• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.1850-1852
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• 2005

$SrTiO_3$ and $BaTiO_3$ sol-liquids and powders were prepared by the sol-gel method. $SrTiO_3/BaTiO_3$ heterolayered thin/thick films have been prepared on the $Al_2O_3$ substrates by screen printing and spin-coating method. The thin films were sintered at $750^{\circ}C$ in the air for 1 hour and the thick films sintered at $1325^{\circ}C$ in the air for 2 hours, respectively. The $SrTiO_3/BaTiO_3$ thin/thick films's structural and dielectric properties were investigated. Increasing the spin-coating times, (110), (200), (211) peaks of the $SrTiO_3$ were increased. The X-ray diffraction(XRD) patterns and SEM photographs indicated that the $SrTiO_3$ phase were formed in the surface of $BaTiO_3$ thick films. The average thickness of a $BaTiO_3$ thick films and $SrTiO_3$ thin films were $50{\mu}m$ and 400nm, respectively The dielectric constant and dielectric loss of the $SrTiO_3/BaTiO_3$ thin/thick films with $SrTiO_3$ coated 5 times were 1598 and 0.0436 at 10KHz.

• Microbiology and Biotechnology Letters
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• v.16 no.4
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• pp.293-296
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• 1988

Stability of spheroplasts prepared from Saccharomyces cerevisiae D-71, a thermophilic strain and Zygosaccharomyces rouxii SR-S, an osmotolerant strain were studied. Stability of spheroplast from Saccharomyces cerevisiae D-71 was highest in 0.8M KCI and 1.0M sorbitol ; that from Zygosaccharomyces rouxii SR-S was highest in 0.4M KCI and mannitol and that from both strains was less than 10% for sonic oscillation at 20Kc for 60 sec. In centrifugation at 10000 x g for 10 min., stability of spheroplast from Saccharomyces cerevisiae D-71 was 93% and that from Zygosaccharomyces rouxii SR-S was 84%. Breakage of spheroplast from Saccharomyces cerevisiae D-71 was 99% and that from Zygosaccharomyces rouxii SR-S was 55% for UV irradiation with 15W UV lamp at a distance of 20 cm for 60 min.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.30 no.1
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• pp.15-20
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• 2019

Background and Objectives : The goal of this study is to present a strategy for improving the self-regulation (SR) ability and facilitating the change of vocal behavior by applying voice therapy using the SR concept to the patients with vocal cord nodule and muscle tension dysphonia. Materials and Method : The subjects were 80 patients and 80 patients who were diagnosed with muscle tension dysphonia and vocal nodules. As a control group, the results were compared among patients with the same dysphonia without using SR strategies. The concept of SR before voice therapy was explained to the patients, and the treatment was divided into three stages according to the goal of voice therapy. The treatment stages consist of 1) skill acquisition, 2) habit formation, and 3) habit changes. voice therapy was performed by applying SR strategies such as goal implementation intentions and a less routine behavior. Patient's dropout rates were measured to compare the adherence of voice therapy. Results : Significant improvement was seen in all groups receiving voice therapy. However, in the group using the SR strategy, the voice analysis results showed a relatively low dropout rate of voice therapy. In the generalization confirmation stage, patients who applied SR concept showed better results. SR strategy did no longer be necessary to maintain newly adopted vocal behavior. Conclusion : The results of this study show that SR is one of the cognitive factors that can have a significant impact on the outcome of voice therapy, and also has a positive impact on the acquisition and generalization of new skills. A better understanding of SR and the development of therapeutic strategies using it will play an important role in solving voice problems in clinical settings.

• The Journal of Advanced Prosthodontics
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• v.11 no.1
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• pp.23-31
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• 2019

PURPOSE. To investigate and compare the surface roughness (SR), weight and height of monolithic zirconia (MZ), ceramometal (CM), lithium disilicate glass ceramic (LD), composite resin (CR), and their antagonistic human teeth enamel. MATERIALS AND METHODS. 32 disc shaped specimens for the four test materials (n=8) and 32 premolars were prepared and randomly divided. SR, weight and height of the materials and the antagonist enamel were recorded before and after subjecting the specimens to 240,000 wear-cycles ($49N/0.8Hz/5^{\circ}C/50^{\circ}C$). SR, height, weight, and digital microscopic qualitative evaluation were measured. RESULTS. CM ($0.23+0.08{\mu}m$) and LD ($0.68+0.16{\mu}m$) exhibited the least and highest mean difference in the SR, respectively. ANOVA revealed significance (P=.001) between the materials for the SR. Paired T-Test showed significance (P<.05) for the pre- and post- SR for all the materials. For the antagonistic enamel, no significance (P=.987) was found between the groups. However, the pre- and post- SR values of all the enamel groups were significant (P<.05). Wear cycles had significant effect on enamel weight loss against all the materials (P<.05). CR and MZ showed the lowest and highest height loss of 0.14 mm and 0.46 mm, respectively. CONCLUSION. MZ and CM are more resistant to SR against the enamel than LD and CR. Enamel worn against test materials showed similar SR. Significant variations in SR values for the tested materials (MZ, LD, CM, and CR) against the enamel were found. Wear simulation significantly affected the enamel weight loss against all the materials, and enamel antagonist against MZ and CM showed more height loss.

• Journal of Environmental Science International
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• v.28 no.6
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• pp.561-570
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• 2019

A zeolitic material (Z-Y2) was synthesized from Coal Fly Ash (CFA) using a fusion/hydrothermal method under low-alkali condition (NaOH/CFA = 0.6). The adsorption performance of the prepared zeolite was evaluated by monitoring its removal efficiencies for Sr and Cs ions, which are well-known as significant radionuclides in liquid radioactive waste. The XRD (X-ray diffraction) patterns of the synthesized Z-Y2 indicated that a Na-A type zeolite was formed from raw coal fly ash. The SEM (scanning electron microscope) images also showed that a cubic crystal structure of size $1{\sim}3{\mu}m$ was formed on its surface. In the adsorption kinetic analysis, the adsorption of Sr and Cs ions on Z-Y2 fitted the pseudo-second-order kinetic model well, instead of the pseudo-first-order kinetic model. The second-order kinetic rate constant ($k_2$) was determined to be $0.0614g/mmol{\cdot}min$ for Sr and $1.8172g/mmol{\cdot}min$ for Cs. The adsorption equilibria of Sr and Cs ions on Z-Y2 were fitted successfully by Langmuir model. The maximum adsorption capacity ($q_m$) of Sr and Cs was calculated as 1.6846 mmol/g and 1.2055 mmol/g, respectively. The maximum desorption capacity ($q_{dm}$) of the Na ions estimated via the Langmuir desorption model was 2.4196 mmol/g for Sr and 2.1870 mmol/g for Cs. The molar ratio of the desorption/adsorption capacity ($q_{dm}/q_m$) was determined to be 1.44 for Na/Sr and 1.81 for Na/Cs, indicating that the amounts of desorbed Na ions and adsorbed Sr and Cs ions did not yield an equimolar ratio when using Z-Y2.

• Journal of Radiation Protection and Research
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• v.41 no.1
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• pp.49-55
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• 2016

Background: For the purpose of baseline data collection and enhancement of environmental monitoring the distribution studies of $^{137}Cs$ and $^{90}Sr$ in the soil of Uljin province was performed and the relation between surface soil activities and soil properties (pH, TOC and median of the surface soil) was analyzed. Materials and Methods: For 14 spots within 10 km from the NPP surface soil samples were collected and soils for depth profile were sampled for 3 spots in April 2011. Using ${\gamma}$-ray spectrometry with HPGe detector, the concentrations of $^{137}Cs$ were determined and the concentrations of $^{90}Sr$ were measured by counting ${\beta}$-activity of $^{90}Y$ (in equilibrium with $^{90}Sr$) in a gas flow proportional counter. Results and Discussion: The concentration ranges of $^{137}Cs$ and $^{90}Sr$ were $<0.479-39.6Bq{\cdot}(kg-dry)^{-1}$ (avg. $7.51Bq{\cdot}(kg-dry)^{-1}$) and $0.209-1.85Bq{\cdot}(kg-dry)^{-1}$ (avg. $0.74Bq{\cdot}(kg-dry)^{-1}$) which were similar to the reported values from other regions in Korea. The activity ratio of $^{137}Cs$ to $^{90}Sr$ in surface soils was around 9.67, which is much bigger than the initial value of 1.75 for worldwide fallouts because of faster downward movement of $^{90}Sr$ after fallout than that of $^{137}Cs$. For depth profile studies soils were collected down to 40 cm depth for the locations of Deokgu, Hujeong and Maehwa. The $^{137}Cs$ concentration distribution of the first two showed maximum values at top soils and decreased rapidly in exponential manner, while $^{90}Sr$ showed two local maximum values for soils near top and about 30 cm depth. Through linear fittings between the $^{137}Cs$ and $^{90}Sr$ concentrations of surface soil and pH, TOC and median of the surface soil, the only probable relationship obtained was between $^{137}Cs$ and TOC (determination coefficient $R^2=0.6$). Conclusion: The concentration ranges of $^{137}Cs$ and $^{90}Sr$ in Uljin were similar to the reported values from other regions in Korea. The only probable relationship obtained between activities and soil properties was between $^{137}Cs$ and TOC.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.22 no.2
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• pp.78-83
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• 2012

The structural change and the electrical conductivity with Sr content in $La_{1-x}Sr_xMn_{0.8}Cu_{0.2}O_3$ (LSMCu) were studied. $La_{0.8}Sr_{0.2}MnO_3$ (LSM) and $La_{1-x}Sr_xMn_{0.8}Cu_{0.2}O_3$ ($0.1{\leq}x{\leq}0.4$) were synthesized by EDTA citric complexing process (ECCP). A decrease in the lattice parameters and lattice volumes was observed with increase of Sr content, and these results were attributed to the increasing $Mn^{4+}$ ions and $Cu^{3+}$ ions in B-site. The electrical conductivity measured from $500^{\circ}C$ to $1000^{\circ}C$ was increased with increase of Sr content in the $0.1{\leq}x{\leq}0.3$ composition range, and it was 172.6 S/cm (at $750^{\circ}C$) and 177.7 S/cm (at $950^{\circ}C$, the maximum value) in x = 0.3. The electrical conductivity was decreased in x = 0.4 because of the presence of the second phase in the grain boundaries. The lattice volume was contracted by increase of $Mn^{4+}$ ions and $Cu^{3+}$ ions in B-site according to increase of Sr content and the electrical conductivity was increased with increase of charge carriers which were involved in the hopping mechanism.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.1
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• pp.48-59
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• 2009

Next generation mobile communication system will have various access networks and provide seamless multimedia data service to mobile nodes. The WiNGS system, one of these access network, has superior RAT(Radio Access Technology) and network connectivity other than previous ones. In this paper, we propose link-layer SR-ARQ between mobile node and WAGW to solve packet re-ordering problem during handover. In the proposed scheme, we apply the adaptive timer at the SR-ARQ sender to reduce unnecessary packet retransmission during handoff and delayed NAK algorithm at the SR-ARQ receiver for delaying NAK response due to temporary out-of-sequenced frames. We evaluate the performance of the proposed scheme by implementing the new SR-ARQ protocol at the link-layer using ns-2 simulator, and show the handover performance is improved greatly by preventing unnecessary retransmission.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.11
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• pp.2007-2016
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• 2000

After kaolin clay was compulsorily contaminated with $Sr^{2+}$ ion. the remediation characteristics by electrokinetic method were analyzed. In the first experiment. NaCl solution was used as an electrolyte to raise the electric field strength. After remediation for 0.8 days. the pH of the cathode side of the soil column was elevated from 4.0 to 11.7. and thereby precipitation $Sr(OH)_2$, started to be formed in the side. Therefore. efficiency of soil remediation was reduced significantly and the 32% of total $Sr^{2+}$ ion in the column was decontaminated in 6.7 days. In the second experiment. ethanoic buffer was injected in the soil column and $CH_3COOH$ was continuously inputted in cathode reservoir to restrain the pH elevation. The pH of the cathode side of the soil column was only ascended from 4.0 to 6.0 in 3.8 days and $Sr(OH)_2$ was not formed. The 21% of total $Sr^{2+}$ in the soil column was decontaminated in 0.6 days. and the 33% of total $Sr^{2+}$ in 0.9 days. and the 84% of total $Sr^{2+}$ in 1.6 days. and the 92% of total $Sr^{2+}$ in 2.5 days. and the 97% of total $Sr^{2+}$ in 3.8 days. Meanwhile. the residual concentrations in the column calculated by the developed model were similar to those by experiment.

• The Korea Journal of Herbology
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• v.30 no.4
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• pp.81-88
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• 2015

Objectives : The aim of present study was to evaluate the beneficial effect of Scutellariae Radix (SR) and Scutellariae Radix EtOH-heated at 200℃ (SR200) using lipopolysaccharide (LPS) treated intestine of mice.Methods : Extract of SR and SR200 were orally administrated. Their effects were compared with vehicletreated LPS and normal groups. Subsequently, we measured reactive oxygen species (ROS) and nitric oxide in the serum and western blotting in the intestine.Results : The average weight in LPS treated (Vehicle) group was lowered significantly compare to that in non-treated normal group and this weight loss in the vehicle group was effectively prevented by the administration of SR and SR200 respectively. The increased oxidative stress biomarker levels such as reactive oxygen species (ROS) and nitric oxide (NO) in the serum was markedly decreased by treated with SR200. The decreased levels of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) induced by LPS injection were significantly restored by both SR and SR200 treatment. Moreover, increased inflammatory mediators and cytokines such as inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) in the LPS treated vehicle mice were significantly decreased through down-regulation c-JUN through reduction of oxidative stress.Conclusions : SR and SR200 could have benefit effect through down-regulation of abnormal oxidative stress in LPS induced intestine injury mice. Moreover, The anti-inflammatory activity of SR200 extract was better than SR extract in the LPS induced intestine injury mice.