• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.542-545
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• 1990

Texture provides an important source of information about the local orientation of visible surfaces. In this study the 3D shape of a textured surface is recovered from its perspective projection image on the assumption that the texture is homogeneously distributed. To recover 3D structure, the distorting effects of the perspective projection must be distinguished from properties of the texture. In this study, paraperspective projection, approximation of perspective projection, has employed.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2006.04a
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• pp.369-373
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• 2006

A 3D modeling of urban area can be composed the terrain modeling that can express specific and shape of the terrain and the object modeling such as buildings, trees and facilities which are found in urban areas. Especially in a 3D modeling of building, it is very important to make a unit model by simplifying 3D structure and to take a texture mapping, which can help visualize surface information. In this study, the texture mapping technique, based on library for 3D urban modeling, was used for building modeling. This technique applies the texture map in the form of library which is constructed as building types, and then take mapping to the 3D building frame. For effectively apply, this technique, we classified buildings automatically using LiDAR data and made 3D frame using LiDAR and digital map. To express the realistic building texture, we made the texture library using real building photograph.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.10
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• pp.603-609
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• 2004

Procedural texture has many advantages that its representation is extremely compact and unfixed in resolution. However, it can be difficult for an end-user having no programming skill to build and debug. This paper presents a new interactive design system for procedural texture generation. The user's interactive design process based on multi-layer operations is represented with a graph structure, which consists of the data node, the operation and the output. Since our system generates automatically a shading language, a user who is not acquainted with implicit concepts can make procedural texturing by using an intuitive and flexible interface. Simulation results showed that the proposed method can make a variety of texture patterns efficiently.

• Journal of Powder Materials
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• v.10 no.2
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• pp.103-107
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• 2003

Aluminum-based $Al/Al_2O_3$ composites were fabricated by a powder-in sheath rolling method. A stainless steel tube with outer diameter of 12 mm and wall thickness of 1 mm was used as a sheath. A mixture of aluminum powder and $Al_2O_3$ particles of which volume content was varied from 5 to 20%, was filled in the tube by tap filling and then rolled by 75% reduction in thickness at ambient temperature. The rolled specimen was then sintered at 56$0^{\circ}C$ for 0.5 h. The mixture of Al powders and $Al_2O_3$ particles was successfully consolidated by the sheath rolling. The $Al/Al_2O_3$ composite fabricated by the sheath rolling showed a recrystallized structure, while unreinforced Al powder compact fabricated by the same procedure showed a deformed structure. The unreinforced Al powder compact was characterized by a deformation (rolling) texture of which main component is {112}<111>, while the $Al/Al_2O_3$ composite showed a mixed texture oi deformation and recrystallization. The sintering resulted in recrystallization in Al powder compact and grain growth in the composite.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.08a
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• pp.11-18
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• 2004

Asymmetric rolling, in which the circumferential velocities of the upper and lower rolls are different, can give rise to intense plastic shear strains and in turn shear deformation textures through the sheet thickness. The ideal shear deformation texture of fcc metals can be approximated by the <111> // ND and $\{001\}<110>$ orientations, among which the former improves the deep drawability. The ideal shear deformation texture for bcc metals can be approximated by the Goss $\{110\}<001>\;and\;\{112\}<111>$ orientations, among which the former improves the magnetic permeability along the <100> directions and is the prime orientation in grain oriented silicon steels. The intense shear strains can result in the grain refinement and hence improve mechanical properties. Steel sheets, especially ferritic stainless steel sheets, and aluminum alloy sheets may exhibit an undesirable surface roughening known as ridging or roping, when elongated along RD and TD, respectively. The ridging or roping is caused by differently oriented colonies, which are resulted from the <100> oriented columnar structure in ingots or billets, especially for ferritic stainless steels, that is not easily destroyed by the conventional rolling. The breakdown of columnar structure and the grain refinement can be achieved by asymmetric rolling, resulting in a decrease in the ridging problem.

• Korean Journal of Food Science and Technology
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• v.27 no.1
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• pp.105-111
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• 1995

The relationship betwwen the molecular structure of amylopectin and the texture of cooked rice was investigated using Korean rice [3 varieties of Japonica type and 3 varieties of Tongil type(Japonica-Indica breeding type)]. The molecular structure of rice amylopectin was polymodal and distributed A chain of $\overline{DP}$ 12.4, short B chain of $\overline{DP}$ 20.6, B chain of $\overline{DP}$ 26.3, long B chain of $\overline{DP}$ 45 and super long chain of above $\overline{DP}$ 55. The super long chain of amylopectin was composed of long linear chain with poorly branched chain. Also, the super long chain of amylopectin showed positive correlated with average chain length, inherent viscosity and ${\beta}-amyloysis$ limit$({\%})$, but negative correlated with ${\lambda}max$ of iodine reaction of amylopectin. The structural properties of amylopectin in Japonica type were different from those of amylopectin in Tongil type. In relationship between molecular structure of amylopectin and texture of cooked rice, the average chain length, inherent viscosity, ${\beta}-amyloysis$ limit and super long chain of amylopectin was showed a positive correlation with hardness, but a negative correlation with adhesiveness of cooked rice. The long chain of rice amylopectin is the less, the eating quality of cooled rice was the better. These results suggest that the molecular structure of rice amylopectin could be responsible for the texture of cooked rice.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.744-746
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• 2003

A 3D modeling of urban area can be composed the terrain modeling that can express specific and shape of the terrain and the object modeling such as buildings, trees and facilities which are found in urban areas. Especially in a 3D modeling of building, it is very important to make a unit model by simplifying 3D structure and to take a texture mapping, which can help visualize surface information. In this study, the texture mapping technique, based on library for 3D urban modeling, was used for building modeling. This technique applies the texture map in the form of library which is constructed as building types, and then take mapping to the 3D building frame. For effectively apply, this technique, we classified buildings automatically using LiDAR data and made 3D frame using LiDAR and digital map. To express the realistic building texture, we made the texture library using real building photograph.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.323-323
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• 2010

Saw damage of crystalline silicon wafer is unavoidable factor. Usually, alkali treatment for removing the damage has been carried out as the saw damage removal (SDR) process for priming the alkali texture. It usually takes lots of time and energy to remove the sawed damages for solar grade crystalline silicon wafers We implemented two different mixed acidic solution treatments to obtain the improved surface structure of silicon wafer without much sacrifice of the silicon wafer thickness. At the first step, the silicon wafer was dipped into the mixed acidic solution of $HF:HNO_3$=1:2 ration for polished surface and at the second step, it was dipped into the diluted mixed acidic solution of $HF:HNO_3:H_2O$=7:3:10 ratio for porous structure. This double treatment to the silicon wafer brought lower reflectance (25% to 6%) and longer carrier lifetime ($0.15\;{\mu}s$ to $0.39\;{\mu}s$) comparing to the bare poly-crystalline silicon wafer. With optimizing the concentration ratio and the dilution ratio, we can not only effectively substitute the time consuming process of SDR to some extent but also skip plasma enhanced chemical vapor deposition (PECVD) process. Moreover, to conduct alkali texture for pyramidal structure on silicon wafer surface, we can use only nitric acid rich solution of the mixed acidic solution treatment instead of implementing SDR.

• Journal of the Korean Society for Heat Treatment
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• v.34 no.3
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• pp.122-129
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• 2021

This study focuses on the microstructural development of 99% magnesium alloy sheet manufactured using twin roll casting (TRC) process. Herein, a plate with a thickness of 5 mm was manufactured using the TRC process, homogenization heat treatment was performed at 400℃ for 2-32 h, and finally, the change in microstructure was evaluated via optical microscopy and textural analysis. The results suggest that the plate manufactured using the TRC process was not destroyed and was successfully rolled into a plate. Microscopic observation suggested that the dendritic cast structure was arranged along the rolling direction. And the central layer of the rolled plate, where was present in a liquid state at the beginning of rolling, solidified later during the TRC process to form central segregation. The initial cast structure and inhomogeneous structure of the plate were recrystallized by homogenization heat treatment for only 2 h, and it was confirmed that the segregated part of the central layer became homogeneous and recrystallization occurred. Grain growth occurred as the heat treatment time increased, and secondary recrystallization occurred, wherein only some grains were grown. The textural analysis, which was conducted via X-ray diffraction, confirmed that the relatively weak basal plane texture developed using the TRC process was formed into a random texture after heat treatment.

• Korean Journal of Computational Design and Engineering
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• v.4 no.1
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• pp.1-11
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• 1999

surface texture denotes set of tiny repetitive geometric features on an object surface. 3D Printing can readily create a surface of controlled macro-textures of high geometric complexity. Designing surface textures for 3D Printing, however, is difficult due to complex macro-structure of the tiny texture geometry since it needs to be compatible with the non-traditioal manufacturing method. In this paper we propose a visual simulation technique involving development of a virtual model-an intermediate geometric model-of the surface texture design prior to fabricating the physical model. Careful examination of the virtual model before the actual fabrication can help minimize unwanted design iterations. The proposed technique demonstrated visualization capability by comparing the virtual model with the physical model for several test cases.