• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.05a
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• pp.235-240
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• 2004

This paper deals with the performance analysis of impulse turbine for owe type wave energy conversion device. Numerical analysis was performed using a commercially-available software FLUENT. This parametric study includes the variation of the setting angle of guide vane. Since parametric study at various flaw coefficients requires tremendous amounts of computing time, two-dimensional cascade flaw approximation was employed to find out optimum principal particulars in rather simple manner. Full three-dimensional calculation was also performed for several cases to confirm the validity of two-dimensional approach. Results were compared to other experimental data, for instance Setoguchi et al (2001)'s extensive set of data, and found to be well demonstrating the usefulness of 2-D analysis. Advantages and disadvantages of each method were also evaluated.

• Journal of KIBIM
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• v.8 no.2
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• pp.1-9
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• 2018

Nowadays Building Information Modeling (BIM) is a significant source of sharing project information in the construction industry. This method of sharing the information enhances the project understanding among stakeholders. Modeling of information using BIM is becoming an essential part of many construction projects around the globe. Despite rapid adoption of BIM in construction industry still, some sectors of the industry like earthwork have not yet reaped its full benefits. BIM has brought a paradigm shift through identification and integration of the roles and responsibilities of project participants on a single platform. BIM is a 3D model-based process which provides the insight into the efficient project planning and design. The 3D modeling can also be used significantly for the design of temporary structures in an earthwork project. This paper presents the quantity take-off methodology and parametric modeling technique for creating the temporary structures using 3D BIM process. A case study is conducted to implement the proposed temporary structure family design on a real site project. The study presented is beneficial for the earthwork project stakeholders to extract the relevant information using 3D BIM models in a project. It provides an opportunity to calculate the quantity of material required for a project accurately.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.36 no.4
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• pp.259-264
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• 2023

In this study, we devised a parametric analysis workflow for efficiently analyzing the material properties of 3D woven materials. The parametric model uses wire spacing in the woven materials as a design parameter; we generated 2,500 numerical models with various combinations of these design parameters. Using MATLAB and ANSYS software, we obtained various material properties, such as bulk modulus, thermal conductivity, and fluid permeability of the woven materials, through a parametric batch analysis. We then used this large dataset of material properties to perform a regression analysis to validate the relationship between design variables and material properties, as well as the accuracy of numerical analysis. Furthermore, we constructed an artificial neural network capable of predicting the material properties of 3D woven materials on the basis of the obtained material database. The trained network can accurately estimate the material properties of the woven materials with arbitrary design parameters, without the need for numerical analyses.

• Journal of the Korea Fashion and Costume Design Association
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• v.21 no.2
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• pp.109-122
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• 2019

The purpose of this study is to examine the clothing component information and attributes as the control parameters for the 3D modeling process of the biomorphic clothing sculpture using a parametric methodology. The 3D modeling parameters of biomorphic clothing sculpture were identified as exaggerated silhouette, surface texture, and digital color. The types of exaggerated silhouettes were shoulder and hip exaggeration, shoulder exaggeration, hip exaggeration, vertical exaggeration, and horizontal exaggeration. The types of surface texture were embossed, lacy, furry, and complex textures. The types of digital color were chrome, blur, blend, and acid colors. The characteristics of morphological representation due to the attributes of these control variables were identified as morphological variation, organic morphology, organizational morphology, and realistic morphology. As a result, it was found that the parameter attributes were applied to the biomorphic clothing sculpture parametric design process and developed into various shapes.

• Korean Journal of Computational Design and Engineering
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• v.14 no.5
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• pp.306-313
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• 2009

This paper presents the unique formation process of a volumetric space with the digital algorithm developed for Voronoi diagram in order to generate an effective parametric architectural form. By applying systematic parameters of architectural conditions within digital parametric tools, the interactions among sub-spaces developed by Voronoi diagram are enhanced by manipulating the spatial structures. In this paper, we discuss how the parametric distributing and zoning geometrical system can support designers in developing a free-formed space, and research on how this system creates a 3D volumetric space. With the in-depth research on the system and structure of Voronoi diagram, the approaches to the application of Voronoi diagram into architectural form generation are clarified to be an effective, creative and successful digital tool. The result of the application of the Voronoi diagram improves the design quality with systematic language in the sense that the sub-regions are created and controlled under the systematic and balanced hierarchy having dynamic relationships among each others with the restoration of the equilibrium of forces and tensions. This 3-dimensional Voronoi diagram provides another means for designers to solve architectural issues and to reinforce their design concepts.

• Proceedings of the Acoustical Society of Korea Conference
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• 1987.11a
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• pp.17-19
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• 1987

In this paper an ultrasonic loud speaker (ie,. parametric speaker) driving technic was proposed. The study was focused on reduction of distortion in self-demodulated sound using a sound source deriven by MDSB(Modified Double Side Band) signal. And, the esperiment was performed in acoustic wave guide usin the developed MDSB unit according to the variation of distance from the source. In the result, prposed MDSB method was found to decrease second harnonic distortion in -3 to -6 dB compared to conventional DSB method.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.4
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• pp.92-98
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• 2010

Virtual ground modeling is one of key topic for real-time vehicle dynamic simulation. This paper discusses about the virtual 3D road modeling process using parametric surface concept. General road data is a type of lumped position vector so interpolation process is required to compute contact of internal surface. The parametric surface has continuity and linearity within boundaries and functions are very simple to find out contact point. In this paper, the parametric surface formula is adopted to road modeling to calculate road hight. Position indexing method is proposed to reduce memory size and resource possession, and a simple mathematical method for contact patch searching is also proposed. The developed road process program is tested in dynamic driving simulation on off-road. Conclusively, the new virtual road program shows high performance of road hight computation in vast field of off-road simulation.

• Journal of Hydrogen and New Energy
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• v.31 no.4
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• pp.387-394
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• 2020

A parametric study of a 2.5 kW class propeller type micro hydraulic turbine was performed. In order to analyze the internal flow characteristics in the hydraulic turbine, three dimensional Reynolds-averaged Navier-Stokes equations with shear stress transport turbulence model were used and the hexahedral grid system was used to construct computational domain. To secure the reliability of the numerical analysis, the grid dependency test was performed using the grid convergence index method based on the Richardson extrapolation, and the grid dependency was removed when about 1.7 million nodes were used. For the parametric study, the axial distance at shroud span (L) between the inlet guide vane and the runner, and the inlet and outlet blade angles (β₁, β₂) of the runner were selected as the geometric parameters. The inlet and outlet angles of the runner were defined in the 3 spans from the hub to tip, and a total of 7 geometric parameters were investigated. It was confirmed that the outlet angles of the runner had the most sensitive effect on the power and efficiency of the micro hydraulic turbine.

• 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.

• Journal of the Korean Geotechnical Society
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• v.32 no.9
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• pp.51-62
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• 2016

Parametric studies for various site conditions by using 3d numerical model were carried out in order to estimate dynamic behavior of soil-pile-structure system in dry soil deposits. Proposed model was analyzed in time domain using FLAC3D which is commercial finite difference code to properly simulate nonlinear response of soil under strong earthquake. Mohr-Coulomb criterion was adopted as soil constitutive model. Soil nonlinearity was considered by adopting the hysteretic damping model, and an interface model which can simulate separation and slip between soil and pile was adopted. Simplified continuum modeling was used as boundary condition to reduce analysis time. Also, initial shear modulus and yield depth were appropriately determined for accurate simulation of system's nonlinear behavior. Parametric study was performed by varying weight of superstructure, pile length, pile head fixity, soil relative density with proposed numerical model. From the results of parametric study, it is identified that inertial force induced by superstructure is dominant on dynamic behavior of soil-pile-structure system and effect of kinematic force induced by soil movement was relatively small. Difference in dynamic behavior according to the pile length and pile head fixity was also numerically investigated.