• Nuclear Engineering and Technology
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• v.44 no.6
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• pp.611-622
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• 2012

"Scaling" plays an important role for safety analyses in the licensing of water cooled nuclear power reactors. Accident analyses, a sub set of safety analyses, is mostly based on nuclear reactor system thermal hydraulics, and therefore based on an adequate experimental data base, and in recent licensing applications, on best estimate computer code calculations. In the field of nuclear reactor technology, only a small set of the needed experiments can be executed at a nuclear power plant; the major part of experiments, either because of economics or because of safety concerns, has to be executed at reduced scale facilities. How to address the scaling issue has been the subject of numerous investigations in the past few decades (a lot of work has been performed in the 80thies and 90thies of the last century), and is still the focus of many scientific studies. The present paper proposes a "roadmap" to scaling. Key elements are the "scaling-pyramid", related "scaling bridges" and a logical path across scaling achievements (which constitute the "scaling puzzle"). The objective is addressing the scaling issue when demonstrating the applicability of the system codes, the "key-to-scaling", in the licensing process of a nuclear power plant. The proposed "road map to scaling" aims at solving the "scaling puzzle", by introducing a unified approach to the problem.

• Journal of The Korean Association For Science Education
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• v.17 no.1
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• pp.11-19
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• 1997

Students' protocols obtained from think-aloud interviews were analyzed in the aspects of the success at first two problem-solving stages (understanding and planning), the time to complete a problem, the time at each problem-solving stage, the number of transition, and the transition rate. These were compared in the aspects of the context of problem, the success in solving problem, students' logical reasoning ability, spatial ability, and learning approach. The results were as follows:1. Students tended to spend more time in everyday contexts than in scientific contexts, especially at the stages of understanding and reviewing. The transition rate during solving a problem in everyday contexts was greater than that in scientific contexts. 2. Unsuccessful students spent more time at the stage of understanding, but successful students spent more time at the stage of planning. 3. Students' logical reasoning ability, as measured with the Group Assessment of Logical Thinking, was significantly correlated with the success in solving problem. Concrete-operational students spent more time in completing a problem, especially understanding the problem. 4. Students' spatial ability, as measured with the Purdue Visualization of Rotations Test and the Find A Shape Puzzle, was significantly correlated with their abilities to understand a problem and to plan for its solution. 5. Students' learning approach, as measured with the Questionnaire on Approaches to Learning and Studying, was not significantly correlated with the success in solving problem. However, the students in deep approach had more transitions and greater transition rates than the students in surface approach.

• Journal of Creative Information Culture
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• v.5 no.3
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• pp.295-306
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• 2019

Despite the popularity and convenient accessibility of puzzles, the variety of puzzles have led to a lack of research on the nature of the puzzle itself. In guiding certain skills, such as abstractness, creativity, and logic, a teacher should have the thinking skill and strategy that appear in solving puzzles. In this study, the mathematical thinking that appears in solving puzzles from the perspective of experts is identified, and the strategies and characteristics are described and classified accordingly. For this purpose, we analyzed 85 math puzzles including the well-know puzzles to the public, plus puzzles from a popular book for the gifted student. The research analysis shows that there are 6 types of mathematics puzzles in which require mathematical thinking.

• School Mathematics
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• v.4 no.3
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• pp.483-494
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• 2002

A Situation-problem, one of the problems in school mathematics, plays a role as the starting point of teaming mathematics. It leads to construct knowledge which is a tool for solving the problems. Whether the problem is a situation-problem or not, it depends upon how to use that problem. Since posing situation-problems is accompanied by prior analysis and planning for teaching in the class, it is a difficult task. This paper focuses on the characteristics of situation-problems and on how their characteristics are realized in the process of classroom instruction. For this purpose, it analyzes the context of classroom instruction to which the 'puzzle problem' model suggested by Brousseau is applied. The model is considered as a typical situation-problem, which aims at proportionality and linearity. In addition, this paper suggests various sources of information that are useful in posing the situation-problems related to the ratio concepts.

• Journal for History of Mathematics
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• v.20 no.3
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• pp.43-58
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• 2007

We review the eastern frog jump game and the western solitaire to apply the Baduk Pieces Game to mathematical education. This study introduce a didactical method of Baduk Pieces Game which is constructed with simplification, generalization, and extension. This didactical applications of the Baduk Pieces Game gives the students opportunities of patterns, generalization, and problem solving strategies.

• BMB Reports
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• v.49 no.5
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• pp.249-254
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• 2016

All living things share some common life processes, such as growth and reproduction, and have the ability to respond to their environment. However, each type of organism has its own specialized way of managing biological events. Genetic sequences determine phenotypic and physiological traits. Based on genetic information, comparative genomics has been used to delineate the differences and similarities between various genomes, and significant progress has been made in understanding regenerative biology by comparing the genomes of a variety of lower animal models of regeneration, such as planaria, zebra fish, and newts. However, the genome of lizards has been relatively ignored until recently, even though lizards have been studied as an excellent amniote model of tissue regeneration. Very recently, whole genome sequences of lizards have been uncovered, and several attempts have been made to find regeneration factors based on genetic information. In this article, recent advances in comparative analysis of the lizard genome are introduced, and their biological implications and putative applications for regenerative medicine and stem cell biology are discussed.

• Journal of the Korea Society of Computer and Information
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• v.18 no.4
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• pp.183-190
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• 2013

Many researchers in the 21st century has found that robot education is effective to develop the learners' creativity and problem-solving ability. However, the robot education can only be applied to the students whose computer skills are high. Also it can be taught in the well-prepared computer classroom. Students have to learn machine language to control their robots, and robots are controlled by different types of software. Therefore this study has constructed command-based programming blocks to do a robot programming without computers. It also presents a prototype of the programming process and a technological method to combine the command and the programming blocks. We used the blocks which are similar with something in flow chart: to support intuition, and to help students transfer what they learned. And types of blocks and details are described for the Robot Programing Education. Combination of command blocks is made by RS-485 connection method and, it is designed to intercommunicate with connected blocks. It also presents a prototypes: of the programming process using designed command blocks, and of the possibility of Unplugged Robot Education System.

• Journal for History of Mathematics
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• v.20 no.1
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• pp.57-72
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• 2007

Recently, dissection puzzles such as pentominoes have been used in mathematics education. But they are not actively applicable as a tool of problem solving or introducing mathematical concepts since researches about the historical background and developments of mathematical applications of such puzzles have not been effectively accomplished. In this article, in order to use pentominoes in mathematical teaming effectively, we first investigate geometric problems related to dissection puzzles and the historic background of development of pentominoes. And then we collect and classify data related to pentomino activities which can be applicable to mathematics classes based on the 7th elementary school national curriculum. Finally, we suggest several basic materials and directions to develop more systematic learning materials about pentominoes.

• Journal of Elementary Mathematics Education in Korea
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• v.14 no.3
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• pp.567-581
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• 2010

The basic direction of mathematical education for a 21st century is focused on helping student to understand mathematics and develop their problem solving abilities, mathematical dispositions and mathematical thinking. Elementary mathematics teachers should help students make sense of mathematics, confident of their ability, and make learning environment comfortable for students to participate in. The best way is to provide chances to play a game for students, considering educational value of game and new directions for mathematical education. Therefore I would like to develop an mathematical game to conform mathematical ideas, and apply it, as well as strengthen students' mathematical disposition such as confidence, flexibility, interest and curiosity to improve quality of mathematical education. If students are helped to be interested in mathematics through mathematical games, they regard mathematics as interesting and challengeable subject to let themselves think many ways.

• The KIPS Transactions:PartD
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• v.15D no.6
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• pp.777-784
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• 2008

Recently in the field of model checking, to overcome the state explosion problem, the method of using a SAT-solver is mainly researched. To use a SAT-solver, the system to be verified is translated into CNF and the Boolean cardinality constraint is widely used in translating the system into CNF. In BCC it is dealt with set of boolean variables, but there is no translating method of the sequence among Boolean variables. In this paper, we propose methods for translating the problem, which is extracting a subsequence with length k from a sequence of Boolean variables, into CNF formulas. Through experimental results, we show that our method is more efficient than using only BCC.