• Journal of Surface Science and Engineering
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• v.41 no.5
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• pp.189-193
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• 2008

In this study, we carried out an investigation of the etching characteristics (etch rate, selectivity to $SiO_2$ and $HfO_2$) of TiN thin films in the $CH_4$/Ar inductively coupled plasma. The maximum etch rate of $274\;{\AA}/min$ for TiN thin films was obtained at $CH_4$(80%)/Ar(20%) gas mixing ratio. At the same time, the etch rate was measured as function of the etching parameters such as RF power, Bias power, and process pressure. The X-ray photoelectron spectroscopy analysis showed an efficient destruction of the oxide bonds by the ion bombardment as well as showed an accumulation of low volatile reaction products on the etched surface. Based on these data, the ion-assisted chemical reaction was proposed as the main etch mechanism for the $CH_4$ containing plasmas.

• Journal of the Korean Society for Heat Treatment
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• v.23 no.5
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• pp.269-276
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• 2010

This study has been carried out to the low temperature plasma nitriding treatment on the mechanical properties of stainless steel at temperature range between $400^{\circ}C$ and $500^{\circ}C$. It was found that there was precipitated to free CrN matrix below $400^{\circ}C$ and there was precipitated S-phase of STS 316L, ${\varepsilon}$-phase of STS 409L and ${\alpha}N$-phase of STS 420J2. STS 316L has formed relatively abundant CrN phase and ${\gamma}^{\prime}-Fe_4N$ phase at $500^{\circ}C$, alternatively STS 409L and STS 420J2 were more deeply nitrided than STS 316L at $500^{\circ}C$.

• Elastomers and Composites
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• v.35 no.1
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• pp.53-62
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• 2000

Zinc plated steel tire cords were treated with RF plasma polymerization coating of acetylene or butadiene in order to enhance adhesion to rubber compounds. Plasma polymerization was carried out as a function of plasma power, treatment tune and gas pressure. In order to maximize adhesion, argon plasma etching was performed, with carrier gas such as argon, nitrogen and oxygen, while the adhesion of tire cords was evaluated via TCAT. Best results were obtained from a combination treatment of argon etching (90 W. 10 min, 30 mTorr) and acetylene plasma polymerization coating (10 W, 30 sec, 30 mTorr) with argon carrier gas (25/5:acetylene/argon). These samples exhibited a pull out force of 285N which is comparable to that obtained from the brass plated tire cords (290N).

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.2
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• pp.44-48
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• 2008

According to increment of stage, the speed of changeable stage Carry-increment adder can be close to $O(\sqrt{2n})$ because the word length which is computed in stage can be lengthened by 1 bit. But the number of stage bits is increased, fan-out of carry which is inputted in stage is increased. So tile speed can be slow. This paper presents a new carry-increment adder design method to fix the number of fan-outs regardless of the number of stages. By layout simulation of 37-bit adder, the area can be Increased up to 40%, but speed improvement up to 75% can be achieved, by the proposed method, compared with a conventional method.

• Journal of Radiation Protection and Research
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• v.41 no.4
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• pp.328-332
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• 2016

Background: Boron Neutron Capture Therapy (BNCT) is a new radiation therapy. In BNCT, there exists some very critical problems that should be solved. One of the severest problems is that the treatment effect cannot be known during BNCT in real time. We are now developing a SPECT (single photon emission computed tomography) system (BNCT-SPECT), with a cadmium telluride (CdTe) semiconductor detector. BNCT-SPECT can obtain the BNCT treatment effect by measuring 478 keV gamma-rays emitted from the excited state of $^7Li$ nucleus created by $^{10}B(n,{\alpha})$ $^7Li$ reaction. In the previous studies, we investigated the feasibility of the BNCT-SPECT system. As a result, the S/N ratio did not meet the criterion of S/N > 1 because deterioration of the S/N ratio occurred caused by the influence of Compton scattering especially due to capture gamma-rays of hydrogen. Materials and Methods: We thus produced an arrayed detector with two CdTe crystals to test cross talk phenomenon and to examine an anti-coincidence detection possibility. For more precise analysis for the anti-coincidence detection, we designed and made a collimator having a similar performance to the real BNCT-SPECT. Results and Discussion: We carried out experiments with the collimator to examine the effect of cross talk of scattering gamma-rays between CdTe elements more practically. As a result of measurement the coincidence events were successfully extracted. Conclusion: We are now planning to carry out evaluation of coincidence rate from the measurement and comparison of it with the numerical calculations.

• Korean Journal of Veterinary Service
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• v.34 no.3
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• pp.209-216
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• 2011

This study carried out to investigate the pathogenic Streptococcus spp. isolated from respiratory tract of Thoroughbred in Jeju province. The specimens were collected from nasal mucosa using a culture swab from 113 Thoroughbred horses. Suspected colonies were selected onto blood and MacConkey agar plate, and identified by standard biochemical properties using Vitek 2 system and PCR method. In this study, we isolated S. equi (n=6), S. zooepidemicus (n=31), S. equisimilis (n=5), S. dysgalactiae (n=2), S. agalctiae (n=1), non identified ${\beta}$-hemolytic Streptococcus spp. (n=1) from Thoroughbred horses. In antimicrobial susceptibility test, it showed a high sensibility in the most of antimicrobial except for neomycin, streptomycin, spectinomycin, erythromycin and clindamycin. These results will provide the basic information to establish control measures for the treatment and prevention of respiratory disease by pathogenic Streptococcus spp. in Thoroughbred horses in Korea.

• Bulletin of the Korean Chemical Society
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• v.32 no.11
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• pp.3909-3913
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• 2011

In this paper we have carried out molecular dynamics simulations (MD) for model systems of liquid n-alkane oligomers ($C_{12}{\sim}C_{80}$) at high temperatures (~2300 K) in a canonical ensemble to calculate viscosity ${\eta}$, self-diffusion constants D, and monomeric friction constant ${\zeta}$. We found that the long chains of these n-alkanes at high temperatures show an abnormality in density and in monomeric friction constant. The behavior of both activation energies, $E_{\eta}$ and $E_D$, and the mass and temperature dependence of ${\eta}$, D, and ${\zeta}$ are discussed.

• Journal of the Korean Mathematical Society
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• v.55 no.5
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• pp.1103-1129
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• 2018

In this paper, we show several vanishing type theorems for p-harmonic ${\ell}$-forms on Riemannian manifolds ($p{\geq}2$). First of all, we consider complete non-compact immersed submanifolds $M^n$ of $N^{n+m}$ with flat normal bundle, we prove that any p-harmonic ${\ell}$-form on M is trivial if N has pure curvature tensor and M satisfies some geometric conditions. Then, we obtain a vanishing theorem on Riemannian manifolds with a weighted $Poincar{\acute{e}}$ inequality. Final, we investigate complete simply connected, locally conformally flat Riemannian manifolds M and point out that there is no nontrivial p-harmonic ${\ell}$-form on M provided that the Ricci curvature has suitable bound.

• Communications for Statistical Applications and Methods
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• v.15 no.4
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• pp.509-516
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• 2008

We derive the influence function on the coefficient of variation. Empirical influence function and Sample influence function are used to verify the validity of the derived influence function. To show the validity of the influence function, we carry out simulations with random samples from normal distribution $N(20,1^2)$ and $N(20,5^2)$, respectively. The simulation result proves that the derived influence function is very accurate in estimating changes in the coefficient of variation when an observation is deleted.

• Korea Journal of Hospital Management
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• v.15 no.4
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• pp.100-124
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• 2010

This work was researched by practical method in a subjectivity study accessible in-depth, in sloughing off old habit of functional quantity analysis about Reception Type on policy reception of public & health campaign. The perception pattern come out in this study were divided into four types in Q-methodology. The result is as follows ; it is that divided'1[(N=16): Policy Improvement Type], 2[(N=7) : Public-relation Utility Type], 3[(N=19): Financial-continuance Type], 4[(N=11) : Healthy-prevention Orientation Type]'. Like this, it found that is very different type all over. Hereafter, this study is to ascertain acceptance behavior about Reception Type on policy reception of public & health campaign ; to offer a developmental suggestion about it.