• Journal of the Computational Structural Engineering Institute of Korea
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• v.31 no.1
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• pp.1-8
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• 2018

The purpose of this study is to implement modeling by applying the parametric technique to the atypical trusses of rigid retractable large space structures. The retractable large space structure requires a lot of time and skill in modeling nonlinear shapes or generating, interpreting, and reviewing many models by alternative. To solve these problems, we introduce firstly parametric modeling tool, secondly, we analyze the connection of atypical three-dimensional trusses of a rigid retractable large-space structure, and finally model it as parametric components of the developed trusses. Therefore, it is a future study to make effective modeling of the openable roof by developing the components that can realize the modeling of the truss classified by the opening and closing method, respectively.

• Herbal Formula Science
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• v.17 no.1
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• pp.75-83
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• 2009

Objective : The purpose of this study is to indicate of problems in statistical analysis method of "The Korean Journal of oriental Medical Prescription" and we will be proposed the useful application of the statistical analysis method. Methods : In this paper, we were analysed statistical analysis methodology from published journal articles "The Korean Journal of Oriental Medical Prescription" December, year 2000 to December, year 2008. We were investigated of problems in application of structured analysis methods those journal articles that including statistical analysis techniques and analysis methods. Results : 1. A random allocation of the experimental group and control groups are important factors in the planning process of statistical analysis. However, there are less explanation those journal articles. 2. There are no consideration in specimen size that there will be considerate by the level of significance and statistical test. 3. Many article authors were confused between parametric methods and non-parametric methods that they were applied parametric statistical analysis methods although inapplicable sample size. 4. There were applied the parametric methods consists of t-test instead non-parametric methods in the comparison of average intergroup relations. 5. There were less understanding posterior analysis and were confused with t-test. Conclusion : Our goal was to outline the key methods with a brief discussion of problems(statistical analysis methods), avenues for solutions. we recommend authors to use an appropriate statistical analysis methods for obtaining a more cautions results.

• 한국전산유체공학회:학술대회논문집
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• 2009.04a
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• pp.191-195
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• 2009

A parametric study for for the water entry of a two dimensional symmetric wedge with deadrise angle of 10 degrees was carried out to find out the most dominant parameter. Water entry problem with constant velocity is simplified as the stationary wedge in the way of the upcoming water surface. The calculated impact loads showed that the effect of the viscosity was not so important in this problem. For a given grid system a suitable time step size can be found. The most sensitive parameter was found to be the grid size.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.9
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• pp.70-76
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• 2003

In this study, the hydraulic breaker system was analyzed and simulated using. The simulation result was certified comparing with the experimental result. From the parametric analysis, the effects of each factor were revealed. Through the simulation with varying parameters, the method to reduce the return line pressure fluctuation was presented.

• 한국연소학회:학술대회논문집
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• 2013.06a
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• pp.13-14
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• 2013

The aim of this study is to investigate the parametric characteristics on regenerative system with oxy-fuel combustion by experiment. Regenerative system with a pair of oxygen burners and regenerators is used for evaluating regenerator characteristics according to design parameters such as ball (regenerator medium) size, regenerator weight, and bypass of exhaust gas. The temperature profiles with time are varied by ball size and regenerator weight. The bypass of exhaust gas shows that the heat recovery ratio increases while the regenerating temperature efficiency slightly decreases.

• Structural Engineering and Mechanics
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• v.74 no.3
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• pp.381-394
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• 2020

The structural performance of cold-formed steel (CFS) built-up battened columns were numerically investigated in this paper. The built-up column sections were formed by connecting two-lipped channels back-to-back, with a regular spacing of battens plates, and have been investigated in the current study. Finite element models were validated with the test results reported by the authors in the companion paper. Using the validated models, the parametric study was extended, covering a wider range of overall slenderness to assess the accuracy of the current design rules in predicting the design strengths of the CFS built-up battened columns. The parameters viz., overall slenderness, different geometries, plate slenderness (b/t ratio) and yield stress were considered for this study. In total, a total of 228 finite element models were analyzed and the results obtained were compared with current design strength predicted by Effective Width Method of AISI Specifications (AISI S100:2016) and European specifications (EN1993-1-3:2006). The parametric study results indicated that the current design rules are limited in predicting the accuracy of the design strengths of CFS built-up battened columns. Therefore, a design equation was proposed for the AISI and EC3 specifications to predict the reliable design strength of the CFS Built-up battened columns and was also verified by the reliability analysis.

• Journal of the Korean Geotechnical Society
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• v.35 no.11
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• pp.15-23
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• 2019

In this study, the displacement of soft clay layer with installed Buttress type Self supporting Composite Wall (BSCW) was investigated using numerical method. The model was validated using the field displacement data at the front center of BSCW and parametric analysis of the model was implemented at varied cohesion, elastic modulus of 3 different clay layers (soft, medium, and stiff). In addition, parametric study was also performed for varied center-to-center distance of bottom cement grouting columns installed by jumbo special pattern (JSP) method. The results of parametric study demonstrated that the displacement of BSCW is the most significant in soft clay layer and low center-to-center distance of grouting columns is required at relatively low elastic modulus of clay layer.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.4
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• pp.413-421
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• 2010

In this study, residual-stress distributions in welds with different strength used in natural gas pipelines are calculated by using finite-element analysis and simulating a realistic welding process. The temperature and residual-stress analysis results are compared with the real fusion profile and the application results of the Fitness-For-Service assessment code, API 579 in order to validate the finite-element analysis model and procedure. Parametric study is performed to assess the effect of welding and material variables such as mechanical strength mismatch, the strength of weld metal, reinforcement, and heat input on the residual stress distributions. Finally, on the basis of the parametric study results, the effects of these variables on residual stress distributions are investigated. In particular, the strength mismatch between base metals has an insignificant effect on residual-stress distributions.

• Geomechanics and Engineering
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• v.29 no.1
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• pp.25-40
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• 2022

In this study, 3D coupled-consolidation numerical parametric study was conducted to predict the deformation mechanism of a 20 storey building sitting on (4×4) piled raft (with length of piles, L_p=30 m) to adjacent 6 m diameter (D) tunnelling in stiff clay. The influences of different tunnel locations relative to piles (i.e., z_t/L_p) were investigated in this parametric study. In first case, the tunnel was excavated near the pile shafts with depth of tunnel axis (z_t) of 9 m (i.e., z_t/L_p). In second and third cases, tunnels were driven at z_t of 30 m and 42 m (i.e., z_t/L_p = 1.0 and 1.4), respectively. An advanced hypoplastic clay model (which is capable of taking small-strain stiffness in account) was adopted to capture soil behaviour. The computed results revealed that tunnelling activity adjacent to a building resting on piled raft caused significant settlement, differential settlement, lateral deflection, angular distortion in the building. In addition, substantial bending moment, shear forces and changes in axial load distribution along pile length were induced. The findings from the parametric study revealed that the building and pile responses significantly influenced by tunnel location relative to pile.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.552-560
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• 2004

Stone column is a soil improvement method and can be applicable for loose sand or weak cohesive soil. Since the lack of sand in Korea, stone column seems one of the most adaptable approach for poor ground as a soil improvement method. However, this method was not studied for practical application. In this paper, the most effective design parameters for the being capacity of stone column were studied. The parametric study of major design factors for single stone column was carried out under the bulging and general shear failure condition, respectively. Especially, a test result of single stone column by static load was compared with the bearing capacity values of suggested formulas. The analysis result showed that the ultimate bearing capacity by the formula was much less than the measured value by the static load test. Especially, the result of the parametric study under general shear failure condition showed that the bearing capacity has apparent difference between each suggested formulas with the variation of the major design parameters. Therefore, the result of this study can be a suggestion which is applicable for the field test and the future research.