• Journal of the Korean School Mathematics Society
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• v.5 no.1
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• pp.13-19
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• 2002

In this experiment we emphasized the cooperative small group learning and the members of my group worked together to succeed and communicate their mathematics ideas freely. The researcher(teacher) became an observer and facilitator of small group interaction, paying attention to the ongoing learning process, Sometimes the researcher suggested some investigation approach(or discovery)being written by computer software or papers. In this experiment we provided 6 activities as follows : (1) changing the conditions in given problem. (2) operating the meaningful heuristics with the problem sets. (3) creating the problem situations related to understanding (4) creating the Modeling situations. (5) creating the problem related to combinatorial thinking in real world. (6) posing some real problem from real world. we could observed several conjectures First, Attitude and chility to interpret the problem setting is highly important to pose the problem effectively. Second, Generating the understanding can be a great tool to pose the problem effectively. Third, Sometimes inquiry approach represented by software or programmed book could be some motivation to enhance the posing activities. Forth, The various posing activities relate to one concept could give the students some opportunity to be adaptable and flexible in the their approach to unfamiliar problem sets.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.10a
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• pp.638-643
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• 1993

The three dimensional finite element models for the basic deflection of linear motion guides and ball screws were developed. Form the comparison of the results calculated by the finite element method with those by the experiment, it was proved that the modeling method might be applied to real machine tool structures. Form the structural analysis of the headstock of the machine tool, it was found that the static stiffness was calculated within 6.5% error

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.519-524
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• 2008

A numerical study is conducted to investigate propulsion performance enhancement based on S225 experiment case of ISL(French-German Research Institute of Saint-Louis)'s superdetonative ram accelerator. For govern equation, multi-species Navier-Stokes equation coupled with Baldwin-Lomax turbulence modeling is used. Govern equation is discretized by Roe's FDS and integrated by LU-SGS time integration. Detailed chemical reaction about $H_2/O_2/CO_2$ for high pressure is considered. $2H_2+O_2+2.5CO_2$ mixture was used for propellant gas. For the same over-driven factor, the launching speed of computation was faster than one of S225. Another configuration and condition of S225 was applied. A flame structure is very different from S225. For strong mixture case, it shows ignition by viscous effect. Acceleration and speed increment is higher than S225 computation and experiment. By using more strong mixture, propulsion performance was enhanced.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2338-2340
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• 2001

Recently the control using internet is investigated to realize the remote control independent of place and platform. But this approach also has several problems caused by the irregular network time delay between the server and client. The experiment results using least square estimation are presented to show the effectiveness of the proposed algorithm.

• Journal of Advanced Marine Engineering and Technology
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• v.30 no.1
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• pp.134-139
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• 2006

A energy efficiency of quadruped walking robot has been studied mathematical modeling, dynamic analysis or simulation by consumption energy per period. In this paper, We used the quadruped walking robot Titan-VIII in order to carry out this experiment. The total moving length is about 2[m] , the stride length is 0.1, 0.2. 0.3, and walking period is changed by 1.0, 1.5, 2.0, 2.5 3.0[sec] Per each stride length. So consumption energy of 15 cases are measured. As a result of this experiment we obtained the best energy efficiency when stride length was 0.3[m], and Period was 1.5[sec].

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.288-291
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• 2001

Vehicle evaluation is performed on the proving ground, and durability test and dynamic test cost lots of money and time. Doing replace real vehicle experiment with similar experiment environment, it will take us much more useful advantages. Suspension simulator is required the robust and high-reliability and used widely. But it's natural of high-leveled control technique to manage to be fitted fluid system's property and complex that is for the lack of self-damping, nonlinearity, compressibility. In designing and evaluating simulator, it is important to understand the capability of kinematic and static performances. In this paper, an kinematic modeling and analysis has been presented using ADAMS to design that can reproduce longitudinal, lateral, and vertical force.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.573-578
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• 2008

Finite element analysis of impact response of a motorcycle helmet is presented in this paper. The finite element LS-DYNA3D code is used to simulate the impact response of the helmet including of plastic shell, foam liner, and magnesium headform. Since the maximum accelerations at center of gravity of the headform obtained by numerical analysis and experiment agree well, the numerical simulation is proved to be valid.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.167-174
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• 1997

In this paper, the mathematical model of the hydraulic control valve is formulated, that is, this dynamic modeling which includes the motion equations and continuity equations can analyze the dynamic characteristics of the hydraulic control valve. The control valve for the transmission has the Over Speed Protection to protect a hydraulic travel motor. Therefore, this simulation shows the over speed protection and researches the main design parameters. The results of the computer simulation were assured through the experiment. From the comparison between both results, it is shown that this simulation program is useful and effective.

• Korean Management Science Review
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• v.9 no.1
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• pp.17-30
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• 1992

This paper is organized as follows. Section 2 illustrates several applications of neural networks. Section 3 presents the theoretical aspects of the major neural network paradigms as well as the structure of the back -propagation network used in the study. Section 4 describes the experiment including data analysis, modeling, and the performance criteria followed by the detailed discussion of the experimental results. Future research avenues including advantages and limitations of neural network are presented in the last section.

• Journal of the Korean Operations Research and Management Science Society
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• v.25 no.3
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• pp.125-135
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• 2000

Many different statistical and artificial intelligent techniques have been applied to improve the predictability of credit rating. Hybrid models and systems have also been developed by effectively combining different modeling processes or combining the outcomes of individual models. In this paper, we introduced the rough set theory and developed a hybrid credit rating system that combines individual outcomes in terms of rough set theory. An experiment was conducted to compare the prediction capability of the system with those of other methods. The proposed system based on rough set method outperformed the others.