• Title/Summary/Keyword: structural importance

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The Evaluation of Wind-induced Pressure for the Shell Structures using Computational Fluid Dynamics (전산유체역학을 이용한 셸 구조의 형상에 따른 풍압 평가)

  • Han, Sang-Eul;Park, Ji-Seon
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2008.04a
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    • pp.579-584
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    • 2008
  • The importance and the interest of wind load have emphasized since the damage of the Jeju World cup Stadium and Main Stadium of Busan Asiad in 2002, and the appearance of high-rise buildings. In general, a evaluation for the wind load acting on structures have been carried out mainly through the wind tunnel test, but this technique has the huge shortcomings that consume too much cost and experimental time. However, with the rapid advances on computers, it is possible to analyze the wind pressure distribution acting on structures by numerical scheme. In this paper, to predict the wind pressure distribution acting on shell structures having the various shape by numerical simulation, governing equations of fluid flow and turbulent model is formulated. Also, evaluates the wind pressure coefficient in accordance with the structural shape for shell structures like as a membrane structures and dome structures.

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Structural Correlations among Director's Servant Leadership, Teacher's Ego-Resilience and Organizational Commitment in Early Childhood Education Center (원장의 서번트 리더십, 유아교사의 자아탄력성 및 조직몰입 간의 구조적 관계)

  • Oh, Seung-Hyun;Kwon, Yeon-Hee
    • Korean Journal of Childcare and Education
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    • v.13 no.1
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    • pp.1-17
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    • 2017
  • Objective: The purpose of the present study was to investigate the structural relations among kindergartens director's servant leadership, ego resilience and organizational commitment of kindergarten teachers. Methods: The subjects in this study were 387 kindergarten teachers working in B city. A director's servant leadership, kindergarten teacher's ego resilience and organizational commitment were assessed by a teacher-reported questionnaire. The collected data were analyzed using descriptive statistics, Pearson's product-moment correlation, and a structural equation model using the Bootstrapping method. Results: First, there were significant relationships among the variables analyzed in this research, namely, a director's servant leadership, kindergarten teacher's ego resilience and organizational commitment. Second, Teacher's ego resilience partially mediated the effect of a director's servant leadership upon kindergarten teacher'organizational commitment. Conclusion/Implications: Results suggest the importance of a director's role in the context of improving kindergarten teacher's ego resilience and organizational commitment.

Workflow of Cryo-Electron Microscopy and Status of Domestic Infrastructure

  • Choi, Ki Ju;Shin, Jae In;Lee, Sung Hun
    • Applied Microscopy
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    • v.48 no.1
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    • pp.6-10
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    • 2018
  • Cryo-electron microscopy (cryo-EM) allows the analysis of the near-native structures of samples such as proteins, viruses, and sub-cellular organelles at the sub-nano scale. With the recent development of analytical methods, this technique has achieved remarkable results. The importance of cryo-EM gained wide recognition due to last year's award of the Nobel Prize in Chemistry. To help promote the knowledge of this technique, this paper introduces the basic workflows of cryo-EM and domestic cryo-EM service institutes.

Effects of ground motion scaling on nonlinear higher mode building response

  • Wood, R.L.;Hutchinson, T.C.
    • Earthquakes and Structures
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    • v.3 no.6
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    • pp.869-887
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    • 2012
  • Ground motion scaling techniques are actively debated in the earthquake engineering community. Considerations such as what amplitude, over what period range and to what target spectrum are amongst the questions of practical importance. In this paper, the effect of various ground motion scaling approaches are explored using three reinforced concrete prototypical building models of 8, 12 and 20 stories designed to respond nonlinearly under a design level earthquake event in the seismically active Southern California region. Twenty-one recorded earthquake motions are selected using a probabilistic seismic hazard analysis and subsequently scaled using four different strategies. These motions are subsequently compared to spectrally compatible motions. The nonlinear response of a planar frameidealized building is evaluated in terms of plasticity distribution, floor level acceleration and uncorrelated acceleration amplification ratio distributions; and interstory drift distributions. The most pronounced response variability observed in association with the scaling method is the extent of higher mode participation in the nonlinear demands.

A Study on the Behavior of Prestressed Concrete Box Girder Bridges According to material Properties (재료특성치의 변화로 인한 프리스트레스트 콘크리트 박스거더 교량의 거동분석)

  • 오병환;양인환;김의성;최인혁;김세훈
    • Proceedings of the Korea Concrete Institute Conference
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    • 1997.10a
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    • pp.627-632
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    • 1997
  • Recently, the prestressed concrete box girder bridges are increasingly built at various locations in the world. The mechanical and structural behavior of prestressed concrete brides varies because of time-dependent material properties and sequential change of structural system due to stepwise construction. The time-dependent behavior of concrete is of importance in the design and construction of segmentally constructed and cast-in-place prestressed concrete box girder bridges. The structural response is affected b variations in creep, shrinkage properties of concrete. In this study, the example of time-dependent deformations is extended to establish how the variability in concrete properties affects the accuracy of the calculated deformations in such a bridge, and finally the results are discussed.

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Solution for the Improvement in Structural Design & Application of PEB System for the Standard Livestock Housing(2008) (표준축사 모델에서 PEB시스템의 적용 및 구조설계 개선방안)

  • Park, Man-Woo;Do, Byung-Ho;Song, Jun-Ik
    • Journal of Animal Environmental Science
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    • v.15 no.1
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    • pp.17-28
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    • 2009
  • PEB system is more economical when compared with structures commonly used Hot rolled and welded light H-beam was introduced in the Standard Livestock Housing. This study suggested more economical technology for structural design by the reduction of live load, relief of deflection limit and reduction of importance factor. And, when applying wind Load as a result of examination with Low Rise Building Systems Manual considering open model, we can know that when the wind load is big, enclosed model is more stable than open model. In short, Suggesting more economical model and providing the method to reduce natural disaster, by the application of PEB system and the development of technology for structural design, are considered to strengthen the competitive power of farmhouse.

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A Study on the Optimum Structural Design for Oil Tankers Using Multi-Objective Optimization

  • Jang, Chang-Doo;Shin, Sang-Hun
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1998.04a
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    • pp.245-253
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    • 1998
  • Recently, the importance of multi-objective optimization techniques and stochastic search methods is increasing. The stochastic search methods have the concepts of the survival of the fittest and natural selection such as genetic algorithms(GA), simulated annealing(SA) and evolution strategies (ES). As many accidents of oil tankers cause marine pollution, oil tankers of double hull or mid deck structure are being built to minimize the marine pollution. For the improvement of oil tanker design technique, an efficient optimization technique is proposed in this study. Multi-objective optimization problem of weight and cost of double hull and mid deck tanker is formulated. Discrete design variables are used considering real manufacturing, and the concept of relative production cost is also introduced. The ES method is used as an optimization technique, and the ES algorithm was developed to generate a more efficient Pareto optimal set.

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Comparison of stress analysis tools for ocean vertical pile under environmental loads (해양 수직 파일(Vertical Pile)에 작용하는 환경 하중하의 응력 해석 기법 비교)

  • 조철희;김병환;김두홍
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2001.04a
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    • pp.121-127
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    • 2001
  • To investigate the stability and integrity of offshore structures, it is necessary to estimates the significant ocean environmental loadings. They include hydrostatic pressure, wind, wave, current, tide, ice, earthquake, temperature, marine growth and scouring. Waves are of major importance among them because of the large forces acting on submerged parts of the structure caused by accompanying water motions. For the comparison of stress and deflection analysis tools, a vertical pile is applied under environmental loads. The analysis is concerned with SACS(Structural Analysis Computer System), ANSYS and C program. SACS and C program have nearly the same results but not ANSYS. This study shows the comparison of results obtained from 3 different approaches.

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Support Deflection Effects in Slabs with Beam and Girder (보-거더 시스템 슬래브에서 지지부 처짐영향에 관한 연구)

  • 곽효경;송종영
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1997.10a
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    • pp.55-62
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    • 1997
  • The support deflection effects in slabs with beams and girders are reviewed for both cases of the uniformly distributed and concentrated wheel loads. The differences in structural behavior according to the variation of support stiffness namely, the moment of inertia of beam and gilder, and the slab thickness, are calculated using the finite element method. Besides. the correction factors which can consider the support deflection effects in slab design are proposed by regression based on the obtained numerical results. Through the comparision studies of slabs with different boundary conditions, the importance for the consideration of support deflection effects in design are emphasized.

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Development of State Assessment System of Low-Rise Reinforced Concrete Buildings to Remodeling (리모델링을 위한 기존 저층형 콘크리트 구조물의 상태평가시스템 개발)

  • Kim, Jin-Soo;Kim, Chang-Eun
    • Journal of the Korean Society of Safety
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    • v.18 no.4
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    • pp.115-123
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    • 2003
  • Remodeling is not subject to strict laws or regulations for permission procedure and structure safety inspection compared with new construction. Most of building owners do not recognize the importance of structural safety enough and place an order to small unlicensed construction company. As a result, important structural materials are damaged without enough investigation into permitted durability and fixed weight and load weight increase. This study suggests a system that can evaluate the state of the building and enables fast judgment on needs of repairing or strengthening as well as needs structural examination.