• Journal of Korean Elementary Science Education
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• v.36 no.4
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• pp.346-355
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• 2017

The 2015 revised national science curriculum encourages students to cultivate the science core competencies such as scientific thinking, science process skills, scientific problem-solving ability, scientific communication skill, scientific participation and lifelong learning ability. To fill this purpose, we practiced science writing classes based on core competencies and examined the effect of its application. The target unit was 'weather and our life', 'acid and base', 'speed of an object', and 'structure and function of our body' in the fifth grade of elementary school. The results were as follows. First, it was proven that science writing activities based on core competencies did not help improving science process skills of learners. Second, it had a significant effect on the improvement of the learner's self-directed learning ability, in particular, owner spirit, meta cognition and information search. Third, this strategy for science writing changed learners' scientific attitude positively. The above-mentioned results show that this science writing classes can be applicable as one of effective methods in cultivating science core competencies.

• The Journal of Sustainable Design and Educational Environment Research
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• v.16 no.3
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• pp.37-50
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• 2017

The Ministry of Education selected and implemented 'science core school' since 2009 as a policy to strengthen science education to produce talented science students. This study judged that it is necessary to examine the current management practice and diagnose problems to propose improvement measures for more successful management of science core school in the future. To this end, we interviewed and observed teachers and students at a high school specialized in science based in Gyeonggi province which was selected as a science core school, as qualitative study methods such as interview and observation to survey and analyze the current management practice of the school. The management outcome was that the school contributed to fostering talented students in natural sciences and engineering because more varied activities were implemented at the school to develop scientific knowledge of students including experiment, excursion, and circle activity. Identified problems were increased amount of private education due to intense competition over school achievement, negligence of extracurricular activities, burdensome workload for teachers of specific subjects, and lack of expertise of math and science teachers. In conclusion, the following improvement measures are suggested for sustainable management of science core schools: greater liberty should be granted to science core schools; more training opportunities should be given to teachers; college admission program should be improved for science core school students; and it is necessary to introduce courses taught by external teachers, and provide systematic support such as increasing administration staff.

• Elastomers and Composites
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• v.51 no.4
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• pp.275-279
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• 2016

Additive manufacturing or 3D printing is a new manufacturing process and its application is getting growth. However, the product qualities such as mechanical strength, dimensional accuracy, and surface quality are low compared with conventional manufacturing process such as molding and machining. In this study not only mechanical characteristics of polymer sandwich panel having three dimensional core layer but also mechanical characteristics of core layer itself were analyzed. The shape of three dimensional core layer was pyramidal kagome structure. This core layer was fabricated by two different methods, injection molding with PP resin and material jetting type 3D printing with acrylic photo curable resin. The material for face sheets in the polymer sandwich panel was PP. Maximum load, stiffness, and elongation at break were examined for core layers fabricated by two different methods and also assembled polymer sandwich panels. 3D printed core showed brittle behavior, but the brittleness decreased in polymer sandwich panel containing 3D printed core. The availability of 3D printed article for the three dimensional core layer of polymer sandwich panel was verified.

• Nuclear Engineering and Technology
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• v.52 no.5
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• pp.937-946
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• 2020

The aim in the present work is to simulate accident scenarios of AP1000 during the small-break loss-of-coolant accident (SBLOCA) and investigate the performance and behavior of automatic depressurization system (ADS) during accidents by using MIDAC (The Module In-vessel Degradation severe accident Analysis Code). Four types of accidents with different hypothetical conditions were analyzed in this study. The impact on the thermal-hydraulic of the reactor coolant system (RCS), the passive core cooling system and core degradation was researched by comparing these types. The results show that the RCS depressurization becomes faster, the core makeup tanks (CMT) and accumulators (ACC) are activated earlier and the effect of gravity water injection is more obvious along with more ADS valves open. The open of the only ADS1-3 can't stop the core degradation on the basis of the first type of the accident. The open of ADS1-3 has a great impact on the injection time of ACC and CMT. The core can remain intact for a long time and the core degradation can be prevent by the open of ADS-4. The all results are significant and meaningful to understand the performance and behavior of the ADS during the typical SBLOCA.

• IEIE Transactions on Smart Processing and Computing
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• v.5 no.3
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• pp.169-177
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• 2016

To realize high-speed intrusion detection by accommodating many regular expression (regex)-based signatures and growing network link capacities, we propose the Service TimE-Aware Load-balancing (STEAL) algorithm. This work is motivated from the observation that utilization of a many-core network intrusion detection system (NIDS) is influenced by unfair computational distribution among many-core NIDS nodes. To avoid such unfair computational distribution, STEAL is designed to dynamically distribute a large volume of traffic among many-core NIDS nodes based on packet service time, which is represented by the deep packet time in many-core NIDS nodes. From experiments, we show that compared to the commonly used load-balancing algorithm based on arrival rate, STEAL increases the number of received packets (i.e., decreases the number of dropped packets) in many-core NIDS. Specifically, by integrating an open source NIDS (i.e. Bro) with STEAL, we show that even under attack-dominant traffic and with many signatures, STEAL can rapidly improve the performance of many-core NIDS to realize high-speed intrusion detection.

• Journal of Science Education
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• v.44 no.3
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• pp.318-330
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• 2020

This study has been conducted to identify the types and longitudinal changes in the career values of students in science core school. Data collected from 174 students in science core school were analyzed using 11 career value items. First, this study found that there are three types of career value shown in students in science core schools. Second, the career value of students in science core school did not differ by their track. Third, many students of science core high schools have little or no change in their career value values depending on the time of collecting data. However, some students show rapidly changing career values. These findings suggest the need for individualized career education based on the changing trend of students' career values.

• Steel and Composite Structures
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• v.33 no.6
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• pp.837-847
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• 2019

A type of hybrid core made up of thin-walled square carbon fiber reinforced polymer (CFRP) honeycomb and Polymethacrylimide (PMI) foam fillers was proposed and prepared. Numerical model of the core under quasi static compression was established and validated by corresponding experimental results. The compressive properties of the core with different configurations were analyzed through numerical simulations. The effect of the geometrical parameters and foam fillers on the compressive response and energy absorption of the core were analyzed. The results show that the PMI foam fillers can significantly improve the compressive strength and energy absorption capacity of the square CFRP honeycomb. The geometrical parameters have marked effects on the compressive properties of the core. The research can give a reference for the application of PMI foam materials in energy absorbing structures and guide the design and optimization of lightweight and energy efficient cores of sandwiches.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.04a
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• pp.58-58
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• 2005

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.04a
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• pp.46-46
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• 2005

• Journal of Korean Elementary Science Education
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• v.41 no.2
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• pp.325-337
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• 2022

This study aims to determine the implications of the efficient and effective implementation of science core competency (ScC) education by examining the state of science core competencies derived from the 2015 revised elementary school science curriculum and analyzing teachers' and students' perceptions. To this end, this paper investigated the reality of reflecting the science core competencies of science textbooks in a group of third and fourth graders from seven elementary schools who passed the test. In addition, in-depth interviews were conducted with four elementary school teachers who participated in qualification textbook selection, and 156 elementary school students were surveyed to determine their perceptions of science core competencies. Findings showed that, first, 1,586 science core competencies were reflected throughout the textbooks, with an average of 227 per textbook and biology being the most salient area. Second, teachers did not understand the difference between previous inquiry activities in textbooks and ScC education. Third, no statistically significant differences were observed in the perceptions of male and female students on science core competencies, the highest average of perceptions being those of scientific thinking ability. From these results, this study concluded that for ScC education to be realized as a curriculum, textbooks must be organized according to the purpose of core competency education, implementing practical changes, and efforts must be directed toward changing the perceptions of individuals who deliver education.