• Steel and Composite Structures
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• 제18권3호
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• pp.603-621
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• 2015

In this study, theoretical models and design procedures of the behavior of thin-walled simply supported steel beams with an open cross section under a large torsional effect are presented. I-sections were chosen as the cross section types. Firstly, the widely used differential equations for the lateral buckling for the pure bending moment effect in a beam element were adopted for the various moment distributions along the span of the beam. This solution was obtained for both mono-symmetric and bisymmetric sections. The buckling loads were then obtained by using the energy method. When using the energy method to solve the problem, it is possible to locate the load not only on the shear center but also at several points of the section depth. Buckling loads were obtained for six different load types. Results obtained for different load and cross section types were checked with ABAQUS software and compared with several standard rules.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.236-239
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• 2002

The electron-atom collision studies has been essentially use\ulcorner for testing and developing suitable theories of the scattering and collision processes, and for providing a tool for obtaining detailed information on the structure of the target atoms and molecules and final collision products. And, the development of that has also been strongly motivated by the need for electron collision data in such fields as laser physic and development, astrophysics, plasma devices, upper atmospheric processes and radiation physics. Therefore, we explains the concept and the principle of determination of the electron collision cross sections for atoms and molecules by using the present electron swarm method.

• 한국전기전자재료학회논문지
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• 제16권5호
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• pp.435-440
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• 2003

The electron-atom collision studies have been essentially used for testing and developing suitable theories of the scattering and collision processes, and for providing a tool for obtaining detailed information on the structure of the target atoms and molecules and final collision products. And, the development of that has also been strongly motivated by the need for electron collision data in such fields as laser Physics and development, astrophysics, Plasma devices, upper atmospheric processes and radiation physics. The concept and the Principle of determination of the electron collision cross sections for atoms and molecules by using the present electron swarm method are explained.

• 전산구조공학
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• 제9권3호
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• pp.135-143
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• 1996

일정체적의 원형단면을 갖는 변단면 보-기둥의 자유진동 및 좌굴하중을 지배하는 미분방정식을 유도하고 이를 수치해석하였다. 미분방정식에는 축하중효과를 고려하였다. 원형단면의 반경변화는 포물선식을 채택하였고, 고정-고정, 고정-회전 및 회전-회전 보-기둥의 고유진동수 및 좌굴하중을 산출하였다. 수치해석의 결과로 무차원 고유진동수와 무차원 변수들 사이의 관계 및 무차원 좌굴하중과 단면비 사이의 관계를 그림에 나타내었고, 최강기둥의 단면비와 좌굴하중을 구하였다.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.198-201
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• 2001

This paper deals with the Automatic Analysis of Continuous Beams with Variable Cross-Section. Based on the principle of superpositon and the method of consistent deformations, the governing differential equation is derived for the deflection and stress resultants of such continuous beam. The effects of variable load conditions, the end constraints on the deflection and the stress resultants are analyzed. It is expected that the results obtained herein can be used practically in the structural engineering.

• 한국방사선학회논문지
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• 제5권4호
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• pp.217-221
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• 2011

$^{237}Np$ is very important material in the fission products of nuclear reactors. Resonance integral(RI) tests of this material is necessary to check between the experiments and the evaluated data. Such feedback to the evaluated data is very important to correct data and improve of codes. The RI for the $^{237}Np(n,{\gamma})^{238}Np$ reaction were measured by using the 46-MeV electron linear accelerator (linac) at the Research Reactor Institute, Kyoto University (KURRI). The measurement was performed in the energy region from 0.005 eV and 10 keV. RI obtained as 804.7 barns, compared with those of the evaluated data in JENDL-4.0 and Mughabghab.

• 한국농공학회지
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• 제34권4호
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• pp.97-105
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• 1992

The main purpose of this paper is to present the buckling loads of tapered columns due to dynamic concept. The ordinary differential equation governing the bucking loads for tapered columns is derived on the basis of dynamic concept. Three kinds of cross sectional shape are considered in the governing equation. The Improved Euler method and Determinant Search method are used to perform the integration of the differential equation and to determine the buckling loads, respectively. The hinged-hinged, hinged-clamped, clamped-clamped and free-clamped end constraints are applied in numerical examples. The buckling loads are reported as the function of section ratio, and the effects of cross-sectional shapes are investigated. The buckling load equation, which are fitted by numerical data, are proposed as a function of section ratio. It is expected that these equations can be utilized in structural engineering field.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(I)
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• pp.78-81
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• 1987

The scattering characteristics are analysed for the dielectric cylinder with arbitrary cross section partially covered by thin conductors. The integro differential equations consistant with boundary conditions of conductor and dielectric boundaries are derived by the equivalence principle. They are transformed into matrix equations by moment method. The circular dielectric cylinder covered by conductors at the upper and bottom side of the cylinder is chosen for the numerical example. Current distributions on conductors and scattering cross section by the cylinder are computed for incident wave perpendicular to the conductor plane.

• 대한원격탐사학회지
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• 제39권5_1호
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• pp.551-561
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• 2023

본 연구에서는 Pandora spectrometer system의 태양 직달광 관측 자료로부터 차등흡수분광법(differential optical absorption spectroscopy, DOAS)을 이용하여 포름알데히드(formaldehyde)의 경사칼럼농도(slant column density, SCD)를 산출할 때 스펙트럼 피팅(spectrum fitting) 파장 구간 및 흡수단면적이 산출에 미치는 영향을 조사하였다. 2022년 10월 12일에서 31일까지 서울 연세대학교에서 관측한 Pandora Level 1 자료를 사용하였다. The second Cabauw Intercomparison campaign for Nitrogen Dioxide measuring Instruments (CINDI-2)에서 사용하는 스펙트럼 피팅 파장 구간을 포함한 8가지 범위 및 흡수단면적 구성 7종을 기반으로 포름알데히드 칼럼농도를 산출하였다. 스펙트럼 피팅 파장 구간은 8가지 범위 중 336.5-359.0 nm 구간에서 피팅 후 잔여 신호와 포름알데히드 산출 오차가 최소로 확인되었다. 흡수단면적 구성 7종 중 CINDI-2 캠페인에서 사용하는 흡수단면적에 이산화질소 흡수단면적(220 K)을 추가하여 사용한 경우에 피팅 후 잔여 신호와 포름알데히드 산출 오차가 가장 작았으며 포름알데히드 농도가 안정적으로 산출되었다. 산출 정확도가 가장 높은 경우의 평균 포름알데히드 경사칼럼농도와 그 외 조건들에서 산출된 값들은 최소 4%에서 최대 40%까지 차이를 보였다.

• 한국산학기술학회논문지
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• 제14권10호
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• pp.4706-4712
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• 2013

편미분방정식해법을 위한 효일적인 방법 중의 하나는 미분구적법이다. 이방법은 복잡한 구조 및 하중에 따른 컴퓨터 용량의 과도한 사용뿐만 아니라, 복합알고리즘의 어려움 피하기 위해 많은 분야에 적용되어 왔다. 본 연구에서는 내평면 등분포하중 하에서 단면적이 변하는 비대칭 곡선보의 좌굴 (buckling)을 미분구적법(DQM)으로 해석하였다. 다양한 단면적 변화와 열림각 (opening angle)에 따른 임계하중을 계산하였다. DQM의 해석결과는 정확한 수학적해법 (exact analytic solution)과 비교하였으며, DQM은 적은 격자점 (grid point)을 사용하여 정확한 해석결과를 보여주었다. 또한, 다양한 단면적 변화에 따른 새로운 결과를 제시하였다.