• 제목/요약/키워드: fiber-based devices

검색결과 104건 처리시간 0.026초

회전기와 첩 광섬유 격자를 이용한 가변 분산 보상기 (Tunable dispersion compensator based on chirped fiber bragg gratings with a mechanical rotator)

  • 김준희;배준기;한영근;김상혁;이상배;정제명
    • 한국광학회지
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    • 제15권2호
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    • pp.100-103
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    • 2004
  • 본 논문에서는 첩 광섬유 격자를 이용한 가변 분산 보상기를 소개한다. 개발된 가변 분산 보상기는 금속판의 벤딩에 의해 유도되는 인장력과 수축력에 대한 분석을 기반으로 첩광섬유 격자의 분산 값을 제어할 수 있도록 설계되었으며, 제작된 분산 보상기는 단순히 금속 원판의 회전만으로 광섬유 격자에 선형적인 인장력과 수축력을 유도하곤 중심파장의 이동이 없이 분산 값을 변화시킬 수 있었다. 분산 값은 회전각의 변화에 따라 228.04 ㎰/nm∼1430.7 ㎰/nm의 범위에서 분산 값을 제어할 수 있었다. 그리고 중심 파장의 이동은 0.03 nm미만이었다.

Electrical Properties of CNT and Carbon Fiber Filled Hybrid Composites Based on PA66

  • Lee, Minji;Park, Se-Ho;Jhee, Kwang-Hwan;Kye, Hyoungsan;Bang, Daesuk
    • Elastomers and Composites
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    • 제56권2호
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    • pp.65-71
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    • 2021
  • In recent times, the demand for electronic devices has increased because of advancements in the electronics industry. Consequently, research on shielding against electromagnetic interference (EMI) from electronic devices has also progressed significantly. In particular, research on imparting electrical conductivity to plastic has seen substantial progress. In this study, the effect of hybrid fillers comprising carbon fiber (CF) and carbon nanotubes (CNTs) on the electrical properties of polyamide 66 (PA66) composites was investigated. PA66 composites were prepared using a BUSS Co-Kneader single-screw extruder. EMI shielding effectiveness (SE) increased with the increasing addition of unsized CF (UCF), sized CF (SCF), and CNTs. For the PA66/SCF/CNT hybrid filler composites, EMI SE significantly increased with the increase in SCF content. Finally, the hybrid filler comprising SCF and CNTs may have a synergistic effect on the EMI SE and surface resistivity of PA66/SCF/CNT composites.

광섬유 기반 IPTV 네트워크를 위한 FC 내장형 IPTV STB 제안 (Suggestion of an Fiber Channel-Embedded IPTV STB for Optical Fiber-based IPTV Networks)

  • 정성욱
    • 한국정보전자통신기술학회논문지
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    • 제10권3호
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    • pp.213-219
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    • 2017
  • 최근, 인터넷 프로토콜 텔레비전 (IPTV) 서비스가 일반화되어 TV시청 뿐만 아니라 다양한 인터넷기반 서비스가 가능하다. 이러한 IPTV 시스템에서 STB(Set-Top Box)는 실시간 멀티미디어 콘텐츠를 송수신 할 수 있도록 지원하는 네트워크 단말 장치로써 작동한다. 이러한 IPTV 네트워크는 일반적으로 FTTH(Fiber-To-The-Home)와 같은 광섬유(Optical Fiber) 기반의 광대역기반 네트워크에 의해 제공되지만 현재 대부분의 IPTV STB는 대역폭(Bandwidth)을 공유하는 이더넷(Ethernet)과 같은 로컬 영역 네트워크(LAN)에 연결된 장치 중 하나로 연결된다. 따라서 HD급 고화질 콘텐츠 및 다양한 서비스 지원을 위한 IPTV STB을 위하서는 1Gbps와 같은 충분한 광섬유 기반의 네트워크 대역폭을 효과적으로 활용할 수 있어야 한다. 이를 위하여 본 논문에서는 광섬유 네트워크에 바로 장착할 수 있는 새로운 FC(Fiber Channel) 내장형 IPTV STB를 제안한다. 그 후 해당 제안된 FC 내장형 IPTV STB의 우수성을 확인하기 위하여 해당 FC 내장형 IPTV STB가 장착된 FC-AL(Fiber Channel-Arbitration Loop) 네트워크를 구성하여 해당 아키텍처의 성능을 검증한다. 우수한 IPTV 아키텍처의 성능을 확인하기 위하여 철저한 시뮬레이션을 통하여 평균 시작지연(Average Start-up Delay) 시간, 평균 거부비율(Average Reject Ratio) 및 동시 사용자수(Number of Concurrent Users)를 측정한다. 놀랍게도, 제안된 FC 내장형 IPTV STB가 장착된 IPTV 네트워크 아키텍처는 10 msec 미만의 우수한 평균 시작지연(Average Start-up Delay) 시간, 3 % 미만의 수용가능한(Acceptable) 평균 거부비율(Average Reject Ratio) 및 아키텍처를 확장 할 때 동시 사용자수의 선형증가(Linear Increase)를 보여준다. 이는 제안된 FC 내장형 STB가 광섬유 기반의 광대역 대역폭을 효과적으로 사용하여 전체 IPTV 네트워크 성능에 우수한 영향을 미치고 있음을 보여준다.

스마트 텍스타일 구현을 위한 OLED 기반 웨어러블 디스플레이 리뷰 (Review of OLED-based Wearable Display for Smart Textiles)

  • 정은교;이창민;조석호
    • 한국의류산업학회지
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    • 제23권6호
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    • pp.860-868
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    • 2021
  • Clothing has a very important role in human life, and it is the most human-friendly platform because humans wear it in almost all the time. In the recent years, smart clothing integrated with various functions is solidifying its position as the core of next-generation Information and Communications Technology(ICT). With this global trend, the smart textiles, textiles embedded with electronic devices that are capable of performing various functions, have been attracting a lot of attention. Therefore, various research activities on the smart textiles are in progress, and the global market outlook for the smart textiles is also showing rapid growth. Among the various smart textile technologies, the textile/fiber-based wearable display has been attracting more attention because it is an essential element for wearers to intuitively control the functions integrated in the smart textiles. This paper provides insightful information and the technological elements of organic light emitting diodes(OLEDs) display, which have been evaluated as the most ideal device for luminescent clothing. Since, OLEDs have many advantages such as light weight, extremely thin thickness and great flexibility, the textile/fiber-based wearable OLEDs can be worn without any inconvenience. In addition, by introducing previous studies on the textile/fiber-based OLED displays, we intend to consider the commercial potential of the textile/fiber-based smart luminescent clothing using the OLED technologies.

On-site water level measurement method based on wavelength division multiplexing for harsh environments in nuclear power plants

  • Lee, Hoon-Keun;Choo, Jaeyul;Shin, Gangsig;Kim, Sung-Man
    • Nuclear Engineering and Technology
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    • 제52권12호
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    • pp.2847-2851
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    • 2020
  • A simple water level measurement method based on wavelength division multiplexing (WDM) is proposed and demonstrated. The measurement principle is based on the change of Fresnel reflection occurring at the end facet of the optical fiber tip (OFT). To increase the spatial resolution of water level sensing, a broadband light source (BLS) and an arrayed waveguide grating (AWG) are employed. The OFTs are multiplexed with the dedicated wavelength channels of AWG. By measuring all of the reflection powers reflected at the OFTs with a proposed on-site reflectometer, the water level can be monitored continuously for a fast emergency response. Moreover, it can be implemented easily with the commercially available optical components and devices with the simple configuration.

전광파이버형 광파이버 자이로 (All-Fiber Optic Gyroscope)

  • 김인수;김요희
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 E
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    • pp.1840-1842
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    • 1998
  • Gyroscope is a very important core sensor, as a rotation sensor in inertial space, in inertial guidance and navigation system on aeronautics, plane, vessel and so on for civilian and millitary applications. Mechnical gyroscopes, adopting a principle of spinning a top, have been used in many application system. These mechnical gyroscopes need high power consumption, long warming time and complicated peripheral devices. But fiber-optic gyroscopes, based on the Sagnac effect, have novel advantages as small volume. simple scheme, low power consumption and high reliability. So we have developed a Intermediate grade All-fiber Optic Gyroscope, which has open-loop and minimum reciprocal configuration scheme. We have designed feedback circuits for stability of amplitude and phase using four lock-in amplifier(LIA) circuits and also used for noise limitation. This paper describes the scheme of optical part and electronic part and also test results of this all-fiber optic gyroscope. The performance have been achieved as long-term bias drift of $9.54^{\circ}/h$, random walk of $0.0317^{\circ}/\sqrt{h}$ and dynamic range of ${\pm}150\;deg/s$.

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Polyaniline을 이용한 CNT fiber 유연 전극 기반의 비효소적 글루코스 검출 (Enzyme-Free Glucose Sensing with Polyaniline-Decorated Flexible CNT Fiber Electrode)

  • 송민정
    • Korean Chemical Engineering Research
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    • 제60권1호
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    • pp.1-6
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    • 2022
  • 최근 웨어러블 디바이스에 대한 수요가 증가하면서 유연 전극 소재 개발에 대한 다양한 연구들이 진행되고 있다. 특히, 헬스케어용 웨어러블 센서들은 체온이나 심장 박동, 혈당, 혈중 산소 농도 등 신체 정보들의 실시간·지속적인 모니터링과 정확한 진단, 검출이 가능해야 하기 때문에 고성능 유연 전극 소재의 개발이 무엇보다 중요하다. 본 연구에서는 탄소나노튜브 섬유(carbon nanotube fiber; CNT fiber) 기반의 유연 전극 소재의 성능을 개선시키기 위해 CNT fiber 위에 전기화학적 중합(electrochemical polymerization) 공정을 통해 polyaniline (PANI) layer를 합성하고, 이에 대한 전기화학적 특성 분석과 비효소적 글루코스(glucose) 검출 특성을 확인하였다. 제작된 PANI/CNT fiber 전극의 표면 분석은 주사전자 현미경(SEM)을 이용하여 진행되었으며, 전극의 전기화학적 특성 및 글루코스에 대한 센싱 성능은 시간대전류법(CA)과 순환전압 전류법(CV), 전기화학 임피던스법(EIS)을 이용하여 분석되었다. PANI/CNT fiber 전극의 전기화학적 특성은 bare CNT fiber 전극에 비해 작은 electron transfer resistance와 낮은 peak separation potential, 증가된 전극 면적을 나타내며, 이런 향상된 특성들 덕분에 글루코스 검출에 대한 센싱 성능이 개선되었다. 따라서, 본 연구를 기반으로 다양한 나노구조체를 도입하고 접목을 통해 고성능 CNT fiber 기반의 유연 전극 소재 개발이 가능할 것으로 기대된다.

측면 연마 광섬유를 이용한 용액의 광학 특성 측정 (Measurement of Optical Properties of a Liquid Based on a Side-polished Optical Fiber)

  • 이현진;김광택
    • 한국전기전자재료학회논문지
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    • 제27권3호
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    • pp.195-198
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    • 2014
  • In this paper, a measurement method to obtain the optical properties of a liquid base on a side-polished single mode fiber was proposed and demonstrated. The device showed periodic resonance coupling against wavelengths. The refractive index and dispersion characteristics of a liquid were calculated by use of the spacings of periodic resonance wavelengths of the device. The thermo-optic coefficient of the liquid was obtained by monitering the shift of resonance wavelengths of the devices with change of environmental temperature.

High Performance Wearable/Flexible Energy Storage Devices Based on Ultrathin $Ni(OH)_2$ Coated ZnO Nanowires

  • Shakir, Imran;Park, Jong-Jin;Kang, Dae-Joon
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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    • pp.597-597
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    • 2012
  • A simple solution-based method is developed to deposit crystalline ultrathin (2 nm) nickel hydroxide on vertically grown ZnO nanowires to achieve high specific capacitance and long-term life for flexible and wearable energy storage devices. Ultrathin crystalline $Ni(OH)_2$ enables fast and reversible redox reaction to improve the specific capacitance by utilizing maximum number of active sites for the redox reaction while vertically grown ZnO nanowires on wearable textile fiber effectively transport electrolytes and shorten the ion diffusion path. Under the highly flexible state $Ni(OH)_2$ coated ZnO nanowires electrode shows a high specific capacitance of 2150 F/g (based on pristine $Ni(OH)_2$ in 1 M LiOH aqueous solution with negligible decrease in specific capacitance after 1000 cycles. The synthesized energy-storage electrodes are easy-to-assemble which can provide unprecedented design ingenuity for a variety of wearable and flexible electronic devices.

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Fiber optic shape sensor system for a morphing wing trailing edge

  • Ciminello, Monica;Ameduri, Salvatore;Concilio, Antonio;Dimino, Ignazio;Bettini, Paolo
    • Smart Structures and Systems
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    • 제20권4호
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    • pp.441-450
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    • 2017
  • The objective of this work is to present a conceptual design and the modelling of a distributed sensor system based on fiber optic devices (Fiber Bragg Grating, FBG), aimed at measuring span-wise and chord-wise variations of an adaptive (morphing) trailing edge. The network is made of two different integrated solutions for revealing deformations of the reference morphing structure. Strains are confined to typical values along the span (length) but they are expected to overcome standard ranges along the chord (width), up to almost 10%. In this case, suitable architectures may introduce proper modulations to keep the measured deformation low while preserving the information content. In the current paper, the designed monitoring system combines the use of a span-wise fiber reinforced patch with a chord-wise sliding beam. The two elements make up a closed grid, allowing the reconstruction of the complete deformed shape under the acceptable assumption that the transformation refers to regular geometry variations. Herein, the design logic and some integration issues are reported. Preliminary experimental test results are finally presented.