• Proceedings of the Korean Nuclear Society Conference
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• 1996.05c
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• pp.111-116
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• 1996

IGSCC(Intergranular stress corrosion cracking) behaviors of Alloy 600 were studied by the electrchemical ten methods of controlling specimens electrode potentials in the active-passive transition region of anodic polarization curve. Anodic polarization and static potential tests of stressed C-ring type MA Alloy 600 were carried out in 10% NaOH at 300 $^{\circ}C$ for 7days. It was confirmed that IGSCC of Alloy 600 was accellerated by maintaining the specimen potential in the susceptible active-passive transition region of anodic polarization curve. An intergranular crack was initiated on the surface area of C-ring specimens where protective oxide layer was broken down. And the depth of the crack growth was about 100 ${\mu}$m during the testing periods.

• Progress in Superconductivity and Cryogenics
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• v.3 no.2
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• pp.1-4
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• 2001

For the practical use of a superconducting wire to magnet application, it is important to assess the Young modulus and other mechanical properties of HTS tapes. In order to establish a test method of mechanical properties for oxide composite superconductors. tensile tests of Bi-2223 multi- filamentary tapes were carried out at room temperature, as an activity of the International round robin test proposed by the committee of VAMAS/TWA 16-Subrgroup. The tapes consisting of mutli-filamentary showed a three stage tensile behavior. At the initial stage of the stress-streain curve. The elastic deformation existed in a quite nattrow strain region. But the plastic deformation was observed in a wide strain region due to the platic flow of the Ag alloy matrix. The results of RRT were also reported and discussed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.744-746
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• 2003

A ZnO varistor with reference voltage 250V/mm was fabricated through the control of particle size in slurry and the variation of sintering conditions. It was found that to measure the flatness of the V-I characteristic curve in the small-current region and the flatness of the V-I characteristic curve in a large-current region was improved nonlinearity of the fabricated ZnO varistor. According to the IEC 60099-4 was measured the accelerated aging test and high current test of the distribution class surge varistor which is excellent in respect to the property of ZnO varistor.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.31-36
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• 2003

In this study a relationship between SP curves and tensile properties was investigated by FE analysis on SP test with various assumed tensile properties. For the accuracy of FE analysis, SP test and tensile test were performed and those results were compared with FE analysis results. The yield load(Py) defined from the intersection point of two lines tangent to the elastic bending region and plastic bending region. And it was related specifically with yield stress(${\sigma}_0$) in FE analysis result curves. The slopes of FE analysis result curves normalized by yield stress(${\sigma}_0$) reflected the change of tensile properties regardless of yield stress(${\sigma}_0$) variation. Empirical relations were derived from these results. Tensile properties from these relations showed good agreement in FE analysis curve and tested curve.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.457-460
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• 1999

The effects of electrical positive stress on n-channel LDD and offset structured poly-Si TFT\`s have been systematically investigated in order to analyze the transfer curve\`s shift mechanism. It has been found that the LDD and offset regions behave as a series resistance that reduce the electric field near drain. Hot carrier effects are reduced because of these results. After electrical stress transfer curve’s shift and variation of the off-current are dependent upon the offset length rather than offset region’s doping concentration. Variation of the subthreshold slope is dependent upon offset region’s doping concentration as well as offset length.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.108-111
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• 2003

Currently, molecular devices are reported utilizing active self-assembled monolayers containing the nitro group as the active component, which has active redox centers[1]. We confirm the electrical properties of 4,4-di(ethynylphenyl)-2'-nitro-1-benzenethiolate. To deposit the SAM layer onto gold electrode, we transfer the prefabricated Au(111) substrates into a 1mM self-assembly molecules in THF solution. Au(111) substrates were prepared by ion beam sputtering method of gold onto the silicon wafer. As a result, we measured current-voltage curve using ultra high vacuum scanning tunneling microscopy (UHV STM), I-V curve also clearly shows several current peaks between the negative bias region (-0.3958V) and the positive bias region (0.4658V), respectively.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.4
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• pp.21-29
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• 2011

At existing skin detection methods using skin color information defined based on the prior knowldege, threshold value to be used at the stage of dividing the backround and the skin region was decided on a subjective point of view through experiments. Also, threshold value was selected in a passive manner according to their background and illumination environments in these existing methods. These existing methods displayed a drawback in that their performance was fully influenced by the threshold value estimated through repetitive experiments. To overcome the drawback of existing methods, this paper propose a skin region detection method using a histogram approximation based on the mean shift algorithm. The proposed method is to divide the background region and the skin region by using the mean shift method at the histogram of the skin-map of the input image generated by the comparison of the similarity with the standard skin color at the CbCr color space and actively finding the maximum value converged by brightness level. Since the histogram has a form of discontinuous function accumulated according to the brightness value of the pixel, it gets approximated as a Gaussian Mixture Model (GMM) using the Bezier Curve method. Thus, the proposed method detects the skin region by using the mean shift method and actively finding the maximum value which eventually becomes the dividing point, not by using the manually selected threshold value unlike other existing methods. This method detects the skin region high performance effectively through experiments.

• Journal of the Institute of Convergence Signal Processing
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• v.13 no.2
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• pp.70-76
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• 2012

In this paper, an automatic extraction method of glomerulus region from human renal tissue image is presented. The important information reflecting the state of kidneys richly included in the glomeruli, so it should be the first step to extract the glomerulus region from the renal tissue image for the further quantitative analysis of the renal condition. Especially, there is no clear difference between the glomerulus and other tissues, so the glomerulus region can not be easily extracted from its background by the existing segmentation methods. The outer edge of a glomerulus region is regarded as a common property for the regions of this kind ; a two- dimensional Gaussian distribution is used to convolve with an original image first and then the image is thresholded at this blurred image ; a closed curve corresponding to the outer edge can be obtained by usual pattern processing skills like thinning, branch-cutting, hole-filling etc., Finally, the glomerulus region can be obtained by extracting the area in the original image surrounded by the closed curve. The glomerulus regions are correctly extracted by 85 percentages and experimental results show the proposed method is effective.

• Journal of the Korean Ceramic Society
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• v.37 no.4
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• pp.359-367
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• 2000

Particulate composites of Al2O3/SiC, Al2O3/ZrO2 and Al2O3/ZrO2/SiC have been fabricated to investigate their R-curve behaviors and toughening mechanisms. Al2O3 containing 30 vol% SiC particles of 3${\mu}{\textrm}{m}$ showed rising R-curve behavior owing to the strong crack bridging by SiC particles. The fracture toughness reached 9.1 MPa {{{{ SQRT {m} }} at the crack length of 1000${\mu}{\textrm}{m}$. On the other hand, ZrO2-toughened Al2O3 had a high flat R-curve since it rose steeply in the short crack region due to the well known transformation toughening. For Al2O3/ZrO2/SiC composites, the R-curve behavior was similar to that of Al2O3/SiC but with slightly higher toughness. The SiC particles in this composite decreased the amount of transformable tetragonal phase to reduce the effect of transformation toughening by 50%. It was also found that the fracture toughness of this composite with two different toughening mechanisms was markedly lower than that estimated by the simple addition of two contributions.

• Journal of the Korean Data and Information Science Society
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• v.17 no.1
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• pp.19-30
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• 2006

The purpose of this article is to develop a program for teaching Type I and Type II errors in one sample. In this program, the concepts of two errors are visually explained, and the probabilities of two errors are also visually displayed as the rejection region changes or the sample size changes. Also, in this program, the power curve and the operating characteristic curve are visually displayed in terms of the parameter value of interest.