• Journal of Elementary Mathematics Education in Korea
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• v.16 no.1
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• pp.39-61
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• 2012

Mathematical creativity is essential in school mathematics and mathematics curriculum and ensures the growth of mathematical ability. Therefore mathematics educators try to develop students' creativity via mathematics education for a long time. In special, 2011 revised mathematics curriculum emphasizes mathematical creativity. Yet, it may seem like a vague characterization of mathematical creativity. Furthermore, it is needed to develop the methods for developing the mathematical creativity. So, the goal of this paper is to search for teaching and learning models for developing the mathematical creativity. For this, I discuss about issues of mathematical creativity and extract the factors of mathematical creativity. The factors of mathematical creativity are divided into cognitive factors, affective factors and attitude factors that become the factors of development of mathematical creativity in the mathematical instruction. And I develop 8-teaching and learning models for development of mathematical creativity based on the characters of mathematics and the most recent theories of mathematics education. These models make it crucial for students to develop the mathematical creativity and create the new mathematics in the future.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.121.5-121
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• 2001

For the last decade, remarkable progress in the coating weight uniformity of hot dip galvanized product has been made to overcome the tightening quality constraints and produce cost-effective galvanized products. This progress results from research and development works for more efficient air knife, more accurate model of coating process, more precise measurement of coating weight and more efficient control logics. The activities for an efficient mathematical model to predict coating weight and several control logics which has been implemented on the No.1 CGL, No. 2 CGL, and PGL at KwangYang Steel Works are reviewed in this article.

• Journal of Drive and Control
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• v.13 no.3
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• pp.1-7
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• 2016

A cold gas blow-down hydraulic actuation system is widely used in missiles that require an actuation system with a fast response time under a limited space with a short operating time and large loads on the actuators. The system consists of a pneumatic part that supplies the regulated high-pressure gas to a reservoir, and a hydraulic part that supplies pressurized hydraulic oil to the actuators by the pressurized gas in the reservoir. This paper proposes a mathematical model to analyze and simulate the pneumatic part of an actuation system that supplies the operating power to the actuators. The mathematical model is based on the ideal gas equation and also considers the models for heat transfer. The model is applied to the pressure vessel and the gas part of the reservoir, and the model for the pneumatic part is established by connecting the two models for the parts. The model is validated through a comparison of the simulation results with the experimental results. The comparison shows that the suggested model could be useful in the design of the pneumatic part of a cold gas blow-down type hydraulic actuation system.

• Journal of Ocean Engineering and Technology
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• v.29 no.6
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• pp.488-498
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• 2015

This paper presents the dynamic model of an AUV called HW200 for underwater surveillance. The mathematical model of HW200 is briefly introduced, considering its shape. The maneuvering coefficients were initially estimated using empirical formulas and a database of vehicles with similar shapes. A motion simulator, based on Simulink of Mathworks, was developed to evaluate the mathematical model of the vehicle and to tune the maneuvering coefficients. The parameters were finely tuned by comparing the experimental results and simulated responses generated with the simulator by applying the same control inputs as the experiment. The velocity of HW200 in the tuning process was fixed at a constant forward speed of 1.83 m/s. Simulations with variable speed commands were conducted, and the results showed good consistency in the motion response, attitude, and velocity of the vehicle, which were similar to those of the experiment even under the speed variation. This paper also discusses the feasibility of its application to a model-based integrated navigation system (INS) using the auxiliary information on the velocities generated by the model.

• Journal of ILASS-Korea
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• v.25 no.4
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• pp.178-187
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• 2020

The current emission regulations, US Tier-4 and EU Stage-V, are only able to satisfy the regulations when all currently mass-produced emission reduction technologies such as EGR, DOC, DPF, and SCR are applied. Therefore, in this study, for the application of the Urea-SCR system to non-road diesel engines, the database was established by measuring the NO, NO2 concentration and calculating the NO2/NOx ratio based on the catalyst temperature and exhaust mass flow rate. Also, based on the measured NO2/NOx ratio data, a mathematical model was proposed to predict the NO2/NOx ratio at SCR catalyst, and the suitability of the model was verified through steady-state and transient mode. As a result of comparing the NO2/NOx ratio measured at the DOC outlet under the steady-state condition to two model values separately, the R2 was 0.9811 for the 3D map model and 0.9303 for the mathematical model. And in the case of the NO2/NOx ratio measured at the DPF outlet, the R2 was 0.9797 for the 3D map model and 0.935 for the mathematical model. It was confirmed that the R2 with the model value of the 3D Map of the mathematical model in the transient mode is 0.957, which shows high reliability.

• Journal of Internet Computing and Services
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• v.9 no.5
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• pp.109-116
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• 2008

The rapid change of computer and Internet environments produces a lot of data of various quality, Because this fact affects enterprise and organization, it demands the level evaluation on data quality, Thus, we propose mathematical model for quality evaluation on the base of data quality in this paper. And we propose the analysis model(web evaluation model, DQnA)) that analyzes and maintains data quality.

• The Mathematical Education
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• v.56 no.3
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• pp.341-363
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• 2017

This case study contributes to the efforts on identifying the essential features of responsive teaching practice where students' mathematical thinking is central in instructional interactions. We firstly conceptualize responsive teaching as a type of teachers' instructional decisions based on noticing literature, and agree on the claim which teachers' responsive decisions should be accounted in classroom interactional contexts where teacher, students and content are actively interacting with each other. Building on this responsive teaching model, we analyze classroom observation data of a 7th grade teacher who implemented a lesson package specifically designed to respond to students' mathematical thinking, called Formative Assessment Lessons. Our findings suggest the characteristics of responsive teaching practice and identify the relationship between noticing and responsive teaching as: (a) noticing on students' current status of mathematical thinking by eliciting and anticipating, (b) noticing on students' potential conceptual development with follow-up questions, and (c) noticing for all students' conceptual development by orchestrating productive discussions. This study sheds light on the actual teachable moments in the practice of mathematics teachers and explains what, when and how to support teachers to improve their classroom practice focusing on supporting all students' mathematical conceptual development.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.89-93
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• 1989

In this paper, a mathematical engine model based on the actual engine operation is formulated to be adapted for the evalution and development of engine control system. In the model the classification of fuel paticle siza is considered. The model is simulated through the mathematical interpretation of intake manifold in the rapidly-accerated state. The spark-timing is analyzed with respect to engine r.p.m. The result shows that the model behaves similar performance to the actual engine operation and the spark-timing is very important to the characterization of engine r.p.m..

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.453-456
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• 2008

This study is underway to develop a prediction model for formwork pressure exerted by self-compacting concrete(SCC). Three major mechanisms related to formwork evolution over time were found, and mathematical modelling of each mechanism was made. A calculation method for real formwork pressure by using the mathematical formulae was also established. To verify predictive capability of the prediction model, a parametric study on parameters used in the model was performed. It was confirmed that the proposed model include the essential parameters that can simulate the real formwork pressure evolution over time.

• Proceedings of the Korean Association for Survey Research Conference
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• 2007.11a
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• pp.55-65
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• 2007

In this research, it will be examined on mathematical model of AMOS software program that ues for Covariance Structure Analysis. if we have not understood to mathematical model of Covariance Structure, we fail to understand Structural equation modeling. Similarly If We were not understand to mathematical model of AMOS Software, we do not use Software adequately. Therefore we examine two sorts of Software that be designed for Structural equation modeling or Covariance Structure Analysis. In this research, We will focus on 8 assumption of Structural equation modeling and compare AMOS(Analysis of MOment Structure) program with LISREL(Linear Structure RELation) program. We found that A Program of AMOS Software have materialized with RAM(Reticular Action Model).