• Journal of the Korean Society of Industry Convergence
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• v.8 no.4
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• pp.205-212
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• 2005

This paper presents the application of system identification approaches for the load carrying capacity evaluation of composite PCI girder bridges based on the result of field test. For these problems, the moment of inertia of cross-sectional area and the natural frequency of bridge were used as structural parameters, the SAP2000 program for the structural analysis and the SLP method for the minimum error. As a result, it is found that the proposed algorithm for this study appears applicable to real structures with reasonable complexity. It is shown that the introduction of approximate quadratic equations is more realistic and timesaving than the common methods.

• Structural Engineering and Mechanics
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• v.39 no.3
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• pp.399-410
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• 2011

Base isolation, having quite simple contents, aims to protect the buildings from earthquake-induced damages by installing structural components having low horizontal stiffness between substructure and superstructure. In this study, an appropriate base isolation system for 2-D reinforced concrete frame is investigated. For different structural heights, the structural systems of 2, 3 and 4 bays are modeled by applying base isolation systems and results are compared with conventional structural systems. 1999 Marmara earthquake data is used for applying the model by time history method in SAP2000 package. Results of various parameters such as base shear force, structure drift ratio, structure period and superstructure acceleration are discussed for all models.

• Structural Monitoring and Maintenance
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• v.5 no.2
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• pp.173-187
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• 2018

Performance evaluation of RC frame building by nonlinear static pushover analysis that accounts for elastic and post elastic behavior is becoming very popular as a valid decision making tool in seismic hazard resistant designs. Available literature suggests great amount of interest has shown by researchers in suggesting refinements to geometric and material modelling to bridge the gap between analytical predictions and observed performances. Notwithstanding the attempts gaps still exists. Sequence of plastic hinge formation which has great influence on pushover analysis results is an area less investigated. This paper attempts to highlight the importance of hinge sequence considerations to make analysis results more meaningful. Variation in analysis results due to different hinge sequences have been quantified, compared and bounds on analysis results have been presented.

• Journal of Korean Association for Spatial Structures
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• v.2 no.3 s.5
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• pp.115-122
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• 2002

It is often hard to obtain analytical solutions of boundary value problems of shells. Introducing some approximations into the governing equations may allow us to get analytical solutions of boundary value problems. Instead of an analytical procedure, we can apply a numerical method to the governing equations. Since the governing equations of shells of revolution under symmetric load are expressed by ordinary differential equations, a numerical solution of ordinary differential equations is applicable to solve the equations. In this paper, the governing equations of orthotropic spherical shells under symmetric load are derived from the classical theory based on differential geometry, and the analysis is numerically carried out by computer program of Runge-Kutta methods. The numerical results are compared to the solutions of a commercial analysis program, SAP2000, and show good agreement.

• The Plant Pathology Journal
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• v.16 no.1
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• pp.52-54
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• 2000

Pitch canker of Pinus rigida, caused by Fusarium subglutinans f. sp. pini, was first noticed in Inchon, Korea, and is now being spread into other plantations of pines. Typical symptoms re resin flows from canders on the shoots, branches, and trunks, and resin-soaking of the sap wood under the bark. Pathogenic fungi were isolated from the infected shoots, branches, and sees on Fusarium-selective medium. Mycelial growth and microscopic characteristics were examined. Pathogenicity test was carried out by inoculating four common species of pines (P. rigida, P. densiflora, P. thunbergii, and P. koraiensis) in Korea. P. rigida and P. thunbergii showed symptoms identical to those of naturally infected trees, while P. densiflora and P. koraiensis remained free symptomless.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.394.2-394
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• 2002

The differential equations governing free vibrations of the elastic arches with unsymmetric axis are derived in the rectangular coordinates rather than in polar coordinates, in which the effect of rotatory inertia is included. Frequencies and mode shapes are computed numerically for parabolic arches with both clamped ends and both hinged ends. Comparisons of natural frequencies between this study and SAP 2000 are made to validate theories and numerical methods developed herein. (omitted)

• Earthquakes and Structures
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• v.3 no.6
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• pp.853-867
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• 2012

In this paper, a new type of passive energy dissipating system similar to added damping and stiffness (ADAS) and triangular added damping and stiffness (TADAS) is proposed and implemented in the analytical model of a building with hybrid structural system in the structure's base which we call it; Telescopic column. The behavior and performance of a high rise R.C. structure equipped with this system is investigated and compared with conventional base isolation systems such as rubber isolator bearings and friction pendulum bearings. For this purpose a series of ground acceleration records of the San Fernando, Long Beach and Imperial Valley earthquakes are used as the disturbing ground motions in a series of numerical simulations. The nonlinear numerical modeling which includes both material and geometric nonlinearities were carried out by using SAP2000 program. Results show suitable behavior of structures equipped with telescopic columns in controlling the upper stories drifts and accelerations.

• Proceedings of the KSR Conference
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• 2001.10a
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• pp.304-309
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• 2001

Natural frequencies are studied for dynamic analysis of plate girder bridges which are made up about 34% in the existing railway bridges in Korea. In this study, standard plate girder bridges designed by L-22, a standard load type of the railway specification in Korea, are modeled for finite element method analysis. SAP2000n, a commercial finite element method analysis tool, is used for structural analyses and evaluations. Span lengths of Plate girders have 7 types : 6m, 9m, 12m, 15m, 22m, 24m, and 30m. Natural frequencies are considered in mass rations and span lengths and they are compared with a recommendation of UIC 776-1R for alterations, from now on, in train conditions of operation. For changes of natural frequencies in plate girders by damages of structures, Parameter studies are accomplished.

• Proceedings of the KSR Conference
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• 2001.10a
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• pp.287-292
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• 2001

Static behaviors of railway plate girder bridges designed by the L-22, a standard load type of the railway specification in Korea, are evaluated by widely eight load cases. The load cases are three real loads, which contain three locomotive types of Saemaul PMC, diesel, and Korea Train Express(KTX), and three design loads, L-22, L-18, and HL-25 loads, in railway specification. Plate girders for analysis have the length of spans of six types：6m, 9m, 12m, 22m, 24m, and 30m. For analysis SAP2000n ,a commercial FEM tool, is used. Dominant axial load types are taken from these results that are maximum deflections, reaction forces, and absolute maximum bending moment in girders.

• Proceedings of the Technology Innovation Conference
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• 2000.06a
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• pp.175-209
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• 2000

The performance of US economy in the last cecade is considered to be driven by the IT investment. However, the causal relationship has not been conclsive between IT investment and economic performance, which makes a decision in IT investment tricky. IT as a growth strategy is critical to the developing countries which experienced resource constraint. In case IT acts as a driving force in the new technology paradigm, the less investment in IT will continue to which the growth gap between countries. When IT dose not make a significant contribution to growth, heavy investment in IT means misallocations of resources. Therfore a decision on IT investment has critical implication in terms of growth strategy. Based on a growth accounting nethod, the current study is to analyse the contribution of IT