• 한국수자원학회논문집
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• 제32권4호
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• pp.437-445
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• 1999

비모수능형회귀분석법을 이용하여 수문응답을 추정하는 방안에 대하여 연구하였다. 응답을 추정하기 위하여 평균제곱예측오차에 대한 추정량인 CL 통계량을 최소화하는 방법을 적용하였으며 가중행렬은 전통적으로 이용도는 단위행렬과 특수한 형태인 행렬인 Laplacian 행렬을 각각 이용하여 비교하였다. 또한 추정응답의 오차분산을 추정하는 방안에 대한 검토도 실행하였다. 합성자료와 실제자료에 대한 분석 결과 가중행렬과 Laplacian 행렬을 오차분산은 편기 수정된 추정치를 이용하는 것이 좋은 결과를 보여 주었다. 본 연구에서 제시된 절차 및 방법은 수문응답 분리에 있어서 안정적이고 효율적으로 적용될 수 있을 것으로 판단된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 하계종합학술대회 논문집
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• pp.189-194
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• 1989

The sparse vector method is more efficient than conventional sparse matrix method when solving sparse system. This paper considers the structural relation between factorized L and inverse of L and presents a new ordering algorithm for sparse vector method. The method is useful in enhancing the sparsity of the inverse of L while preserving the aparsity of matrix. The performance of algorithm is compared with conventional algorithms by means of several power system.

• 충청수학회지
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• 제23권2호
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• pp.363-368
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• 2010

In this paper we construct a subalgebra $L_8$ of $M_8({\mathbb{R}})$ which is a generalization of the algebra of quaternions. Moreover we prove that the algebra $L_8$ is the real Clifford algebra $Cl_3$, and so $L_8$ is a matrix representation of Clifford algebra $Cl_3$.

• Journal of Pharmaceutical Investigation
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• 제20권1호
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• pp.13-18
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• 1990

Hydrocortisone (HC) sustained-release suppositories were prepared by using a solid matrix of methacrylic acid-methacrylic acid methyl ester copolymer $(Eudragit\;L_{100}^{R}:\;EL)$ as a poorly water soluble carrier and polyethylene glycole 1540 (PEG) as an water soluble carrier. HC release rate was controlled by complexation with ${\beta}-cyclodextrin$ $({\beta}-CyD)$ which was confirmed by X-ray diffractometry, IR-spectroscopy and differential scanning calorimetry. Release rate of HC from the EL-PEG matrix suppositories decreased with increase of EL contents. The release rale from $HC-{\beta}-CyD$ complex decreased in the following order: $HC-{\beta}-CyD/PEG$ > HC/PEG > $HC-{\beta}-CyD/EL_{10%}-PEG$ > $HC/EL_{10%}-PEG$ > $HC-{\beta}-CyD/EL_{15%}-PEG$ > $HC/EL_{15%}-PEG$ > $HC-{\beta}-CyD/EL_{20%}-PEG$ > $HC/EL_{20%}-PEG$. The crystallinity of HC in polymer matrix was identified using X-ray diffractometer and the surface of matrix suppositories after release test was examined by scanning electron microscopy. The sustained release of HC from these matrix suppositories was attributed to the network structure of EL.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2004년도 Proceedings of the 4th Korea-China Joint Workshop on Nuclear Waste Management
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• pp.182-190
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• 2004

An unique extraction chromatographic column (TOA: Tri-n-octylamine on Teflon powder) with a two-stage sample loading was prepared to separate Np and Pu from the environmental matrix. Np and Pu were efficiently retained in 4 M $HNO_3$ medium on the column and easily eluted with 0.02 M oxalic acid in 0.16 M HNO$_3$at $95^{\circ}C$. The separated solutions were free from most of the matrix elements and were aspirated into the ICP-MS directly. The decontamination factor for 238U is more than 104. The instrumental detection limit for 237Np was 0.46 pg mL-l ($1.2{\times}10_{-5}$Bq mL-l), and for 239Pu was 0.48 pg mL-l ($1.1{\times}10_{-3}$ Bq mL-l). The feasibility for the determination of both elements was proved by analysing IAEA-135 reference samples, the measured values agreed with the recommended reference value.

• 대한화장품학회지
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• 제40권4호
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• pp.365-371
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• 2014

새로운 주름개선제 성분을 찾기 위해서 본 연구에서는 사람 피부 섬유아세포의 세포독성, 콜라겐 생합성, matrix metalloproteinase-I (MMP-1) 및 elastase 저해활성에 대한 Lactobacillus plantarum으로 발효된 오미자 발효액의 주름개선 효과를 평가하였다. 먼저, 오미자 추출물은 L. rhamnosus으로 $37^{\circ}C$에서 1일 동안 발효하였다. 발효물의 세포독성은 cytopathic effect reduction 방법에 의해 평가하였다. 콜라겐 생합성에 대한 발효물의 영향은 procollagen type-IC peptide EIA kit에 의해 평가하였으며, matrix metalloproteinase-I(MMP-1)에 대한 발효물의 영향은 Matrix Metalloproteinase-1 Biotrack activity Assay Kit에 의해 평가하였다. Elastase inhibition assay는 기질로써 N-Suc-$(Ala)_3$-nitroanilide을 사용하여 기질 반응에 의해 평가하였다. 결과로써 오미자 발효물은 사람 피부 섬유아 세포에 대해 $100{\mu}g/mL$의 농도에서 세포독성을 나타내지 않았다. 또한 오미자 발효물은 콜라겐 생합성을 촉진시켰으며, MMP-1의 저해 효과를 나타내었다(p < 0.05). Elastase inhibition assay에서 오미자 발효물의 $IC_{50}$은 $36.4{\mu}g/mL$이었다. 그러므로 본 연구에서 오미자 발효물은 주름개선 효과를 보유하고 있으며, 이것은 피부의 주름개선을 위해 사용가능하리라 사료된다.

• 대한수학회논문집
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• 제35권2호
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• pp.487-497
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• 2020

In this paper, we establish a complex matrix representation of the Clifford algebra Cℓ_p,q. The size of our representation is significantly smaller than the size of the elements in L_p,q(ℝ). Additionally, we give detailed information about the spectrum of the constructed matrix representation.

• Journal of Pharmaceutical Investigation
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• 제15권3호
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• pp.93-99
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• 1985

For the effective immobilization of urease on chitosan matrix with glutaraldehyde, optimal activation methods were studied, and its enzymatic properties was investigated. In the stability of enzyme. the retained activity of the native urease was 55% after it was soaked af pH 7 for 10 hrs., while the retained activity of immobilized one was about 62% after soaked at pH 6.5-8.5 for the same time. After heat treatment at $60^{\circ}C$ for 10 hrs., the native urease lost the most of its activity, while immobilized urease retained 54% of its activity by the same treatment. The retained activity of immobilized urease did not decrease nearly when it was stored at room temperature for 25 days. From Linweaver-Burk plots, the $V_{max}$ value of native urease was $66{\mu}M/l$ and that of immobilized urease was $41{\mu}M/l$, while Km value 40mM/l for both enzymes was unaltered.

• Journal of applied mathematics & informatics
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• 제28권5_6호
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• pp.1117-1130
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• 2010

The main goal for this paper is consider the necessary conditions and sufficient conditions of wavelet frames in higher dimensions with an arbitrary expanding matrix dilation. At first, we give a necessary condition of wavelet frame in $L^2(R^n)$, which generalizes the univariate results of Shi from one dimension with an arbitrary real number a(a > 1) dilation to higher dimension with an arbitrary expansive matrix dilation. Secondly, we deduce a necessary condition for wavelet frames in $L^2(R^n)$ when the function $\psi$ satisfies some property of the decay. For the case n = 1, we obtain a corollary which has weaker condition comparing with existing result.

• 경영과학
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• 제11권3호
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• pp.1-11
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• 1994

Recent advances in linear programming solution methodology have focused on interior point methods. This powerful new class of methods achieves significant reductions in computer time for large linear programs and solves problems significantly larger than previously possible. These methods can be examined from points of Fiacco and McCormick's barrier method, Lagrangian duality, Newton's method, and others. This study presents a primal-dual log barrier algorithm of interior point methods for linear programming. The primal-dual log barrier method is currently the most efficient and successful variant of interior point methods. This paper also addresses a Cholesky factorization method of symmetric positive definite matrices arising in interior point methods. A special structure of the matrices, called supernode, is exploited to use computational techniques such as direct addressing and loop-unrolling. Two dense matrix handling techniques are also presented to handle dense columns of the original matrix A. The two techniques may minimize storage requirement for factor matrix L and a smaller number of arithmetic operations in the matrix L computation.