• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.7 s.250
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• pp.787-793
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• 2006

Recently kriging model has been widely used in the DACE (Design and Analysis of Computer Experiment) because of prominent predictability of nonlinear response. Since DACE has no random or measurement errors contrast to physical experiment, space filling experimental design that distributes uniformly design points over whole design space should be employed as a sampling method. In this paper, we examine the maximum entropy experimental design that reveals the space filling strategy in which defines the maximum entropy based on Gaussian or exponential. The influence of these two correlation functions on space filling design and their model parameters are investigated. Based on the exploration of numerous numerical tests, enhanced maximum entropy design based on exponential correlation function is suggested.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.04a
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• pp.465-474
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• 2001

Base Isolation system is an effective design strategy that provides a practical substitute for the seismic design of bridge. In this study, the dynamic tests was performed on HDB (Hysteretic Damping Bearing) and Dynapot. Then, the dynamic analysis was carried out for a bridge using the experimental results to estimate the seismic performance of bearings. Analysis for bridge was performed for four types of earthquake loadings. The result of dynamic test and theoretical analysis indicate that the performance of HDB and Dynapot is appropriate for the earthquake loading.

• Corrosion Science and Technology
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• v.20 no.2
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• pp.52-61
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• 2021

This study using experimental design and linear regression technique was implemented in order to predict the pitting potential of stainless steel in marine environments, with the target materials being AL-6XN and STS 316L. The various variables (inputs) which affect stainless steel's pitting potential included the pitting resistance equivalent number (PRNE), temperature, pH, Cl^- concentration, sulfate levels, and nitrate levels. Among them, significant factors affecting pitting potential were chosen through an experimental design method (screening design, full factor design, analysis of variance). The potentiodynamic polarization test was performed based on the experimental design, including significant factor levels. From these testing methods, a total 32 polarization curves were obtained, which were used as training data for the linear regression model. As a result of the model's validation, it showed an acceptable prediction performance, which was statistically significant within the 95% confidence level. The linear regression model based on the full factorial design and ANOVA also showed a high confidence level in the prediction of pitting potential. This study confirmed the possibility to predict the pitting potential of stainless steel according to various variables used with experimental linear regression design.

• Korean Journal of Computational Design and Engineering
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• v.10 no.3
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• pp.217-223
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• 2005

Tight integration between design and analysis processes and the data representation in the ship design application domain have been studied in this paper. Multi-Representation Architecture for design and analysis integration, proposed at Georgia Institute of Technology, has been carefully investigated for the application in the initial ship design stage. The MRA approach facilitates efficient generation of analysis models from the initial ship design data, thus reducing design lead time. Easy generation of analysis model is important because it allows quick analysis iteration under frequent design changes. The SMM, ABB and PBAM are defined for the analysis model of the typical ship structure. Only a part of the typical initial ship design data has been considered in the experimental implementation of the proposed approach. However, the prototype implementation shows that the application of MRA approach in the structural ship design domain is quite feasible. It is also contemplated that the same approach can be extended for other design and analysis views in the ship design domain.

• Journal of computational fluids engineering
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• v.8 no.3
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• pp.32-40
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• 2003

CFD analyses of the three-dimensional turbulent flow in the impeller and diffuser of an axial flow pump including suction and discharge parts are presented and compared with experimental data. The purpose of the current study is to validate the CFD method for the performance analysis of the main coolant pump for SMART and to investigate the effect of suction and discharge shapes on the pump performance. To generate a performance curve, not only the design point but also the off-design points were computed. The results were compared with available experimental data in terms of head generated. At the design point, the analysis accurately predicts the experimental head value. In the range of the higher flow rates, the results are also in very good agreement with the experimental data, in magnitude but also in terms of slope of variation. For lower flow rates, the results shows that the analysis considering the suction and discharge well describe the typical S-shape performance curve of the axial pump.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.10
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• pp.137-146
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• 2004

This is the second of two companion papers concerned with the analysis and design of a pneumatic vibration isolation system. The properties of the system are clarified by observation of the transmissibility surface calculated by the models and algorithm developed in the first paper of this research. It Is shown that the nonlinear model proposed in this research is more closer to experimental results than the linear model that have been used in previous studies. The design optimization of the major design variables that affect the performance of the system is achieved by using the condition for attenuation, disturbance rejection and maximum damping in resonance peak. The design space search method is adopted for the optimization of the orifice area. The models, transmissibility calculation algorithms and design optimization techniques developed in this research are shown to be greatly helpful to the optimal design of the pneumatic vibration isolation system by experiment.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.2
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• pp.181-192
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• 2005

This study evaluated the effect of factors influencing the initial biofilm formation in drinking water distribution pipe by running experiments using a $2^{4-1}$ fractional factorial experimental design with a replicate. Important variables used for assessing biofilm formation included BDOC(biodegradable dissolved organic carbon), viable heterotrophic bacteria present in drinking water, water temperature, and shear stress at two levels each. Based on the statistical analysis of biofilm levels measured as attached HPC(heterotrophic plate count) and community-level assay, the main factors that have significant effects on biofilm formation were found to be viable heterotrophic bacteria and BDOC. Water temperature only exhibited significant effect on the levels of attached HPC, while shear stress was not a significant factor under given conditions. Moreover, the statistical analysis revealed that interactions between the important variables were not statistically significant at a 0.05 significance level.

• Proceedings of the Safety Management and Science Conference
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• 2011.04a
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• pp.95-99
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• 2011

The research analyzes structure models of Repeated Measurement Design (RMD) and Hierarchical Design (HD). The experimental unit of RMD model is living organisms, such as human. In contrast, HD is used when all the factors are random. The HD models are derived from R:B:A, R:C:B:A and R:C:($A{\times}B$).

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.4
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• pp.1-6
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• 2003

Steady flow bench test is a practical, powerful and widely used in most engine manufacturers to give a design concept of a new engine. In order to use steady data as a performance index, it is necessary to build some database, which can correlate the port characteristics with engine data. However, it is very difficult to investigate all port shapes with experimental tools. The steady flow scheme is relatively simple and its results are bulk ones such as flow rate and momentum of flow. Therefore a CFD code can be easily applied to the port evaluation. In this study, the steady flow test was simulated through three-dimensional analysis on intake port design for comparing with experimental data and confirming the feasibility of applying analytic method . for this purpose, the effect of valve curvature on flow rate was estimated by a CFD code. Numerical results were compared with those of real steady flow tests. As a result, the results of 3-D analysis were almost consistent with experimental data.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.852-857
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• 2004

A new and efficient method for estimating the statistical moments of a system performance function has been developed. The method consists of two steps: (1) An approximate response surface is generated by a quadratic regression model, and (2) the statistical moments of the regression model are then calculated by experimental design techniques proposed by Seo and $Kwak^{(4)}$. In this approach, the size of experimental region affects the accuracy of the statistical moments. Therefore, the region size should be selected suitably. The D-optimal design and the central composite design are adopted over the selected experimental region for the regression model. Finally, the Pearson system is adopted to decide the distribution type of the system performance function and to analyze structural reliability.