• Wind and Structures
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• 제31권3호
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• pp.185-196
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• 2020

A method to reduce the wind pressure at the leading edge of a noise barrier was investigated by gradually lowering the height of a member added to the end of the noise barrier. The shape of the lowered height of the added member was defined by its length and slope, and the optimal variable was determined in wind tunnel testing via the boundary-layer wind profile. The goal of the optimal shape was to reduce the wind pressure at the leading edge of the noise barrier to the level suggested in the Eurocode and to maintain the base-bending moment of the added member at the same level as the noise-barrier section. Using parametric wind tunnel investigation, an added member with a slope of 1:2 that protruded 1.2 times the height of the noise barrier was proposed. This added member is expected to simplify, or at least minimize, the types of column members required to equidistantly support both added members and noise barriers, which should thereby improve the safety and construction convenience of noise-barrier structures.

• Asia pacific journal of information systems
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• 제33권2호
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• pp.418-443
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• 2023

Many organizations facilitate a host of online knowledge sharing communities to assist internal knowledge sharing and operation. The permeable boundaries and voluntary structures of online communities allow individuals to span community boundaries and affect member resources and structures. Although much research has been done on members' knowledge contribution in online communities, relatively little is known about how a member's contribution to a community is shaped by the cross-level interactions of member's external boundary spanning and the community's environmental scanning or membership fluidity. Drawing from the theoretical lens of boundary spanning and the external view of online communities, we take a multi-level approach in the analysis of the activities of 1,992 members of 126 communities internal to a global company. We find that a member's external boundary spanning activity (e.g., external knowledge acquisition via reading posts) has a positive effect, though at a decreasing rate, on subsequent internal knowledge contribution (e.g., posting replies in the member's home community). This positive effect is stronger in communities that are more active in environmental scanning or have fluid membership and weaker in communities that are less active in environmental scanning or have stable membership.

• 한국공간구조학회논문집
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• 제11권2호
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• pp.139-149
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• 2011

케이블 구조물은 비교적 가볍고 넓은 공간의 형성이 쉬우나 유연한 특징으로 인해 형상의 제어가 매우 민감하다. 이런 구조물은 여러 이유에서 형상의 보정이 필요하며, 특히 부재 제어량과 어떠한 부재를 제어해야 하는가는 것은 많은 연구자들이 고심하고 있는 문제이다. 따라서 본 논문의 목적은 하중법(Force Method)를 이용해서 형상조절을 위한 변위 제어기법을 연구하는 것이다. 논문은 2장에서는 제어 방정식을 설명하고, 3장에서는 단순 케이블 넷 모델을 이용하여 동시 및 순차제어를 고려해 해석을 수행하고 결과를 고찰한다. 4장에서는 보다 더 복잡한 케이블 돔 구조물에 적용하여 가장 유용한 부재에 대해서 논의 하고, 5장에서 결과를 요약한다.

• 한국공간구조학회논문집
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• 제14권4호
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• pp.81-88
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• 2014

Construction of vinyl house structures is increasing because they do not have a large cross section as non-permanent structures. Vinyl house structures are apt to collapse by snow load because they have a small size member as a temporary building. Therefore, it is very important to ensure not only the stiffness of the individual member, but also the overall stability of three-dimensional arch-type vinyl house structures. The purpose of this study is to estimate the stability of arch-type vinyl house structures that have a various curvature under the vertical load such as snow load. As a result of the study, the buckling load of V27 model is the largest, and the values of buckling load have a tendency to increase with increasing H(height of arch) in the case of $H{\leq}2.75m$, but to decrease with increasing H in the case of $H{\geq}2.75m$.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2001년도 봄 학술발표회 논문집
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• pp.251-258
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• 2001

Cable and membrane structures can be classified as a unstable structure in the view point of shape determination process. An unstable stucture at the initial state generally cannot take a role as the resistance for the external force. Therefore, there should be a stabilizing process to get the stable state of a structure and it is necessary to visualize the shape finding from unstable state to stable state. In this paper, a numerical method of stabilizing procedure for the link structures is presented. The structures are assumed to have rigid movements and thus only changing of the topology of member is considered during the analysis. The generalized inverse matrix and the principle of minimum potential energy are used in the process. Illustrative examples are presented and the results show good convergence.

• Computers and Concrete
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• 제3권5호
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• pp.313-334
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• 2006

A novel formulation aiming to achieve optimal design of reinforced concrete (RC) structures is presented here. Optimal sizing and reinforcing for beam and column members in multi-bay and multistory RC structures incorporates optimal stiffness correlation among all structural members and results in cost savings over typical-practice design solutions. A Nonlinear Programming algorithm searches for a minimum cost solution that satisfies ACI 2005 code requirements for axial and flexural loads. Material and labor costs for forming and placing concrete and steel are incorporated as a function of member size using RS Means 2005 cost data. Successful implementation demonstrates the abilities and performance of MATLAB's (The Mathworks, Inc.) Sequential Quadratic Programming algorithm for the design optimization of RC structures. A number of examples are presented that demonstrate the ability of this formulation to achieve optimal designs.

• 대한토목학회논문집
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• 제28권4A호
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• pp.465-474
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• 2008

일반적으로, 보-기둥 부재로 구성된 강뼈대구조물의 설계는 개별부재의 유효좌굴길이를 고려하여 설계기준에서 제시한 안정성 평가식을 적용하고 있다. 그러나 이 방법은 구조물에서 상대적으로 작은 압축력이 적용되는 부재에서는 유효좌굴길이가 커지는 문제가 발생하게 된다. 이러한 문제를 극복하고자 본 연구에서는 대상 구조물의 초기결함(initial imperfection)을 고려한 2차 탄성해석법을 제시한다. 이 방법은 탄성좌굴 고유치해석으로 산정된 좌굴모드 및 좌굴고유치, 개별부재의 축력을 이용하여, 가장 작은 무차원 세장비를 가진 부재를 선정하고, 그 부재에 대하여 기하적, 재료적인 효과가 고려된 설계기준의 기준강도곡선으로부터 좌굴모드에 대한 증폭량을 산정한다. 이렇게 결정된 증폭량을 대상 구조물의 좌굴모드에 증폭시켜 2차 탄성해석을 수행하고, 개별부재의 안정성을 평가한다. 본 방법의 타당성을 확인하기 위하여, 8층 및 4층으로 이루어진 평면 강뼈대구조물에 적용시키고, 설계기준에서 제시하는 안정성 평가법과 비교한다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 봄 학술발표회 논문집
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• pp.165-172
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• 1998

The development of Reinforced Concrete member design modules is necessary for user to design structures easily. The purpose of this paper is to be available for a integrated system used structure design. This module is linked with central database for the benefit of minimizing time of design and user's efforts. In order to minimize memory space, all of data is stored in central database. Member design modules applied Object-Oriented concepts are possible to be reusible, flexible for member functions in classes. This modules can be operated both independent member design modules and a part of integrated system. Sooner or later, this modules will be related to member grouping modules by data.

• 한국공간구조학회논문집
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• 제13권4호
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• pp.75-81
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• 2013

The circular hollow section is usually used for member of main frame to carry the external load in single layer lattice dome. But, the H-shaped section may be used for member of main frame since it is convenient for attaching roof panels. Single layer lattice domes have various buckling characteristics, such as the overall buckling, the member buckling, and nodal buckling. The purpose of this study is to compare buckling characteristics of single-layer lattice domes in which the H-shaped steel section as the existing domestically-produced structural steel is used as main frames to those of domes in which a circular hollow section is used as main frames.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2004년도 가을 학술발표회 논문집
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• pp.363-370
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• 2004

This Paper presents the response force distribution factor(RDF) and its application to recalculation of member forces in case of partial changes of structures. Using RDF, the mutuality of response forces between members can be estimated. The reanalysis technique recalculates directly any displacement or member force under consideration in real time without a full reanalysis in spite of local changes in member stiffness or connectivity using RDF. It is expected that RDF and the reanalysis technique can be used to develop efficient analysis techniques for tall buildings.