• 제목/요약/키워드: Form Evolution

검색결과 532건 처리시간 0.031초

The Evolution of Outrigger System in Tall Buildings

  • Ho, Goman W.M.
    • 국제초고층학회논문집
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    • 제5권1호
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    • pp.21-30
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    • 2016
  • The structural efficiency of tall buildings heavily depends on the lateral stiffness and resistance capacity. Among those structural systems for tall buildings, outrigger system is one of the most common and efficient systems especially for those with relatively regular floor plan. The use of outriggers in building structures can be traced back from early 50 from the concept of deep beams. With the rise of building height, deep beams become concrete walls or now in a form of at least one story high steel truss type of outriggers. Because of the widened choice in material to be adopted in outriggers, the form and even the objective of using outrigger system is also changing. In the past, outrigger systems is only used to provide additional stiffness to reduce drift and deflection. New applications for outrigger systems now move to provide additional damping to reduce wind load and acceleration, and also could be used as structural fuse to protect the building under a severe earthquake condition. Besides analysis and member design, construction issue of outrigger systems is somehow cannot be separated. Axial shortening effect between core and perimeter structure is unavoidable. This paper presents a state-of-the-art review on the outrigger system in tall buildings including development history and applications of outrigger systems in tall buildings. The concept of outrigger system, optimum topology, and design and construction consideration will also be discussed and presented.

COSMIC RAY ACCELERATION AT COSMOLOGICAL SHOCKS

  • KANG HYESUNG;JONES T. W.
    • 천문학회지
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    • 제37권5호
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    • pp.405-412
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    • 2004
  • Cosmological shocks form as an inevitable consequence of gravitational collapse during the large scale structure formation and cosmic-rays (CRs) are known to be accelerated at collisionless shocks via diffusive shock acceleration (DSA). We have calculated the evolution of CR modified shocks for a wide range of shock Mach numbers and shock speeds through numerical simulations of DSA in 1D quasi-parallel plane shocks. The simulations include thermal leakage injection of seed CRs, as well as pre-existing, upstream CR populations. Bohm-like diffusion is assumed. We show that CR modified shocks evolve to time-asymptotic states by the time injected particles are accelerated to moderately relativistic energies (p/mc $\ge$ 1), and that two shocks with the same Mach number, but with different shock speeds, evolve qualitatively similarly when the results are presented in terms of a characteristic diffusion length and diffusion time. We find that $10^{-4} - 10^{-3}$ of the particles passed through the shock are accelerated to form the CR population, and the injection rate is higher for shocks with higher Mach number. The CR acceleration efficiency increases with shock Mach number, but it asymptotes to ${\~}50\%$ in high Mach number shocks, regardless of the injection rate and upstream CR pressure. On the other hand, in moderate strength shocks ($M_s {\le} 5$), the pre-existing CRs increase the overall CR energy. We conclude that the CR acceleration at cosmological shocks is efficient enough to lead to significant nonlinear modifications to the shock structures.

함경도 출신 조선족 농촌주거의 공간적 특성과 변천에 관한 실태조사연구 (A Research on The Spatial Characteristics and Changes in Farmhouses of Ethnic Korean Chinese Origined From Ham-kyeong do)

  • 김일학;장위쿤
    • 한국주거학회논문집
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    • 제27권1호
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    • pp.13-20
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    • 2016
  • The paper takes the rural housings of the Chaoxian nationality of Ham-kyeongdo in the three provinces in Northeast China as research object, to discuss the spatial form andthe characteristic of the change in the housing. The research result shows that the dwellings' plane forms in the Tumen River, the coast of Yalu River and the Sino Russian border are mainly traditional "Jeong-ji central type (J)", while in Heilongjiang are mainly "Jeong-ji and corridor central type (J-C)". In the evolution of living space and behavior patterns, there appears sliding door and partition between Jeongjibang and kitchen in the former, and Badang space in the front of the Kang and the behavior pattern remains its original seat-type lifestyle mainly. While there forms Dikang space and living space in the process of different cultures blend and modernization in the later and appears some upright-type behavior patterns. There is distinct characteristic in regional changes in both.

한국산 Epistylis속 섬모충류의 2미기록종(섬모충문: 소막충강: 주모목) (Two Newly Recorded Epistylis Ciliate Species (Ciliophora: Oligohymenophora: Peritrichida) from Korea)

  • Youn Kyung Cho;Mann Kyoon Shin
    • Animal Systematics, Evolution and Diversity
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    • 제19권2호
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    • pp.237-244
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    • 2003
  • 울산 인근의 연못 가장자리 수초에서 채집된 섬모충류가 겹가지섬모충과 (Epistylidae)에 속하는 겹가지섬모충(Epistylis plicatilis Ehrenberg, 1831)과 빈겹가지섬모충 (E. hentscheli Kahl, 1935)으로 각각 동정되어 재기재하였다. 이 종들은 한국에서 처음 보고되는 종들로서 생체표본과 protargol로 염색한 표본에 근거하여 재기재하였다. 원기재와 유사종들과 비교하였는데 겹가지섬모충 (E. plicatilis)은 가늘고 긴 깔대기 형태를 가지며 줄기는 근섬유로 속이 찬 형태이다. 반면에 빈겹가지섬모충 (E. hentscheli)는 비대칭의 종 모양을 띠며 줄기는 속이 텅 빈 형태이다.

토양수분과 식생 스트레스 동역학에 기후변화가 미치는 영향 (The Impact of Climate Change on the Dynamics of Soil Water and Plant Water Stress)

  • 한수희;김상단
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2009년도 학술발표회 초록집
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    • pp.52-56
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    • 2009
  • In this study a dynamic modeling scheme is presented to derive the probabilistic structure of soil water and plant water stress when subject to stochastic precipitation conditions. The newly developed model has the form of the Fokker-Planck equation, and its applicability as a model for the probabilistic evolution of the soil water and plant water stress is investigated under climate change scenarios. This model is based on the cumulant expansion theory, and has the advantage of providing the probabilistic solution in the form of probability distribution function (PDF), from which one can obtain the ensemble average behavior of the dynamics. The simulation result of soil water confirms that the proposed soil water model can properly reproduce the results obtained from observations, and it also proves that the soil water behaves with consistent cycle based on the precipitation pattern. The plant water stress simulation, also, shows two different PDF patterns according to the precipitation. Moreover, with all the simulation results with climate change scenarios, it can be concluded that the future soil water and plant water stress dynamics will differently behave with different climate change scenarios.

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비결합 다관절 평면기구의 컴퓨터원용 운동해석을 위한 컴포넌트 모듈기법 (Component Modular Approach to Computer-Aided Kinematic Analysis for General Planar Uncoupled-Connected Multiloop Mechanisms)

  • 신중호
    • 대한기계학회논문집
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    • 제17권8호
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    • pp.1883-1897
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    • 1993
  • Interactive computer-aided analysis of mechanical systems has recently been undergoing an evolution due to highly efficient computer graphics. The industrial implementation of state-of-the-art analytical developments in mechanisms has been facilitated by computer-aided design packages because these rigid-body mechanism analysis programs dramatically reduce the time required for linkage design. This paper proposes a component modular approach to computeraided kinematic motion analysis for general planar multiloop mechanisms. Most multiloop mechanisms can be decomposed into serveral components. The kinematic properties (position, velocity, and acceleration) of every node can then be determined from the kinematic analysis of the corresponding component modules by a closed-form solution procedure. In this paper, 8 types of modules are defined and formulations for kinematic analysis of the component modules are derived. Then a computer-aided kinematic analysis program is developed using the proposed approach and the solution procedure of an example shows the effectiveness and accuracy on the approach.

루이스 칸 건축공간의 빛의 특성 고찰 (A Study on the Characteristic of the Light in Louis I. Kahn's Architectural Space)

  • 임호균
    • 한국실내디자인학회논문집
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    • 제14권5호
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    • pp.114-122
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    • 2005
  • A study of light in Kahn's architecture must be significance as a work in building new architectural space and a new foundation for architecture, as well as clarification of the uniqueness of Kahn's architectural space and search for its significance. In addition, the study provides a greater comprehension of an the concept of Kahn's architecture by clarifying the degree of association of light into other concepts of architecture. Therefore, this study attempts to examine Louis I. Kahn's statement, sketch and work. His sketch along with the characteristics of the technique how to present it also enables comprehension of other aspects of architecture as a means to revive architecture. Khan's use of light enabled the evolution of primarily two types 'specular surface' and 'unique opening part' by associating them with the need to diminish glaringness. Each of these types has been evolved individually and is indicative of a concept of light that can be largely divided into ' object's light ' and ' space's light ' Object's light refers to a type in which the formative significance of structural part and different directions of light coexist, and its formative characteristics play a role that differentiate places within space. Space's light is present on wall spaces that limit space and exhibits its distinguished role differentiating places within space in the form of 'expression'.

한국 유령해면속 (보통해면강: 다골해면목: 유령해면과)의 2신종 (Two New Marine Sponges of Genus Clathria (Clathria) (Poecilosclerida: Microcionidae) from Korea)

  • 김형준;심정자
    • Animal Systematics, Evolution and Diversity
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    • 제21권1호
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    • pp.111-122
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    • 2005
  • 울릉도와 가거도에서 2001년 10월과 2000년 7월에 SCVBA 다이빙으로 채집된 해면동물을 동정$\cdot$분류한 결과 유령해면속 (Clathria)의 곰바위유령해면[Clathria (Clathria) gombawuiensis n. sp.]과 가거유령해면 [ Clathria ( C.) gageoensis n. sp.]이 신종으로 밝혀졌다. 곰바위유령해면은 Clathria (C.) conica와 골편의 구성에 있어서는 유사하지만 골편의 크기와 성장형태에 있어서 많은 차이가 있었으며, Clathria (C.) conica는 작은 toxa를 가지지 않는다. 가거유령 해면은 Clathria (C.) hexagonopora와 유사하지만 골편의 크기와 성장형태가 다르고, Clathria (C.) hexagonopora는 작은 toxa를 가지지 않는다.

First Record of Two Euplotes Ciliates (Ciliophora: Spirotrichea: Euplotida) from Korea

  • Park, Mi-Hyun;Kim, Se-Joo;Min, Gi-Sik
    • Animal Systematics, Evolution and Diversity
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    • 제26권1호
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    • pp.21-27
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    • 2010
  • Two marine euplotid ciliates, i.e. Euplotes cristatus Kahl, 1932 and E. minuta Yocom, 1930, were collected from the public waterfront of Incheon on the Yellow Sea and from the Songjeong Beach, Busan, in the Strait of Korea, respectively. These two species were verified as unrecorded species in Korea. These species were described based on live observation, protargol impregnation, and silver nitrate impregnation. In addition, the small subunit ribosomal DNA (SSU rDNA) sequences of the two species were compared with previously known sequences of the Euplotes species. Euplotes cristatus has an elongated oval form, size in vivo of $60-84{\times}38-68\;{\mu}m$, 35-50 adoral zone of membranelles (AZM), 10 frontoventral cirri (FVC), 5 transverse cirri (TC), 4-5 caudal cirri (CC), 8 dorsal kineties (DK), 10-16 dorsal cilia of middle DK, and silverline system of single-vannus type. Euplotes minuta has a small ovoid form ($44-53{\times}26-35\;{\mu}m$ in vivo), 31-41 AZM, 10 FVC, 5 TC, 4 CC, 9 DK, 10-12 dorsal cilia of middle DK, and silverline system of single-vannus type.

얇은 접합층의 계면균열에 대한 이론적 해석 (Theoretical Analysis of Interface Crack on Thin Plate)

  • 노환진
    • 대한조선학회논문집
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    • 제44권6호
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    • pp.627-634
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    • 2007
  • A bonded plate or a coated part can be debonded by external impact or thermal expansion. To analyse adhesive strength, the blister test is generally adopted. In this paper, a blister test is modelled theoretically and then the stability and bifurcation of the blister are studied under several different cases. The blister is simplified to consist of a pure bending plate attached elastically to the rigid substrate. Expression of the energy release rate is obtained as a form of an explicit function for a circular-type blister or tunnel-type blister grown by controlling the internal pressure or internal volume. Stability and bifurcation are also studied in the frame of the quasi-static evolution. The study shows that the circular- type blister propagates with the first mode of bifurcation and that the tunnel-type blister propagates with a regular wave. It is proved that the waves have the same form on two side lines of the tunnel and that the wave length can be obtained. When the internal pressure is controlled, the blister is unstable, but when the internal volume is controlled, it is stable.