• Journal of the Korea institute for structural maintenance and inspection
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• v.8 no.3
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• pp.225-233
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• 2004

In this study, the seismic safety of containment building is assessed using response surface method. The structural analyses considering random variables such as load, resistance and analysis by ABAQUS are performed to obtain the structural response. The structural response is represented by polynomial of random variables, and the reliability analysis is performed by Level II method. Drucker-Prager failure criterion is applied as limit state function to take bi-axial stress states into account in the concrete. The lifetime probability of failure is evaluated by considering the lifetime of containment building, the annual occurrence rate of earthquake and the conditional probability of failure. Also the sensitivity analysis on the selection of sampling points is performed to obtain the steady results from response surface method.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.8 no.2
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• pp.76-82
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• 2009

In this papers, Study on the Bonding property and Strength Evaluation in Bonding interface Joints of Dissimilar material using DOE. We found optimal condition that uses experimental design method (Response Surface Analysis, DOE) used temperature, pressure, time on experiment factor. And we could get bonding condition and strength that break and crack do not happen in mechanical processing about united dissimilar material. And progress 3 point bending tests and verified result.

• Environmental Engineering Research
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• v.17 no.2
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• pp.117-122
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• 2012

A central composite design and response surface methodology were applied to investigate the optimum conditions for maximum adsorption capacity in activated alumina as an adsorbent. The optimized conditions were determined for adsorption capacity using variables of flow rate and temperature. It was found that flow rate and temperature greatly influenced the adsorption capacity, as determined by analysis of variance analysis of these variables. Statistical checks indicated that second order polynomial equations were adequate for representing the experimental values. The optimum conditions for adsorption capacity were $0^{\circ}C$ and 2,718 mL/min, with the estimated maximum adsorption capacity of 17.82%. The experimental adsorption capacity was 17.75% under these optimum conditions, which was in agreement with the predicted value of 17.82%.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.1
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• pp.59-65
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• 2019

In this study, optimal design of direct-drive VCMs (Voice Coil Motor) for a missile fin actuator is carried out. The torque performance and the characteristics of the VCM are predicted by commercial electromagnetic analysis software, ANSYS Maxwell. The optimal design is obtained at the minimum and maximum actuating angles where the aerodynamic load acting on the fin is the largest in the operating range. The critical variables of the actuator is designed and the RSM (Response Surface Method) is used for the optimization. The response surface model consists of second-order functions and its experimental points are selected by a central composite design. This design is widely used for fitting a second-order response surface. The adjustment regression coefficients is computed for adequacy checking of the response surface model. Finally, the torque values obtained by the RSM and the ANSYS Maxwell are shown in good agreement.

• Structural Engineering and Mechanics
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• v.56 no.4
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• pp.549-567
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• 2015

A first-order moment method (FORM) reliability analysis is commonly used for structural stability analysis. It requires the values and partial derivatives of the performance to function with respect to the random variables for the design. These calculations can be cumbersome when the performance functions are implicit. A Gaussian process (GP)-based response surface is adopted in this study to approximate the limit state function. By using a trained GP model, a large number of values and partial derivatives of the performance functions can be obtained for conventional reliability analysis with a FORM, thereby reducing the number of stability analysis calculations. This dynamic renewed knowledge source can provide great assistance in improving the predictive capacity of GP during the iterative process, particularly from the view of machine learning. An iterative algorithm is therefore proposed to improve the precision of GP approximation around the design point by constantly adding new design points to the initial training set. Examples are provided to illustrate the GP-based response surface for both structural and non-structural reliability analyses. The results show that the proposed approach is applicable to structural reliability analyses that involve implicit performance functions and structural response evaluations that entail time-consuming finite element analyses.

• Journal of the Korean Society of Safety
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• v.28 no.1
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• pp.158-163
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• 2013

While job stress evaluations are reported in the recent surveys upon the nuclear power plants(NPPs), any significant advance in the types of questionnaires is not currently found. There are limitations to their usefulness as analytic tools for the management of safety resources in NPPs. Data mining(DM) has emerged as one of the key features for data computing and analysis to conduct a survey analysis. There are still limitations to its capability such as dimensionality associated with many survey questions and quality of information. Even though some survey methods may have significant advantages, often these methods do not provide enough evidence of causal relationships and the statistical inferences among a large number of input factors and responses. In order to address these limitations on the data computing and analysis capabilities, we propose an advanced procedure of survey analysis incorporating the DM method into a statistical analysis. The DM method can reduce dimensionality of risk factors, but DM method may not discuss the robustness of solutions, either by considering data preprocesses for outliers and missing values, or by considering uncontrollable noise factors. We propose three steps to address these limitations. The first step shows data mining with response surface method(RSM), to deal with specific situations by creating a new method called response surface data mining(RSDM). The second step follows the RSDM with detailed statistical relationships between the risk factors and the response of interest, and shows the demonstration the proposed RSDM can effectively find significant physical, psycho-social, and environmental risk factors by reducing the dimensionality with the process providing detailed statistical inferences. The final step suggest a robust stress management system which effectively manage job stress of the workers in NPPs as a part of a safety resource management using the surrogate variable concept.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.743-748
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• 1996

In this study a method for a robust design of mechanisms is proposed. The method used in the experimental anlysis and quqlity engineering is applied for mechanisms design. A mathematical model for a mechanism is estimated by the responese surface analysis and the robust design can be carried out. The method can be applied for mechanisms generally. Furthermore because the method can be used in the design stage using the computer model, improved quality and lower cost of the product is achieved even in the design stage.

• Geomechanics and Engineering
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• v.4 no.1
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• pp.1-18
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• 2012

The spatial variation of ground motion in Kolkata Metropolitan District (KMD) has been estimated by generating synthetic ground motion considering the point source model coupled with site response analysis. The most vulnerable source was identified from regional seismotectonic map for an area of about 350 km radius around Kolkata. The rock level acceleration time histories at 121 borehole locations in Kolkata for the vulnerable source, Eocene Hinge Zone, due to maximum credible earthquake (MCE) moment magnitude 6.2 were generated by synthetic ground motion model. Soil investigation data of 121 boreholes were collected from the report of Soil Data Bank Project, Jadavpur University, Kolkata. Surface level ground motion parameters were determined using SHAKE2000 software. The results are presented in the form of peak ground acceleration (PGA) at rock level and ground surface, amplification factor, and the response spectra at the ground surface for frequency 1.5 Hz, 3 Hz, 5 Hz and 10 Hz and 5% damping ratio. Site response study shows higher PGA in comparison with rock level acceleration. Maximum amplification in some portion in KMD area is found to be as high as 3.0 times compared to rock level.

• Journal of the Korean institute of surface engineering
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• v.40 no.4
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• pp.185-189
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• 2007

A scanning electron microscope (SEM) is a complex system, consisting of many sophisticated components. For a systematic characterization, a $2^4$ full factorial experiment was conducted. The SEM components examined include condenser lens 1 and 2 (denoted as A and B, respectively), and Objective lens (coarse and fine-denoted as C and D respectively). A statistical analysis was conduced to investigate factor effects and variations In response surfaces. Among four factors, main effect analysis revealed that A and D were Identified as the dominant factor. Moreover, B showed conflicting effect against C. The $R^2$ of statistical regression model constructed was about 69.6%. The model generated 3D response surface plots facilitated understanding of complex tactor effects.

• Structural Engineering and Mechanics
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• v.73 no.5
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• pp.599-612
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• 2020

A combination of a gravity wall and an anchor beam is widely used to support the high soil deposit on rock mass. In this study, two groups of shaking table test were performed to investigate the responses of such combined retaining structure, where the rock masses were shaped with a flat surface and a curved surface, respectively. Meanwhile, the dynamic numerical analysis was carried out for a comparison or an extensive study. The results were studied and compared between the combined retaining structures with different shaped rock masses with regard to the acceleration response, the earth pressure response, and the axial anchor force. The acceleration response is not significantly influenced by the surface shape of rock mass. The earth pressure response on the combined retaining structure with a flat rock surface is more intensive than the one with a curved rock surface. The anchor force is significantly enlarged by seismic excitation with a main earthquake-induced increment at the first intensive pulse of Wenchuan motion. The value of anchor force in the combined retaining structure with a flat rock surface is generally larger than the one with a curved rock surface. Generally, the combined retaining structure with a curved rock surface presents a better seismic performance.