• Journal of the Korean School Mathematics Society
• /
• v.14 no.1
• /
• pp.101-122
• /
• 2011

In this paper, we investigated teachers' awareness for the gifted education using technology. We chose teachers who were taking a course(60 hours) in the gifted education at Educational Training Institute in Chonnam National University, and analyzed their awareness for gifted education using technology. We found teachers' awareness as followings. First, teachers think that their ability using technology is contained ability developing and performing program for the gifted education. Second, using technology in the gifted education have an effect on ability of inventively solving problem and extension of thinking power of the gifted. Third, the gifted education using technology is helpful to developing abilities of the gifted, which are intuitional discernment, organizing information, space perception and visualization. Also, that is helpful to developing fluency, flexibility and uniqueness of the gifted in terms of sub-factors of creativity (fluency, flexibility, uniqueness, sophistication).

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.36 no.8
• /
• pp.873-879
• /
• 2012

Metamodels have been developed with a variety of design optimization techniques in the field of structural engineering over the last decade because they are efficient, show excellent prediction performance, and provide easy interconnections into design frameworks. To construct a metamodel, a sequential procedure involving steps such as the design of experiments, metamodeling techniques, and validation techniques is performed. Because validation techniques can measure the accuracy of the metamodel, the number of presampled points for an accurate kriging metamodel is decided by the validation technique in the sequential kriging metamodel. Because the interpolation model such as the kriging metamodel based on computer experiments passes through responses at presampled points, additional analyses or reconstructions of the metamodels are required to measure the accuracy of the metamodel if existing validation techniques are applied. In this study, we suggest a sensitivity validation that does not require additional analyses or reconstructions of the metamodels. Fourteen two-dimensional mathematical problems and an engineering problem are illustrated to show the feasibility of the suggested method.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.37 no.9
• /
• pp.1133-1140
• /
• 2013

A computer model is a useful tool that provides solution via physical modeling instead of expensive testing. In reality, however, it often does not agree with the experimental data owing to simplifying assumption and unknown or uncertain input parameters. In this study, a Bayesian approach is proposed to calibrate the computer model in a probabilistic manner using the measured data. The elasto-plastic analysis of a pyrotechnically actuated device (PAD) is employed to demonstrate this approach, which is a component that delivers high power in remote environments by the combustion of a self-contained energy source. A simple mathematical model that quickly evaluates the performance is developed. Unknown input parameters are calibrated conditional on the experimental data using the Markov Chain Monte Carlo algorithm, which is a modern computational statistics method. Finally, the results are applied to determine the reliability of the PAD.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.24 no.3
• /
• pp.245-250
• /
• 2014

Addiction can be largely divided into two categories. One is called medium addiction in which medium itself causes an addiction. Another is called cause addiction that brings addiction through combination of sensitive self and latent personal action. The medium addiction involves addiction phenomena directly caused by illegal drugs, alcohol and various other chemicals. The cause addiction is dependent on personal sensitivities as a sensitive problem of personal and includes cyber addictions such as shopping, work, game, internet, TV, and gambling. In this paper we propose two-dimensional addiction model that are equivalent to using an R-L-C series circuit of Electrical circuit and a Spring-Damper-mass of mechanical system. We also organize a Duffing equation that is added a nonlinear term in the proposed two-dimensional addiction model. We represent periodic motion and chaotic motion as time series and phase portrait according to parameter's variation. We confirm that among parameters chaotic motion had addicted state and periodic motion caused by change in control coefficient had pre-addiction state.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.23 no.5
• /
• pp.479-486
• /
• 2013

There exist two major difficulties in developing flight control system: nonlinear dynamic characteristics and time-varying properties of parameters of aircraft. Instead of the difficulties, many high reliable and efficient control methodologies have been developed. But, most of the developed control systems are based on the exact mathematical modelling of aircraft and, in the absence of such a model, it is very difficult to derive performance, robustness and nominal stability. From these aspects, recently, some approaches to utilizing the intelligent control theories such as fuzzy logic control, neural network and genetic algorithm have appeared. In this paper, one advanced intelligent lateral control system of a high speed fight has been developed utilizing type-2 fuzzy logic, which can deduce the uncertainty problem of the conventional fuzzy logic. The results will be verified through computer simulation.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.17 no.1
• /
• pp.1-10
• /
• 1992

In the already presented paper, the performance analysis of SMUX was need a lot of time bacause of recussive method, So this paper proposed the new mathematical method for the SMUX's performance. And it is constructed and analyzed the queueing model for SMUX based on the Go-back N retransmission ARQ model. It is assumed that it has the infinite buffer and a single server. It is analzied the parameters that have influence on the byffer and a single server. It is analzied the parameters that have influence on the buffer behaviour of statistical multiplexer overflow probabilities. maximum buffer size. mean wating time and mean buffer size, and these relationship are represented the graphs and datas which provided a guide to the buffer design problem. As these results. it is efficient when the SMUX is apphed that the traffic density is below 0.5 and transmission error probabilities is below 10­$^3$. So this paper can be applied to the basic and theoretical background prior to the implementation of SMUX.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.31 no.3
• /
• pp.58-64
• /
• 2003

Pogo is the instability resulting from the interaction between rocket structure and propulsion system of liquid propellant rocket. The coupling of structure and propulsion system can lead to severe problem in rocket. For the analysis of pogo, a time-invariant linearized mathematical model is developed for a selected flight time. Propulsion system is modeled using element representations for each components. Rocket structure is modeled using FEM. Form the results of modal analysis of structure, the behavior of structure can be represented. System equations for coupling structure and propulsion system are composed. The stability in obtained by the eigen solution of system matrix. The optimization of the design variables such as size, place of accumulator for suppressing pogo instability in carried out. This article of study can be used to determine the degree of stability, and guide the design of pogo suppression system.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.38 no.5
• /
• pp.575-584
• /
• 2014

In this study, the NREL 5 MW wind turbine tower model was optimized according to the multi-body dynamics and reliability-based design. The mathematical model was defined as a link-joint system including dynamic characteristics derived from Timoshenko's beam theory. For the optimization problem, the sensitivities to variations in the tower thicknesses and inner and outer diameters were acquired and arranged in terms of safety and efficiency according to bending stress and buckling standards. An optimal design was calculated with the advanced first-order second moment method and used to define a finite element model for validation. The finite element model was simulated by static analysis. The relationship between the multi-body dynamic and finite element method throughout the process was investigated, and the optimal model, which had high endurance despite its low mass, was determined.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.38 no.5
• /
• pp.489-495
• /
• 2014

A micro-genetic algorithm (MGA) is one of the improved forms of a genetic algorithm. It is used to reduce the number of iterations and the computing resources required by using small populations. The efficiency of MGAs has been proved through many problems, especially problems with 3-5 design variables. This study proposes an optimization algorithm based on the sequential design of experiments (SDOE) and an MGA. In a previous study, the authors used the SDOE technique to reduce trial-and-error in the conventional approximate optimization method by using the statistical design of experiments (DOE) and response surface method (RSM) systematically. The proposed algorithm has been applied to various mathematical examples and a structural problem.

• Journal for History of Mathematics
• /
• v.19 no.4
• /
• pp.63-80
• /
• 2006

Along with natural and algebraic languages, schema is a fundamental component of mathematical language. The principal purpose of this present study is to focus on this point in detail. Schema was already in use during Pythagoras' lifetime for making geometrical inferences. It was no different in the case of Oriental mathematics, where traces have been found from time to time in ancient Chinese documents. In schma an idea is transformed into something conceptual through the use of perceptive images. It's heuristic value lies in that it facilitates problem solution by appealing directly to intuition. Furthermore, introducing schema is very effective from an educational point of view. However we should keep in mind that proof is not replaceable by it. In this study, various schemata will be presented from a diachronic point of view, We will show with emaples from the theory of categories, Feynman's diagram, and argand's plane, that schema is an indispensable tool for constructing new knowledge.