• Journal of the Korean Society for Precision Engineering
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• v.17 no.5
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• pp.76-83
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• 2000

Shape reconstruction is considered as a new technology to be useful and important in many areas such as RPD (Rapid Product Development) and reverse engineering, compared with the conventional design and manufacturing. In shape reconstruction, it becomes possible to reconstruct objects not by their measured shape data but those data extracted from the original shape. The goal of this research is to realize 3D shape construction by showing a possible way to analyze the input image data and reconstruct that original shape. The main 2 steps of the reconstructing process are getting cross-section data from image processing and linking loops between one slice and the next one. And the reconstructed object in this way is compared with the other object using a laser scanner and modelled by an commercial software.

• Journal of the Korean Society for Advanced Composite Structures
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• v.4 no.3
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• pp.1-6
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• 2013

In this study, a shape of connector on seismic reinforced strip, which did not cause any physical damage to concrete column and can repair and reinforcement was decided by using nonlinear finite element analysis. Load displacement was applied on the concrete attached by strip. Stress distribution of connector by extension of concrete were checked. Through stress distribution of this analysis results, the most favorable shape was selected as a shape of the connector.

• Structural Engineering and Mechanics
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• v.39 no.1
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• pp.93-113
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• 2011

The explicit nonlinear dynamic relaxation method (DRM) is applied to the nonlinear geodesic shape finding analysis by introducing fictional tensioned 'strings' along the desired seams with a three or four-node membrane element. A number of results from the numerical example for the nonlinear geodesic shape finding and patterning analysis are obtained by the proposed method to demonstrate the accuracy and efficiency of the developed method. Therefore, the proposed geodesic shape finding algorithm may improve the applicability of a four-node membrane element to membrane structural engineering and design analysis simultaneously for the shape finding, stress, and patterning analysis.

• Journal of Information Processing Systems
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• v.13 no.1
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• pp.114-127
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• 2017

This paper proposes a color image coding algorithm based on shape-adaptive all phase biorthogonal transform (SA-APBT). This algorithm is implemented through four procedures: color space conversion, image segmentation, shape coding, and texture coding. Region-of-interest (ROI) and background area are obtained by image segmentation. Shape coding uses chain code. The texture coding of the ROI is prior to the background area. SA-APBT and uniform quantization are adopted in texture coding. Compared with the color image coding algorithm based on shape-adaptive discrete cosine transform (SA-DCT) at the same bit rates, experimental results on test color images reveal that the objective quality and subjective effects of the reconstructed images using the proposed algorithm are better, especially at low bit rates. Moreover, the complexity of the proposed algorithm is reduced because of uniform quantization.

• Structural Engineering and Mechanics
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• v.71 no.2
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• pp.119-129
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• 2019

Optimum shape and length of laterally loaded piles can be obtained with different optimization techniques. In particular, the Fully Stress Design method (FSD) is an optimality condition that allows to obtain the optimum shape of the pile, while the optimum length can be obtained through a transversality condition at the pile lower end. Using this technique, the structure is analysed by finite elements and shaped through the FSD method by contemporarily checking that the transversality condition is satisfied. In this paper it is noted that laterally loaded piles with optimum shape and length have some peculiar characteristics, depending on the type of cross-section, that allow to design them with simple calculations without using finite element analysis. Some examples illustrating the proposed simplified design method of laterally loaded piles with optimum shape and length are introduced.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.328-331
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• 2001

Shape changes of a workpiece in an Eulerian Finite Element analysis for the steady state. three-roll-stand shape rolling are modelled. Although an Eulerian analysis has many advantages for the steady state rolling problems, it necessitates an assumption about the unknown shape of the control volume. In almost all cases. the assumed control volume does not match the final shape and the control volume should be updated. This update can be accomplished by performing a free surface correction. The final shape of a material point, which has a spherical shape at the inlet, can be also predicted by integrating a deformation gradient along a stream line. Analyses of three-roll-stand shape rolling is in detail examined.

• Structural Engineering and Mechanics
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• v.6 no.2
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• pp.173-183
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• 1998

In the shape design of flexible structures, it is useful to predict the initial shape from the desirable large deformed shapes under some loading conditions. In this paper, we present a numerical procedure of an initial shape determination problem for hyperelastic materials which enables us to calculate an initial shape corresponding to the prescribed deformed shape and boundary condition. The present procedure is based on an Arbitrary Lagrangian-Eulerian (ALE) finite element method for hyperelasticity, in which arbitrary change of shapes in both the initial and deformed states can be treated by considering the variation of geometric mappings in the equilibrium equation. Then the determination problem of the initial shape can be formulated as a nonlinear problem to solve the unknown initial shape for the specified deformed shape that satisfies the equilibrium equation. The present approach can be implemented easily to the finite element method by employing the isoparametric hypothesis. Some basic numerical results are also given to characterize the present procedure.

• Journal of the Semiconductor & Display Technology
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• v.19 no.4
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• pp.59-64
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• 2020

In this paper, we found the solution using data based machine learning regression method to check the pore shape, to solve the problem of the experiment quantity occurring when producing scaffold with the 3d printer. Through experiments, we learned secured each print condition and pore shape. We have produced the scaffold from scaffold pore shape defect prediction model using multiple linear regression method. We predicted scaffold pore shapes of unsecured print condition using the manufactured scaffold pore shape defect prediction model. We randomly selected 20 print conditions from various predicted print conditions. We print scaffold five times under same print condition. We measured the pore shape of scaffold. We compared printed average pore shape with predicted pore shape. We have confirmed the prediction model precision is 99 %.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.680-681
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• 2015

This study develops an algorithm that automatically performs reverse engineering on three-dimensional (3D) sweeping shapes using a user's pre-defined feature templates and 3D point cloud data (PCD) of sweeping shapes. Existing methods extract 3D sweeping shapes by extracting points on a PCD cross section together with the center point in order to perform curve fitting and connect the center points. However, a drawback of existing methods is the difficulty of creating a 3D sweeping shape in which the user's preferred feature center points and parameters are applied. This study extracts shape features from cross-sectional points extracted automatically from the PCD and compared with pre-defined feature templates for similarities, thereby acquiring the most similar template cross-section. Fitting the most similar template cross-section to sweeping shape modeling makes the reverse engineering process automatic.

• Structural Engineering and Mechanics
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• v.70 no.6
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• pp.711-722
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• 2019

Considering stress singularities at point support locations, buckling solutions for plates with arbitrary number of point supports are hard to obtain. Thus, new Hp-Cloud shape functions with Kronecker delta property (HPCK) were developed in the present paper to examine elastic buckling of point-supported thin plates in various shapes. Having the Kronecker delta property, this specific Hp-Cloud shape functions were constructed through selecting particular quantities for influence radii of nodal points as well as proposing appropriate enrichment functions. Since the given quantities for influence radii of nodal points could bring about poor quality of interpolation for plates with sharp corners, the radii were increased and the method of Lagrange multiplier was used for the purpose of applying boundary conditions. To demonstrate the capability of the new Hp-Cloud shape functions in the domain of analyzing plates in different geometry shapes, various test cases were correspondingly investigated and the obtained findings were compared with those available in the related literature. Such results concerning these new Hp-Cloud shape functions revealed a significant consistency with those reported by other researchers.