• Journal of Gifted/Talented Education
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• v.15 no.1
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• pp.85-102
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• 2005

Some properties on the mathematical hyper-dimensional figures by 'the principle of the permanence of equivalent forms' was investigated. It was supposed that there are 2 conjectures on the making n-dimensional figures : simplex (a pyramid type) and a hypercube(prism type). The figures which were made by the 2 conjectures all satisfied the sufficient condition to show the general Euler's Theorem(the Euler's Characteristics). Especially, the patterns on the numbers of the components of the simplex and hypercube are fitted to Binomial Theorem and Pascal's Triangle. It was also found that the prism type is a good shape to expand the Hasse's Diagram. 5 mathematically gifted high school students were mentored on the investigation of the hyper-dimensional figure by 'the principle of the permanence of equivalent forms'. Research products and ideas students have produced are shown and the 'guided re-invention method' used for mentoring are explained.

• The Mathematical Education
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• v.50 no.2
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• pp.213-231
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• 2011

The purpose of this study is to analyze the 6th graders' understanding of the concepts of variable on various aspects of school algebra. For this purpose, the test of concepts of variable targeting a sixth-grade class was conducted and then two students were selected for in-depth interview. The level of mathematics achievement of the two students was not significantly different but there were differences between them in terms of understanding about the concepts of variable. The results obtained in this study are as follows: First, the students had little basic understanding of the variables and they had many cognitive difficulties with respect to the variables. Second, the students were familiar with only the symbol '${\Box}$' not the other letters nor symbols. Third, students comprehended the variable as generalizers imperfectly. Fourth, the students' skill of operations between letters was below expectations and there was the student who omitted the mathematical sign in letter expressions including the mathematical sign such as x+3. Fifth, the students lacked the ability to reason the patterns inductively and symbolize them using variables. Sixth, in connection with the variables in functional relationships, the students were more familiar with the potential and discrete variation than practical and continuous variation. On the basis of the results, this study gives several implications related to the early algebra education, especially the teaching methods of variables.

• The Mathematical Education
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• v.51 no.4
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• pp.351-375
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• 2012

This research is a case study of the changes of students's problem solving ability and affective characteristics when we apply to general students MG-CPS model which is creative problem solving model for gifted students. MG-CPS model which was developed by Kim and Lee(2008) is a problem solving model with 7-steps. For this study, we selected 7 first grade students from girl's high school in Seoul. They consisted of three high level students, two middle level students, and two low level students and then we applied MG-CPS model to these 7 students for 5 weeks. From the study results, we found that most students's describing ability in problem understanding and problem solving process were improved. Also we observed that high level students had improvements in overall problem solving ability, middle level students in problem understanding ability and guideline planning ability, and that low level students had improvements in the problem understanding ability. In affective characteristics, there were no significant changes in high and middle level classes but in low level class students showed some progress in all 6 factors of affective characteristics. In particular, we knew that the cause of such positive changes comes from the effects of information collection step and presenting step of MG-CPS model.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.23 no.4
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• pp.204-217
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• 2018

This study proposes a cost-effective method to monitor coastal environments using e-Navigation-implemented domestic and international ferries, and to analyze big data of records such as wind, temperature, salinity, waves, and currents that are gathered through e-Navigation system. First, we present the concept and architecture of e-Navigation operation system based on the General Information Center on Maritime Safety and Security. Then, the marine observation system that can be applied to ferries operating in our nation's territory is discussed. Analytical methods, such as spatio-temporal mixed effects model, ensemble method, and meshfree method, in handling real-time big data obtained by the e-Navigation observing system are then explained in detail. This study will support the implementation of the Korean e-Navigation project that focuses on the safety of small vessels such as coasters and fishing vessels.

• Journal of the Korean Society for information Management
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• v.36 no.1
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• pp.169-190
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• 2019

This study aims to identify the effects of teachers' recognition and application of 2015 revised national curriculum on their educational information needs in high schools. Several in-depth interviews and a questionnaire survey with the teachers, who were in charge of teaching common courses, such as Korean language, mathematics, English, social studies, and science, in general public high schools in Incheon, were executed for the purpose. As a result, the teachers' recognition and application affected their educational information needs in part. Especially, new demands on small sized copies and learning information sources were identified which were related to the application of 2015 revised national curriculum. Based on the results, we proposed several improvements of school library operations, such as small sized local consortium for sharing resources and providing referral services, in order to strengthen the gateway role of school libraries.

• Journal of Practical Engineering Education
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• v.12 no.2
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• pp.363-369
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• 2020

This study intends to examine effects of python education for adolescents. 6 primary studies were chosen through careful search process and investigated through meta-analysis. Research findings were as follows. The total effect size was 0.684. Second, the effect sizes of dependent variables were academic achievement 0.871, cognitive domain 0.625, and affective domain 0.428 in order. Third, for cognitive domain, the effect sizes were self-efficacy 0.833, problem-solving 0.283, computing thinking 0.276, and coding competency 0.251 in order. Fourth, for affective domain, the effect sizes were learning interest 0.560 and programming interest 0.417 in order. Fifth, regarding school level, the effect sizes were middle school 0.851, high school 0.585, and college 0.435 in order. Finally, for subject areas, the effect sizes were mathematics 1.057, design 0.595, information 0.585, and software 0.28 in order.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.4
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• pp.17-24
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• 2010

A differential fault attack(DFA) is one of the most efficient side channel attacks on block ciphers. Almost all block ciphers, such as DES, AES, ARIA, SEED and so on., have been analysed by this attack. In the case of the known DFAs on SEED, the attacker induces permanent faults on a whole left register of round 16. In this paper, we analyse SEED against DFA with differential characteristics and addition-XOR characteristics of the round function of SEED. The fault assumption of our attack is that the attacker induces 1-bit faults on a particular register. By using our attack, we can recover last round keys and the master key with about $2^{32}$ simple arithmetic operations. It can be simulated on general PC within about a couple of second.

• International Journal of Computer Science & Network Security
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• v.22 no.10
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• pp.291-297
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• 2022

Modern challenges in the educational environment force scientists and practitioners to search for an adequate answer. In particular, the war in Ukraine demonstrated the importance of developing information competence as one of the main means of distinguishing true information from a whole stream of fake news. This is especially relevant in connection with the introduction of distance learning when students must find and process a large amount of information on their own. Therefore, the purpose of the article is to analyze the training of higher education students through the prism of acquiring the necessary level of informational competence in war conditions. For this, general scientific and special research methods, as well as the experimental method, were used. In the results, the peculiarities of the interpretation of information competence in the distance form of education among modern researchers are determined, the psychological components of resistance to fakes are analyzed. Based on the conducted empirical measurements, it was established that thorough work on student education gives positive skills when working independently with Internet materials, strengthens the ability to distinguish false information and propaganda from the real state of affairs. The conclusions summarize the results of the empirical research and suggest ways to improve the situation with the formation of information competence.

• International Journal of Computer Science & Network Security
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• v.23 no.1
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• pp.64-70
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• 2023

Maritime transport is dominant in the overall volume of all international transportation. Existence and overcoming of problems, which cause pressure on shipping safety, remain actual and fully concern both maritime and inland transport. Increasing speed and cargo capacity of the ships along with the reduction of crew members lead to the automation of a growing number of work processes, which indicates the need to actively introduce appropriate measures in the security system of sea-going ships and commercial ports and to develop modern approaches to minimize negative events and incidents in the process of ship operation. Advantages in use of modern methods of monitoring the safety of ship operations, management of possible events and incidents, including investigation of accidents, first, aimed at prevention of negative occurrences and ways of prevention on this basis. Considering statistics on incidents increase, this work presents analysis of general ship accident rate, study of major accidental events growth annually, and investigation of causes of incidents, which most frequently occur in port waters and at open sea. A survey of current approaches to ensuring the safety of shipping by implementing effective tools, such as event and incident management, has been conducted.

• Monthly Notices of the Royal Astronomical Society
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• v.491 no.2
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• pp.2268-2279
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• 2020

It is known observationally that the major axes of galaxy clusters and their brightest cluster galaxies are roughly aligned with each other. To understand the origin of the alignment, we identify 40 cluster-sized dark matter (DM) haloes with masses higher than 5 × 10¹³ M_⊙ and their central galaxies (CGs) at z ≈ 0 in the Horizon-AGN cosmological hydrodynamical simulation. We trace the progenitors at 50 different epochs between 0 < z < 5. We then fit their shapes and orientations with a triaxial ellipsoid model. While the orientations of both DM haloes and CGs change significantly due to repeated mergers and mass accretions, their relative orientations are well aligned at each epoch even at high redshifts, z > 1. The alignment becomes tighter with cosmic time; the major axes of the CGs and their host DM haloes at present are aligned on average within ~30° in the 3D space and ~20° in the projected plane. The orientations of the major axes of DM haloes on average follow one of the eigenvectors of the surrounding tidal field that corresponds to the slowest collapsing (or even stretching) mode, and the alignment with the tidal field also becomes tighter. This implies that the orientations of CGs and DM haloes at the present epoch are largely imprinted in the primordial density field of the universe, whereas strong dynamical interactions such as mergers are important to explain their mutual alignment at each epoch.