• Journal of Korean Society of Steel Construction
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• v.13 no.1
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• pp.61-69
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• 2001

The specially orthotropic plate theory is used for analysis of panels made of girders and cross-beams. The cross-sections of both girders and cross-beams ar H-type. A method of calculating natural frequencies corresponding to the modes of vibration of beams and tower structures with irregular cross sections and arbitrary boundary conditions was developed. The results of application of this method to steel bridge by using specially orthotropic plate theory is presented. The result is compared with that of the beam theory. Finite difference method is used for this purpose. The influence of the $D_{22}$ stiffiness on the natural frequency is rigorously investigated. According to numerical examination given in this paper the result by the plate theory is 2.43 times stiffer than of beam theory.

• Journal of Korean Association for Spatial Structures
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• v.1 no.1 s.1
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• pp.143-155
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• 2001

Generally, truss design has been determined by the designer's experience and intuition. But if we perform the most economical structural design we must consider not only cross-sections of members but also configurations(howe, warren and pratt types etc.) of single truss as the number of panel and truss height. The purpose of this study is to develope automated optimum design techniques for steel truss structures considering cross-sections of members and shape of trusses simultaneously. As the results, it could be possible to find easily the optimum solutions subject to design conditions at the preliminary structural design stage of the steel truss structures. In this study, the objective function is expressed as the whole member weight of trusses, and the applied constraints are as stresses, slenderness ratio, local buckling, deflection, member cross-sectional dimensions and truss height etc. The automated optimum design algorithm of this study is divided into three-level procedures. The first level on member cross-sectional optimization is performed by the sequential unconstrained minimization technique(SUMT) using dynamic programming method. And the second level about truss height optimization is applied for obtaining the optimum truss height by three-equal interval search method. The last level of optimization is applied for obtaining the optimum panel number of truss by integer programming method. The algorithm of multi-level optimization programming technique proposed in this study is more helpful for the economical design of plane trusses as well as space trusses.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1483_1484
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• 2009

The electron collision cross sections for gases have been determined by electron beam and electron swarm method. Especially, measurements by electron swarm method is carried out by using the double shutter drift tube given by T.O.F. and Double shutter method.

• Proceedings of the Korean Nuclear Society Conference
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• 2001.05a
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• pp.75-75
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• 2001

• Proceedings of the Korean Nuclear Society Conference
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• 2001.05a
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• pp.76-76
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• 2001

• Proceedings of the Korean Nuclear Society Conference
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• 2001.05a
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• pp.492-492
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• 2001

• Proceedings of the Optical Society of Korea Conference
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• 2005.02a
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• pp.114-115
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• 2005

• Proceedings of the Korean Society of Medical Physics Conference
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• 1999.11a
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• pp.95-96
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• 1999

• Electrical & Electronic Materials
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• v.8 no.6
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• pp.806-810
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• 1995

Electron swarm studies to derive electron collision cross sections of atoms and molecules from measurements of electron swarm data are reviewed. Stress is placed on those using molecular gas-rare gas mixtures.

• Proceedings of the Korean Nuclear Society Conference
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• 1999.10a
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• pp.69.1-69
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• 1999