- 标题
- 摘要
- 关键词
- 实验方案
- 产品
过滤筛选
- 2015
- Calibration process of OSL detectors
- Iodine-131
- OSL-BeO
- Dosimetry of staff and patients
- Optically Stimulated Luminescence (OSL)
- Akdeniz University
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Real-time motorized electrical hospital bed control with eye-gaze tracking
摘要： Patients with motor neuron disease and most terminal patients cannot use their hands or arms, and so they need another person for their all needs. However, the mental functions and memories of such patients are generally sound, and they can control their eyes. Using an eye-gaze tracking technique, we have realized a real-time system for such patients. The system controls a motorized electrical hospital bed (EHB) by eye gaze with 4 degrees of freedom, using a low-cost webcam. Contactless systems that require calibration cannot be used for EHB control. The system developed in this work does not require any calibration process and it is contactless. These properties are the most innovative part of the proposed approach. To begin, the system detects the eye region and computes the iris centers. It then tracks the centers and moves a mouse pointer on a screen with the eye gaze. The speci(cid:12)c movements of the mouse pointer are evaluated as position changing requests and the completed movements of the mouse pointer change the EHB position electrically. The communication between the computer and the EHB is provided by a relay control card driven by Arduino Mega. The system works under day/arti(cid:12)cial lighting conditions successfully with or without eyeglasses. The system was tested with 30 volunteers on the EHB safely and was completed with 90% success (the exceptions being people with slanted eyes).
关键词： electrical hospital bed,Calibration-free eye tracking,real-time eye-gaze tracking,eye-based mouse control
更新于2025-09-23 15:21:21
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Intercomparison of Field Methods for Acquiring Ground Reflectance at Railroad Valley Playa for Spectral Calibration of Satellite Data
摘要： Ground reflectance was acquired at the Railroad Valley Playa calibration site in Nevada USA using different methods of collection. The data was collected near the time and date of Landsat 8 OLI and Sentinel-2 satellite overpasses so an inter-comparison could be made with the reflectance products to determine which method was more suitable for vicarious calibration. The field spectrometers and reference panels were characterized before the field campaign. A continuous acquisition method was compared to stop and measure collections. Both acquisition methods were collected along an 80 m east-west transect as well as for a series of north-south transects over an 80 x 320 m area, with the stop and measure method being performed at random sampling locations. The measurements were performed using two field spectrometers by three teams of two people to compare the repeatability. The aim of the field campaign was to determine the variability due to the operator and the method of collection.
关键词： Railroad Valley Playa,spectrometer,vicarious calibration,reflectance
更新于2025-09-23 15:21:21
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[IEEE 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - Trebic, Czech Republic (2018.9.18-2018.9.20)] 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - Novel Method of Total Spectral Radiant Flux Standard Realization
摘要： Modern metrology of SSL sources requires a modified approach to future realization of reference standards. This is caused by the fact that traditional broad band and omni-directional light sources used are being replaced by high intensity sources with a specific directional light intensity distribution. At the same time the importance of LED lighting quality assurance is increasing as this new type of lighting is currently replacing traditional light sources in many applications. The specifics of an integrating sphere-spectroradiometer measurement system require the calibration with the use of a reference standard with known Spectral Radiant Flux Distribution, Luminous flux as well as the Luminous Intensity Distribution (LID) to compensate for the sphere system non-uniform reflectance properties. This way the accuracy of the sphere system calibration will allow to measure various types of LED products in conformance with the EN 13032-4:2015, LED lamps, modules and luminaires modules, lamps regardless of their spatial distribution properties. This paper will cover basic concepts and details of a novel method of Total Spectral Radiant Flux (TSRF) realization and description of a TSRF standard facility developed for the Russian National Metrology Institute – VNIIOFI, Moscow. The method (and the developed facility) is based on a goniospectroradiometer system traceable to a standard Black Body and allowing the calibration of a light source in terms of TSRF and additionally providing LID data of the source.
关键词： calibration,measurement,total spectral radiant flux
更新于2025-09-23 15:21:21
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Vitamin C Determination by Ultraviolet Spectroscopy and Multiproduct Calibration
摘要： In this work the vitamin C was determined in industrialized nectar juices through ultraviolet (UV) spectroscopy and multiproduct multivariate calibration, based on partial least squares (PLS) regression. Since samples with different flavors, sugar content (light or not) were together in the model construction, it can be considered as a multiproduct and, due to the heterogeneity of the samples, it was necessary to optimize the calibration and validation sets by outliers elimination. The model was developed and validated by the evaluation of the figures of merit such as: accuracy, sensitivity, analytical sensitivity, adjust, linearity, relative prediction deviation, limits of detection and quantification, indicating that the multiproduct model developed from UV spectroscopy and PLS regression can be used in the industrial routine analysis as an alternative to titration or other time and reagent consuming methods. Here, it was evidenced that the UV-PLS multiproduct model provides advantages as being free of sample preparation steps, is suitable to be updated in order to measure other parameters, does not generates residues and is feasible to be implemented for on-line monitoring. Furthermore, the application of multivariate calibration in multiproduct models is extremely attractive from the industrial point of view.
关键词： multiproduct calibration,vitamin C,PLS,UV spectroscopy
更新于2025-09-23 15:21:21
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Analysis of alloy and solar cells with double-pulse calibration-free laser-induced breakdown spectroscopy
摘要： We applied variant of calibration free laser induced Breakdown Spectroscopy (CF-LIBS) approach for the compositional analysis of standard Gd/Ge/Si alloy and solar cells. The double pulse laser induced plasma was produced on the sample surface and the emission spectra were recorded at optimized interpulse delay and energy ratio. The Plasma temperature, determined using Boltzmann plot, was used to determine the concentration of all species present in a sample. The results are compared with reference values as well as conventional CF-LIBS results, which show that conventional and variant CF-LIBS results are similar and in close agreement to reference values. It is worth mention that the variant CF-LIBS results, but the approach is simpler and faster. Therefore, this approach was applied to three unknown polycrystalline silicon solar cells, which yield Al, C, Ca, Fe, In, Ti, Sb and Sn in the parts per million (ppm). This approach can potentially be applied for real-time trace monitoring in manufacturing processes of photovoltaic devices where conversion e?ciency depends strongly on impurities’ concentration.
关键词： Alloy and solar cells,Double pulse LIBS,Laser induced plasmas,Quantitative elemental analysis,Calibration free LIBS,Plasma parameters
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE Workshop on Power Electronics and Power Quality Applications (PEPQA) - Manizales, Colombia (2019.5.30-2019.5.31)] 2019 IEEE Workshop on Power Electronics and Power Quality Applications (PEPQA) - Determination and Performance Analysis of the Norton Equivalent Models for Fluorescents and LED Recessed Lightings
摘要： For long-wavelength space-based radars, such as the P-band radar on the recently selected European Space Agency BIOMASS mission, system distortions (crosstalk and channel imbalance), Faraday rotation, and system noise all combine to degrade the measurements. A first-order analysis of these effects on the measurements of the polarimetric scattering matrix is used to derive differentiable expressions for the errors in the polarimetric backscattering coefficients in the presence of Faraday rotation. Both the amplitudes and phases of the distortion terms are shown to be important in determining the errors and their maximum values. Exact simulations confirm the accuracy and predictions of the first-order analysis. Under an assumed power-law relation between σhv and the biomass, the system distortions and noise are converted into biomass estimation errors, and it is shown that the magnitude of the deviation of the channel imbalance from unity must be 4–5 dB less than the crosstalk, or it will dominate the error in the biomass. For uncalibrated data and midrange values of biomass, the crosstalk must be less than ?24 dB if the maximum possible error in the biomass is to be within 20% of its true value. A less stringent condition applies if the amplitudes and phases of the distortion terms are considered random since errors near the maximum possible are very unlikely. For lower values of the biomass, the noise becomes increasingly important because the σhv signal-to-noise ratio is smaller.
关键词： Biomass,Faraday rotation,polarimetric measurements,system distortion,calibration,long-wavelength radar
更新于2025-09-23 15:21:01
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[IEEE 2019 15th International Conference on Signal-Image Technology & Internet-Based Systems (SITIS) - Sorrento, Italy (2019.11.26-2019.11.29)] 2019 15th International Conference on Signal-Image Technology & Internet-Based Systems (SITIS) - Assessment of OLED Head Mounted Display for Vision Research with Virtual Reality
摘要： Vision researchers often rely on visual display technology to present observers with controlled stimuli, usually by means of a calibrated computer screen. Virtual Reality (VR) may allow a similar level of control, together with higher realism of the stimulation and a visual field larger than what is achievable on a standard computer monitor. To produce the desired the stimuli, accurate characterization of the spectral properties of the display is necessary. However, this process might not be trivial on VR displays, because 1) the Head Mounted Displays (HMD) used in VR are typically designed to be light-weight and low energy consuming, thus they might not meet some of the standard assumptions in display calibration, 2) the VR software might affect the color and luminance signal in a complex way, further complicating the calibration process. Here we show that 1) a common, off-the-shelf display used in our experiments behaves similarly to a standard OLED monitor, 2) the VR gaming engine we tested (Unreal Engine 4) introduces a complex behavior, 3) which can be disabled. This allows to accurately control colors and luminance emitted by the display, thus enabling its use for perceptual experiments.
关键词： Head Mounted Display,Color Calibration,Vision Research,Virtual Reality,OLED
更新于2025-09-23 15:21:01
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Hybrid Plasmonic Waveguide based 3??3 Multimode Interferometer for Compact 120?° Optical Hybrid
摘要： The Kinect system is arguably the most popular 3-D camera technology currently on the market. Its application domain is vast and has been deployed in scenarios where accurate geometric measurements are needed. Regarding the PrimeSense technology, a limited amount of work has been devoted to calibrating the Kinect, especially the depth data. The Kinect is, however, inevitably prone to distortions, as independently confirmed by numerous users. An effective method for improving the quality of the Kinect system is by modeling the sensor’s systematic errors using bundle adjustment. In this paper, a method for modeling the intrinsic and extrinsic parameters of the infrared and colour cameras, and more importantly the distortions in the depth image, is presented. Through an integrated marker- and feature-based self-calibration, two Kinects were calibrated. A novel approach for modeling the depth systematic errors as a function of lens distortion and relative orientation parameters is shown to be effective. The results show improvements in geometric accuracy up to 53% compared with uncalibrated point clouds captured using the popular software RGBDemo. Systematic depth discontinuities were also reduced and in the check-plane analysis the noise of the Kinect point cloud was reduced by 17%.
关键词： 3D/stereo scene analysis,quality assurance,quantization,camera calibration,Kinect
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Femtosecond-laser photoemission spectroscopy for ultrafast photovoltage dynamics: limitations and possibilities
摘要： In this paper, we study the time-of-arrival (TOA) based self-calibration problem of dual-microphone array for known and unknown rack distance, and also for different combinations of dimension for the af?ne spaces spanned by the receivers and by the senders. Particularly, we analyze the minimum cases and present minimum solvers for the case of microphones and speakers in 3-D/3-D, in 2-D/3-D, and in 3-D/2-D, with given or unknown rack length. We identify for each of these minimal problems the number of solutions in general and develop ef?cient and numerically stable, non-iterative solvers. Solving these problems are of both theoretical and practical interest. This includes understanding what the minimal problems are and how and when they can be solved. The solvers can be used to initialize local optimization algorithms for ?nding the maximum likelihood estimate of the parameters. The solvers can also be used for robust estimation of the parameters in the presence of outliers, using, e.g., RANSAC algorithms. We demonstrate that the proposed solvers are numerically stable in synthetic experiments. We also demonstrate how the solvers can be used with the RANSAC paradigm. We also apply our method for several real data experiments, using ultra-wide-band measurements and using acoustic data.
关键词： dual-microphone array,Time-of-arrival (TOA),minimal solver,self-calibration
更新于2025-09-23 15:21:01
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High-Performance Photovoltaic Hydrogen Sensing Platform with a Light-Intensity Calibration Module
摘要： Although battery-free gas sensors (e.g., photovoltaic, or triboelectric sensors) have been recently appeared to resolve the power consumption issue of conventional chemiresistors, severe technical barriers remain. Especially, their signals varying with ambient conditions such as light intensity confines the utilization of the sensors. Insufficient sensing performances (low response and slow sensing rate) of the previous battery-free sensors are also an obstacle for practical use. Herein, a photovoltaic hydrogen (H2) sensing platform having constant sensing responses regardless of light condition is demonstrated. The platform consists of two photovoltaic units: (1) a palladium (Pd)-decorated n-IGZO/p-Si photodiode covered with a microporous zeolitic imidazolate framework-8 (ZIF-8) film and (2) the same device configuration without the Pd catalyst as a reference to calibrate the base current of the sensor (1). The platform after calibration yields accurate response values in real-time regardless of unknown irradiance. Besides, the sensing performances (e.g., sensing response of 1.57 × 104% at 1% H2 with a response time < 15 s) of our platform is comparable with those of the conventional resistive H2 sensors, which are unprecedented results in photovoltaic H2 sensors.
关键词： zeolitic imidazolate framework,hydrogen sensor,battery-free gas sensor,light-intensity calibration module,photovoltaic gas sensor
更新于2025-09-23 15:21:01