• Title/Summary/Keyword: Near-infrared Light

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Monitoring of Environmental Arsenic by Cultures of the Photosynthetic Bacterial Sensor Illuminated with a Near-Infrared Light Emitting Diode Array

  • Maeda, Isamu;Sakurai, Hirokazu;Yoshida, Kazuyuki;Siddiki, Mohammad Shohel Rana;Shimizu, Tokuo;Fukami, Motohiro;Ueda, Shunsaku
    • Journal of Microbiology and Biotechnology
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    • v.21 no.12
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    • pp.1306-1311
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    • 2011
  • Recombinant Rhodopseudomonas palustris, harboring the carotenoid-metabolizing gene crtI (CrtIBS), and whose color changes from greenish yellow to red in response to inorganic As(III), was cultured in transparent microplate wells illuminated with a light emitting diode (LED) array. The cells were seen to grow better under near-infrared light, when compared with cells illuminated with blue or green LEDs. The absorbance ratio of 525 to 425 nm after cultivation for 24 h, which reflects red carotenoid accumulation, increased with an increase in As(III) concentrations. The detection limit of cultures illuminated with near-infrared LED was 5 ${\mu}g$/l, which was equivalent to that of cultures in test tubes illuminated with an incandescent lamp. A near-infrared LED array, in combination with a microplate, enabled the simultaneous handling of multiple cultures, including CrtIBS and a control strain, for normalization by the illumination of those with equal photon flux densities. Thus, the introduction of a near-infrared LED array to the assay is advantageous for the monitoring of arsenic in natural water samples that may contain a number of unknown factors and, therefore, need normalization of the reporter event.

Cloud-Type Classification by Two-Layered Fuzzy Logic

  • Kim, Kwang Baek
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.13 no.1
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    • pp.67-72
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    • 2013
  • Cloud detection and analysis from satellite images has been a topic of research in many atmospheric and environmental studies; however, it still is a challenging task for many reasons. In this paper, we propose a new method for cloud-type classification using fuzzy logic. Knowing that visible-light images of clouds contain thickness related information, while infrared images haves height-related information, we propose a two-layered fuzzy logic based on the input source to provide us with a relatively clear-cut threshold in classification. Traditional noise-removal methods that use reflection/release characteristics of infrared images often produce false positive cloud areas, such as fog thereby it negatively affecting the classification accuracy. In this study, we used the color information from source images to extract the region of interest while avoiding false positives. The structure of fuzzy inference was also changed, because we utilized three types of source images: visible-light, infrared, and near-infrared images. When a cloud appears in both the visible-light image and the infrared image, the fuzzy membership function has a different form. Therefore we designed two sets of fuzzy inference rules and related classification rules. In our experiment, the proposed method was verified to be efficient and more accurate than the previous fuzzy logic attempt that used infrared image features.

The Color Matching Algorithm in Near Infrared Range for Military Camouflage (IR영역에서의 위장염색을 위한 칼라 매칭 알고리즘 연구)

  • Song Kyung-Hun;Yuk Jong-Il;Ha Hun-Seung;Lee Tae-Sang;You Young-Eun;Lee Si-Woo
    • Textile Coloration and Finishing
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    • v.17 no.4 s.83
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    • pp.7-14
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    • 2005
  • The purpose of this study was to develop the color matching program with the excellent camouflage capacity in the near infrared range($\~$1100nm) including the visible light range for cotton fabrics. It was measured IR spectral reflectance in the range of $380\~1,100nm$ after dyed with vat dyes, and we made database for reflectance with various concentration on vat dyes which have a low reflectance value in the infrared range. The color matching algorithm that could be simulated in both the human visible light and the near infrared range was constructed by numerical analysis method using the database. In this study we also developed the dyeing conditions and dyeing process through the continuous-dyeing experiment with the vat dyes for cotton fabrics.

Image Dehazing Algorithm Using Near-infrared Image Characteristics (근적외선 영상의 특성을 활용한 안개 제거 알고리즘)

  • Yu, Jae Taeg;Ra, Sung Woong;Lee, Sungmin;Jung, Seung-Won
    • Journal of the Institute of Electronics and Information Engineers
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    • v.52 no.11
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    • pp.115-123
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    • 2015
  • The infrared light is known to be less dependent on background light compared to the visible light, and thus many applications such as remote sensing and image surveillance use the infrared image. Similar to color images, infrared images can also be degraded by hazy weather condition, and consequently the performance of the infrared image-based applications can decrease. Nevertheless, infrared image dehazing has not received significant interest. In this paper, we analyze the characteristic of infrared images, especially near-infrared (NIR) images, and present an NIR dehazing algorithm using the analyzed characteristics. In particular, a machine learning framework is adopted to obtain an accurate transmission map and several post-processing methods are used for further refinement. Experimental results show that the proposed NIR dehazing algorithm outperforms the conventional color image dehazing method for NIR image dehazing.

Study on characteristics of thin films for reflection of near infrared light (근적외선 반사 박막 특성 연구)

  • Chung, Youn-Gil;Park, Hyun-Sik
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.6
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    • pp.4121-4124
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    • 2015
  • Near infrared blocking function in energy saving window glass is required. The design, deposition and characteristics of optical thin films for reflection of near-infrared light were studied. The optical thin film is designed as laminated film structure with low refractive index film and high index film. Deposition experiments of $SiO_2$ and $TiO_2$ thin films with designed structure using the RF sputtering method were carried out. The characteristics of the thin film with deposition conditions were analyzed. High-refractive-index thin film of $TiO_2$/low refractive-index thin film of $SiO_2$ and high-refractive-index thin film of $TiO_2$ structure for reflection of near-infrared light was designed to be simulated. Results of simulation showed reflectance of 30% or more in the range from 930nm to 1682nm. Triple layer thin films fabricated with simulated results showed wavelength bands from 930nm to 1525nm for the reflectance of 33% or more.

Assessment and Comparison of Three Dimensional Exoscopes for Near-Infrared Fluorescence-Guided Surgery Using Second-Window Indocyanine-Green

  • Cho, Steve S.;Teng, Clare W.;Ravin, Emma De;Singh, Yash B.;Lee, John Y.K.
    • Journal of Korean Neurosurgical Society
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    • v.65 no.4
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    • pp.572-581
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    • 2022
  • Objective : Compared to microscopes, exoscopes have advantages in field-depth, ergonomics, and educational value. Exoscopes are especially well-poised for adaptation into fluorescence-guided surgery (FGS) due to their excitation source, light path, and image processing capabilities. We evaluated the feasibility of near-infrared FGS using a 3-dimensional (3D), 4 K exoscope with near-infrared fluorescence imaging capability. We then compared it to the most sensitive, commercially-available near-infrared exoscope system (3D and 960 p). In-vitro and intraoperative comparisons were performed. Methods : Serial dilutions of indocyanine-green (1-2000 ㎍/mL) were imaged with the 3D, 4 K Olympus Orbeye (system 1) and the 3D, 960 p VisionSense Iridium (system 2). Near-infrared sensitivity was calculated using signal-to-background ratios (SBRs). In addition, three patients with brain tumors were administered indocyanine-green and imaged with system 1, with two also imaged with system 2 for comparison. Results : Systems 1 and 2 detected near-infrared fluorescence from indocyanine green concentrations of >250 ㎍/L and >31.3 ㎍/L, respectively. Intraoperatively, system 1 visualized strong near-infrared fluorescence from two, strongly gadolinium-enhancing meningiomas (SBR=2.4, 1.7). The high-resolution, bright images were sufficient for the surgeon to appreciate the underlying anatomy in the near-infrared mode. However, system 1 was not able to visualize fluorescence from a weakly-enhancing intraparenchymal metastasis. In contrast, system 2 successfully visualized both the meningioma and the metastasis but lacked high resolution stereopsis. Conclusion : Three-dimensional exoscope systems provide an alternative visualization platform for both standard microsurgery and near-infrared fluorescent guided surgery. However, when tumor fluorescence is weak (i.e., low fluorophore uptake, deep tumors), highly sensitive near-infrared visualization systems may be required.

The Change of Blood Flow Velocity of Radial Artery after Linear Polarized Infrared Light Radiation near the Stellate Ganglion: Comparing with the Stellate Ganglion Block (성상신경절 부위의 직선편광 근적외선 조사 후 요골동맥에서의 혈류속도의 변화: 성상신경절 차단술과의 비교)

  • Han, Soung-Moon;Lee, Sang-Chul
    • The Korean Journal of Pain
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    • v.14 no.1
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    • pp.37-40
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    • 2001
  • Background: It had been reported by authors that linear polarized infrared light radiation (Superizer: SL) near the stellate ganglion had a similar effect on the change of skin temperature of hand compared with the stellate ganglion block (SGB). We hypothesized that this was due to dilatation of vessels and an increased blood flow. The aim of this study was to measure the velocity of blood flow in peripheral vessels after linear polarized infrared light radiation near the stellate ganglion and to compare the effect of SL with that of SGB using local anesthetics. Methods: Forty patients whose clinical criteria were matched for the symptoms of SGB were selected for study. We radiated the stellate ganglion by linear polarized infrared light radiation and measured the blood flow of radial artery using Ultrasound Doppler blood flow meter before and after 10, 20 and 30 minutes post-radiation. After 3 days, SGB was performed using 8 ml of 1% mepivacaine to the same patient, and the radial artery blood flow was measured in the same manner. Results: The blood flow velocity was increased by 40% and 27% at 10 min and 20 min after SL and by 42% and 41% at 10 min and 20 min after SGB. However, there was no statistically significant difference in blood flow velocity between SGL and SGB. Conclusions: We could conclude that linear polarized radiation is a clinically simple and useful noninvasive therapeutic tool in clinical area.

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THEORY AND PRINCIPLES OF NEAR INFRARED SPECTROSCOPY

  • Barton, Franklin E.
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1012-1012
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    • 2001
  • The elegant early experiments of Herschel demonstrated that there is light after the visible spectrum in a region we call the near infrared (NIR). This was followed by the work which showed that the spectrum went further into what we call the mid infrared (MIR). The MIR has been used for many years as a qualitative and quantitative region to measure constituent values. The MIR region contains the fundamental vibrations which can be theoretically calculated from symmetry rules and harmonic oscillator equations. The NIR is not as straight forward because the region from 400-2500 nm does not contain any of the fundamental vibrations only combination bands and overtones. Over the past fifty years efforts to understand the NIR have largely been ignored while the quantitative aspects of the region have been utilized. This presentation will focus on the efforts to define terms for NIR, examine the calculation of combination bands and overtones and ways to interpret the spectra. The interpretation of the NIR has been aided greatly in recent years by the use of two dimensional spectroscopy which allows the correlation of bands in one spectral region with that of the NIR.

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APPLICATION OF TIME-OF-FLIGHT NEAR INFRARED SPECTROSCOPY TO WOOD

  • Tsuchikawa, Satoru;Tsutsumi, Shigeaki
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1182-1182
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    • 2001
  • In this study, the newly constructed optical measurement system, which was mainly composed of a parametric tunable laser and a near infrared photoelectric multiplier, was introduced to clarify the optical characteristics of wood as discontinuous body with anisotropic cellular structure from the viewpoint of the time-of-flight near infrared spectroscopy (TOF-NIRS). The combined effects of the cellular structure of wood sample, the wavelength of the laser beam λ, and the detection position of transmitted light on the time resolved profiles were investigated in detail. The variation of the attenuance of peak maxima At, the time delay of peak maxima Δt and the variation of full width at half maximum Δw were strongly dependent on the feature of cellular structure of a sample and the wavelength of the laser beam. The substantial optical path length became about 30 to 35 times as long as sample thickness except the absorption band of water. Δt ${\times}$ Δw representing the light scattering condition increased exponentially with the sample thickness or the distance between the irradiation point and the end of sample. Around the λ=900-950 nm, there may be considerable light scattering in the lumen of tracheid, which is multiple specular reflection and easy to propagate along the length of wood fiber. Such tendency was remarkable for soft wood with the aggregate of thin layers of cell walls. When we apply TOF-NIRS to the cellular structural materials like wood, it is very important to give attention to the difference in the light scattering within cell wall and the multiple specular-like reflections between cell walls. We tried to express the characteristics of the time resolved profile on the basis of the optical parameters for light propagation determined by the previous studies, which were absorption coefficient K and scattering coefficient S from Kubelka-Munk theory and n from nth power cosine model of radiant intensity. The wavelength dependency of the product of K/S and n, which expressed the light-absorbing and -scattering condition and the degree of anisotropy, respectively, was similar to that of the time delay of peak maxima Δt. The variation of the time resolved profile is governed by the combination of these parameters. So, we can easily find the set of parameters for light propagation synthetically from Δt.

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