• Communications of the Korean Mathematical Society
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• v.11 no.1
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• pp.245-252
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• 1996

The relative Nielsen number N(f;X,A) was introduced in 1986. It gives us a better, and ideally sharp, lower bound for the minimum number MF[f;X,A] of fixed points in the homotopy class of the map $f;(X,A) \to (X,A)$. Similarly, we also can think about the Nielsen map $f:(X,A) \to (X,A)$. Similarly, we also can be think about the Nielsen root theory. In this paper, we introduce a relative root Nielsen number N(f;X,A,c) of $f:(X,A) \to (Y,B)$ and show some basic properties.

• Journal of the Optical Society of Korea
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• v.15 no.3
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• pp.252-263
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• 2011

In this work, for the first time, the quality of restoration in wide-field microscopy images after deconvolution was analyzed as a function of different Point Spread Functions using one deconvolution method, on a specimen of known size and on a biological specimen. The empirical Point Spread Function determination can significantly depend on the numerical aperture, refractive index of the embedding medium, refractive index of the immersion oil and cover slip thickness. The influence of all of these factors is shown in the same article and using the same microscope. We have found that the best deconvolution results are obtained when the empirical PSF utilized is obtained under the same conditions as the specimen. We also demonstrated that it is very important to quantitatively check the process' outcome using several quality indicators: Full-Width at Half-Maximum, Contrast-to-Noise Ratio, Signal-to-Noise Ratio and a Tenengrad-based function. We detected a significant improvement when using an indicator to measure the focus of the whole stack. Therefore, to qualitatively determinate the best deconvolved image between different conditions, one approach that we are pursuing is to use Tenengrad-based function indicators in images obtained using a wide-field microscope.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.2
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• pp.252-263
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• 1997

Steady-state two-dimensional natural convective heat transfer in horizontal cylindrical annuli was studied by solving the governing equations based on the primitive variables. Emphasis was put on the occurrence of the multiple solutions at a given set of parameter values, and on the determination of the bifurcation points at which those multiple solutions begin to branch out. The multicellular flow pattern from the results of melting process in an isothermally heated horizontal cylinder for high Rayleigh numbers, was used as initial guesses for the field variables. This was succeeded in new bifurcation point to tetracellular solutions for an identical set of parameter variables of previous works. The close examination of flow pattern transition around bifurcation point was also conducted. It was found that the mechanisms of flow transition are different depending on the critical Rayleigh number of bifurcation point.

• Advances in Traditional Medicine
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• v.9 no.3
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• pp.252-258
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• 2009

Shade-dried flowers of Sarcostemma brevistigma Wight Syn (SBF) belonging to Asclepiadaceae yielded a rare flavonol glycoside viz., Quercetin 5a prenyl, 3-O-glucosyl, 7-O-(4c-p-coumaroyl) neohesperidoside which were characterized based on chemical and spectral (including 2D NMR) studies. The ethyl acetate fraction of alcoholic concentrate (test sample) of flowers of this plant (SBF) was evaluated for its hepatoprotective and inhibition of lipid peroxidation activities to investigate the scientific basis of the traditional uses. The oral administration in varying doses viz., 125 and 250 mg/kg of aqueous suspension of SBF to rats for 7 days produced significant (P < 0.01) hepatoprotective effect comparable to that of standard drug silymarin. The SBF afforded good hepatoprotection against $CCl_4$ induced elevation levels of serum marker enzymes, serum bilirubin and liver weight. The free radical scavenging effects of SBF and flavonol glycoside (SA) were assigned by $Fe^{2+}$/ascorbate induction method (in vitro), which revealed the inhibition of lipid peroxidation. The SBF and SA showed prominent anti-lipid peroxidation activity ($IC_{50}$ about $\sim$180 mg/ml and 11.0 mg/ml respectively), which was comparable to standard drug curcumin ($IC_{50}$ about $\sim$8.25 mg/ml). Thus the hepatoprotective activity of SB could be correlated to the free radical scavenging property of the flavonol glycoside.

• Journal of Radiation Protection and Research
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• v.28 no.4
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• pp.327-335
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• 2003

The commercially available neutron survey meter, the REM500, which uses a tissue equivalent proportional counter (TEPC) and the self-constructed TEPC were used to determine the microdosimetric quantities of several neutron calibration fields at Korea Atomic Energy Research Institute (KAERI). Microdosimetric spectra, absorbed dose, dose equivalent as well as quality factor were derived and compared with several neutron fields which were produced by using the shadow objects to make neutron scattered and being used as a kind of realistic neutron calibration fields at KAERI. The response of REM500 as a function of mean energy was evaluated with these neutron fields using the counts measured and the predetermined reference value. The response of the self-made TEPC and the REM500 was compared using one of the neutron calibration filelds of a $^{252}Cf$ source. The reference quantities of scattered neutron calibration fields were determined using a Bonner Sphere (BS). The value of frequency-mean lineal energy, dose-mean lineal energy and quality factor of two $^{252}Cf$ sources (unmoderated and $D_2O$ moderated) were determined to check the differences in the reference neutron fields between KAERI and Pacific Northwest National Laboratory (PNNL, USA) and the results were in good agreement within 1%. It means that there is no big difference in dosimetric quantifies of neutron calibration fields of two laboratories.

• Journal of the Korean Ceramic Society
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• v.46 no.3
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• pp.249-252
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• 2009

Nanocrystalline ceria particles were prepared by using the ultrasonic spray pyrolysis method. The prepared ceria particles were found to be spherical and non-agglomerated by the SEM and TEM analyses. It was found that carrier gas influences the size and morphology. It was found that the air stream of carrier gas results in porous agglomerated structure of ceria abrasives, whereas solid nano-sphere can be obtained in a more oxidizing atmosphere.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06a
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• pp.251-252
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• 2012

본 논문은 기존 Legacy NAND의 성능을 향상시키기 위해 제안된 ONFI (Open NAND Flash Interface) NAND의 특성을 지원하는 컨트롤러를 구현하고, 실제 테스트 보드 제작 및 실험 환경을 구축하여 성능을 측정하였다. 그 결과 인터페이스 속도가 기존 Legacy NAND에 비해 약 6배 증가하였다. 또한 읽기 속도의 경우 약 3배의 성능 향상이 있었다.

• JSTS:Journal of Semiconductor Technology and Science
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• v.1 no.4
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• pp.248-252
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• 2001

A noble single-ended input, double-balanced mixer topology is proposed. The mixer incorporates the common-source amplifier input stage with inductive degeneration for impedance matching. The analysis based on simulations shows that the overall performance of the mixer is excellent and is adjustable by varying the input transistor size to give best characteristics for the given linearity specifications.

• Proceedings of the IEEK Conference
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• 2004.06a
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• pp.249-252
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• 2004

Recently, wireless repeater with interference rejection has been considered for the next generation repeater. In this paper, adaptive interference rejection module suppressing interference in the 3G band is proposed. A novel adaptive rejection scheme is proposed and it is partially implemented by FPGA devices.

• Bulletin of the Korean Chemical Society
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• v.25 no.2
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• pp.249-252
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• 2004

Cytochrome P450 (P450)/$O_2$/NADPH engender electron transfer reaction of N-benzyl-N-substituted benzylamines to yield corresponding radical cation 1 that is simultaneously converted into 2 and 3. Subsequently, expulsion of proton and hydroxylation yielding a-hydroxylamines are followed by formation of benzaldehydes and benzylamines.