• Title/Summary/Keyword: anchoring effect

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A Study on the Lubrication Characteristics of Liquid Crystals (액정의 윤활특성에 관한 연구)

  • 임윤철;민지홍
    • Tribology and Lubricants
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    • v.8 no.1
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    • pp.30-37
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    • 1992
  • The displacement and pressure field of liquid crystals are analyzed numerically and compared with classical Reynolds theory. A plane slider bearing is employed as a simple example considering elasticity, permeability and splay effect which are the inherent characteristics of layered liquid crystals. Due to the geometric constraint of thin wedge and the strong anchoring behavior of the liquid crystals dislocations are inevitable. A finite element method is used to solve five coupled nonlinear equations. The load characteristics based on the pressure distribution along the gap shows that the liquid crystals can carry large load compared to the conventional lubricants.

Birefringence effect of two directionally rubbed liquid crystal cells

  • Huang, Chi Yen;Huang, Yao Sheng;Tian, Jing Rui
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.446-449
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    • 2005
  • The alignment property of liquid crystals on the two-easy axes substrate is investigated. The two-easy axes substrate frustrates the orientation of the LCs next to the substrate, and hence influences the birefringence of the LC cell. Experimental findings reveal that the ratio of the rubbing strengths in the different rubbing directions and the cell thickness substantially influence the birefringence of the LC cell. The surface anchoring energetic competition between the different rubbing directions contributes to the observed results.

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A Case of Pedicle Screw Loosening Treated by Modified Transpedicular Screw Augmentation with Polymethylmethacrylate

  • Kang, Suk-Hyung;Kim, Kyoung-Tae;Park, Seung-Won;Kim, Young-Baeg
    • Journal of Korean Neurosurgical Society
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    • v.49 no.1
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    • pp.75-78
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    • 2011
  • We report a case of pedicle screw loosening treated by modified transpedicular screw augmentation technique using polymethylmethacrylate(PMMA), which used the anchoring effect of hardened PMMA. A 56-year-old man who had an L3/4/5 fusion operation 3 years ago complained of continuous low back pain after this operation. The computerized tomography showed a radiolucent halo around the pedicle screw at L5. We augmented the L5 pedicle screw with modified pedicle screw augmentation technique using PMMA and performed an L3/4/5 pedicle screw fixation without hook or operation field extension. This modified technique is a kind of transpedicular stiffness augmentation using PMMA for the dead space around the loosed screw. After filling the dead space with 1-2 cc of PMMA, we inserted a small screw. Once the PMMA hardened, we removed the small screw and inserted a thicker screw along the existing screw threading to improve the pedicle screws' pullout strength. At 10 months' follow-up, x-ray showed strong fusion of L3/4/5. The visual analogue scale (VAS) of his back pain was improved from 9 to 5. This modified transpedicular screw augmentation with PMMA using anchoring effect is a Simple and effective surgical technique for pedicle screw loosening. However, clinical analyses of long-term follow-up and biomechanical studies are needed.

Periodic Boundary Effect on Multi-Domain Formation in Liquid Crystal Devices

  • Yu, Chang-Jae;Park, Jae-Hong;Kim, Jin-Yool;Jung, Min-Sik;Lee, Sin-Doo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.478-481
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    • 2003
  • We studied a periodic boundary effect in liquid crystal (LC) devices with multi-domains consisting of homeotropic and hybrid alignments. In this configuration, the surface anchoring energy was determined using the LC director-distorted length near the domain boundary, in a linear approximation of the director profile based on the continuum theory. The distorted length was measured in the LC binary diffraction grating.

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Director gliding on photoaligning surfaces

  • Reznikov, Yuri;Buluy, Olexander;Kurioz, Yuriy;lljin, Andery;Ouskova, Elena;Antonova, K.;Nobili, Maurizio
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.764-767
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    • 2005
  • Photoaligning polymers usually possess "sofe" surface, containing flexible groups and provide relatively small anchoring energy($W<10^{-2}$ erg $cm^{-2}$). In this case field-induced reorientation of director on the aligning surface is essential. We have shown that surface director reorientation can modify the aligning surface and result in gliding of the axis of easy orientation of LC. this phenomena together with adsorption/desorption of ions in electric field cause strong sticking effect in LCDs photoaligning materials. We proposed a method of decreasing of the sticking effect based on irradiation of the photoaligning surface by an unpolarized light.

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Liquid crystal alignment and EO performance of transcription-aligned TN-LCD (전사배향 TN-LCD의 액정배향 및 전기광학특성)

  • 서대식;김진호
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.11 no.12
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    • pp.1133-1138
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    • 1998
  • In this paper, we obtained the monodomain alignment of nematic liquid Crystal(NLC) in the cell fabricated by transcription alignment method on polyimide(PI) surface with side chain. It is considered that the LC alignment produced by the transcription alignment method is attributed to a memory effect of the NLC on PI surfaces. Also we observed that the generated pretilt angle of NLC is about $3.7^{\circ}$ with transcription alignment on PI surface. Next, we measured that the voltage-transmittance characteristics of transcription-aligned TN-LCD are almost same compared to rubbing-aligned TN-LCD. Also, we measured that the curve of transcription-aligned TN-LCD is less sharp than that of the rubbing-aligend TN-LCD in the decay time characteristics. It is considered that the response time characteristics of transcription-aligned TN-LCD are attributed to the weak anchoring strength between the LC molecules and the polymer surface.

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A Study on the Experience Effect of Engine Drivers (철도기관사의 경험효과에 관한 연구)

  • 김충수;안승호
    • Proceedings of the KSR Conference
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    • 1999.11a
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    • pp.73-80
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    • 1999
  • Belief revision involves integrating new information with the current belief. It is a ubiquitous human activity. A critical feature of belief revision lies in its sequential nature. Railroad system can be described as organic. Engine drivers take a great role in this system. Recently, Hogarth and Einhorn(1992) have Posited a belief-adjustment model for updating beliefs. Based on a sequential anchoring and adjustment strategy, the model is important fro decision makers. The sequential nature of information processing is affected by some task variables. This will be mainly explained in this paper. The purpose of this study is to examine the engine drivers' belief revision process and factors which influence on the belief revision process. The factors are the order and the experience. Thereby, this will contribute to the study of engine drivers' behavior. The result of this study is summarized as follows. The order effect due to the order of presentation of the evidence exist. The difference of belief revision is due to The experience level.

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Effect of Cognitive-Bias (Anchoring Bias) to N. Korea on Reunification Perception (북한에 대한 인지편향(기준점편향) 이 통일인식에 미치는 영향)

  • Han, Seung Jo;Bae, Young Min
    • Convergence Security Journal
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    • v.21 no.1
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    • pp.201-208
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    • 2021
  • The purpose of this study is to investigate reunification perception among groups with different cognitive bias(anchoring bias) through empirical studies. This study assumes that cognitive bias occurs according to the content of N. Korea provided in school education, and that the cognitive bias formed in youth creates a difference in perception of N. Korea and reunification. For empirical study, a survey of reunification awareness conducted by the Institute for Peace an Unification Studies-Seoul National University was used, and the two groups are divided into A-group that chose "anti-communism or security" and B-group that did "reunification interests, multi-culturalism and understanding North Korea" according to N. Korea content which was encountered in school education during adolescence. A-group recognized N. Korea as a hostile target even after becoming an adult, while B-group regarded N. Korea as a one of dialogue and cooperation. This analysis illustrates the existence of cognitive bias between the two groups because of N. Korea content which was given in school education. A-group had a lower percentage than B-group in terms of the benefits of reunification to S. Korea and the need for more dialogue and compromise with N. Korea. However, there was no difference between two groups in terms of acceptance of N. Korean defectors. This research result could be a reference to the direction of school education policies relating to reunification in that early school education affects reunification awareness and perception related with N. Korea even in adulthood.

A Study of Electro-optical Characteristics of Full-HD LCOS Panel Depending on Various Cell Gaps (Full-HD LCOS Panel의 Cell Gap의 변화에 따른 전기광학적 특성에 대한 연구)

  • Son, Hong-Bae;Kim, Min-Seok;Kang, Jung-Won
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.46 no.8
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    • pp.6-11
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    • 2009
  • The electro-optical characteristics of the Liquid Crystal on Silicon (hereinafter "LCOS") micro-display on vertically alignment (VA) mode were studied with 3-dimensional LC code. 5 different cell gaps, such as 1.4 ${\mu}m$, 1.8 ${\mu}m$, 2.1 ${\mu}m$, 2.4 ${\mu}m$ and 2.8 ${\mu}m$, were selected. The reflectance-voltage (R-V) characteristics, distribution of reflected light, reflectance, optical fill factor and contrast ratio were calculated and investigated depending on various cell gaps. Due to the surface anchoring effect, higher cell gap showed higher reflectance. However, considering the optical fill factor and contrast ratio, middle-height 2.1 ${\mu}m$ showed the best electro-optical characteristic. 0.7 inch Full-HD LCOS panels having same geometry and material property were fabricated. The reflected light intensity and contrast ratio were measured and the measured results were well-matched to the calculated results.

The Effect of Cohesive Devices on Memory and Understanding of Scientific Text (응집장치가 과학텍스트의 기억과 이해에 미치는 효과)

  • 김세영;한광희;조숙환
    • Korean Journal of Cognitive Science
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    • v.13 no.2
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    • pp.1-13
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    • 2002
  • This Paper is concerned with the impact of linguistic markers of coherence, such as causal connectives. repetitions. and anchoring devices. on the comprehension of a scientific text in Korean. A scientific text on the process of lightning formation was selected. and two versions of the text were constructed by varying the strength of coherence. Eighty-two undergraduate students took Part in the experiment in which they were instructed to fill in the blanks in each text in a recall and a recognition task and to respond to a set of question in a comprehension test. The results of this experiment revealed a selective effect of the cohesive markers. It was found that the different linguistic signals seem to Play a facilitating role in varying degrees in accordance with the type of tasks involved Moreover an analysis of topic continuity from the beginning paragraphs through the last revealed that the text was better understood in the paragraphs containing the main topic better than those without it. This finding seems to indicate that the off-line processing of scientific text is not influenced solely by the local bottom-up processing alone The effect of topic continuity seems to suggest that a global. top-down processing effect has an important role to play. overriding the impact of cohesive devices.

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