• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.6
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• pp.581-584
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• 2000

In order to obtain the fundamental data about method of luring fish schools by underwater audible sound, the auditory threshold of black rockfish Sebastes inermis on the coast of Cheju Island was investigated by heartbeat conditioning technique using pure tones coupled with a delayed electric shock, The audible range of black rockfish extended from 80 Hz to 800 Hz with a peak sensitivity at 300 Hz. The mean auditory thresholds of black rockfish at the frequencies of 80 Hz, 100 Hz, 200 Hz, 300 Hz, 500 Hz and 800 Hz were 102 dB, 103 dB, 99 dB, 96 dB, 116 dB and 122 dB, respectively, As the frequency became higher than 300 Hz, the auditory threshold increased rapidly.

• Journal of Engineering Education Research
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• v.11 no.1
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• pp.5-14
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• 2008

The purpose of this study is to analyze how a well-structured cognitive reflection journal can affect a learner's metacognition and learning achievement in the area of Engineering Education. The objects of this study were 143 students in total (experimental group: 52, control group: 91) who are taking the 'Fundamental Semiconductor Engineering' course in the Engineering Department at D college in the metropolitan area. For his particular study, we undertook three steps as follows. First, we verified that the two groups of students were equal in areas of metacognition and learning achievement. Second, the experimental group was asked to keep writing the well-structured reflection journal for four weeks and the control group was not. Third, we evaluated the metacognition and learning achievement. This study used a questionnaire to measure metacognition by Sperling(2002) in a Korean translation as well as a well-structured cognitive reflection journal. As a result, we found that the well-structured cognitive reflection journal affects learners positively in the sense of metacognition ability, continuity as well as learning achievement.

• Journal of Technology Innovation
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• v.20 no.1
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• pp.75-114
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• 2012

Transition from imitation based catch-up to new value creation based post catch-up innovation system is becoming the main issue for Korea. The notion of post catch-up research highlights the understanding of new patterns of innovation and the interrelationship among innovating agents within systems of innovation. More specifically, it is a context specific framework which accommodates discontinuum of technological innovation from the past and a creation of new organizational arrangement and institutions. Moreover, post catch-up approach follows the tradition of development, institutional and evolutionary theories context. This paper, therefore, explores whose focus is on the possibility of new theoretical development and new research agenda.

• Journal of the Korean School Mathematics Society
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• v.12 no.2
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• pp.151-170
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• 2009

The purpose of the study is to analyze the sixth graders' understanding of concepts and operation about fraction. The test was administered and analyzed to 707 sixth graders' performance on fractions after the fraction instructions in elementary schools in Seoul, Korea. The participants are asked to answer two sets of questions for 40 minutes. First, they are asked to answer to 16 problems about the concepts of fraction with respect to part-whole, ratio, operator, measure, quotient, equivalent, and operations. Second, specially, to investigate sixth graders' ability of drawing and describing the situation of division including fraction, the descriptive problem asked students (1) to describe $3\;{\div}\;\frac{1}{2}$ into pictorial representation and (2) to write the solving process. The participants of this study didn't show deep understandings about the concepts and operation of fraction. The degree of understanding of subconstructs of fraction shows that their knowledge of ratio concept with respect to fraction was highest while their understanding of measure with respect to fraction was lowest. Considering their wrong answers, about 59% of participants showed misconception to the question of naming one fraction that appears between $\frac{1}{5}$ and $\frac{1}{6}$. Further, they didn't explain their understanding with drawing about the division of fraction ($3\;{\div}\;\frac{1}{2}$).

• Journal of Elementary Mathematics Education in Korea
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• v.9 no.2
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• pp.161-180
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• 2005

The purpose of this study is to delve into how elementary mathematics textbooks deal with the areas of triangles and quadrilaterals from a viewpoint of the Didactic Transposition Theory. The following conclusion was derived about the teaching of the area concept: The area concept started to be taught perfectly in the 7th curricular textbook, and the focus of area teaching was placed on the area concept, since learners were gradually given opportunities to compare and measure areas. As to the area formulae of triangles and quadrilaterals, the following conclusions were made: First, the 1st curricular, the 2nd curricular and the 3rd curricular textbooks placed emphasis on transposition by textbooks, and the 4th curricular, the 5th curricular and the 6th curricular textbooks accentuated transposition by teachers. The 7th curricular textbooks put stress on knowledge construction by learners; Second, the focus of teaching shifted from a measurement of area to inducing learners to make area formula. Namely, the utilization of area formula itself was accentuated, while algorithm was emphasized in the past; Third, the way to encourage learners to produce area formula changed according to the curricula and in light of learners' level, but a wide range of teaching devices related to the area formulae were removed, which resulted in offering less learning chances to students; Fourth, what to teach about the areas of triangles and quadrilaterals was gradually polished up, and the 7th curricular textbooks removed one of the overlapped area formula of triangle.

• Journal of Digital Convergence
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• v.16 no.1
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• pp.317-325
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• 2018

A satisfactory ending of the project is crucial for the students to achieve success experience. In this study, we analyze the teams' dismantling before the project deadline. We propose a team dissolution model based on the assumption that the disharmony caused by the members' personality traits is the main reason for the team break up. The Dark Triad and the Communion are introduced to build the model. We simulated the proposed model using an agent-based simulation and analyzed the results. We found that the ratio of owning DT impacts the maximum allowable size of the team and the team's rate of dissolution, but the team has been able to reduce the team's dissolution rate by increasing the team's harmony. We expect that we efficiently used the developed model with the agent-based simulation for the studies related to the dismantling of teams.

• Journal of The Korean Association of Information Education
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• v.4 no.1
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• pp.83-97
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• 2000

The utilization of Information and Communication Technology(ICT) has become increasingly important in educational endeavors. The purpose of this paper is to analyze the current status of the utilization of ICT in elementary schools and to investigate problems and tasks to be solved for the effective use of ICT. Concerning the first purpose, a survey was conducted in February 2000, and the results are reported in this paper. For the second purpose, hindering factors are analyzed in relation to hardware, software, teacher training, curriculum, and administrative and financial support. Undoubtedly, ICT has been playing an important role in education. The effectiveness of this role largely depends upon how ICT is utilized in educational setting. Thus educators should carefully consider all aspects of the implementation of ICT, and devote efforts to solve problems occurring in the process of the implementation.

• Communications of Mathematical Education
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• v.24 no.3
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• pp.611-626
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• 2010

The purpose of this study is to explore the composite properties of linear functions using CAS calculators. The meaning and processes in which technological tools such as CAS calculators generated to instrument are reviewed. Other theoretical topic is the design of an exploring model of observing-conjecturing-reasoning and proving using CAS on experimental mathematics. Based on these background, the researchers analyzed the properties of the family of composite functions of linear functions. From analysis, instrumental capacity of CAS such as graphing, table generation and symbolic manipulation is a meaningful tool for this exploration. The result of this study identified that CAS as a mediator of mathematical activity takes part of major role of changing new ways of teaching and learning school mathematics.

• Journal of Elementary Mathematics Education in Korea
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• v.18 no.3
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• pp.399-424
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• 2014

Although teacher preparation programs are important for prospective teachers to build a foundation of teaching expertise, there has been lack of research in this area. This paper analyzed in what ways prospective teachers' ability in describing and commenting on elementary mathematics instruction has been changed while they were taking in the course of teaching elementary school mathematics. The results of this study showed that in late description the teachers tended to notice the core flow of a lesson and the use of instructional strategies appropriate to the mathematical content to be taught. They also tended to comment on instructional strategies and mathematical discourse from the teacher's perspective and evaluated them without alternative approaches. A noticeable change occurred in late comments wherein prospective teachers considered both the teacher and students, supported their comments by theories they had learned through the course, and interpreted the classroom events they had noticed. Building on these results, this paper closes with implications of teacher education programs to enhance prospective teachers' ability to analyze elementary mathematics lessons.

• Journal of Fisheries and Marine Sciences Education
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• v.12 no.1
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• pp.1-10
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• 2000

In order to obtain the fundamental data on the auditory thresholds of fishes for marine ranching, the auditory thresholds of black rock fish Sebastes Schlegeli were measured in the presence of masking noise in the spectrum level range of 73 - 83dB (0dB re $1{\mu}Pa/{\sqrt{Hz}}$) with a classical cardiac conditioning technique. Critical ratios were about 19 - 30dB at 80 - 300Hz and 46 - 54dB at 500 - 800Hz. The ratio increased almost linearly with increasing frequency to 500Hz. The noise spectrum level at the start of masking was about 70dB within the frequency range of 80 - 800Hz excepting 65dB at 300Hz. This suggests that hearing of the black rock fish is masked in the natural environment with the noise spectrum level above 65dB. The sound pressure level of which the signal sound of 100 - 200Hz is recognized by black rock fish under the ambient noise is above 90dB and the critical ratio of them is above 20dB.