• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.891_892
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• 2009

This paper presents the rotor study on the deal with the shape design with a flux barrier to minimize the cogging torque of Interior Permanent Magnet Synchronous Motor(IPMSM). In order to consider the notch effect, the torque characteristics according to the shape of notch is performed and analyzed. From the this results, we found that an optimal location and radius of the notch effectively suppresses the torque pulsation of the IPM drive. The rotor shape design also shows improvement in the average torque

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.05a
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• pp.180-185
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• 2001

The sensitivity method has been applied to find perform shape that results in the desired shape after forging. As a 2D example, initial shape of specimen for the cylinder shape without barrelling after forging has been found. The method is then applied to various shapes of 3D free forging and initial shapes of the corresponding specimens after forging have been found successfully. The sensitivity method is proven to be an effective and accurate tool for the preform design.

• Korean Journal of Computational Design and Engineering
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• v.19 no.2
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• pp.119-128
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• 2014

Computing the natural-looking interpolation of different shapes is a fundamental problem of computer graphics. It is proved by some researchers that such an interpolation can be achieved by pursuing the isometry. In this paper, a novel coordinate system that is invariant under isometries is defined. The coordinate system can easily be converted from the global vertex coordinates. Furthermore, the global coordinates can be efficiently recovered from the new coordinates by simply solving two sparse least-squares problems. Since the proposed coordinate system is invariant under isometries, then transformations such as global rigid trans-formations, articulated posture deformations, or any other isometric deformations, do not change the coordinate values. Therefore, shape interpolation can be done in this framework without being affected by the distortions caused by the isometry.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1483-1486
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• 2003

Injection mold is a manufacturing process used to produce the various parts of complicated shape at a low cost. Many factors such as, section shape, resin and mold temperature, filling time, etc, affect on the quality of injection part during injection molding process. The precent study, was carried out the shrinkage analysis of shoes injection mold to optimize runner shape based on filling and packing pressure with MoldFlow. Taguchi design and analysis of variance are used to optimize injection mold design.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.806-809
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• 2003

In this paper, extracting design information from arbitrary aspherical lens shape in reverse engineering is introduced. Deformation terms and sphere data equation with various variables compose asphere equation. Aspherical lens shape is expressed with complicated polynomial expression that includes deformation terms and sphere data. Deformation term and vertex curvature have direct influence on a geometric shape and an optical characteristics of aspherical lens. Hence, extracting these information mean that design information could be derived and analyzed from shape data of arbitrary aspherical lens. Furthermore, sharing designer's experience and knowledge for aspherical lens design could be expected.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.3
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• pp.50-55
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• 2008

In this paper, we propose a new shape compensation scheme to make up for the difference in groove radius between the formed tools and the machined bearing raceways, which inherently takes place during machining the ball bearing raceways by the turning process using conventional formed tools. The associated conventional methods of the formed tool design and its modification such as a simple depth compensation method and a graphical compensation method are introduced and the latter, which has been known to be the better of the two, is experimentally investigated in detail to reveal its drawback. The algorithm is given and it is applied to develop a formed tool design program. The program developed by the presented approach is successfully applied to design the formed turning tool for the bearing raceways.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.841-846
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• 2006

This paper addresses the method for the shape design sensitivity analysis of the buckling load in the continuous elastic body. The sensitivity formula for critical load is analytically derived and expressed in terms of shape variation, based on the continuum formulation of the stability problem. Though the buckling problem is more efficiently solved by the structural elements such as beam and shell, the elastic solids are considered in this paper because the solid elements can be used in general for any kind of structures whether they are thick or thin. The initial stress and buckling analysis is carried out by the commercial analysis code ANSYS. The sensitivity is computed by using the mathematical package MATLAB using the results of ANSYS. Several problems including straight and curved beams under compressive load, ring under pressure load, thin-walled section are chosen to illustrate the efficiency of the presented method.

• Transactions of Materials Processing
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• v.13 no.1
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• pp.90-101
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• 2004

An inverse mosaic method has been proposed to generate an initial blank shape from the final product shape. Differently from the geometric mapping method, the method can handle triangular patches. However, the generated blank shape is strongly dependent on the order of determination of nodes. In order to compensate the dependency error smoothing technique has been also developed. Although the accuracy has been improved greatly compared with the geometrical mapping method, the method has limitation, due to the no incorporation of plasticity theory. Even though the accuracy of the radius vector method is already proved. the method requires initial guess to start the method. In order to compromise the limitation of the present method and the radius vector method, the method has been connected to the radius vector method. The efficiency of the present optimal blank design method has been verified with some chosen examples.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.8
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• pp.1324-1330
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• 2003

A cylindrical cam with a translating roller follower provides to change the rotational motion of the cam to the translation motion of the follower. It's a very useful mechanism in the automation. But, it's very difficult that the shape is defined accurately. This paper proposes a shape design method of the cylindrical cam with a translation roller follower using the relative velocity method$\^$(9,11-13)/ : The relative velocity method calculates the relative velocity of the follower versus the cam at a center of roller, and then determines a contact point by using the geometric relationships and the kinematical constraints. Finally, we present examples in order to prove the accuracy of the proposed methods.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.10a
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• pp.169-176
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• 2003

In the present study, a shape design optimization scheme in shell structures is implemented based on the integrated framework of geometric modeling and analysis. The common representation of B-spline surface patch is used for geometric modeling. A geometrically-exact shell finite element is implemented. Control points or the surface are employed as design variables. In the computation of shape sensitivity, semi-analytical method is employed. Sequential linear programming is applied to the shape optimization of surfaces. The developed integrated framework should serve as a powerful tool to design and analysis of surfaces.