• Journal of Welding and Joining
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• v.18 no.1
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• pp.97-103
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• 2000

Time series analysis results show the SVD is a candidate of on-line monitoring of welding penetration when the covariance matrix of a full penetration is used as a mapping function. As the reconstructed embedding vectors from the chaotic scalar time series are manipulated by the covariance matrix, the mapped tim series lie on a hyper-ellipsoid which the lengths of semi-axes are the squared eigenvalues of the covariance matrix in the case of full penetration. These visualize by two dimensional stroboscope views. The other cases like partial penetration, are different in the sense of sizes and shapes. Here we test two types of time series; the ion current and the X-ray. The ion current is better than the X-ray as an on-line monitoring signal, because the difference of the eigenvalue spectrum of the ion(between the pull penetration and partial penetration) is bigger than those of the X-ray.

• Journal of Conservation Science
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• v.27 no.3
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• pp.269-276
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• 2011

We have suggested effective P-XRF analysis method for pigment painting layer by calculating penetration depth of X-ray. This experiment calculated that X-ray generated from P-XRF was possible penetration until 1.17mm deep in the pigment painting. Based on the experimental results, analysis for eight color pigments on wall paintings in Ssanggyesa Main Hall, most pigments were painted traditional pigments. However pigments on recently restorated wall painting were used synthetic modern pigments.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.6
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• pp.150-157
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• 2002

In textured material, diffraction angle $2{\theta}$ usually shows a nonlinear relation against $sin^2{\psi}$ due to elastic anisotropy of crystals. SPHD and SPCD steel is cold-rolled carbon steel for automobile. The characteristics X-ray for stress measurement is Cr $K_{\alpha}\;and\;Mo\;K_{\alpha}$ characteristic X-ray. The $2{\theta}-sin^2{\psi}$ diagram under elastic strain seems to have a linear behavior using regression line of data but has a nonlinear behavior in distribution of data by Cr $K_{\alpha}$ characteristic X-ray. As the plastic strain of specimen increases, the nonlinearity of $2{\theta}$ with respect to $sin^2{\psi}$ increases remarkably. On the other hand, the diffraction angle $2{\theta}$ by Mo $K_{\alpha}$ characteristic X-ray shows a good linearity on $2{\theta}-sin^2{\psi}$ diagram under plastic strain as well as elastic strain. Therefore, this paper presents the measurement of residual stress in cold-rolled carbon steel for automobile using penetration depth of Mo $K_{\alpha1}$ characteristic X-ray and multiplicity factor of crystal diffraction plane.

• Journal of the Korea Institute of Military Science and Technology
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• v.18 no.5
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• pp.566-573
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• 2015

The most important factor for the penetration performance of shaped charge is the liner design. By designing the liner to have properties of both high jet tip velocity and long jet break-up time, the better penetration performance could be acquired. Usually it is very difficult to satisfy above two conditions simultaneously. In this study, the liner with the shape of ogive was developed to have relatively larger jet mass compared to the conventional trumpet liner. The designed shaped charge showed jet properties with high jet tip velocity and long jet break-up time by using ogive liner and wave shaper. A commercially available hydro-dynamic code AUTODYN-2D was used for numerical analysis of jet formation. The flash X-ray test and the static penetration test were conducted to verify the results of numerical analysis.

• Journal of Magnetics
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• v.13 no.3
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• pp.85-87
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• 2008

I report a simple method to correct the saturation effect in absorption spectra measured in total electron yield (TEY) mode. It does not require additional measurements of the X-ray penetration depth. In order to check the reliability of the method, X-ray magnetic circular dichroism (XMCD) spectra for polycrystalline Fe were measured at two different incident angles, and then processed with the method. The two resultant XMCD spectra were identical, and their sum rule analysis produced the ratios of orbital magnetic moment to spin magnetic moment, which were very close to the well-known value.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.370-373
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• 2009

X-ray lithography was employed to fabricate ITO-less high resolution sustain electrodes for plasma display panel (PDP). A polyimide film based X-ray mask and Xray sensitive Ag electrode paste were fabricated to check their effect on the patterning of Ag electrodes with less than 30 ${\mu}m$ in width. The X-ray lithographic method was found to be useful for the high resolution sustain electrode patterns due to the high penetration power and low scattering property of X-ray source.

• Journal of the Korea Institute of Military Science and Technology
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• v.18 no.5
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• pp.574-581
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• 2015

In this paper, the effect of high voltage current pulse against shaped charge jet was analyzed through the visualization of jet behavior using flash X-ray and comparison of depth of penetration(DOP) into RHA(Rolled Homogeneous Armor) witness plates. The behavior of jet particles has been acquired using a flash X-ray equipment when current pulse was applied into the metal jet of a shaped charge(SC) warhead. Typical results such as jet breakup and radial jet dispersion, which are due to electromagnetic pressure by current pulse, have been obtained. Dozens of penetration experiments using a shaped charge with 55 mm diameter were performed according to various combinations of major parametric variables such as electrode spacing, standoff distance from SC warhead to electrode, and charge voltage. Subsequently, interrelations between major parametric variables and DOPs into RHA were analyzed.

• Journal of radiological science and technology
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• v.11 no.2
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• pp.3-15
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• 1988

When X-rays were projected into a patient, there occured the phenomena such as penetration, absorption and scattering etc. The penetrating rays were recorded on films as X-ray image used for diagnosis but scattered rays caused the radiation hazard both to the patient, specialist and technicians. The soft tissue includes many organs which are sensitive to the radiation and in may occupy $40{\sim}50%$ of body weight. Therefore X-rays should be carefully projected to the patient and it is strongly recommended to analyse the distribution of X-rays, when ever the patient is exposed to X-rays. In this study, the distribution of X-ray according to the thickness, the radiation field and the tube voltages (kVp) in soft tissue, the following results were obtained: 1. Total transmitted rays which kept the step with X-ray tube voltage (kVp) increased in proportion to the increasing of X-ray tube voltage. 2. The scattered ray rate in the total transmitted ray was not significantly found with X-ray tube voltage. 3. The affecting factors of the scattered ray rate in total transmitted ray were shown through the radiation field and the thickness. 4. The dose of scattered ray by the angle was observed more in direction of primary ray ($0^{\circ}$) and back scattering ($160^{\circ}$) than in direction of $90^{\circ}$. 5. The more the distance from phantom to the patient should be less distribution of scattered ray.

• Journal of Veterinary Clinics
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• v.9 no.2
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• pp.373-390
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• 1992

To assay the fertilizing capacity of domestic animal spermatozoa by hamster test, semen were collected from 13 boars(Duroc. Landrace and Yorkshire) which had been proved to be fertile in the past. then, were preserved in BWW medium or in raw state at 18$^{\circ}C$ or at room temperature. The preserved semen were given each different treatment according to the experimental design and coincubated with zona-free hamster ova for 5 hours. The ova were stained by lacmoid and examined under phase contrast microscope to investigate the rates of ova bound with sperm(sperm binding). ova penetrated by sperm(penetration) and formation of a male pronucleus(pronucleus formation) and also numbers of both bound and penetrated sperm per ovum. Between BWW and TBM medium for boar sperm. no difference in the results of hamster test was obtained. The boar spermatozoa in BWW medium, BWW with caffeine, BWW with heparin, and BWW with both caffeine and heparin showed no difference in the results of hamster test. The boar spermatozoa in BWW medium containing both calcium and RSA showed considerably higher rates of sperm binding, penetration and pronucleus formation as well as higher numbers of both bound and penetrated sperm than those not containing calcium with or without BSA( p<0.01) and also the same results higher than that containing calcium without BSA( p< 0.05). The boar spermatozoa irradiated by X-ray(70 KVP, 20mA) for 3 seconds. then, maintained at 18$^{\circ}C$ for 18 hours showed considerably lower rate of sperm binding than all the other groups including the control and X-ray groups irradiated by smaller dose or maintained for shorter period(p<0.01), and also showed lower number of bound sperm than the other groups(p<0.01, p<0.05). All the control groups of both raw and diluted sperm in BWM medium showed higher rates of sperm binding, penetration and pronucleus formation as well as higher number of penetrated sperm than all the X-ray groups irradiated for 3 seconds(70KVP, 20mA) and maintained for either 3 or 18 hours (p<0.01, p<0.05). At the same time the control groups of diluted sperm showed considerably higher rates of sperm penetration and pronucleus formation than the control group of raw sperm( p<0.01). These results indicates that fertile boar sperm showed considerably lower rates In the results of hamster test, when incubated in the medium without calcium and irradiated by X-ray than when incubated in the medium with calcium and not irradiated by X-ray, respectively, to prove consequently that hamster test would be of great value in assaying the fertilizing capacity of boar spermatozoa.

• Journal of the Korean Wood Science and Technology
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• v.45 no.6
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• pp.836-845
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• 2017

Gravimetric method is usually used to evaluate air-dry density, which is governing physical or mechanical properties of wood. Although it had high evaluation accuracy, the method is time consuming process. Thus, this study was conducted to estimate air-dry density of wood with high accuracy by using polychromatic X-ray and digital detector as alternative of gravimetric method. To quantify polychromatic X-ray projection for evaluating air-dry density, Lambert-Beer's law with the integral value of probability function was used. The integral value was used as weighting factor in the law, and it was determined by conducting simple test at various penetration depths and tube voltage. Mass attenuation coefficient (MAC) of wood also calculated by investigating polychromatic X-ray projection according to species, penetration depth and tube voltage. The species had not an effect on change of MAC. Finally, an air-dry density of wood was estimated by applying the integral value, MAC and Lambert-Beer's law to polychromatic X-ray projection. As an example, the relation of the integral value (${\alpha}$) according to penetration depth (t, cm) at tube voltage of 35 kV was ${\alpha}=-0.00091t{\times}0.0184$ while the regression of the MAC (${\mu}$, $cm^2/g$) was ${\mu}=0.5414{\exp}(-0.0734t)$. When calculation of root mean squared error (RMSE) was performed to check the estimation accuracy, RMSE at 35, 45 and 55 kV was 0.010, 0.013 and $0.009g/cm^3$, respectively. However, partial RMSE in relation to air-dry density was varied according to tube voltage. The partial RMSE below air-dry density of $0.41g/cm^3$ was $0.008g/cm^3$ when tube voltage of 35 kV was used. Meanwhile, the partial RMSE above air-dry density of $0.41g/cm^3$ decreased as tube voltage increased. It was conclude that the accuracy of estimation with polychromatic X-ray and digital detector was quite high if the integral value and MAC of wood were determined precisely or a condition of examination was chosen properly. It was seemed that the estimation of air-dry density by using polychromatic X-ray system can supplant the gravimetric method.