• Imaging Science in Dentistry
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• v.31 no.1
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• pp.1-7
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• 2001

Purpose : To evaluate the usefulness of the reconstructed 3-dimensional image on the personal computer in comparison with that of the CT workstation by quantitative comparison and analysis. Materials and Methods : The spiral CT data obtained from 27 persons were transferred from the CT workstation to a personal computer, and they were reconstructed as 3-dimensional image on the personal computer using V-works 2.0/sup TM/. One observer obtained the 14 measurements on the reconstructed 3-dimensional image on both the CT workstation and the personal computer. Paired Nest was used to evaluate the intraobserver difference and the mean value of the each measurement on the CT workstation and the personal computer. Pearson correlation analysis and % incongruence were also performed. Results: I-Gn, N-Gn, N-A, N-Ns, B-A, and G-Op did not show any statistically significant difference (p>0.05), B-O, B-N, Eu-Eu, Zy-Zy, Biw, D-D, Orbrd R, and L had statistically significant difference (p<0.05), but the mean values of the differences of all measurements were below 2 mm, except for D-D. The value of correlation coefficient y was greater than 0.95 at I-Gn, N-Gn, N-A, N-Ns, B-A, B-N, G-Op, Eu-Eu, Zy-Zy, and Biw, and it was 0.75 at B-O, 0.78 at D-D, and 0.82 at both Orbrd Rand L. The % incongruence was below 4% at I-Gn, N-Gn, N-A, N-Ns, B-A, B-N, G-Op, Eu-Eu, Zy-Zy, and Biw, and 7.18%, 10.78%, 4.97%, 5.89% at B-O, D-D, Orbrd Rand L respectively. Conclusion : It can be considered that the utilization of the personal computer has great usefulness in reconstruction of the 3-dimensional image when it comes to the economics, accessibility and convenience, except for thin bones and the landmarks which are difficult to be located.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.116-119
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• 2002

A different route to the synthesis of $Eu^{3+}$ - activated matrices such as $YAlO_{3}$ and $GdAlO_{3}$ and luminiscent properties of these compounds, were studied. The new route (Combustion method) consist of the redox reactions between the respective metal nitrates and urea in a preheated furnace at ${500^{\circ}C}$. The Phosphor thus obtained were then heated at ${1000^{\circ}C}$ for 2-3 hours to get better luminiscent properties. The incorporation of $Eu^{3+}$ activator in these phosphors were checked by luminiscence investigations. Scanning electron microscopy (SEM) studies were carried out to understand surface morphological features and the particle size. X-ray energy dispersive analysis (EDAX) was also performed for the qualitative analysis of the phosphors.

• Journal of the Korean Ceramic Society
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• v.42 no.6 s.277
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• pp.391-398
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• 2005

It is known that $BaMgAl_{10}O_{17}:Eu^{2+}(BAM)$ phosphors currently used have a serious thermal degradation problem. We screened $SrO-B_2O_3-P_2O_5$ system by a solution combinatorial chemistry technique in an attempt to search for a thermally stable blue phosphor for PDPs. A Quantitative Structure Activity Relationship (QSAR) was also obtained using an artificial neural network trained by the result fiom the combinatorial screening. As a result, we proposed a promising composition range in the $SrO-B_2O_3-P_2O_5$ ternary library. These compositions crystallized into a single major phase, $Sr_6BP_5O_{20}:Eu^{2+}$. The structure of $Sr_6BP_5O_{20}:Eu^{2+}$ was clearly determined by ab initio calculation. The luminescent efficiency of $Sr_6BP_5O_{20}:Eu^{2+}$ was 2.8 times of BAM at Vacuum Ultra Violet (VUV) excitation. The thermal stability was also good but the CIE color chromaticity was slightly poor.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.39-40
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• 2005

Ferroelectric Eu-substituted $Bi_4Ti_3O_{12}$ (BET) thin films with a thickness of 200 nm were deposited on Pt(111)/Ti/SiO$_2$/Si(100) substrate by means of the liquid delivery MOCVD system and annealed at several temperatures in an oxygen atmosphere. At annealing temperature above $600^{\circ}C$, the microstructure of layered perovskite phase was observed. The remanent polarization of these films increased with increase in annealing temperature. The remanent polarization values ($2P_r$) of the BET thin films annealed at $720^{\circ}C$ were $37.71{\mu}C/cm^2$ at an applied voltage of 5 V.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05a
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• pp.841-846
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• 1995

대전지역 토양에서 추출한 흄산(TJHA)과 Am(III), Eu(III)의 착물형성에 대한 안정도상수를 추출용매 di-2-ethylhexyl phosphoric acid와 희석제 toluene을 사용하여 용매추출법으로 구하였다. 이온강도가 0.1M NaCIO$_4$에서 TJHA의 총 carboxylate capacity를 직접 전위차적정법으로 분석한 결과 3.757 meq/g이고, apparent pKa는 5.15 이었다. TJHA와 Am(III) 및 Eu(III)의 조건부 안정도상수의 log$\beta$1 값과 log$\beta$2 값을 흄산의 이온화도 함수로 구한 결과, Eu-TJHA은 0.1M NaClO$_4$일때 log $\beta$1=5.948$\alpha$ + (6.83 $\pm$ 0.3) 및 log $\beta$2 = 5.687$\alpha$ + (10.44 $\pm$ 0.4)이며, Am-TJHA은 log$\beta$$_1$= 4.004 $\alpha$ + (6.96 $\pm$ 0.2) 및 log$\beta$$_2$= 3.719 $\alpha$ + (11.71 $\pm$ 0.2)이었다.

• Electronics and Telecommunications Trends
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• v.20 no.2 s.92
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• pp.103-114
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• 2005

EU가 채택한 "전자통신 규제 패키지"는 종래의 정보통신 산업구조가 수직통합형에서 인터넷 기술발전에 따라 물리적인 네트워크, 전송서비스, 콘텐츠로 층별로 세분화되어 가고 있는 현실을 반영한 새로운 규제체계로 평가할 수 있다. EU는 가맹 국가에대해 이 법령을 2003년 7월까지 국내법에 적용하도록 권고하였으나, 15개 회원국 가운데 이 기한까지 국내법화를 실시한 나라는 5개국에 불과한 실정으로, 여기에 대한유럽 위원회의 대응이 주목된다. 우리나라도 이 법령의 문제점을 감안하면서 현실에맞는 통신. 방송 융합을 위한 규제 법령을 조속히 정비해야 할 것으로 기대한다.

• Korean Journal of Poultry Science
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• v.37 no.1
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• pp.15-21
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• 2010

To investigate the effect of dietary supplementation of Acanthopanax senticosus (AS) and Eucommia ulmoides (EU) on antioxidant defense system in laying hens, a total of three hundreds sixty 20-wk old Hyline brown commercial laying hens were assigned to five dietary groups for 10-wk: (1) control diet, (2) control diet supplemented with AS at 0.5%, (3) control diet supplemented with AS at 1.0%, (4) control diet supplemented with EU at 0.5% and (5) control diet supplemented with EU at 1.0%. Total antioxidant status (TAS) in blood and antioxidant enzymes including superoxide dismutase (SOD), gluthathione -S- transferase (GST) and glutathione peroxidase (GSH-Px), and lipid peroxidation in the small intestine and liver were measured. There were no changes in body weight for 10-wk dietary treatment. TAS in blood significantly (P<0.05) increased in birds fed the diet supplemented with 1% AS and 0.5 and 1.0% EU compared with those fed control diet. Especially, dietary EU showed much higher (P<0.05) TAS compared with AS. In the antioxidant defense enzymes, GST activity of the small intestine was shown to be significantly (P<0.05) increased in birds fed the diets supplemented with 0.5 and 1.0% EU compared with those fed the control diet. In addition, intestinal SOD activity significantly (P<0.05) increased in birds fed the diets supplemented with 0.5% of AS and EU. However, we could not observe any significant dietary treatment effect of those antioxidant parameters in the liver. In conclusion, dietary supplementation of 0.5% AS and EU in a laying hen diet could be applied as a potential antioxidant source to improves bio-activity of antioxidant and economical aspect in laying hens.

• Journal of the Korean Chemical Society
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• v.39 no.7
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• pp.508-512
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• 1995

A series of samples in the $Eu_{1-x}Sr_xCoO_{3-y}$ system has been prepared by heating the proper amount of reactant mixture to 1150$^{\circ}C$ under an ambient atmosphere, and the solid solutions are identified by X-ray powder diffraction analysis. The crystal system of samples for the compositions of x=0.00 and 0.25 are found to be orthorhombic whose local symmetry is similiar to the distorted octahedra with orthoferrite type one, whereas those of x=0.50 and 0.75 to be the cubic system, and that of x=1.00 to the orthorhombic similiar to be the brownmillerite type. The amount of $Co^{4+}$ ion (${\tau}$ value) is maximized at the composition of x=0.50, and the oxygen vacancies increase with the x value. The nonstoichiometric chemical formula of each compound could be determined from the mole ratio of $Co^{4+}$ ion and oxygen vacancies. The $Co^{3+}$ ion located in octahedral site has spin transition from low spin to high spin states with increasing temperature. Therefore, the effective magnetic moment of each samples obtained from the magnetic measurement is increased with the increasing temperature. The $EuCoO_{3.00}$ has strong antiferromagnetic interaction between the neighboring $Co^{3+}$ ions through the intermediate oxygen ions. With the increasing ${\tau}$ value, the absolute {\theta}_p$ value is decreased by the ferromagnetic interaction of $Co^{3+}-O^2-Co^{4+}$ and thus the {\theta}_p$ has positive value at x=0.50.

• Pediatric Infection and Vaccine
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• v.19 no.2
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• pp.55-60
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• 2012

Purpose: We conducted the immunoassay of pertussis according to ages, in order to evaluate protective immunity against pertussis in Korean populations. Methods: Healthy subjects were enrolled at four university hospitals in Korea. The subjects were grouped as seven age groups (every 10 years). Antibodies against pertussis toxin (PT) in sera were measured by enzyme linked immunosorbent assay (ELISA) kits. Geometric mean concentrations (GMC) of antibodies and the ratios of the subjects with seroprotective antibody levels were determined. The subjects with antibody titers ${\geq}24.0EU/mL$ were considered to seroprotective as the manufacturer's protocol. Results: Total 1,605 subjects (age: 2 months-65 years) participated in this study, and their GMC was $56.16{\pm}50.54EU/mL$. Among seven age groups, age group <11 year showed the highest GMC ($64.78{\pm}53.24EU/mL$) (P<0.001). In the analysis of the ratios of the subjects with seroprotective antibody titers, 68.2% of the subjects were proven to seroprotective, and age group <11 year also showed the highest ratio (76.5%) (P<0.001). Conclusions: We found that adolescences or adults (age group ${\geq}11$ year) showed lower levels of antibody against pertussis and lower ratio of the subjects with seroprotective antibody titers than children (age group <11 year).

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.3
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• pp.186-191
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• 2016

The effects of $Eu^{3+}$ doping on the structural, morphological, and optical properties of $MgMoO_4:Dy^{3+},Eu^{3+}$ phosphors prepared by solid-state reaction technique were investigated. XRD patterns exhibited that all the synthesized phosphors showed a monoclinic system with a dominant (220) diffraction peak, irrespective of the content of $Eu^{3+}$ ions. The surface morphology of $MgMoO_4:Dy^{3+},Eu^{3+}$ phosphors was studied using scanning electron microscopy and the grains showed a tendency to agglomerate as the content of $Eu^{3+}$ ions increased. The excitation spectra of the phosphor powders were composed of a strong charge transfer band centered at 294 nm in the range of 230~340 nm and two intense peaks at 354 and 389 nm, respectively, arising from the $^6H_{15/2}{\rightarrow}^6P_{7/2}$ and $^6H_{15/2}{\rightarrow}^4M_{21/2}$ transitions of $Dy^{3+}$ ions. The emission spectra of the $Mg_{0.85}MoO_4$:10 mol% $Dy^{3+}$ phosphors without incorporating $Eu^{3+}$ ions revealed a strong yellow band centered at 573 nm resulting from the $^4F_{9/2}{\rightarrow}^6H_{13/2}$ transition of $Dy^{3+}$. As the content of $Eu^{3+}$ was increased, the intensity of the yellow emission was gradually decreased, while that of red emission band located at 614 nm began to appear, approached a maximum value at 10 mol%, and then decreased at 15 mol% of $Eu^{3+}$. These results indicated that white light emission could be achieved by controlling the contents of the $Dy^{3+}$ and $Eu^{3+}$ ions incorporated into the $MgMoO_4$ host crystal.