• Title/Summary/Keyword: Cross-sections

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DIAGONAL LIFTS OF TENSOR FIELDS OF TYPE (1,1) ON CROSS-SECTIONS IN TENSOR BUNDLES AND ITS APPLICATIONS

  • Gezer, Aydin;Salimov, Arif
    • Journal of the Korean Mathematical Society
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    • v.45 no.2
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    • pp.367-376
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    • 2008
  • The main purpose of this paper is to investigate diagonal lift of tensor fields of type (1,1) from manifold to its tensor bundle of type (p, q) and to prove that when a manifold $M_n$ admits a $K\ddot{a}hlerian$ structure ($\varphi$,g), its tensor bundle of type (p,q) admits an complex structure.

Dynamic Wave Model for Dendritic River Network

  • Lee, Jong-Tae
    • Korean Journal of Hydrosciences
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    • v.2
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    • pp.85-98
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    • 1991
  • This paper is focused on the development of the RIVNET1 model, which is a dynamic wave model, for flood analysis in dendritic river networks with arbitrary cross-sections. This model adopted the $-point implicit RDM and utilized a relaxation algorithim in order to solve the governing equations. The double-sweep method was used to reduce the C.P.U. time to solve the matrix system of the model. This model is applied the analyze flood waves of the Ohid river in the U.S.A. and the Keum river in Korea. The results of analysis obtained from this model are compared with those of the DWOPER and observed data.

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Automatic analysis of thin-walled laminated composite sections

  • Prokic, A.;Lukic, D.;Ladjinovic, Dj.
    • Steel and Composite Structures
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    • v.16 no.3
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    • pp.233-252
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    • 2014
  • In this paper a computer program is developed for the determination of geometrical and material properties of composite thin-walled beams with arbitrary open cross-section and any arbitrary laminate stacking sequence. Theory of thin-walled composite beams is based on assumptions consistent with the Vlasov's beam theory and classical lamination theory. The program is written in Fortran 77. Some numerical examples are given, with complete information about input and output.

Relations between Resonance Structures in Photoionization Spectra in Three-Channel-Systems Studied by Multichannel Quantum Defect Theory

  • Lee, Chun-Woo
    • Bulletin of the Korean Chemical Society
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    • v.33 no.7
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    • pp.2168-2176
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    • 2012
  • Relations between fitted parameters for photoionization spectra both below and above the thresholds in the systems involving 3 channels are obtained using phase-shifted version of the multichannel quantum-defect theory. Analytical continuation of the photoionization cross sections in the form of ${\langle}{\sigma}_{below}{\rangle}_{v_{below}}={\sigma}_{above}$ examined using several representations.

Iductance Computations of Air-Core Solenoid Magnets by FEM (유한요소법을 이용한 공심 원통현자석의 인덕탄스 계산에 관한 연구)

  • Kown, Young-Ahn
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.39 no.3
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    • pp.247-253
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    • 1990
  • The inductances of air-core solenoid magnets with circular cross sections depend on the geometric structure and winding number. For the calculation of the inductance of these magnets, Grover's table is normally used. This study presents a method to calculate the inductance using finite element method. The result of the computation agrees well with those found in the literature. Inductances of solenoid magnets with nonuniform winding distribution of complicated shapes can also be computed using this method.

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In-Plane Free Vibration Analysis of Curved Timoshenko Beams by the Pseudospectral Method

  • Lee, Jinhee
    • Journal of Mechanical Science and Technology
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    • v.17 no.8
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    • pp.1156-1163
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    • 2003
  • The pseudospectral method is applied to the analysis of in-plane free vibration of circularly curved Timoshenko beams. The analysis is based on the Chebyshev polynomials and the basis functions are chosen to satisfy the boundary conditions. Natural frequencies are calculated for curved beams of rectangular and circular cross sections under hinged-hinged, clamped-clamped and hinged-clamped end conditions and the results are compared with those by transfer matrix method. The present method gives good accuracy with only a limited number of collocation points.

Characteristics of Products in the Reaction 40 MeV/nucleon $^{14}N+Ag$

  • Chung, Yong-Hee;Porile, N. T.
    • Bulletin of the Korean Chemical Society
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    • v.15 no.11
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    • pp.971-975
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    • 1994
  • Cross sections and recoil properties have been measured for the fragments produced in the interaction of silver with 40 MeV/nucleon $^{14}N$ ions using off-line ${\gamma}$-ray spectroscopy. The data were used to obtain the isobaric-yield distribution, the mass yield distribution, and the fractional momentum transfer. The values of forward-to-backward ratios were measured to be very large, indicating that substantial momentum transfer occurs at this energy regime. The results are compared with other studies of the interaction of silver with intermediate-energy heavy ions.

Nonlinear torsional analysis of 3D composite beams using the extended St. Venant solution

  • Yoon, Kyungho;Kim, Do-Nyun;Lee, Phill-Seung
    • Structural Engineering and Mechanics
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    • v.62 no.1
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    • pp.33-42
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    • 2017
  • We present in this paper a finite element formulation for nonlinear torsional analysis of 3D beams with arbitrary composite cross-sections. Since the proposed formulation employs a continuum mechanics based beam element with kinematics enriched by the extended St. Venant solutions, it can precisely account higher order warping effect and its 3D couplings. We propose a numerical procedure to calculate the extended St. Venant equation and the twisting center of an arbitrary composite cross-section simultaneously. The accuracy and efficiency of the proposed formulation are thoroughly investigated through representative numerical examples.

A Longitudinal Study on the Body Form of Pregnant Women for Garment Designs (의복구성을 위한 임부체형의 종단적 연구)

  • Na, Mi-Hyang;Oh, Hee-Sun;Lee, Yeun-Soon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.18 no.5
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    • pp.628-636
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    • 1994
  • One vertical (medianus) and six horizontal (chest, bust, below bust, waist, abdomen and hip) sections of nine healthy pregnant women were examined every month by siliding gauge method during the period from 3rd to loth monthes of pregnancy. In the body changes along the passing months of pregnancy, which were observed by a follow·up measurement, there was little change on the posterior line when viewed using a vertical cross section. On the contrary, there was a great deal of increase on the anterior median line. Particularly, the degree of protrusion was great in the waist and ubilicus area due to pregnancy. At early pregnancy the distance from front to back is much shorter than side to side, however, as pregnancy progressed the front to back distance, on a horizontal cross section, is almost equal to the side to side distance.

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A 3D co-rotational beam element for steel and RC framed structures

  • Long, Xu;Tan, Kang Hai;Lee, Chi King
    • Structural Engineering and Mechanics
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    • v.48 no.5
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    • pp.587-613
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    • 2013
  • A 3-node 3D co-rotational beam element using vectorial rotational variables is employed to consider the geometric nonlinearity in 3D space. To account for shape versatility and reinforced concrete cross-sections, fibre model has been derived and conducted. Numerical integration over the cross-section is performed, considering both normal and shear stresses. In addition, the derivations associated with material nonlinearity are given in terms of elasto-plastic incremental stress-strain relationship for both steel and concrete. Steel reinforcement is treated as elasto-plastic material with Von Mises yield criterion. Compressive concrete behaviour is described by Modified Kent and Park model, while tensile stiffening effect is taken into account as well. Through several numerical examples, it is shown that the proposed 3D co-rotational beam element with fibre model can be used to simulate steel and reinforced concrete framed structures with satisfactory accuracy and efficiency.