• 제목/요약/키워드: ${\pi}?{\pi}$ interaction

검색결과 244건 처리시간 0.029초

IPS-LCD에서의 표면액정배향효과가 시야각 특성과 응답속도에 미치는 영향 (Improvement of the response time and embodiment of the viewing angle in IPS mode)

  • 최재학;서대식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1998년도 추계학술대회 논문집
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    • pp.65-68
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    • 1998
  • The mechanism of response time and viewing angle in in-plane switching ( IPS ) liquid crystal display ( LCD ) were investigated. The response time of photo-aligned IPS-LCD is fast compared with rubbing-aligned IPS-LCD on polyimide ( PI ) surface. The decay time $\tau$$\_$d/ is decreased with increasing the azimuthal anchoring energy A $\psi$ due to the steric interaction between the LC molecules and side chain of polymer. The viewing angle of IPS-LCD is increased by using photo-depolymerizatin method ; about ${\pm}$70$^{\circ}$at all direction.

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폴리이미드막을 이용한 광배향 효과에 관한 연구 (A Study on Effect of Photo-alignment in Nematic Liquid Crystal on Polyimide Film)

  • 서대식;황율연
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1997년도 춘계학술대회 논문집
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    • pp.116-119
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    • 1997
  • We investigated new type non-robbing liquid crystal (LC) alignment techniques in the cell with slanted non-polarized ultraviolet (UV) irradiation on polyimide (Pl) film. It is shown that the uniform alignment for nematic (N) LC is obtained by using slanted non-polarized UV irradiation on Pl surface. We successfully obtained that the pretilt ang1e of NLC is generated about 3 degree in the LC cells by using slanted non-polarized UV irradiation with 70 degree on Pl surface. We consider that the pretilt angle generation for NLC is attributed to interaction between the LC molecular and the PI surface. We conclude that the uniform LC alignment is attributed to anisotropic dispersion force effect due to photo depolymerization of polymer on Pl surface.

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폴리이미드막표면위에 경사진 자외선 조사를 이용한 액정셀에서의 고프리틸트각의 발생 (Generation of High Pretilt Angle in a Cell with Oblique non-polarized UV Light Irradiation on Polyimide Surface)

  • 서대식;한정민
    • 한국전기전자재료학회논문지
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    • 제11권6호
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    • pp.481-485
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    • 1998
  • We investigated the generation of high pretilt angle for nematic liquid crystal (NLC) in a cell with obilique non-polarized ultraviolet (UV) light irradiation on mixtured polyimide surface. It was found that the monodomain alignment of NLC is obtained with an angle of incidence of 75∼85 degrees on PI surface. We consider that the monodomain alignment of NLC is attributed to anisotropic dispersion force effect to photo-depolymerization of polymer. We successfully observed that the pretilt angle of NLC is generated above 5 degree with an angle of incidence of 75∼85 degrees. It is considered that the pretilt angle generation NLC is attributed to interaction between the LC molecules and the polymer surfaces.

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Phosphatidylinositol 3-Kinase Regulates Nuclear Translocation of NF-E2-Related Factor 2 through Actin Rearrangement in Response to Oxidative Stress

  • Kang, Keon-Wook;Lee, Seung-Jin;Park, Jeong-Weon;Kim, Sang-Geon
    • 대한약학회:학술대회논문집
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    • 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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    • pp.241.3-242
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    • 2002
  • Expression of phase II detoxifying genes is regulated by NF-E2-related factor 2 (Nrf2)-mediated antioxidant response element (ARE) activation. Phosphatidylinositol 3-kinase (PI3-kinase) plays an essential role in ARE-mediated rGSTA2 induction by oxidative stress and controls microfilaments and translocation of actin-associated proteins. This study was designed to investigate the P13-kinase-mediated nuclear translocation of Nrf2 and the interaction of Nrf2 with actin. (omitted)

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Transmission coefficients of a floating rectangular breakwater with porous side plates

  • Cho, Il-Hyoung
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제8권1호
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    • pp.53-65
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    • 2016
  • The interaction between incident waves and a floating rectangular breakwater with the vertical porous side plates has been investigated in the context of the two-dimensional linear potential theory. The matched eigenfunction expansion method(MEEM) for multiple domains is applied to obtain the analytic solutions. The dependence of the transmitted coefficients and motion responses on the design parameters, such as porosity and protruding depth of side plates, is systematically analyzed. It is found that the non-dimensional wavelength where the sudden drop of transmission coefficients occurs, corresponds to the heave resonant frequency obtained from Ruol et al. (2013) for $\pi$-type floating breakwater. It is concluded that both properly selected porosity and deeper protruding depth of side plates are helpful in reducing the transmission coefficients and also extending the wider applicable extent of incident wavelength for performance enhancement.

저항 점 용접공정의 최적제어 (Optimal control of resistance spot welding process)

  • 장희석;조형석
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국내학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
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    • pp.370-373
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    • 1988
  • Althouah there have been many attempts to control weld quality in resistance spot welding processes, design method for an on-line feedback controller based upon process dynamics has not been suggested. This is due to the fact that the resistance spot welding is a highly complicated process, whice involves the interaction of electrical, thermal, mechanical and metallurgical phenomena. In this paper, an optimal control method based on FDM model with shunt effect is presented, which can regulate the nugget size, at the same time minimizing the control heat input. Optimal PI gain of the controller were determined by numerical optimization. Simulation results show that, as a result of the proposed optimal control, the weld nugget can be made to approach a desired nugget size with less control heat input than that required for the conventional spot welding process in the face of the shunt effect.

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풍력터빈 토크제어의 특성 고찰 (A Study on Properties of Torque Control for Wind Turbine)

  • 임채욱
    • 제어로봇시스템학회논문지
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    • 제15권12호
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    • pp.1157-1162
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    • 2009
  • The aerodynamic torque and power caused by the interaction between the wind and blade of wind turbine are highly nonlinear. For this reason, the overall dynamic behaviors of wind turbine have nonlinear characteristics. The aerodynamic nonlinearity also affects properties of torque control for wind turbine. In this paper, the nonlinear aerodynamic property according to the wind speed below rated power and its effects on the torque control system are investigated. Nonlinear parameter representing change of aerodynamic torque with respect to rotor speed is obtained by linearization technique. Effects of this aerodynamic nonlinear parameter on the closed-loop torque system with PI controller for an 1.5 MW wind turbine are presented.

Roles of YAP in mediating endothelial cell junctional stability and vascular remodeling

  • Choi, Hyun-Jung;Kwon, Young-Guen
    • BMB Reports
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    • 제48권8호
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    • pp.429-430
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    • 2015
  • Angiogenesis is a complex process involving dynamic interaction of various cell to cell interactions. Endothelial cell interactions regulated by growth factors, inflammatory cytokines, or hemodynamic stress are critical for balancing vascular quiescence and activation. Yes-associated protein (YAP), an effector of Hippo signaling, is known to play significant roles in maintaining cellular homeostasis. However, its role in endothelial cells for angiogenic regulation remains relatively unexplored. We demonstrated the critical role of YAP in vascular endothelial cells and elucidated the underlying molecular mechanisms involved in angiogenic regulation of YAP. YAP was expressed in active angiogenic regions where endothelial cell junctions were relatively loosened. Consistently, YAP subcellular localization and activity were regulated by VE-cadherin-mediated PI3K/Akt pathway. YAP thereby regulated endothelial sprouting via angiopoietin-2 expression. These results provide an insight into a model of coordinating endothelial junctional stability and angiogenic activation through YAP. [BMB Reports 2015; 48(8): 429-430]

Purification and Characterization of Glyoxalase I from Chlamydomonas reinhardtii

  • Hwang, Sun-Jun;Chai, Young-Gyu
    • BMB Reports
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    • 제29권4호
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    • pp.294-299
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    • 1996
  • Glyoxalase I (Ee 4.4.1.5, lactoylglutathione lyase) from Chlamydomonas reinhardtii was purified to homogeneity by ammonium sulfate fractionation, anion-exchange chromatography, hydrophobic interaction chromatography, and affinity chromatography on S-hexylglutathione agarose. The purified enzyme was judged to be homogeneous on SDS-PAGE, and consisted of a single polypeptide chain with a relative molecular weight of 24,000. The enzyme was most active at $40^{\circ}C$ and pH 7.5. It was catalytically most active with methylglyoxal as substrate. A number of properties of the Chlamydomonas glyoxalase I enzyme, such as substrate specificity, molecular mass, kinetic parameters, pi, metal ion effect, have been determined and compared with those reported for preparations from other sources. It had somewhat different characteristics from mammalian enzymes.

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Adaptive Intelligent Control of Nonlinear dynamic system Using Immune Fuzzy Fusion

  • Kim, Dong-Hwa;Park, Jin-Ill
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제3권2호
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    • pp.146-156
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    • 2003
  • Nonlinear dynamic system exist widely in many types of systems such as chemical processes, biomedical processes, and the main steam temperature control system of the thermal power plant. Up to the present time, PID Controllers have been used to operate these systems. However, it is very difficult to achieve an optimal PID gain with no experience, because of the interaction between loops and gain of the PID controller has to be manually tuned by trial and error. This paper suggests control approaches by immune fuzzy for the nonlinear control system inverted pendulum, through computer simulation. This paper defines relationship state variables $x,\dot{x},{\theta},\dot{\theta}$ using immune fuzzy and applied its results to stability.