• Nuclear Engineering and Technology
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• v.56 no.4
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• pp.1538-1543
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• 2024

The importance of determining the radon exhalation rate from water surface is emphasized by the increased use of radon and its daughter products as tracers in large-scale circulation studies of the atmosphere. There were many methods to measure radon exhalation from water surface. With the development of radon exhalation rate measurement methods and instruments on the surface of the soil, the rock and building materials, so the radon exhalation rate from water surface can be more accurately measured by applying these improved methods and instruments. In this paper, a cuboid accumulation chamber surrounded by foam boards and a RAD7 were used to measure the radon exhalation rate on the water surface at three different positions by Yixin lake. Each measurement was performed 2 h. The radon exhalation rate from the water surface was about 6 × 10^-3 Bq m^-2s^-1. The thoron exhalation rate from the water surface also can be estimated, it is about 0.16 Bq m^-2s^-1. These results hint that the radon transmission from the lake bottom soil to water and then into the atmosphere.

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.232.1-232.1
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• 2008

• Journal of Computational Design and Engineering
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• v.2 no.2
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• pp.79-87
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• 2015

Surface segmentation and edge feature lines extraction from fractured fragments of relics are essential steps for computer assisted restoration of fragmented relics. As these fragments were heavily eroded, it is a challenging work to segment surface and extract edge feature lines. This paper presents a novel method to segment surface and extract edge feature lines from triangular meshes of irregular fractured fragments. Firstly, a rough surface segmentation is accomplished by using a clustering algorithm based on the vertex normal vector. Secondly, in order to differentiate between original and fracture faces, a novel integral invariant is introduced to compute the surface roughness. Thirdly, an accurate surface segmentation is implemented by merging faces based on face normal vector and roughness. Finally, edge feature lines are extracted based on the surface segmentation. Some experiments are made and analyzed, and the results show that our method can achieve surface segmentation and edge extraction effectively.

• BMB Reports
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• v.50 no.6
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• pp.285-298
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• 2017

The cancer stem cell (CSC) hypothesis has captured the attention of many scientists. It is believed that elimination of CSCs could possibly eradicate the whole cancer. CSC surface markers provide molecular targeted therapies for various cancers, using therapeutic antibodies specific for the CSC surface markers. Various CSC surface markers have been identified and published. Interestingly, most of the markers used to identify CSCs are derived from surface markers present on human embryonic stem cells (hESCs) or adult stem cells. In this review, we classify the currently known 40 CSC surface markers into 3 different categories, in terms of their expression in hESCs, adult stem cells, and normal tissue cells. Approximately 73% of current CSC surface markers appear to be present on embryonic or adult stem cells, and they are rarely expressed on normal tissue cells. The remaining CSC surface markers are considerably expressed even in normal tissue cells, and some of them have been extensively validated as CSC surface markers by various research groups. We discuss the significance of the categorized CSC surface markers, and provide insight into why surface markers on hESCs are an attractive source to find novel surface markers on CSCs.

• Journal of Computational Design and Engineering
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• v.2 no.3
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• pp.129-136
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• 2015

This paper proposes a novel method for shape design of a Bezier surface with given boundary curves. The surface is defined as the minimizer of an extended membrane functional or an extended thin plate functional under the guidance of a specified normal field together with an initial prescribed surface. For given boundary curves and the guiding normal field, the free coefficients of a Bezier surface are obtained by solving a linear system. Unlike previous PDE based surface modeling techniques which construct surfaces just from boundaries, our proposed method can be used to generate smooth and fair surfaces that even follow a specified normal field. Several interesting examples are given to demonstrate the applications of the proposed method in geometric modeling.

• East Asian mathematical journal
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• v.40 no.1
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• pp.75-83
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• 2024

For a reduced, irreducible and nondegenerate curve C ⊂ ℙ^r of degree d, it was shown that the arithmetic genus g of C has an upper bound π₀(d, r) by G. Castelnuovo. And he also classified the curves that attain the extremal value. These curves are arithmetically Cohen-Macaulay and contained in a surface of minimal degree. In this paper, we investigate the arithmetic genus of curves lie on a surface of minimal degree - the Veronese surface, smooth rational normal surface scrolls and singular rational normal surface scrolls. We also provide a construction of curves on singular rational normal surface scroll S(0, 2) ⊂ ℙ³ which attain the maximal arithmetic genus.

• Journal of Korea Game Society
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• v.10 no.6
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• pp.169-178
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• 2010

An effective method to render realistic metallic surface in realtime application is proposed. The proposed method perturbs the normal vectors on the metallic surface to represent small scratches. In general, bump map or normal map method is used to gnerate normal vector perturbation. However, those methods do not show plausible light scattering when applied to anisotropic reflection surface. In order to express metallic surface reflectance, MDF-based BRDF is generally employed. Therefore, the simple normal perturbation does not produce satisfactory metal rendering results. The proposed method employs not only normal perturbation but also deformation of the microfacet distribution function(MDF) that determines the reflectance properties on the surface. The MDF deformation increases the realism of metal rendering. The proposed method can be easily implemented with GPU programs, and works well in realtime environments.

• Tribology and Lubricants
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• v.39 no.6
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• pp.273-277
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• 2023

This paper presents a molecular dynamics simulation-based numerical investigation of the influence of surface energy on water lubrication. Models composed of a crystalline substrate, half cylindrical tip, and cluster of water molecules are prepared for a tribological-characteristic evaluation. To determine the effect of surface energy on lubrication, the surface energy between the substrate and water molecules as well as that between the tip and water molecules are controlled by changing the interatomic potential parameters. Simulations are conducted to investigate the indentation and sliding processes. Three different normal forces are applied to the system by controlling the indentation depth to examine the influence of normal force on the lubrication of the system. The simulation results reveal that the solid surface's surface energy and normal force significantly affect the behavior of the water molecules and lubrication characteristics. The lubrication characteristics of the water molecules deteriorate with the increasing magnitude of the normal force. At a low surface energy, the water molecules are readily squeezed out of the interface under a load, thus increasing the frictional force. Contrarily, a moderate surface energy prevents expulsion of the water molecules due to squeezing, resulting in a low frictional force. At a high surface energy, although squeezing of the water molecules is restricted, similar to the case of moderate surface energy, dragging occurs at the soil surface-water molecule interface, and the frictional force increases.

• The Korean Journal of Physiology
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• v.5 no.2
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• pp.63-70
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• 1971

In an attempt to understand the possible effects of temperature and X-irradiation on the activities of surfactant in rabbits, the pulmonary surfactant from the rabbit was subjected to the incubation at $37^{\circ}C$ and X-irradiation with 900r in vitro, and activities of surfactant were measured at 10, 30, 60, and 90 minutes. Tension-area diagram of the lung extract was recorded automatically by the modified Langmuir-wilhelmy balance with a synchronized recording system designed in this Department. A comparison was made with the normal and the following results were obtained. 1) The maximal surface tension, minimal surface tension, width of the tension area diagram at the surface area of 40% and stability index of the normal rabbit lung extract were $31.6{\pm}3.11\;dynes/cm,\;8.2{\pm}0.56\;dynes/cm,\;21.4{\pm}4.40\;dynes/cm\;and\;1.12{\pm}0.22$,respectively. 2) In the $37^{\circ}C$ incubation group, maximal surface tension was similar to the normal value, while minimal surface tension was significantly lower and stability infer was markedly higher than the normal. 3) In the group where X-irradiation of 900r in vitro was applied, maximal surface tension did not differ greatly with the normal or the $37^{\circ}C$ incubation group. The minimal surface tension was significantly lower than the normal but comparing with the $37^{\circ}C$ incubation group, some decrease in minimal surface tension was noted. The width of the tension·area diagram at 40% and stability index in the irradiated group were significantly higher than the normal but a tendency of increase was noted comparing with the $37^{\circ}C$ incubation group.

• Tribology and Lubricants
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• v.24 no.6
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• pp.332-337
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• 2008

This paper presents the surface defect analysis based on the experimental investigation of scribed glasses. The scribing process by a diamond wheel cutter is widely used as a reliable and inexpensive method for sizing of glass sheets. The wheel cutter generates a small median crack on the glass surface, which is then propagated through the glass thickness for complete separation. The surface contour patterns in which are formed during a scribing process are strongly related to wheel cutter parameters such as wheel tip surface finish, tip angle and wheel diameter, and cutting process parameters such as scribing pressure, speed and tooling technique. The scribed surface of a glass sheet provides normal Wallner lines, which represent regular median cracks and crack propagation in glass thickness, and abnormal surface roughness patterns. In this experimental study, normal and abnormal surface topographic patterns are classified based on the surface defect profiles of scribed glass sheets. A normal surface of a scribed glass sheet shows regular Wallner lines with deep median cracks. But some specimens of scribed glass sheets show that abnormal surface profiles of glass sheets in two pieces are represented by a chipping, irregular surface cracks in depth, edge cracks, and combined crack defects. These surface crack patterns are strongly related to easy breakage of the scribed glass imposed by external forces. Thus the scribed glass with abnormal crack patterns should be removed during a quality control process based on the surface defect classification method as demonstrated in this study.