• Journal of applied mathematics & informatics
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• v.39 no.5_6
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• pp.761-768
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• 2021

Let I be a nonzero ideal of a prime ring R and m, n are positive integers. If R admits a generalized derivation F satisfying F(x)ⁿF(y)^m - xⁿy^m = 0 for any y, x ∈ I, then F(x) = ax for any x ∈ R and a^m+n = 1, where a ∈ C, the extended centroid of R.

• Bulletin of the Korean Mathematical Society
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• v.58 no.6
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• pp.1377-1385
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• 2021

In this paper, we consider a general number system with a base m in order to determine if a positive integer x is prime. We show that the base m providing the most efficient test is the primorial p_n# when p_n# < x < p_n+1# and establish a necessary and sufficient condition for x in between consecutive primorials to be determined as a prime number.

• Journal of Oriental Neuropsychiatry
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• v.18 no.3
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• pp.1-14
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• 2007

The objective of tills study is to identify the difference of somatic characteristics between Hwa-Byung and Major Depression by comparing the pattern identification of Hwa-Byung group and Hwa-Byung with Major Depression group(double diagnosis) Method: According to Hwa-Byung Diagnostic Interview Schedule(HBDIS) and SCID, 17 patients as diagnosed Hwa-Byung and 20 patients as diagnosed Hwa-Byung with Major Depression group(double diagnosis) were recruited. and by depression scale like Hamilton Rating Scale for Depression(HRDS) & Montgomery-Asberg Depression Rating Scale(MADRS), we excluded patients complaining moderate & severe depression among Hwa-Byung group and excluded patients showing mild depression among Hwa-Byung with Major Depression group. After this evaluation, we analysed and compared the pattern identification of both groups by OMS-prime. Result: 1. There were no significant differences of demographic data between both groups. 2. In the result of 'analysis on pattern identification' for all participant used by OMS-prime, most frequent pattern was deficiency of Yin and Yang of the heart(49%). 3. In the result of 'analysis on most correlated pattern identification' used by OMS-prime, for Hwa-Byung group was deficiency of Yin and Yang of the heart(45%) and the next were disharmony of the liver and spleen (20%), generation of phlegm due to stagnation of Gallbladder(15%) deficiency of Qi and Yin of the heart(l0%), And for Hwa-Byung with Major Depression group(double diagnosis) was deficiency of Yin and Yang of the heart(53%), the next were generation of phlegm due to stagnation of Gallbladder(18%), and deficiency of Qi and blood of the heart(l2%), 4. In the result of 'analysis on significant pattern identification' used by OMS-prime, for Hwa-Byung group was deficiency of Yin and Yang of the heart(20%) and the next were disharmony of the liver and spleen(15%), generation of phiegm due to stagnation of Gallbladder(15%), deficiency of Qi and Yin of the heart(14%), And for Hwa-Byung plus Major Depression group(double diagnosis) was deficiency of Yin and Yang of the heart(18%), the next were deficiency of Qi and Yin of the heart(18%), deficiency of Qi and blood of the heart(l0%), generation of phiegm due to stagnation of Gallbladder(18%), Conclusion: Hwabyung is syndrome that have many different symptoms, but there is no difference between Hwa-Byung group and Hwa-Byung with Major Depression group(double diagnosis) on the side of symptoms. Therefore, Hwabyung could be a new model for research on depression in Korean.

• Progress in Medical Physics
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• v.27 no.4
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• pp.189-195
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• 2016

This paper aims to verify the clinical feasibility of a custom-made film created by a laser cutting tool for End-to-End (E2E) quality assurance in robotic intensity modulated radiation therapy system. The custom-made film was fabricated from the Gafchromic EBT3 film with the size of $8^{{\prime}{\prime}}{\times}10^{{\prime}{\prime}}$ using a drawing that is identical to the shape and scale of the original E2E film. The drawing was created by using a computer aided design program with the image file, which is obtained by scanning original E2E film. Beam delivery and evaluations were respectively performed with the original film and the custom-made film using fixed-cone collimator on three tracking modes: 6D skull (6DS), Xsight spine (XS), and Xsight lung (XL). The differences between total targeting errors of the original and custom-made films were recorded as 0.17 mm, 0.3 mm, and 0.17 mm at 6DS, XS, and XL tracking modes, respectively. This indicates that the custom-made film could yield nearly equivalent results to those of the original E2E film, given the uncertainties caused by distortions during film scanning and vibrations associated with film cutting. By confirming the clinical feasibility of a custom-made film for E2E testing, it can be expected that economic efficiency of the testing will increase accordingly.

• Journal of the Korean Society for Heat Treatment
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• v.4 no.3
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• pp.13-20
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• 1991

The present work was aimed to examine the variation of precipitations and mechanical properties by thermomechanical treatments (TMT) in Al-2.19 wt%Li and Al-2.0 wt%Li-0.11 wt%Zr alloys. This study was performed by TEM, SEM observation, DSC, electrical resistance measurement, hardness and tensile strength measurement. First peak of resistivity aged at $90^{\circ}C$ was caused by precipitation of ${\delta}^{\prime}$-precursor phase, and second peak was caused by precipitation of ${\delta}^{\prime}$ phase. According to this result, the precipitation process of Al-2.19 wt%Li alloy was as follow : $SSSS{\rightarrow}{\delta}^{\prime}$-precursor phase ${\rightarrow}{\delta}^{\prime}$ (Coherent ${\rightarrow}$ Semi-coherent) ${\rightarrow}{\delta}$. In a Al-2.0 wt%Li-0.11 wt%Zr ternary alloy, the first peak of resistivity was appeared at initial aging heat-treatment. It is result from exsistant of ${\delta}^{\prime}$-precursor phase. The effect acceleration in a binary alloy was not appeared and the over-aging ternary alloy was accelerated with increase of the reduction rate. It is caused by combination effect of ${\delta}^{\prime}$ and composite phase.

• The Pure and Applied Mathematics
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• v.4 no.2
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• pp.131-135
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• 1997

We give the relation between the semilattice congruence N and the set of prime ideals of the ordered $\Gamma$-semigroup M.

• Geomechanics and Engineering
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• v.11 no.6
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• pp.739-756
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• 2016

The shear strength reduction finite element method (SSRFEM) is a powerful tool for slope stability analysis. The factor of safety (FOS) of the slope can be easily calculated only through reducing effective cohesion (c′) and tangent of effective friction angle ($tan{\varphi}^{\prime}$) in equal proportion. However, this method may not be applicable to soil slope under wetting-drying cycles (WDCs), because the influence of WDCs on c′ and $tan{\varphi}^{\prime}$ may be different. To research the method of estimating FOS of soil slopes under WDCs, this paper presents an experimental study firstly to investigate the effects of WDCs on the parameters of shear strength and stiffness. Twelve silty clay samples were subjected to different number of WDCs and then tested with triaxial test equipment. The test results show that WDCs have a degradation effect on shear strength (${\sigma}_1-{\sigma}_3)_f$, secant modulus of elasticity ($E_s$) and c′ while little influence on ${\varphi}^{\prime}$. Hence, conventional SSRFEM which reduces c′ and $tan{\varphi}^{\prime}$ in equal proportion cannot be adopted to compute the FOS of slope under conditions of WDCs. The SSRFEM should be modified. In detail, c′ is merely reduced among shear strength parameters, and elasticity modulus is reduced correspondingly. Besides, a new approach based on sudden substantial changes in the displacement of marked nodes is proposed to identify the slope failure in SSRFEM. Finally, the modified SSRFEM is applied to compute the FOS of a slope example.

• The korean journal of orthodontics
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• v.22 no.1
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• pp.135-146
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• 1992

It was the purpose of this study to analyze and compare the mechanical properties of ortho dontic open coil springs. Four variable factors were presented - wire diameter (.008", .009", .010"), lumen size (.030", .032", .036"), arch wire size and shape (.016" round, $ .016^{{\prime}{\prime}}{\times}.022^{{\prime}{\prime}}$ rect.) and alloy type (HiT II, Elgiloy, Sentalloy). The total 104 specimens were divided into 13 groups, and compression test was performed on an Instron test machine. The load deflection curve of each open coil spring was obtained, from which, the load-deflection relations, stiffnesses, percent recoveries were computed statistically. The results were obtained as follows: 1. When the lumen size of the coil spring remained constant, stiffness and percent recovery increased as the wire diameter increased. 2. When the wire diameter of the coil spring remained constant, stiffness and percent recovery decreased as the lumen size increased. 3. The effect of size and shape of arch wire on the coil spring was not statistically significant. 4. In alloy types, stiffness was the greatest in HiT II (55.21), Elgiloy (42.61) and Sentalloy (7.74) in that order. Sentalloy exhibited superior percent recovery and long range of action.

• Journal of the Korean Society for Heat Treatment
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• v.7 no.1
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• pp.17-24
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• 1994

The evaluation and analysis of diffusivity of lithium for coarsening and coarsening kinetics of ${\delta}^{\prime}$ precipitate in Al-Li-Cu-Mg-Zr alloy aged at $170^{\circ}C$ have been investigated by transmission electron microscopy. With ageing time, ${\delta}^{\prime}$ precipitate coaesened to followed $\bar{\gamma}{\propto}t^{1/3}$ and coarsening kinetics was found to be obeyed to the Lifshitz-Slyozov-Wagner(LSW) theory and diffusivity of lithium for coarsening of ${\delta}^{\prime}$ precipitate in Al-Li-Cu-Mg-Zr alloy was obtained to be $5.85{\times}10^{-17}{\sim}1.53{\times}10^{-16}$ by experimental coarsening rate constant and various coarsening kinetic theory. Diffusivity of lithium measured by using various model but MLSW and Tsumuraya (VI) et al. model in Al-Li-Cu-Mg-Zr alloy is similar to that calculated by the Costas's diffusivity equation. It was, therefore, suggested that additing to the Cu, Mg and Zr element in Al-Li system have no great effect on diiffusivity of lithium for coarsening of ${\delta}^{\prime}$ This suggest that in matrix.

• Nuclear Engineering and Technology
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• v.50 no.3
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• pp.462-469
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• 2018

The background spectrum of a $3^{{\prime}{\prime}}{\times}3^{{\prime}{\prime}}$ NaI(Tl) well-type scintillation SILENA detector was measured without shielding, in 6 cm thick lead shielding, and with 2 mm thick electrolytic copper covering the detector inside the lead shielding. The relative remaining background of the lead shield lined with copper was found to be ideal for low-level environmental radioactive spectroscopy. The background total count rate in the (20-2160 KeV) was reduced 28.7 times by the lead and 29 times by the Cu + Pb shielding. The effective reduction of background (1.04) by the copper mainly appeared in the energy range from X-ray up to 500 KeV, while for the total energy range the ratio is 1.01 relative to the lead only. In addition, a strong relation between the full-energy peak absolute efficiency and the detector well height was found using gamma-ray isotropic radiation point sources placed inside the detector well. The full-energy peak efficiency at a midpoint of the well (at 2.5 cm) is three times greater than that on the detector surface. The energy calibrations and the resolution of any single energy line are independent of the locations of the gamma source inside or outside of the well.