study is to analyze leading teachers' opinions on key competencies and subject competencies presented in the 2015 revised national curriculum and to draw implications for competency-based curriculum development and implementation. The research findings show that leading teachers are generally positive about the introduction of key competencies, subject competencies setting and its feasibility and recognize that the key competencies are highly related to the subject competencies of each subject. However, it is judged that the key competencies and subject competencies are not embodied well in every aspect of the curriculum documents. They also recognize that in the practice of competency education, supporting the development of teachers' ability to conduct student-centered classes in a culture that enables voluntary research efforts of the teacher community can be the biggest issue rather than external support such as development of competency-centered textbooks or consulting and supervision. Finally, we propose the need for support and policy that enable voluntary efforts for interdisciplinary cooperation and strengthening teacher capacity rather than developing competency-centered textbooks; specification of competency education in educational content, pedagogical methods and assessment; reconsideration of subject competencies setting; maintaining the relationship between key competency and items that guide educational goals.

• The Journal of the Korea Contents Association
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• v.20 no.12
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• pp.555-566
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• 2020

The Purpose of this study is to examine the effect of emotional intelligence, resilience, and communication style on stress coping in college students. The research problems were verified by correlation analysis and multivariate regression analysis. A questionnaire survey was conducted on 303 college students. The findings are as follows. First, college students who have high emotional intelligence show more problem-focused coping and social-support seeking coping in stressful conditions. Particularly, it is found that managing emotion in emotional intelligence has the greatest effect on problem-focused coping and social-support seeking coping, using emotion influences emotion-focused coping. Second, college students who have high resilience are also found more problem-focused coping and social-support seeking coping in stressful conditions. Especially it is found that controllability has the greatest effect on problem-focused coping, positivism influences wishful thinking coping. Similarly, sociability influences social-support seeking coping and emotion-focused coping. Third, those students who was androgynous with high assertiveness and responsiveness used more frequently the problem-focused coping, those who was feminine with high responsiveness used more frequently the social-support seeking coping and wishful thinking coping.

• The Journal of Sustainable Design and Educational Environment Research
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• v.19 no.4
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• pp.26-39
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• 2020

This study analyzed the usage characteristics and requirements of students who are users of the middle school education space, and the following results were obtained: First, we could see that various types of classes were needed, such as lecture-style classes, team projects, and four-person consultation and discussion classes, in a way that helped to improve the desirable teaching patterns and learning ability. Second, the place where space was used during the break and the relationship between peers, revealed that most of them were in the classroom and the hallway, and the peer group was composed of three to eight people or more, that were active with various compositions. Third, a gym, library, toilet, stairway, cafeteria, nurse's office, and teachers' room appeared in the center of the building, indicating the need for a balanced layout. Fourth, physical education (dance) rooms, audiovisual rooms (performance rooms), workshops (personal creation), snack bar, rest area, spacious indoor square, and study rooms were needed as facilities that can help learning activities other than current facilities. These outcomes show that the existing classroom layout and space composition formats require some spatial restructuring.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.1
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• pp.59-69
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• 2021

Recently, large-scale offshore and coastal structures have been constructed owing to the increasing interest in eco-friendly energy development. To achieve this, precise simulations of waves are necessary to ensure the safe operations of marine structures. Several experiments are required in the field to understand the offshore wave; however, in terms of scale, it is difficult to control variables, and the cost is significant. In this study, numerical waves under various wave conditions are produced using a piston-type wavemaker, and the produced wave profiles are verified by comparing with the results from a numerical wave tank (NWT) modeled using the smoothed particle hydrodynamics (SPH) method and theoretical equations. To minimize the effect by the reflected wave, a mass-weighted damping zone is set at the right end of the NWT, and therefore, stable and uniform waves are simulated. The waves are generated using the linear and Stokes wave theories, and it is observed that the numerical wave profiles calculated by the Stokes wave theory yield high accuracy. When the relative depth is smaller than two, the results show good agreement irrespective of the wave steepness. However, when the relative depth and wave steepness are larger than 2 and 0.04, respectively, the errors are negligible if the measurement position is close to the excitation plate. However, the error is 10% or larger if the measurement position is away from the excitation location. Applicable target wave ranges are confirmed through various case studies.

• Journal of the Korea Convergence Society
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• v.12 no.8
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• pp.267-277
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• 2021

This study was done with collected and analyzed data using the convenient sampling method on 349 middle school students located in the metropolitan area in order to verify the effect of instructors verbal and nonverbal communications on instructor trust and class commitment in middle school sports clubs. As a result of analyzing the collected data, First, as a result of correlation analysis using the total number of items between sub-factors of latent variables, all correlation coefficients showed a positive (+) significant relationship. Second, as a result of the effect of verbal and nonverbal communications on instructor trust, it was found that the influence of spatial language, appearance language, body language, and linguistic factors were significantly explained in order. Third, as a result of the effect of verbal and nonverbal communications on class flow, it was found that class commitment was significantly explained in the order of appearance language, spatial language, and linguistic factors. Fourth, as a result of the influence of instructor's trust on class commitment, it was found that only the exercise capacity factor significantly explained class commitment. This study provides basic academic data to plan and create interactions with school sports club instructors and students.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.4
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• pp.231-241
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• 2021

Although the deterioration of bridges may occur due to various causes, one of the representative causes is that the chloride used for deicing in the winter penetrates bridge members and results in corrosion. This study aims to quantify the ageing degree resulting from the corrosion of a bridge, apply it to the inelastic dynamic analysis model of the bridge, perform a seismic fragility analysis, and evaluate the relationship between the ageing degree and the seismic fragility curve. It is important to appropriately define the threshold values for each damage state in seismic fragility analyses considering the ageing degree. The damage state was defined using the results of existing experimental studies on the characteristics of the deterioration in the displacement ductility capacity of the pier, according to the ageing degree. Based on the seismic fragility analyses of six types of bridges divided by three types of bearing devices and two pier heights, it was found that the seismic vulnerability tends to increase with the ageing degree. The difference in seismic vulnerability with respect to the ageing degree exhibits a tendency to increase as the damage state progresses from slight to moderate, severe, and collapse.