• The Mathematical Education
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• v.46 no.4
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• pp.357-369
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• 2007

Teachers and students' knowledge of zero was investigated through data collected from 16 preservice secondary mathematics teachers and 20 gifted secondary school students. Results showed that these teachers and students had an inadequate knowledge about zero. They exhibited a reluctance to accept zero as an attribute for classification, confusion as to whether or not zero is a number, and stable patterns of computational error. Although leachers and researchers have long recognized the value of analyzing student errors for diagnosis and remediation, students have not been encouraged to take advantage of errors as learning opportunities in mathematics instruction. The article suggests using errors as springboards for inquiry in action, discusses its potential contributions to mathematics instruction by analyzing students and preservice teachers errors related to zero.

• The Mathematical Education
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• v.46 no.4
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• pp.423-443
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• 2007

Based on the framework of Huffered-Ackles, Fuson and Sherin(2004), data were analyzed in terms of 3 components: explaining(E), questioning(Q) and justifying(J) of students' mathematical concepts and problem solving in a math classroom. The students used varied presentations to explain and justify their mathematical concepts and ideas. They corrected their mathematical errors or misconceptions through discourses. In addition, they constructed and clarified their concepts and thinking while they were interacted. We were able to recognize there was a special feature in discourses that encouraged the students to construct and develop their mathematical concepts. As they participated in math class and received feedback on their learning, the whole class worked cooperatively in a positive way. Their discourse was improved from the level of the actual development to the level of the potential development and the pattern of interaction moved from ERE(Elicitaion-Response-Elaboration to PD(Proposition Discussion).

• Journal of Fisheries and Marine Sciences Education
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• v.10 no.1
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• pp.79-86
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• 1998

In this study, the adhesive effect, blistering behavior and electrochemical polarization behavior of red lead film by the pretreatment work of sandblasting and potassium chromate($K_2CrO_4$) were investigated to prevent the corrosion of gas storage tank under marine environment. The main results obtained are as follows : 1) The adhesive effect of red lead film by the pretreatment work of sandblasting and potassium chromate is more improved than that of red lead film. 2) The blistering occurrence of red lead film by the pretreatment work of sandblasting and potassium chromate is more delayed than that of red lead film. 3) As the anodic potential is increased, corrosion current density of red lead film by the pre treatment work of sandblasting and potassium chromate is lower drained than that of red lead film.

• Journal of Fisheries and Marine Sciences Education
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• v.23 no.4
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• pp.626-641
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• 2011

The aims of this study are to provide future prospects of the Korean ornamental fish industry and to seek for its development direction based on analysis of its problems and its domestic and foreign situations and circumstances. The ornamental fish market has continuously grown due to increase of domestic and international demand. In this respect, the Korean ornamental fish industry has also high potential. However, the industry still has several problems such as artisanal industrial structure, a lack of investment related with R&D, poor information on the domestic and international ornamental fish industry, underdeveloped regulations and policies, low public awareness and less effort to expand the market, and a lack of regulatory and policy support. Therefore, overcoming these problems above, the Korean government has to carry out following things : establishment of institutional and industrial foundation, intensive R&D investment, exploitation of domestic and foreign markets, and systematic information gathering for ornamental fish industry.

• International journal of advanced smart convergence
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• v.10 no.4
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• pp.198-205
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• 2021

With the development of blockchain technology, the scope of blockchain applications has expanded rapidly. Blockchain decentralization allows transaction participants to make transparent and safe transactions without a third trust agency. A distributed ledger-based system enables transparent and trusted business for anonymous users. For this reason, many companies apply blockchain to various fields such as logistics, electronic voting, and real estate. Despite this interest, there are still not enough case studies confirming the potential of blockchain as a concrete business model. Therefore, it is necessary to study how blockchain technology can change the existing business model and connect it to a new business model. In this paper, we propose blockchain-based business models and workflow types in various fields such as healthcare, logistics, and energy. We also present application cases. We expect to help companies apply blockchain to their business.

• Journal of the Korean Institute of Educational Facilities
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• v.26 no.1
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• pp.3-8
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• 2019

Most of the unused facility in urban areas is perceived as an unreasonable space that damages cityscapes. However, unused space has the advantage of having historical value and potential for new development. In consideration of this, various plans have recently been made in terms of cultural use of unused space. The core is the performing arts culture space where various expressions can be expressed. Changes in the educational space that meet the various conditions required in future societies are also one of the topics to be discussed. In this study, we analyze the performance facilities utilizing the unused space and study the direction of educational facilities based on performance.

• Research in Mathematical Education
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• v.21 no.1
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• pp.15-34
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• 2018

This paper describes how communicative technology between two classrooms located in different sociocultural contexts was used to support mathematics instruction. I analyzed what interactions emerged using the communicative technology, how sociocultural differences were leveraged to construct mathematical knowledge, and how students built this knowledge together across urban and rural classrooms. The results show that reciprocal interactions emerged. Teachers co-designed lesson plans and tasks with consideration of the different classroom social contexts. Based on those teachers' interactions, students had opportunities to justify their ideas and to prepare answers before the connected discussions, and a wide spectrum of ideas was synthesized as collaborative knowledge. These findings suggest that communicative technology has the potential to enhance learning opportunities for students across different social contexts.

• Research in Mathematical Education
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• v.24 no.3
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• pp.255-278
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• 2021

Proof serves a critical role in mathematical practices as well as in fostering student's mathematical understanding. However, the research literature accumulates results that there are not many opportunities available for students to engage with proving-related activities and that students' understanding about proof is not promising. This unpromising state of instruction of proof calls for a novel approach to address the aforementioned issues. This study investigated an instruction of proof to explore a pedagogy to teach how to prove. The teacher utilized the way of problem posing to make proving a routine part of everyday lesson and changed the classroom culture to support student proving. The study identified the teacher's support for student proving, the key pedagogical changes that embraced proving as part of everyday lesson, and what changes the teacher made to cultivate the classroom culture to be better suited for establishing a supportive community for student proving. The results indicate that problem posing has a potential to embrace proof into everyday lesson.

• Advances in nano research
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• v.13 no.3
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• pp.247-257
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• 2022

Extraordinary properties of nanocomposites make them a primary replacement for many conventional materials. Anterior cruciate ligament (ACL) reconstruction, which is a frequent surgery in sport activities, is one of the fields in which nanocomposites could be utilized. In the present study, the mechanical properties of different porous scaffolds made from graphene nano-composites are presented ad load bearing capacity of these materials is calculated using finite element method. The numerical results are further compared with experimental published data. In addition, several geometrical and material parameters are analyzed to find the best configuration of nanocomposite scaffolds in reconstruction of ACL. Moreover, coating of detoxification chemicals are extremely easier on the nano-structured materials than conventional one. Detoxification potential of nano-composites in the injured body are also discussed in detail. The results indicated that nano-composite could be successfully used in place of auto- and allografts and also instead of conventional metallic screws in reconstruction of ACL.

• Journal of Environmental Science International
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• v.31 no.10
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• pp.891-899
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• 2022

This study investigated whether an educational program could alter students' perceptions of the causes of and solutions to climate change. On October 23, 2020, a 3-hour climate change educational program was provided to 400 high school students in Suncheon City, (Jeonnam Province, South Korea). According to the program, climate change represents a social dilemma, or tragedy of the commons; it also asserts that collective action aimed at strengthening government policy is the optimal solution to climate change, and concludes that motivated citizens should convey their opinions directly to the government through political action. After the program, the students made and shared placards calling for policy-based responses to climate change. Questionnaires completed by the students before and after the program revealed that their perceptions of the causes of and solutions to climate change changed significantly. This case study indicates that education programs have the potential to alter students' perspectives and promote actions aimed at mitigating and adapting to climate change.