• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2010.11a
• /
• pp.252-253
• /
• 2010

H.264/AVC는 P 슬라이스에 2개의 인트라 모드, 4개의 인터 모드 그리고 SKIP모드, 총 7개의 모드를 허용한다. 다양한 블록 모드들을 효율적으로 이용하기 위하여 RDO를 통하여 최적의 모드를 결정한다. 그러나 SKIP 모드의 RD 점과 다른 모드들의 RD점 사이의 간격이 넓은 문제점이 있다. 이러한 문제점은 부호화 성능에 영향을 미친다. 본 논문에서는 SKIP 모드와 4개의 인터 모드 사이의 RD 성능의 중간 성격을 지니는 새로운 인터 모드를 제안한다. 제안하는 방법은 inter16x16의 움직임 정보와 inter16x16의 움직임 정보를 이용하여 찾은 예측 블록에 대한 잔차 블록의 평균 에너지만을 보내준다. 실험 결과 제안하는 방법은 H.264/AVC의 참조 소프트웨어인 JM 17.0에 비하여 WQVGA 영상에서 평균 0.71%의 비트 감소를 나타내었다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2010.07a
• /
• pp.343-345
• /
• 2010

H.264/AVC는 율-왜곡 계산에 기반한 화면 내 예측과 화면 간 예측을 통하여 높은 압축효율을 나타낸다. 그러나 모든 예측 모드의 율-왜곡 값을 계산하여 하나의 최적의 모드를 구하는 기존의 방법은 높은 계산량을 가지며 부호화에 걸리는 시간을 현저히 증가시킨다. 이러한 높은 계산량을 갖는 모든 예측모드의 율-왜곡 계산을 보완하기 위하여, 본 논문에서는 매크로블록의 움직임 특성 을 고려한 고속 부호화 모드 결정 방법을 제안한다. 각각의 매크로블록을 부호화하기 위해 미리 계산되는 SKIP모드에 대한 율-왜곡 값을 바탕으로 두 가지 문턱 값을 사용하여 움직임의 특성을 판단한다. 움직임의 특성에 따라 매크로블록은 3가지 분류로 나뉘게 되며, 각 분류에 따라 경쟁 모드를 적응적으로 선별하여 최적의 모드를 선택한다. 이러한 움직임 특성을 고려한 선택적 부호화 모드 결정을 통하여 부호화 효율의 큰 손실 없이 계산량을 감소시킴으로서 H.264/AVC의 고속 부호화가 가능한 x.264 대비 MMX를 사용하였을 때 16%, MMX를 사용하지 않았을 때 22%의 속도향상을 가져왔다.

• Korean Journal of Metals and Materials
• /
• v.49 no.3
• /
• pp.264-269
• /
• 2011

Hydrogen and hydrogen energy have been recognized as clean energy sources and high energy carrier. Mg and Mg alloys are attractive hydrogen storage materials because of their lightweight and low cost materials with high hydrogen capacity (about 7.6 wt.%). However, the commercial applications of the Mg hydrides are currently hinder by its high absorption/desorption temperature, and very slow reaction kinetics. However, Ti and Ti based hydrogen storage alloys have been thought to be the third generation of alloys with a high hydrogen capacity, which makes it difficult to handle because of high reactivity. One of the most methods to develope kinetics was addition of transition metal. Therefore, Mg-Ti-Cr-Nb alloy was fabricated to add TiCrNb by hydrogen induced mechanical alloying. TiCrNb systems have included transition metals, low operating temperatures and hydrogen storage materials. As-received specimens were characterized using X-ray Diffraction analysis (XRD), Scanning Electron Microscopy (SEM) and Thermo Gravimetric analysis/Differential Scanning Calorimetry (TG/DSC). $Mg-TiCr_{10}Nb$ systems were evaluated for hydrogen kinetics by Sievert's type Pressure-Composition-Isotherm (PCI) equipment. The operating temperature range was 473, 523, 573 and 623 K.

• Bulletin of the Korean Chemical Society
• /
• v.16 no.3
• /
• pp.261-264
• /
• 1995

A series of samples of the Nd1-x(Ba0.40Mg0.60)1+xFeO4-y (x=0.00, 0.10, 0.20, and 0.30) system has been synthesized at 1450 ℃ under an atmospheric air pressure. The x-ray powder diffraction analysis of the solid solutions assigns the structure of all the compositions to orthorhombic system. Mohr salt analysis shows that τ and y values increase with x value and nonstoichiometric chemical formulas of the system can be formulated from the x, τ, and y values. Oxygen vacancies are distributed along c-axis in the perovskite layer. The magnetic ordering temperature remains unchanged with x value. Electrical conductivity and activation energy depend only on the mixed valence state of Fe ion. Conduction mechanism can be suggested as the hopping of electron between eg orbitals of Fe3+ and Fe4+ ions through Fe3+-O-Fe4+ bonds. Magnetic susceptibility and electrical conductivity are discussed with the nonstoichiometric chemical formulas.

• The Journal of Korean Obstetrics and Gynecology
• /
• v.25 no.2
• /
• pp.12-22
• /
• 2012

Objectives: The aim of this study is to investigate immune enhancing effect of Houttuyniae Herba water extract(HW) on RAW 264.7 cell of mouse macrophages. Methods: Effects of HW on productions of nitric oxide(NO) and hydrogen peroxide($H_2O_2$) in RAW 264.7 mouse macrophages were measured. Effect of HW on production of cytokines such as interleukin(IL)-$1{\beta}$, IL-6, and tumor necrosis factor(TNF)-${\alpha}$ in RAW 264.7 cells was accessed by a multiplex bead array assay based on xMAP technology. All of results were represented P<0.05 compared to the normal. Results: 1. After 24 hr incubation, HW increased significantly NO production in RAW 264.7 cells at the concentrations of 25, 50, 100 and 200 ${\mu}g$/mL. 2. After 24 hr incubation, HW increased significantly hydrogen peroxide production in RAW 264.7 cells at the concentrations of 25, 50, 100 and 200 ${\mu}g$/mL. 3. After 24 hr incubation, HW increased significantly IL-$1{\beta}$ production in RAW 264.7 cells at the concentrations of 100 and 200 ${\mu}g$/mL. 4. After 24 hr incubation, HW increased significantly IL-6 production in RAW 264.7 cells at the concentrations of 100 and 200 ${\mu}g$/mL. 5. After 24 hr incubation, HW increased significantly TNF-${\alpha}$ production in RAW 264.7 cells at the concentrations of 50, 100, and 200 ${\mu}g$/mL. Conclusions: These results suggest that HW has immune enhancing activity related with its increasement of NO, hydrogen peroxide, IL-$1{\beta}$, IL-6, and TNF-${\alpha}$ in macrophages.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1994.04a
• /
• pp.264-264
• /
• 1994

본 연구는 보리 씨앗에 존재하는 리보솜 불활성화 단백질(RIP) 의 삼차원 구조를 X-선 결정학 방법을 이용하여 밝히고, 그 결과로 분자 차원에서 기능을 이해하는 것을 목적으로 하고있다. 리보솜불활성화 단백질은 N-glucosidase 반응을 통하여 단백질 합성을 저해하기 때문에 세포를 죽일 수 있다. 따라서 암세포만을 특정적으로 인식하는 다른 물질과 결합시키면 암세포만을 특정적으로 죽일 수 있는 면역독소로 이용될 수 있다. 또, 최근에는 항바이러스의 작용을 함이 밝혀져 많은 연구가 진행되고 있다. 단백질 삼차원 구조 규명을 위해서는 여러가지 단계가 있는데 지난 번 과제까지 성공적으로 리보솜 불활성화 단백질의 대량 분리와 X-선 결정학의 필수 요건 좋은 결정을 길렀고, 이번에는 구조 해석을 위해 꼭 해결해야하는 위상문제를 극복하기 위하여 여러가지 실험을 진행하였다. 우선, 비슷한 구조인 피마자씨에서 분리한 Ricin의 A-체인과 미국자리공 잎에서 분리한 Pokeweed antiviral protein의 삼차원 분자좌표를 이용하여 분자치환법으로 위상문제 해결을 시도하였다. Ricin 의 A-체인을 이용하였을 때 분자의 위치가 정확히 찾아지지 않았고, 다른 모델인 Pokeweed antiviral protein을 이용하여 X-PLOR 프로그램내의 PC refinement법으로 분자치환을 시도하였다. Euler각도로 (187.37, 22.5, 311.94) 의 회전해 (Rotation solution) 를 가지고 있었고, 이러한 해에 맞추어서 분자를 돌려둔 후, 이동해 (Transaltion solution) 을 구해서 그 위치 (Orientation) 로 분자를 이동하였다. 이 때 R값은 53.9 % (8.0 - 3.5$\AA$) 이였고, 부분좌표 (Fractional coorcdinate) 에서는 0.102, 0.000, 0.261 이고, 직교좌표 (Orthogonal coorclinate) 에서는 4.616, 0.000, 13.167 의 결과를 얻었다.

• Korean Journal of Materials Research
• /
• v.29 no.4
• /
• pp.264-270
• /
• 2019

As a case study on aspect ratio behavior, Kaolin, zeolite, $TiO_2$, pozzolan and diatomaceous earth minerals are investigated using wet milling with 0.3 pai media. The grinding process using small media of 0.3 pai is suitable for current work processing applications. Primary particles with average particle size distribution D50, ${\sim}6{\mu}m$ are shifted to submicron size, D50 ${\sim}0.6{\mu}m$, after grinding. Grinding of particles is characterized by various size parameters such as sphericity as geometric shape, equivalent diameter, and average particle size distribution. Herein, we systematically provide an overview of factors affecting the primary particle size reduction. Energy consumption for grinding is determined using classical grinding laws, including Rittinger's and Kick's laws. Submicron size is obtained at maximum frictional shear stress. Alterations in properties of wettability, heat resistance, thermal conductivity, and adhesion increase with increasing particle surface area. In the comparison of the aspect ratio of the submicron powder, the air heat conductivity and the total heat release amount increase 68 % and 2 times, respectively.

• Journal of Korean Medicine Rehabilitation
• /
• v.29 no.4
• /
• pp.1-14
• /
• 2019

Objectives The object of this study was to assess the effect of Gyejibokryunghwan (GBH) on anti-oxidant and anti-inflammatory activities in RAW 264.7 cells and on factors associated with fracture union in tibia-fractured rats. Methods The 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging activity was measured to assess anti-oxidant activity. The production of nitric oxide (NO), interleukin-6 (IL-6), interleukin-$1{\beta}$ ($IL-1{\beta}$) and tumor necrosis factor-${\alpha}$ ($TNF-{\alpha}$) in the RAW 264.7 cells were measured to assess anti-inflammatory activity. The production of osteocalcin, calcitonin, carboxy-terminal telepeptides of type II collagen (CTXII), transforming growth factor-${\beta}$ ($TGF-{\beta}$), bone morphogenetic protein-2 (BMP-2) in serum of tibia-fractured rats were measured to assess the effects of fracture union. X-rays were taken every two weeks from 0 to 4th week to assess fracture union effect. Results DPPH radical scavenging activity of GBH was increased according to concentration of GBH in RAW 264.7 cell. NO, prostaglandin $E_2$ ($PGE_2$), IL-6, $IL-1{\beta}$ and $TNF-{\alpha}$ were significantly decreased, indicating anti-inflammatory effect. Osteocalcin, calcitonin, $TGF-{\beta}$ were significantly increased in the experimental groups. CTXII was significantly decreased in the experimental groups. BMP-2 was not significantly changed in the experimental groups. The X-ray showed that the experimental group has better healing effects on tibia-fractured rats than control group. Conclusions From above result, GBH has an effect on anti-oxidant, anti-inflammatory activities in RAW 264.7 cells. GBH showed significant results in factors related with fracture union and radiologic examination. In conclusion, GBH can help fracture union and it well be expected to be used actively in clinics.

• Communications of the Korean Mathematical Society
• /
• v.27 no.2
• /
• pp.257-264
• /
• 2012

Exton introduced 20 distinct triple hypergeometric functions whose names are $X_i$ (i = 1, ${\ldots}$, 20) to investigate their twenty Laplace integral representations whose kernels include the confluent hypergeometric functions $_0F_1$, $_1F_1$, a Humbert function ${\Psi}_1$, and a Humbert function ${\Phi}_2$. The object of this paper is to present 18 new integral representations of Euler type for the Exton hypergeometric function $X_8$, whose kernels include the Exton functions ($X_2$, $X_8$) itself, the Horn's function $H_4$, the Gauss hypergeometric function $F$, and Lauricella hypergeometric function $F_C$. We also provide a system of partial differential equations satisfied by $X_8$.

• Journal of the Korean Ceramic Society
• /
• v.29 no.4
• /
• pp.259-264
• /
• 1992

The crystal structures and the bonding characteristics in $(Ba_xPb_{1-x})TiO_3$ have been investigated by X-ray diffraction analysis and infrared spectrophotometry. As $Ba^{2+}$ ion in $BaTiO_3$ were substituted by $Pb^{2+}$ ion, the structures were changed to orthorhombic from tetragonal, and also the covalent character in Ti-O bond increased, and then the dielectric constants decreased gradually. In the mixed oxide containing $Pb^{2+}$ ion more than 50%, the change-transfer energy of titanium ion increased.