• Journal of the Korea institute for structural maintenance and inspection
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• v.8 no.4
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• pp.175-183
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• 2004

The most important element is a rise ratio when regarding beauty and economics of arch bridges. Only the effect of dead load has been considered to decide the rise ratio. In this study, when going over the rise ratio of arch bridges, examined the problems, that the determination of the rise ratio by the dead load has, by adding the factor of a determination of optimum rise ratio, which is not only the effect of the dead load that has been currently considered but also the problem with respect to dynamic stability that is now taken seriously. Synthetically, when deciding rise ratio that is investigated in basic step of design, it is necessary to consider the evaluation dynamic stability.

• Proceeding of KASS Symposium
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• 2008.05a
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• pp.127-132
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• 2008

Recent years, the response characteristics of large space structures have been studied. Then, for the large space structures with large rise-span ratio, it is clarified that the anti-symmetric mode are representatively amplified. That means the static seismic load for general ramen structure is not suitable for the space structure. In this paper, we propose static seismic loads for space structures and its concept. And for the space structures of beam string structures, execute the time history analysis and quasi static analysis and compare the results of them. From the results, we can prove the validity of static seismic load for space structure.

• Journal of Korean Society of Steel Construction
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• v.14 no.2
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• pp.319-327
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• 2002

Development of high-strength and light-weight structural steel as well as advancement in steel structure analysis enable construction of long span steel arch bridge. In an economic viewpoint, however, the design values of long span steel arch bridge needs to be optimized to reduce construction cost and achieve proper levels of structural safety. This study investigated the girder depth and the rise-span ratio for optimum design values, as well as the spectral analysis for protection against earthquake. The relationship between rise-span ratio and girder depth was derived based on the parametric studies of the basic span lengths of 60, 70, 80, 90, and 100m using a commercial Cis SAP2000. The equation relating the two variables was derived using linear regression.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06d
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• pp.79-81
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• 2006

웹데브(Web-based Distributed Authoring and Versioning)는 원거리에 있는 사용자들 간에 인터넷을 통하여 파일을 공동 저작하고 관리할 수 있도록 지원하는 IETF 표준의 HTTP 확장 프로토콜이다. 웹데브 프로토콜이 발표된 이후 이를 지원하는 다수의 웹데브 서버와 클라이언트가 개발되었으며, 웹데브 클라이언트를 효율적으로 개발하기 위해서는 웹데브 프로토콜을 지원하는 서버의 자원에 대한 HTTP 요청/응답 처리를 담당하는 라이브러리가 지원되는 것이 바람직하다. 본 논문에서는 윈도우즈 웹데브 클라이언트의 효과적인 HTTP 요청/응답 처리를 위한 라이브러리의 개발에 대하여 기술한다. 개발된 라이브러리는 $C{\sharp}$ 언어를 사용하여 객체 지향 기법으로 설계되었고 웹데브 기본 메소드를 지원하며 특히 속성 관리를 위한 클래스를 제공하여 웹데브 속성 관리를 효과적이로 지원한다. 또한 .NET Framework에서 제공하는 XMLHTTP30 클래스와 XmIDocument 클래스를 사용하여 HTTP 요청을 비동기적으로 처리함으로써 클라이언트의 병행성을 효율적으로 지원한다.

• Journal of Korean Society of Steel Construction
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• v.24 no.3
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• pp.337-348
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• 2012

This study investigated the characteristics of bifurcation and the instability due to the initial imperfection of the space truss, which is sensitive to the initial conditions, and the calculated buckling load by the analysis of Eigen-values and the determinant of tangential stiffness. A two-free nodes model, a star dome, and a three-ring dome model were selected as case studies in order to examine the unstable phenomenon due to the sensitivity to Eigen mode, and the influence of the rise-span ratio and the load parameter on the buckling load were analyzed. The sensitivity to the imperfection of the two-free nodes model changed the critical path after reaching the limit point through the bifurcation mode, and the buckling load level was reduced by the increase in the amount of imperfection. The two sensitive buckling patterns for the model can be explained by investigating the displaced position of the free node, and the asymmetric Eigen mode was a major influence on the unstable behavior due to the initial imperfection. The sensitive mode was similar to the in-extensional mechanism basis of the simplified model. Since the rise-span ratio was higher, the effect of local buckling is more prominent than the global buckling in the star dome, and bifurcation on the equilibrium path occurring as the value of the load parameter was higher. Additionally, the buckling load levels of the star dome and the three-ring model were about 50-70% and 80-90% of the limit point, respectively.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1992.10a
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• pp.127-132
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• 1992

The effect of 5 typical rise ratio(h/a=2/9, 5/18, l/3, l/2, 2/3) on the buckling characteristics of single-layer latticed domes with rectangular network under the external pressure are the theoretically studied on the basis of geometically nonlinear FEM and shell analogy method. The loading conditions are 4 types, that is, 1) the uniform pressure loading 2)the uniform snow loading 3) the half - sided asymmetric pressure loading 4) the half - sided asymmetric snow loading.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11b
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• pp.1209-1212
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• 2002

대규모 네트워크 게임은 최대한 많은 사용자를 수용할 수 있어야 하며 사용자들에게 안정적인 서비스를 제공할 수 있어야 한다. 그러나 많은 사용자들의 서버 동시 접속 및 제한된 네트워크 대역폭 등의 문제들로 인해 네트워크 게임 서버는 부하가 걸릴 수 있다. 이런 부하를 최대한 줄이기 위해 네트워크 게임 서버는 기능별로 분산되어 있는 것이 일반적이며, 분산된 서버들간의 통신 또는 서버와 클라이언트들간의 통신은 운영체제에서 제공하는 네트워크 통신 라이브러리를 사용한다. 본 논문에서는 Microsoft 사의 윈도우즈 계열에서 제공하는 다섯 가지 소켓 I/O 모델들에 대해 조사하고 비교 분석한다. 비교 분석한 결과 대규모 네트워크 게임 환경에서는 IOCP 모델이 기타 소켓 모델에 비해 IO 처리가 여러 가지 장점을 가지고 있음을 알 수 있다.

• Journal of Korean Association for Spatial Structures
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• v.19 no.2
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• pp.51-61
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• 2019

The objective of this study is to analysis the seismic response of 200m spanned honeycomb lattice domes under horizontal and up-down ground motion of El Centro earthquake. For the analysis of seismic response of the honeycomb lattice domes by rise/span ratio, the time history analysis is used for the estimation of the dynamic response. The low rise lattice dome is less deformed and less stressed than the high rise lattice dome for the earthquake ground motion. The 3-dimensional earthquake response is not significantly different the dynamic response of one directional ground motion. The earthquake response of domes with LRB isolation system is significantly reduced for the asymmetric vertical deformation and the horizontal and vertical accelerations.

• Journal of Korean Association for Spatial Structures
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• v.24 no.2
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• pp.101-109
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• 2024

In this study, the characteristics of wind pressure distribution on circular retractable dome roofs with a low rise-to-span ratio were analyzed under various approaching flow conditions by obtaining and analyzing wind pressures under three different turbulent boundary layers. Compared to the results of previous studies with a rise-to-span ratio of 0.1, it was confirmed that a lower rise-to-span ratio increases the reattachment length of the separated approaching flow, thereby increasing the influence of negative pressure. Additionally, it was found that wind pressures varied significantly according to the characteristics of the turbulence intensity. Based on these experimental results, a model for peak net pressure coefficients for cladding design was proposed, considering variations in turbulence intensity and height.

• Journal of Korean Society of Steel Construction
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• v.18 no.4
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• pp.427-436
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• 2006

The classical buckling theory assumes that prebuckling behavior is linear and that the effect of prebuckling deformations on buckling can be ignored. However, when the rise to span ratio decreases, prebuckling deformation cannot be ignored and the symetrical buckling strength can be smaler than the asymetrical buckling strength. Finally, arches can fail due to snap-through buckling. This paper investigates the non-linear behavior and strength of pin-ended parabolic shallow arches using the non-linear governing differential equation of shallow arches. These results were compared with the solution for the symmetrical buckling load of pin-ended parabolic shallow arches was suggested.