• Journal of Magnetics
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• v.1 no.2
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• pp.55-56
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• 1996

The effective magnetic moment of Cr$_2$O$_3$is determined by assuming that a proportional relation holds between its moment and the effective magnetic moment of hematite determined by the previous derived relaxation expression and the moments of Fe3+ ion and Cr3+ ion. The result obtained from the relation is found to be given by 0.10 in Bohr magneton which is in good agreement with the value obtained by use of the expression.

• School Mathematics
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• v.15 no.4
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• pp.723-742
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• 2013

The purpose of this study was to analyze children's proportional reasoning process on an ill-structured "architectural drawing" problem solving and to investigate their level and characteristics of proportional reasoning. As results, they showed various perspective and several level of proportional reasoning such as illogical, additive, multiplicative, and functional approach. Furthermore, they showed their expanded proportional reasoning from the early stage of perception of various types of quantities and their proportional relation in the problem to application stage of their expanded and generalized relation. Students should be encouraged to develop proportional reasoning by experiencing various quantity in ration and proportion situations.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.5 s.176
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• pp.1352-1361
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• 2000

We obtain a micromechanics-based Helmholtz free energy and then in the framework of irreversible thermodynamics, a kinetic relation, a martensitic nucleation criterion and the reorientation criterion of martensitic variants are obtained. These relations are valid for a three-dimensional proportional and non-proportional loadings and for a combination of mechanical and thermal loading. From the simulated pseudoelastic stress-strain relation of a single crystal with loading rate effect, polycrystalline behavior in case of proportional and non-proportional loading is predicted by a homogenization method. The obtained results are compared quantitatively with experimental results.

• Journal of the Korean Society of Industry Convergence
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• v.6 no.3
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• pp.185-192
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• 2003

This study consolidation undrain Triaxial Compression Tests using constant confining pressure in clay that receive preconsolidation stress that is different and, void ratio, pore water pressure coefficient, shear strength compare with another thing theory and studied analyzing change relation of elastic modules. The summary of analysis is follows: If preconsolidation stress increases in same confining stress in relation of preconsolidation stress and deviator stress, deviator stress is proportional and increased. Can know that excess void pressure is proportional and decreases in size of preconsolidation stress in same confining stress state if preconsolidation stress increases preconsolidation stress and relation of excess void pressure. Also, over consolidated state can assume that this is thing by Dilatancy's effect though excess void pressure decreased remarkably. Preconsolidation stress and relation of stress path can know that shear strength degree increases preconsolidation stress increases, and specially, preconsolidation stress was appear in stress path form of overconsolidated state case of clay that receive at 300, 400, 500kPa in 100, 150kPa's deviator stress.

• The Mathematical Education
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• v.46 no.2 s.117
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• pp.141-153
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• 2007

The purpose of the study is to analyze children's proportional reasoning and problem solving in proportional problems with/without iconic representations. Proportional problems include 3 tasks such as (a) without any picture, (b) with simple picture, and (c) with/without iconic representation. As a result, children didn't show any significant differences in two tasks such as (a) and (b). However, children showed better proportional reasoning with iconic representation. In addition, 'build-up expression' strategy was used mostly in solving problems and 'additive strategy' was shown as an error which students didn't make an appropriate proportional relation expression and they made a wrong additive strategy.

• Journal of Elementary Mathematics Education in Korea
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• v.21 no.4
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• pp.599-620
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• 2017

In this study, we analyzed how the speed concept has been handled in Korean elementary mathematics textbooks and suggested some didactical implications for revising the teaching of speed concept. To do this, we investigated the curriculum documents, textbooks and teacher's manuals from the first curriculum to the 2009 revision curriculum. The results show that the speed concept of the elementary mathematics in Korea has been based on the concept of average speed and that the approach of applying the value of ratio has been strengthening more than the aspect of proportional relation. So we suggested two didactical suggestions: 1) the teaching of the speed concept should start with uniform movements. 2) the reasoning of proportional relation should be more strengthened.

• The Journal of Korean Medicine
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• v.29 no.5
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• pp.90-95
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• 2008

Objectives : The purpose of this study is to evaluate if there is significant correlations between the angle of costal arch and digestion, and BMI(Body Mass Index). Methods : To know the correlation between digestion and the angle of costal arch, we hand-measured the angle of costal arch and made questionnaire about digestion. We analysed the data with Pearson product-moment correlation analysis using SPSS 12.0. Results : There is proportional correlation between the angle of costal arch and digestion. Also wider costal arch shows better appetite, faster speed of eating and more quantity of meal. And someone having wider costal arch has less digestion disorder after eating heavy foods or being anxious. And there is proportional relation between angle of the angle of costal arch and BMI. Conclusions : There is significant correlation between the angle of costal arch and digestion as wider costal arch can digest better. Also it has proportional relation between the angle of costal arch and BMI. We expect that further study about morphology of abdomen will develop our abdominal examination and diagnostic methods.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.207-214
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• 1997

Strength experimental on mortar which use Quenched Blast-Furnace Slag as aggregate was carried our for a fundamental study of application possibility of Quenched Blast-Furnace Slag as aggregate. It gives the following results. The strength of mortar use Quenched Blast-Furnace Slag is decrease as substitution rate is higher. As W/C rate increase, the strength decrease, but the strength decrease of fine aggregate rate 1:3 is lower than 1:2. The relation with fine aggregate is that the amount of fine aggregate is inversely proportional to strength. Th relation with age is proportional to strength and strength rate of going is lower than general mortar in 28 age the change of strength proportionately with W/C rate is that as W/C rate increases, th strength is drop ; it shows that it has same tendency as general mortar sand or crushed sand, but while W/C rate increase the strength is as high as general mortar. The reason can be assumed that water content per unit needed to Quenched Blast-Furance Slag is more than in case of sand. In addition, the relation with substitution rate is that the strength is the strongest at substitution rate 25% and 50% ; that is , sometimes it is higher than mortar which use sand 100%. In addition, long age strength of mortar which use Quenched Blast-Furnace Slag as aggregate is about to be studied in the last.

• School Mathematics
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• v.19 no.2
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• pp.229-248
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• 2017

This study investigated the factors that should be considered when teaching proportional expression and proportional distribution through literature review. Based on these results, we analyzed and compared Korean and foreign mathematics textbooks on proportional expression and proportional distribution longitudinally and horizontally to search for desirable methods of organizing the unit of proportional expression and proportional distribution in mathematics textbooks. For longitudinal analysis, we took the mathematics textbooks according to the national curriculum since the 5th one. For horizontal analysis, we selected the mathematics textbooks of Japan, Singapore, and China. In each textbook, the contents and the order in relation to proportional expression and proportional distribution, the definitions of terminology, and the contexts and the visual representations for introducing related concepts are selected as the analysis framework. The results of analysis revealed many characteristics and the differences in ways of dealing contents about proportional expression and proportional distribution. Based on these results, we suggested some implications for writing the unit of proportional expression and proportional distribution in elementary mathematics textbooks.

• Journal of Educational Research in Mathematics
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• v.25 no.1
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• pp.21-58
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• 2015

The aim of this study is to look into the didactical background for teaching proportional reasoning in elementary school mathematics and offer suggestions to improve teaching proportional reasoning in the future. In order to attain these purposes, this study extracted and examined key ideas with respect to the didactical background on teaching proportional reasoning through a theoretical consideration regarding various studies on proportional reasoning. Based on such examination, this study compared and analyzed textbooks used in the United States, the United Kingdom, and South Korea. In the light of such theoretical consideration and analytical results, this study provided suggestions for improving teaching proportional reasoning in elementary schools in Korea as follows: giving much weight on proportional reasoning, emphasizing multiplicative comparison and discerning between additive comparison and multiplicative comparison, underlining the ratio concept as an equivalent relation, balancing between comparisons tasks and missing value tasks inclusive of quantitative and qualitative, algebraic and geometrical aspects, emphasizing informal strategies of students before teaching cross-product method, and utilizing informal and pre-formal models actively.