• 제목/요약/키워드: Structure of Elements

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Stresses analyses of shell structure with large holes

  • Tian, Zongshu;Liu, Jinsong
    • Structural Engineering and Mechanics
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    • v.6 no.8
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    • pp.883-899
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    • 1998
  • The strength, deformation and buckling of a large engineering structure consisting of four ellipsoidal shells, two cylindrical shells with stiffening ribs and large holes, one conical shell and three pairs of large flanges under external pressure, self weight and heat sinks have been analysed by using two kinds of five different finite elements - four assumed displacement finite elements (shell element with curved surfaces, axisymmetric conical shell element with variable thickness, three dimensional eccentric beam element, axisymmetric solid revolutionary element) and an assumed stress hybrid element (a 3-dimensional special element developed by authors). The compatibility between different elements is enforced. The strength analyses of the top cover and the main vessel are described in the paper.

KPACK: Relativistic Two-component Ab Initio Electronic Structure Program Package

  • Kim, Inkoo;Lee, Yoon Sup
    • Bulletin of the Korean Chemical Society
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    • v.34 no.1
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    • pp.179-187
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    • 2013
  • We describe newly developed software named KPACK for relativistic electronic structure computation of molecules containing heavy elements that enables the two-component ab initio calculations in Kramers restricted and unrestricted formalisms in the framework of the relativistic effective core potential (RECP). The spin-orbit coupling as relativistic effect enters into the calculation at the Hartree-Fock (HF) stage and hence, is treated in a variational manner to generate two-component molecular spinors as one-electron wavefunctions for use in the correlated methods. As correlated methods, KPACK currently provides the two-component second-order M${\o}$ller-Plesset perturbation theory (MP2), configuration interaction (CI) and complete-active-space self-consistent field (CASSCF) methods. Test calculations were performed for the ground states of group-14 elements, for which the spin-orbit coupling greatly influences the determination of term symbols. A categorization of three procedures is suggested for the two-component methods on the basis of spin-orbit coupling manifested in the HF level.

A Study on the Design Elements for Steel-Framed School Buildings (철골조학교(鐵骨組學校)의 설계요소(設計要素)에 관한 연구(硏究))

  • Lee, Jae-Hoon;Hwang, Jun-Geun
    • Journal of the Korean Institute of Educational Facilities
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    • v.11 no.1
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    • pp.47-57
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    • 2004
  • The Architects' design process is subjective and mysterious'. If we can reveal this process, it will be very helpful to proceed similar design projects. In the aspect of steel production, Korea is a strong country, but in the aspect of steel usage, Korea does not show its impacts as compared with other countries'. Even though steel has many merits in design as well as in structure, in Korea we have not applied it as design elements. In this situation, the demand of steel in school buildings is increasing, but steel also is used only on the basis of the structural and material meaning. So this thesis tries to find design elements of steel structure buildings, which can be applied in school buildings, through the analysis of existing steel structure buildings and the characteristics of steel.

Seismic Analysis of Rectangular Liquid Storage Structures Ssing Fluid Elements (유체요소를 이용한 직사각형 유체 저장구조물의 지진해석)

  • 김영석;김제민;윤정방
    • Journal of Ocean Engineering and Technology
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    • v.6 no.2
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    • pp.46-54
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    • 1992
  • In this paper, behavior of rectangular storage structures under earthquake loadings are investigated. Linear sloshing is assumed in this study. The effect of the wall flexibility is considered. Eulerian and lagrangian approaches are presented. The Eulerian approach is carried out by solving the boundary value problem for the fluid motion. In the lagrangian approach, the fluid as well as the storage structure is modelled by the finite element method. The fluid region is discretized by using fluid elements. The (1 $\times$ 1)-reduced integration is carried out for constructing the stiffness matrices of the fluid elements. Seismic analysis of the coupled system is carried out by the response spectra method. The numerical results show that the fluid forces on the wall obtained by two approaches are in good agreements. By including the effect of the wall flexibility, the forces due to fluid motion can be increased very significantly.

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Modeling and Vibration Analysis of Vehicle Structures Using Equivalent Beam Stiffness for Joints (결합부 등가빔을 이용한 저진동 차체의 모델링 및 해석기법)

  • 임홍재;김윤영;이상범;송명의
    • Journal of KSNVE
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    • v.5 no.4
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    • pp.537-542
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    • 1995
  • In this paper the method of modeling and optimization for the joint of the vehicle structure is proposed. First it is described that the method of substituting equivalent beam elements to spring elements for the joint. The stiffnesses of the spring elementsare calculated using the section properties of equivalent beam elements. To get required dynamic characteristics section properties of equivalent beam element are set to design variables and optimized. The study shows that joint stiffnesses can be effectively determined in designing vehicle structure.

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An analysis on the structure of the Romanesque era's costume - Centering around woman's costume - (로마네스크 시대 복식의 구조적 분석 - 여성복식을 중심으로 -)

  • 윤점순
    • Korean Journal of Human Ecology
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    • v.1 no.1
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    • pp.113-125
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    • 1998
  • This study has resulted in the followings applying costume's form and meaning to the theory of structuralism established by Saussure and the extensive and contained meanings of Roland Barthes. The kinds of woman's costume of the Romanesque era were not various, but those of the royal family and aristocratic class were more various and decorated better than the lowly persons. So their social levels could be differed by the forms of the costume they wore. Each form of costume was differed according to the structural elements and showed the feature that the form is the costume of the era and social position's differences of the wearers' sexes, levels, and vocations in the same era. Costume's analistic body was the costume's form selected according to the central analystic elements, this showed the meaning of the era's levels and classes, that is, the costume's structure was reflected by the era's features. In the structure of the woman's costume in the Romanesque era, many religious features were emphasized and the elements forming each analystic body were classified and meant the society's features. (Korean J Human Ecology l(1) : 113∼125, 1998)

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Soil-Structure Interaction Analysis in the Time Domain Using Explicit Frequency-Dependent Two Dimensional Infinite Elements (명시적 주파수종속 2차원 무한요소를 사용한 지반-구조물 상호작용의 시간영역해석)

  • 윤정방;김두기
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1997.10a
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    • pp.42-49
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    • 1997
  • In this paper, the method for soil-structure interaction analyses in the time domain is proposed. The far field soil region which is the outside of the artificial boundary is modeled by using explicit frequency-dependent two dimensional infinite elements which can include multiple wave components propagating into the unbounded medium. Since the dynamic stiffness matrix of the far field soil region using the proposed infinite elements is obtained explicitly in terms of exciting frequencies and constants in the frequency domain, the matrix can be easily transformed into the displacement unit-impulse response matrix, which corresponds to a convolution integral of it in the time domain. To verify the proposed method for soil-structure interaction analyses in the time domain, the displacement responses due to an impulse load on the surface of a soil layer with the rigid bed rock are compared with those obtained by the method in the frequency domain and those by models with extend finite element meshes. Good agreements have been found between them.

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STRUCTURE OF UNIT-IFP RINGS

  • Lee, Yang
    • Journal of the Korean Mathematical Society
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    • v.55 no.5
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    • pp.1257-1268
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    • 2018
  • In this article we first investigate a sort of unit-IFP ring by which Antoine provides very useful information to ring theory in relation with the structure of coefficients of zero-dividing polynomials. Here we are concerned with the whole shape of units and nilpotent elements in such rings. Next we study the properties of unit-IFP rings through group actions of units on nonzero nilpotent elements. We prove that if R is a unit-IFP ring such that there are finite number of orbits under the left (resp., right) action of units on nonzero nilpotent elements, then R satisfies the descending chain condition for nil left (resp., right) ideals of R and the upper nilradical of R is nilpotent.

A Study on the Spatial Composition of Hyangdan (향단(香壇)의 건축공간(建築空間) 구성수법(構成手法) 연구(硏究))

  • Ro, Dong-Sung;Hong, Dae-Hyung
    • Journal of architectural history
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    • v.8 no.3 s.20
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    • pp.39-51
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    • 1999
  • The purpose of this study is to establish the theory of the spatial composition that is 'The Structure of Relation' in Korean traditional houses. This study has been focused on the spatial composition of Hyangdan. The form composition is an element defining primitive functions and space and producing aesthetical effects, where 'quality as a substance' is not important but 'quality as a relation' is essential. Quality as a meaningful relationship comes from realization and regulation of visual attributes among form elements. Each form compositional element establishes the hierarchical structure logically with the entire order, In order for the quality of all form compositional elements to be clarified as a meaningful relationship logically, 'compositional concept' which combines a series of form elements into the grammatical dependence to a specific direction, has to be assumed. If the intrinsic relationship among a series of form compositional elements fails to confront with the 'contextual concept' which eventually indicates unique conditions for a place according to the refined compositional concept, the result of form composition never leads to a specific solution

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An Analysis of Mechanical Features and Variations of Design Composition Elements for Pratt Trusses (프랫트러스의 디자인 구성요소 변화와 역학적 특성분석)

  • Park, Chan-Soo;Lee, Ju-Na
    • Journal of Korean Association for Spatial Structures
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    • v.13 no.2
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    • pp.47-55
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    • 2013
  • The design composition elements and the mechanical behavior of trusses have been investigated for Pratt trusses. As a result, it was determined that the design composition elements of the trusses consist of the composition of webs, the distance between joints, the chords profile, the depth of the truss, and the double chord composition. In addition, by analyzing models with a variation of elements, comprehensive features of structural behavior have been presented for variations of design of Pratt trusses. This is to provide more effective and useful design information on truss structure in the architectural and structural planning stage.