• Journal of electromagnetic engineering and science
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• v.15 no.1
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• pp.44-52
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• 2015

A worst-case estimate of an envelope correlation coefficient (ECC) is obtained for small multiple-input multiple-output (MIMO) mobile antennas operating below 1 GHz. The worst-case estimate is numerically derived in this paper using spherical and exponential wave functions. The derived result confirms that the worst-case ECC can be easily obtained from the rotation angle between the radiation patterns of two MIMO elements, which are attained directly from the amplitude of 2D electric field patterns without any additional phase and polarization information. As a practical example, MIMO mobile antennas with different antenna element arrangements are compared to verify the validity of the proposed worst-case estimate. Moreover, based on these analyses, we also suggest an effective approach to reduce the ECC of a small MIMO mobile antenna operating below 1 GHz by properly locating the antenna elements to make the radiation patterns perpendicular to each other.

• Journal of Advanced Research in Ocean Engineering
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• v.1 no.1
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• pp.25-35
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• 2015

This study presents the analysis of relationship between ship speed and local ice load on the Korean Icebreaker ARAON. The relationship curves were made from the data obtained at two areas: the Arctic and the Antarctic; and for two operation condition: the icebreaking condition in sea ice trial and general operation in ice covered sea. The strain data were converted to the equivalent stress value, and the influence of ship speed on the local ice load was analyzed and compared each other. These analysis results are useful in working on a statistically valid hull design approach.

• Journal of electromagnetic engineering and science
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• v.13 no.1
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• pp.1-7
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• 2013

This paper proposes a metamaterial (MTM) absorber for 2.45 GHz band applications. The unit cell of the proposed absorber consists of an electric LC (ELC) resonator and a strip line, which are printed on opposite sides of the substrate. The ELC resonator comprises two split ring resonators (SRRs) and a connecting line with a resistor. The designed absorber exhibits an absorption of 94 % and a half-max bandwidth of 0.16 GHz at 2.45 GHz.

• Biomedical Science Letters
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• v.12 no.1
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• pp.49-52
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• 2006

To elucidate the effect of antioxidant complex containing $\beta-carotene$, vitamin E, vitamin C, Ginkgo Biloba leaf extract and selenium on oxygen :tree radical production and detoxification system, rats were fed normal diet and normal diet with antioxidant complex 0.1%, 0.3% and 0.5% for 3 weeks. Feed efficiency ratio, changes in body weight, weight gain and amounts of feces of rat are similar in four groups. Liver weight per body weight and hepatic lipid peroxide weight increased in 0.5% group. However, hepatic glutathione contents in all antioxidant complex added groups were significantly increased compare with normal control group. On the other hand, the activity of xanthine oxidase was a little increased due to the amounts of antioxidant complex. Superoxide dismutase and gutathione peroxidase activity of 0.1% antioxidant complex added group were increased about $10{\sim}20%$ in comparison to normal control group. These results suggest that the supplementation of antioxidant complex 0.1% to basal diet may reduce the hepatic damage caused by free radicals.

• Journal of Society of Preventive Korean Medicine
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• v.4 no.1
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• pp.91-103
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• 2000

This study was performed to find out characteristics of daily average medical charge of the inpatients of an oriental medical university hospital in TaeJeon. The sample of the study was 966 inpatients discharged from the 4 clinical departments of th hospital from January 1 to June 31, 1998. The major findings are as follows : 1. The average length of stay was 15.6 days in dept. of Internal Medicine, 16.9 in Acupuncture, 10.1 in Neuro-psychiatry and 24.3 in Physical therapy Daily average medical charge of the depart ments was 70,517 Won 62,011 Won, 82,750Won and 65,390 Won respectively. 2. The daily average medical charge of the departments was highest in the first day of admission. From the second day, it maintained a lower and relatively constant level, but showing slight fluctation in the latter halt of the hospital stay.

• Journal of the Chungcheong Mathematical Society
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• v.22 no.1
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• pp.89-99
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• 2009

Let $\mu$ be a finite positive Borel measure on the unit ball $B{\subset}\mathbb{C}^n$ and $\nu$ be the Euclidean volume measure such that ${\nu}(B)=1$. For the unit sphere $S=\{z:{\mid}z{\mid}=1\}$, $\sigma$ is the rotation-invariant measure on S such that ${\sigma}(S)=1$. Let $\mathcal{P}[f]$ be the invariant Poisson integral of f. We will show that there is a constant M > 0 such that $\int_B{\mid}{\mathcal{P}}[f](z){\mid}^{p}d{\mu}(z){\leq}M\;{\int}_B{\mid}{\mathcal{P}}[f](z)^pd{\nu}(z)$ for all $f{\in}L^p({\sigma})$ if and only if ${\parallel}{\mu}{\parallel_r}\;=\;sup_{z{\in}B}\;\frac{\mu(E(z,r))}{\nu(E(z,r))}\;<\;\infty$.

• Journal of Korea Society of Industrial Information Systems
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• v.19 no.2
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• pp.31-36
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• 2014

In this paper, we developed an intergrated piezoresistive temperature and humidity sensor using nano-technology, and evaluated the properties. In the measuring range from $20^{\circ}C$ to $80^{\circ}C$, output sensitivity of temperature was about 0.75mV/$1^{\circ}C$. Output sensitivity of humidity was about 1.35mV/10%(RH). Therefore, developed sensor suggests that it is possible applicable to the general residential environment.

• Corrosion Science and Technology
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• v.15 no.1
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• pp.1-5
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• 2016

Zinc ethyl silicate coatings containing multi walled carbon nanotubes (MWCNTs) were prepared, to which we added spherical and flake shaped zinc particles. The anti-corrosive effects of MWCNTs and zinc shapes on the zinc ethyl silicate coated carbon steel was examined, using electrochemical impedance spectroscopy and corrosion potential measurement. The results of EIS and corrosion potential measurement showed that the zinc ethyl silicate coated with flake shaped zinc particles and MWCNT showed lesser protection to corrosion. These outcomes were in agreement with previous results of corrosion potential and corrosion occurrence.

• Journal of Industrial Technology
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• v.1
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• pp.39-45
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• 1981

The typical characteristic shape of the Koryo inlaid celadon Maebyong was reviewed and the symmetry of S curve was analyzed by the method of geometric basis. The contours of Maebyongs sampled were drawn and divided with geometric rectangular proportion. The analytical results showed the static and dynamic symmetric of the vase and the ratios of height and base of the rectangles established for the analysis of their shapes were almost 1:1, 1:${\sqrt{2}}$ and 3:5(known as the Golden Ratio). The excellent beauty of the curve was principally caused by the balanced and harmonius division of the proportional rectangles. The contour line was developed along with the logarithmic spiral modified and introduced lately into the shape of Yi dynasty's liquor bottle.

• ETRI Journal
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• v.24 no.4
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• pp.259-269
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• 2002

Polymers are emerging as new alternative materials for optical communication devices. We developed two types of polymer-based devices for optical communications. One type is for ultra high-speed signal processing that uses nonlinear optical (NLO) polymers in such devices as electro-optic (EO) Mach-Z${\ddot{e}} $ hnder (MZ) modulators and EO 2${\times}$2 switches. The other is for WDM optical communications that use low-loss optical polymers in such devices as 1${\times}$2, 2${\times}$2, 4-arrayed 2${\times}$2 digital optical switches (DOSs) and 16${\times}$16 arrayed waveguide grating (AWG) routers. For these devices, we synthesized a polyetherimide-disperse red 1 (PEI-DR1) side chain NLO polymer and a low-loss optical polymer known as fluorinated polyaryleneethers (FPAE). This paper presents the details of our development of these polymeric photonic devices considering all aspects from materials to packaging.