• Biomolecules & Therapeutics
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• 제24권6호
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• pp.610-615
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• 2016

Quercetin, a flavonol, has been reported to exhibit a wide range of biological properties including anti-oxidant and anti-inflammatory activities. However, pharmacological properties of quercetin-3-O-${\beta}$-D-glucuronide (QG), a glycoside derivative of quercetin, have not been extensively examined. The objective of this study is to elucidate the anti-inflammatory property and underlying mechanism of QG in lipopolysaccharide (LPS)-challenged RAW264.7 macrophage cells in comparison with quercetin. QG significantly suppressed LPS-induced extracellular secretion of pro-inflammatory mediators such as nitric oxide (NO) and $PGE_2$, and pro-inflammatory protein expressions of iNOS and COX-2. To elucidate the underlying mechanism of the anti-inflammatory property of QG, involvement of MAPK signaling pathways was examined. QG significantly attenuated LPS-induced activation of JNK and ERK in concentration-dependent manners with a negligible effect on p38. In conclusion, the present study demonstrates QG exerts anti-inflammatory activity through the suppression of JNK and ERK signaling pathways in LPS-challenged RAW264.7 macrophage cells.

• 전자공학회논문지CI
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• 제42권3호
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• pp.39-52
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• 2005

본 논문에서는 실내환경의 3차원 복원을 위해 다시점 카메라부터 획득된 부분적인 3차원 점군에 대한 정합 기법을 제안한다. 일반적으로, 기존의 정합 방법들은 많은 계산량을 요하며, 정합하는데 많은 시간이 소요된다 또한, 상대적으로 정밀도가 낮은 3차원 점군에 대해서는 정합이 어렵다. 이러한 문제점을 해결하기 위해 투영 기반 정합 방법을 제안한다. 첫 번째, 시간적 특성을 기반으로 변화량이 큰 3차원 점들을 제거하고, 공간적 특성을 이용하여 현재 화소의 주변 3차원 점을 참조하여 빈 영역을 채움으로써 깊이 영상 정제 과정을 수행한다. 두 번째, 연속된 두 장면에서의 3차원 점군을 동일한 영상 평면으로 투영하고, 두 단계 정수 매핑을 적용한 후 수정된 KLT (Kanade-Lucas-Tomasi) 특징 추적기를 사용해 대응점을 찾는다. 그리고 적응적 탐색 영역에 기반하여 거리 오차를 최소화함으로써 정밀한 정합을 수행한다. 마지막으로, 대응되는 점들에 대한 색을 참조하여 최종적인 색을 계산하고, 위의 과정을 연속된 장면에 적용함으로써 실내환경을 복원한다. 제안된 방법은 대응점을 2차원 영상 평면에서 찾음으로써 계산의 복잡도를 줄이며, 3차원 데이터의 정밀도가 낮은 경우에도 정합이 효과적이다. 또한, 다시점 카메라를 이용함으로써 몇 장면에 대한 색과 깊이 영상만으로도 실내환경의 3차원 복원이 가능하다.

• 동력기계공학회지
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• 제8권3호
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• pp.18-22
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• 2004

Boiler is one of the most important utilities providing steam to turbine in order to supply mechanical energy in thermal power plant. It is composed of thousands of tubes for high efficient heat transfer. The material for boiler tubes is used in such high temperature and pressure condition as $540^{\circ}C$, 22MPa. The boiler tube material is required to resist creep damage, fatigue cracking, and corrosion damages. 2.25%Cr-1Mo steel is used for conventional boiler tubes, and austenitenite stainless steel is used for higher temperature boiler tubes. But the temperature and pressure of steam in power plant became higher for high plant efficiency. So, the property of boiler tube material must be upgaded to fit the plant property. Several boiler tube material was developed to fit such conditions. X20CrMoV12.1 steel is also developed in 1980's and used for superheater and reheater tubes in supercritical boilers. The material has martensite microstructures which is difficult to evaluate the degradation. In this thesis, degrade the X20CrMoV12.1 steel at high temperatures in electric furnace, and evaluate hardness with Vickers hardness tester and strengths with Indentation tester.

• Journal of Welding and Joining
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• 제14권5호
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• pp.49-58
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• 1996

In Korea Gas Corporation, as one of the pipeline repairing methods, damaged pipelines are sometimes treated with a temporally employment of split sleeve. On conducting the repair process, circumferential fillet and longitudinal groove welding usually must be included. For the case of groove welding, a considerable amount of R&D have been carried out related to property changes, while few study on the property change in fillet welding has been conducted. In this paper, so as to confirm the specification of fillet welding in terms of safety and reliability, properties changed by fillet welding were investigated for two welding processes. Qualifying tests such as reviewing macrostructure and nick-break tests were performed according to API 1104 and ASME section IX. In addition, tensile properties and hardness were evaluated according to KS B0841 and BS 4515. The fillet weld prepared by the qualified procedure showed melting depth of 0.8∼1.3mm and heat affected zone of 2.8∼3.4mm length. No crack and lack of penetration were observed. And the results of hardness and nick-break tests satisfied code requirements. The area crossed by fillet and groove welding line was found to have minimal tensile strength.

• 대한수학회보
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• 제33권3호
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• pp.359-366
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• 1996

A linear map T from a Banach algebra A into a Banach algebra B is almost multiplicative if $\left\$\mid$ T(fg) - T(f)T(g) \right\$\mid$ \leq \in\left\$\mid$ f \right\$\mid$\left\$\mid$ g \right\$\mid$(f,g \in A)$ for some small positive $\in$. B.E.Johnson [4,5] studied whether this implies that T is near a multiplicative map in the norm of operators from A into B. K. Jarosz [2,3] raised the conjecture : If T is an almost multiplicative functional on uniform algebra A, there is a linear and multiplicative functional F on A such that $\left\$\mid$ T - F \right\$\mid$ \leq \in', where \in' \to 0$ as $\in \to 0$. B. E. Johnson [4] gave an example of non-uniform commutative Banach algebra which does not have the property described in the above conjecture. He proved also that C(K) algebras and the disc algebra A(D) have this property [5]. We extend this property to a derivation on a Banach algebra.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.65-68
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• 2004

A lot of R&D efforts are being concentrated on the development of high performance HTS coated conductors(CC). Unlike the HTS Bi-2223 tape, a variety of processes have been tried to fabricate CC tapes. PLD and MOD are believed to be very effective methods, and high critical currents of long length CC tape have been reported. In this study, we prepared two kinds of YBCO CCs to evaluate electromagnetic property. One is YBCO tape deposited on IBAD template by PLD and the other is AMSC's MOD CC tape Critical current (Ic) in magnetic fields, its angular dependency, and n-value were measured and analyzed. Magnetic field property of Ic was appeared to be different due the fabrication process. MOD tape showed higher in-field property, n-value of both PLD and MOD tapes exponentially decreased with magnetic field. MOD tape showed higher n-value in whole magnetic fields.

• 한국염색가공학회지
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• 제21권6호
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• pp.12-21
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• 2009

The dyeing property of direct-spinning type and seaisland type 0.2D micro polyester nonwoven fabrics was characterized by three disperse dyes (Dorosperse Red KFFB, Blue KGBR, Yellow KRL) at $120^{\circ}C$ and $130^{\circ}C$. Before and after reduction cleaning, dyeing fastness was evaluated and the thermomigaration after heat setting at $180^{\circ}C$ for 60 min were also evaluated. Direct-spinning type fabric showed better dyeing property, wash fastness, and light fastness, but worse rub fastness than seaisland type fabric. The dyeing property and fastness of direct-spinning type fabric increased at higher dyeing temperature, whereas seaisland type fabric exhibited lower dyeing fastness and the increase of thermomigration at higher dyeing temperature. Non-fixed dye in fiber surface was removed by reduction cleaning process, then dyeing fastness was improved and thermomigration decreased. The higher dye uptake of direct-spinning type non-woven fabric caused the increase of dye molecule migration from fiber internal to fiber surface, so this fabric showed larger thermomigration than seaisland type non-woven fabric.

• East Asian mathematical journal
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• 제25권2호
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• pp.179-196
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• 2009

Let E be a uniformly convex Banach space and K a nonempty closed convex subset which is also a nonexpansive retract of E. For i = 1, 2, 3, let $T_i:K{\rightarrow}E$ be an asymptotically nonexpansive mappings with sequence ${\{k_n^{(i)}\}\subset[1,{\infty})$ such that $\sum_{n-1}^{\infty}(k_n^{(i)}-1)$ < ${\infty},\;k_{n}^{(i)}{\rightarrow}1$, as $n{\rightarrow}\infty$ and F(T)=$\bigcap_{i=3}^3F(T_i){\neq}{\phi}$ (the set of all common xed points of $T_i$, i = 1, 2, 3). Let {$a_n$},{$b_n$} and {$c_n$} are three real sequences in [0, 1] such that $\in{\leq}\;a_n,\;b_n,\;c_n\;{\leq}\;1-\in$ for $n{\in}N$ and some ${\in}{\geq}0$. Starting with arbitrary $x_1{\in}K$, define sequence {$x_n$} by setting {$$x_{n+1}=P((1-a_n)x_n+a_nT_1(PT_1)^{n-1}y_n)$$ $$y_n=P((1-b_n)x_n+a_nT_2(PT_2)^{n-1}z_n)$$ $$z_n=P((1-c_n)x_n+c_nT_3(PT_3)^{n-1}x_n)$$. Assume that one of the following conditions holds: (1) E satises the Opial property, (2) E has Frechet dierentiable norm, (3) $E^*$ has Kedec -Klee property, where $E^*$ is dual of E. Then sequence {$x_n$} converges weakly to some p${\in}$F(T).

• 한국지반신소재학회논문집
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• 제4권3호
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• pp.11-19
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• 2005

2가지 형태의 지오그리드의 장기안정성을 평가하였다. 멤브레인 연신형 지오그리드는 지수함수 형 인장특성을 나타내었으며 섬유형 지오그리드는 파단점에 근접할수록 빠른 인장특성의 증가를 나타내었다. 단기 가속 크리프 시험은 섬유형 지오그리드에는 실시되었지만 멤브레인 연신형 지오그리드의 경우 열적특성 때문에 실온에서만 실시 하였다. 멤브레인 연신형 지오그리드의 크리프 변형률은 인장시험에 의한 극한 인장변형률보다 크게 나타났다. 섬유형 지오그리드의 크리프 변형에 의한 감소인자는 멤브레인 연신형 지오그리드보다 작게 나타났다. 이 결과로부터 섬유형 지오그리드가 멤브레인 연신형 지오그리드보다 크리프 변형에 안정성이 있음을 알 수 있었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.1737-1741
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• 1991

The authors proposed a new two-dimensional(2D) positioning system by use of M-array and correlation technique which is suitable for noisy environment in '88KACC and its revised versions in '89KACC and '90KACC. This system uses the property of M-array that the autocorrelation function of the M-array has a sharp peak at its origin. In this paper, a new mark pattern is developed, instead of M-array, with which the two-dimensional positioning system becomes robust to rotation error of TV camera. The property of the rotation-free pattern is checked under various conditions, and it is shown that, by use of this rotation-free pattern, the positioning system can be used not only in a noisy environment but also in a roughly aligned set up of the TV camera.