• Journal of the Korea Society of Computer and Information
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• v.18 no.8
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• pp.87-93
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• 2013

A baby-step giant-step algorithm divides n by n blocks that possess $m={\lceil}\sqrt{n}{\rceil}$ elements, and subsequently computes and stores $a^x$ (mod n) for m elements in the 1st block. It then calculates mod n for m blocks and identifies each of them with those in the 1st block of an identical elemental value. This paper firstly proposes a modified baby-step giant-step algorithm that divides ${\lceil}m/2{\rceil}$ blocks with m elements applying $a^{{\phi}(n)/2}{\equiv}1(mod\;n)$ and $a^x(mod\;n){\equiv}a^{{\phi}(n)+x}$ (mod n) principles. This results in a 50% decrease in the process of the giant-step. It then suggests a reverse baby-step giant step algorithm that performs and saves ${\lceil}m/2{\rceil}$ blocks firstly and computes $a^x$ (mod n) for m elements. The proposed algorithm is found to successfully halve the memory and search time of the baby-step giant step algorithm.

• Journal of the Korean Society of Radiology
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• v.15 no.5
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• pp.755-760
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• 2021

In this study, the shielding rate of major X-ray protective equipment used in the medical environment was calculated using X-ray spectrum data emitted from the diagnostic X-ray generator of The Institute of Physics and Engineering(IPEM) Report-78, and the applicability of radiation protection was investigated. Radiation shielding rates were calculated through reduction rates of air-kerma and total intensity for lead apron (0.3 mmPb), thyroid shield (0.5 mmPb), lead goggles (0.5 mmPb), and lead glass (1.8, 2.7, 3.3 mmPb) used for diagnostic X-ray protection. As a result, the shielding rate calculated as the air kerma reduction rate ranged from 96.31 to 100% at 80 kV, and 90.35 to 100% at 120 kV. In addition, the results of this calculation were well matched with the results of previous studies measuring the actual shielding rate, and it is expected that the X-ray spectrum data of IPEM Report-78 can be used for radiation protection.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4B
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• pp.421-426
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• 2006

The effect of initial concentration of ammonium ion ($N_0$) and active nitrifiers ($X_0$) on nitrification was examined by continuous monitoring of the ammonium removal rate. The concentration of the active nitrifiers in the culture sludge, measured by the oxygen uptake rate (OUR), was found to be 42.8% of the culture sludge. Experiments were carried out under different ratios of $N_0/X_0$, viz., 0.025 to 0.493. The results from this study show that the oxidation rate was similar under the same $N_0/X_0$ ratio despite different initial concentration of ammonium ion ($N_0$) and active nitrifiers ($X_0$). Moreover, the Contois kinetic expression which includes biomass concentration, was found to describe the mechanism behind nitrification process. The ammonium oxidation rate ($q_{Nmax}$) and half saturation constant per unit activated nitrifiers ($K_N{^{\prime}}$) were theoretically determined using the Contois expression. These values were found to be 4.32 gN/gVSS/day and 0.013 gN/gVSS respectively.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.3
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• pp.493-497
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• 1998

The synthesis of $Sr_{1-x}Eu_xAl_2O_4$ (x=0.005~0.2;mol%) phosphors and its properties of both photoluminescence and long-phosphorescent were investigated as a function of $Eu_2O_3$ composition. The peak wavelengths (520 nm) of phosphorescence spectra were found not to vary with the $Eu_2O_3$ composition (x) of $Sr_{1-x}Eu_xAl_2O_4$ crystals. Single phase of $SrAl_2O_4$ which determined by XRD and PL was obtained with the compositions of x<0.05 mol%. After the removal of light excitation (360 nm), the excellent after-glow characteristics of the phosphorescence were obtained with the $Eu_2O_3$ compositions of x<0.05 mol%, although the after-glow intensities for all phosphors vary exponentially with the times.

• Journal of Environmental Science International
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• v.20 no.7
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• pp.907-917
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• 2011

This study investigated the application of experimental design methodology to optimization of conditions of air-plasma and oxygen-plasma oxidation of N, N-Dimethyl-4-nitrosoaniline (RNO). The reactions of RNO degradation were described as a function of the parameters of voltage ($X_1$), gas flow rate ($X_2$) and initial RNO concentration ($X_3$) and modeled by the use of the central composite design. In pre-test, RNO degradation of the oxygen-plasma was higher than that of the air-plasma though low voltage and gas flow rate. The application of response surface methodology (RSM) yielded the following regression equation, which is an empirical relationship between the RNO removal efficiency and test variables in a coded unit: RNO removal efficiency (%) = $86.06\;+\;5.00X_1\;+\;14.19X_2\;-\;8.08X_3\;+\;3.63X_1X_2\;-\;7.66X_2^2$ (air-plasma); RNO removal efficiency (%) = $88.06\;+\;4.18X_1\;+\;2.25X_2\;-\;4.91X_3\;+\;2.35X_1X_3\;+\;2.66X_1^2\;+\;1.72X_3^2$ (oxygen-plasma). In analysis of the main effect, air flow rate and initial RNO concentration were most important factor on RNO degradation in air-plasma and oxygen-plasma, respectively. Optimized conditions under specified range were obtained for the highest desirability at voltage 152.37 V, 135.49 V voltage and 5.79 L/min, 2.82 L/min gas flow rate and 25.65 mg/L, 34.94 mg/L initial RNO concentration for air-plasma and oxygen-plasma, respectively.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.2
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• pp.278-285
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• 1998

It was known that the C-IC transition in the mixed crystal $(A_{1-x}A^'_x)_2ZnCl_4$ is smeared out with increasing x, which is attributed to the pinning effect of the doped A' ions. In this study, we introduce a new mixed crystal system $K_2Zn_{1-X}Co_XCl_4$, where doped Co ions do not destroy the orientation of the polarization in C phase and preserve the long range ordering of IC phase. We grew a series of mixed crystals $K_2Zn_{1-X}Co_XCl_4$ for x=0, 0.001, 0.005, 0.01, 0.05, 0.1, 0.3, 0.5, 0.7, 1 by the Czochralski method and investigated the real composition of the mixed crystals, structure and the change of the C-IC phase transition with increasing x by the thermal analysis.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.3
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• pp.358-363
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• 2008

The intracytoplasmic sperm injection (ICSI) procedure has recently been utilized to produce transgenic animals and may serve as an alternative to the conventional pronuclear microinjection in species such as pigs whose ooplasm is opaque and pronuclei are often invisible. In this study, the effects of sperm membrane disruption and electrical activation of oocytes on in vitro development and expression of transgene green fluorescent protein (GFP) in ICSI embryos were tested to refine this recently developed procedure. Prior to ICSI, sperm heads were treated with Triton X-100+NaCl or Triton X-100+NaCl+NaOH, to disrupt membrane to be permeable to exogenous DNA, and incubated with linearized pEGFP-N1 vector. To induce activation of oocytes, a single DC pulse of 1.3 kV/cm was applied to oocytes for $30{\mu}sec$. After ICSI was performed with the aid of a micromanipulator, in vitro development of embryos and GFP expression were monitored. The chemical treatment to disrupt sperm membrane did not affect the developmental competence of embryos. 40 to 60% of oocytes were cleaved after injection of sperm heads with disrupted membrane, whereas 48.6% (34/70) were cleaved without chemical treatment. Regardless of electrical stimulation to induce activation, oocytes were cleaved after ICSI, reflecting that, despite sperm membrane disruption, the perinuclear soluble sperm factor known to mediate oocyte activation remained intact. After development to the 4-cell stage, 11.8 (2/17, Triton X-100+NaCl+NaOH) to 58.8% (10/17, Triton X-100+NaCl) of embryos expressed GFP. The expression of GFP beyond the stage of embryonic genome activation (4-cell stage in the pig) indicates that the exogenous DNA might have been integrated into the porcine genome. When sperm heads were co-incubated with exogenous DNA following the treatment of Triton X-100+NaCl, GFP expression was observed in high percentage (58.8%) of embryos, suggesting that transgenic pigs may efficiently be produced using ICSI.

• The Journal of Advanced Prosthodontics
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• v.8 no.5
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• pp.404-410
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• 2016

PURPOSE. Considering the importance of retention in the success and long-term clinical service of fixed partial dentures (FPDs) as well as the existing controversy regarding the effect of GLUMA desensitizer on the retention of full metal crowns cemented with RelyX U200 self-adhesive cement, this study aimed to assess the effect of GLUMA desensitizer on the retention of full metal crowns cemented using RelyX U200. MATERIALS AND METHODS. In this experimental study, 20 sound human premolars were prepared; a 0.5 mm chamfer finish line was prepared above the cementoenamel junction. The teeth were randomly assigned to two groups: a desensitizer group (n = 10, treated with GLUMA desensitizer) and a control (n = 10, no surface treatment). Full metal crowns were fabricated of base metal alloy and had a ring. All crowns were cemented with RelyX U200 and subjected to retention test by using a universal testing machine. The data were analyzed using SPSS version 20 and independent t-test. RESULTS. The mean tensile bond strength was significantly higher in the GLUMA desensitizer group ($230.63{\pm}63.8N$) compared to the control group ($164.45{\pm}39.3N$) ($P{\leq}.012$). CONCLUSION. GLUMA desensitizer increases the tensile bond strength of RelyX U200 self-adhesive cement to dentin.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.3961-3965
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• 2012

Objective: To compare the clinical effects of concurrent radiochemotherapy with those of radiotherapy in treating locally advanced nasopharyngeal carcinoma (Stage III~IVa). Methods: A total of 95 patients suffering from nasopharyngeal carcinoma (Stage III~IVa) were divided into two groups: concurrent radiochemotherapy (Group CCRT, n=49) and radiotherapy (Group RT, n=46). The two groups were both delivered conventional fractionated radiotherapy, while Group CCRT also received three cycles of PF (DDP+5-Fu) or PLF (DDP+5-Fu+CF) chemotherapy. Results: The complete remission rate and total remission rate of Group CCRT were higher than those of Group RT ($X^2$=4.72~7.19, P<0.05). The one-year overall survival (OS) rate calculated by the life table method, was also higher than that of Group RT ($X^2$=4.24, P<0.05) as well as the 3-year OS rate, nasopharyngeal control rate and cervical lymph nodes' control rate ($X^2$=4.28~4.40, P<0.05). In addition, the 5-year OS and metastasis-free rates of Group CCRT were higher than those of Group RT and the differences were of statistical importance ($X^2$=3.96~8.26, P<0.05). However, acute toxicity was also obviously higher, the difference in gastrointestinal reactions being statistically significant ($X^2$=11.70, P<0.05). Conclusion: This study demonstrated that concurrent radiochemotherapy could improve the remission rate, overall survival rate and locally control rate. The toxicity of concurrent radiochemotherapy could be tolerated by the patients.

• Korean Journal of Materials Research
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• v.21 no.8
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• pp.439-443
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• 2011

The crystal structure and magnetic properties of a new solid solution type ferrite $(Fe_2O_3)_5-(Al_2O_3)_{3.4}-(Ga_2O_3)_{0.6}-SiO$ were investigated using X-ray diffraction and M$\"{o}$ssbauer spectroscopy. The results of the X-ray diffraction pattern indicated that the crystal structure of the sample appears to be a cubic spinel type structure. The lattice constant (a = 8.317 ${\AA}$) decreases slightly with the substitution of $Ga_2O_3$ even though the ionic radii of the Ga ions are larger than that of the Al ions. The results can be attributed to a higher degree of covalency in the Ga-O bonds than in the Al-O and Fe-O bonds, which can also be explained using the observed M$\"{o}$ssbauer parameters, which are the magnetic hyperfine field, isomer shift, and quadrupole splitting. The drastic change in the magnetic structure according to the Ga ion substitution in the $ (Fe_2O_3)_5(Al_2O_3)_{4-x}(Ga_2O_3)_xSiO$ system and the low temperature variation have been studied through a M$\"{o}$ssbauer spectroscopy. The M$\"{o}$ssbauer spectrum at room temperature shows the superpositions of two Zeeman patterns and a strong doublet. It shows significant departures from the prototypical ferrite and is comparable with the diluted ferrite. The doublet of spectrum at room temperature appears to originate from superparamagnetic clusters and also the asymmetry of the doublet appears to be caused by the preferred orientation of the crystallites. The M$\"{o}$ssbauer spectra below room temperature show various complicated patterns, which can be explained by the freezing of the superparamagnetic clusters. On cooling, the magnetic states of the sample were various and multi critical.