• Geomechanics and Engineering
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• v.20 no.2
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• pp.87-101
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• 2020

The construction of combined pile-raft foundations is considered as the main option in designing foundations in high-rise buildings, especially in soils close to the ground surface which do not have sufficient bearing capacity to withstand building loads. This paper deals with the geotechnical report of the Northern Fereshteh area of Tabriz, Iran, and compares the characteristics of the single pile foundation with the two foundations of pile group and geogrid. Besides, we investigate the effects of five principal parameters including pile diameter and length, the number of geogrid layers, the depth of groundwater level, and pore water pressure on vertical consolidation settlement and pore water pressure changes over a year. This study assessed the mechanism of the failure of the soil under the foundation using numerical analysis as well. Numerical analysis was performed using the two-dimensional finite element PLAXIS software. The results of fifty-four models indicate that the diameter of the pile tip, either as a pile group or as a single pile, did not have a significant effect on the reduction of the consolidation settlement in the soil in the Northern Fereshteh Street region. The optimum length for the pile in the Northern Fereshteh area is 12 meters, which is economically feasible. In addition, the construction of four-layered ten-meter-long geogrids at intervals of 1 meter beneath the deep foundation had a significant preventive impact on the consolidation settlement in clayey soils.

• Communications of Mathematical Education
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• v.22 no.3
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• pp.253-273
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• 2008

The key feature of the $7^{th}$ Education curriculum, which is applied by order by year from 2000, is represented by differentiated curriculum. In order to embody differentiated curriculum, it is extensively recommended the level-based instruction. Level-based class basically has purposes to give students matched study experiences in accordance with their abilities and to help all students to understand what they have learned through providing differentiated instruction with considering the learners' stand points. The preceding researches have reported many cases about operating methods and educational effectiveness for the level-based instruction. In the meantime, researches about students' acceptances or opinions related to the level-based instruction are not sufficient. In this research, students opinions about level-based instruction are analyzed, based on the distinction of sex and level, and improving operational methods are suggested.

• Research in Mathematical Education
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• v.22 no.4
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• pp.261-282
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• 2019

The research related to testing pupils' achievement in the field of Measurement and Measure in initial teaching of geometry points to an insufficient adoption of the basic components of the length measurement concept among pupils. In order to discover the cause, we looked at the basic components on which the procedure of measuring length using a ruler is based, highlighted the possibilities of introducing the procedure in measuring length, and determined pupils' achievement during the procedure of measuring length using a ruler. The research sample consisted of 145 pupils, out of which 72 were the 2^nd grade pupils and 73 were the 4^th grade pupils. A descriptive method was applied in the research. The technique we used was testing, and for the statistical data processing we used a χ² test. The results of the research show that, when drawing a straight line of a given length using a ruler, there is no statistical difference in achievement between the 2^nd and 4^th grade pupils, nor in the pupils' knowledge regarding drawing a ruler independently, while drawing a straight line of a given length using a "broken" ruler 4^th grade pupils are statistically better. The results of the research indicate that pupils' achievement is better in doing standard tasks than in non-standard ones, given that the latter require conceptual knowledge. The components of the concept of length measurement using ruler have not been sufficiently developed yet, and these include: zero-point, partitioning a measured object in a series of consecutive measurement units and their iteration. We shed more light on the critical stage in the procedure of length measurement - the transition from non-standard to standard units and the formation of the length measurement scale. For further research, we propose to look at the formation of the concept of length measurement using the ruler through all its components and their inclusion in the mathematics curriculum, as well as examining the correlation of pupils' achievement in the procedure of measuring length with their achievement in measuring area (and volume).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.271-274
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• 2013

Considering the recent trend highlighting the importance of STEAM education, the purpose of this study is to develop scientific research activities and STEAM technology material using the smart device sensor. Drawing a picture on a map with GPS drawing application which contains elements such as IT, geographic information, sports and arts, we intent not just to install a smartphone application but also to get synergic effects and help with real cartography and geographic classes which are not experienced in the middle school curriculum, by using the functions of a smart device. Through the development of STEAM teaching material, we intended to provide a clear direction towards advancement by developing creative teaching data and teaching models which encourage students to improve their interest and creativity in science, technology, engineering, art, and mathematics.

• Transactions on Electrical and Electronic Materials
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• v.16 no.3
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• pp.130-134
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• 2015

This research proposes the use of a composition modulated (ZrO₂)_x(Al₂O₃)_1-x film as a charge trapping layer for charge trap flash memory; this is possible when the Zr (Al) atomic percent is controlled to form a variable bandgap as identified by the valence band offsets and electron energy loss spectrum measurements. Compared to memory devices with uniform compositional (ZrO₂)_0.1(Al₂O₃)_0.9 or a (ZrO₂)_0.92(Al₂O₃)_0.08 trapping layer, the memory device using the composition modulated (ZrO₂)_x(Al₂O₃)_1-x as the charge trapping layer exhibits a larger memory window (6.0 V) at the gate sweeping voltage of ±8 V, improved data retention, and significantly faster program/erase speed. Improvements of the memory characteristics are attributed to the special energy band alignments resulting from non-uniform distribution of elemental composition. These results indicate that the composition modulated (ZrO₂)_x(Al₂O₃)_1-x film is a promising candidate for future nonvolatile memory device applications.

• Journal of The Korean Association of Information Education
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• v.22 no.3
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• pp.367-374
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• 2018

In order to cultivate the human resources needed in the 4th industrial revolution era, it is necessary to select the gifted students and educate them systematically. Although excellent gifted students are important in a specific field, more convergent talents in the fields of mathematics, science, and information are required. The purpose of this study is to investigate how evaluation factors reflecting the characteristics of information gifted students affect the selection of science gifted students of a university gifted education center. In the characteristics of information gifted students, the cognitive factors such as Rule creation ability, Reasoning ability, Efficiency ability, Generalization ability, Structuring ability and Abstraction ability were highly correlated in selecting the science gifted students. Correlations in the applicants group of students for science gifted education center are higher than those in the first passers group and higher than those in the final successful candidates group. This means that the factors that shows the characteristics of the information gifted have a great influence on the selection of the science gifted.

• Journal of The Korean Association of Information Education
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• v.23 no.6
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• pp.543-550
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• 2019

In 2006, Janet Wing defined computational thinking and operated SW education as a formal curriculum in the UK in 2013. This study collected related research papers by using computational thinking, which has recently increased in importance, and analyzed it using text mining. In the first, CONCOR analysis was conducted with the keyword of computational thinking. In the second, text mining of the components of computational thinking was selected by the repr23esentative academic journals at domestic and foreign. As a result of the two-time analysis, first, abstraction, algorithm, data processing, problem decomposition, and pattern recognition were the core of the study of computational thinking component. Second, research on convergence education centered on computational thinking and science and mathematics subjects was actively conducted. Third, research on computational thinking has been expanding since 2010. Research and development of the classification and definition of computational thinking and components and applying them to education sites should be conducted steadily.

• Journal of The Korean Association For Science Education
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• v.21 no.2
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• pp.328-341
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• 2001

The purpose of this study was to analyze the achievements in science results of the TIMSS-R test, which was performed in 1999 with 38 nations participating. In this study, general trends in international science achievement considering the differences beween nation, content areas, and gender were analyzed through descriptive statics. The average scale score of Korean 8th grades students was 549, which was significantly higher than international average of 488. However it showed a relative decline from 4th grade in TIMSS to 8th grade in TIMSS-R. Chinese Taipei and Singapore students had the highest average performance, followed by Hungary, Japan, and Korea. The average gender differences of Korean students showed a decrease from TIMSS in 1995 to TlMSS-R in 1999, but it was still significantly higher than the international average. The average differences of overall science and each content area were not statistically significant both internationally and domestically.

• 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.26 no.2
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• pp.9-13
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• 1988

Mathematics education is generally to cultivate mathematical thought. Most meaningful thought is to solve a certain given situation, that is, a problem. The aim of mathematies education could be identified with the cultivation of mathematical problem-solving ability. To cultivate mathematical problem-solving ability, it is necessary to study the nature of mathematical ability and its aspects pertaining to problem-solving ability. The purpose of this study is to investigate the relation between problem-solving ability and classficational viewpoint of mathematical verbal problems, and bet ween the detailed abilities of problem-solving procedure and classificational viewpoint of mathematical verbal problems. With the intention of doing this work, two tests were given to the third-year students of middle school, one is problem-solving test and the other classificational viewpoint test. The results of these two tests are follow ing. 1. The detailed abilities of problem-solving procedure are correlated with each other: such as ability of understanding, execution and looking-back. 2. From the viewpoint of structure and context, students classified mathematical verbal problems. 3. The students who are proficient at problem-solving, understanding, execution, and looking-back have a tendency to classify mathematical verbal problems from a structural viewpoint, while the students who are not proficient at the above four abilities have a tendency to classify mathematical verbal problems from a contextual viewpoint. As the above results, following conclusions can be made. 1. The students have recognized at least two fundamental dimensions of structure and context when they classified mathematical verbal problems. 2. The abilities of understanding, execution, and looking- back effect problem-solving ability correlating with each other. 3. The instruction emphasizing the importance of the structure of mathematical problems could be one of the methods cultivating student's problem-solving ability.