• Title/Summary/Keyword: Angle of twist

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Optically compensated bend cell with pixel-isolating polymer wall for a flexible display application

  • Lee, Seong-Ryong;Lee, Joong-Ha;Jang, Hong-Jeek;Jo, Jin-Seok;Yoon, Tae-Hoon;Kim, Jae-Chang
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.207-210
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    • 2007
  • We fabricated an optically compensated bend cell with pixel-isolating polymer wall. The polymer wall was formed by phase separation of LCs and UVcurable polymer. The fabricated cell had initially ${\pi}-twist$ state. It showed low driving voltage, wide viewing angle and fast response properties. Also, polymer wall provided the mechanical stability preventing distortion of a display image from pressure.

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Numerical Analyses of Three-Dimensinal Thermo-Fluid Flow through Mixing Vane in A Subchannel of Nuclear Reactor (원자로 부수로내 혼합날개를 지나는 삼차원 열유동 해석)

  • Choi S.C.;Kim K.Y.
    • 한국전산유체공학회:학술대회논문집
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    • 2002.05a
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    • pp.79-87
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    • 2002
  • The present work analyzed the effect of mixing vane shape on the flow structure and heat transfer downstream of mixing vane in a subchannel of fuel assembly, by obtaining velocity and pressure fields, turbulent intensity, flow-mixing factors, heat transfer coefficient and friction factor using three-dimensional RANS analysis. NJl5, NJ25, NJ35, NJ45, which were designed by the authors, were tested to evaluate the performances in enhancing the heat transfer. Standard $\kappa-\epsilon$ model is used as a turbulence closure model, and, periodic and symmetry conditions are set as boundary conditions. The flow blockage ratio is kept constant, but the twist angle of mixing vane is changed. The results with three turbulence models( $\kappa-\epsilon$, $\kappa-\omega$, RSM) were compared with experimental data.

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Nonlinear finite element analysis of torsional R/C hybrid deep T-beam with opening

  • Lisantono, Ade
    • Computers and Concrete
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    • v.11 no.5
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    • pp.399-410
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    • 2013
  • A nonlinear finite element analysis of R/C hybrid deep T-beam with web opening subjected to pure torsion is presented. Hexahedral 8-nodes and space truss element were used for modeling concrete and reinforcement. The reinforcement was assumed perfectly bonded to the corresponding nodes of the concrete element. The constitutive relations for concrete and reinforcement are based on the modified field theory and elastic perfectly plastic. The smear crack approach was adopted for modeling the crack. The torque-twist angle relationship curve based on the finite element analysis was compared to the experimental results. The comparison shows that the curve of torque-twist angle predicted by the nonlinear finite element analysis is linear before cracking and close to the experimental result. After cracking, the curve becomes nonlinear and stiffer compared to the experimental result.

The analysis of Yurchenko's 900 Degree Twist Technique with Stretched Body (도마 Yurchenko 몸 펴 900도 비틀기 기술 분석)

  • Yeo, Hong-Chul
    • Korean Journal of Applied Biomechanics
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    • v.16 no.4
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    • pp.165-173
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    • 2006
  • The purpose of this study was to analyze Yurchenko's 900 degree twist technique between the highly scored and the lowly scored subjects during the 2003 TaeGu Universiad Championship. The following results was obtained by analyzing horizontal, vertical and resultant velocities on 1st, 2nd, 3rd and 4th phases. The highly scored subject took longer total performance time but shorter time in 2nd and 300 phases. The highly scored subject also took longer performance time in 4th phase. In the board contact phase the highly scored subject had bigger elbow joint angle and shoulder joint angle. The highly scored subject had longer flying time and had more higher vertical height but lower horizontal and resultant velocities on 4th phase.

A Single Gap Transflective Display using Fringe Field Switching Mode (FFS(Fringe Field Switching)모드를 이용한 단일갭 반투과형 액정 디스플레이)

  • Chin, Mi-Hyung;Jeong, Eun;Lim, Young-Jin;Lee, Seung-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.388-389
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    • 2007
  • A transflective liquid crystal displays driven by fringe field switching mode of new concept is being suggested. The FFS mode is known to have the different twist angle distribution at the position when an operating voltage is applied. We make the cell design by using the different twist angle which has some region decided on transmissive region and other region used to reflective region. By optimizing simulation condition in the concept, we proposed new tansflective LCDs using FFS mode with single gap and single gamma characteristics.

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A New Method for Measuring Azimuthal Anchoring Energy of Rubbed and UV-Exposed Polyimide Alignment Layers

  • Park, H.J.;Lee, W.K.;Kim, D.G.;Shin, D.C.;Woo, J.W.;Shin, H.H.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08b
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    • pp.1619-1621
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    • 2007
  • Novel optical measurement systems and improved cell configurations for measuring of azimuthal anchoring energies were developed. The difference between the mechanical rubbing direction and the optical easy axis that caused errors in the previous azimuthal anchoring energy measurement was compensated. In addition, the measurement accuracy of the twist angle and therefore the azimuthal anchoring energy was greatly enhanced. As a result, we were able to obtain valid azimuthal anchoring energy values for different alignment layers.

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Analysis of the Drag Angle in Cone Drum False Twisting Mechanism

  • Lee, Choon-Gil
    • Fashion & Textile Research Journal
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    • v.3 no.5
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    • pp.473-478
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    • 2001
  • The newly developed cone drum twister is one of the outer surface contacting friction-twisting devices in false-twist texturing. An investigation of the drag angle for the newly developed cone drum twister texturing mechanism is reported. An analysis is given from which equations can be derived that relate to the conical angle of cone drum, wrapping angle, drag angle, and yam helix angle. Theoretical values of drag angle are calculated and discussed. It is shown that, as the helix angle and the projected wrapping angle increases, the drag angle also increases slowly until the helix angle of $40^{\circ}$ but after the helix angle of $40^{\circ}$ the drag angle increases rapidly. Furthermore the higher the projected wrapping angle and conical angle, the higher the drag angle of friction surface.

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Study on The Estimation Method of the Joint for the Operation of the Upper Limb Rehabilitation Equipment for Hemiplegic Patients II (편마비 환자의 상지 재활 기기 운용을 위한 관절 각 추정 기법에 관한 연구 II)

  • Song, K.S.;Eom, S.H.;Lee, E.H.
    • Journal of rehabilitation welfare engineering & assistive technology
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    • v.8 no.4
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    • pp.313-318
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    • 2014
  • In this paper, we propose a method for correcting the measurement axis twist that occurs in the process of wearing and each estimation method of joint in which the inertial measurement unit based in health arm by the method of operation upper limb rehabilitation equipment of hemiplegic patients. In order to verify the proposed method, it is fitted with a inertial measurement unit of the upper arm and forearm of the experimenter left arm, verified by comparing actual joint angle is detected by photographing the arbitrary posture, the angle that the estimated joint. Then, it was verified by comparing the applied front / rear techniques for correcting the measurement axis twist. A result of the experiment, before applying the measurement axis twist correction, joint, after but each match rate showed a weak concordance rate in 89.16% and were corrected, measurement axis twist, each concordance rate of joint agreement of 93.28% I understand that it has been 4.12% improvement in the rate.

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Chemically Induced Zigzag Migration in Alumina Bicrystals (알루미나 쌍결정에서 조성변화에 의한 Zigzag Migration)

  • 백용균;강석중
    • Journal of the Korean Ceramic Society
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    • v.32 no.10
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    • pp.1117-1122
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    • 1995
  • The effect of grain boundary structure on zigzag migrtion has been studied. Five kinds of a(2110)-m(1010) diffusion couples with different twist angles by 30$^{\circ}$from a [0001] common direction of each plane were prepared. When chromia (Cr2O3) was added to the diffusion couples by a vapor phase, zigzag migration of the grain boundary occurred. The fraction of zigzag migration did not essentially vary with the twist angle, but the magnitude and migration distance of individual migrating segment varied. The variation of CIGM morphology thus appears to result from the change in grain boundary mobility due to microscopic deviation of grain boundary structure out of a macroscopic grain boundary orientation.

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Uniform bend transition and twist retention time improvement in a bistable chiral splay nematic liquid crystal cell

  • Kang, Sang-Ho;Jhun, Chul-Gyu;Lee, Seong-Ryong;Kim, Jae-Chang;Yoon, Tae-Hoon
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.1173-1176
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    • 2004
  • In a previous work we reported the bistable property by doping a chiral material in a splay cell. The bistable states are the splay state and the metastable 180$^{\circ}$twist state. The retention time of the metastable state can be changed by the variation of d/p (cell gap over pitch), cell gap, pretilt angle, azimuthal anchoring force, liquid crystal material, and so on. In this paper we will present uniform bend transition and twist retention time improvement in a multi-domain BCSN LC cell by using the multi cell gap method.

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