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Saptari, Vidi Alfandi 1975. "A spectroscopic system for near infrared glucose measurement." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/34131.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004.Includes bibliographical references.
Noninvasive blood glucose monitoring has been long envisioned to serve as an invaluable tool in the treatment of diabetes. The current invasive method makes it difficult for diabetic patients to perform frequent blood glucose measurements and maintain better control of their glucose levels, crucial in reducing the risks of complications. In this thesis, the use of the near infrared absorption spectroscopy is proposed and investigated. The light radiation is envisioned to be transmitted through thin tissue such as the webbing tissue between the thumb and the index finger. The main technical difficulties are identified to be those caused by complex interferences from other physiological variables and the weak near infrared glucose signals. Thus, the success of such a method hinges on adequately isolating the glucose signals from among the interferences as well as on obtaining high signal-to-noise-ratio spectra. The first objective of this thesis is to provide deeper quantitative understanding to the challenges described above. Such knowledge is key to developing clinically accurate and robust devices. This objective is accomplished through a series of systematic experimental and analytical investigations involving glucose measurements in various biological sample matrices.
(cont.) Analytical figures of merit such as "selectivity" and "limit of detection" are defined, and used to quantify the signal quality and to predict the robustness of the method. The second objective of this thesis is to design an optimum spectroscopic system for the near infrared glucose measurements in the methodically selected band region approximately between 2100 and 2300 nm. A unique, filter spectrometer is developed, which enables spectral signal-to-noise ratio improvement by an order of magnitude over the published data to-date employing top-grade commercial spectrometers, while significantly reducing the required signal acquisition time and hardware complexity. A spectral processing algorithm is developed, which enables the effective removal of spectral variations caused by changes or drifts in the instrument, environment and/or sample conditions, as well as those due to tissue scattering. The spectroscopic system is tested in experiments measuring glucose in synthetic biological solutions, human plasma samples and animal tissue samples. The thesis demonstrates that with a carefully designed system, noninvasive blood glucose measurements using the near infrared absorption spectroscopy is feasible.
by Vidi A. Saptari.
Ph.D.
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Karlsson, Jonas. "FPGA-Accelerated Dehazing by Visible and Near-infrared Image Fusion." Thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-28322.
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Fog and haze can have a dramatic impact on vision systems for land and sea vehicles. The impact of such conditions on infrared images is not as severe as for standard images. By fusing images from two cameras, one ordinary and one near-infrared camera, a complete dehazing system with colour preservation can be achieved. Applying several different algorithms to an image set and evaluating the results, the most suitable image fusion algoritm has been identified. Using an FPGA, a programmable integrated circuit, a crucial part of the algorithm has been implemented. It is capable of producing processed images 30 times faster than a laptop computer. This implementation lays the foundation of a real-time dehazing system and provides a significant part of the full solution. The results show that such a system can be accomplished with an FPGA.
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Velasco, Santoscoy María Martha de la Paz. "Hardware Control of a Near Infrared Fluorescence System : LabVIEW Programming and Evaluation." Thesis, Linköpings universitet, Biomedicinsk instrumentteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-129604.
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Indocyanine green (ICG) is a fluorescent dye used as an indicator in medicine and surgery. The maximum absorption wavelength of ICG is at 785 nm, while the maximum emission is around 820 nm. ICG is nontoxic and is rapidly excreted into the bile. Near infrared (NIR) fluorescence imaging or spectroscopy offer new settings for seeing the blood vessels, and also in oncological applications for finding sentinel lymph nodes (SLN) to investigate if the cancer has spread from the tumor to the lymphatic system. Given the aforementioned applications, the aim of this thesis was to develop a hardware control and a user interface in LabVIEW, and to evaluate the software, as well as the instrumentation using phantom measurements.The system consisted of a spectrometer, a laser (785 ± 5 nm) for ICG excitation, optical filters, and a fiber optical probe containing five fibers for light excitation, and one for light collection. The basic LabVIEW program designed for the spectrometer was used, and additional features were added such as the recording functions, online measurements, opening of the recorded files, saving comments, and a loop was created for the laser control. Optical phantoms were prepared to model tissue for measurements using 20 % intralipid that gave μs = 298 mm−¹ at the excitation wavelength. Agar 1% w/v and ICG were added to the phantoms using different fluorophore concentrations of 2 μg/mL, 10 μg/mL, 20 μg/mL, 25 μg/mL, and 40 μg/mL. The objective was to perform controlled measurements of steady state ICG fluorescence, the dynamics of photobleaching at different concentrations, and to find the optimal ICG concentration for obtaining the maximum fluorescence intensity. The light to excite ICG fluorescence emission was provided by using a laser output power of 10.4 mW and 200 ms of integration time in the spectrometer for optimal measurements.Measurements using the different gel phantoms showed maximum fluorescence ICG concentration to be between 16 μg/mL and 20 μg/mL. Moreover, photobleaching measurements showed to be ICG concentration-dependent, where those concentrations higher than the optimal one incrementally photobleached with time after being exposed to light. Higher concentrations presented an incremental photobleaching where they first reached a maximum peak and then the intensity decayed with time. Additionally, laser reflection at 782 nm showed that the reflection increased with time ranging from 130% – 460% as the ICG photobleached to 50% of its initial value. Normalization of ICG by the laser reflection signal was investigated to compensate for the intensity variations due to the measurement parameters including the distance from the light source to the target, and the angle of inclination of the probe. The lowest ICG concentration detectable by the system was 0.05 μg/mL.In conclusion, a LabVIEW hardware control and user interface was developed for controlling the spectrometer and the laser. Several measurements were made using the different phantoms, where the optimal concentration of ICG was estimated. It was shown that ICG fluorescence intensity and photobleaching behavior were dependent on the concentration. The results gave suggestions for future experimental design.NIRF
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Davis, R. Wesley. "A digital communication system using near infrared radiation transmitted through the atmosphere : presented." Scholarly Commons, 1993. https://scholarlycommons.pacific.edu/uop_etds/2253.
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A prototype communication system has been designed, built and tested. The system is a digital communication system that uses near infrared radiation transmitted through the atmosphere. The prototype system consists of two transceivers, each with associated electronics and power supplies. Each transceiver is capable of simultaneously transmitting and receiving light at a wavelength of 830 nm . The transmitter emits light in a 0.3 degree (full angle) cone through the atmosphere , while the receiver accepts light within its 0.33 degree field of view. For the purpose of alignment, each receiver also has an eyepiece and alignment reticle with a field-of-view of approximately 1.5 degrees.
The system is capable of transmitting and receiving digital data at a rate of up to 72 thousand bits per second (kbps) over a distance of 0 . 2 km on a clear day with an average transmitted power of less than 100 MW. Data is encoded for transmission using Pulse Position Modulation (PPM). The transmitting electronics include a pulse code modulation (PCM) voice digitizer, PPM modulator, and infrared emitter driver circuitry. The receiving circuitry includes a photodiode with bias supply and preamplifier, PPM automatic gain control, PPM demodulator, and PCM digital to analog converter
Finally, a model has been developed which describes system performance. The model may be used for investigating the performance of other similar systems which may need t o meet specific design criteria or restrictions.
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Kricke, Ralph [Verfasser]. "Lip Motion Analysis for a Person Authentication System under Near Infrared Illumination / Ralph Kricke." München : Verlag Dr. Hut, 2011. http://d-nb.info/1015608108/34.
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Akin, Ryan E. "Minimally invasive assessment of lymphatic pumping pressure using near infrared imaging." Thesis, Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/47536.
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Although the major functions of the lymphatic system are fairly well defined, its vasculature has yet to be well characterized in comparison to its blood vasculature counterpart. Recent advances in optical imaging techniques have allowed for more detailed and quantitative evaluations of lymph flow dynamics and mechanism. A rat tail is often used for investigations of lymph flow because of the simple geometry, superficial nature, and disease progression models of its collecting lymphatic vessels. In this study, a pressure cuff system was fabricated and coupled with an existing functional near infrared (NIR) imaging system to measure the overall pumping pressure of the lymphatic vessels of a rat tail. In addition to adapting the system for use on rodents, previous systems used for measuring lymphatic pumping pressure in humans were improved upon in several ways. The system defined here utilizes closed-loop feedback control of pressure application at smaller, more precise intervals. Using this device, a significant difference in lymphatic vessel pumping pressure was detected between a control case and a treatment case in which a vasoactive substance with a nitric oxide donor (GTNO ointment) was applied to the tail. Although it is known that nitric oxide plays a crucial physiologic role in propagation of flow through lymphatic vessels, this study has quantified its significant pharmacological reduction of pumping pressure for the first time.
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Hall, David Jonathan. "The development of a near infrared time resolved imaging system and the assessment of the methodology for breast imaging." Thesis, University College London (University of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243779.
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Harten, Paul Alexander. "Ultrafast phenomena in gallium arsenide/aluminum gallium arsenide multiple quantum well waveguide structures using a near infrared femtosecond laser system." Diss., The University of Arizona, 1992. http://hdl.handle.net/10150/185954.
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A near infrared hybridly mode-locked dye laser system consisting of a femtosecond oscillator and a high repetition rate dye amplifier was designed and built. This system was then applied to the study of room temperature below-bandgap femtosecond switching and coherent pulse propagation in GaAs/GaAlAs multiple quantum well waveguides. The noise properties of the oscillator output were studied using radio frequency spectrum analysis techniques. Two distinct modes of operation were identified: The first is characterized by the shortest pulse duration and its real-time autocorrelation signal appears more strongly modulated. The second mode of operation, which exhibits a slightly longer pulse duration and a smoother real-time autocorrelation signal, is obtained for a relative cavity length detuning of ΔL = -0.7 μm. Unexpectedly, the second mode features larger pulse duration fluctuations than the first mode and self-pulsing, while the pulse repetition timing and pulse energy fluctuations were found to be similar in both cases, making the first mode preferable for use in time-resolved experiments. Femtosecond all-optical switching under off-resonance room temperature excitation was demonstrated in a passive GaAs/AlGaAs multiple quantum well directional coupler for the first time. The required phase mismatch originates from an ultrafast refractive index change caused by the optical Stark effect. The main obstacle regarding practical device applications is its low transmission (less than 10%). The use of electrically pumped semiconductor waveguides that provide gain promises to remove this disadvantage. Below-resonance, coherent pulse breakup in a room temperature semiconductor waveguide was observed for the first time. Numerical simulations of the coupled semiconductor Maxwell-Bloch equations show that the light-matter interaction can induce enough chirp through self-phase modulation during propagation in order to violate the initial adiabatic following regime and cause pulse breakup. This coherent effect is distinctly different from self-induced transparency, because it does not involve Rabi-oscillations at the start of propagation, from temporal solitons, because it does not require group velocity dispersion, and from self-steepening. However, it should be ubiquitous under off-resonance pulse propagation with a pulse duration less than the polarization dephasing time.
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Dias, Diogo Da Silva. "Design of a low-cost wireless NIRS system withembedded Linux and a smartphone interface." Wright State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=wright1452960014.
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Bach, Mathias [Verfasser], and W. [Akademischer Betreuer] Heering. "Near Infrared Laser Sensor System for In-Line Detection of Conversion in UV-Cured Polymer Coatings / Mathias Bach ; Betreuer: W. Heering." Karlsruhe : KIT Scientific Publishing, 2012. http://d-nb.info/1184493200/34.
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Cassin, Steven. "Development of a near-infrared detection system for oxidative stress analysis of pregnant and non-pregnant mouse serum samples with parasite loading." Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=104596.
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This Thesis presents a quantitative tool that has been developed for the oxidative stress analysis of mouse serum using near-infrared (NIR) spectroscopy. We hypothesize that elevations in oxidative stress will cause changes in pre-selected NIR spectral regions. An optical detection system has been developed and optimized using bovine serum albumin. A total of 118 mouse serum samples were collected and NIR spectra were obtained. Sample collection was carried out in two stages. First, 70 mouse serum samples were collected followed by an additional 48 samples. A pre-selection of 5 hypothesis-driven wavelength regions (CH, SH, POH, ROH, and RNH2) were used in order to obtain spectral signatures for the serum samples. Spectra were analyzed using multi-linear regression (MLR) based optimizations were all possible variable combinations and ratios were computed. The Students' t-test for statistical significance was used to obtain the most parsimonious combination of variables.Pregnancy and infection status were classified using this approach. Mouse serum samples with doses of a murine gastrointestinal nematode were investigated. NIR spectral differences were observed for pregnant and non-pregnant serum samples with varying infection states in the 1600-2400 nm spectral window. Of the 5 pre-selected spectral regions, results indicate that 3 components (CH, SH, and POH) demonstrate the most pronounced changes in their relative means for non-pregnant mouse serum samples compared with non-infected and high infection states. The proposed 3-component model was used to differentiate between non-infected and high infected mouse serum samples with >95% confidence (sensitivity=82% and specificity=81%). Additionally, the proposed 3-component model was used to determine if a low infection state could be differentiated from both non-infected and high-infected samples. Significant differences with >95% confidence were obtained for mouse serum samples which were non-infected compared to those exhibiting high-infection states. These findings are significant in that they suggest an intermediate infection level may be both present and also quantified. The system was then also used to differentiate between infection states in 48 pregnant serum samples. The equation generated by the MLR was solved for the regions yielding the highest separations. Results showed improved separations with >95% confidence (sensitivity=86% and specificity=81%). The results confirm the hypothesis that CH, SH, and POH functional groups may be used as markers for the progression of infection. It should be highlighted that separations between infection states were achieved with >95% confidence independent of pregnancy status. This proposed research offers the basis for a rapid point-of-care method that could be used to differentiate samples with infection.Cette thèse présente un instrument quantitatif qui a été développé pour l'analyse de stress oxydatif de sérum en utilisant la spectroscopie proche infrarouge. Nous émettons une hypothèse que les élévations dans le stress oxydatif provoqueront des changements dans les régions spectrales pré-choisies. Un système de détection optique a été développé et a été optimisé avec de l'albumine. Un total de 118 échantillons a été recueilli et les spectres infrarouges-proche ont été mesurés. La collection d'échantillons s'est fait dans deux stages. D'abord, 70 sérums de souris ont été recueillis suivis par 48 échantillons supplémentaires. Une présélection de 5 régions spectrales (CH, SH, POH, ROH, et RNH2) a été utilisée pour obtenir des signatures spectrales pour les échantillons de sérum. Les données spectrales ont été analysées en utilisant la rétrogradation multilinéaire où toutes les combinaisons variables possibles et tous les ratios ont été calculés. La signification statistique a été utilisée pour obtenir la combinaison la plus parcimonieuse de variables.La grossesse et les états d'infection ont été classifiés en utilisant cette approche. Échantillons de sérum des souris avec des doses d'un nématode gastro-intestinal murin ont été étudiés. Les différences spectrales ont été observées pour les échantillons de sérum enceintes et non-enceintes avec les états d'infection variables dans la gamme spectrale 1600-2400 nm. Des 5 régions pré-choisies, les résultats indiquent que 3 composantes (CH, SH, et POH) démontrent les changements les plus prononcés dans leurs moyens relatifs pour les échantillons de sérum de souris enceintes avec les états d'infection non-infectés et de niveaux élevés. Le modèle de 3 composantes proposé a été utilisé pour faire la différence entre les échantillons de sérum de souris infectés, non-infectés et de niveaux d'infection élevés avec >95% confiance (sensibilité=82% et spécificité=81%). Le modèle de 3 composantes proposé a été utilisé pour déterminer si un état d'infection bas pourrait être différencié des échantillons non-infectés et de niveaux élevés. Les séparations significatives avec >95% confiance ont été obtenues pour l'échantillon de sérum de souris qui ont été non-infectés que ceux exposant l'infection haute. Ces conclusions sont significatives dans cela qu'ils suggèrent un niveau d'infection intermédiaire présent et qui pourrait être mesuré. Le plus intéressant, quand le modèle de 3 composant proposé a été appliqué aux 48 échantillons recueillis; les résultats ont montré des séparations améliorées avec >95% confiance (sensibilité=86% et spécificité=81%). Les résultats obtenus confirment l'hypothèse que CH, SH, et POH peuvent être utilisés comme les marqueurs pour la progression d'infection. Il devrait être accentué que les séparations entre les états d'infection ont été accomplies avec >95% confiance indépendante de statut de grossesse.Cette recherche proposée offre une signification dans le cycle ATP aussi bien que les ponts disulfures trouvés dans l'ADN.
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Cope, Mark. "The development of a near infrared spectroscopy system and its application for non-invasive monitoring of cerebral blood and tissue oxygenation in the newborn infants." Thesis, University College London (University of London), 1991. http://discovery.ucl.ac.uk/1317956/.
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This project had two main objectives. The first of these was to design and construct a spectroscopic instrument to monitor small changes in optical transmission across an infant's head at several near infrared wavelengths resulting from changes in the cerebral oxygenation status. The overall attenuation of light by brain tissue is very high and is dominated by the scattering properties of the tissue. Hence a major requirement of the instrument was the ability to measure spectral changes at very low light levels. Once the instrument was available, the second objective was to convert the measured changes in optical transmission into changes in the concentration of the naturally occurring chromophores oxyhaemoglobin, deoxyhaemoglobin and oxidised and reduced cytochrome c oxidase. An important aspect of the work was that the chromophore concentration measurements should be quantified in non-arbitrary units. Medical Physics is, by its nature, highly interdisciplinary and this is reflected in the introductory chapter which briefly covers the clinical problems, the medical science background and the technical aspects of monitoring the cerebral oxygenation status of newborn infants. The second and third chapters examine those constituents of brain tissue which absorb and scatter light and how the complication of multiple scattering can be dealt with in performing quantitative spectroscopy. The fourth and fifth chapters describe the technical details of the instrument design and construction from the initial step of setting its design specifications to the final testing of its performance. The sixth chapter examines the absorption characteristics of the main chromophores of interest namely oxyhaemoglobin, deoxyhaemoglobin and the cytochrome enzymes of the respiratory chain within the brain cells. A discussion on the interpretation of the redox state of the respiratory enzymes in terms of the metabolic state of the brain is also included. The final chapter describes the data analysis methods, the measurement of optical pathlengths in scattering media and introduces a non-linear modification to the Beer-Lambert law which improves the accuracy of the spectroscopic measurements in highly scattering media.
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Abdulkarim, Abrahim, and Outa Nima Nova Al. "Conceptualizing an automated sorting system for the recycling of plastic-floors." Thesis, Blekinge Tekniska Högskola, Institutionen för maskinteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-19713.
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Background Tarkett AB Ronneby (Sweden) is a flooring solutions company, recognized for the manufacturing and recycling of homogeneous plastic flooring. Tarkett AB recycles mainly installation spill and manufacturing defects. However, Tarkett AB is considering widening its recycling capabilities to include old and torn plastic floors which may contain impurities and banned substances or plastic floors of competing brands. To accomplish this, Tarkett is considering a completely new recycling line with an automated sorting process instead of the current manual process. Thus, Tarkett proposes a dissertation to conceptualize a new automated sorting system with added capacity and increased functionality. Purpose This work aims to investigate the current sorting process and introduce conceptual solutions for a new automated sorting process capable of identifying and separating plastic floors according to the manufacturer, type, condition, and external waste by using existing technology. Method The methods and tools used in this work are mainly based on a modified product development process. Starting with data collection of the current sorting process, performing a need-finding, and extracting requirements for an automated sorting process, investigating relevant technology, evaluating technology based on scientific literature and tests. The testing was conducted in collaboration with two companies. Near-infrared scanners were tested with Holger AB, while pattern recognition systems were tested with Vision-Geek. Finally, three concepts for the automated sorting process were developed and shown through flow charts and 2D-3D illustrations. Results The results of this work showed that it was possible to use near-infrared and pattern recognition for the separation of plastic floors. Besides, three conceptual solutions for an automated sorting process were generated and showcased with schematic graphs and 2D-3D illustrations. The concepts describe how the sorting process functions and what technology is used for each step of the process. Concept 1 and Concept 2 used both pattern recognition and spectroscopy methods. While Concept 3 only used spectroscopy methods. Moreover, spectroscopy methods were used to sort plastic floors by content while pattern recognition by appearance. Conclusions Recycling of torn and old plastic flooring can be beneficial for both the environment and the recycling industry. Yet, it presents some challenges relating to reliable, fast, and nondestructive identification for sorting and separation purposes. New and proven technology such as near-infrared hyperspectral imaging and pattern recognition can be used. However, high-quality pattern and spectrum libraries of multiple plastic floors have to be created for optimal and reliable reference models. Furthermore, pattern recognition and near-infrared methods need to be tested further at an industrial scale.Bakgrund Tarkett AB Ronneby (Sverige) är ett golvlösning företag, erkänt för tillverkning och återvinning av homogent plastgolv. Tarkett AB återvinner huvudsakligen installations spill och tillverkningsfel. Tarkett AB överväger dock att utvidga sina återvinnings förmågor till att omfatta gamla och sönderrivna plastgolv som kan innehålla föroreningar och förbjudna ämnen eller plastgolv från konkurrerande varumärken. För att åstadkomma detta överväger Tarkett en helt ny återvinnings linje med en automatiserad sorteringsprocess istället för den aktuella manuella processen. Således föreslår Tarkett ett examensarbete för att konceptualisera ett nytt automatiserat sorteringssystem med ökad kapacitet och ökad funktionalitet. Syfte Detta arbete syftar till att undersöka den nuvarande sorterings processen och introducera konceptuella lösningar för en ny automatiserad sorteringsprocess som kan identifiera och separera plastgolv efter tillverkare, typ, skick och externt avfall med befintlig teknik. Metod De metoder och verktyg som används i detta arbete är huvudsakligen baserade på en modifierad produktutvecklingsprocess. Vilket börja med datainsamling av den aktuella sorterings processen, hitta behov och extrahera krav för en automatiserad sorteringsprocess, undersöka relevant teknik, utvärdera tekniken baserad på vetenskaplig litteratur och tester. Testningen genomfördes i samarbete med två företag. Nära-infraröda skannrar testades med Holger AB, medan mönsterigenkänning system testades med Vision-Geek. Slutligen utvecklades tre koncept för den automatiserade sorterings processen och visades genom flödesscheman och 2D-3D-illustrationer. Resultat Resultaten av detta arbete visade att det var möjligt att använda nära-infraröd och mönsterigenkänning för separering av plastgolv. Dessutom genererades tre konceptuella lösningar för en automatiserad sorteringsprocess och visades med schematiska grafer och 2D-3D-illustrationer. Begreppen beskriver hur sorterings processen fungerar och vilken teknik som används för varje steg i processen. Koncept 1 och Koncept 2 använde både mönsterigenkänning och spektroskopi metoder. Medan Koncept 3 bara använde spektroskopi metoder. Spektroskopi metoderna användes för att sortera plastgolv efter innehåll medan mönsterigenkänning efter utseende. Slutsats Återvinning av sönderrivna plastgolv kan vara fördelaktigt för både miljön och återvinningsindustrin. Dock finns det några utmaningar med anknytning till pålitlig, snabb och icke-förstörande identifiering för sorterings- och separation ändamål. Ny och beprövad teknik som nästan infraröd hyperspektral avbildning och mönsterigenkänning kan användas. Emellertid måste mönster- och spektrum bibliotek av hög kvalitet av flera plastgolv skapas för optimala och pålitliga referens-modeller. Dessutom måste mönsterigenkänning och nära-infraröda metoder testas vidare i industriell skala.
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Phan, Phong Thanh. "Development of a multi-distance, multi-channel broadband near-infrared spectroscopy system to investigate the spatial variation in cellular oxygen metabolism in the healthy and injured adult human brains." Thesis, University College London (University of London), 2018. http://discovery.ucl.ac.uk/10042965/.
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This PhD thesis describes the progressive development of a multi-channel, multi-distance broadband NIRS system designed to measure the concentration changes in oxygenated haemoglobin (HbO2), deoxygenated haemoglobin (HHb), and especially the oxidation state of cytochrome-c-oxidase (oxCCO) across multiple regions of the adult human brain. The system was developed using an iterative approach, through two major iterations. At each iteration, in vivo tests in healthy adult volunteers were performed to test the system capability. The first iteration was the pseudo broadband diffuse optical tomography system, achieved by physically moving one source fibre and eight detector fibres across multiple positions in a fixed 3D printed probe holder. A functional activation task involving the visual cortex was used as an in vivo test of this approach. The second iteration was the full multi-channel, multi-distance broadband NIRS system, achieved by increasing the number of source and detector fibres and integrating a time-multiplexing mechanism for the sources. The capability of this system was tested using functional activation tasks involving both the visual and frontal cortices. The final version of the system was then used in the neurointensive care unit to monitor the frontal regions of patients with acute brain injury, demonstrating the capability for monitoring the temporal and spatial variations in cerebral haemodynamics and oxygen metabolism. The multi-channel, multi-distance broadband NIRS measurements acquired from various functional activation studies and the clinical study have provided evidence for the existence of spatially dependent changes in [oxCCO] signal. More importantly, they show that the spatial variation in the changes in [oxCCO] can be monitored using a multi-channel broadband NIRS approach. The measurements collected during various stages of system development have allowed the implementation of the oxCCO image reconstruction algorithm, reconstructing 3D tomographic images of oxCCO for the first time. The combined developments in hardware engineering, data acquisition, clinical studies and image reconstruction open up a whole new avenue for the investigation of cerebral oxygen metabolism in the healthy and injured adult human brain.
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Baker, Joseph Michael. "Concurrent neurological and behavioral assessment of number line estimation performance in children and adults." DigitalCommons@USU, 2013. https://digitalcommons.usu.edu/etd/1948.
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Children who struggle to learn math are often identified by their poor performance on common math learning activities, such as number line estimations. While such behavioral assessments are useful in the classroom, naturalistic neuroimaging of children engaged in real-world math learning activities has the potential to identify concurrent behavioral and neurological correlates to poor math performance. Such correlates may help pinpoint effective teaching strategies for atypical learners, and may highlight instructional methods that elicit typical neurological response patterns to such activities. For example, multisensory stimulation that contains information about number enhances infants' and preschool children's behavioral performance on many numerical tasks and has been shown to elicit neural activation in areas related to number processing and decision-making. Thus, when applied to math teaching tools, multisensory stimulation may provide a platform through which both behavioral and neural math-related processes may be enhanced. Common approaches to neuroimaging of math processing lack ecological validity and are often not analogous to real-world learning activities. However, because of its liberal tolerance of movement, near-infrared spectroscopy (NIRS) provides an ideal platform for such studies. Here, NIRS is used to provide the first concurrent examination of neurological and behavioral data from number line estimation performance within children and adults. Moreover, in an effort to observe the behavioral and neurological benefits to number line estimations that may arise from multisensory stimulation, differential feedback (i.e., visual, auditory, or audiovisual) about estimation performance is provided throughout a portion of the task. Results suggest behavioral and neural performance is enhanced by feedback. Moreover, significant effects of age suggest young children show greater neurological response to feedback, and increase in task difficulty resulted in decreased behavioral performance and increased neurological activation associated with mathematical processing. Thus, typical math learners effectively recruit areas of the brain known to process number when math activities become increasingly difficult. Data inform understanding typical behavioral and neural responses to real-world math learning tasks, and may prove useful in triangulating signatures of atypical math learning. Moreover, results demonstrate the utility of NIRS as a platform to provide simultaneous neurological and behavioral data during naturalistic math learning activities.
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Benselfelt, Tobias. "Flow Cytometry Sensor System Targeting Escherichia Coli as an Indicator of Faecal Contamination of Water Sources." Thesis, Linköpings universitet, Teknisk biologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-108004.
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Poor water quality is a global health concern affecting one billion people around the world. It is important to monitor water sources in order to maintain the quality of our drinking water and to avoid disease outbreaks. Targeting Escherichia coli as a faecal indicator is a widely used procedure, but the current methods are time consuming and not adequate to prevent spreading of faecal influence. This Master thesis demonstrates the development of a near infrared fluorescence flow cytometer sensor system targeting Escherichia coli, using fluorescently labeled chicken IgY antibodies. The near infrared light was chosen to avoid fluorescence from blue-green algae that are present in the water source. The hardware was developed with a 785 nm laser line to detect Alexa Fluor 790 labeled antibodies, using a photomultiplier tube or two different CMOS cameras. The antibodies were labeled using a commercial labeling kit, and evaluated using antibody binding assays and the developed hardware. The IgY antibodies were successfully labeled with Alexa Fluor 790 and the function was maintained after the labeling process. The result demonstrates the principles of the sensor system and how it solved to the problem with fluorescence from blue-green algae. An aperture was used to overcome the suboptimal laser and filter setup, and to increase the sensitivity of the system. However, only a small fraction of the cells could be detected, due to challenges with the focal depth and loss of sensitivity in the photomultiplier tube at near infrared wavelengths. Further development is required to create a working product.
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Mota, Carolina Pimenta. "Sistema de visão por infravermelho próximo para monitoramento de processos de soldagem a arco." Universidade Federal de Uberlândia, 2011. https://repositorio.ufu.br/handle/123456789/14895.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorVision, the human being s favorite sense, and its great capacity to obtain, to process and to interpret great amount of visual nature data has been throughout the years a great inspiration for development of techniques and technological devices that reproduce it into a computational system. In welding processes, vision can supply information in inspection and welded joint s quality, in the parameters monitoring, in trajectory correction and even, finally, in the study of the phenomena involved in the process. However, the luminosity/radiation emitted from the weld arc represents a barrier for these studies based in the process visualization. One of the forms currently used to visualize the process, without the interference of the arc s light, consists of illuminating the process with the near infrared light and, using band pass (interference) filters, around this exactly wave length, during the acquisition of the images. A solution for the near infrared illumination, of increasing application, involves the use of laser diodes of high power, with low cost and less complex installation than conventional lasers. Therefore, the proposal of this work is the project, construction and assessment of a vision system for welding processes with low cost and high flexibility. It is based on characterization of the spectrum of the weld arc, definition of a drive topology for the laser diode within its limitations of use and maximizing the emitted luminous power, built of control circuits, selection of optics equipment and components and, finally, project and application of a prototype for visualization of different arc-welding processes. The electrical system was validated by computational simulations and experimental burnout and stress tests. The final assessment of the whole vision system was carried out during TIG and MIG/MAG welding. Although, during the welding, the system was not capable of overcome the arc radiation, it provides a homogenous illumination in synchronism with the camera, which represents the main limitation due to its large shutter. Eventually, it s suggested to employ the developed vision system for helping joint tracking.
A visão, o sentido predileto do ser humano, e sua grande capacidade de captar, processar e interpretar grandes quantidades de dados de natureza visual tem sido, ao longo dos anos, um grande estímulo para o desenvolvimento de técnicas e de dispositivos tecnológicos que a reproduzam um sistema computacional. Nos processos de soldagem, a visão pode fornecer dados desde na inspeção e qualidade da junta soldada, no monitoramento de parâmetros, na correção de trajetórias até, por fim, no estudo dos fenômenos envolvidos no processo. Porém, a radiação luminosa emitida pelo arco representa uma barreira para tais estudos baseados na visualização do processo. Uma das formas utilizadas atualmente para se obter a visualização do processo, sem a interferência do arco, consiste em iluminar o processo com o infravermelho próximo e utilizar filtros de interferência (passa-faixa), em torno deste mesmo comprimento de onda, durante a aquisição das imagens. Uma solução para a iluminação infravermelha, de aplicação crescente, envolve o uso de diodos laser de alta potência, com baixo custo e menor complexidade de instalação do que os lasers convencionais. Desta forma, a proposta deste trabalho foi a criação de um sistema de visão dos processos de soldagem a arco, de baixo custo e alta flexibilidade, indo desde a caracterização dos espectros de emissão luminosa do arco, passando pela criação de uma topologia de acionamento para o diodo de alta potência no infravermelho próximo, respeitando suas limitações de uso e maximizando a potência luminosa emitida, criação dos circuitos de controle, escolha dos equipamentos e componentes ópticos e, por fim, projeto e aplicação de um protótipo em processos de soldagens. O sistema elétrico foi validado por simulações computacionais e testes experimentais de burnout e de stress, e as limitações do sistema de visão, como um todo, foram encontradas através e sua aplicação com soldagens TIG e MIG/MAG. Nestes ensaios, embora não tenha sido capaz de sobrepor a luz do arco, o sistema desenvolvido proporcionou uma iluminação homogênea e em sincronia com a câmera, onde a principal limitação foi o grande tempo de exposição da câmera disponível. Sugere-se, ao final, utilizar o sistema na forma de um seguidor de juntas.
Mestre em Engenharia Mecânica
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Froning, Cynthia Suzanne. "The near-infrared properties of compact binary systems /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
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Bambara, Gisèle. "Evaluation de la performance des ouvrages hydrauliques en remblai soumis à la présence de végétation arborescente." Thesis, Aix-Marseille, 2016. http://www.theses.fr/2016AIXM4301/document.
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L’évaluation de la performance des ouvrages hydrauliques en remblai est un enjeu majeur pour les gestionnaires en charge de leur sécurité. Qu'il s'agisse de digues ou de barrages, la présence de végétation arborescente représente un facteur de fragilité important. Deux types de mécanismes de détérioration peuvent ainsi être initiés ou aggravés : l’érosion interne et l’érosion externe. Or, ce facteur n’a été pris en compte que partiellement dans les modèles d’évaluation existants. De plus, les petits barrages en remblai peuvent avoir des dispositifs d’étanchéité différents et ne sont pas toujours équipés de drains et d’instruments d’auscultation: il est alors nécessaire d’adapter les modèles à chaque cas. L’objectif de la thèse est de répondre à ces verrous scientifiques. Les résultats de nos recherches concernent l’établissement de modèles d’évaluation de la performance basés sur des approches à base de connaissances.La démarche a été appliquée sur des ouvrages réels : 3 tronçons de digues de protection contre les inondations ainsi que 7 barrages en remblai ce qui nous a permis de montrer sa pertinence et donc son potentiel d’utilisation opérationnelleThe performance assessment of embankment hydraulic works is a major challenge for managers in charge of their security. For both dikes and dams, the presence of trees represents an important fragility factor. Two types of deterioration mechanism can thus be initiated or aggravated: internal erosion or scouring. However, this factor has been taken only partially into account in existing assessment models. In addition, small embankment dams can have different sealing devices and are not always equipped with drains and monitoring instruments: it is thus necessary to customize the models in each case. The aim of the thesis was to remove these scientific obstacles. The results of our research concern the design of performance assessment models relying on knowledge-based approaches.The approach was implemented for real works: three sections of river dikes and seven small embankment dams which allowed us to show its relevance and therefore its operational potential
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Zhang, Hongyi. "Road surface condition detection for autonomous vehicle by NIR LED system and machine learning approaches." Thesis, université Paris-Saclay, 2022. http://www.theses.fr/2022UPAST106.
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Le domaine des véhicules autonomes a suscité un grand intérêt ces dernières années. Afin de garantir au passager une expérience sûre et confortable sur les véhicules autonomes, des systèmes d'obstacles avancés doivent être mis en œuvre. Bien que les solutions actuelles de détection d'obstacles aient montré de bonnes performances, elles doivent être encore améliorées pour une sécurité accrue des véhicules autonomes sur route, de jour comme de nuit. En particulier, les véhicules autonomes dans la vie réelle peuvent rencontrer de la glace, de la neige ou des flaques d'eau, qui peuvent être la cause de collisions graves et d'accidents de la circulation. Les systèmes de détection doivent donc permettre de détecter les changements d'état de la route pour anticiper la réaction du véhicule et/ou désactiver les fonctions automatisées. L'objectif de cette thèse est de proposer un système pour les véhicules autonomes afin de détecter les conditions de chaussée induites par la météo. Après une étude approfondie de l'état de l'art, un système proche infrarouge (NIR) basé sur des LED et un système d'apprentissage automatique sont proposés pour la détection diurne et nocturne. Le système NIR a été conçu puis validé expérimentalement et, les spécifications techniques du système ont été définies. Le système d'apprentissage automatique est de plus proposé comme solution complémentaire au système NIR. Différents modèles d'apprentissage ont été testés et comparés en termes de performance. Enfin, les résultats sont discutés et une combinaison des deux systèmes est proposée afin de garantir une performance accrue pour la reconnaissance des conditions de routeThe field of autonomous vehicles has aroused great interest in recent years. In order to ensure the passenger to get a safe and comfortable experience on autonomous vehicles, advanced obstacle systems have to be implemented. Although current solutions for detecting obstacles have shown quite good performances, they have to be improved for an increased safety of autonomous vehicles on road, both in day-time and night-time conditions. In particular, autonomous vehicles in real life may encounter ice, snow or water puddles, which may be the cause of severe crashes and traffic accidents. The detection systems must hence allow detecting changes in road conditions to anticipate the vehicle reaction and/or deactivate the automated functions. The aim of this thesis is to propose a system implemented on the autonomous vehicles in order to detect the road surface conditions induced by the weather. After deep investigation of the state of art, a near infrared (NIR) system based on LEDs and a machine learning system were proposed for daytime and night-time detection. The NIR systems with three LEDs were investigated with experimental validations. In addition, the specifications of the NIR systems are carefully discussed. Furthermore, the machine learning system is proposed as a supplementary system. The performance of different models is compared in terms of classification accuracy and model complexity. Finally, the results are discussed and a combination of the two systems is proposed
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Ertel, S., D. Defrère, O. Absil, Bouquin J. B. Le, J. C. Augereau, J. P. Berger, N. Blind, et al. "A near-infrared interferometric survey of debris-disc stars." EDP SCIENCES S A, 2016. http://hdl.handle.net/10150/622442.
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Context. Extended circumstellar emission has been detected within a few 100 milli-arcsec around >= 10% of nearby main sequence stars using near-infrared interferometry. Follow-up observations using other techniques, should they yield similar results or non-detections, can provide strong constraints on the origin of the emission. They can also reveal the variability of the phenomenon. Aims. We aim to demonstrate the persistence of the phenomenon over the timescale of a few years and to search for variability of our previously detected excesses. Methods. Using Very Large Telescope Interferometer (VLTI)/Precision Integrated Optics Near Infrared ExpeRiment (PIONIER) in H band we have carried out multi-epoch observations of the stars for which a near-infrared excess was previously detected using the same observation technique and instrument. The detection rates and distribution of the excesses from our original survey and the follow-up observations are compared statistically. A search for variability of the excesses in our time series is carried out based on the level of the broadband excesses. Results. In 12 of 16 follow-up observations, an excess is re-detected with a significance of >2 sigma, and in 7 of 16 follow-up observations significant excess (>3 sigma) is re-detected. We statistically demonstrate with very high confidence that the phenomenon persists for the majority of the systems. We also present the first detection of potential variability in two sources. Conclusions. We conclude that the phenomenon responsible for the excesses persists over the timescale of a few years for the majority of the systems. However, we also find that variability intrinsic to a target can cause it to have no significant excess at the time of a specific observation.
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Ikpe, Stanley A. Triplett Gregory Edward. "Atmospheric effects on near-infrared free space optical communication links." Diss., Columbia, Mo. : University of Missouri--Columbia, 2009. http://hdl.handle.net/10355/6654.
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Title from PDF of title page (University of Missouri--Columbia, viewed on March 10, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Thesis advisor: Dr. Gregory E. Triplett Jr. Includes bibliographical references.
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Fernando, Nilmi T. "Novel Near-Infrared Cyanine Dyes for Fluorescence Imaging in Biological Systems." Digital Archive @ GSU, 2011. http://digitalarchive.gsu.edu/chemistry_diss/57.
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Heptamethine cyanine dyes are attractive compounds for imaging purposes in biomedical applications because of their chemical and photophysical properties exhibited in the near-infrared region. A series of meso amino-substituted heptamethine cyanine dyes with indolenine, benz[e]indolenine and benz[c,d]indolenine heterocyclic moieties were synthesized and their spectral properties including fluorescence quntum yield were investigated in ethanol and ethanol/water mixture. Upon substitution with amines, the absorption maxima of the dyes shifted to the lower wavelength region (~600 nm), showed larger Stokes shifts and stronger fluorescence which can be attributed to an excited state intramolecular charge transfer (ICT). High quantum yields were observed for primary amine derivatives and lower quantum yields were observed for secondary amine derivatives. Fluorescence quantum yields are greater for dyes with 3H-indolenine terminal moieties than for dyes with benz[e]indolenine end groups. Benz[c,d]indolenine based heptamethine cyanine dyes exhibited the lowest quantum yield due to aggregation in solution. In general, the benz[e]indolenine hepatemethine cyanines showed high Stokes shifts compared to indolenine dyes. For the meso-chloro dyes, the absorption maxima for the dyes shifted bathochromically in the order of indolenine, benz[e]indolenine and benz[c,d]indolenine.
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Izzetoglu, Kurtulus Onaral Banu. "Neural correlates of cognitive workload and anesthetic depth : fNIR spectroscopy investigation in humans /." Philadelphia, Pa. : Drexel University, 2008. http://hdl.handle.net/1860/2896.
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Rodigas, Timothy John. "High-Contrast Near-Infrared Studies of Planetary Systems and their Circumstellar Environments." Diss., The University of Arizona, 2013. http://hdl.handle.net/10150/306772.
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Planets are thought to form in circumstellar disks, leaving behind planetesimals that collide to produce dusty debris disks. Characterizing the architectures of planetary systems, along with the structures and compositions of debris disks, can therefore help answer questions about how planets form. In this thesis, I present the results of five papers (three published, two in preparation) concerning the properties of extrasolar planetary systems and their circumstellar environments. Chapters 2 and 3 are studies of radial velocity (RV) exoplanetary systems. For years astronomers have been puzzled about the large number of RV-detected planets that have eccentric orbits (e>0.1). In Chapter 2 I show that this problem can partially be explained by showing that two circular-orbit planets can masquerade as a single planet on an eccentric orbit. I use this finding to predict that planets with mildly eccentric orbits are the most likely to have massive companions on wide orbits, potentially detectable by future direct imaging observations. Chapter 3 presents such a direct imaging study of the 14 Her planetary system. I significantly constrain the phase space of the putative candidate 14 Her c and demonstrate the power of direct imaging/RV overlap. Chapters 4 and 5 are high-contrast 2-4 μm imaging studies of the edge-on debris disks around HD 15115 and HD 32297. HD 15115's color is found to be gray, implying large grains 1-10 μm in size reside in stable orbits in the disk. HD 32297's disk color is red from 1-4 μm. Cometary material (carbon, silicates, and porous water ice) are a good match at 1-2 μm but not at L'. Tholins, organic material that is found in outer solar system bodies, or small silicates can explain the disk's red color but not the short wavelength data. Chapter 6 presents a dynamical study of dust grains in the presence of massive planets. I show that the width of a debris disk increases proportionally with the mass of its shepherding planet. I then make predictions for the masses and orbits of putative planets in five well-known disks. In Chapter 7, I summarize and discuss plans for future research in the exoplanet field.
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Skvaril, Jan. "Near-Infrared Spectroscopy and Extractive Probe Sampling for Biomass and Combustion Characterization." Doctoral thesis, Mälardalens högskola, Framtidens energi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-35041.
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Biomass is characterized by highly variable properties. It can be converted to more valuable energy forms and products through a variety of conversion processes. This thesis focuses on addressing several important issues related to combustion and pulping. Experimental investigations were carried out on a biomass-fired industrial fluidized-bed boiler. The observed combustion asymmetry was explained by an imbalance in the fuel feed. Increased levels of carbon monoxide were detected close to boiler walls which contribute significantly to the risk of wall corrosion. Moreover, extensive literature analysis showed that near-infrared spectroscopy (NIRS) has a great potential to provide property information for heterogeneous feedstocks or products, and to directly monitor processes producing/processing biofuels in real-time. The developed NIRS-based models were able to predict characteristics such as heating value, ash content and glass content. A study focusing on the influence of different spectra acquisition parameters on lignin quantification was carried out. Spectral data acquired on moving woodchips were found to increase the representativeness of the spectral measurements leading to improvements in model performance. The present thesis demonstrates the potential of developing NIRS-based soft-sensors for characterization of biomass properties. The on-line installation of such sensors in an industrial setting can enable feed-forward process control, diagnostics and optimization.
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Milli, J., A. Vigan, D. Mouillet, A. M. Lagrange, J. C. Augereau, C. Pinte, D. Mawet, et al. "Near-infrared scattered light properties of the HR 4796 A dust ring." EDP SCIENCES S A, 2017. http://hdl.handle.net/10150/623201.
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Context. HR4796A is surrounded by a debris disc, observed in scattered light as an inclined ring with a high surface brightness. Past observations have raised several questions. First, a strong brightness asymmetry detected in polarised reflected light has recently challenged our understanding of scattering by the dust particles in this system. Secondly, the morphology of the ring strongly suggests the presence of planets, although no planets have been detected to date. Aims. We aim here at measuring with high accuracy the morphology and photometry of the ring in scattered light, in order to derive the phase function of the dust and constrain its near-infrared spectral properties. We also want to constrain the presence of planets and set improved constraints on the origin of the observed ring morphology. Methods. We obtained high-angular resolution coronagraphic images of the circumstellar environment around HR4796A with VLT/SPHERE during the commissioning of the instrument in May 2014 and during guaranteed-time observations in February 2015. The observations reveal for the first time the entire ring of dust, including the semi-minor axis that was previously hidden either behind the coronagraphic spot or in the speckle noise. Results. We determine empirically the scattering phase function of the dust in the H band from 13.6 degrees to 166.6 degrees. It shows a prominent peak of forward scattering, never detected before, for scattering angles below 30 degrees. We analyse the reflectance spectra of the disc from the 0.95 mu m to 1.6 mu m, confirming the red colour of the dust, and derive detection limits on the presence of planetary mass objects. Conclusions. We confirm which side of the disc is inclined towards the Earth. The analysis of the phase function, especially below 45 degrees, suggests that the dust population is dominated by particles much larger than the observation wavelength, of about 20 mu m. Compact Mie grains of this size are incompatible with the spectral energy distribution of the disc, however the observed rise in scattering efficiency beyond 50 degrees points towards aggregates which could reconcile both observables. We do not detect companions orbiting the star, but our high-contrast observations provide the most stringent constraints yet on the presence of planets responsible for the morphology of the dust.
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Adedipe, Oluwatosin Emmanuel. "Application of process analytical technology to wood a near infrared spectroscopy approach /." Morgantown, W. Va. : [West Virginia University Libraries], 2008. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=6037.
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Thesis (Ph. D.)--West Virginia University, 2008.Title from document title page. Document formatted into pages; contains xi, 98 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 47-52).
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Concia, Massimo. "Fluorescence labeled PEI-based gene delivery systems for near infrared imaging in nude mice." Diss., lmu, 2010. http://nbn-resolving.de/urn:nbn:de:bvb:19-113095.
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Li, Hejie. "Near-infrared diode laser absorption spectroscopy with applications to reactive systems and combustion control /." May be available electronically:, 2007. http://proquest.umi.com/login?COPT=REJTPTU1MTUmSU5UPTAmVkVSPTI=&clientId=12498.
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Zhang, Lin. "PATTERN RECOGNITION METHODS FOR THE ANALYSIS OF INFRARED IMAGING DATA AND MULTIVARIATE CALIBRATION STANDARDIZATION FOR NEAR-INFARED SPECTROSCOPY." Ohio : Ohio University, 2002. http://www.ohiolink.edu/etd/view.cgi?ohiou1013445546.
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Long, Robert Llewellyn, and bizarrealong@hotmail com. "Improving fruit soluble solids content in melon (Cucumis melo L.) (reticulatus group) in the Australian production system." Central Queensland University. Biological and Environmental Science, 2005. http://library-resources.cqu.edu.au./thesis/adt-QCQU/public/adt-QCQU20051019.144749.
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Total soluble solids (TSS) is a reliable indicator of melon eating quality, with a minimum standard of 10% recommended. The state of Australian melon production with respect to this quality criterion was considered within seasons, between growing districts and over seasons. It was concluded that improvement in agronomic practice and varietal selection is required to produce sweeter melons. The scientific literature addressing melon physiology and agronomy was summarised, as a background to the work that is required to improve melon production practices in Australia.
The effect of source sink manipulation was assessed for commercially grown and glasshouse grown melon plants. The timing of fruit thinning, pollination scheduling, the application of a growth inhibitor and source biomass removal were assessed in relation to fruit growth and sugar accumulation. Results are interpreted against a model in which fruit rapidly increase in weight until about two weeks before harvest, with sugar accumulation continuing as fruit growth ceases. Thus treatment response is very dependant on timing of application. For example, fruit thinning at 25 days before harvest resulted in further fruit set and increased fruit weight but did not impact on fruit TSS (at 9.8%, control 9.3%), while thinning at 5 days before harvest resulted in a significant (Pless than 0.05) increase in fruit TSS (to 10.8%, control 9.3%) and no increase in fruit weight or number. A cost/ benefit analysis is presented, allowing an estimation of the increase in sale price required to sustain the implementation of fruit thinning.
The effect of irrigation scheduling was also considered with respect to increasing melon yield and quality. To date, recommended practice has been to cause an irrigation deficit close to fruit harvest, with the intent of 'drying out' or 'stressing' the plant, to 'bring on' maturity and increase sugar accumulation. Irrigation trials showed that keeping plants stress-free close to harvest and during harvest, facilitated the production of sweeter fruit.
The maintenance of a TSS grade standard using either batch based (destructive) sampling or (non-invasive) grading of individual fruit is discussed. On-line grading of individual fruit is possible using near infrared spectroscopy (NIR), but the applicability of the technique to melons has received little published attention. Tissue sampling strategy was optimised, in relation to the optical geometry used (in commercial operation in Australia), both in terms of the diameter and depth of sampled tissue. NIR calibration model performance was superior when based on the TSS of outer, rather than inner mesocarp tissue. However the linear relationship between outer and middle tissue TSS was strong (r2 = 0.8) in immature fruit, though less related in maturing fruit (r2 = 0.5). The effect of fruit storage (maturation/senescence) on calibration model performance was assessed. There was a negligible effect of fruit cold storage on calibration performance.
Currently, the agronomist lacks a cost-effective tool to rapidly assess fruit TSS in the field. Design parameters for such a tool were established, and several optical front ends compared for rapid, though invasive, analysis. Further, for visualisation of the spatial distribution of tissue TSS within a melon fruit, a two-dimensional, or hyper-spectral NIR imaging system based on a low cost 8-bit charge coupled device (CCD) camera and filter arrangement, was designed and characterised.
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Rameau, Julien, Katherine B. Follette, Laurent Pueyo, Christian Marois, Bruce Macintosh, Maxwell Millar-Blanchaer, Jason J. Wang, et al. "An Optical/Near-infrared Investigation of HD 100546 b with the Gemini Planet Imager and MagAO." IOP PUBLISHING LTD, 2017. http://hdl.handle.net/10150/624214.
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We present H band spectroscopic and H alpha photometric observations of HD 100546 obtained with the Gemini Planet Imager and the Magellan Visible AO camera. We detect H band emission at the location of the protoplanet HD 100546 b, but show that the choice of data processing parameters strongly affects the morphology of this source. It appears point-like in some aggressive reductions, but rejoins an extended disk structure in the majority of the others. Furthermore, we demonstrate that this emission appears stationary on a timescale of 4.6 years, inconsistent at the 2 sigma level with a Keplerian clockwise orbit at 59 au in the disk plane. The H band spectrum of the emission is inconsistent with any type of low effective temperature object or accreting protoplanetary disk. It strongly suggests a scattered-light origin, as this is consistent with the spectrum of the star and the spectra extracted at other locations in the disk. A nondetection at the 5 sigma level of HD 100546 b in differential H alpha imaging places an upper limit, assuming the protoplanet lies in a gap free of extinction, on the accretion luminosity of 1.7 x 10(-4) L-circle dot and M(M) over dot < 6.3 x 10(-7) M-Jup(2) yr(-1) for 1 R-Jup. These limits are comparable to the accretion luminosity and accretion rate of T-Tauri stars or LkCa 15 b. Taken together, these lines of evidence suggest that the H band source at the location of HD 100546 b is not emitted by a planetary photosphere or an accreting circumplanetary disk but is a disk feature enhanced by the point-spread function subtraction process. This non-detection is consistent with the non-detection in the K. band reported in an earlier study but does not exclude the possibility that HD 100546 b is deeply embedded.
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Pang, Yulian [Verfasser], and Jochen [Akademischer Betreuer] Gutmann. "Photopolymerization with new LED systems emitting in the near infrared region / Yulian Pang ; Betreuer: Jochen Gutmann." Duisburg, 2021. http://d-nb.info/1230322655/34.
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Hu, Mo. "Neuroscience for Engineering Sustainability: Measuring Cognition During Design Ideation and Systems Thinking Among Students in Engineering." Thesis, Virginia Tech, 2018. http://hdl.handle.net/10919/91399.
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Sustainability is inherently a complex problem that requires new ways of thinking. To solve grand challenges such as climate change, environmental degradation, and poverty, engineers cannot rely on the same models of thinking that were used to create these problems. Engineering education is therefore critical to advance sustainable engineering solutions. Improving education relies on understanding of cognition of thinking and designing for sustainability. In this thesis, a nascent neuroimaging technology called functional near-infrared spectroscopy (fNIRS) was used to measure cognition among engineering students thinking about sustainability. fNIRS provides an opportunity to investigate how sustainability in design influences cognition, and how different concept generation techniques help students consider many aspects related to sustainability. The first manuscript provides evidence that engineering students perceive sustainability in design as a constraint, limiting the number of solutions for design and decreasing the cognitive efficiency to generate solutions. Senior engineering students generated fewer solutions than freshmen, however, seniors were better able to cognitively manage the sustainability parameter with higher cognitive efficiency. The second manuscript investigates the cognitive difference when generating concepts using concept listing or concept mapping. The results indicate that concept mapping (i.e. intentionally drawing relationships between concepts) leads to more concepts generated. An increase in concepts during concept mapping was also observed to shift cognitive load in the brain from regions associated with process sequencing to regions associated with cognitive flexibility. This research demonstrates the feasibility of fNIRS applied in engineering research and provides more understanding of the cognitive requirements for sustainability thinking.M. S.
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DeGraffenried, Jeffries Blunt. "Rapid prediction of tropical soil degradation using diffuse reflectance spectroscopy method verification in the Saiwa River basin, western Kenya /." Thesis, Birmingham, Ala. : University of Alabama at Birmingham, 2008. https://www.mhsl.uab.edu/dt/2010r/degraffenried.pdf.
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Gibson, Irish Alcalen. "Applications of diffuse reflectance near-infrared spectroscopy and cure kinetics study by differential scanning calorimetry to selected thermosetting polymer-based systems of interest in the aviation industry." Diss., Wichita State University, 2012. http://hdl.handle.net/10057/5357.
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Diffuse Reflectance Near-Infrared (near-IR) Spectroscopy combined with Partial Least Squares (PLS) regression was used to determine the moisture content and degree of cure in unfilled epoxy resins, carbon-reinforced epoxy resin and epoxy resin adhesives. PLS-generated calibration curves were consistently superior than the calibration curves based on Beer’s law. The same technique was also applied to polyimide-based prepregs to determine the degree of cure through the softening temperature, Ts. In both epoxy-based and polyimide-based systems, good correlations were established between the near-IR spectra and the properties of interest. The combination of the rapid, non-destructive technique coupled with a sophisticated chemometric software shows promise as a reliable technique that could be of great benefit to the aviation industry.
Another aspect of this study was the evaluation of an epoxy resin prepreg as a candidate material to be used in repair scenarios in the aviation industry. The prepreg was partially characterized using mid-IR and 1H NMR spectroscopies indicating that it contains diglycidyl ether of bisphenol-A (DGEBA) and diamino diphenyl sulfone (DDS) as a curing agent. Ramp and soak experiments using the Differential Scanning Calorimetry (DSC) were performed to study the cure kinetics. A recommended cure cycle was determined to be a combination of a dynamic heating to 150-155 °C at 2 °C/min and an isothermal heating at the end temperature for 20 minutes.Thesis (Ph.D.)--Wichita State University, College of Liberal Arts and Sciences, Dept. of Chemistry
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Edlund, Kajsa, and Ali Ahmad Shahnawazi. "Real-time characterization of fuel by Near-Infrared spectroscopy : Quantitative measurements of moisture content, ash content, heating value, and elemental compositions in solid biofuel mixtures." Thesis, Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-55231.
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The global energy demand supplies mainly from fossil fuels, which is neither sustainable nor environmentally friendly and aims to global warming. Therefore, both more investments in renewable energy sources such as bioenergy are required, as well as new technologies such as carbon capture and storage (CCS) to handle the emissions from existing combined heat and power (CHP) plants. In this degree project, the focus is to determine the moisture content, ash content, heating value, and elemental compositions of solid biofuel mixtures in real-time by utilizing the optical technique of near-infrared (NIR) spectroscopy. A total number of 150 samples of solid biofuel mixtures were prepared and illuminated by NIR light. All spectra of the samples were recorded in a wavenumber range of 12000 cm-1 – 400 cm-1 in a dish on a turn table which was in a moving mode with a speed of 0.5 m/s. Each sample was scanned three times to avoid, or at least minimize the deviation of the spectra and the samples were mixed between each scan to get more reliable representative spectra data. Partial least square regression models were created to analyze the spectra data. A data split was done randomly, 100 for calibration and 50 for validation. Then the data was pre-processed with different methods including multiplicative scatter correction (MSC), standard normal variate (SNV), Savitzky-Golay 1st derivative (SG 1st), Savitzky-Golay 2nd derivative (SG 2nd), and orthogonal signal correction (OSC) to reduce noise and scatter effect. The results of NIR spectra treated by OSC method obtained , RMSE and SE of 0.900, 2.241 and 2.204, respectively for prediction of moisture content, 0.424, 0.913 and 0.922 for prediction of ash content, 0.640, 0.370 and 0.368 for prediction of heating value, respectively. The obtained prediction of , RMSE and SE were 0.687, 0.066 and 0.058 for nitrogen, 0.636, 0.361 and 0.364 for carbon, 0.483, 0.269 and 0.270 for hydrogen, respectively. As the results shows, these models to predict the ash content and hydrogen content has a lower accuracy than what is expected in process modeling while the prediction of moisture content has the highest accuracy.
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Jhou, Huankai, and 周煥凱. "Optical System Design For Near Infrared Surveillance Devices." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/49984655471419034625.
Full textAbstract:
碩士明道大學
光電暨能源工程學系碩士班
100
The purpose of this study , is to design a near infrared optical system surveillance devices by using optical design software to improve the traditional surveillance devices ability of distinguishing in the environment during the night. This thesis adopts starlight night vision goggles “image intensifier tube” combining with the traditional surveillance devices , utilize , “image intensifier tube” , have to faint light high power to lead linear to enlarge characteristic and lens design , to make up a near infrared surveillance devices. In conclusion , the designing of the optical lens of low luminosity and relay lens , enable image intensifier tube with CCD coupling, and this optical system is mainly modulated the transfer function with MTF to assess it’s a quality standard of formation of image , and the system can be made after optimize by optical simulate software. Keywords: near infrared, surveillance devices, image intensifier tube,
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Wang, Sheng-Wei, and 王聖維. "Application of Near Infrared Heart Rate Detection System." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/q8ps5a.
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碩士國立臺北科技大學
電子工程系研究所
104
In recent year, traditional contact instruments are the gold standrad techniques for measurement of the heart rate. But traditional contact measurement instruments can cause a lot of inconvenience. Current, Non-Contact Imaging Photoplethysmography (iPPG) have been proven to feasible measurement vital signs. Non-Contact measurments can provide a more comfortable physiological assessment ,and alos more suitable for long-term monitoring at home or hospital medical care. However now it susceptible to limit ambient light intensity. In this paper, we will use near-infrared (NIR) characteristics and image processing overcome this problem. With near-infrared spectrum as a dedicated light source to penetrate through the skin. Using Python5000 Gen3 image sensor camera, constitute of a non-invasive, non-contact measurement system. Further more system measure the distance to reach 1.2 meters away and reducing ambient lighting effects heart rate measurement. Image processing conversion in RAW data format, by using discrete wavelet transform (DWT) fast segmentation image in to different frequency bands. It is for Eulerian Magnification (EM) to process image for visualizing variation of the human pluse recorded by image sensor. After finite impulse filter (FIR), heart pulse is filtered waveform signal. This paper presents an approch to reduce the ambient light of non-contact Imaging Photoplethysmography heart rate measurement system. As a result of Bland Altman value analysis with traditional contact heart rate measurement the mean difference 1.1, and compare with the commercially high-end webcam raised the mean difference 2.8, which includes accurate measurements make it a relatively broad application.
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Wang, Li-wei, and 王立威. "A study of rice inspection system using near-infrared imaging." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/53886825143450469154.
Full textAbstract:
碩士國立雲林科技大學
電子與光電工程研究所碩士班
100
This study explored the possibility to increase the classification rates between rice and other impurities like glass or plastic by choosing proper NIR illumination light source. Using intensity of the sample as the criterion, image processing and distribution of intensity are designed for contrast with samples images. Then we combine the neural networks technology and image processing to establish a structure to recognize the authenticity of rice. In the parameters of the neural network design set one hidden layer and four neurons for the results with stability. From neural network analysis of the results, the classification rates could be reached 100%. Based on the results, it is concluded that the system is sufficient to use for inspection between rice and impurities based on the reflection intensity of samples under illumination in NIR. The 980nm for NIR laser is used to select the illumination light source of samples to improve the contrast of CCD images. The authenticity of rice recognizes system can be increase by using NIR images, which is generally used in industry nowadays. It’s able to expect that if the working wavelengths enlarged to the longer infrared ranges, higher classification rates can be achieved. But, the device for long infrared is more high-priced and the working environments are limited, and therefore using near-infrared is the most saving cost and helpful solution for classification of rice.
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Chen, Ssu-Cheng, and 陳思成. "The Near-Infrared Electro-Optics Modulation Coding System with USB Interface." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/87624090599380379828.
Full textAbstract:
碩士逢甲大學
電機工程所
96
The purpose of thesis is to design a near-infrared (NIR) Electro-Optics Modulation Coding System. The optical signal produced from LED is modulated by using the concept of the Free Space Optics(FSO). The Electro-Optics circuit receives the optical signal through the PIN-photodiode, and combines the micro processor with USB interface to form a control platform connecting the computer. It builds a friendly Graphical User Interface (GUI). In order to use the system in daily life, the circuit must be designed to isolate the impact of the noise powerfully. It would help the optical signal to be transmitted and received efficiently. Through signal processing unit, we overcome the problem caused by the noise of the external environment. We also verify the accuracy of the optical signal modulation coding. The system can code in the general environment, and the error rate is less than 0.03%. The working range is up to 1 meter.
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Jiang, Jhen-Rong, and 江振榮. "Design of multi-channel high frequency functional near-infrared spectroscopy system." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/78404506013950012050.
Full textAbstract:
碩士國立成功大學
醫學工程研究所碩博士班
94
Two major types of optical signals following functional brain activation can be observed, the slow hemodynamic signal and the fast neuronal signal. The fast neuronal signal is supposedly related to neuronal activity, but its intensity is small and difficult to detect. The aim of this study was to set up a multi-channel high frequency fNIRS system for detecting the slow hemodynamic as well as the fast neuronal signals. We utilized high-frequency intensity-modulated light source through optical fiber to illuminate the medium. The modulated frequency was changed from 10 KHz up to 125 MHz used in our previous study. Instead of photodiode, high sensitivity photomultiplier tube (PMT) with Peltier cooling system was applied to detect scattering light and transform optical signal into electrical signal. The low frequency I and Q components from mixed signals were acquired from the analog in-phase and quadrature (IQ) demodulator for deriving the amplitude and phase information. The designed high frequency fINRS system was first calibrated in phantom in which the intralipid was used as scatter for varied amount of ink absorber. Under the phantom setup, we varied the modulated frequencies, the source-to-detector distance, and the concentration of intralipid-ink solution for validation purposes. Our observations on the amplitude attenuation and phase shift coincided with those of previous studies. The designed high frequency fNIRS system could be applied to brain activities of animal experiments and neuronal activities of cultured neurons in future studies.
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Huang, YunJung, and 黃韻容. "A Near-Infrared Photothermal Transcutaneous Microneedle System for the Treatment of Infections." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/21263418629914306028.
Full textAbstract:
碩士國立清華大學
奈米工程與微系統研究所
102
Photothermal therapy has been highly noticed as a new treatment method in research fields recently. This method is by using photothermal sensitive material with near infrared (IR) light. Those materials have great absorbance of near IR, and can transform the light energy into thermal energy. Provide a new way to treat cancer cells or bacteria infection. Due to the high penetration of laser and its collimation, combining with photothermal sensitive material can produce heat for the efficient treatment. Our goal is to combine the MEMS (Micro Electro Mechanical Systems, MEMS) technology to produce polypyrrole microneedle patch, build a new photothermal therapy devices. In recent years, by using MEMS technology, researchers developed a new medical equipment technology - microneedle. Polypyrrole (PPy) was mostly often focused on its conductive characteristic, but furthermore which has excellent photothermal conversion capability, light stability, and with its excellent biocompatibility, making PPy a very promising photothermal therapy material. In our in vitro experiments, we adjusted the power of the near IR to manipulate the temperature. We used 0.5 W/cm2, 808 nm near IR with PPy microneedles to precede our experiment. In animal experiments, we demonstrate that this device has a good effect of bacterial inhibition. Prove the great potential of the PPy microneedle in photothermal therapy.
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Huang, Che-Cheng, and 黃哲政. "The Near Infrared Light emitting diode (IRLED) for FM voice communication system." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/72127187485467867680.
Full textAbstract:
碩士國立中央大學
光電科學研究所
91
The near Infrared Light emitting diode (IRLED) for FM voice communication system is used near infrared radiation for carrier light source which be modulated by voice signal transmit from transmission port to received port by air, then the received signal demodulate back to the original voice signal. The system takes the FM for modulation method, which has larger signal-noise ratio, lower distortion and surrounding disturbance than AM and PM. The wireless communication is hot, such as blue tooth. Its advantage is wireless and unobstructive, but it easily interfere with each other and isn’t covert in density resident region. If infrared light is took as carrier light source, the problem can be solved. The article surveys how to use IRLED to setup the IR voice communication system and to use pre-emphasis and de-emphasis to lower the noise and improve the width and length of the transmission field.
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Wang, Kuan-Ju, and 王冠茹. "Measurement of brain activity by using functional near infrared spectroscopy(fNIRS) system." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/30597668873799104441.
Full textAbstract:
碩士國立成功大學
醫學工程研究所碩博士班
93
Functional near infrared spectroscopy (fNIRS) is a promising biophotonic functional imaging method to observe the optical properties of cells or tissues. Compared to other neuroimaging techniques, fNIRS is portable, affordable, non-radiative, and in good spatial-temporal resolution. The aims of this study were to develop a single-channel fNIRS system by using frequency-domain method and to validate the developed fNIRS on phantom as well as on ischemic stroke rats. Two laser diodes with wavelengths of 780 nm and 830 nm were modulated at 10 kHz carryier frequency and driven by constant current alternately switching at 5 Hz between two sources.. The optical output of high sensitivity photo detector was demodulated to extract amplitude and phase information by using digital in-phase and quadrature demodulator. The designed fNIRS was first calibrated in phantom study which consisted of Intralipid scatter and ink absorber. The light-intensity-voltage (LIV) curve was first to check the operation ranges of laser sources and was further to observe the effective source-detector distance by varying concentration of scatter and absorber. Later, the fNIRS was applied to investigate the concentration changes of oxy-hemoglobin in blood with stroke animal model study. The stroke rats were induced by the occlusion of middle cerebral artery combined the techniques of three-vessel occlusion to observe the time-course changes of ischemia by using fNIRS system. Our results showed that the reduction in blood flow at middle regions of lesion side were evident from the signals detected by our fNIRS system. By measuring the changes in light absorption at different wavelengths, tissue oxygenation can be measured continuously. Further development of the system with multichannel sensor probe with single-unit recording would be a viable device for studying the brain activity of neurological disorders.
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Rakhshani, Fatmehsari Younes. "Designing and Implementing a Portable Near-Infrared Imaging System for Monitoring of Human’s Functional Brain Activity." 2015. http://hdl.handle.net/1993/30245.
Full textAbstract:
Functional near-infrared spectroscopy (fNIRS) is a non-invasive technique for monitoring of brain functional activity. It uses near-infrared (NIR) light to get the information related to brain hemodynamic response as most of the tissues in the brain are transparent to NIR light.
The main goal of this study was to design, implement and evaluate a continuous-wave near-infrared spectroscopy (CW-NIRS) system for human’s brain cognitive functions. This system is portable, and works with a small rechargeable battery; thus, it may be used for bedside monitoring. In our CW-NIRS system, we used 3 multi-wavelength LEDs and 8 photodiodes (with built-in amplifiers) resulting in 12 channels (voxels). The collected signals of these 12 channels, at a sampling rate of 15 Hz, can be used for 2D image reconstruction to monitor functional brain activity. All LEDs and photodiodes are placed on a flexible printed circuit board (PCB), which covers the forehead to measure hemodynamic response of the prefrontal cortex. We also developed a software in MATLAB for analysis of optical signals recorded by our CW-NIRS system. This software provides 2D image reconstruction and monitoring of changes in concentration of oxygenated ([HbO2]) and deoxygenated ([HbR]) hemoglobin as well as the total hemoglobin ([HbT]) for the 12 channels over the prefrontal cortex (forehead). The software has also an embedded statistical analysis option for analyzing the collected signals and displaying the results.
The developed CW-NIRS system was evaluated on 14 individuals (24±3 years old) on two common cognitive tasks: verbal fluency task (VFT) and color distinction task (CDT). In both tests, we observed that as the cognitive task begins [HbO2] and [HbT] increase and [HbR] decreases, after a few seconds delay. Furthermore, at the end of the tasks as subjects close their eyes in the second rest state, all three hemodynamic signals converge toward baseline ([HbO2] and [HbT] decrease and [HbR] increases). Also, the difference between hemodynamic signals at the rest state and task state was highly significant (p < 9.95e-11) in all 12 channels and in both cognitive tasks. The results confirm the ability of the designed CW-NIRS system to detect functional brain activities.
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Feng-MaoYang and 楊豐懋. "Development of Near Infrared Spectroscopy System for Assessing Hemodynamic Changes of Rat’s Brain." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/06864279859233114578.
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Chen, Po-Chih, and 陳柏志. "Design and Validation of a Wireless Near-Infrared System for Oxygen Saturation Measurement." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/16825957790646387025.
Full textAbstract:
碩士國立交通大學
光電系統研究所
100
Oxygen saturation is the key parameter in physiological monitoring. Continuous measurement of oxygen saturation level is especially important to aged people, pregnant women, neonates and patients in critical situations which can lead to severe hypoxia in human tissues. In past study, the noninvasive measurement of oxygen saturation is mainly implemented by standard oximeter combined with transmission probes. However, the heavy, huge, wired system and the limitation of measurement locations of transmission probes may result in inconvenience and difficulty in daily life use. Hence, we propose a light, miniature, wireless oxygen saturation monitoring system that can be compatible not only with the standard transmission probe but also the designed reflectance probe that enhances the flexibility of measurements at different locations. With the applied optical techniques of Near-infrared spectroscopy (NIRS) and Photoplethysmography (PPG), the oxygen saturation can be measured noninvasively. In this study, the validations of the proposed system are performed by normal breathing task and breath holding task and the results are compared with the standard oximeter. In normal breathing task via forehead, the results show average correlation 82.78% between the proposed system and standard oximeter. In breath holding task via finger, the results show average correlation 88.40% between the proposed system and standard oximeter. In breath holding task via forehead, the results show average correlation 83.06% between the proposed system and standard oximeter. In conclusion, the proposed system is reliable and can be applied conveniently in daily life.
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Chen, Cheng-Yang, and 陳政揚. "A Precision Measurement System for Near-Infrared Absorption Spectrum of Biological Tissue Constituents." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/98260719917236877920.
Full textAbstract:
碩士中原大學
醫學工程研究所
95
Excimer laser coronary angioplasty (ELCA) uses an optical fiber catheter to deliver high power laser energy to remove plaque in occluded arteries. Since it is difficult to use X-ray image to accurately confirm the location of plaque from outside of body, it will be helpful to develop a spectral analysis method for detecting plaque on the tip of catheter. In order to distinguish plaque from normal vessel tissue, it is necessary to accurately measure their absorption spectra in the near-infrared region. In this study, an absorption spectrum measurement system with a variable sample path length and controllable sample temperature was built. The light absorbance can be kept at the range between 0.4 and 1.9 for measuring the absorption spectra, from 700nm to 1700nm, of water and fatty acids. The near-infrared absorption spectrum shows fatty acids have absorption peaks at 923nm, 1033nm, 1203nm, and 1386nm and the absorption peaks of water at 970nm and 1180nm. The absorption ratios calculated from the near-infrared reflectance of a thin layer of pork sample can be used to identify its water and fat content.