• Journal of the Korean Society for Aviation and Aeronautics
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• v.23 no.2
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• pp.69-74
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• 2015

We propose a rigorous and practical methodology to evaluate the performance of symbolic manipulation program such as Mathematica, Maple, and Maxima. First, we demonstrate an inverse method to construct the benchmark problems of an initial value problems. The benchmark problems associated with the discrete version of the Chebyshev polynomials provide a rigorous and objective measure to evaluate the performance of symbolic manipulation programs. We compare three symbolic manipulation programs, which are Mathematica, Maple and Maxima, using this methodology. The computation time, the used memory and the perturbation terms are chosen for comparison parameters.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.475-476
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• 2018

In this paper, we propose a method to measure the number of biofouling attached to underwater structures. This method measures the number of biofouling based on digital images captured in underwater. The number of biofouling was measured after correcting the image quality of underwater images for accurate population counting. In order to measure the number of biofouling, Maxima value in the image was found.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2382-2388
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• 2007

A series of dimethine cyanine dyes were synthesized in a fast, efficient and high yield by the condensation of quaternary salts with 1H-indole-3-carbaldehyde in the presence of piperidine under solvent-free microwave irradiation. The products were identified by 1H NMR, IR, UV-Vis spectra and elemental analysis. The absorption and fluorescence properties of these dyes were investigated both experimentally and theoretically. Calculations performed at a combination of time-dependent density functional theory (TD-DFT) and the polarizable continuum model (PCM) reproduced the π-π* type absorption bands of the dyes. Regression analysis was used for studying theoretical results of the absorption maxima in different solvents. Compared with experimental counterparts, estimated overall uncertainties in the absorption maxima were about ±2%.

• Publications of The Korean Astronomical Society
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• v.7 no.1
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• pp.155-166
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• 1992

We observed a total of 14 Mira variables as well as 4 late type variable stars for their SiO ${\nu}= 1$, J = 2 - 1 maser lines from April 1989 to November 1990 with the 13.7 m radio telescope at Daeduk Radio Astronomy Observatory. The maser intensity variations were the prime objective of the observations which well covered the periods of the variations. The origion of the variations were studied by comparing wi th those previousely measured in optical and infrared(IR) wavelengths and we confirmed that the intensity variations were in good correlation with those in V magnitude and IR intensity as previousely found in former investigators in general. However, for a few sources, we could find the missing maxima. The intensities themselves also were in good correlation with SiO ${\nu}\;=\;1$, J = 1 - 0 maser intensities observed in Yebes as expected. The good correlations indicate that the pumping source of the SiO maser is likely to be the IR emission in the masing regions and the "missing maxima" that are apparent in two particular sources are considered to relate wi th the strength of shocks arising from the eruptive mass-loss from central stars.

• Journal of The Korean Astronomical Society
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• v.44 no.3
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• pp.73-79
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• 2011

We collect 24 times of light maxima data from sources in the literature, unpublished data and open databases, and investigate the variations of the observed and calculated (O-C) values for light maxima of V1719 Cyg. We found no evidence of the variations in the (O-C) values. We estimate the effective temperature and surface gravity using both the Kurucz and MARCS/SSG grids for different metallicity values [A/H]=0.0 and +0.5 for V1719 Cyg. It is confirmed that the temperature is almost the same, but, in the case of surface gravity, the MARCS/SSG grid gives the value closest to that obtained from the period-gravity relation derived by using the pulsation-evolution theory. We obtain two spectra of V1719 Cyg from spectroscopic observation which permitted us to find the effective temperature and the surface gravity of the star directly. We estimate the metallicity and it is found that the abundance of iron is equal to the solar value.

• Journal of the Korean Chemical Society
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• v.6 no.2
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• pp.170-175
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• 1962

The ultraviolet and visable absorption spectra of trans, cis-azoxybenzene, substituted azoxybenzenes and their conjugate acids have been studied. The 320-350$m{\mu}$ main bands of free-base of azoxybenzenes are due to ${\pi}{\to}{\pi}^{\ast}$ transition. These bands of their conjugate acids shown bathochromic shift into visible range. The following emperical relationship between absorption maxima of the main bands was found. ${\lambda}_{max}={\lambda}^{\circ}_{max}+{\Delta}{\lambda}_x+{\Delta}{\lambda}_y$ This relationship in terms of wave number is also hold in good agreement. ${\nu}={\nu}_{\circ}-({\Delta}{\nu}_x+{\Delta}{\nu}_y)$

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.40 no.6
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• pp.1-9
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• 2003

In this paper, we propose a new fingerprint feature extraction method using the convex structure. A fingerprint minutiae flows along the uniform direction and is regarded as a sinusoidal signal across the normal direction. Local maxima of the signal represent coarse thinned one-pixel-wide ridges in which the convex region of the signal correspond to ridges. The proposed fingerprint feature extraction method detects the convex structure and local maxima. Finally fingerprint features are extracted from one-pixel-wide ridges. Because it has no parameter, it is efficient for various fingerprint identification systems.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.721-723
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• 2002

We report a new red light emitting fluorene-based copolymer, poly{9,9-bis(2'-ethylhexyl)fluorene-2,7-diyl-co-2, 5-bis(2-thienyl-1-cyanovinyl}-1-(2'-ethylhexyloxy)-4methoxybenzene-5",5'''-diyl} (PFTCVB). The synthesized copolymers showed the absorption maxima at about 380 nm and the absorption between 425 and 600 nm increased as the fraction of the thiophene-containing monomer (BTCVB) increased. In PL, the emission maxima of the copolymers were red-shifted as the fraction of BTCVB increased, despite the similar absorption characteristics were shown in the UV-visible spectra. The copolymer containing 15 mol% of BTCVB showed a maximum PL and EL emission at 620 and 630 nm.

• Bulletin of the Korean Chemical Society
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• v.35 no.2
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• pp.448-456
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• 2014

A series of seven Ru(II) complexes bearing NHC ligands have been synthesized. The electronic structures of these complexes were analysed by spectroscopic and electrochemical methods and further examined by theoretical calculations. Data show that absorption maxima are dependent on the HOMO level rather than the HOMO-LUMO gaps.

• Journal of Applied Biological Chemistry
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• v.42 no.3
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• pp.151-153
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• 1999

Gromwell (Lithospermum erythrorhizon) pigment solution and Jindo Hongju prepared in the laboratory showed characteristic pH-dependent color changes and a shift in absorption maxima. This phenomenon was not observed in the solution of the artificial food colorant Red No. 2 which was suspected to be used in the manufacture of fake Jindo Hongju. A few fake products could be detected by using the pH-dependent shift in absorption maxima among the Jindo Hongju on market.