• Journal of applied mathematics & informatics
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• v.27 no.1_2
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• pp.49-58
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• 2009

For $1{\leq}k{\leq}r$, let ${\sigma}$($K_{r,r}$ - ke, n) be the smallest even integer such that every n-term graphic sequence ${\pi}$ = ($d_1$, $d_2$, ..., $d_n$) with term sum ${\sigma}({\pi})$ = $d_1$ + $d_2$ + ${\cdots}$ + $d_n\;{\geq}\;{\sigma}$($K_{r,r}$ - ke, n) has a realization G containing $K_{r,r}$ - ke as a subgraph, where $K_{r,r}$ - ke is the graph obtained from the $r\;{\times}\;r$ complete bipartite graph $K_{r,r}$ by deleting k edges which form a matching. In this paper, we determine ${\sigma}$($K_{r,r}$ - ke, n) for even $r\;({\geq}4)$ and $n{\geq}7r^2+{\frac{1}{2}}r-22$ and for odd r (${\geq}5$) and $n{\geq}7r^2+9r-26$.

• Fashion & Textile Research Journal
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• v.24 no.6
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• pp.686-693
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• 2022

The rapid development of the fashion industry in contemporary society has also caused various problems such as environmental pollution, material excess, and spiritual poverty. Accordingly, traditional Chinese Taoist aesthetics can solve the spiritual poverty that people are facing today, and the spiritual pursuit of returning to innocence. This study focuses on the works of first generation Chinese designer Ma Ke as an example to discuss the embodiment and application of Taoist aesthetics. The results are as follows: First, Ma Ke's works emphasize the value of handicraft through traditional handcrafting and natural fibers, which reflect the beauty of simplicity and the non-action of Taoist aesthetics. Second, the works acknowledge nature by using natural materials and retaining their original appearance, which embodies Taoist aesthetics of the beauty in non-action and living in harmony with nature. Third, the collections reflect a critical attitude toward the fashion industry and consumer culture by rethinking consumerism and advocating environmental protection, thus propagating the beauty in simplicity and the harmonious life with nature in Taoism aesthetics. In conclusion, Ma Ke's designs incorporating sustainability and handicraft exhibit the core features of Taoist aesthetics, including the beauty in simplicity, non-action, and living in harmony with nature while exploring the relationship between modernity and tradition, man and nature, and handicraft and fashion. This research can contribute to understanding Ma Ke's works in promoting critical thinking about the fashion industry through Taoist aesthetics.

• Journal of radiological science and technology
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• v.33 no.3
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• pp.179-184
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• 2010

A hard X-ray microscope system for obtaining images of nano-spatial resolution has been widely studied and requires monochromatic X-ray. A multilayer mirror of 84% reflectivity was designed to acquire tungsten characteristic X-ray of 8.4 keV from the white beam generated from an X-ray tube, and the C/W multilayer mirror of $50{\times}50\;mm$ size and 5.65 nm d-spacing was fabricated by the ion-beam sputtering system. The C/W multilayer had a uniformity of 99.5%, and the structure of the multilayer mirror was verified by a TEM image. The obtainable x-ray reflectivity for the C/W multilayer mirror at 8.4 keV was estimated from measuring the X-ray reflectivity using the copper characteristic X-ray of 8.05 keV. Monochromatic X-ray of 8.4 keV was generated by combining a X-ray tube, and the reflectivity and monochromaticity were 77.1% and 0.21 keV, respectively. Monochromatic X-ray generated from the combination of an X-ray tube and an C/W multilayer mirror has enough potential to use X-ray source for hard X-ray microscope system of laboratory size. If the C/W multilayer mirror of d-spacing of a few nanometers can be fabricated, monochromatic X-ray corresponded to 17.5 keV, molybdenum characteristic X-ray, can be obtained and applied to mammography in the medical application.

• Journal of the Korean Vacuum Society
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• v.1 no.2
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• pp.298-301
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• 1992

진공증착된 Al 다결정 박막에 질소이온을 25keV-50keV, 1 $\times$ 1014-2 $\times$ 1017ions/cm2로 주입하여 박막의 결정구조와 nitride의 형성을 TEM으로 측정하였다. N+2이 온을 에너지 25keV, dose 1 $\times$ 1014ions/cm2로 주입하면 fcc 구조의 Al 결정이 관찰되며, 40keV 이상의 에너지로 2 $\times$ 1017ions/cm2이상 주입하면 AlN이 형성됨을 확인하였다.

• Food Science and Preservation
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• v.18 no.6
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• pp.938-945
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• 2011

Epimedium koreanum Nakai is a wild herb commonly consumed in South Korea due to its beneficial health effects. In the present study, the antimutagenic and immunoactivities of extracts from E. koreanum Nakai containing different icariin quantities were investigated for food use. In the Ames test, both the water and ethanol extracts were found not to have a mutagenic effect on Salmonella typhimurium TA98 and TA100, respectively. The E. koreanum Nakai extracts showed over 80 and 90% antimutagenic effects on benzo(${\alpha}$)pyrene (B(a)P) in S. typhimurium TA98 and TA100, respectively. Moreover, all the extracts showed over 70% antimutagenicity on S. typhimurium TA98 and TA100 against 4-nitroquinoline-1-oxide (4NQO). The E. koreanum Nakai extract with ethanol showed strong antimutagenic activity, higher than that of the water extract and the sequenced KE9412, KE9408, and KE9405. In the immunomodulating activity test, the effect of E. koreanum Nakai on the B (Rhamos) and T (Jukat) cells were investigated. The immunoactivity results showed that the growth and viability of the B and T cells increased and were activated more in KE9405 (1.8 times), KE9408 (1.6 times), and KE9412 (1.32 times) in the water extracts, and least in KE9412 (1.74 times), KE9408 (1.52 times), and KE9405 (1.4 times) in the ethanol extracts. In the case of both the water and ethanol extracts ($500{\mu}g/mL$) from E. koreanum Nakai, the highest cell number of the human B (Rhamos) and T (Jukat) cells was observed on day 4 in KE9405 and KE9412, and on day 5 in KE9408. Based on the obtained results, the development of E. koreanum Nakai as a food material is recommended.

• Progress in Medical Physics
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• v.10 no.2
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• pp.73-81
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• 1999

Scatter correction for single photon emission computed tomography (SPECT) plays an important role to improve image quality and quantitation. The purpose of this study was to investigate three scatter correction methods using Monte Carlo simulation. Point source and Jaszack phantom filled with Tc-99m were simulated by Monte Carlo code, SIMIND. For scatter correction, we applied three methods, Compton window (CW) method, triple window (TW) method, and dual photopeak window (DPW) method. Point sources located at various depths along the center line within a 20-cm phantom were simulated to calculate the window ratios and corresponding scatter fractions by evaluating the polynomial coefficients for DPW method. Energy windows were located in W$_1$=92-125 keV, W$_2$=124-126 keV, W$_3$=136-140 keV, W$_4$=140-141 keV, and W$_{5}$=154-156 keV. The results showed that in Jaszack phantom with cold sphere and hot sphere, the TW gave the closest contrast and percentage recovery to the ideal image, respectively, while CW overestimated and DPW underestimated the contrast of ideal one. All three scatter correction methods showed an improved image contrast. In conclusion, scatter correction is essential for improving image contrast and accurate quantification. The choice of scatter correction method should be made on the basis of accuracies and ease of implementation.

• Korean Journal of Radiology
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• v.22 no.4
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• pp.502-512
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• 2021

Objective: To objectively and subjectively assess and compare the characteristics of monoenergetic images [MEI (+)] and polyenergetic images (PEI) acquired by dual-energy CT (DECT) of patients with breast cancer. Materials and Methods: This retrospective study evaluated the images and data of 42 patients with breast cancer who had undergone dual-phase contrast-enhanced DECT from June to September 2019. One standard PEI, five MEI (+) in 10-kiloelectron volt (keV) intervals (range, 40-80 keV), iodine density (ID) maps, iodine overlay images, and Z effective (Z_eff) maps were reconstructed. The contrast-to-noise ratio (CNR) and the signal-to-noise ratio (SNR) were calculated. Multiple quantitative parameters of the malignant breast lesions were compared between the arterial and the venous phase images. Two readers independently assessed lesion conspicuity and performed a morphology analysis. Results: Low keV MEI (+) at 40-50 keV showed increased CNR and SNR_{breast lesion} compared with PEI, especially in the venous phase ([CNR: 40 keV, 20.10; 50 keV, 14.45; vs. PEI, 7.27; p < 0.001], [SNR_{breast lesion}: 40 keV, 21.01; 50 keV, 16.28; vs. PEI, 10.77; p < 0.001]). Multiple quantitative DECT parameters of malignant breast lesions were higher in the venous phase images than in the arterial phase images (p < 0.001). MEI (+) at 40 keV, ID, and Z_eff reconstructions yielded the highest Likert scores for lesion conspicuity. The conspicuity of the mass margin and the visual enhancement were significantly better in 40-keV MEI (+) than in the PEI (p = 0.022, p = 0.033, respectively). Conclusion: Compared with PEI, MEI (+) reconstructions at low keV in the venous phase acquired by DECT improved the objective and subjective assessment of lesion conspicuity in patients with malignant breast lesions. MEI (+) reconstruction acquired by DECT may be helpful for the preoperative evaluation of breast cancer.

• Journal of Radiation Protection and Research
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• v.10 no.1
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• pp.14-28
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• 1985

The development of mono energetic photon sources using $K_{\alpha}$ fluorescence X-ray of pure material was carried out in the energy range below 100 keV. The monoenergetic photons are very useful in the calibration of the radiation measuring instruments and can be produced as the $K_{\alpha}$ fluorescence X-ray by irradiating the bremsstrahlung to the thin pure metal foils called ‘radiators’. In this experiment, several radiators such as $_{47}Ag,\;_{50}Sn,\;_{68}Er,\;_{70}Yb,\;and\;_{82}Pb$ provide the wide monoenergetic photon energy ranging from 20 keV to 80 keV. By the spectrometry with HpGe LEPS, spectral purity factors which measure the monochrometicity for the $K_{\alpha}$ fluorescence X-ray, were determined as $0.64{\sim}0.94$. Dosimetry for the purpose of the determination of the exposure rate with a 600cc thin window ionization chamber, which was calibrated by the standard free-air ionization chamber, was performed. Exposure rates ranging $8.3{\sim}232.5mR/h$ was obtained according to the $K_{\alpha}$ fluorescence X-ray energy for each radiator.

• Journal of Radiation Protection and Research
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• v.22 no.3
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• pp.143-151
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• 1997

As the pulse heights from a NaI(Tl) detector vary with the temperature of the measuring environment a significant change in temperature may affect the energy calibration of the spectrometer. The auto-adjustment of the channel corresponding to a pulse heights can be achieved by introducing an external reference source to compensate the temperature dependency of pulse heights, but unfavorable increases of the Compton continuum are caused due to the external source. In this study, the total absorption peaks dominant in the typical environmental gamma spectrum-239 keV from $^{212}Pb$, 351 keV from $^{214}Pb$, 1460 keV from $^{40}K$ and 2614 keV from $^{208}Tl$ for examples - were used as reference in the correction of energy calibration. With these peaks, the program to calibrate the energy of the s spectrum was developed using Microsoft Visual Basic language. The program developed here was applied to the environmental spectra measured at intervals of 30 minutes in the temperature range of from $-20^{\circ}C$ to $10^{\circ}C$ to demonstrate the validity and applicability. As a result of the test, the correction scheme appeared to be effective in the temperature changes encountered in the usual environment.

• Composites Research
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• v.27 no.1
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• pp.25-30
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• 2014

The actuation performance of an EADE (Electro-active dielectric elastomer) is studied as functions of thinner content, thickness and types of the dielectric elastomer such as natural (NR), acrylonitrile-butadiene (NBR), and silicon (KE-12) rubbers. With a decrease in elastomer thickness ($1{\rightarrow}0.5{\rightarrow}0.25{\rightarrow}0.1{\rightarrow}0.05$ mm) and an increase in thinner content ($0{\rightarrow}30{\rightarrow}50$ phr), the actuating displacement of KE-12 elastomer is increased, however their breakdown occurs at low voltage. For the same thickness (1 mm), the displacement of KE-12 elastomer shows a higher value (2.24 mm) compared to that of NR or NBR at the same applied voltage of 25 kV. The KE-12 has the lowest elastic modulus and the NBR has the highest one among the tested elastomers. However, the displacement of NBR elastomer is higher compared to that of NR because of high dielectric constant. It is found that the important factors of EADE actuator are a thickness, modulus and dielectric constant of the elastomer.