• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.5
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• pp.33-41
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• 2011

In this paper, we propose a lossless compression scheme for cloud point data of the target construction by using doubleness and decreasing useless information of cloud point data. We use Hough transform to find the horizontal angle between construction and terrestrial LIDAR. This angle is used for the rotation of the cloud point data. The cloud point data can be parallel to x-axis, then y-axis doubleness is increased. Therefore, the cloud point data can be more compressed. In addition, we apply two methods to decrease the number of cloud point data for useless information of them. One is decimation of the cloud point data, the other is to extract the range of y-coordinates of target construction, and then extract the cloud point data existing in the range only. The experimental result shows the performance of proposed scheme. To compress the data, we use only the position information without additional information. Therefore, this scheme can increase processing speed of the compression algorithm.

• Journal of the Earthquake Engineering Society of Korea
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• v.7 no.5
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• pp.93-102
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• 2003

An optimal design method for hybrid structural control system of building structures subject to earthquake excitation is presented in this paper. Designing a hybrid structural control system may be defined as a process that optimizes the capacities and configuration of passive and active control systems as well as structural members. The optimal design proceeds by formulating the optimization problem via a multi-stage goal programming technique and, then, by finding reasonable solution to the optimization problem by means of a goal-updating genetic algorithm. In the multi-stage goal programming, design targets(or goals) are at first selected too correspond too several stages and the objective function is th n defined as the sum of the normalized distances between these design goals and each of the physical values, that is, the inter-story drifts and the capacities of the control system. Finally, the goal-updating genetic algorithm searches for optimal solutions satisfying each stage of design goals and, if a solution exists, the levels of design goals are consecutively updated to approach the global optimal solution closest too the higher level of desired goals. The process of the integrated optimization design is illustrated by a numerical simulation of a nine-story building structure subject to earthquake excitation. The effectiveness of the proposed method is demonstrated by comparing the optimally designed results with those of a hybrid structural control system where structural members, passive and active control systems are uniformly distributed.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.15 no.2
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• pp.329-339
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• 2002

This research presents a systematic design procedure for supplemental viscoelastic dampers required to satisfy the given performance objectives using capacity spectrum method. To obtain required damper size, the amount of supplemental damping was computed from effective damping minus equivalent damping and inherent damping of structure. In the case of viscoelastic damper, iterative procedure is required because of the inherent stiffness of the damper. To verify the design method proposed in this study, parametric studies were performed for single degree of freedom systems with design variables. The method was also applied to a 10-story steel framed structure and the earthquake responses were obtained. According to time history analysis result the controlled displacements turned out to be close to the target displacement regardless of the design parameters.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.3
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• pp.143-151
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• 2009

In this paper, a new extraction algorithm for artificial structure in 3D cloud points of terrestrial LIDAR is described, considering that various obstacles in terrestrial LIDAR make it difficult to apply conventional algorithms which are designed for air-born LIDAR data. Firstly we use the R, G, B color information from the terrestrial LIDAR data to discriminate among the massive 3D cloud points. Hough transform is then applied to estimate the straight lines that correspond to the target structure. Finally, the structure is extracted by comparing the distance between the estimated line and 3D cloud points. The proposed algorithm is efficient in the sense that it requires the user interaction only when the reference colors are obtained. Computer simulation shows the performance to be quite satisfactory.

• Journal of Korean Society of Steel Construction
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• v.18 no.5
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• pp.585-596
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• 2006

This study focuses on the seismic behavior of 3-, 9-, and 20-story steel moment resisting frame (MRF) structures designed in accordance with the 2000 International Building Code using different Response Modification factors (R factors), i.e., 8, 9, 10, 11, and 12. For a detailed case study, 30 different structures were evaluated for 20 ground motions representing the hazard level, which is equal to a 2% probability in 50 years (2% in 50 years). The results showed that the current R factors provide conservative designs for the 3- and 9-story buildings for the Collapse Prevention performance objective. the 20-story buildings, which were designed without using the minimum requirement of spectral acceleration CS prescribed in IBC 2000, did not satisfy the seismic performance for Collapse Prevention performance.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1999.04a
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• pp.86-93
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• 1999

구조 설계지원 시스템의 최종적인 목표는 설계의 진행 시, 수없이 발생하는 선택의 과정이 구조물 품질 향상의 방향으로 이루어 질 수 있도록 하는 것이다. 이를 위해서는 두 가지의 해결 방안이 필수적이다. 하나는 구조 설계지원 시스템이 담당해야 하는 설계영역을 고객의 요구조건으로부터 최종 해결안을 도출시키는 차원까지 확대시켜야 하며, 두 번째는 품질을 정의하는 구조물의 성능이 다양하면서 서로 상반되기 때문에 이들을 동시에 만족시켜줄 수 있는 방안을 모색해야 한다는 점이다. 본 논문에서는 이러한 문제점을 해결할 수 있는 구조 설계지원시스템을 특히 Grid-like 타입의 구조물에 관하여 논의하고자 한다.

• Journal of the Earthquake Engineering Society of Korea
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• v.14 no.3
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• pp.1-10
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• 2010

The target performance of a current seismic design code is to achieve collapse-prevention in order to minimize casualties. Existing structures are also being retrofitted to meet this target performance. This seismic performance seems to have been achieved in recent great overseas earthquakes, but the accompanying enormous economic loss is pointed out as a new problem. A new seismic design concept over the current target performance is required to reduce economic loss, in which a target performance is determined by the damage probability in order to control the damage levels of structures. In this study, the seismic behavior of bridges having different characteristics was investigated by nonlinear seismic analyses, and fragility curves with respect to a reference damage level were derived. Based on these results, the characteristics of target ductilities satisfying a target damage probability were investigated.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.1
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• pp.223-230
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• 2006

In this paper the method for repair LCC evaluation of reinforced concrete structures deteriorated by chloride attack was constructed. Also, the FEM analysis for chloride ion penetration into concrete was conducted to evaluate the repair LCC which was decided by the number of repair times including early stages of construction and repair construction during the service life of structures. As a result, the number of repair times is obtained from the comparing the concentration of the chloride ion in a rebar position, and the critical chloride ion concentration of rebar corrosion through the FEM analysis considering the kind of repair materials and methods. Also, the repair LCC could be calculated by the number of repair times during the service life of structures.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.3
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• pp.175-182
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• 2022

In many engineering problems, the dynamic substructuring can be useful to analyze complex structures which made with many substructures, such as aircrafts and automotive vehicles. It was originally intended as a method to simplify the engineering problem. The powerful advantage to this is that computational efficiency dramatically increases with eliminating unnecessary degrees-of-freedom of the system and the system targets are concurrently satisfied. Craig-Bampton method has been widely used for the linear system reduction. Recently, multi-level optimization (such as target cascading), which propagates the system-level targets to the subsystem-level targets, has been widely utilized. To this concept, the genetic algorithm which one of the global optimization technique has been utilized to the substructure optimization. The number of internal modes for each substructure can be obtained by the genetic algorithm. Simultaneously, the reduced system meets the top-level targets. In this paper, various numerical examples are tested to verify this concept.

• 건축구조
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• v.11 no.2
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• pp.23-29
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• 2004

우리회는 한국기술사회건축구조분회로 출발하여 2년 전 유병억 회장님시절 개인사업자등록증을 발급받아 구조분회가 아닌 개인 사업체로서 한걸음 진일보하였다가 작년에야 비로서 우리의 숙원이었던 과학기술부 산하 사단법인체로 등록되면서 명실공히 사단법인 한국건축구조기술사회로 위상을 한단계 격상함으로서 합법적으로 정부로부터 인가받은 단체로 발돋음하였다. 그동안 건축구조안전에 대한 문제점을 알고 있었으나, 정부와의 어떠한 합법적이고 독립적인 통로가 없어 제대로된 의견개진을 할 수 없었던 상황에서 이제는 올바른 통로를 확보한 첫 걸음이라고 판단된다. 아직도 우리가 헤쳐나아가야 할 길은 멀고도 험난한 상황임을 잊지말고 끈기있는 인내심과 중단없는 전진을 통해 하나씩 건축물의 구조안전을 확보하기 위한 방안을 위해 지속적으로 노력을 하였으면 한다. 올해 2월 정기총회를 통해 사단법인으로 처음 출발하면서 이동헌회장님을 비롯한 신임회장단이 선출되었고, 그 장도의 첫발을 내딛으면서 앞으로 우리가 어떤 목표를 견지하여야 할 것인가에 대해 의식고취 및 앞으로의 방향설정을 위해 지난해 3월 건설교통부에서 발족한 건설교통안전기획단의 검토 내용에서 발췌한 현행 실태와 문제점 및 대책 중에서 건축물의 구조안전과 관련된 문제점을 다시 한번 되새기면서 우리의 목표와 방향을 점검하는 계기가 되었으면 한다.