• Honam Mathematical Journal
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• v.41 no.1
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• pp.35-49
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• 2019

In this work, it is shown that the combination of operational techniques and the use of the principle of quasi-monomiality can be a very useful tool for a more general insight into the theory of matrix polynomials and for their extension. We explore the formal properties of the operational rules to derive a number of properties of certain class of matrix polynomials and discuss the operational links with various known matrix polynomials.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.14 no.2
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• pp.113-124
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• 2010

We consider matrix polynomial which has the form $P_1(X)=A_oX^m+A_1X^{m-1}+...+A_m=0$ where X and $A_i$ are $n{\times}n$ matrices with real elements. In this paper, we propose an iterative method for the symmetric and generalized centro-symmetric solution to the Newton step for solving the equation $P_1(X)$. Then we show that a symmetric and generalized centro-symmetric solvent of the matrix polynomial can be obtained by our Newton's method. Finally, we give some numerical experiments that confirm the theoretical results.

• Kyungpook Mathematical Journal
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• v.56 no.2
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• pp.387-396
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• 2016

An $n{\times}n$ matrix A over a commutative ring is strongly clean provided that it can be written as the sum of an idempotent matrix and an invertible matrix that commute. Let R be an arbitrary commutative ring, and let $A(x){\in}M_n(R[[x]])$. We prove, in this note, that $A(x){\in}M_n(R[[x]])$ is strongly clean if and only if $A(0){\in}M_n(R)$ is strongly clean. Strongly clean matrices over quotient rings of power series are also determined.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.4
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• pp.377-385
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• 2016

In order to investigate the possibility of Sesamum indicum L. (S. indicum) extract as an active ingredient for wrinkle-care cosmetics, we prepared 70% ethanolic extract of S. indicum and measured its elastase inhibitory activity and collagenase inhibitory activity. We also evaluated the effect of S. indicum extract on protein and mRNA expression of MMPs in fibroblast cell (CCD-986sk). For anti-wrinkle effects, elastase inhibition activities and collagenase inhibition activities were 37.8% and 45% at a dose of $1,000{\mu}g/mL$ of S. indicum 70% ethanol extract. For a cell viability test, measured on fibroblast cell by ethanol extract of S. indicum, results showed 96% with cell viability at $100{\mu}g/mL$ concentration. According to the results of western blot of ethanol extract from S. indicum the expression of the matrix metalloproteinase-1 (MMP-1), matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-3 (MMP-3) protein was decreased by 63%, 43%, 49% at $100{\mu}g/mL$ concentration. Reverse transcription-polymerase chain reaction (PCR) of ethanol extract from S. indicum showed that the expression of MMP-1, MMP-2, MMP-3 mRNA was decreased by 82%, 79%, 82% at $100{\mu}g/mL$ concentration. The findings suggest that 70% ethanol extract from S. indicum has potential as a cosmeceutical ingredient with anti-wrinkle effects.

• Journal of Photoscience
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• v.10 no.1
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• pp.165-173
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• 2003

m-Phenylene-linked biscarbenes, bisnitrenes and carbenonitrenes can be formed photochemically from appropriate nitrogenous precursors. Generation of such reactive intermediates under matrix-isolation conditions allows for their characterization by spectroscopic techniques such as ESR, UV /vis and IR. The latter method is also useful in characterizing secondary products derived from these reactive intermediates. Computational chemistry methods complement experimental IR data, aiding, thus, in identification of such compounds. In addition electronic structure calculations help in developing qualitative and semi-quantitative models, which can be useful in predicting ground-state multiplicities. The parent systems of m-phenylene-linked carbenes and nitrenes have high-spin ground states, but a switching to lower multiplicity can be achieved by chemical substitution. The ground state and various low-lying excited states of m-phenylenecarbenonitrenes can be reasonably approximated by simple valence-bond depictions. Finally, m-phenylenecarbenonitrenes are photoreactive in the inert matrix isomerizing to cyclopropene derivatives.

• Journal of Korea Foundry Society
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• v.14 no.3
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• pp.258-266
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• 1994

AC4A $Al/Al_2O_3+SiC_p$ hybrid composites were fabricated by the squeeze infiltration technique. Effect of applied pressure, volume fraction of reinforcement($Al_2O_3$ and SiC) and SiC particle size($4.5{\mu}m$, $6.5{\mu}m$ and $9.3{\mu}m$) on the solidification microstructure of the hybrid composites were examined. Mechanical properties were estimated preliminarly by fractographic observation, hardness measurement and wear test. Results show that the microstructure of the hybrid composites were quite satisfactory, namely revealing relatively uniform distribution of reinforcements and refined matrix. Some aggregation of SiC particle caused by particle pushing was observed especially in the hybrid composites containg in fine particle($4.5{\mu}m$). Refined matrix was attributed to applied pressure and increased nucleation sites with addition of reinforcements. Fractured facet also revealed finer for the hybrid composites possibly due to refined matrix. Hardness and wear resistance increased with volume fraction of reinforcements. For hybrid composites with $9.3{\mu}m$ SiC, hardness was somewhat lower and wear resistance higher than other composites.

• Communications of the Korean Mathematical Society
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• v.32 no.2
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• pp.261-266
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• 2017

H. R. Ebrahimi Vishki et al. conjectured in [1], that if every Jordan higher derivation on a trivial generalized matrix algebra $\mathcal{G}=(A,M,N,B)$ is a higher derivation, then either M = 0 or N = 0. In this note, we will give a class of counter examples.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.141-144
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• 2004

A QVGA active-matrix backplane is produced on a 25${\mu}m$ thin plastic substrate. A 4-mask photolithographic process is used. The insulator layer and the semiconductor layer are organic material processed from solution. This backplane is combined with the electrophoretic display effect supplied by SiPix and E ink, resulting in an electronic paper display with a thickness of only 100${\mu}m$. This is world's thinnest active-matrix display ever made.

• Journal of applied mathematics & informatics
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• v.5 no.1
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• pp.13-22
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• 1998

Fractals which represent many of the sets in various scien-tific fields as well as in nature is geometrically too complicate. Then we usually use Hausdorff dimension to estimate their geometrical proper-ties. But to explain the fractals from the hausdorff dimension induced by the Euclidan metric are not too sufficient. For example in digi-tal communication while encoding or decoding the fractal images we must consider not only their geometric sizes but also many other fac-tors such as colours densities and energies etc. So in this paper we define the dimension matrix of the sets by redefining the new metric.

• Journal of applied mathematics & informatics
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• v.24 no.1_2
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• pp.273-282
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• 2007

In this paper, we study the convergence of both the multisplitting method and the relaxed multisplitting method associated with SOR or SSOR multisplittings for solving a linear system whose coefficient matrix is an M-matrix.