• Journal of Advanced Marine Engineering and Technology
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• 제22권5호
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• pp.670-679
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• 1998

The solution of hyperbolic equation with wave nature has sharp discontinuties in the medium at the wave front. Difficulties encounted in the numrtical solution of such problem in clude among oth-ers numerical oscillation and the representation of sharp discontinuities with good resolution at the wave front. In this work inviscid Burgers equation and modified heat conduction equation is intro-duced as hyperboic equation. These equations are caculated by numerical methods(explicit method MacCormack method Total Variation Diminishing(TVD) method) along various Courant numbers and numerical solutions are compared with the exact analytic solution. For inviscid Burgers equa-tion TVD method remains stable and produces high resolution at sharp wave front but for modified heat Conduction equation MacCormack method is recommmanded as numerical technique.

• 한국전산유체공학회지
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• 제2권1호
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• pp.84-92
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• 1997

In this paper a new structured grid generation technique is introduced. This new technique utilizes predictor-corrector approach, and is a marching scheme in the global sense as the hyperbolic scheme is. In the predictor step, one layer of grid cells is obtained by using Modified Advancing Front Method which generates a collection of quadrilateral cells simultaneously. In the corrector step, the layer of grid cells that is calculated in the predictor step is adjusted by solving Laplace equations to prevent grid lines from skewing and overlapping in highly curved configurations. It is shown that the resultant algorithm, named a MAP scheme, which combines the Modified Advancing Front Method as a Predictor with an elliptic scheme as a corrector can be used to generate globally smooth and locally near-orthogonal grids for external flow fields even for highly curved configurations. Examples of grid generations for external flow fields about several configurations by use of the present approach are given, and its applicability and flexibility have been demonstrated and discussed.

• 제어로봇시스템학회논문지
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• 제9권10호
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• pp.822-831
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• 2003

A computer-vision based pipe-inspection algorithm is developed. The algorithm uses the modified Hough transformation and a line-scanning approach to identify the edge line and the radius of the pipe image, from which the eccentricity and dimension of the pipe-end is calculated. Line and circle detection was performed using Laplace operator with input image, which are acquired from the front and side cameras. In order to minimize the memory usage and the processing time, a clustering method with the modified Hough transformation is introduced for line detection. The dimension of inner and outer radius of pipe is calculated by the proposed line-scanning method. The method scans several lines along the X and Y axes, calculating the eccentricity of inner and outer circle, by which pipes with wrong end-shape can be classified and removed.

• 한국해양공학회지
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• 제11권2호
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• pp.138-144
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• 1997

This is describes the automatic mesh generation on the ship hull surface. At first ship hull is defined as a cillocation of composite surface patches which satisfy the geometic continuity between adjoining patches by using Gregory surface method. Node points that would be mesh points are ganerated by considering the surface curvature. The triangulation of the node points is by the combination of Ohtsubo's method and Choi's one. After triangulation, shape improvement and quadrilateralization is done with specific criterin. An application to the actual ship and the results are shown.

• 대한수의학회지
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• 제19권1호
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• pp.63-67
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• 1979

In order to investigate modified Hayden test for mastitis test milk Samples from 120 cows (total 470 of quarters) were tested by this method. The tests were performed by different lactation age group, different calving frequency and their total quarters. Comparision of results were made between the modified Hayden method and the California Mastitis Test. The results obtained were as follows: 1. Ratio of results of mastitis test between modified Hayden method and California Mastitis Test was 1.1:1.0. 2. Incidence rate of mastitis in different Lactation age group shown 78.5% in 7 to 9 year group, 50% in 4 to 6 year age group and 37.5% in up to 3 year age group, respectively. 3. Incidence rate of mastitis with calving frequency, were 13.5% in 1 to 2 calving frequency group, 83.3% in 3 to 4 calving frequency group and 63.6% in 5 to 6 calving frequency group respectively. 4. Mastitis ratio between rear quarters and front quaters were 1.7:1.0. 5. It is probable that modified Hayden was more sensitive than the California mastitis test in detecting subclinical and clinical mastitis.

• 소성∙가공
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• 제12권3호
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• pp.194-201
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• 2003

An automatic quadrilateral mesh generator for large deformation finite element analysis such as metal forming simulation was developed. The NURBS interpolation method is used for modeling arbitrary 2-D free surface. This mesh generation technique is the modified paving algorithm, which is an advancing front technique with element-by-element resolving method for paving boundary intersection problem. The mesh density for higher analysis accuracy and less analysis time can be easily controlled with high-density points, maximum and minimum element size. A couple of application to large deformation finite element analysis is given as an example, which shows versatility and applicability of the proposed approach and the developed mesh generator for large deformation finite element analysis.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.99.1-99
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• 2002

In this paper, a computer-vision based pipe-inspection algorithm is developed. The algorithm uses the modified Hough transformation and a line-scanning approach to identify the edge line and radius of the pipe image, from which the eccentricity and dimension of the pipe-end is calculated. Line and circle detection was performed using Laplacian operator with input image which are acquired from the front and side cameras. In order to minimize the memory usage and the processing time, a clustering method with the modified Hough transformation for line detection. The dimension of inner and outer radius of pipe is calculated by proposed line-scanning method. The method scans several lines along t...

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.946-950
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• 2003

In this paper, a computer-vision based pipe shape inspection algorithm is developed. The algorithm uses the modified Hough transformation and a line-scanning approach to identify the edge line and radius of the pipe image, from which the eccentricity and dimension of the pipe-end is calculated. Line and circle detection was performed using Laplace operator with input image, which are acquired from the front and side cameras. In order to minimize the memory usage and the processing time, a clustering method with the modified Hough transformation for line detection. The dimension of inner and outer radius of pipe is calculated by proposed line-scanning method. The method scans several lines along the X and Y axes, calculating the eccentricity of inner and outer circle. by which pipes with wrong end-shape can be classified removed.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.521-525
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• 2002

In this paper, a computer-vision based pipe-inspection algorithm is developed. The algorithm uses the modified Hough transformation and a line-scanning approach to identify the edge line and radius of the pipe image, from which the eccentricity and dimension of the pipe-end is calculated. Line and circle detection was performed using Laplace operator with input image, which are acquired from the front and side cameras. In order to minimize the memory usage and the processing time, a clustering method with the modified Hough transformation for line detection. The dimension of inner and outer radius of pipe is calculated by proposed line-scanning method. The method scans several lines along the X and Y axes, calculating the eccentricity of inner and outer circle, by which pipes with wrong end-shape can be classified removed.

• 디지털산업정보학회논문지
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• 제12권4호
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• pp.107-114
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• 2016

Recently, 3D related technology has become a hot topic for IT. 3D technologies such as 3DTV, Kinect and 3D printers are becoming more and more popular. According to the flow of the times, the goal of this study is that the general public is exposed to 3D technology easily. we have developed a web-based application program that enables 3D modeling of facial front and side photographs using a mobile phone. In order to realize 3D modeling, two photographs (front and side) are photographed with a mobile camera, and ASM (Active Shape Model) and skin binarization technique are used to extract facial height such as nose from facial and side photographs. Three-dimensional coordinates are generated using the face extracted from the front photograph and the face height obtained from the side photograph. Using the 3-D coordinates generated for the standard face model modeled with the standard face as a control point, the face becomes the face of the subject when the RBF (Radial Basis Function) interpolation method is used. Also, in order to cover the face with the modified face model, the control point found in the front photograph is mapped to the texture map coordinate to generate the texture image. Finally, the deformed face model is covered with a texture image, and the 3D modeled image is displayed to the user.