• 제목/요약/키워드: Infrared laser

검색결과 329건 처리시간 0.03초

APPLICATION OF A MULTI-WAVELENGTH NIR DIODE LASER ARRAY FOR NON-DESTRUCTIVE FOOD ANALYSIS

  • Tauscher, Bernhard;Butz, Peter;Lindauer, Ralf
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 한국근적외분광분석학회 2001년도 NIR-2001
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    • pp.3123-3123
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    • 2001
  • Near infrared (NIR) spectroscopy has become a widely used method in food and beverage analysis because of its speed, accuracy and the simplicity of sample preparation. One of the basic requirements of NIR instruments is a wide dynamic range if weak, or small, absorption changes or concentrations are to be measured. Thus the instrument must be sufficiently luminous, and efficient, to enable measurements to be made in a reasonably short time, as for some applications (e.g. sorting) short response times are essential. Diode lasers function the same way as lasers but linewidths are not as narrow as typical lasers. In this work an array of seven laser diodes (in the range of 750-1100 nm) with energy outputs of around hundred milliwatts each were combined with a fast diode array spectrometer (400-1100 nm, 1024 pixels, integration time from 3 ms) as detector. Measurements in transmission mode were performed in solutions of sugars in aqueous solutions and in deuteriumoxide. The feasibility of non-destructive measurements in transmission mode was investigated for different fruits and vegetables.

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Optical and Thermal Characteristic Studies of Cartilage by Laser Irradiation (레이저에 의한 연골의 광학적 열적 특성변화 연구)

  • Lee, Yeon-Ui;Youn, Jong-In
    • Journal of Biomedical Engineering Research
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    • 제32권3호
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    • pp.270-277
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    • 2011
  • Laser cartilage reshaping(LCR) is a promising method for reshaping cartilage by using laser irradiation to maintain permanently modifies its shape. However this method has not been fully understood due to the limited scientific researches. The purpose of this study is to analyze optical and thermal characteristics of cartilage during laser irradiation. After analyzing Monte Carlo simulation for the comparison of laser fluence distributions with different laser wavelengths the characterization of the spectral changes during Nd:YAG laser(${\lambda}$ = 1444 nm) irradiation was investigated in the ranges of 900-1700 nm with double integrating spheres. The surface temperature distribution changes during laser irradiation were investigated with an infrared camera. The quantitative measurements of optical and thermal characteristics in cartilage after laser irradiation were correlated with the transition of water flux(from bound to free water) and this study may be useful for better understanding of biophysical transformation phenomena in cartilage after laser heating.

Observation of Elusive CF2Cl…Cl in Matrix Infrared Spectra and Density Functional Calculations

  • Cho, Han-Gook
    • Bulletin of the Korean Chemical Society
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    • 제34권11호
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    • pp.3274-3278
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    • 2013
  • $CF_2Cl{\cdots}Cl$, an elusive photo-isomer of $CF_2Cl_2$, has been observed in matrix IR spectra from the precursors exposed to radiation from laser ablation of transition-metals. Other plausible products, $CFCl_2{\cdots}F$ and $FClC{\cdots}F-Cl$ are not detected due to their considerably higher energies. Parallel to its previously reported analogues, the C-X bonds are considerably stronger than those of the reactant, and particularly the Cl atom that is weakly bound to the residual Cl atom forms an unusually strong carbon-halogen bond. NBO analysis reveals that the C-Cl bond is a true double bond, and the weak $Cl{\cdots}Cl$ bond is largely ionic, $F_2C=Cl^{\delta+}{\cdots}Cl^{\delta-}$. IRC computation reproduces smooth inter-conversion between the reactant and product, and the transition state is energetically close to the product, consistent with its prompt disappearance in the early stage of photolysis.

Target Tracking System for an Intelligent Wheelchair Using Infrared Range-finder and CCD Camera (적외선 레인지파인더와 CCD 카메라를 이용한 지능 휠체어용 표적 추적 시스템)

  • Ha Yun-Su;Han Dong-Hee
    • Journal of Advanced Marine Engineering and Technology
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    • 제29권5호
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    • pp.560-570
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    • 2005
  • In this paper, we discuss the tracking system for a wheelchair which can follow the path of a human target such as a nurse in hospital. The problem of human tracking is that it requires recognition of feature as well as the tracking of human positions. For this purpose the use of a high cost visual sensor such as laser finder or streo camera makes the tracking a high cost additional expense. This paper proposes the tracking system uses a low cost infrared range-finder and CCD camera, The Infrared range-finder and CCD camera can create a target candidate through each target recognition algorithm. and this information is fused in order to reduce the uncertainties of a target decision and correct the positional error of the human. The effectiveness of the proposed system is verified through experiments.

A study on the characteristic analysis and correction of non-linear bias error of an infrared range finder sensor for a mobile robot (이동로봇용 적외선 레인지 파인더센서의 특성분석 및 비선형 편향 오차 보정에 관한 연구)

  • 하윤수;김헌희
    • Journal of Advanced Marine Engineering and Technology
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    • 제27권5호
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    • pp.641-647
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    • 2003
  • The use of infrared range-finder sensor as the environment recognition system for mobile robot have the advantage of low sensing cost compared with the use of other vision sensor such as laser finder CCD camera. However, it is not easy to find the previous works on the use of infrared range-finder sensor for a mobile robot because of the non-linear characteristic of that. This paper describes the error due to non-linearity of a sensor and the correction of it using neural network. The neural network consists of multi-layer perception and Levenberg-Marquardt algorithm is applied to learning it. The effectiveness of the proposed algorithm is verified from experiment.