• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.5
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• pp.861-868
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• 2001

In this paper, the performance of Reed Solomon(RS)/convolution리 concatenated codes and turbo code using semi random interleaver over the radio communication channel was analyzed. In the result, we proved that the performance of decoder was excellent as increase the interleaver size, constraint length, and iteration number. When turbo code using semi random interleaver and Hsiconvolutional concatenated codes was constant constraint length L=5, BER=10-4 , each value of $E_b/N_o$ was 4.5〔dB〕 and 2.95〔dB〕. Therefore, when the constraint length was constant, we proved that the performance of turbo code is superior to RS/Convolutional concatenated codes about 1.55〔dB〕 in the case of BER=10-4.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.58 no.4
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• pp.345-351
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• 2022

In this study, the target strength for multi-frequency (38 kHz, 120 kHz, 200 kHz) of juvenile silverfish (Pleuragramma antarcticum) was estimated using by the KRM (Kirchhoff-ray mode) model. The body shape of the silverfish was described by a picture and the body length of nine individuals ranged in 1.8 cm to 8.8 cm. The maximum TS_cm according to the total length for the constant term (b20) was -92.93 dB at 38 kHz, -86.63 dB at 120 kHz, and -85.89 dB at 200 kHz, respectively. The averaged TS_cm according to total length for the constant term (b20) was -100.0 dB at 38 kHz, -93.0 dB at 120 kHz, and -106.9 dB at 200 kHz, respectively.

• Korean Journal of Clinical Pharmacy
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• v.6 no.2
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• pp.14-18
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• 1996

This study was attempted to investigate the dissolution rate and the bioavailability after oral administration of commercially available norfloxacin tablets in rabbits. The dissolution test was conducted in artificial gastric juice using basket method with for norfloxacin preparations (A, B, C and D) which were chemically equivalent. The results were as follows ; The dissolution rate was increased in the order of four different brand A>D>B>C. Area under the plasma concentration curve and peak plasma concentration were increased in the order of brand A>D>B>C. Absorption rate constant and peak time were increased in the order of brand B>A>C>D, and there was a little difference in elimination rate constant and biological half-life. The correlation of the dissolution rate and relative bioavailability showed significant linear relationship. From the results of this experiment, the bioavailability of norfloxacin tablets in rabbits may be predicted from the results of dissolution rate studies.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.3
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• pp.38-46
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• 1996

The purpose of this study is to develop the miniaturized duplexer filter for mobile communications using high dielectric constant (${\varepsilon}$r > 100, 180) ceramic resonators. Duplexer filter was ocmposed of ceramic resonators which has been developed using BNT system and SCT system, respectively. Developed duplexer filter was formed to have Tx frequency band at 836.5 (($\pm$12.5)MHz and Rx frequency band at 881.5 ($\pm$12.5)MHz. Insertion loss at Tx frequency band was 1.41dB and 1.46dB, insertion loss at Rx frequency band was 3.49dB and 3.65dB, respectively. Especially, duplexer filters using dielectric cermaics with ${\varepsilon}$r = 180 were 8% smaller than commercially manufactured duplexer filters using dielectric ceramics with ${\varepsilon}$r = 90 by murata.

• Journal of Environmental Science International
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• v.16 no.3
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• pp.255-260
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• 2007

The photocatalytic decolorization of Rhodamine B (RhB) was studied using packed-bed reactor and immobilized $TiO_2/UV$ System. The 20 W UV-A, UV-B and UV-C lamps were employed as the light source. The effect of shape and surface polishing extent of reflector, distance between the reactor and reflector, reactor material were investigated. The results showed that the order of the initial reaction constant with reflector shape was round > polygon > W > rhombus. The optimum distance between the reactor and reflector was 2 cm. The initial reaction constant of quartz reactor was 1.46 times higher than that of tile PVDF reactor.

• The Korean Journal of Ceramics
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• v.2 no.2
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• pp.76-82
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• 1996

PLZT ceramics having two nominal compositions, $Pb_{1-3x/2}La_xV_{x/2}(Zr_{03}Ti_{03})O_3$ and $Pb_{1-x}La_x(Zr_{0.2}Ti_{0.5})_{1-x/4}V_{x/4}O_3$ (V: vacancy) with x=0.00~0.30, were prepared. The physical, structural, and dielectric properties were investigated by X-ray diffraction, scanning electron microscopy, Raman spectroscopy, and measurements of bulk density and dielectric constant. The two series with A-stie and B-site vacancies showed different physical, structural, dielectric properties, and, specially, Curie temperature. In comparison to PLZT with B-site vacancies, PLZT with A-site vacancies showed high Curie temperatures and low maxima of dielectric constant. Consequently, it is evident that the properties of PLZT ceramics depend on the vacancy formula adopted as a batch composition in preparation.

• Honam Mathematical Journal
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• v.45 no.1
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• pp.123-129
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• 2023

In this paper, we introduce the reverse of the operator Davis-Choi-Jensen's inequality. Our results are employed to establish a new bound for the Furuta inequality. More precisely, we prove that, if $A,\;B{\in}{\mathcal{B}}({\mathcal{H}})$ are self-adjoint operators with the spectra contained in the interval [m, M] with m < M and A ≤ B, then for any $r{\geq}{\frac{1}{t}}>1,\,t{\in}(0,\,1)$ $A^r{\leq}({\frac{M1_{\mathcal{H}}-A}{M-m}}m^{rt}+{\frac{A-m1_{\mathcal{H}}}{M-m}}M^{rt}){^{\frac{1}{t}}}{\leq}K(m,\;M,\;r)B^r,$ where K (m, M, r) is the generalized Kantorovich constant.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.2
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• pp.68.4-68.4
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• 2019

In this poster, we present a relation between the Galactic foregrounds and Galactic latitude to study the structure of the Galactic foregrounds. We propose that the standard deviation of observed values along a line of sight with Galactic latitude b ('σ_l.o.s') is inversely proportional to ${\sqrt{sin{\mid}b{\mid}}}$. To confirm this, we use synchrotron intensity data from the Planck archive and rotation measure (RM) data from the NVSS. We divided the sphere of the Galactic coordinate into bins with a constant surface area and calculated the average of standard deviation along Galactic latitude ('σ_lat'). We compared σ_lat ${\sqrt{sin{\mid}b{\mid}}}$ with σ_lat along Galactic latitude and found that σ_lat ${\sqrt{sin{\mid}b{\mid}}}$ is the most constant. These results support that the relation is reasonable.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.9
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• pp.1058-1064
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• 2008

In this paper, we proposed a new hybrid interference canceller using the adaptive filter with Grouped CMA(Constant Modulus Algorithm)-LMS(Least Mean Square) algorithm in the RF(Radio Frequency) repeater. The feedback signal generated from transmitter antenna to receiver antenna reduces the performance of the receiver system. The proposed interference canceller has better channel adaptive performance and a lower MSE(Mean Square Error) than conventional structure because it uses the cancellation method of Grouped CMA algorithm. This structure reduces the number of iterations fur the same MSE performance and hardware complexity compared to conventional nonlinear interference canceller. Namely, MSE values of the proposed algorithm were lower than those of LMS algorithm by 2.5 dB and 4 dB according to step sizes. And the proposed algorithm showed fast speed of convergence and similar MSE performance compared to VSS(Variable Step Size)-LMS algorithm.

• Journal of the Korean Ceramic Society
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• v.34 no.2
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• pp.123-130
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• 1997

In this study, (Sr.Pb.Ca)TiO3-Bi2O3.3TiO2(SPCT) systems were investigated to develop a new material which has a high dielectric constant, a low dielectric loss and a small TCC(Temperature Coefficient of Capa-citance), and are suitable for high voltage applications as a function of the additions of Bi2O3.3TiO2 from 5 mol.% to 9 mol.%. The result obtained from our investigation showed that up to 6 mol.% Bi2O3.3TiO ad-dition the dielectric constant increased and it deteriorated at higher concentrations with increasing amount of the acicular grains. As a result of some dopants (SiO2, Nb2O3, MnO2) addition to SPCT, the specimens with MnO2 showed good dielectric properties. The dielectric constant decreased, but the TCC was improved with the addition of MnO2 from 0.15 wt.% to 0.45 wt. %.