• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.26 no.1
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• pp.23-48
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• 2022

In this paper, we provide predictive models for the market price of fruits, and analyze the performance of each fruit price predictive model. The data used to create the predictive models are fruit price data, weather data, and Korea composite stock price index (KOSPI) data. We collect these data through Open-API for 10 years period from year 2011 to year 2020. Six types of fruit price predictive models are constructed using the LSTM algorithm, a special form of deep learning RNN algorithm, and the performance is measured using the root mean square error. For each model, the data from year 2011 to year 2018 are trained to predict the fruit price in year 2019, and the data from year 2011 to year 2019 are trained to predict the fruit price in year 2020. By comparing the fruit price predictive models of year 2019 and those models of year 2020, the model with excellent efficiency is identified and the best model to provide the service is selected. The model we made will be available in other countries and regions as well.

• Journal of applied mathematics & informatics
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• v.40 no.5_6
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• pp.857-871
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• 2022

In this work, we formulated a mathematical model for divorce in marriage and extended in to an optimal control model. Firstly, we qualitatively established the model positivity and boundedness. Also we saw sensitivity analysis of the model and identified the positive and negative indices parameters. An optimal control model were developed by incorporating three time dependent control strategies (couple relationship education, reducing getting married too young & consulting separators to renew their marriage) on the deterministic model. The Pontryagin's maximum principle were used for the derivation of necessary conditions of the optimal control problem. Finally, with Newton's forward and backward sweep method numerical simulation were performed on optimality system by considering four integrated strategies. So that we reached to a result that using all three strategies simultaneously (the strategy D) is an optimal control in order to effectively control marriage divorce over a specified period of time. From this we conclude that, policymakers and stakeholders should use the indicated control strategy at a time in order to fight against Divorce in a population.

• East Asian mathematical journal
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• v.38 no.4
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• pp.497-516
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• 2022

In this study, we tried to devise a method to activate meta-affect in the aspect of supporting mathematics teaching and learning according to the need to find specific strategies and teaching and learning methods to activate learners' meta-affect in mathematics subjects, which are highly influenced by psychological factors. To this end, the definitional and conceptual elements of meta-affect which are the basis of this study, were identified from previous studies. Reflecting these factors, a teaching and learning model that activates meta-affect was devised, and a meta-affect activation strategy applied in the model was constructed. The mathematics teaching and learning model that activates meta-affect developed in this study was refined by verifying its suitability and convenience in the field through expert advice and application of actual mathematics classes. The developed model is meaningful in that it proposed a variety of practical teaching and learning methods that activate the meta-affect of learners in a mathematical learning situation.

• Journal of Educational Research in Mathematics
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• v.24 no.2
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• pp.227-251
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• 2014

In this study, we explored the preliminary model of multicultural mathematics teacher education to foster mathematics teachers' multicultural competencies. For the purpose, we investigated the multicultural competency of mathematics teachers with a survey questionnaire. We also interviewed mathematics teachers to analyze mathematics teachers' need of teacher education for multicultural mathematics education. In addition to the survey and the interview, we conducted a review of literatures to identify the principles, goals, contents, and methods for multicultural mathematics teacher education. In this research, we have identified 4 principles for multicultural mathematics teacher education: mathematics as culture, respecting diversity and equity, and identity. Under the principles, we presented 6 educational goals of teacher education for multicultural mathematics education. We chose the contents and the methods to promote the multicultural competency of mathematics teachers suitable for educational situation of Korean school. We integrated the principles, goals, contents and methods to design multicultural mathematics teacher education program for in-service teachers. Finally, we discussed the features and benefits of the preliminary model based on situational analysis for multicultural mathematics teacher education. We proposed that follow-up study is necessary to investigate the effect of the model for the future development of multicultural mathematics teacher education model.

• The Mathematical Education
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• v.54 no.2
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• pp.195-206
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• 2015

The purpose of this study is to examine the effects of teacher on fourth-grade students' attitudes toward mathematics using data from TIMSS 2011. Students' attitudes toward mathematics included interest in learning mathematics, interest in mathematics lessons, and confidence in their mathematics ability. Teacher factors included mathematics professional development, confidence in teaching mathematics, teacher-centered mathematics instruction, and enhancing student mathematical thinking. The two level Hierarchical Linear Model was employed to analyze the relationship between teacher factors and student attitudes. Results showed that teacher-centered mathematics instruction significantly and positively predicted students' confidence about their mathematics ability. The findings suggest that school systems and mathematics educators need to provide teachers with the curriculum, assessment, and research-based practices and knowledge to overcome the obstacles to change their mathematics classroom.

• Research in Mathematical Education
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• v.27 no.1
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• pp.129-150
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• 2024

This study utilized South Korean elementary and middle school student data to examine the longitudinal change trajectories of learning motivation types according to the longitudinal change trajectories of mathematics academic achievement. Growth mixture modeling, latent growth model, and multiple indicator latent growth model were used to examine various change trajectories for longitudinal data. As a result of the analysis, it was classified into 4 subgroups with similar longitudinal change trajectories of mathematics academic achievement, and the characteristics of the mathematics subject, which emphasize systematicity, appeared. Furthermore, higher mathematics academic achievement was associated with higher self-determination and higher academic motivation. And as the grade level increases, amotivation increases and self-determination decreases. This study suggests that teaching and learning support using this is necessary because the level of learning motivation according to self-determination is different depending on the level of mathematics academic achievement reflecting the characteristics of the student.

• Journal of applied mathematics & informatics
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• v.41 no.1
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• pp.11-31
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• 2023

The paper presents a critical analysis of selected topics related to the modeling of interacting species in which prey has nonlinear reproduction, which is in competition with predator. The mathematical model's stochastic stability is investigated. The method of designing appropriate Lyapunov functions is used to identify permanence conditions among the parameters of the model and conditions for the structure to no longer be extinct. The system's two-dimensional diffusive stability is regarded and studied. The system experiences the process of saddle-node bifurcation by varying the death rate of predator parameter. Further effects of parameters that undergo inherent oscillations are numerically investigated, revealing that as the intensity of predation parameter b is increased, the device encounters non-periodic and damped oscillations.

• Research in Mathematical Education
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• v.26 no.3
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• pp.147-166
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• 2023

Mathematics is a science of pattern. Mathematics is a subject of inquiring which aims at discovering the models hidden behind the world. Pattern is abstraction and generalization of the model. Mathematical pattern is a higher level of mathematical model. Mathematics patterns are often hidden in pattern similarity. Creation of mathematics lies largely in discovering the pattern similarity among the various components of mathematics. Inquiring is the core and soul of mathematics teaching. It is very important for students to study mathematics like mathematicians' exploring and discovering mathematics based on pattern similarity. The author describes an example about how to guide students to carry out mathematics inquiring based on pattern similarity in classroom.

• Korean Journal of Mathematics
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• v.22 no.4
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• pp.599-609
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• 2014

We refer to the saturation assumptions on the finite element approximation for a one dimensional convection-diffusion model. By examining piecewise linear finite elements with refined mesh by half and hierarchical bases, we verify the saturation results, respectively.

• Journal of applied mathematics & informatics
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• v.8 no.3
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• pp.1001-1007
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• 2001

In this paper, we show the existence of securities protfolio in security model with influx and find the non-arbitrage class of protfolios.