• 통합자연과학논문집
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• 제11권1호
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• pp.51-56
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• 2018

For topological vector spaces X and Y, let $F_0(X,Y)=\{f{\in}Y^X:f(0)=0\}$. Then it is an extremely large family and the family of linear operators is a very small subfamily of $F_0(X,Y)$. In this paper, we establish the characterizations of $F_0(X,Y)$-matrix families (${l^{\infty}(X)$, ${l^{\infty}(Y)$), ($c_0(X)$, $l^{\infty}(Y)$) and ($c_0(X)$, $l^{\infty}(Y)$).

• Restorative Dentistry and Endodontics
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• 제36권1호
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• pp.26-36
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• 2011

연구목적: 본 연구는 in vitro 상에서 치수, 치은, 치주인대 세포를 neuropeptide (substance P, Calcitonin gene related peptides (CGRP))및 inflammatory cytokine (TNF-$\alpha$)으로 자극 시 matrix metalloproteinase (MMPs)의 생성 및 발현을 관찰한 것으로 치아와 치아 주변 조직에 염증이 존재할 경우 neuropeptide 및 inflammatory cytokine과 치아 경조직 혹은 치조골의 remodeling에 중요한 역할을 하는 matrix metalloproteinase (MMPs)와의 관계를 규명하고자 하였다. 연구 재료 및 방법: 시편으로는 우식이 없는 건전한 제3대구치(n = 10)를 사용하였으며, 발거 후 즉시 Phosphate buffered saline (PBS)에 보관하고 치아에서 치은과 치주인대 조직을 채취하였다. 치아를 종축으로 절단하고 치수 조직을 채취하여 조각으로 분리한 후 시편을 PBS에서 세 번 세척하였다. Plate에 치수, 치은, 치주인대 시편 조각을 위치시켜 Dulbecco's Modified Eagle Medium (DMEM)을 첨가하여 세포를 배양하였다. 치수, 치은, 치주인대 세포를 culture dish에서 confluence에 도달할 때 까지 배양하여 Fetal Bovine Serum (FBS)가 포함되지 않은 배지로 교환하여, $37^{\circ}C$에서 24시간 동안 배양한 후 Phosphate buffered saline (PBS)로 1회 세척하고 Substance P ($10^{-8}\;M$, $10^{-5}\;M$)가 포함된 배양액과 Mock (배양액만 포함됨)으로 4시간, 24시간동안 자극하였다. CGRP ($10^{-6}\;M$)을 함유한 배양액 및 TNF-$\alpha$(2 ng/mL)를 포함한 배양액으로 각각 24시간동안 세포를 자극하였다. 각각 다른 농도의 TNF-$\alpha$(2 ng/mL, 10 ng/mL, 100 ng/mL)를 포함한 배양액으로 24시간 동안 세포를 자극 한 후 RNase protection assay 및 Enzyme linked immunosorbent assay를 시행하였다. 결과: SP와 CGRP는 치수, 치은, 치주인대 세포의 MMPs발현에 관여 하지 않았다. TNF-$\alpha$로 24시간 자극 시 치수, 치은, 치주인대 세포에서 MMP-1,-12, -13의 발현을 증가시켰다. 반면, TNF-$\alpha$는 치수, 치은, 치주인대 세포들에서 TIMP-3의 발현을 감소시켰다. 서로 다른 농도의 TNF-$\alpha$(2 ng/mL, 10 ng/mL, 100 ng/mL)로 24시간 자극 시 MMP-1과 MMP-13의 발현이 증가하였다. 결론: 치아와 치아 주변 조직에 염증이 존재 시 TNF-$\alpha$가 증가함에 따라 치수, 치은, 치주인대로부터의 치아의 경조직 혹은 치조골의 remodeling에 관여하는 matrix metalloproteinase (MMPs)가 중요한 역할을 하는 것으로 사료된다.

• 분석과학
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• 제5권4호
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• pp.349-358
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• 1992

본 연구에서는 흑연로 원자흡수분광법을 이용하여 혈액을 1% Triton X-100을 5배 희석시킨 다음 납 함량을 직접 측정하였다. 혈액내 방해 성분을 제거하기 위하여 매트릭스 변형제를 사용하여 최적의 분석 조건을 조사하였다. 매트릭스 변형제로서 1% $(NH_4)_2HPO_4$와 0.1% $PdCl_2$를 같이 사용하고 700도에서 회화시켰을 때에, 일본 비교 분석 프로그램에 의해 제공된 혈중 납 함량에 대한 정도관리용 표준시료(우혈)의 공인값과 비교적 잘 일치하였다. 이 실험에서 얻은 표준편차는 $31{\mu}gPb/l$에서 $624{\mu}gPb/l$ 범위에서는 1% $(NH_4)_2HPO_4$ 및 1% $(NH_4)_2HPO_4$와 0.1% $PdCl_2$를 매트릭스 변형제로서 사용했을 경우 각각 2.2~6.3%, 3.1~9.1%였다.

• 공업화학
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• 제7권4호
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• pp.735-742
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• 1996

장시간에 걸쳐 약물의 흡수가 일어날 수 있는 고분자 matrix을 개발하고자, 글리세린과 증류수를 혼합 교반 시킨 후, 분자량이 서로 다른 세 종류의 dextran을 각각 첨가하여 용해시켰다. 이 용액에 silver sulfadiazine을 분산시켜 matrix를 제조하였다. 이렇게 제조된 고분자 matrix로부터 약물 방출 양상을 규명하기 위해 인산염 완충용액 중에서 약물의 함유량 변화, dextran의 분자량 변화 및 글리세린의 농도 변화에 영향을 미치는 인자들에 관하여 연구 검토한 바 다음과 같은 결론을 얻었다. 고분자 matrix내의 silver sulfadiazine의 함유량이 증가할수록 약물 방출 지속 시간은 11.2일, 14.0일 및 15.8일로 지연되었다. Dextran의 분자량 변화에 대해서는 약 14.0일로 거의 같은 약물 방출 pattern을 보임으로써 겉보기 방출속도상수 (K)값과의 관계와 일치하는 결과를 얻었다. 그러나 글리세린의 함유량이 증가함에 따라 약물 방출 지속 시간은 각각 18.0일, 17.0일, 14.0일, 13.0일 및 10.0일로 감소하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.305-308
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• 2006

Advanced mobile communication devices require a bright, high information content display in a small, light-weight, low power consumption package. For portable applications flexible (or conformable) and rugged displays will be the future. In this paper we outline our progress towards developing such a low power consumption active-matrix flexible OLED $(FOLED^{TM})$ display. We demonstrate full color 100 ppi QVGA active matrix OLED displays on flexible stainless steel substrates. Our work in this area is focused on integrating three critical enabling technologies. The first technology component is based on UDC's high efficiency long-lived phosphorescent OLED $(PHOLED^{TM})$ device technology, which has now been commercially demonstrated as meeting the low power consumption performance requirements for mobile display applications. Secondly, is the development of flexible active-matrix backplanes, and for this our team are employing PARC's Excimer Laser Annealed (ELA) poly-Si TFTs formed on metal foil substrates as this approach represents an attractive alternative to fabricating poly-Si TFTs on plastic for the realization of first generation flexible active matrix OLED displays. Unlike most plastics, metal foil substrates can withstand a large thermal load and do not require a moisture and oxygen permeation barrier. Thirdly, the key to reliable operation is to ensure that the organic materials are fully encapsulated in a package designed for repetitive flexing, and in this device we employ a multilayer thin film Barix encapsulation technology in collaboration with Vitex systems. Drive electronics and mechanical packaging are provided by L3 Displays.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2004년도 The 3rd Annual Conference for The Korean Society for Bioinformatics Association of Asian Societies for Bioinformatics 2004 Symposium
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• pp.265-271
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• 2004

The interaction network of protein -protein plays an important role to understand the various biological functions of cells. Currently, the high -throughput experimental techniques (two -dimensional gel electrophoresis, mass spectroscopy, yeast two -hybrid assay) provide us with the vast amount of data for protein-protein interaction at the proteome scale. In order to recognize the role of each protein in their network, the efficient bioinformatical and computational analysis methods are required. We propose a systematic and mathematical method which can analyze the protein -protein interaction network rigorously and enable us to capture the biological and physical essence of a topological character and stability of protein -protein network, and sensitivity of each protein along the biological pathway of their network. We set up a Laplacian matrix of spectral graph theory based on the protein-protein network of yeast proteome, and perform an eigenvalue analysis and apply a perturbation method on a Laplacian matrix, which result in recognizing the center of protein cluster, the identity of hub proteins around it and their relative sensitivities. Identifying the topology of protein -protein network via a Laplacian matrix, we can recognize the important relation between the biological pathway of yeast proteome and the formalism of master equation. The results of our systematic and mathematical analysis agree well with the experimental findings of yeast proteome. The biological function and meaning of each protein cluster can be explained easily. Our rigorous analysis method is robust for understanding various kinds of networks whether they are biological, social, economical...etc

• 열처리공학회지
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• 제22권6호
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• pp.345-353
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• 2009

The precipitates of $L2_1$-type $Ni_2AlHf$ phase in B2-ordered NiAl system has been observed by using transmission electron microscope (TEM). The hardness of as-quenched NiAl-Hf alloys is high due to the larger strengthening. However, age hardening of this alloy is not main effect to increase hardness compared to the large microstructural variations during aging. At the beginning of aging, the $L2_1$-type $Ni_2AlHf$ precipitates keep a lattice coherency with the NiAl matrix. The orientation relationship between the $Ni_2 AlHf$ precipitate and the NiAl matrix is <100>$_{Ni2AlHf}$//<100>$_{NiAl}$, {001}$_{Ni2AlHf}$//{001}$_{NiAl}$. By aging treatment for long time $Ni_2AlHf$ precipitates lost their coherency and change their morphology to the spherical ones surrounded by misfit dislocations. The orientation relationship between the NiAl matrix and the $Ni_2AlHf$ precipitates, however, has been kept even after longer aging time. The lattice misfit between the $Ni_2AlHf$ precipitate and the NiAl matrix has been calculated by the selected electron diffraction patterns, and the spacings of misfit dislocations is about 4.5% at 1173 K.

• 환경위생공학
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• 제16권3호
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• pp.80-86
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• 2001

This research was carried out to investigate the effect of microscopic silica matrix coagulation on heavy metals and anion removal in mining wastewater. pH and alkalinity played an important role to coagulate heavy metals such as Al, and Fe and an anion such as ${SO_4}^{2-}$ with silica matrix as well as NaOH. However, the efficiency to form coagulates was much greater in silica matrix-treated wastewater than NaOH-treated one. Fe in wastewater formed coagulation with both silica matrix and NaOH treatments resulting in lowering Fe content in wastewater at above pH 9. For Al removal in wastewater, silica matrix-treated wastewater at above pH 12.3 formed stable coagulate with Al, while NaOH-treated one did not. Alkalinities of 89 and 220 mg/L were required to stabilize silica matrix treated coagulate with Fe and Al, respectively. Reaction time of ten minute was required to provide enough reaction for coagulation between heavy metals and silica matrix. Heavy metals and anion leachates were much lower in coagulate with silica matrix than that with NaOH, which indicates that silica matrix could be used to remove heavy metals efficiently.

• East Asian mathematical journal
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• 제27권1호
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• pp.83-89
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• 2011

We denote by $\mathcal{Q}(A)$ the set of all matrices with the same sign pattern as A. A matrix A has signed -space provided there exists a set S of sign patterns such that the set of sign patterns of vectors in the -space of e $\tilde{A}$ is S, for each e $\tilde{A}{\in}\mathcal{Q}(A)$. In this paper, we show that the number of sign patterns of elements in the row space of $\mathcal{S}^*$-matrix is $3^{m+1}-2^{m+2}+2$. Also the number of sign patterns of vectors in the -space of a totally L-matrix is obtained.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.635-638
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• 2003

In the paper, a three-phase-in three-phase-out Matrix Converter(MC) for the PMSM Is simulated by the PSIM simulator. A lighter L-C filters are installed at the input side of the Converter to remove the current harmonics around the switching frequency. In modelling the Matrix Converter, the PSIM is the powerful tool that the basic researches can be quickly performed within the given periods, because the simulation calculation by PSIM is very fast, compared to other simulators such as Matlab, Saber, and Pspice.