• Title/Summary/Keyword: Texture properties

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Asymmetric Rolling as Means of Texture and Ridging Control and Grain Refinement (집합조직과 이랑형표면결함의 제어 및 결정립 미세화 수단으로서의 비대칭압연)

  • Lee D.N.
    • 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.

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Pastic Strain Ratio and Texture Evolution of Aluminum/Polypropylene/Aluminum Sandwich Sheets (알루미늄 5182-폴리프로필렌 샌드위치 판재의 소성변형비 및 집합조직의 발달)

  • Kim, Kee-Joo;Jeong, Hyo-Tae
    • Transactions of the Korean Society of Automotive Engineers
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    • v.14 no.2
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    • pp.57-66
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    • 2006
  • AA5182-polypropylene sandwich sheet was manufactured, and the mechanical properties evaluation was executed in order to identify $L{\ddot{u}}ders$ band that causes fabrication process problem and especially surface roughness. To identify formability, deformation behavior, plastic strain ratio (R-value) and pole figure were measured, and texture analysis was performed. In the case of sandwich sheet, the unstable deformation behavior has decreased. As well, for sandwich sheet, A1 skin could manage the most of load, and the elongation has improved about 45% more than that of A1 skin. The plastic strain ratio of A1 skin and sandwich panel, which indicates serration behavior, was obtained from instantaneous plastic strain ratio evaluation. Also, the planar anisotropy of sandwich sheet has decreased more than that of A1 skin. According to these results, the sandwich sheet produced lightening effect and could control unstable deformation characteristic, that is, surface roughness caused by $L{\ddot{u}}ders$ band. Furthermore, it was proved that the texture control of the rolling attachment of A1 skin is necessary to improve the formability of the sandwich panel.

Plastic Strain Ratio and Texture of the ECAPed and Heat-treated Aluminum AA 1050 Sheet (ECAP 한 후 열처리한 알루미늄 AA 1050 합금 판재의 집합조직과 소성변형비 변화)

  • Akramov Saidmurod;Lee M. K.;Park B. H.;Kim I.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2005.10a
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    • pp.369-372
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    • 2005
  • A study on the microstructure, the texture and the formability of the samples after ECAPed and subsequent heat-treated AA 1050 aluminum alloy sheet have been carried out. The specimens after the ECAP showed a very fine grain size, a decrease of <100> // ND. The <110>// ND textures appears in the specimens after the ECAP and subsequent heat-treatment at $400^{\circ}C$ for 1 hour. One of the most important properties in sheet metals is formability. The r-value or plastic strain ratio has was as a parameter that expressed the formability of sheet metals. The change of the plastic Strain ratios after the ECAP and subsequent heat-treatment conditions were investigated and it was found that they were two times higher than those of the initial Al sheets. This could be attributed to the formation above texture components through the ECAP and subsequent heat-treatment of AA 1050 Aluminum alloy sheet.

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Determination of the Proper Block Size for Estimating the Fractal Dimension (프락탈 디멘션을 근사하기 위한 적당한 브록 크기 결정에 관한 연구)

  • Jang, Jong-Hwan
    • The Journal of Natural Sciences
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    • v.7
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    • pp.67-73
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    • 1995
  • In this paper, a new texture segmentation-based image coding technique which performs segmentation based on properties of the human visual system (HVS) is presented. This method solves the problems of a segmentation-based image coding technique with constant segments by proposing a methodology for segmenting an image into texturally homogeneous regions with respect to the degree of roughness as perceived by the HVS. The segmentation is accomplished by thresholding the fractal dimension so that textural regions are classified into three texture classes; perceived constant intensity, smooth texture, and rough texture. It is very important to determine the proper block size for estimating the fractal dimension. Good quality reconstructed images are obtained with about 0.1 to 0.25 bit per pixel (bpp) for many different types of imagery.

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Fabrication of Biaxially Textured Ni Tapes from Ni Powder Compact Rods (분말 성형체로부터 양축정렬 집합조직을 갖는 니켈 테이프의 제조)

  • 이동욱;지봉기;주진호;김찬중
    • Journal of Powder Materials
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    • v.10 no.4
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    • pp.241-248
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    • 2003
  • Biaxially textured Ni tapes were fabricated by a cold working and recrystallization heat treatment processes from powder compact rods. The processing parameters associated with the cube texture formation in Ni tapes were systematically investigated by using X-ray diffraction and pole-figure analysis. The Ni powder used in this study was 5 $\mu$m in size and 99.99% in purity. To find the optimum sintering temperature, tensile tests were performed for Ni rods sintered at various temperatures. The Ni rods sintered at 100$0^{\circ}C$ showed poor elongation and low fracture strength, while the Wi rods sintered above 100$0^{\circ}C$ revealed good mechanical properties. The higher elongation and fracture strength of the Ni rods sintered at higher temperatures than 100$0^{\circ}C$ are attributed to the full densification of the sintered rods. The sintered Ni rods were cold-rolled with 5% reduction to the final thickness of 100 $\mu$m and then annealed for development of rube texture in rolled Ni tapes. The annealed Ni tapes depicted strong cube texture with FWHM(full-width at half-maximum) of in-plane and out-of-plane in the range of 8$^{\circ}$ to 10$^{\circ}$. The NiO deposited on the Ni tapes by MOCVD process showed good epitaxy with FWHM=10$^{\circ}$, which indicates that the Ni tapes can be used as a substrate for YBCO coated conductors.

Construction of Abalone Sensory Texture Evaluation System Based on BP Neural Network

  • Li, Xiaochen;Zhao, Yuyang;Li, Renjie;Zhang, Ning;Tao, Xueheng;Lee, Eung-Joo
    • Journal of Korea Multimedia Society
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    • v.22 no.7
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    • pp.790-803
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    • 2019
  • The effects of different heat treatments on the sensory characteristics of abalones are studied in this study. In this paper, the sensory evaluation of abalone samples under different heat treatment conditions is carried out, and the evaluation results are analyzed. The three-dimensional (3D) scanning and reverse engineering are used in tooth modeling of the sensory evaluation of abalone samples under different heat treatment conditions. Besides, the chewing movement models are simplified into three modes, including the cutting mode, compressing mode and grinding mode, which are simulated using finite element simulation. The elastic modulus of the abalone samples is obtained through the compression testing using a texture analyzer to distinguish their material properties under different heat treatments and to obtain simulated mechanical parameters. Finally, taking the mechanical parameters of the finite element simulation of abalone chewing as input and sensory evaluation parameters as the output, BP neural network is established in which the sensory texture evaluation model of abalone samples is obtained. Through verification, the neural network prediction model can meet the requirements of food texture evaluation, with an average error of 9.12%.

Estimating Surface Orientation Using Statistical Model From Texture Gradient in Monocular Vision (단안의 무늬 그래디언트로 부터 통계학적 모델을 이용한 면 방향 추정)

  • Chung, Sung-Chil;Choi, Yeon-Sung;Choi, Jong-Soo
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.26 no.7
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    • pp.157-165
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    • 1989
  • To recover three dimensional information in Shape from Texture, the distorting effects of projection must be distinguished from properties of the texture on which the distortion acts. In this paper, we show an approximated maximum likelihood estimation method in which we find surface orientation of the visible surface (hemisphere) in gaussian sphere using local analysis of the texture. In addition, assuming that an orthogonal projection and a circle is an image formation system and a texel (texture element) respectively, we drive the surface orientation from the distribution of variation by means of orthogonal projection of a tangent direction which exists regularly in the arc length of a circle. We present the orientation parameters of textured surface with slant and tilt in gradient space, and also the surface normal of the resulted surface orientationas as needle map. This algorithm is applied to geographic contour (artificially generated chejudo) and synthetic texture.

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Texture Image and Preference of Men's Wool/Wool blend Suit Fabrics (남성 정장용 양모 직무의 질감 이미지와 선호도 분석)

  • 배현주;김은애
    • Journal of the Korean Society of Clothing and Textiles
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    • v.27 no.11
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    • pp.1318-1329
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    • 2003
  • The purpose of this study was to examine the effects of the structural characteristics of men's suit fabrics on the texture image and the preference, and to analyze the relationship between the preference and the practical sales ratio. In addition, the texture images and the preference of fabric and jackets made of the same fabrics were compared. As specimen, jackets for men's suit of 2002' S/S and their fabrics were collected. Questionnaires composed of 22 sensibility related and 21 fabric image related adjectives were developed. For the subjective evaluation of the texture image, both jackets and fabric samples were tested. Tests were performed with 100 female subjects in clothing department and apparel industry. For the objective evaluation, structural characteristics such as fiber contents, yarn twist, fabric count, thickness and weight were analyzed. Total Hand Value were calculated from mechanical properties determined by the KES-FB system. Factor analysis showed sensibilities were classified into 6 categories; "surface roughness", "weight", "density", "stiffness", "elasticity" and "wetness". Fabric images were classified into 4 categories; "classic", "original", "practical", and "stuffy". Depending on the method to show the specimen to the subjects, whether it is suit or fabric, statistically significant differences were observed with a number of adjectives for sensibilities and fabric images. The results of THV of KES did not agree with the preference of subjects, which suggests that we should be careful when using the KES system, which was developed for Japanese people. Price was considered to be another factor besides the texture image that influenced on purchase.

Effect of Addition of Enzyme-Resistent Starch on Texture Characterstics of Corn Bread (효소 저항성 전분의 첨가가 옥수수빵의 텍스쳐 특성에 미치는 영향)

  • 조아라;안승요
    • Korean journal of food and cookery science
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    • v.12 no.2
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    • pp.207-213
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    • 1996
  • Effects of replacement of corn starch with Amylomaize Vll starch and addition of enzyme-resistant starch on texture characteristics of com bread (CON) were investigated. Amylomaize-substituted corn bread (AMZ) was made by replacing corn starch with Amylomaize Vll starch. 15% (RSl5) and 30% (RS30) of butter, was replaced with enzyme-resistant starch (RS) from Amylomaife Vll starch, respectively. Textu,e describing terms were classified according to their physical properties. Result of sensory evaluation characteristics showed that the size of air cells increased as butter replacement level decreased and that hardness increased but springiness decreased as com starch was replaced with Amylomaize Vll starch. The results of Texture Profile Analysis with deformation of 30% and 50% showed that hardness inclosed but cohesiveness decreased as cooling time increased.

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Magnetic resonance imaging texture analysis for the evaluation of viable ovarian tissue in patients with ovarian endometriosis: a retrospective case-control study

  • Lee, Dayong;Lee, Hyun Jung
    • Journal of Yeungnam Medical Science
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    • v.39 no.1
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    • pp.24-30
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    • 2022
  • Background: Texture analysis has been used as a method for quantifying image properties based on textural features. The aim of the present study was to evaluate the usefulness of magnetic resonance imaging (MRI) texture analysis for the evaluation of viable ovarian tissue on the perfusion map of ovarian endometriosis. Methods: To generate a normalized perfusion map, subtracted T1-weighted imaging (T1WI), T1WI and contrast-enhanced T1W1 with sequences were performed using the same parameters in 25 patients with surgically confirmed ovarian endometriosis. Integrated density is defined as the sum of the values of the pixels in the image or selection. We investigated the parameters for texture analysis in ovarian endometriosis, including angular second moment (ASM), contrast, correlation, inverse difference moment (IDM), and entropy, which is equivalent to the product of area and mean gray value. Results: The perfusion ratio and integrated density of normal ovary were 0.52±0.05 and 238.72±136.21, respectively. Compared with the normal ovary, the affected ovary showed significant differences in total size (p<0.001), fractional area ratio (p<0.001), and perfusion ratio (p=0.010) but no significant differences in perfused tissue area (p=0.158) and integrated density (p=0.112). In comparison of parameters for texture analysis between the ovary with endometriosis and the contralateral normal ovary, ASM (p=0.004), contrast (p=0.002), IDM (p<0.001), and entropy (p=0.028) showed significant differences. A linear regression analysis revealed that fractional area had significant correlations with ASM (r2=0.211), IDM (r2=0.332), and entropy (r2=0.289). Conclusion: MRI texture analysis could be useful for the evaluation of viable ovarian tissues in patients with ovarian endometriosis.