• Journal of the Korean Society of Safety
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• v.35 no.3
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• pp.32-42
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• 2020

In this study, in order to secure the necessity of introducing the safety certification system for the assembled temporary equipment and materials, the feasibility of the introduction was analyzed through literature review, structural analysis, and actual experiments and surveys related to the assembled temporary equipment and materials. In the previous studies, it was found that the research on the assembled temporary equipment and materials was insufficient, and it was possible to grasp the necessity of introducing the safety certification system for the assembled temporary equipment and materials. In addition, in the results of the serious accident analysis, it was found that the soundness of the temporary equipment and materials is determined by the structural characteristics after it was assembled. As a result of the feasibility analysis of the introduction of the safety certification of the assembled temporary equipment and materials through structural analysis, it is possible to effectively and rationally reflect the main geometrical influence factors, and to introduce the safety certification system that can test the procedures and procedures of the assembled temporary equipment and materials and based on it. It was found that there is a need. As a result of feasibility analysis on the necessity of introducing the safety certification system for assembled temporary equipment and materials through actual experiments, the existing single member performance evaluation has limitations in evaluating the structural performance of the assembled temporary equipment and materials. It was found that there is a need to introduce a safety certification system. As a result of gathering opinions on the feasibility of introducing the safety certification system for assembled temporary equipment and materials of manufacturers and users through the survey, it was found that the overall positive response result was high and the effectiveness was high.

• Earthquakes and Structures
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• v.19 no.4
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• pp.261-272
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• 2020

Recent severe earthquakes in and around the vital public places worldwide indicate the severe vulnerability of ground excitation to be assailed. Reducing the effect of seismic lateral load in structural design is an important conception. Essentially, seismic isolation is required to shield the superstructure in such a way that the building superstructure would not move when the ground is shaking. This study explores the effectiveness, design, and practical feasibility of base isolation systems to reduce seismic demands on buildings of varying elevations. Thus, static and dynamic analyses were conducted based on site-specific bi-directional earthquakes for base-isolated as well as fixed-based buildings. Remarkably, it was discovered that isolators used in low-rise to high-rise structures tend to significantly decrease the structural responses of seismic prone buildings. The higher allowable horizontal displacement induces structural flexibility and ensure good structural health of the building stories. Reinforcement from vertical and horizontal members can be reduced in significant amounts for BI buildings. Thus, although incorporating base isolators increases the initial outlay, it considerably diminishes the total structural cost.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2000.04b
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• pp.168-173
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• 2000

Design of experiments is utilized for exploring the design space and for building response surface models in order to facilitate the effective solution of multi-objective optimization problems. Response surface models provide an efficient means to rapidly model the trade-off among many conflicting goals. In robust design, it is important not only to achieve robust design objectives but also to maintain the robustness of design feasibility under the effects of variations, called uncertainties. However, the evaluation of feasibility robustness often needs a computationally intensive process. To reduce the computational burden associated with the probabilistic feasibility evaluation, the first-order Taylor series expansions are used to derive individual mean and variance of constraints. For robust design applications, these constraint response surface models are used efficiently and effectively to calculate variances of constraints due to uncertainties. Robust optimization of automotive seat is used to illustrate the approach.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.549-556
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• 2006

Life cycle cost is one of important factors in the evaluation of economy feasibility. Load carrying capacity curves for girders and decks are derived on the basis of bridge diagnostic results and condition grade curves to determine the service life and life cycle profile. The total life cycle costs including initial cost, damage cost, maintenance cost, user cost, and etc for the service life are calculated for steel box girder, PSC-I girder and rationalized plate girder. The optimal designs are performed for various service lifes and different superstructure types. The effects of parameters on the life cycle cost are investigated and the economy feasibility is evaluated through the sensitivity analysis.

• Structural Engineering and Mechanics
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• v.54 no.2
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• pp.337-362
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• 2015

This paper presents a feasibility study on structural damage alarming and localization of long-span cable-supported bridges using multi-novelty indices formulated by monitoring-derived modal parameters. The proposed method which requires neither structural model nor damage model is applicable to structures of arbitrary complexity. With the intention to enhance the tolerance to measurement noise/uncertainty and the sensitivity to structural damage, an improved novelty index is formulated in terms of auto-associative neural networks (ANNs) where the output vector is designated to differ from the input vector while the training of the ANNs needs only the measured modal properties of the intact structure under in-service conditions. After validating the enhanced capability of the improved novelty index for structural damage alarming over the commonly configured novelty index, the performance of the improved novelty index for damage occurrence detection of large-scale bridges is examined through numerical simulation studies of the suspension Tsing Ma Bridge (TMB) and the cable-stayed Ting Kau Bridge (TKB) incurred with different types of structural damage. Then the improved novelty index is extended to formulate multi-novelty indices in terms of the measured modal frequencies and incomplete modeshape components for damage region identification. The capability of the formulated multi-novelty indices for damage region identification is also examined through numerical simulations of the TMB and TKB.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.54-58
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• 2008

The structural intensities have been applied to understand a source point and the path of vibrational energy flows in interested structures by many researchers. In this paper, a feasibility study was carried out to investigate the characteristics of a damaged beam with a inflicted open crack using the structural intensities. The damaged beam was taken as a continuous system with equivalent bending stiffness and the flexural vibrations were only considered in numerical simulation and experiments. A four(4)-transducer array was used to measure the flexural vibrations of the beam and the structural intensities were estimated by means of cross spectral density method. As a result, the magnitude changes of the structural intensities could be observed in the vicinity of the damage location and a damage index was newly proposed to identify the damage zone. It has been confirmed that the measurement of the structural intensities was simple and effective method to find out the damage zone.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.141-144
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• 2007

Given a number of training data, a traditional BPN is normally trained by minimizing the absolute difference between target outputs and approximate outputs. When BPN is used as a meta-model for inequality constraint function, approximate optimal solutions are sometimes actually infeasible in a case where they are active at the constraint boundary. The paper describes the development of the efficient BPN based meta-model that enhances the constraint feasibility of approximate optimal solution. The modified BPN based meta-model is obtained by including the decision condition between lower/upper bounds of a constraint and an approximate value. The proposed approach is verified through a simple mathematical function and a ten-bar planar truss problem.

• Smart Structures and Systems
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• v.6 no.7
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• pp.811-833
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• 2010

Vibration control and health monitoring of building structures have been actively investigated in recent years but treated separately according to the primary objective pursued. This paper presents a general approach in the time domain for integrating vibration control and health monitoring of a building structure to accommodate various types of control devices and on-line damage detection. The concept of the time-domain approach for integrated vibration control and health monitoring is first introduced. A parameter identification scheme is then developed to identify structural stiffness parameters and update the structural analytical model. Based on the updated analytical model, vibration control of the building using semi-active friction dampers against earthquake excitation is carried out. By assuming that the building suffers certain damage after extreme event or long service and by using the previously identified original structural parameters, a damage detection scheme is finally proposed and used for damage detection. The feasibility of the proposed approach is demonstrated through detailed numerical examples and extensive parameter studies.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.483-489
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• 2006

This study describes the XML -based digitalization of structural design sheets for exchange on the web. For this purpose the data model of the XML document that represents the structural design sheets for buildings, including mathematical expressions and graphics that cannot be easily exchanged on the web, is defined. Then, the prototype that facilitates the web-based exchange of the XML documents is developed and the feasibility of the results of this study is discussed.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.2
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• pp.163-172
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• 2005

This study aims to evaluate the feasibility of remodeling business by predicting the future price of apartment house after remodeling using Hedonic Price Model. The data concerning such 9 independent variables as location, unit size, unit plan, landscape, parking, the number of elapsed years after completion, number of units, mechanical performance, interior from 25 regions in Seoul metropolitan city were collected and evaluated by established evaluation criteria. The coefficients affecting the price of apartment unit were made by way of linear multi-regression and put into Hedonic Price Model. The feasibility evaluation model for apartment was made and verified by data of remodelled apartment. The predicted results using suggested evaluation model coincide with actual apartment market situations.