• 제목/요약/키워드: space structures

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확장 칼만 필터 이론을 이용한 3차원 트러스 구조물의 2단계 손상 추정법 (2-Step Damage Assessment of 3-D Truss Structures Using Extended Kalman Filter Theory)

  • 유숙경;서일교;권택진
    • 한국공간구조학회논문집
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    • 제2권1호
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    • pp.41-49
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    • 2002
  • In this paper, a study of 2-step damage detection for space truss structures using the extended Kalman filter theory is presented. Space truss structures are composed of many members, so it is difficult to find damaged member from the whole system. Therefore, 2-step damage identification method is applied to detect the damaged members. First, kinetic energy change ratio is used to find damage region including damaged member and then detect damaged member using extended Kalman filtering algorithm in damage region. The effectiveness of proposed method is verified through the numerical examples.

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The Application of Piezoelectric Materials in Smart Structures in China

  • Qiu, Jinhao;Ji, Hongli
    • International Journal of Aeronautical and Space Sciences
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    • 제11권4호
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    • pp.266-284
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    • 2010
  • Piezoelectric materials have become the most attractive functional materials for sensors and actuators in smart structures because they can directly convert mechanical energy to electrical energy and vise versa. They have excellent electromechanical coupling characteristics and excellent frequency response. In this article, the research activities and achievements on the applications of piezoelectric materials in smart structures in China, including vibration control, noise control, energy harvesting, structural health monitoring, and hysteresis control, are introduced. Special attention is given to the introduction of semi-active vibration suppression based on a synchronized switching technique and piezoelectric fibers with metal cores for health monitoring. Such mechanisms are relatively new and possess great potential for future applications in aerospace engineering.

지하철정거장 화재에 대한 강구조물의 내화해석 (A Numerical Analysis of Steel Structures on a Subway Station Fire)

  • 방명석
    • 한국안전학회지
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    • 제25권6호
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    • pp.123-127
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    • 2010
  • A fire disaster is very serious in the closing space like subway station. In this study, the simulation on fire diffusion is performed to get the temperature history curve, which is used for the fire resisting structural analysis. Most of subway stations are built by the reinforced concrete structure, but recently steel structures are selected for the larger space or beauty. Steel structures relatively have more weaknesses against fire, so it is necessary to develop the method for evaluating fire-resisting capacity in this kind of structures. The developed method is applied to the subway station in Daegu city. It shows that the developed method can be used to simulate the fire disaster and to get the temperature history curve and evaluate the safety of steel structures against the fire.

폴드공간의 인지생태론적 특성과 그 효과 (The Cognitive Ecological Characteristics in Folded Space and Their Effects)

  • 김주미
    • 한국실내디자인학회논문집
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    • 제14권3호
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    • pp.181-190
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    • 2005
  • In accordance with the rapid growth of digital media in 1990s, the state of indetermination that is found in digital process has been emphasized in the field of natural science and philosophy. Digitalized space design has been dramatically developed and it raised heated debate and comment on 'folded space' The purpose of this thesis is to explore how the cognitive-ecological factors constitute fold structures in space design of the late 20th century. Syntax of space structure and geometric composition were analyzed to define what types of cognitive-ecological factors are contrived in the process of visual information. In particular, I put higher theoretical emphasis on what characteristics are ensued in the process of structuring spaces than any other subjects. Through theses analyses and discussions, I raised questions on what principles are operating to create new space design that counts on non-linear structure and its formational process. And I also observed what influences these structural principles of design could fundamentally bring to human beings. First, I proposed that we could overcome reductionist space design through cognitive-ecological approach. Some key concepts such as affordance, parallel processing, and redundancy were adopted as defining elements of non-linear structures. As a result of analyses, I found that the cognitive-ecological approach could substitute the reductionist space design of the past. What is also found is that the three variables are the ultimate ecological elements. In addition, as a methodological concept of fold structures, the form of 'topology' was highlighted because it could be a supporting idea to the cognitive-ecological factors. Second, I claimed that non-linear design is more experiential than rational linear design, and it is more efficiently correspondent to human being than any other forms. What is intended and implied in non-linear structure is also indicated.

DEFORMATION SPACES OF CONVEX REAL-PROJECTIVE STRUCTURES AND HYPERBOLIC AFFINE STRUCTURES

  • Darvishzadeh, Mehdi-Reza;William M.Goldman
    • 대한수학회지
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    • 제33권3호
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    • pp.625-639
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    • 1996
  • A convex $RP^n$-structure on a smooth anifold M is a representation of M as a quotient of a convex domain $\Omega \subset RP^n$ by a discrete group $\Gamma$ of collineations of $RP^n$ acting properly on $\Omega$. When M is a closed surface of genus g > 1, then the equivalence classes of such structures form a moduli space $B(M)$ homeomorphic to an open cell of dimension 16(g-1) (Goldman [2]). This cell contains the Teichmuller space $T(M)$ of M and it is of interest to know what of the rich geometric structure extends to $B(M)$. In [3], a symplectic structure on $B(M)$ is defined, which extends the symplectic structure on $T(M)$ defined by the Weil-Petersson Kahler form.

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해양공간이용구조물의 응답제어 (Control of Dynamic Reaponses of Huge Structures for Ocean Space Utilization in Waves)

  • 구자삼;홍봉기
    • 한국해양공학회지
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    • 제5권2호
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    • pp.16-30
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    • 1991
  • A numerical procedure is described for predicting the dynamic responses of combined systems of floating breakwaters and huge offshore structures supported by a large numer of the floating bodies in waves. The hydrodynamic interactins among tatal floating bodies are taken into account in their exact form within the context of linear potential theory. Wave control effects are discussed with both hydrodynamic interactions and hydrodynamic-structure interaction effects. The method presented is applicalbe to combined systems of floating breakwaters and huge structures for ocean space utilization for which a number of practical uses are seen in the future.

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해양공간이용구조물의 응답제어 (Control of Dynamic Reaponses of Huge Structures for Ocean Space Utilization in Waves)

  • 구자삼;홍봉기
    • 한국해양공학회지
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    • 제5권2호
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    • pp.156-156
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    • 1991
  • A numerical procedure is described for predicting the dynamic responses of combined systems of floating breakwaters and huge offshore structures supported by a large numer of the floating bodies in waves. The hydrodynamic interactins among tatal floating bodies are taken into account in their exact form within the context of linear potential theory. Wave control effects are discussed with both hydrodynamic interactions and hydrodynamic-structure interaction effects. The method presented is applicalbe to combined systems of floating breakwaters and huge structures for ocean space utilization for which a number of practical uses are seen in the future.