• Journal of the Korean Magnetics Society
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• v.12 no.4
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• pp.132-136
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• 2002

Enhancement of crystallinity and exchange bias characteristics for NiFe/FeMn/NiFe trilayer with Si buffer layer fabricated by ion-beam deposition were examined. A Si buffer layer promoted (111) texture of fcc crystallities in the initial growth region of NiFe layer deposited on it. FeMn layers deposited on Si/NiFe bilayer exhibited excellent (111) crystal texture. The antiferromagnetic FeMn layer between top and bottom NiFe films with the buffer Si 50 ${\AA}$-thick induced a large exchange coupling field Hex with a different dependence. It was found that H$\sub$ex/ of the bottom and top NiFe films with Si buffer layer revealed large value of about 110 Oe and 300 Oe, respectively. In the comparison of two Ta and Si buffer layers, the NiFe/FeMn/NiFe trilayer with Si could possess larger exchange coupling field and higher crystallinity.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.4
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• pp.1904-1926
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• 2016

Iris recognition for biometric personnel identification has gained much interest owing to the increasing concern with security today. The image quality plays a major role in the performance of iris recognition systems. When capturing an iris image under uncontrolled conditions and dealing with non-cooperative people, the chance of getting non-ideal images is very high owing to poor focus, off-angle, noise, motion blur, occlusion of eyelashes and eyelids, and wearing glasses. In order to improve the accuracy of iris recognition while dealing with non-ideal iris images, we propose a novel algorithm that improves the quality of degraded iris images. First, the iris image is localized properly to obtain accurate iris boundary detection, and then the iris image is normalized to obtain a fixed size. Second, the valid region (iris region) is extracted from the segmented iris image to obtain only the iris region. Third, to get a well-distributed texture image, bilinear interpolation is used on the segmented valid iris gray image. Using contrast-limited adaptive histogram equalization (CLAHE) enhances the low contrast of the resulting interpolated image. The results of CLAHE are further improved by stretching the maximum and minimum values to 0-255 by using histogram-stretching technique. The gray texture information is extracted by 1D Gabor filters while the Hamming distance technique is chosen as a metric for recognition. The NICE-II training dataset taken from UBRIS.v2 was used for the experiment. Results of the proposed method outperformed other methods in terms of equal error rate (EER).

• Journal of Digital Contents Society
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• v.14 no.2
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• pp.275-282
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• 2013

In medical image processing field, object recognition is usually carried out by computerized processing of various input information such as brightness, shape, and pattern. If the information mentioned does not make sense, however, many limitations could occur with object recognition during computer processing. Therefore, this paper suggests effective object recognition method based on the magnetic resonance (MR) theory to resolve the basic limitations in computer processing. We propose the efficient method of robust gray-white matter segmentation by texture analysis through the Susceptibility Weighted Imaging (SWI) for contrast enhancement. As a result, an average area difference of 5.2%, which was higher than the accuracy of conventional region segmentation algorithm, was obtained.

• Journal of KIISE:Software and Applications
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• v.34 no.5
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• pp.476-486
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• 2007

This paper proposes a resolution enhancement method which can reconstruct high-resolution facial images from single-frame, low-resolution facial images. The proposed method is derived from example-based reconstruction methods and the morphable face model. In order to improve the performance of the example-based reconstruction, we propose the region-based reconstruction method which can maintain the characteristics of local facial regions. Also, in order to use the capability of the morphable face model to face resolution enhancement problems, we define the extended morphable face model in which an extended face is composed of a low-resolution face, its interpolated high-resolution face, and the high-resolution equivalent, and then an extended face is separated by an extended shape vector and an extended texture vector. The encouraging results show that the proposed methods can be used to improve the performance of face recognition systems, particularly to enhance the resolution of facial images captured from visual surveillance systems.

• The KIPS Transactions:PartB
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• v.10B no.6
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• pp.629-638
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• 2003

In this paper, we propose an improved method of watermarking to increase the invisibility of a watermark and robustness against attacks for the purpose of removing the embedded watermark. The proposed method adaptively selects DCT blocks and determines position and intensity for watermarking based on the characteristics of human visual system. The used features are texture, luminance and contrast. We show the experimental results against image processing attacks such as cropping, image enhancement, low pass filtering, and JPEG compression, and then discuss the performance of the proposed method.

• Progress in Superconductivity and Cryogenics
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• v.11 no.4
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• pp.20-24
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• 2009

YBCO coated conductors (CC) on the $CeO_2$-buffered IBAD-MgO template were fabricated by metal-organic deposition (MOD) Process with Ba-trifluoroacetate and fluorine-free Y and Cu precursor materials. The precursor solution was coated on $CeO_2$-buffered IBAD MgO templates using the multiple dip-coating method, decomposed into inorganic precursors by pyrolysis up to $400^{\circ}C$ within 3 h, and finally fired at $740{\sim}800^{\circ}C$ in a reduced oxygen atmosphere. Microstructure, texture, and superconducting properties of YBCO films were found highly sensitive to both the firing temperature and time. The high critical current density ($J_C$) of $1.15\;MA/cm^2$ at 77.3K in the self-field could be obtained from $1\;{\mu}m$ thick YBCO CC, fired at $740^{\circ}C$ for 3.5 h, implying that high performance YBCO CC is producible on IBAD MgO template. Further enhancement of $J_C$ values is expected by improving the in-plane texture of $CeO_2$-buffer layer and avoiding the metal substrate contamination.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.08a
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• pp.63-71
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• 2004

Recently, a sheet forming process of Mg alloys is highlighted again due to increasing demand for Mg wrought alloys in the applications of casings of mobile electronics and outer-skins of light-weight transportation. Microstructure control is essential for the enhancement of workability and formability of Mg alloy sheets. In this research, AZ31 Mg alloy sheets were prepared by hot rolling process and the rolling condition dependency of the microstructure and texture evolution was studied by employing a conventional rolling mill as well as an asymmetric rolling mill. When rolled through multiple passes with a small reduction per pass, fine-grained and homogeneous microstructure evolved by repetitive dynamic and static recrystallization. With higher rolling temperature, dynamic recrystallization was initiated in lower reduction. However with increasing reduction per pass, deformation was locallized in band-like regions, which provided favorable nucleation sites f3r dynamic recrystallization. Through post annealing process, the microstructures could be transformed to more equiaxed and homogeneous grain structures. Textures of the rolled sheets were characterized by $\{0002\}$ basal plane textures and retained even after post annealing. On the other hand, asymmetrically rolled and subsequently annealed sheets exhibited unique annealing texture, where $\{0002\}$ orientation was rotated to some extent to the rolling direction and its intensity was reduced.

• Korean journal of food and cookery science
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• v.33 no.1
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• pp.1-8
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• 2017

Purpose: The aim of this study was to evaluate the quality characteristics of rice nutritional bars prepared by adding Chinese artichoke (CA) powder to the rice powder. Methods: CA rice nutritional bars were prepared with various levels of CA powder (0%, 5%, 10%, 15%, and 20%) and designated as CA0 (without CA powder), CA5, CA10, CA15, and CA20, respectively. The total phenolic content, DPPH free radical scavenging activity, moisture content, pH, baking loss rate, leavening rate, volume, color, texture analysis, and sensory evaluations of rice nutritional bars were performed. Results: The total phenolic content and DPPH free radical scavenging activity exhibited an increase with increase in the substitute amount of CA powder. The results showed that the pH of rice nutritional bars decreased in all sample groups as the content of CA powder increased. The volume of the sample group with CA powder was higher than that of CA0. As the content of CA powder increased, lightness of the rice nutritional bars crumbs decreased while redness and yellowness increased. The texture analysis of rice nutritional bars showed that hardness, gumminess, and chewiness were the highest in CA0 while springiness and cohesiveness were the lowest in CA0. With respect to characteristic intensity rating, the taste, flavor, and softness of rice nutritional bars increased with increasing amounts of CA powder. In terms of consumer acceptability, CA15 and CA20 received the highest scores with respect to texture. Conclusion: Therefore, the results of this study indicate that replacing 15% of the rice powder with CA led to an efficient enhancement in the antioxidant and nutritional values of rice nutritional bars as well as the sensory quality.

• Journal of Korean Society for Geospatial Information Science
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• v.8 no.1 s.15
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• pp.121-130
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• 2000

For the land-cover classification we have usually used imagery of the optical sensors only. But currently a number of the satellite with various sensors are operating and the availability of using the data acquired from them are increasing. SAR sensors, in particular, can produce additional informations on the land-cover which has not been available from optical sensors. On this study, I have applied the SAR Image to the SPOT XS image in the classification procedures, and analysed the classified results. In this procedure I have extracted texture informations from SAR intensity images, then applied both intensity and texture informations. From the accuracy analysis, overall accuracy are increased slightly when the SAR texture was applied. In case of the Built-up class the results showed higher accuracy than those of when only the SPOT XS image was used. From this result I can show that overall accuracy was increased slightly but the spatial distribution of classes was visibly improved.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.27 no.2
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• pp.83-90
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• 1997

This study was performed to demonstrate the effect of linear or nonlinear contrast enhancement on subtraction images. Three different textures were radiograped on dental film. The first radiograph was taken without the presence of an object. the second, which showed trabucular bone, was taken of the molar area of a human. the third radiograph was taken of the coronal part of molars. Each film was digitized into a 1312 x 1024 pixel x 8 bit depth matrix by means of a Nikon 35 mm film scanner(LS-3510AF, Japan) with fixed gain and internal dark current correction to maintain constant illumination. The scanner was interfaced to a Macintosh Le ill computer(Apple Computer, Charlotte, N.C) This resulted in three pairs of images, including different textures-plain, bone and enamel. Digital regular, linearly and nonlinearly enhanced subtraction was performed. Computer software was ,used to simulate lesions in the shape of a 2D-Gaussian curve on each of a pair of images. The each subtraction images were presented in a random sequence to two groups of 10 observers(students and dentists). ROC analysis was used to compare observer performance. The following results were obtained ; 1. All of LCE subtraction, equalized subtraction and regular subtraction images of plain texture were diagnosed the best by far. 2. The data revealed a siginificant LCE effect in both the student group and the expert group. 3. Clinical expertise was a helphul factor for the observers in this study.