• Geomechanics and Engineering
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• v.15 no.3
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• pp.811-822
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• 2018

Chip size distribution can be used to evaluate the cutting efficiency and to characterize the cutting behavior of rock during cutting and fragmentation process. In this study, a series of linear cutting tests was performed to investigate the effect of cutting conditions (specifically cut spacing and penetration depth) on the production and size distribution of rock chips. Linyi sandstone from China was used in the linear cutting tests. After each run of linear cutting machine test, the rock chips were collected and their size distribution was analyzed using a sieving test and image processing. Image processing can rapidly and cost-effectively provide useful information of size distribution. Rosin-Rammer distribution pamameters, the coarseness index and the coefficients of uniformity and curvature were determined by image processing for different cutting conditions. The size of the rock chips was greatest at the optimum cut spacing, and the size distribution parameters were highly correlated with cutter forces and specific energy.

• Journal of Korea Multimedia Society
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• v.8 no.1
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• pp.34-45
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• 2005

In this paper, a novel implementation of a person verification system based on depth-weighted Hausdorff distance (DWHD) using the surface curvature of the face is proposed. The definition of Hausdorff distance is a measure of the correspondence of two point sets. The approach works by finding the nose tip that has a protrusion shape on the face. In feature recognition of 3D face image, one has to take into consideration the orientated frontal posture to normalize after extracting face area from original image. The binary images are extracted by using the threshold values for the curvature value of surface for the person which has differential depth and surface characteristic information. The proposed DWHD measure for comparing two pixel sets were used, because it is simple and robust. In the experimental results, the minimum curvature which has low pixel distribution achieves recognition rate of 98% among the proposed methods.

• Korea-Australia Rheology Journal
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• v.14 no.3
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• pp.107-114
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• 2002

Residual stress distribution in injection molded short fiber composites is determined by using the layer-removal method. Polystyrene is mixed with carbon fibers of 3% volume fraction (4.5% weight fraction) in an extruder and the tensile specimen is injection-molded. The layer-removal process, in which removing successive thin uniform layers of the material from the surface of the specimen by a milling machine, is employed and the resulting curvature is acquired by means of an image processing. The isotropic elastic analysis proposed by Treuting and Read which assumes a constant Yaung’s modulus in the thickness direction is one of the most frequently used methods to determine residual stresses. However, injection molded short fiber composites experience complex fiber orientation during molding and variation of Yaung’s modulus distribution occurs in the specimen. In this study, variation of Yaung’s modulus with respect to the thickness direction is considered for calculation of the residual stresses as proposed by White and the result is compared with that by assuming constant modulus. Residual stress distribution obtained from this study shows a typical stress profile of injection-molded products as reported in many literatures. Young’s modulus distribution is predicted by using numerical methods instead of experimental results. For the numerical analysis of injection molding process, a hybrid FEM/FDM method is used in order to predict velocity, temperature field, fiber orientation, and resulting mechanical properties of the specimen at the end of molding.

• The Pure and Applied Mathematics
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• v.21 no.1
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• pp.1-10
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• 2014

In this paper, we study the curvature of locally symmetric or semi-symmetric half lightlike submanifolds M of an indefinite Kenmotsu manifold $\bar{M}$, whose structure vector field is tangent to M. After that, we study the existence of the totally geodesic screen distribution of half lightlike submanifolds of indefinite Kenmotsu manifolds with parallel co-screen distribution subject to the conditions: (1) M is locally symmetric, or (2) the lightlike transversal connection is flat.

• Honam Mathematical Journal
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• v.29 no.1
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• pp.75-81
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• 2007

The Fisher information matrix plays a significant role in statistical inference in connection with estimation and properties of variance of estimators. In this paper, the parameter space of the normal distribution using its Fisher's matrix is defined. The Riemannian curvature and J-divergence to parameter space are calculated.

• Honam Mathematical Journal
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• v.28 no.3
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• pp.433-438
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• 2006

The Fisher information matrix plays a significant role in statistical inference in connection with estimation and properties of variance of estimators. In this paper, the parameter space of the t-distribution using its Fisher's matrix is defined. The Riemannian and scalar curvatures to parameter space are calculated.

• Honam Mathematical Journal
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• v.30 no.3
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• pp.487-504
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• 2008

In this paper we study the geometry of codimension 2 screen conformal Einstein half lightiike submanifolds M of a semi-Riemannian manifold $(\={M}(c),\={g})$ of constant curvature c, with a Killing co-screen distribution on $\={M}$. The main result is a classification theorem for screen homothetic Einstein half lightlike submanifold of Lorentzian space forms.

• Communications of the Korean Mathematical Society
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• v.22 no.3
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• pp.411-417
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• 2007

N(k)-quasi Einstein manifolds are introduced and studied.

• Journal of applied mathematics & informatics
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• v.6 no.3
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• pp.921-928
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• 1999

K. Kenmotsu introduced and studied the so-called Kenmotsu manifold related to the warped product space. In this paper we charac-terize a Kenmotsu Manifold using the fibred Riemannian space.

• Journal of the Korean Statistical Society
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• v.24 no.2
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• pp.419-437
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• 1995

Given the specific mean shift outlier model, several standard approaches to obtaining test statistic for outliers are discussed. Each of these is developed in detail for the nonlinear regression model, and each leads to an equivalent distribution. The geometric interpretations of the statistics and accuracy of linear approximation are also presented.