• Title/Summary/Keyword: alignment

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통신방송위성 안테나 얼라인먼트 측정

  • Yoon, Yong-Sik;Park, Hong-Chul;Son, Young-Seon;Lee, Byoung-Gi
    • Aerospace Engineering and Technology
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    • v.3 no.1
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    • pp.117-125
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    • 2004
  • The three-dimensional precision measurement technology for industrial product of middle and/or large scale has been developed. Theodolite measurement system which is one of the technology is widely used in aerospace industry. This paper describes a range alignment method of parabolic antenna to RF probe in the near field range by using the theodolite system. The range alignment of the Ku-band and Ka-band antennas has been accomplished within the requirements, ±1 mm and ±$0.05^{circ}$.

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Study of the Photo-alignment Technique through the Surface Modification

  • Song, Dong-Mee;Shin, Dong-Myung
    • 한국정보디스플레이학회:학술대회논문집
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    • 2000.01a
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    • pp.197-198
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    • 2000
  • A surface-assisted photo-control of the liquid crystal (LC) alignment has been achieved by modifying the topmost surface of the polyimide film with photo-reactive molecules. Recently, photo-alignment technique using a thin film of poly(vinyl cinnamates) have been reported. However their commercial potentiality is limited by their low thermal stability. To enhance thermal stability, we synthesized the chalcone derivatives as the photo-reactive molecules and introduced the materials on the surface-modified polyimide film.. We identified that the photo-chemical reaction of the chalcone derivatives occur in few minutes with irradiation of UV light. The photo-alignment characteristics of the modified polyimide films treated by polarized UV light and their LC cells are investigated as a function of exposure dose.

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Tilted Homeotropic Alignment using Ion Beam Process; Development of Novel Inorganic thin films

  • Hwang, Byoung-Har;Kim, Kyung-Chan;Ahn, Han-Jin;Kim, Jong-Bok;Baik, Hong-Koo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.450-452
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    • 2005
  • The ion beam alignment technique is one of the potential and fascinating methods. However, there are merely a few reports about aligning nematic liquid crystals (NLCs) horizontally for in-plane switching mode (IPS) by means of low energy ion beam exposure on inorganic materials such as DLC. In this study, we have investigated the tilted vertical alignment of NLC by the ion beam technique on the thin films of various amorphous silicon compounds as new inorganic alignment materials. Appropriate pretilt angles of NLC with preferred orientation on these thin films were achieved. And the electro-optic property of vertically aligned single domain cells has been investigated.

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Soft-lithography for Preparing Patterned Liquid Crystal Orientations

  • Kim, Hak-Rim;Jung, Jong-Wook;Shin, Min-Soo;Kim, Myung-Eun;Lee, You-Jin;Kim, Jae-Hoon
    • Journal of Information Display
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    • v.8 no.2
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    • pp.5-9
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    • 2007
  • We demonstrate novel soft-lithographic techniques for preparing patterned liquid crystal (LC) orientations at an alignment layer. By controlling patterning conditions such as wetting property and operating temperature depending on polymeric materials, multi-directional or modified LC alignment conditions can be simply achieved.

A Study on Optimum Shaft Alignment Analysis for VLCC (VLCC의 최적 축계정렬해석 연구)

  • Kim Hyu Chang;Kim Jun Gi
    • Special Issue of the Society of Naval Architects of Korea
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    • 2005.06a
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    • pp.134-137
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    • 2005
  • Recently, in VLCC, shafting system is stiffer due to large engine power whereas hull structure is more flexible due to scantling optimization, which can be suffered from alignment damage by incompatibility between shafting and hull, In this study, shafting system without stern tube forward bush was adapted for less sensitive system against external factors. Also, shaft alignment analysis was considered with hull deflection at various ship loading conditions and stern tube after bush of long journal bearing was evaluated by static squeezing pressure and dynamic oil film pressure with sloping control. Whirling vibration was also reviewed to avoid resonance with propeller blade order. So, reliable shafting design for VLCC could be achieved through optimized alignment analysis for the system without stern tube forward bush.

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Study of the Effect of Crankshaft Model in Shaft Alignment Analysis (추진축계 정렬해석에서 엔진내부 축 모델의 영향에 관한 연구)

  • Kim Kwang Seok;Yeun Jung Hum;Kang Joong Kyoo;Heo Joo Ho
    • Special Issue of the Society of Naval Architects of Korea
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    • 2005.06a
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    • pp.206-210
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    • 2005
  • As design trends has changed to have flexible aft hull structure, increased power output and stiffer shafting system, owners and classification societies have more concerned about shaft alignment. In the shaft alignment analysis, there are many uncertainties which are related in propeller generated force, bearing stiffness, crank shaft model and etc. in this study, it is focused on the effect of crankshaft model by comparing between equivalent model and actual crankshaft model.

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Photo-alignment of Low-molecular Mass Nematic Liquid Crystals on Photochemically Bifunctional Chalcone-epoxy Film by Irradiation of a Linearly Polarized UV Light

  • Choi, Dong-Hoon;Cha, Young-Kwan
    • Bulletin of the Korean Chemical Society
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    • v.23 no.4
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    • pp.587-592
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    • 2002
  • Photocrosslinkable chalcone-epoxy compound comprising 1,3-bis-(4-hydroxy-phenyl)-propenone was synthe-sized for fabricating the photo-alignment layer of liquid crystals. Chalcone group was introduced into the main chain unit of the epoxy oligomer. We observed a photodimerization behavior and an optical anisotropy of this material by irradiation of a linearly polarized UV(LP-UV) light. With a trace amount of cationic photoinitiator (TRS-HFA), polymerization of epoxy groups was also conducted at the similar wavelength range used for photodimerization. Linearly polarized UV irradiation on the chalcone-epoxy films with cationic photoinitiator induced optical anisotropy of the film and the resultant film can be used for alignment layers for low molecular weight nematic liquid crystals.

New Cellulose-Based Photopolymer with High Thermal and UV Stability

  • Cho, Han-Dong;Park, Seo-Kyu;Jhun, Chul-Gyu;Kwon, Soon-Bum;Kurioz, Yu.;Reznikov, Yu.;Gerus, I.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.853-856
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    • 2007
  • We report on the alignment properties of new cellulose based photopolymer. The LC alignment quality and image sticking property of the TN and IPS cells made by using the photopolymer were investigated. Thermal and UV stability of those properties were also investigated. Excellent LC alignment quality and stability were obtained particularly in IPS mode.

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Advanced Nanoimprinting Material for Liquid Crystal Alignment

  • Gwag, Jin-Seog;Oh-e, Masahito;Yoneya, Makoto;Yokoyama, Hiroshi;Satou, H.;Itami, S.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.534-537
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    • 2007
  • To promote liquid crystal application of nanoimprint lithography, a polymer with new concept is proposed. The material consists of a polyamic acid for good LC alignment and an epoxy resin for good imprinting. The result of sum-frequency generation (SFG) vibrational spectroscopy proves that this material is a functionally gradient material. This material shows excellent capability as a nanoimprinting material as well as an LC alignment layer.

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A Simple and Fast Web Alignment Tool for Large Amount of Sequence Data

  • Lee, Yong-Seok;Oh, Jeong-Su
    • Genomics & Informatics
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    • v.6 no.3
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    • pp.157-159
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    • 2008
  • Multiple sequence alignment (MSA) is the most important step for many of biological sequence analyses, homology search, and protein structural assignments. However, large amount of data make biologists difficult to perform MSA analyses and it requires much computational time to align many sequences. Here, we have developed a simple and fast web alignment tool for aligning, editing, and visualizing large amount of sequence data. We used a cluster server installed ClustalW-MPI using web services and message passing interface (MPI). It also enables users to edit multiple sequence alignments for manual editing and to download the input data and results such as alignments and phylogenetic tree.