• Biomedical Science Letters
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• v.12 no.4
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• pp.427-433
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• 2006

We investigated the effect of propolis on the activity of antioxidant enzymes in rat liver exposed by X-ray irradiation. The dosage of propolis showed the effect of lowering the concentration of superoxide anion in irradiated rat liver, suggesting that propolis has a significant role to remove superoxide anion as an antioxidant and/or by activating the antioxidant enzyme. The activities of superoxide dismutase (SOD) and glutathione reductase (GR), disturbed by X-ray irradiation, were restored in 30 days to normal status in the group which dosed propolis before X-ray irradiation. Interestingly, catalase (CAT) and glutathione peroxidase (GPOX) activities were highly increased with feeding propolis to rat compared to untreated group, whereas glutathione s-transferase (GST) activity was little affected. Taken together, it suggests that the propolis has a protective role in the rat liver cells against X-ray irradiation by increasing and recovering the activities of antioxidant enzymes.

• Journal of Welding and Joining
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• v.32 no.5
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• pp.1-6
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• 2014

This study aims at manufacturing SA welded API-X70 line-pipe with sour gas resistance. A pipe was manufactured by JCO bending process and SA welding using the API-X70 plate guaranteed HIC resistance. SA welded pipe was expanded in order to reduce the residual stress. The evaluation of a pipe for resistance to HIC and SSCC were performed by the RS D 0004 and RS D 0005 standards. For verification that a pipe has acceptable resistance to HIC, fullscale test was carried out. Results showed no cracking for the HIC and SSCC.

• Journal of Haehwa Medicine
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• v.24 no.2
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• pp.1-16
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• 2016

Objectives : This study was designed to evaluate various tools including C-spine X-ray for estimating cervical curvature and identify the effect of wooden pillow on patients diagnosed with straightening of cervical curvature. Methods : This study was carried out on 51 subjects who were encountered traffic accident suffering cervical pain and diagnosed with straightening of cervical curvature by X-ray. 51 subjects were divided into wooden pillow(experimental) group and conservative therapy(control) group. Visual analogue scale, neck disability index and lateral pictures were used and compared after treatment. C-spine AP., Lat. X-ray were used on admission day to calculate cervical curvature and scoliosis by various ways. Results : 4 different measurements of cervical curvature didn't show common results. Both wooden pillow(experimental) group and conservative therapy(control) group showed significant improvement in the visual analogue scale(VAS) and neck disability index(NDI) after hospital treatment. Comparison between center line pictured by lateral view and C-spine Lat. pictured by X-ray showed significant difference in cervical curvature. Lateral deviation of cervical vertebra showed lengthened distance between mastoid process and spinous process of C7. Conclusion : As a result of this research, I found out that various tools for calculating cervical lordosis could derive different results and C-spine AP., Lat X-ray could cause artificial cervical lordosis. According to visual analogue scale(VAS) and neck disability index(NDI) wooden pillow was not effective to reduce pain & disability caused by straightening of cervical curvature. Futhermore, correction effect of straightening of cervical curvature and scoliosis by wooden pillow was weak.

• Laser Solutions
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• v.8 no.3
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• pp.5-10
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• 2005

[ $InxGa_{1-x}P/GaAs$ ] structures were grown by chemical beam epitaxy(CBE), Pure phosphine($PH_3$) gases were used as group V sources. for the group III sources, TEGa, TmIn were used. $InxGa_{1-x}P$ epilayer was grown on SI-GaAs substrate and has a 1-${\mu}m$ thick. We have investigated the characteristics of $InxGa_{1-x}P$ by the photoreflectance(PR) spectroscopy, The PR spectrum of $InxGa_{1-x}P$ shows third-derivative feature whose Peaks Provide energy gap. The energy gap of $InxGa_{1-x}P$ has deduced composition x. From temperature dependance of PR spectra, temperature coefficient is $dEg/dT=-3.773{\times}10^{-4}$ eV/K, and Varshni coefficients $\alpha$ and $\beta$ values obtained $4{\times}10^4$ eV/K and 267 K respectively. Also, interaction $\alpha$B was 19.4 meV using the Bose-Einstein temperature relation, and $\Theta$ value related the average phonon frequency were 101.4 K. In particular, shoulder peak related to defects observed in PR signal that measured in temperature 82 K.

• Journal of the Korea Computer Industry Society
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• v.3 no.5
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• pp.641-652
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• 2002

In this paper, proposes Kerberos certification mechanism that improve certification service of PKINIT base that announce in IETF CAT Working Group. Bid to certificate other realm because search position of outside realm through DNS and apply X.509 directory certification system, acquire public key from DNS server by chain (CertPath) between realms by certification and Key exchange way that provide service between realms applying X.509, DS/DNS of PKINIT base. In order to provide regional services, Certification and key exchange between realms use Kerberos symmetric method and Session connection used Directory service to connection X.509 is designed using an asymmetric method. By efficient TGT (Ticket Granting Ticket) exchange and reusability of ticket, A Design of Kerberos system that have effect and simplification of certification formality that reduce overload on communication.

• Journal of the Korean Mathematical Society
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• v.47 no.5
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• pp.1097-1106
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• 2010

Let R be a commutative ring with identity, X the set of all nonzero, nonunits of R and G the group of all units of R. We will investigate some ring theoretic properties of R by considering $\Gamma$(R), the zero-divisor graph of R, under the regular action on X by G as follows: (1) If R is a ring such that X is a union of a finite number of orbits under the regular action on X by G, then there is a vertex of $\Gamma$(R) which is adjacent to every other vertex in $\Gamma$(R) if and only if R is a local ring or $R\;{\simeq}\;\mathbb{Z}_2\;{\times}\;F$ where F is a field; (2) If R is a local ring such that X is a union of n distinct orbits under the regular action of G on X, then all ideals of R consist of {{0}, J, $J^2$, $\ldots$, $J^n$, R} where J is the Jacobson radical of R; (3) If R is a ring such that X is a union of a finite number of orbits under the regular action on X by G, then the number of all ideals is finite and is greater than equal to the number of orbits.

• Journal of electromagnetic engineering and science
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• v.10 no.4
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• pp.309-315
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• 2010

A dual-band dual-polarized microstrip antenna array for an advanced multi-function radio function concept (AMRFC) radar application operating at S and X-bands is proposed. Two stacked planar arrays with three different thin substrates (RT/Duroid 5880 substrates with $\varepsilon_r$=2.2 and three different thicknesses of 0.253 mm, 0.508 mm and 0.762 mm) are integrated to provide simultaneous operation at S band (3~3.3 GHz) and X band (9~11 GHz). To allow similar scan ranges for both bands, the S-band elements are selected as perforated patches to enable the placement of the X-band elements within them. Square patches are used as the radiating elements for the X-band. Good agreement exists between the simulated and the measured results. The measured impedance bandwidth (VSWR$\leq$2) of the prototype array reaches 9.5 % and 25 % for the S- and X-bands, respectively. The measured isolation between the two orthogonal polarizations for both bands is better than 15 dB. The measured cross-polarization level is ${\leq}-21$ dB for the S-band and ${\leq}-20$ dB for the X-band.

• Korean Journal of Metals and Materials
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• v.48 no.1
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• pp.85-89
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• 2010

The plastic deformation behavior of magnesium alloy is affected simultaneously by deformation temperature and strain rate under warm and/or hot working conditions. The soundness of deformation of AZ31-xCa (x=0. 0.7, 2.0 wt.%) extrudes during compression was strongly affected by processing variables including deformation temperature, strain rate. compression-loading direction, which was related to the activation of available deformation systems. The deformation behavior of AZ31-xCa extrudes was also affected by Ca content, which was related to the change of the sort and fraction of second phase. The complex effects of deformation temperature and strain rate on the deformation behavior of AZ31-xCa extrudes during compression under various conditions could be successfully described by Zener-Hollomon parameter.

• Imaging Science in Dentistry
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• v.33 no.3
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• pp.187-193
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• 2003

Purpose: To compare the measurements of the mandible and the detectability of the mandibular canal on reformatted images using a newly developed 3-dimensional implant simulation program with traditionally used CT multiplanar reconstruction program and true measurements. Materials and Methods: Ten dry dog mandibles were used in this study. Occlusal templates for CT examination were fabricated and marked with gutta perch a at ten sites. Axial CT scans were taken and reconstructed using DentaScan (D group) and Vimplant program (V group), and each mandible was sectioned at the previously marked sites (R group). Maximum vertical height (H) and maximum width (W) of the mandible, the distances from buccal border of the mandibular canal to the most buccal aspect of the mandible (X), and the distance from the superior border of the mandibular canal to the alveolar crest (Y) were measured, and the mandibular measurements in each group were compared. Detectability of mandibular canal was evaluated using a 3-point scale in both V and D groups by three oral radiologists and compared. Results: H in the V group was slightly greater than that in the D group, and Wand X in the V group was slightly less than those in the D group. H in the V group was less than that in the R group, and Wand X in the V group was larger than those in the R group. The detectability of the mandibular canal did not show statistically significant differences between V and D groups. Conclusion: The results of the experiment show that the newly developed, inexpensive Vimplant/TM/ simulation program can be used as an alternative to the traditionally used, and more expensive CT multiplanar reconstruction program.

• Journal of Preventive Medicine and Public Health
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• v.10 no.1
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• pp.44-51
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• 1977

In order to determine values for the body weight by height groups for Korean adults men who are fully grown up 4,028 (30-39 age-group ; 2,318, 40-49 age-group 1,340, and 50-59 age group : 370) apparently healthy males subjects were randomly selected for the measurement of body weight by height groups. 1) The avergae body height and weight of Korean adult men were $168.3{\pm}4.6cm$ and $63.4{\pm}7.1kg$ in 30-39 age group, $167.7{\pm}4.7cm$ and $63.4{\pm}7.4kg$ in 40-49 age group, and $167.3{\pm}5.2cm$ and $63.3{\pm}8.0kg$ in 50-59 age group. 2) A correlation coefficient of r=+0.52(P<0.001) between body height and weight was found in 30-39 age group of 2,318 subject, r=+0.48(P<0.001) in 40-49 of 1,340 and r=+0.53(P<0.001) in 50-59 of 370 with the aid of there coefficients of linear regression equation body weight and height were established for male as follow; for 30-39 age group, Y(weight in kg)=0.81X(height in cm)-73.02, 40-49 age group, Y(weight in kg)=0.74X(height in cm)-61.82, 50-59g age-group, Y(weight in kg)=0.82X(height in cm)-73.83. 3) With the aid of above listed various equation standard values for body weight by height group, with over weighing and under weighing values were established. 4) Standard bodyweight of Korean was lower than those of American, Japanese and several other formulas for ideal body weight.