• The Journal of the Acoustical Society of Korea
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• v.19 no.3
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• pp.20-25
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• 2000

This paper proposes the method of surface classification and threshold value selection for surface classification of the three-dimensional object recognition. The processings of three-dimensional image processing system consist of three steps, i.e, acquisition of range data, feature extraction and matching process. This paper proposes the method of shape feature extraction from the acquired rage data in the entire three-dimensional image processing system. In order to achieve these goals, firstly, this article proposes the surface classification method by using the distribution characteristics of sign value from range values. Also pre-existing method which uses the K-curvature and K-curvature has limitation in the practical threshold value selection. To overcome this, this article proposes the selection of threshold value for surface classification. Finally, the effectiveness of this article is demonstrated by the several experiments.

• Journal of Periodontal and Implant Science
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• v.24 no.1
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• pp.1-14
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• 1994

Dental calculus which is calcifing and/or calcified dental plaque is divided into supragingival calculus and subgingival calculus according to the position of deposit to gingival margin. Subgingival calculus has more important clinical significance in diagnosis and treatment of periodontal disease than supragingival calculus. In order to investigate the deposition pattern of subgingival calculus on each root surface of different tooth type, extracted 192 teeth due to excessive destruction of periodontal tissue were divided according to tooth type and the deposition pattern of subgingival calculus was classified into linear type, veneer type, scattered type, and aggregated type according to the configuration and the extent of deposit. The difference of percentage between each deposition pattern was statistically analyzed by Chi-Square test. Following results were obtained : l. In maxillary incisors, linear type and aggregated type were predominant deposition pattern of subgingival calculus on labial(45.5%, 36.4%) and palatal(36.4%, 36.4%) root surface, aggreated type(72.7%) was on mesial surface, and aggregated type(54.5%) and scattered type(36.4%) was on distal suface. 2. In mandibular incisors, scattered type, linear type and aggregated type were predominant deposition pattern of subgingival calculus on labial(33.3%, 30.6%, 27.8%) and lingual(36.1%, 30.6%, 25.0%) root surface, aggregated type(33.3%), scattered type(27.8% ), and veneer type(27.8%) were on mesial surface, and aggregated type(38.9%) and scattered type(33.3%) on distal surface. 3. In maxillary peremolars, the predominant deposition patterns of subgingival calculus were linear type(28.6%) on buccal root suface, scattered type(35.7%) and linear type(28.6%) on palatal surface, scattered type(39.3%) on mesial surface, aggregated type(46.4%) on distal surface, and aggregated type(53.6%) on furcation area. 4. In mandibular premolars, scattered type was predominant deposition pattern of subgingival calculus on buccal(39.3%) and lingual(50.0%) root surface, scattered type(32.1%) and aggregated type(32.1% ) were on mesial surface, and aggregated type(42.9%) was on distal surface. 5. In maxillary molars, aggregated type(40.0%) and scattered type(32.5%) were predominat deposition pattern of subgingival calculus on buccal root surface, aggregated type was on distal(40.0%) and furcation area(50.0%), but there was no predominat pattern on palatal and mesial root surfaces. 6. In mandibular molars, aggregated type(39.5%) and scattered type(28.9%) were predominant deposition patterns of subgingival calculus on buccal root surface, aggregated type(36.8%) was on lingual surface, linear type(39.5%) and aggregated type(34.2%) were on furcation area, but there was no predominant pattern on mesial and distal root surfaces.

• Biomolecules & Therapeutics
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• v.24 no.5
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• pp.475-481
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• 2016

PICK1, a PDZ domain-containing protein, is known to increase the reuptake activities of dopamine transporters by increasing their expressions on the cell surface. Here, we report a direct and functional interaction between PICK1 and dopamine $D_3$ receptors ($D_3R$), which act as autoreceptors to negatively regulate dopaminergic neurons. PICK1 colocalized with both dopamine $D_2$ receptor ($D_2R$) and $D_3R$ in clusters but exerted different functional influences on them. The cell surface expression, agonist affinity, endocytosis, and signaling of $D_2R$ were unaffected by the coexpression of PICK1. On the other hand, the surface expression and tolerance of $D_3R$ were inhibited by the coexpression of PICK1. These findings show that PICK1 exerts multiple effects on $D_3R$ functions.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.1 s.173
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• pp.144-155
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• 2000

초록 The validity, of a single parameter such as stress intensity, factor K or J-integral in traditional fracture mechanics depends strongly on the geometry, and loading condition. Therefore the second parameter like T-stress measuring the stress constraint is additionally needed to characterize the general crack-tip fields. While many, research works have been done to verify, the J-T description of elastic-plastic crack-tip stress fields in plane strain specimens, limited works (especially. for bimaterials) have been performed to describe the structural surface crack-front stress fields with the two parameters. On this background, via detailed three dimensional finite element analyses for surface-cracked plates and straight pipes of homogeneous materials and bimaterials under various loadings, we investigate the extended validity or limitation of the two parameter approach. We here first develop a full 3D mesh generating program for semi-elliptical surface cracks, and calculate elastic T-stress from the obtained finite element stress field. Comparing the J-T predictions to the elastic-plastic stresses from 3D finite element analyses. we then confirm the extended validity of fracture mechanics methodology based on the J-T two parameters in characterizing the surface crack-front fields of welded plates and pipes under various loadings.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.3 s.174
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• pp.550-559
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• 2000

One of the most important factor to be considered for the analysis of sheet metal forming processes is the tool surface description for arbitrarily- shaped sheet metal parts. In the present study , finite element approach is used to describe the arbitrarily shaped tool surface. In finite element mesh approach, tool surfaces ar, described by finite elements. The finite elements mesh description of the tool surface, which is originally described by CAD data, needs much time and time-consuming graphic operation. The method, however, has been widely used to describe a complex tool surface. In the present study, the contact searching algorithm for the finite element mesh approach is developed based on cell strategy method and sheet surface normal scheme. For the verification purpose, a clover cup drawing, Baden-Baden oilpan problem and a trunk floor drawing were investigated. The computational results based on the finite element approach were compared with the results of available parametric patch approach and experiments.

• East Asian mathematical journal
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• v.35 no.5
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• pp.589-595
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• 2019

In this paper, we prove that a special supersingular K3 surface of Artin invariant ${\sigma}$ over a field of odd characteristic p has a model over a finite field of $p^{2{\sigma}}$ elements.

• Bulletin of the Korean Mathematical Society
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• v.60 no.6
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• pp.1427-1437
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• 2023

It is known that the automorphism group of a K3 surface with Picard number two is either an infinite cyclic group or an infinite dihedral group when it is infinite. In this paper, we study the generators of such automorphism groups. We use the eigenvector corresponding to the spectral radius of an automorphism of infinite order to determine the generators.

• Journal of Magnetics
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• v.13 no.4
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• pp.144-148
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• 2008

The size and surface effects on the magnetism of a fcc Fe (001) surface was investigated by performing firstprinciples calculations on 3, 5, 7, and 9 monolayers fcc Fe (001) single slabs with two different two-dimensional lattice constants, ${\alpha}=3.44{\AA}$ (System I) and 3.65 ${\AA}$ (System II), using the all-electron full-potential linearized augmented plane wave method within a generalized gradient approximation. The surface layers were coupled ferromagnetically to the subsurface layer in both systems. However, the magnetism of the inner layers was quite different from each other. While all the inner layers of System II were ferromagnetically coupled in the same way as the surface layer, the inner layers of System I showed a peculiar magnetism, bilayer antiferromagnetism. The calculated spin magnetic moments per Fe atom were approximately 2.7 and 2.9 ${\mu}_B$ at the surface for Systems I and II, respectively, due to the almost occupied Fe d-state being in the majority spin state and band narrowing. The spin orientations of System I were out-of-plane regardless of its thickness, whereas the orientation of System II changed from out-of-plane to in-plane with increasing thickness.

• Macromolecular Research
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• v.17 no.6
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• pp.388-396
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• 2009

The surface properties (water sorption and repellency, adhesion) are closely related to the surface tension of polymer solids. The critical surface tension (${\gamma}_c$) and surface tension (${\gamma}_s$) of a polymer solid were estimated by the contact angle method by our quantitative imaging system. BPDA (3,3',4,4'-biphenyl tetracarboxylic dianhydride)-BAPP (1,3-Bis(4-aminophenoxy) propane) polyimide was successfully synthesized. The ${\gamma}_c$ values were analyzed by a Zisman plot, a Young-$Dupr\acute{e}$-Good-Girifalco plot, and a log ($1+cos{\theta}$) vs log ${\gamma}_L$ plot. The ${\gamma}_s$ value of BPDA-BAPE polyimide was evaluated using the geometric mean equation and our multiple regression analysis. The calculated values of ${{\gamma}_s^d$ (a dispersion component), ${{\gamma}_s^p$ (a polar component), ${{\gamma}_s^h$ (a hydrogen bonding component), and ${\gamma}_s$ were 30.79, 9.32, 0.20, and 40.31 $mN{\cdot}m^{-1}$, respectively. The ${\gamma}_s$ of BPDA-BAPP polyimide containing both a methylene group and an ether group was larger than that of the polyimide containing only a methylene group.

• Proceedings of the KIEE Conference
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• 1991.11a
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• pp.67-70
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• 1991

When analyzing field or optimizing the shape of electrode in three dimensional space by using the surface charge method, we need to divide finely the surface of electrode into surface element like triangle or rectangle. In this case, there exist any variables in field analysis or field optimization. In particular, smoothness on the surface of optimized shape is not good. Recently, A paper is published where introducing NURB curve to field analysis and field optimization about two dimensional space model and axial symmetric three dimensional space model results in reduced variables, enhenced accuracy and improved smoothness. NURB curve has some useful properties like continuity, controllability and locality. Therefore in this paper, in order to improve the demerits of the established optimization method for three dimensional space models, the NURB surface that has same properties in common with NURB curve is used to analyze and optimize simple model.