• Earthquakes and Structures
• /
• 제13권5호
• /
• pp.497-507
• /
• 2017

Flooding induced scour has been long recognized as a major hazard to river-crossing bridges. Many studies in recent years have attempted to evaluate the effects of scour on the seismic performance of bridges, and probabilistic frameworks are usually adopted. However, direct and straightforward insight about how foundation scour affects bridges as a type of soil-foundation-structure system is usually understated. In this paper, we provide a comprehensive review of applied methods centering around seismic assessment of scoured bridges considering soil-foundation-structure interaction. When introducing these applied analysis and modeling methods, a simple bridge model is provided to demonstrate the use of these methods as a case study. Particularly, we propose the use of nonlinear modal pushover analysis as a rapid technique to model scoured bridge systems, and numerical validation and application of this procedure are given using the simple bridge model. All methods reviewed in this paper can serve as baseline components for performing probabilistic vulnerability or risk assessment for any river-crossing bridge system subject to flood-induced scour and earthquakes.

• Structural Engineering and Mechanics
• /
• 제68권6호
• /
• pp.647-660
• /
• 2018

The Incremental Dynamic Analysis (IDA) procedure is currently known as a robust tool for estimation of seismic collapse capacity. However, the procedure is time-consuming and requires significant computational efforts. Recently some simplified methods have been developed for rapid estimation of seismic collapse capacity using pushover analysis. However, a comparative review and assessment of these methods is necessary to point out their relative advantages and shortcomings, and to pave the way for their practical use. In this paper, four simplified pushover analysis-based methods are selected and applied on four regular RC intermediate moment-resisting frames with 3, 6, 9 and 12 stories. The accuracy and performance of the different simplified methods in estimating the median seismic collapse capacity are evaluated through comparisons with the results obtained from IDAs. The results show that reliable estimations of the summarized 50% fractile IDA curve are produced using SPO2IDA and MPA-based IDA methods; however, the accuracy of the results for 16% and 84% fractiles is relatively low. The method proposed by Shafei et al. appears to be the most simple and straightforward method which gives rise to good estimates of the median sidesway collapse capacity with minimum computational efforts.

• 대한간호학회지
• /
• 제34권6호
• /
• pp.1004-1013
• /
• 2004

Purpose: The purpose of this paper was to describe the characteristics of smoking prevention programs in Korea, to estimate overall effect size of Korean smoking prevention programs, and to investigate effect size variations by program modality and instruction method. Method: Meta-analysis was performed on2l programs in 20 studies. Result: The estimation of overall effect size for knowledge and attitude was not possible because effect sizes were not homogeneous in this meta-analysis. However, effect sizes of studies that were socially influential programs or active/interactive methods were larger than information-oriented programs or passive/non-interactive methods in the pictures. The effects for behavioral outcomes were generally not as positive and not statistically significant. Q statistics showed that variations among effect sizes within program modality and instruction method classifications were heterogeneous. Conclusion: The results from this meta-analysis support the continued use of socially influential programs and active/interactive methods for smoking prevention programs. Because behavioral effect might be the fundamental objective of smoking prevention programs, the present results indicate that smoking prevention programs should consider adopting more effective programs.

• 한국지능시스템학회:학술대회논문집
• /
• 한국퍼지및지능시스템학회 2003년도 ISIS 2003
• /
• pp.395-398
• /
• 2003

Two component analysis methods based on the fuzzy relational calculus are proposed in the setting of the ordered structure. First component analysis is based on a decomposition of fuzzy relation into fuzzy bases, using gradient method. Second one is a component analysis based on the eigen fuzzy sets of fuzzy relation. Through experiments using the test images extracted from SIDBA and View Sphere Database, the effectiveness of the proposed component analysis methods is confirmed. Furthermore, improvements of the image compression/reconstruction and image retrieval based on ordered structure are also indicated.

• 한국경영과학회지
• /
• 제21권3호
• /
• pp.175-195
• /
• 1996

In conventional analysis methods, data and process are loosely coupled for building information systems. Several object oriented approaches have been proposed to integrate data and process. However, object oriented analysis requires a radical paradigm and thus system analysts find difficulties in generating object models direcctly from end users. To alleviate these difficulties, this paper proposes a methodology for deriving an object model by using structured analysis results. Objects are obtianed primarily from entities in Entity-Relationship Diagram. Methods are obtained through the analysis of the relationship between processes and data stores in Data Flow Diagram Methods are assigned to the objects by using object/process matrices. A real-life case is illustrated to demonstrate the usefulness of the methodology.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2003년도 추계학술대회 논문집(II)
• /
• pp.417-422
• /
• 2003

Rockfall mitigation methods have been widely constructed along railway lines but aren't estimated with any economic analysis methods up to now. Therefore, this study applied a benefit-cost analysis to rockfall mitigation method to determine whether it is indeed an economically efficient construction. The Benefits were estimated based on data collected from disaster history, and included three types of benefits that are originated by reduction of train accident, train delay and rockfall removing cost. The costs included both construction cost and the maintenance cost of the selected method. This analysis could clarify the investment effect of rockfall mitigation method that would be built at rockfall prone slope.

• 한국품질경영학회:학술대회논문집
• /
• 한국품질경영학회 2010년도 춘계학술대회
• /
• pp.402-408
• /
• 2010

Forecasting have qualitative and quantitative methods. Quantitative one analyze macro-economic factors such as the rate of exchange, oil price, interest rate and also predict the micro-economic factors such as sales and demands. Applying various statistical methods depends on the type of data. when data has seasonality and trend, Time Series analysis is proper but when it has casual relation, Regression analysis is good for this. Time Series and Regression can be used together. This study investigate artificial neural networks which is predictive technique for casual relation and try to compare the accuracy of forecasting between regression analysis and artificial neural network.

• 한국세라믹학회지
• /
• 제29권1호
• /
• pp.9-14
• /
• 1992

Some of non-isothermal analysis methods are applied to CaO-MgO-Al2O3-SiO2 glass system to find the kinetics parameters of crystallisation, activation energy, Avrami component and frequency factor. The results using the non-isothermal analysis were compared to that of microstructure experiment. Analysis of the result has enabled to some methods to be to recommend as being the most appropriate equation to use in a glass system. It was shown that in the thermal analysis using the non-isothermal method of Kissinger, Augis-Bennett, Bansal, and Marotta, the calculation of activation energy is not much different, while Avrami component and frequency factor are different from applied each methods.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2000년도 가을 학술발표회 논문집
• /
• pp.135-142
• /
• 2000

A framework alternative to that of classical slope stability analysis is developed, wherein the soil mass is treated as a continuum and in situ soil stresses and strengths are computed accurately using inelastic finite element methods with general constitutive models. Within this framework, two alternative methods of stability analysis are presented. In the first, the strength characteristics of the soil mass are held constant, and the gravitational loading on the slope system is increased until failure is initiated by well-defined mechanisms. In the second approach, the gravity loading on the slope system is held constant, while the strength parameters of the slope mass are gradually decreased until well-defined failure mechanisms developed. Details on the applying both of the proposed methods, and comparisons of their characteristics on a number of solved example problems are presented.

• 한국전산유체공학회지
• /
• 제8권1호
• /
• pp.16-22
• /
• 2003

The present study introduces an architecture for performing efficient numerical analysis by using the Internet and three reconstructing methods of existing numerical analysis codes were presented in order to utilize the architecture. These methods were implemented into a computational fluid dynamics program for solving two-dimensional transient flow problems with free surface. The program was reconstructed with Java technologies and compared with the original one. This study will be a preparation for numerical analysis to participate in web services for engineering.