• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2002년도 춘계학술발표대회 논문집
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• pp.57-60
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• 2002

The stiffness model has been proposed to predict elastic constants of twisted yarn composites. The model is based upon the unit cell structure, the coordinate transformation, and the volume averaging of compliance constants for constituent materials. For the correlation of analytic results with experiments, composite samples of various yarn twist angle were tested. The samples were fabricated by the RTM process using glass yarns and epoxy resin. The correlations of elastic constants showed relatively good agreements. The model provides the predictions of the three-dimensional engineering constants, which are valuable input data for the analytic characterization of textile composites made of twisted yarn.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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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.

• 한국운동역학회지
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• 제16권4호
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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.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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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.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2002년도 춘계 학술대회논문집
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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.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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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.

• Computers and Concrete
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• 제11권5호
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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.

• 한국의류산업학회지
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• 제3권5호
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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.

• 재활복지공학회논문지
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• 제8권4호
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• pp.313-318
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• 2014

본 논문은 편마비환자들의 상지재활 기기 운용방법으로 건측에서 관성측정장치를 기반으로 한 관절각 추정 기법과 착용 과정에서 발생하는 측정축 뒤틀림을 보정하는 기법을 제안한다. 제안하는 기법을 검증하기 위해 실험자 왼팔의 상완과 전완에 관성측정장치를 부착하였으며, 임의의 자세를 촬영하여 검출한 실제 관절 각과 관절각 추정한 각과 비교하여 검증 하였다. 그리고 측정축 뒤틀림을 보정하는 기법을 적용 전/후를 비교하여 검증하였다. 실험 결과 측정축 뒤틀림 보정을 적용전은 관절각 일치율이 89.16%로 저조한 일치율을 보였으나, 측정축 뒤틀림을 보정한 후에 관절각 일치율은 93.28%의 일치율로 4.12% 개선되었음을 확인 하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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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.