• Communications of Mathematical Education
• /
• v.27 no.4
• /
• pp.407-428
• /
• 2013

The purpose of this research is to develop an effective teaching-learning model and suggest efficient methods for improving the learning abilities in mathematics of the students of engineering college. For this purpose, we examined their learning styles and learning attitudes toward Mathematics, which are important factors in teaching-learning process, and analyzed the relation between them. As a result, we found that participants had a disposition of being dependent and highly participating, so we made an effort to develop a teaching-learning model which can make the students active and highly involved in. After applying the developed teaching-learning model to Engineering Mathematics class for one semester, we conducted survey of the participants' responses. In conclusion, we found that this model is very helpful for Engineering students to utilize a self-directed learning by diagnosing and adjusting their learning process in Meta-cognitive way. Also, it is confirmed that this model has a considerable influence in which students can actively participate in class and have positive attitude to Mathematics learning.

• Journal of the Korean Society of Industry Convergence
• /
• v.21 no.5
• /
• pp.197-205
• /
• 2018

In this research, tricycle vehicle simulation based on multi-body environment has been introduced. Mathematical model of tricycle vehicle was developed. In this research the left and right wheel speed are calculated based on the rear steering angle and velocity. The kinematic model for the three - wheel drive system was completed and the results were analyzed using the actual vehicle drawings. Through simulink vehicle performance on linear and rotation movement were simulated. Using the mathematical model the control system can be applied directly to the tricycle vehicle. The simulation result shows that the proposed vehicle model is successfully represent the movement characteristics of the real vehicle. This model assists the vehicle developer to create the controller and understand the vehicle during the development process.

• Environmental and Resource Economics Review
• /
• v.13 no.4
• /
• pp.735-761
• /
• 2004

As a possible alternative to Traditional Discounted Cash Flow Method, "Option Pricing Model" has drawn academic attentions for the last a few decades. However, it has failed to replace traditional DCF method practically due to its mathematical complexity. This paper introduces an option pricing valuation model specifically adjusted for the natural resource development projects. We add market information and industry-specific features into the model so that the model remains objective as well as realistic after the adjustment. The following two features of natural resource development projects take central parts in model construction; product price is a unique source of cash flow's uncertainty, and the projects have cost structure from capital-intense industry, in which initial capital cost takes most part of total cost during the projects. To improve the adaptability of Option Pricing Model specifically to the natural resource development projects, we use Two-Factor Model and Long-term Asset Model for the analysis. Although the model introduced in this paper is still simple and reflects limited reality, we expect an improvement in applicability of option pricing method for the evaluation of natural resource development projects can be made through the process taken in this paper.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.20 no.3
• /
• pp.63-70
• /
• 2016

The pyrotechnic separation devices are widely used in space systems and guided weapons during the launching and operations, however, they generate intensive pyroshock and fragments that can cause critical damages or the malfunction of electric devices onboard. There have been proposed many types of alternative devices to avoid pyro-induced problems since 1960's. A ball-type separation bolt is the one of alternative Pyrotechnic Mechanical Devices (PMD). In this study, the detail separation behavior of the ball-type separation bolt is analyzed using ANSYS AUTODYN. A simplified one-dimensional mathematical model, consisting of a combustion model and 5-stages of differential equation of motions, is also established to effectively describe the entire separation process.

• Journal of Educational Research in Mathematics
• /
• v.8 no.2
• /
• pp.453-474
• /
• 1998

This study is focused on the possibility if we can use graphic calculators in teaching and learning school mathematics. This study is consisted with four main chapters. In chapter II, the functions of the graphic calculator EL-9600 produced by Sharp Corporation was analyzed focused on the possibilities if the functions could be used in teaching and learning school mathematics. Calculating of real numbers and complex numbers, solving equations and system of linear equations, calculating of matrices, graphing of several functions including polynomial functions, trigonometric functions, exponential and logarithmic functions, calculation of differential and integrals, arranging of statical data, graphing of statistical data, testing of statistical hypotheses, and other more useful functions were founded. In Chapter III, a mathematics textbook developed by Core-Plus Mathematics Project was analyzed focused on how a graphic calculator was used in teaching and learning mathematics, In the textbook, graphic calculator was used as a tool in understanding mathematical concepts and solving problems. Graphic calculator is not just a tool to do complex computations but a tool used in the processes of doing mathematics, In chapter IV, the 7th mathematics curriculum for korean secondary schools was analyzed to find the contents could be taught by using graphic calculators. Most of the domains, except geometric figure, were found that they could be taught by using graphic calculators, In chapter V, a model of a unit using graphic calculator in teaching 7th mathematics curriculum was developed. In this model, graphic calculator was used as a tool in the processes of understanding mathematical concepts and solving problems. This study suggests the possibilities that we can use graphic calculators effectively in teaching and learning mathematical concepts and problem solving for most domains of secondary school mathematics.

• Journal of the Korea Computer Graphics Society
• /
• v.21 no.5
• /
• pp.1-10
• /
• 2015

This study proposes a method of developing authoring tool that can easily and intuitively generate diverse digital leaves that compose virtual landscape. The main system of the proposed authoring tool consists of deformation method for the contour of leaf blade based on image warping, procedural modeling of leaf vein and visualization method based on mathematical model that expresses the color and brightness of leaves. First, the proposed authoring tool receives leaf input image and searches for contour information on the leaf blades. It then designs leaf blade deformation method that can generate diverse shapes of leaf blades in an intuitive structure using feature-based image warping. Based on the computed leaf blade contour, the system implements the generalized procedural modeling method suitable for the authoring tool that generates natural vein patterns appropriate for the leaf blade shape. Finally, the system applies visualization function that can express color and brightness of leaves and their changes over time using a mathematical model based on convolution sums of divisor functions. This paper provides texture support function so that the digital leaves that were generated using the proposed authoring tool can be used in a variety of three-dimensional digital contents field.

• Journal of the Korea Society of Computer and Information
• /
• v.21 no.8
• /
• pp.57-64
• /
• 2016

Initial prevention activities and rapid propagation conditions is the most important to prevent diffusion of water pollution. If water pollutants flow into streams river or main stresm located in environmental conservation area or water intake facilities, we must predict immediately arrival time and the diffusion concentration to the proactive. National Institute of Environmental Research developed water pollution incident response prediction system linking dam and movable weir. the system is mathematical model which is updated daily. Therefore it can quickly predict the arrival time and the diffusion concentration when there are accident of oil spills and hazardous chemicals. Also we equipped with mathematical model and toxicity model of EFDC(Environmental Fluid Dynamics Code) to calculate the arrival time and the diffusion concentration. However these systems offer the services of an offline manner than real-time control services. we have ensured the reliability of data collection and have developed a real-time water quality measurement data transmission device by using the data linkage utilizing a mode bus communication and a commercial SCADA system, in particular, we implemented to be able to do real-time water quality prediction through information infrastructure of the water quality integrated management business created by utilizing the construction of the real-time prediction system that utilizes the data collected, the Open map, the visual representation using charts API and development of integrated management system development based on web maps.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.17 no.7
• /
• pp.875-880
• /
• 2007

Scientific challenges in the field of MR(magnetorheological) fluids and devices consist in the development of MR devices, the mathematical modeling and simulation of MR devices, and the development of (optimal) control algorithm for MR device systems. To take a maximum advantage of MR fluids in control applications a reliable mathematical model, which predicts their nonlinear characteristics, is needed. A inverse model of the MR device is required to calculate current(or voltage) input of MR damper, which generates required damping force. In this paper, we implemented test a bench for shear mode rotary MR damper and laboratory tests were performed to study the characteristics of the prototype shear-mode rotary MR damper. The direct identification and inverse dynamics modeling for shear mode rotary MR dampers using multi-layer neural networks are studied.

• The Mathematical Education
• /
• v.57 no.4
• /
• pp.329-352
• /
• 2018

This study analyzed each process of demand analysis(A), design(D), development(D), implementation(I) and evaluation(E) of the program to support mathematics learning of students with under-achievement of math in high school. To analyze the demand, a survey was conducted on 235 high school math teachers and 334 high school students who were under-achieved in mathematics. To design and develope the program, this study linked middle school math to high school math so that the students with poor math learning could easily participate in mathematics learning. The programs developed in this study were implemented in three high schools, where separate classes were organized and run for students with poor math learning. The evaluation of the programs developed in this study was done in two ways. One was a quantitative evaluation conducted by five experts, and the other was a qualitative evaluation conducted through interviews with teachers and students participating in the program. This study found that students with poor mathematics learning were more motivated to learn, started to do mathematics, and encouraged to be confident when using learning materials that included easy problems and detailed solutions that they could solve themselves. From these results, the following three implications can be derived in developing a program to support students who are experiencing poor mathematics learning in high school. First, we should develop learning materials that link middle school mathematics to high school mathematics so that students can supplement middle school mathematics related to high school mathematics. Second, we need to develop learning materials that include detailed solutions to basic examples and include homogeneous problems that can be solved while looking at the basic example's solution process. Third, we should avoid the challenge of asking students who are under-achieving to respond too openly.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 1995.04a
• /
• pp.53-56
• /
• 1995

Despite the recent development of structural analysis programs for the CRCP pavements over Westergaard's equations and finite element techniques, the Winkler foundations which are modelled by series of vertical springs at the nodes are generally used for the computer modelling of subbases under the concrete slab. Herewith, two parameter of soil foundation model is adopted as the most convenient mathematical model to enable deflections outside the loaded area to be effected and to upgrade the Winkler foundations. This paper highlights the derivations of finite element method for the two-parameter soil foundation model in the concrete pavements.