• Title/Summary/Keyword: method of ideal elements

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The Integration of Adaptive Elements into High-Rise Structures

  • Weidner, Stefanie;Steffen, Simon;Sobek, Werner
    • International Journal of High-Rise Buildings
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    • v.8 no.2
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    • pp.95-100
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    • 2019
  • Whilst most research focuses on the reduction of operative energy use in buildings, the aspect of which (and how many) materials are used is often neglected and poorly explored. However, considering the continuous growth of the global population and the limited availability of resources, it is clear that focusing on operative energy alone is too short-sighted. The tasks lying ahead for architects and engineers cannot be accomplished with conventional methods of construction. With a share of 50-60% of global resource consumption, the building industry has a decisive impact on our environment. If business as usual continues, resources will be significantly depleted in a matter of decades. Therefore, researchers of the University of Stuttgart are investigating the concept of adaptivity as a promising method for saving resources in the built environment. The term adaptivity in the context of building structures was first introduced by Werner Sobek. It describes a method where sensors, actuators and control units are implemented in systems or facades in order to oppose physical impacts in an ideal way. The applicability of this method will be verified on an experimental high-rise building at the University campus in Stuttgart. Thus, this paper describes this innovative research project and depicts the concept of adaptivity in high-rise structures. Furthermore, it gives an overview of potential actuation concepts and the interdisciplinary challenges behind them.

A Study on Comicality of Animation (애니메이션의 희극성(喜劇性) 연구)

  • Cho, Mil-Ra
    • Cartoon and Animation Studies
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    • s.12
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    • pp.103-119
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    • 2007
  • This study investigated the comical essence of animations and the comicality found in Korean animations focusing on the comical elements signifying the promotion of laughing and its meaning. In addition, it has been found from this study that the comical essence of animations was the laughing that expanded the recognition and awareness for the entity to be revived, by suggesting the following: 1) the fact that the laughing would be unexpected and it would stimulate the imagination of audience in unprecedented situations in which the method of creation would be unthinkable and thereby the laughing occurred would endow audience with thought, feeling and sense etc. that would not have been perceived so far; and 2) furthermore, the ideal world through grotesque expressions. Meanwhile, unlike the general preconception that animations would be considered one of the popular art forms with strong comical elements, it has been noted that there have been a very few Korean animations with strong comical elements. Besides, it has been confirmed that they have focused not on created and grotesque comicality, but on linguistic comicality based on the forms of characters or their movement itself, or humor and witty remarks.

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Analysis of Earthquake Responses of a Floating Offshore Structure Subjected to a Vertical Ground Motion (해저지진의 수직지반운동에 의한 부유식 해양구조물의 지진응답 해석기법 개발)

  • Lee, Jin Ho;Kim, Jae Kwan;Jin, Byeong Moo
    • Journal of the Earthquake Engineering Society of Korea
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    • v.18 no.6
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    • pp.279-289
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    • 2014
  • Considering a rigorously fluid-structure interaction, a method for an earthquake response analysis of a floating offshore structure subjected to vertical ground motion from a seaquake is developed. Mass, damping, stiffness, and hydrostatic stiffness matrices of the floating offshore structure are obtained from a finite-element model. The sea water is assumed to be a compressible, nonviscous, ideal fluid. Hydrodynamic pressure, which is applied to the structure, from the sea water is assessed using its finite elements and transmitting boundary. Considering the fluid-structure interaction, added mass and force from the hydrodynamic pressure is obtained, which will be combined with the numerical model for the structure. Hydrodynamic pressure in a free field subjected to vertical ground motion and due to harmonic vibration of a floating massless rigid circular plate are calculated and compared with analytical solutions for verification. Using the developed method, the earthquake responses of a floating offshore structure subjected to a vertical ground motion from the seaquake is obtained. It is concluded that the earthquake responses of a floating offshore structure to vertical ground motion is severely influenced by the compressibility of sea water.

Robotic Workplace Calibration Using Teaching Data of Work-Piece Fixed in Robotic Workplace for Robot Off-line Programming (로봇 오프라인 프로그래밍을 위한 작업장에 고정된 공작물 교시 정보를 이용한 로봇작업장 보정)

  • Jeong, Jun Ho;Kuk, Kum Hoan
    • Journal of the Korean Society for Precision Engineering
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    • v.30 no.6
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    • pp.615-621
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    • 2013
  • The robot calibration has greatly improved the absolute accuracy of the industrial robot. However, the accuracy of the relative positions of robotic tool-tip at work-points on a work-piece is only slightly corrected by the robot calibration since there has been no practical method to eliminate the elements of the setup position errors at a robotic workplace. A robotic workplace calibration is demonstrated in this paper to minimize the relative position errors between a robot tool-tip and the work-point on a work-piece. The existing teaching and playback method has been developed for the robotic workplace calibration. This paper uses the work-piece fixed in a robotic work-place as measurement equipment instead of a special robot measurement equipment for the robotic workplace calibration. The positive effect of the robotic workplace calibration is supported by the results of computer simulation on an ideal robotic workplace model and an experiment at the actual robotic workplace.

Structural Optimization based on Equivalent Static Load for Structure under Dynamic Load (동하중을 받는 구조물의 등가정하중 기반 구조최적화 연구)

  • Kim, Hyun Gi;Kim, Eui young;Cho, Maenghyo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2013.10a
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    • pp.236-240
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    • 2013
  • Due to difficulty of considering dynamic load in side of a computer resource and computing time, it is common that external load is assumed as ideal static load. However, structural analysis under static load cannot guarantee the safety of structural design. Recently, the systematic method to construct equivalent static load from the given dynamic load has been proposed. Previous study has calculated equivalent static load through the optimization procedure under displacement constraints. And previously reported works to distribute equivalent static load were based on ad hoc methods. However, it is appropriate to take into account the stress constraint for the safety design. Moreover, the improper selection of loading position may results in unreliable structural design. The present study proposes the methodology to optimize an equivalent static which distributed on the primary DOFs, DOFs of the constraint elements, DOF of an external load as positions. In conclusion, the reliability of proposed method is demonstrated through a global optimization.

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Hygrothermal Fracture Analysis in Dissimilar Materials

  • Ahn, Kook-Chan;Lee, Tae-Hwan;Bae, Kang-Yul
    • International Journal of Aeronautical and Space Sciences
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    • v.2 no.2
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    • pp.65-72
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    • 2001
  • This paper demonstrates an explicit-implicit, finite element analysis for linear as well as nonlinear hygrothermal stress problems. Additional features, such as moisture diffusion equation, crack element and virtual crack extension(VCE) method for evaluating J-integral are implemented in this program. The Linear Elastic Fracture Mechanics(LEFM) Theory is employed to estimate the crack driving force under the transient condition for an existing crack. Pores in materials are assumed to be saturated with moisture in the liquid form at the room temperature, which may vaporize as the temperature increases. The vaporization effects on the crack driving force are also studied. The ideal gas equation is employed to estimate the thermodynamic pressure due to vaporization at each time step after solving basic nodal values. A set of field equations governing the time dependent response of porous media are derived from balance laws based on the mixture theory. Darcy's law is assumed for the fluid flow through the porous media. Perzyna's viscoplastic model incorporating the Von-Mises yield criterion are implemented. The Green-Naghdi stress rate is used for the invariant of stress tensor under superposed rigid body motion. Isotropic elements are used for the spatial discretization and an iterative scheme based on the full Newton-Raphson method is used for solving the nonlinear governing equations.

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A Study on the book reviews published in review periodicals (문헌비평을 위한 서평의 분석적 고찰 -서평문화와 출판저널을 중심으로-)

  • 김상호
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.7 no.1
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    • pp.247-262
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    • 1994
  • This study is concerned with analysis of all the reviews published by the reviewing periodicals, The Book Review Culture and The Korean Publishing Journal, from 1991 to 1993. The result of analysis for 736 reviews are followed: 1) The percentage of reviews in the field of philosophy & religion, literature & language, science & technology is lower than the percent-age of books published. But in the field of history and social science the reviewing is proportionately higher than the publishing. 2) Book reviews are prepared by professors, literary reviewers, researchers, and experts in the particular subject field except librarian. 3) Basic elements of reviewing are the career and view point of author, trends of suject field, content, value, omissions, limitations, and format of book, reader's level, etc. Ideal method of book criticism may be summarized as follows: 1) The criterion of book selection are the book's value, the social . demand, and the proportion of titles published. 2) For the unbiased criticism, it should be written by the experienced librarian rather than the experts of particular subject field. 3) Book criticism need to provide not only guide to new books but also interpretation and evaluation about each book for its reader.

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Equivalent Network Modeling of Slot-Coupled Microstripline to Waveguide Transition (슬롯 결합 마이크로스트립라인-도파관 천이기의 등가 회로 모델링)

  • Kim Won-Ho;Shin Jong-Woo;Kim Jeong-Phill
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.15 no.10 s.89
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    • pp.1005-1010
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    • 2004
  • An analysis method of slot-coupled microstripline to waveguide transition is presented to developed a simple but accurate equivalent circuit model. The equivalent circuit consists of an ideal transformer, microstrip open stub, and admittance elements looking into a waveguide and a half space of feed side from a slot center. The related circuit element values are calculated by applying the reciprocity theorem, the Fourier transform and series representation, the complex power concept, and the spectral-domain immittance approach. The computed scattering parameters are compared with the measured, and good agreement validates the simplicity and accuracy of the proposed equivalent circuit model.

Numerical Analysis of Two-Dimensional Nonlinear Radiation Problem Using Higher-Order Boundary Element Method (고차경계요소법을 이용한 2차원 비선형 방사문제의 수치해석)

  • Hong-G. Sung;Hang-S. Choi
    • Journal of the Society of Naval Architects of Korea
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    • v.37 no.1
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    • pp.67-81
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    • 2000
  • An accurate and efficient numerical method for two-dimensional nonlinear radiation problem has been developed. The wave motion due to a moving body is described by the assumption of ideal fluid flow, and the governing Laplace equation can be effectively solved by the higher-order boundary element method with the help of the GMRES (Generalized Minimal RESidual) algorithm. The intersection or corner problem is resolved by utilizing the so-called discontinuous elements. The implicit trapezoidal rule is used in updating solutions at new time steps by considering stability and accuracy. Traveling waves caused by the oscillating body are absorbed downstream by the damping zone technique. It is demonstrated that the present method for time marching and radiation condition works efficiently for nonlinear radiation problem. To avoid the numerical instability enhanced by the local gathering of grid points, the regriding technique is employed so that all the grids on the free surface may be distributed with an equal distance. This makes it possible to reduce time interval and improve numerical stability. Special attention is paid to the local flow around the body during time integration. The nonlinear radiation force is calculated by the "acceleration potential technique". Present results show good agreement with other numerical computations and experiments.

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The Flow Analysis of Jeju Harbor using Moving Boundary Technique (이동경계기법을 이용한 제주항의 유동해석)

  • Kim, Nam-Hyeong;Park, Ji-Hun
    • Journal of Navigation and Port Research
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    • v.27 no.5
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    • pp.539-546
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    • 2003
  • The numerical model of the flow analysis by finite element technique is described. The Galerkin method is employed for spatial discretization Two step explicit finite element scheme is used to discretize the time function, which has advantage in problems treating large numbers of elements and unsteady state. Two dimensional hydrodynamic model considering moving boundary condition is developed. Also it applied flow model which develop on flow portion of ideal fluid in the model flume and verified, and the results of this study confirm the efficiency of moving boundary treatment in Jeju harbor. The computed results have shown the good adaptability of moving boundary condition From these studies, it can be concluded that the present method is a useful and effective tool in tidal flow analysis.