• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.527-530
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• 1997

An automated process planning system for cold forging of non-axisymmetric parts of comparatively simple shape was developed in this study. Programs for the system have been written with Visual LISP in the AutoCAD using a personal computer and are composed of four main modules such as input module, shape cognition and shape expression module, material diameter determination module and process planning module. The design rules and knowledges for th system are extracted from the plasticity theories. handbook, relevant reference and empirical knowledge of field experts. Generally, in forging, only front view is needed for expression of axisymmetric parts, but non-axisymmetric parts are needed both front view and plane. At the plane, this system cognizes the external shape of non-axisymmetric parts - number of sides of regular polygon and radius of a circle circumscribing the polygon of n sides. At the front view, the system perceives diameter of axisymmetric portions and hight of primitive geometries such as polygon, cylinder, cone, concave, convex, etc.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.9
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• pp.1117-1125
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• 2013

A finite element based approach that can be used to investigate the plane-view shape and crop loss of a material during plate rolling is presented. We employed a three-dimensional finite element model to continuously simulate the shape change of the head and tail of a plate as the number of rolling passes increases. The main feature of the proposed model lies in the fact that the multistage rolling can be simulated without a break because the rolling direction of the material is reversibly controlled as the roll gap sequentially decreases. The material constants required in the finite element analysis were experimentally obtained by hot tensile tests. We also performed a pilot hot plate rolling test to verify the usefulness of the proposed finite element model. Results reveal that the computed plane-view shapes as well as crop losses by the proposed finite element model were in good agreement with the measured ones. The crop losses predicted by the proposed model were within 5% of those measured from the pilot hot plate rolling test.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.2
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• pp.195-202
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• 2002

An automated process planning system for cold forging of non-axisymmetric parts of comparatively simple shape was developed in this study. Programs for the system have been written with Visual LISP in the AutoCAD using a personal computer and are composed of four main modules such as input module, shape cognition and shape expression module, material diameter determination module and process planning module. The design rules and knowledges for the system are extracted from the plasticity theories, handbook, relevant reference and empirical knowledge of field experts. Generally, in forging, only front view is needed for expression of axisymmetric parts, but non-axisymmetric parts need front and plane view. At the plane, this system cognizes the external shape of non-axisymmetric, parts - number of sides of regular polygon and radius of a circle circumscribing the polygon of n sides. At the front view, the system perceives diameter of axisymmetric portions and height of primitive geometries such as polygon, cylinder, cone, concave, convex, etc.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1303-1308
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• 2008

This paper presents effects of impeller geometrical parameters on the performance of a centrifugal pump impeller. The effects of meridional parameters and vane plane development parameters on the performance of the impeller were numerically studied using a commercial CFD code and DOE(design of experiments) software. Geometrical parameters in a method of meridional view and vane plane development were selected and defined to generate the 3D impeller shape. The response variables are defined in a total head and efficiency curve with flow rate. The influences of selected design variables on the various objective functions were examined as a result of the calculation using 2k factorial.

• Transactions of Materials Processing
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• v.11 no.5
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• pp.405-413
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• 2002

A process planning system for cold forging of non-axisymmetric parts of comparatively simple shape was developed in this study. Programs for the system have been written with Visual LISP in AutoCAD. Shape of the product must be drawn with the solid line and the hidden line, and with the plane and front view, as well. At the plane, the system recognizes the external shape of non-axisymmetric portions - the number of the sides of the regular polygons and the radii of circles inscribing and circumscribing the polygon. At the front view, the system cognizes the diameter of axisymmetric portions and the height of the primitive geometries such as polygon, cylinder, cone, concave, convex, etc. The system perceives that the list developed from the solid line must be formed by the operation of forward extrusion or upsetting, and that the list developed from the hidden line must be formed by the operation of backward extrusion. The system designs the intermediate geometries again by considering clearance between workpiece and die, and then finally the billet diameter, in reverse order from the finished product, on the basis of volume constancy and using the operations, the forming sequence, the number of operations and the intermediate geometries which were already designed. The design rules and knowledges for the system were extracted from the plasticity theories, handbook, relevant reference and empirical knowledge of field experts. Suitability of the process planning was analyzed using SuperForge of FVM simulation package. The results of analysis showed good formability.

• The Research Journal of the Costume Culture
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• v.8 no.5
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• pp.668-680
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• 2000

The study presents the general types and individual differences of the shape of the adult women's neck and shoulder in our country. It is based on the average value, the standard deviation, the maximum value, the standard deviation, the maximum value, the minimum value and c.v. measured from the women at the age of 19 through 64. The results of this study are as follows ; 1. The factors by factor analysis are five. The first is the size factors of the neck and shoulder. The second is shape factor of neck. The third is plane view and length factor of the neck. The fourth is the side view factor of the neck and shoulder. The fifth is the shape factor of shoulder. Therefore the shape of the neck and shoulder should be examined in the shape factors as well as in the size factors as well as in the size factors for the designing body-suitable clothes. 2. The factors of the concrete objects are the solid view of neck and shoulder, the cross-sectional view of neck line, side view of neck and shoulder and length of neck. The explainable measuring items for the factors are the difference of the length between lower neck round line and the 4㎝ above neck round line, the length of neck, the angle of inclination between fore neck and back neck, the angle of inclination of the side shoulder, the difference of the height between fore neck point and back neck point, the width of shoulder, the width of chest and the width of back. 3. The concrete objects of the neck and shoulder have five types ; Type Ⅰ is average type, Type Ⅱ is thick short neck and the drooping shoulder type, Type Ⅲ I is slender long neck and lean-back shoulder type, Type Ⅳ is thick and rising shoulder type and Type Ⅴ is slender and drooping shoulder type.

• Journal of the Korean Home Economics Association
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• v.31 no.4
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• pp.209-214
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• 1993

The purpose of this study is to provide the fundamental data for a dummy design used I read-made clothing and underwear production I terms of a pattern of breast types based o their morphological characteristics in accordance with different pattern of breast types. The breast's side and frontal views of the breast were measured with 90 junior high school girls of age between 13 and 16 residing in the urban area of Seoul using the plan photogrammetry. 1. The correlation between the side view body measurement and the breast's side and front view were analyzed by using the canonical correlation analysis, whereby the side view body measurement is showing a 39% of the breast's side view and frontal view. 2. The breast's side and front view has been classified by cluster analysis. The results of custer analysis for the breast's side and front view would be turned out the four cluster. 1) The cluster Ⅰ, The most volumed breast's side view.(20%) 2) The cluster Ⅱ, The fastest growing breast's front view.(38%) 3) The cluster Ⅲ, the latest growing breast.(3%) 4) The cluster Ⅳ, the middle degree growing breast.(39%)

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.04a
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• pp.175-182
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• 1998

The object of this study is shape finding and cutting pattern generation of membrane structures under the following assumptions : (1) material is linearly elastic (2) stress state is plane stress. Cable and membrane structures should introduce the nonlinear analysis considering geometric nonlinearity because these structures deform largely under the external loads. The analysis procedure is consisted of three steps considering geometric nonlinearity unlike any other structures. First step is the shape finding analysis to determine the initial equilibrium shape. Second step is the stress-deformation analysis to investigate the behaviors of structures under various external loads. Once a satisfactory shape has been found, a cutting pattern based on the shape finding analysis may be generated from the view point of construction. In this paper, (1) shape finding analysis formulation and an example, (2) cutting pattern determination procedure using weighted least-square minimization flattening method and some results are presented.

• 한국전산유체공학회:학술대회논문집
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• 1999.11a
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• pp.65-70
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• 1999

Radiative heating of a liquid rocket base plane due to plume emission is numerically investigated. Calculation of flow and temperature fields around rocket nozzle precedes and thereby realistic plume shape and temperature distribution inside the plume are obtained. Based on the calculated temperature field, radiative transfer equation is solved by discrete ordinate method. The averaged radiative heat flux reaching the base plane is about $5kW/m^2$ at the flight altitude of 10.9km. This value is small compared with radiative heat flux caused by constant-temperature (1500K) plume emission, but it is not negligibly small. At higher altitude (29.8km), view factor between the babe plane and the exhaust plume is increased due to the increased expansion angle of the plume. Nevertheless, the radiative heating disappears since the base plane is heated to high temperature (above 1000K) due to convective heat transfer.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.10a
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• pp.266-273
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• 1998

The object of this study is shape finding and cutting pattern generation of membrane structures under the following assumptions: (1) material is linearly elastic (2) stress state is plane stress. Cable and membrane structures should introduce the nonlinear analysis considering geometric nonlinearity because these structures deform largely under the external loads. The analysis procedure is consisted of three steps considering geometric nonlinearity unlike any other structures. First step is the shape finding analysis to determine the initial equilibrium shape. Second step is the stress-deformation analysis to investigate the behaviors of structures under various external loads. Once a satisfactory shape has been found, a cutting pattern based on the shape finding analysis may be generated from the view point of construction. In this paper, after shape finding analysis, cutting pattern determination procedure using weighted least-square minimization flattening method and some results are presented.