• 제목/요약/키워드: Twisted

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Liquid Crystal Alignment Effect on the Inorganic Thin Film by Sputtering and using Ultraviolet Exposure Mothod

  • Hwang, Jeoung-Yeon;Kang, Hyung-Ku;Seo, Dae-Shik;Oh, Byeong-Yun;Ham, Moon-Ho;Myoungr, Jae-Min
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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    • pp.460-463
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    • 2005
  • We studied the nematic liquid crystal (NLC) alignment capability by the Ultraviolet (UV) alignment method on a a-C:H thin -film , and investigated electro-optical performances of the UV aligned twisted nematic (TN)- liquid crystal display (LCD) with the UV exposure on a-C:H thin film surface. A good LC alignment by UV irradiation on a a-C:H thin -film surface was achieved. Monodomain alignment of the UV aligned TN-LCD can be observed. The good electro-optical (EO)characteristics of the UV aligned TN-LCD was observed with oblique UV exposure on the a-C:H thin film surface for 1min.

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ATM 기반 HDSL 개발, 동 선로 상의 성능 평가 및 서비스 구현 (A System Development, Performance Assessment, and Service Implementation of ATM-based High-rate Digital Subscriber Line (HDSL))

  • 양충열
    • 한국통신학회논문지
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    • 제23권6호
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    • pp.1562-1574
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    • 1998
  • 본 논문에서는 ATM(Asynchronous Transfer Mode) 교환기 시스템에 T1, E1 및 부분적으로 E1급 속도의 중 저속 HDSL(High-rate digital subscriber line) 정합 기능을 개발하고, 근단누화(NEXT), 임펄스. 선로 잡음(power line noise) 및 접지 임피던스(longitudinal) 잡음 같은 주요 전송 손실이 존재하는 0.4 mm 및 0.5 mm의 기존 전화가입자 선로(UTP, Unshielded twisted pair)를 사용하는 CSA(Carrier serving areas) 선로 모델을 이용하여 $10^{-7}$의 BER(Bit error rates)의 전송 성능을 만족하기 위한 가입자 서비스 전송 거리 성능을 평가하였다. HDSL은 DSI, ISDN 기본 속도 접속 및 DLC 피더에 사용될 것이며 광 케이블과 인터페이스될 것이다. 또한, HDSL 시잔 전망을 제시한다.

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쌍안정 TN LCD의 고속 매트릭스 어드레싱을 위한 패널 파라미터와 구동 파형의 최적화 (Optimization of panel parameters and drive signals for high-speed matrix addressing of a bistable twisted-nematic LCD)

  • 이기동;박구현;장기철;윤태훈;김재창;이응상
    • 한국광학회지
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    • 제9권6호
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    • pp.417-422
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    • 1998
  • 쌍안정 TN LCD를 매트릭스 어드레싱 구동을 할 때 패널 파라미터와 구동 파형을 최적화하는 방법을 제시하였다. 쌍안정 TN 액정 셀에서 데이터 전압이 광 수위칭 특성에 미치는 영향을 측정하였고 이를 이론적으로 모델링 하였다. 스위칭에 데이터 전압이 미치는 영향을 고려하기 위해 시간의 함수로써 weighting 함수를 도입하였다. Weighting 함수를 알아내면 최소의 데이터 펄스폭을 계산함으로써 멀티플렉싱 구동을 위한 최대의 구동 라인 수를 계산할 수 있다. 또한 패널 파라미터(예, d/p)를 변화 시키면서 테스트 셀을 구동하면 고속 동작을 위한 파라미터를 최적화할 수 있다. 이로부터 이론적 예측과 실험 결과가 잘 일치하는 것을 확인하였다.

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Role of Coverage and Vacancy Defect in Adsorption and Desorption of Benzene on Si(001)-2×n Surface

  • Oh, Seung-Chul;Kim, Ki-Wan;Mamun, Abdulla H.;Lee, Ha-Jin;Hahn, Jae-Rayng
    • Bulletin of the Korean Chemical Society
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    • 제31권1호
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    • pp.162-167
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    • 2010
  • We investigated the adsorption and desorption characteristics of benzene molecules on $Si(001)-2{\times}n$ surfaces using a variable-low temperature scanning tunneling microscopy. When benzene was adsorbed on a $Si(001)-2{\times}n$ surface at a low coverage, five distinct adsorption configurations were found: tight-binding (TB), standard-butterfly (SB), twisted-bridge, diagonal-bridge, and pedestal. The TB and SB configurations were the most dominant ones and could be reversibly interconverted, diffused, and desorbed by applying an electric field between the tip and the surface. The population ratios of the TB and SB configurations were affected by the benzene coverage: at high coverage, the population ratio of SB increased over that of TB, which was favored at low coverage. The desorption yield decreased with increasing benzene coverage and/or density of vacancy defect. These results suggest that the interaction between the benzene molecules is important at a high coverage, and that the vacancy defects modify the adsorption and desorption energies of the benzene molecules on Si(001) surface.

The Structural Engineering Design And Construction Of The Tallest Building In Europe Lakhta Center, St. Petersburg. Russia

  • Abdelrazaq, Ahmad;Travush, Vladimir;Shakhvorostov, Alexey;Timofeevich, Alexander;Desyatkin, Mikhail;Jung, Hyungil
    • 국제초고층학회논문집
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    • 제9권3호
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    • pp.283-300
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    • 2020
  • The Lakhta Center is a Multifunction Complex Development (MFCD) consisting of 1) an 86 story office tower rising 462 m above the ground to provide high-end offices for Gazprom Neft and Gazprom Group affiliates 2) a Multi-Function Building (MFB) that includes, a scientific/educational center, a sport center, a children's technopark, a planetarium, a multi-transformable hall, an exhibition center, shops, restaurants, and other public facilities 3) a Stylobate 4) "The Arch, which forms the main entrance to the tower, restaurants, and cafes 5) underground parking and 6) a wide range of large public plazas. While each of the MFCD buildings is technically challenging in its own right, the focus of the paper is to present the development and integration of the structural and foundation systems of the bowed, tapered, and twisted shape of the tower into the fabric of the tallest Tower in Europe.

Fluorescence Quenching of Norfloxacin by Divalent Transition Metal Cations

  • Park, Hyoung-Ryun;Seo, Jung-Ja;Shin, Sung-Chul;Lee, Hyeong-Su;Bark, Ki-Min
    • Bulletin of the Korean Chemical Society
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    • 제28권9호
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    • pp.1573-1578
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    • 2007
  • Fluorescence quenching of norfloxacin (NOR) by Cu2+, Ni2+, Co2+ and Mn2+ was studied in water. The change in the fluorescence intensity and lifetime was measured as a function of quencher concentration at various temperatures. According to the Stern-Volmer plots, the NOR was quenched both by collisions and complex formation with the same quencher. However, the static quenching had a more important effect on the emission. Large static and dynamic quenching constants support significant ion-dipole and orbital-orbital interactions between NOR and cations. The both quenching constants by Cu2+ were the largest among quenchers. Also, quenching mechanism of Cu2+ was somewhat different. The change in the absorption spectra due to the quencher provided information on static quenching. The fluorescence of NOR was relatively insensitive to both the dynamic and static quenching compared with other quinolone antibiotics. This property can be explained by the twisted intramolecular charge transfer.

Peak Pressures Acting on Tall Buildings with Various Configurations

  • Bandi, Eswara Kumar;Tanaka, Hideyuki;Kim, Yong Chul;Ohtake, Kazuo;Yoshida, Akihito;Tamura, Yukio
    • 국제초고층학회논문집
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    • 제2권3호
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    • pp.229-244
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    • 2013
  • Twenty six pressure models of high rise buildings with various cross-sections including twisted models were tested in a boundary layer wind tunnel. The cross-sections were triangular, square, pentagon, hexagon, octagon, dodecagon, circular, and clover. This study investigates variations in peak pressures, and effects of various cross-sections and twist angles on peak pressures. To study the effects of various configurations and twist angles on peak pressures in detail, maximum positive and minimum negative peak pressures at each measurement point of the building for all wind directions are presented and discussed. The results show that peak pressures greatly depend on building cross-section and twist angle.

Electrospinning법으로 제조된 PZT 섬유의 구조분석 및 특성평가 (Structural Analysis and Characterization of PZT Fiber Fabricated by Electrospinning)

  • 박춘길;윤지선;정영훈;남중희;조정호;백종후;정대용
    • 한국세라믹학회지
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    • 제50권6호
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    • pp.466-469
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    • 2013
  • Currently, piezoelectric ceramics are being applied in various fields, such as ultrasonic sensors, vibration devices, sound filters, and various energy conversion devices. Flexible piezoelectric ceramics are widely studied in an effort to mitigate the disadvantages of their brittle and inductile properties. Structural damage to piezoelectric fibers is much less than that to thin films when piezoelectric fibers are twisted or bent. Therefore, stretchable devices can be fabricated if piezoelectric fibers are obtained using an elongated substrate. In this study, sintering processes of PZT ($Pb(Zr_{0.53}Ti_{0.47})O_3$) fibers prepared by electrospinning were optimized through the TGA and XRD analyses. The crystal structure and microstructure of the piezoelectric fibers were investigated by XRD, FE-SEM and TEM.

랜덤 위상변조가 가미된 이진 진폭 데이터 영상의 홀로그래픽 저장 특성 (Characteristics of holographic storage of random-phase-modulation-added binary amplitude data)

  • 오용석;신동학;장주석
    • 한국정보통신학회논문지
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    • 제5권2호
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    • pp.289-296
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    • 2001
  • 본 논문에서는 뒤틀린 니매틱 액정디스플레이를 가변적인 위상마스크로 사용하여 기존의 2진 데이터 영상에 위상변조를 추가하는 방법을 제안한다 이를 위해 액정디스플레이의 위상변조특성을 이론 및 실험적으로 조사하였고, 입사빔 세기가 매우 커지면 위상변조 특성이 변하는 현상이 존재함을 실험적으로 보였다. 위상변조가 가미된 2진 데이터 영상의 저장특성을 실험적으로 조사하기 위해 여덟 장의 홀로그램을 각다중 을 사용해서 Dupont 사의 광폴리머의 한 지점에 기록하였다. 위상변조를 사용하여 Fourier 면 홀로그램을 기록할 경우, 기존의 진폭변조방식만 사용하는 경우에 비해 빔세기 균일도를 높일 수 있어서, 같은 조건에서 더 많은 홀로그램을 기록할 수 있음을 보였다.

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자수 도전사(傳導絲) 기반의 유아체온 센싱 시스템 설계 연구 (A Design of Infant's Body Temperature Sensing System Based on Embroidery Textile Conductive Wire)

  • 송하영;이강휘;이정환
    • 전기학회논문지
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    • 제65권5호
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    • pp.862-867
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    • 2016
  • In this study, the embroidery textile conductive wire of conductive yarn was designed into the wearable integrated clothing for sensing the infant's body temperature. To develop a high quality of the stable fiber-based textile conductive wire, firstly the five types of conductive yarns were twisted or covering polyester yarns and the coated conductive fiber with silver(Ag) or iron(Fe). As a result of comparative conductivity in conductive yarns of yarn processing, the 250 denier of conductive yarns with $0.74{\Omega}$/1~5cm were proposed and used for the integrated embroidery textile conductive wire for sensing. During experiments using the proposed embroidery textile conductive wire, measured resistance of thermistor according to the body temperature was correctly delivered to amplifier module, and showed feasible reliability of temperature sensing. As a wearable application, conductive yarns which takes forms of embroidery textile conductive wire would seems to be reliable as a conductive wire and could be replaced by the conductive metal wires.