• Journal of Plant Biotechnology
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• v.48 no.4
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• pp.289-303
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• 2021

Covid-19 is an ongoing pandemic as we speak in 2022. This infectious disease is caused by the SARS-CoV-2 virus, which infects cells by binding to the angiotensin-converting enzyme 2 (ACE2) receptor on the cell surface. Thus, strategies that inhibit the binding of SARS-CoV-2 to the ACE2 receptor can stop this contagion. Hanjeli (Coix lacryma-jobi) essential oil contains many bioactive compounds, including dodecanoic acid; tetradecanoic acid; 7-Amino-8-imino-2-(2-imino-2H-chromen-3-yl); and 1,5,7,10-tetraaza-phen-9-one. These compounds suppress viral replication and may prevent Covid-19. Accordingly, this study assessed whether, these four limonoid compounds can block the ACE2 receptor. To this end, their physicochemical properties were predicted using Lipinski's "rule of five" on the SwissADME website, and their toxicity was assessed using the online tools ProTox and pkCSM. Additionally, their interactions with the ACE2 receptor were predicted via molecular docking using Autodock Vina. All the four compounds satisfied the "rule of five" and tetradecanoic acid was predicted to have a higher affinity than the comparison compound remdesivir and the original ligand of ACE2. Molecular docking results suggested that the compounds from hanjeli essential oil interact with the active site of the ACE2 receptor similarly as the original ligand and remdesivir. In conclusion, hanjeli essential oil contains compounds predicted hinder the interaction of SARS-CoV-2 with the ACE2 receptor. Accordingly, our data may facilitate the development of a phytomedical strategy against SARS-CoV-2 infection.

• East Asian mathematical journal
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• v.25 no.3
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• pp.321-341
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• 2009

The purpose of this study was to examine the effect of the manipulative materials in the Australian Maths 300 program by applying it to Korean Elementary Mathematics Education - based on parts of 'Probability and Statistics', and 'Symbol and Expression'. In order to this purpose, we select appropriate Maths 300's manipulate materials that could be used to obtain learning objectives within class time for each part, four lessons with the materials were taught at to third, fourth, and fifth grade students of elementary School. The effect of the teaching was analyzed by videotape and student opinion. The results of this study are the following: First, the manipulative tools were almost entirely lacking for the 'Probability and Statistics' section without a 'number of cases' unit. The tools presented in the 'Symbol and Expression' section were helpful in the games that were used for checking preceding learning. Second, the results of using the Math 300 manipulative materials in class showed that the students were eager to be involved in the activities using those materials and to find their own solutions in problem-solving questions that were suited to them; these led to them making their own questions. In response to questioning about the use of the manipulative materials, the students stated that it was easy and fun for them to use the manipulative materials, to solve the problems for themselves, and that they would like to continue practicing the activities in the future. Finally, Studies on the presentation of a variety of manipulative materials including those in this study that can used in problem-solving learning and other learning fields, and the methodology for the use of manipulative materials can be enhanced through further studies.

• Journal of The Korean Association For Science Education
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• v.26 no.3
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• pp.307-316
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• 2006

The purpose of this study was to analyze intellectual characteristics of elementary students in science-gifted education. For this, 72 science-gifted students were selected. Multiple intelligences, creativity, and the science process skills of these students were tested. To compare these traits with those of general students, 78 general students were also tested. The results of this study indicated that science-gifted students significantly surpassed general students in the areas of logical-mathematics, intra-person, and naturalist. Especially, the intelligences of logical-mathematics and intra-person were strong point of the science-gifted students. But music intelligence among the 8 intelligence was weak point. Creativity and the science process skills of the students in science-gifted education excelled those of general students. Therefore, to enhance the efficiency of the science-gifted education program in elementary school, it is necessary to consider the intellectual characteristics of the students.

• Journal of Korea Water Resources Association
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• v.44 no.7
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• pp.511-522
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• 2011

Two-dimensional shallow water model based on the cut cell and the adaptive mesh refinement techniques is presented in this paper. These two mesh generation methods are combined to facilitate modeling of complex geometries. By using dynamically adaptive mesh, the model can achieve high resolution efficiently at the interface where flow changes rapidly. The HLLC Reimann solver and the MUSCL method are employed to calculate advection fluxes with numerical stability and precision. The model was applied to simulate the extreme urban flooding experiments performed by the IMPACT (Investigation of Extreme Flood Processes and Uncertainty) project. Simulation results were in good agreement with observed data, and transient flows as well as the impact of building structures on flood waves were calculated with accuracy. The cut cell method eased the model sensitivity to refinement. It can be concluded that the model is applicable to the urban flood simulation in case the effects of sewer and stormwater drainage system on flooding are relatively small like the dam brake.

• Journal of Communications and Networks
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• v.12 no.4
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• pp.289-307
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• 2010

The problem of model selection arises in a number of contexts, such as subset selection in linear regression, estimation of structures in graphical models, and signal denoising. This paper studies non-asymptotic model selection for the general case of arbitrary (random or deterministic) design matrices and arbitrary nonzero entries of the signal. In this regard, it generalizes the notion of incoherence in the existing literature on model selection and introduces two fundamental measures of coherence-termed as the worst-case coherence and the average coherence-among the columns of a design matrix. It utilizes these two measures of coherence to provide an in-depth analysis of a simple, model-order agnostic one-step thresholding (OST) algorithm for model selection and proves that OST is feasible for exact as well as partial model selection as long as the design matrix obeys an easily verifiable property, which is termed as the coherence property. One of the key insights offered by the ensuing analysis in this regard is that OST can successfully carry out model selection even when methods based on convex optimization such as the lasso fail due to the rank deficiency of the submatrices of the design matrix. In addition, the paper establishes that if the design matrix has reasonably small worst-case and average coherence then OST performs near-optimally when either (i) the energy of any nonzero entry of the signal is close to the average signal energy per nonzero entry or (ii) the signal-to-noise ratio in the measurement system is not too high. Finally, two other key contributions of the paper are that (i) it provides bounds on the average coherence of Gaussian matrices and Gabor frames, and (ii) it extends the results on model selection using OST to low-complexity, model-order agnostic recovery of sparse signals with arbitrary nonzero entries. In particular, this part of the analysis in the paper implies that an Alltop Gabor frame together with OST can successfully carry out model selection and recovery of sparse signals irrespective of the phases of the nonzero entries even if the number of nonzero entries scales almost linearly with the number of rows of the Alltop Gabor frame.

• Journal of the Korean School Mathematics Society
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• v.17 no.3
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• pp.359-384
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• 2014

The purpose of this study is inquire the reaction and adaptability of the mathematically gifted student, in the case of introduce learning materials based on GeoGebra in real class. The study program using GeoGebra consist of 'construction of fundamental figures', 'making animation with using slider tools' (graph of a function, trace of a figure, definite integral, fixed point, and draw a parametric curve), make up the group report after class. In detail, 1st to 15th classes are mainly problem-solving, and topic-exploring classes. To analyze the application effects of developed learning materials, divide students in four groups and lead them to make out their own creative products. In detail, guide students to make out their own report about mathematical themes that based on given learning materials. Concretely, build up the program to make up group report about their own topics in six weeks, after learning on various topics. Expert panel concluded that developed learning materials are successfully stimulate student's creativity in various way, after analyze of the student's activities. Moreover, those learning programs also contributed to the develop of the mathematical ability to thinking that necessary to writing a report. As well, four creative products are assessed as connote mathematically gifted student's creative thinking and meaningful elements in mathematical aspects.

• Journal of Educational Research in Mathematics
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• v.17 no.2
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• pp.179-199
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• 2007

The purpose of this study was to discover differences between mathematically gifted students (MGS) and non-gifted students (NGS) when making probability judgments. For this purpose, the following research questions were selected: 1. How do MGS differ from NGS when making probability judgments(answer correctness, answer confidence)? 2. When tackling probability problems, what effect do differences in probability judgment factors have? To solve these research questions, this study employed a survey and interview type investigation. A probability test program was developed to investigate the first research question, and the second research question was addressed by interviews regarding the Program. Analysis of collected data revealed the following results. First, both MGS and NGS justified their answers using six probability judgment factors: mathematical knowledge, use of logical reasoning, experience, phenomenon of chance, intuition, and problem understanding ability. Second, MGS produced more correct answers than NGS, and MGS also had higher confidence that answers were right. Third, in case of MGS, mathematical knowledge and logical reasoning usage were the main factors of probability judgment, but the main factors for NGS were use of logical reasoning, phenomenon of chance and intuition. From findings the following conclusions were obtained. First, MGS employ different factors from NGS when making probability judgments. This suggests that MGS may be more intellectual than NGS, because MGS could easily adopt probability subject matter, something not learnt until later in school, into their mathematical schemata. Second, probability learning could be taught earlier than the current elementary curriculum requires. Lastly, NGS need reassurance from educators that they can understand and accumulate mathematical reasoning.

• Journal of Educational Research in Mathematics
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• v.20 no.4
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• pp.459-476
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• 2010

The purpose of this study is to suggest a new direction in using LOGO as a gifted education program and to seek an effective approach for LOGO teaching and learning, by analyzing the strategic thinking of mathematically gifted elementary students. This research is exploratory and inquisitive qualitative inquiry, involving observations and analyses of the LOGO Project learning process. Four elementary students were selected and over 12 periods utilizing LOGO programming, data were collected, including screen captures from real learning situations, audio recordings, observation data from lessons involving experiments, and interviews with students. The findings from this research are as follows: First, in LOGO Project Learning, the mathematically gifted elementary students were found to utilize such strategic ways of thinking as inferential thinking in use of prior knowledge and thinking procedures, generalization in use of variables, integrated thinking in use of the integration of various commands, critical thinking involving evaluation of prior commands for problem-solving, progressive thinking involving understanding, and applying the current situation with new viewpoints, and flexible thinking involving the devising of various problem solving skills. Second, the students' debugging in LOGO programming included comparing and constrasting grammatical information of commands, graphic and procedures according to programming types and students' abilities, analytical thinking by breaking down procedures, geometry-analysis reasoning involving analyzing diagrams with errors, visualizing diagrams drawn following procedures, and the empirical reasoning on the relationships between the whole and specifics. In conclusion, the LOGO Project Learning was found to be a program for gifted students set apart from other programs, and an effective way to promote gifted students' higher-level thinking abilities.

• Journal of Elementary Mathematics Education in Korea
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• v.15 no.1
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• pp.179-198
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• 2011

The understanding of mathematical concepts should be backed up on a constant basis in oder to grow problem-solving skills which is one of the ultimate goals of math education. The purpose of the study was to provide readers with the information which could be considered valuably for the math educators trying both to prevent mathematical misconceptions and to develop curricular program by estimating the actual conditions and developing backgrounds of the mathematical misconceptions held by the gifted education learners. Accordingly, this study, as the first step, theoretically examined the meaning and the developing background of mathematical misconception. As the second step, this study examined the actual conditions of mathematical misconceptions held by the participant students who were enrolled in the CTY(Center for Talented Youth) program run by a university. The results showed that the percentage of the correct statements made by participant students is only 35%. The results also showed that most of the participant students belonged either to the level 2 requiring students to distinguish examples from non-examples of the mathematical concepts or the level 3 requiring students to recognize and describe the common nature of the mathematical concepts with their own expressions based on the four-level of concept formulation. The causes could be traced to the presentation of limited example, wrong preconcept, the imbalance of conceptual definition and conceptual image. Based on the estimation, this study summarized a general plan preventing the mathematical misconceptions in a math classroom.

• Journal of the Korea Society of Computer and Information
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• v.19 no.4
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• pp.149-158
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• 2014

The rapidly changing 21st-century knowledge and information society is emphasizing converged education that crosses various academic fields. In particular, the society expected the cultivation of the talent who balance scientific creativity and artistic sensitivity by adding arts to the existing converged education revolving around science and technology. However, at present, most STEAM education has been actively conducted with a focus on science and technology, whereas the subject of arts has been regarded or utilized as a supplementary means. Its problem is that the educational characteristics and values of art education have not been effectively utilized in educational terms and this could lead to superficial integrated education. In this respect, this study had the knowledge of various fields, such as science, technology, and mathematics, utilized usefully during the process of experiencing and creating arts. Accordingly, this study designed an education programs as with the case of Nam-Jun Baek who expanded the dominion of arts by creatively utilizing his own time's scientific technologies. In this educational process, the target program was developed in a manner that enables EPL to be utilized essentially as the study's knowledge-based tool and medium. The results of applying this educational program in 5th-grade elementary school students showed that the program has positive effects on the creative attributes of the students.