• Education of Primary School Mathematics
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• v.19 no.4
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• pp.277-289
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• 2016

Fraction is one of the concepts which are difficult to elementary school students. So, many researches about fraction were performed in mathematics education research. In special, fraction has so many subordinative concepts-proper fraction, improper fraction, mixed number. We have to concentrate on the conceptual understanding in teaching of fraction. In this case, a mixed number and improper fraction are concepts which can convert respectively. And there are methods that a mixed number and improper fraction can be converted. So, it's needed to analyze the converting methods in textbooks for getting the implication of teaching in this areas. In this study, I analyzed the Korean and foreign's textbooks. I certified the methods-using addition expression, using part-whole model in the textbooks. For the conceptual understanding, I suggested to use the fusion of the various part-whole fraction models and addition expression more than the algorithm in converting between a mixed number and improper fraction. It's reason that the use of models in converting between a mixed number and improper fraction is important for the relational understanding.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.6
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• pp.49-56
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• 2010

This study was conducted to find out the best optimum design method for the design of reinforced concrete agricultural aqueduct abutment and pier structures. The mixed-discrete optimization and continuous optimization method were applied to the design of reinforced concrete agricultural aqueduct abutment and pier and the results of these optimization methods were compared each other. It is proved that mixed-discrete optimization method is more reliable, efficient and reasonable than continuous optimization method for the optimum design of the reinforced concrete agricultural aqueduct abutment and pier.

• Journal of Korean Society for Quality Management
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• v.44 no.4
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• pp.799-811
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• 2016

Purpose: The conjoint analyst in marketing are interested in detecting whether there exist synergy or antagonistic effects between two attributes. In the cases where attributes have two or three levels, we research on the design of survey questionnaire to estimate all the main effect and as many two factor interaction effects as possible. Methods: We consider the balanced incomplete block (BIB) mixed level factorial design $2^f{\times}3^g$ or fractional factorial design. To reduce the number of questions in a questionnaire, we propose the balanced incomplete block mixed level design with minimum aberration which is generated by implementing proc factex in SAS. Also, we propose using two or three level BIB factorial design instead of mixed level designs by transforming three level attributes into two attributes of two levels and two level attribute into three level attribute by using dummy level technique. Results: We propose three methods for designing survey questionnaire where the block and design generators are found with practical number of questions in a questionnaire. By analyzing all the respondents survey data generated by the simulation study, we find the proper model and do the concepts optimization. Conclusion: The proposed methods of designing survey questionnaires seem to perform well in the sense that the proper model, and then the optimal concept is found in a case study where all the respondents survey data are generated by the simulation study.

• Journal of Korean Academy of Nursing
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• v.45 no.4
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• pp.501-512
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• 2015

Purpose: The purpose of this study, which was guided by the Resiliency Model of Family Stress, Adjustment, and Adaptation, was twofold: (a) to explore family and parental adaptation and factors influencing family adaptation in Korean families of children with Down syndrome (DS) through a quantitative methodology and (b) to understand the life with a Korean child with DS through a qualitative method. Methods: A mixed-methods design was adopted. A total of 147 parents of children with DS completed a package of questionnaires, and 19 parents participated in the in-depth interviews. Quantitative and qualitative data were analyzed using stepwise multiple regression and content analysis respectively. Results: According to the quantitative data, the overall family adaptation scores indicated average family functioning. Financial status was an important variable in understanding both family and parental adaptation. Family adaptation was best explained by family problem solving and coping communication, condition management ability, and family hardiness. Family strains and family hardiness were the family factors with the most influence on parental adaption. Qualitative data analysis showed that family life with a child with DS encompassed both positive and negative aspects and was expressed with 5 themes, 10 categories, and 16 sub-categories. Conclusion: Results of this study expand our limited knowledge and understanding concerning families of children with DS in Korea and can be used to develop effective interventions to improve the adaptation of family as a unit as well as parental adaptation.

• Journal of the Korean Geotechnical Society
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• v.16 no.2
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• pp.79-89
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• 2000

The application of stabilization method has increased because of short construction periods, no environmental problems with dumped and replaced soil, assurance of required strength and economical effect with mid to small size construction. The unconfined and triaxial(UU-condition) compression tests were executed with each mixing sample for the study of the improvement effects and the effect of design-parameters by the stabilization methods. Three typical stabilizers, which are representative in Korea, were applied in this study, and three common soils(very soft clay, general weathered soil, common clay), which are common in Korea, were used in this study. In this study, the effect of engineering factors(soils, stabilizers and water contents, etc.) which are important parameters for the improvement effects of mixed ground by stabilizers, was analyzed. As results, the tendencies of design-parameters(unconfined compression strength, deformation modulus and strength parameter) are presented and the criteria of the application of stabilization methods are suggested.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.257-262
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• 2001

There are only a few tests to ensure concrete quality before placing in domestic situ; One is slump test for workability, the other is air content test for durability, the concrete compressive strength which is one of important factors to influence on concrete Quality has been tested after 28 days placing. Methods on early judgement of concrete strength have been introduced for concrete quality management, but such methods are time consuming, expensive, and required special expertise. Therefore, these have difficulty in situ application for concrete management. This study aimed at reviewing application of estimated equation of compressive strength as means for ready-mixed concrete, making an estimated equation which enables to estimate 28 days compressive strength by using regression formula analysis on basis of mixing designs of ready mixed concrete and results of compressive strength.

• Communications for Statistical Applications and Methods
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• v.15 no.4
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• pp.587-595
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• 2008

Parallel coordinate plot of Inselberg (1985) is useful for visualizing dozens of variables, but so far the plot's applicability is limited to the variables of numerical type. The aim of this study is to extend the parallel coordinate plot so that it can accommodate both numerical and categorical variables. We combine Hayashi's (1950, 1952) quantification method of categorical variables and Hurley's (2004) endlink algorithm of ordering variables for the parallel coordinate plot. In line with our former study (Kwak and Huh, 2008), we develop Andrews' type modification of conventional straight-lines parallel coordinate plot to visualize the mixed-type data.

• Journal of Korean Society for Geospatial Information Science
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• v.3 no.2 s.6
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• pp.91-100
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• 1995

The aim of this study is to classify mixed information in a pixel of a remote sensing image data (in the case of SPOT HRV's band $1{\sim}3,\;20m{\times}20m$). First, the loss of information and the uncertainty of mixed pixel are examined. To solve the problems, methods by fuzzy sigmoid function and back-propagation neural network are suggested. Then. the study simulates and comparatively analyzes the two methods.

• Journal of applied mathematics & informatics
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• v.23 no.1_2
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• pp.183-191
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• 2007

In this paper, we introduce and study a new class of equilibrium problems, known as regularized mixed quasi equilibrium problems. We use the auxiliary principle technique to suggest and analyze some iterative schemes for regularized equilibrium problems. We prove that the convergence of these iterative methods requires either pseudomonotonicity or partially relaxed strongly monotonicity. Our proofs of convergence are very simple. As special cases, we obtain earlier results for solving equilibrium problems and variational inequalities involving the convex sets.

• Journal of the Korean Mathematical Society
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• v.47 no.6
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• pp.1107-1122
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• 2010

In this paper, we shall use analytic methods to study the hybrid mean value involving the mixed two-term exponential sums C(m, n, r, $\chi$; q), and give several sharp asymptotic formulae.