• Title/Summary/Keyword: Fiber Selection

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Ultrashort Optical Pulse Generation at 10 GHz by Pulse Compression of Actively Mode-Locked Fiber Laser Output (능동 모드잠금 광섬유 레이저 출력의 펄스 압축에 의한 10 GHz 극초단 광 펄스 발생)

  • Seo, Dong-Sun;Weiner, Andrew M.
    • Journal of IKEEE
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    • v.9 no.2 s.17
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    • pp.115-122
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    • 2005
  • We report 400 femto-second highly stable, nearly transform-limited, pulse generation at 10 GHz in $1540{\sim}1550$ nm wavelength region by adiabatic soliton pulse compression of an actively mode-locked fiber ring laser output. Without using any supermode selection device, supermode beating noise has been suppressed below -123 dB/Hz, resulting less than 100 femto-second timing jitters at the noise band of $1\;kHz{\sim}100\;MHz$.

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Multipoint Process Monitoring System Based on a Near Infrared Ray(NIR) Acousto-Optic Tunable Filter(AOTF)

  • You, Jang-Woo;Kim, Daesuk;Kim, Soohyun;Kong, Hong-Jin;Lee, Yunwoo;Kwak, Yoon-Keun
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.105.4-105
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    • 2001
  • This paper describes a newly designed multipoint process monitoring system based on a NIR acousto-optic tunable filter. The NIR multipoint process monitoring system consists of a NIR AOTF device for wavelength selection, an InGaAs array sensor, and a specially designed iin-line type of optical fiber probe. Unlike a FTS(Fourier Transform Spectrometry) or grating based monitoring system, an AOTF has no moving parts, and it can be rapidly tuned to any wavelength in its operating range within microseconds. Thus, the AOTF is advantageous in terms of faster spectral imaging capability and rigidity required for industrial monitoring environment. In the current feasibility evaluation, an enhanced optical fiber probe with 3 monitoring points was used. However, ...

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Study on the Improvement of Indirect Intra-Oral Dental Digital X-ray Image Sensor with Optical Coupling

  • Whang, Joo-Ho;Chung, Jin-Bum;Kim, Tae-Woo
    • Nuclear Engineering and Technology
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    • v.33 no.5
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    • pp.514-525
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    • 2001
  • Optimum characteristics of digital X-ray sensor components were analyzed to develop intra- oral dental digital X-ray image sensor using indirect method. Parametric analysis was carried out to optimize the phosphor thickness and the fiber optic plate (FOP) coupling to charge coupled device (CCD). X-ray absorption and light diffusion in the phosphor layer were analyzed by the Monte Carlo method. Real time X-ray image was obtained with prototype X- ray image sensor using general CCD camera with 1∼10 Ip/mm resolution. It has been previously shown that large resolution degradation in X-ray images was caused by miss alignment of FOP to CCD and optical adhesive selection. In this study, we reported that X-ray image quality was greatly improved by using optimized characteristics of alignment device and phosphor thickness.

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New Technologies for Sow Nutrition and Management - Review -

  • Sohn, K.S.;Maxwell, C.V.
    • Asian-Australasian Journal of Animal Sciences
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    • v.12 no.6
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    • pp.956-965
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    • 1999
  • Genetic selection and sophisticated management technology have produced modern sows which excel in litter size and milk production. Recent research has identified nutritional innovations which may enhance productivity of the high producing sow. Selected research in three areas which have the potential to enhance reproductive performance are summarized in this report. First, preliminary evidence indicates that organic chromium may enhance litter size and conception rate. Secondly, high producing sows, particularly primiparous sows, required higher protein/lysine in late gestation and or lactation to optimize weaning weight and subsequent litter size. Valine and isoleucine, but not leucine, have been shown to enhance milk production. Phased feeding programs with diet cost partitioned toward gilts and away form parity 3 to 8 sows have been suggested as a means of improving reproductive performance in young sows. Lastly, recent research with sufficient sow numbers to document the effect of dietary fiber on reproductive performance has shown that sows fed fiber farrowed and weaned more pigs.

Guidance Scheme for Air-to-Ground Anti-tank Missiles Under Physical Constraints (물리적 구속조건을 고려한 공대지 대전차 유도탄의 유도기법 연구)

  • Park, Bong-Gyun;Um, Tae-Yoon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.68 no.1
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    • pp.145-152
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    • 2019
  • A composite guidance scheme is proposed for air-to-ground anti-tank missiles launched from an airborne platform. Long-range anti-tank missiles usually use a fiber optic line (FOL) for the datalink between an operator and the missile to obtain real-time target information and to command the missile. Also, impact angle control is used to maximize the warhead effectiveness, but it should be carefully implemented due to interference between the launch platform and the FOL. Thus, the proposed guidance scheme takes into account both impact angle and FOL constraints. Under system lag and acceleration limits, a selection method of guidance gains and calculation logic of the maximum achievable impact angle are proposed for a guideline of practical implementation. The performance of the proposed guidance scheme is investigated by nonlinear simulations with various engagement conditions.

Study on the Optimal Mix Proportions of Lightweight Foam Concrete for Substitution of ALC (ALC 대체를 위한 선발포 경량기포콘크리트의 최적배합 선정 연구)

  • Choi, Sun-Mi;Kim, Beom-Soo;Kim, Jin-Man
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2023.05a
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    • pp.199-200
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    • 2023
  • This paper presents a study on the selection of optimal mix proportions for producing lightweight pre-foam concrete as a substitute for Autoclaved Lightweight Concrete (ALC) without the accelerated curing. The study was conducted using a rapid hardening binder made from by-products of the steel industry as the primary raw material. The experimental results established the optimal mix proportions, which included retarder content, water/binder ratio, foam content, and fiber inclusion amount, for the production of lightweight foam concrete. The optimal mix proportion was determined to have a retarder content at the minimum amount required to secure the working time, W/B of 35%, a foam content limited to 65% or less, and a fiber inclusion amount of 0.05% or less.

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The development of near infrared calibrations for assessing grass herbage quality

  • Sharma, Hss;Mellon, R.;Johnson, D.;Fletcher, H.
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1611-1611
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    • 2001
  • The main selection parameters used by forage grass (rye and Italian rye grass) breeders are dry-matter yield, seasonal growth, persistency, disease resistance, heading date, and heading. These characteristics can all be identified usually in the segregating F2 population, however characteristics such as soluble carbohydrate level, protein, lipid and digestibility cannot be identified. The emphasis of this work is to introduce a quantitative selection process for characterization of herbage quality e.g. protein, water-soluble carbohydrates, fiber fractions, dry matter digestibility. NIRS calibrations are currently being developed for identifying grass genotypes to assist the selection process, thereby allowing the opportunity to actively breed improved herbage quality. The changes in fibre fractions, associated components and digestibility of a number of grass clones at different growth stages are being assessed changes taking place during a growing season. This will provide a database of the major changes taking place during a growing season. Attempts to classify quality differences between genotypes will be carried out using multivariate analysis of the spectral data. I addition changes associated with maturity of grass will be considered in order to develop robust calibrations.

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The process optimization for development of super deep black fiber (고심색용 폴리에스테르 섬유제품의 개발을 위한 공정최적화 연구)

  • Kim, Tae-Kyeong;Jeon, Jun-Hyung;Kim, Eun-Cheol
    • Textile Coloration and Finishing
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    • v.19 no.1 s.92
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    • pp.53-60
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    • 2007
  • In order to optimize the process for development of super deep black fiber, the silica-containing polyester fabric, SN2000, was investigated in terms of mass reduction process by sodium hydroxide, selection of high color strength dyes, and resin treatment. As the results, the mass reduction condition which used 15g/L of sodium hydroxide at $120^{\circ}C$ was determined and Dianix Deep Black Plus was selected for the best deep coloration at around 5% owf. Contrary to the prevailed understanding that the additional use of chromatic dyes would enhance the deep coloration, four kinds of chromatic dyes such as yellow, red, blue, and green dyes did not make great effect on the deep coloration. To increase the effect, the commercial resin that has low refractive index was used additionally and the resin made it possible to lower the lightness of the fabrics down to 8.7 which was generally accepted for super highly deep black fabric.

An Analytical Study to Reduce Plastic Deformation in Intersection Pavements (교차로 포장 소성변형 저감을 위한 해석적 연구)

  • Choi, Jun-Seong;Lee, Kang-Hun;Kwon, Soo-Ahn;Jeong, Jin-Hoon
    • International Journal of Highway Engineering
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    • v.14 no.4
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    • pp.29-36
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    • 2012
  • PURPOSES : Plastic deformation is frequently made in intersection asphalt pavement at its early age due to deceleration and stoppage of vehicles. This study has been performed to provide a mechanistic basis for reasonable selection of paving method to minimize the plastic deformation at intersection. METHODS : Pavement layer, temperature, traffic volume of the intersections managed by the Daejeon Regional Construction and Management Administration were collected to calculate asphalt dynamic modulus with pavement depth by using a prediction equation suggested by the Korean pavement design guide. Performance of ordinary dense-graded asphalt pavement, polymer modified asphalt pavement, and fiber reinforced asphalt pavement was analyzed by finite element method and the results were used in a performance model to predict the plastic deformation. RESULTS : In aspect of performance, the three paving methods were usable under low traffic while the fiber reinforced asphalt pavement was the most suitable under heavy traffic. CONCLUSIONS : Reasonable paving method suitable for traffic characteristics in the intersection might be decided by considering economic feasibility.

Dynamic Analysis of Carbon-fiber-reinforced Plastic for Different Multi-layered Fabric Structure (적층 직물 구조에 따른 탄소강화플라스틱 소재 동적 특성 분석)

  • Kim, Chan-Jung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.26 no.4
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    • pp.375-382
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    • 2016
  • The mechanical property of a carbon-fiber-reinforced plastic (CFRP) is subjected to two elements, carbon fiber and polymer resin, in a first step and the selection of multi-layered structure is second one. Many combination of fabric layers, i.e. plainweave, twillweave, can be derived for candidates of test specimen used for a basic mechanical components so that a reliable identification of dynamic nature of possible multi-layered structures are essential during the development of CFRP based component system. In this paper, three kinds of multi-layered structure specimens were prepared and the dynamic characteristics of service specimens were conducted through classical modal test process with impact hammer. In addition, the design sensitivity analysis based on transmissibility function was applied for the measured response data so that the response sensitivity for each resonance frequency were compared for three CFRP test specimens. Finally, the evaluation of CFRP specimen over different multi-layered fabric structures are commented from the experimental consequences.