• The Mathematical Education
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• v.50 no.2
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• pp.165-184
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• 2011

The purpose of this study is to detect the possibility of the development of conception of a graph and the formula with the absolute value through context questions, and also to investigate the effectiveness of the each step of the mathematical modeling activities in helping students to have the conception. The research was conducted to analyze the process of development of the mathematical conception by applying the mathematical modeling activities two times to subjects of two academic high school students in the first grade. The results of the study are as follows: Firstly, the subjects were able to comprehend the geometric conception of the absolute value and to make the graph and the formula with the sign of the absolute value by utilizing the condition of the question. Secondly, the researcher set five steps of the intentional mathematical model in order to arouse the effective mathematical notion and each step performed a role in guiding the subjects through the mathematical thinking process in consecutive order; consequently, it was efficacious in developing the conception.

• Journal of the Korean Operations Research and Management Science Society
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• v.19 no.2
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• pp.57-73
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• 1994

KADS is currently a best known methodology for expert system development is Europe. KADS world sees the expert system development as a modeling activity and uses models to control complexity of the development process. Four layers KADS expertise model is used to describe expert knowledge. But this expertise model in high abstraction level is conceptual and not formalized. This paper has formalized KADS expertise model using set theory and mathematical semantics combined in order to reduce the ambiguity of informal models of expertise, provide a precise means of communication about the model of expertise and point out incompleteness and inconsistency of the model of expertise. Instead of first order predicate calculs, set theory and mathematical semantics are used because they are a more general and have compositive quality.

• Korean Journal of Computational Design and Engineering
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• v.2 no.1
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• pp.11-18
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• 1997

Scientific volume visualization addresses the representation, manipulation, and rendering of volumetric data sets, providing mechanisms for looking closely into structures and understanding their complexity and dynamics. In the past several years, a tremendous amount of research and development has been directed toward algorithms and data modeling methods for a scientific data visualization. But there has been very little work on developing a mathematical volume model that feeds this visualization. Especially, in flow visualization, the volume model has long been required as a guidance to display the very large amounts of data resulting from numerical simulations. In this paper, we focus on the mathematical representation of volumetric data sets and the method of extracting meaningful information from the derived volume model. For this purpose, a B-spline volume is extended to a high dimensional trivariate model which is called as a flow visualization model in this paper. Two three-dimensional examples are presented to demonstrate the capabilities of this model.

• Proceedings of the KWS Conference
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• 1997.10a
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• pp.229-233
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• 1997

The demand to increase productivity and quality, the shortage of skilled labour and the strict health and safety requirements have led to the development of the automated welding process to deal with many of the present problems of welded fabrication. To make effective use of the automated arc welding process, it is imperative that a mathematical model, which can be programmed easily and fed to the robot, should be developed. The objectives of the paper are to develop the mathematical equations (linear and curvilinear) for study of the relationship between process variables and bead geometry by employing a standard statistical package program, SAS and to choose the best model for automation of the $CO_2$ gas arc welding process. Mathematical models developed from experimental results can be employed to control the process variables in order to achieve the desired bead geometry based on weld quality criteria. Also these equations may prove useful and applicable for automatic control system and expert systems.

• Management Science and Financial Engineering
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• v.5 no.1
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• pp.27-49
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• 1999

WebME is an Web-based integrated modeling environment that implements a multi-facetted modeling approach to mathematical model representation and management. Key features of WebME include the following: (i) sharing of modeling knowledge on the Web, (ii) a user-friendly interface for creating, maintaining, and solving models, (iii) independent management of mathematical models from conceptual models, (iv) object-oriented conceptual blackboard concept, (v) multi-facetted mathematical modeling modeling, and (vi) declarative representation of mathematical knowledge. This paper presents details of design and implementation issues that were encountered in the development of WebME.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.4
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• pp.349-357
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• 2017

If an actuation system of the tactical missile is required very fast response time on conditions of short operating time and big loads on the actuator, we would prefer to adopt a small hydraulic system. In this paper, a mathematical model is proposed to analyze and simulate the small hydraulic actuation system. The mathematical model consists of a high pressure vessel model, a pressure regulator model, a hydraulic reservoir model and a actuator model. The suggested model is validated by comparison of simulation results with experimental data. The simulation results show that the mathematical model could be useful for designing a hydraulic actuation system.

• Journal of Biosystems Engineering
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• v.20 no.3
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• pp.275-287
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• 1995

The rice processing complex(RPC) consisted of the rice handling, drying, storage, and milling processes. It has been established at 83 locations domestically by April 1994, and 200 of RPC will be built more throughout the country. Therefore, this study has been performed to achieve two objectives as the followings : 1) Development of mathematical models which can assess the requirement of electricity, fuel, and labor for four model systems of rice processing complex. 2) Development of a computer simulation model which produce the improved designs of RPC by the evaluation results of energy requirements of four RPC models. The results from this study are summarized as follows : 1) Mathematical models were developed on the basis of result of mass balance analysis and required power of machines for each process. 2) A computer simulation model was developed, which can produce the improved designs of RPC by the evaluation results of energy requirements. The computer simulation model language was BORLAND $C^{++}$. 3) The results of simulation showed that total energy requirements were ranged from 75.94㎾h/t to 124.30㎾h/t. 4) From the results of computer analysis of energy requirement classified by drying type, it was found that energy requirement of the drying type A{paddy rice (PR) for storage-natural air drying(15%), PR for milling-heated air drying(16%)} were less than that of the drying type B{1 step-natural air drying(PR for storage : 18%, PR for milling : 20%), 2 step-heated air drying(PR for storage : 15%, PR for milling : 16%)}. 5) The energy efficient drying method is that all the incoming rough rice to RPC should be dried by national air drying systems. If it is more than the capacity of national air drying system, the amount of surplus rough rice is recommended to be dried by the heated air drying method.

• Transactions of Materials Processing
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• v.28 no.4
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• pp.190-196
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• 2019

The capability of accurately predicting the roll force profile across a strip in the bite zone in cold rolling process is vital for the calculation of strip profile. This paper presents a derivation of a precision mathematical model for predicting variations in the roll force across a strip in cold rolling. While the derivation is based on an approximate 3-D theory of rolling, this mathematical model also considers plastic deformation in the pre-deformation region which is located close to the roll entrance before the strip enters the bite zone. Finally, the mathematical model is expressed as a boundary value problem, and it predicts the roll force profile and tension profile in addition to lateral plastic strain profile.

• Journal of Biosystems Engineering
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• v.12 no.3
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• pp.17-29
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• 1987

A 10-degree of freedom mathematical model of motion for power tiller-trailer system was developed. This model can predict motion characteristics of power tiller trailer system while travelling over smooth and irregular ground surfaces under various operating conditions. The model provide, the fundamental data needed to improve the stability of power tiller-trailer systems.

• Communications of Mathematical Education
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• v.27 no.3
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• pp.221-248
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• 2013

Among five types of the model textbook based on storytelling, the type of 'Inquiry into history of Mathematics' focuses on adapting the logic of mathematical discovery to the organization of mathematical contents. It enables students to recognize that mathematics has been developed by human needs and creativity while they are engaged in the story about knowledge formation. Moreover the textbook offers the context in which students are able to understand mathematical insights and logics hidden in the subject matter, so that they can reinvent and develop mathematical knowledge. In this study, we found the principles for development of the textbook based on storytelling for 'Inquiry into History of Mathematics' by analyzing the chapter about 'Complex number and Quadratic Equations' of the model textbook. The chapter was implemented in classroom environment and students' understanding of the subject matter and their perception on the textbook based on storytelling were surveyed before and after the implementation. The results showed the possibilities of adapting the textbook based on storytelling and we suggested some implications for further development.