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- 2018
- imgae sensor
- internet of things
- drone
- visible light ID
- Signal-to-Noise Ratio (SNR)
- Infinite Gain Multiple Feedback (IGMF)
- Visible Light Communications (VLC)
- LED
- Trans-Impedance Amplifier (TIA)
- Optoelectronic Information Science and Engineering
- Tohoku University
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VALIDATED SPECTROPHOTOMETRIC METHOD FOR THE ESTIMATION OF VINCRISTINE AND VINBLASTINE
摘要： Objective: A simple, sensitive, precise, reproducible and validated UV spectrophotometric methods have been developed for the determination of vincristine (VCR) and vinblastine (VLB) in the pure and dosage forms. Methods: The method was founded on the simple solubility of VCR and VLB in purified water, and their characteristic maximum absorption λ (max) at 295 nm and λ (max) at 268 nm for VCR and VLB respectively in the UV regions. The nature of obedience, to the Bouguer-Lambert-Beer’s law by the VCR and VLB in the range of concentration 5-50 μg/ml was employed to this method. Results: Accuracy and reproducibility of the proposed method were statistically validated by recovery studies. The accuracy of the method for the VCR and VLB was ~ 100.4 % and ~ 100.32 % respectively with good reproducibility. The analytical curves were linear over a wide concentration range (5-50 μg/ml), with a correlation coefficient (r)-0.9998, and 0.9999 for VCR and VLB in that order. The method was showed sufficient precision, with a relative standard deviation (RSD) less than 1%. Conclusion: The method was validated in accordance with Russian general pharmacopoeia article (RGPA) 42-0113-09 and ICH guidelines. Validated method can easily apply for fast, precise and reliable rapid assessment of drug forms and pure substances in the laboratory.
关键词： Vincristine,Quantity determination,Analytical curve,Vinblastine,UV-visible spectrometry
更新于2025-09-23 15:22:29
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[IEEE 2018 International Conference of the Biometrics Special Interest Group (BIOSIG) - Darmstadt (2018.9.26-2018.9.28)] 2018 International Conference of the Biometrics Special Interest Group (BIOSIG) - A benchmark database of visible and thermal paired face images across multiple variations
摘要： Although visible face recognition systems have grown as a major area of research, they are still facing serious challenges when operating in uncontrolled environments. In attempt to overcome these limitations, thermal imagery has been investigated as a promising direction to extend face recognition technology. However, the reduced number of databases acquired in thermal spectrum limits its exploration. In this paper, we introduce a database of face images acquired simultaneously in visible and thermal spectra under various variations: illumination, expression, pose and occlusion. Then, we present a comparative study of face recognition performances on both modalities against each variation and the impact of bimodal fusion. We prove that thermal spectrum rivals with the visible spectrum not only in the presence of illumination changes, but also in case of expression and poses changes.
关键词： visible spectrum,thermal spectrum,pose,score-level fusion,sensor-level fusion,occlusion,expression,illumination,face database
更新于2025-09-23 15:22:29
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AgCl/Ag/LaFeO3 heterojunction with a prolonged charge lifetime and enhanced visible light catalytic property
摘要： In this study, uniform mesoporous three–dimensional LaFeO3 with diameter of 2–3 μm was prepared by a hydrothermal process and monodispersed AgCl was then decorated on the surface of the LaFeO3 to form AgCl/Ag/LaFeO3 heterojunction via a facile precipitation–deposition process. The e?ects of the proportions employed in the preparation of the heterojunction on the structural, crystallinity, surface areas, and optical properties of AgCl/Ag/LaFeO3 were systematically studied, which showed that the AgCl/Ag/LaFeO3 heterojunction had a strong hybrid–junction structure, suitable absorption edge, and many exposed surface sites. The AgCl/Ag/LaFeO3 heterojunction had a strong catalytic activity during the degradation of methylene blue and phenol under visible light. The results demonstrated that the AgCl/Ag/LaFeO3 heterojunction had a more intense photocurrent response and smaller surface resistance than both AgCl and LaFeO3. The enhanced photocatalytic ability was attributed to the formation of heterojunctions between AgCl and LaFeO3, which suppressed the recombination of photogenerated electron–hole pairs. Our results may facilitate the rational design of highly e?cient heterogeneous heterojunctions for the removal of organic pollution.
关键词： AgCl/Ag/LaFeO3,Hybrid–junction structure,Charge transfer property,Visible light
更新于2025-09-23 15:22:29
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Simultaneous quantitative analysis of indomethacin and benzoic acid in gel using ultra-violet-visible spectrophotometry and chemometrics
摘要： BACKGROUND: In order to manufacture pharmaceutical products, real-time monitoring in the manufacturing process is necessary, but large equipment cost is required to achieve it. OBJECTIVE: The aim of this research is to use ultra-violet-visible spectroscopy along with chemometrics procedure to simultaneously quantitative analysis of indomethacin (IMC) and benzoic acid (BA) in the gel during pharmaceutical manufacturing process. METHODS: The gel preparations were contained of 0.1–1.5% IMC, 0.015–0.225% BA, 2% carbopol? 941 and 95% ethanol solution. The calibration models were constructed using the partial least square regression (PLS). RESULTS: The relationships of the measured and predicted concentrations for both IMC and BA had linear plots. The developed PLS calibration models were used to monitor the IMC and BA concentrations during mixing of the gels by the planetary centrifugal and conventional mixers, respectively. IMC and BA were gradually dispersed, dissolved and completely homogeneous within 30 min by the centrifugal mixer. In contrast, IMC and BA were slowly dispersed, dissolved and completely homogeneous at more than 60 min by the conventional mixer. CONCLUSIONS: The ultra-violet-visible spectrophotometric method couples with multivariate chemometric techniques for quantitative data analysis were successfully applied for the simultaneous determination of major component IMC and trace component BA in the gel.
关键词： benzoic acid,indomethacin,partial least square regression,Ultra-violet-visible spectroscopy,process analysis technology,process monitoring
更新于2025-09-23 15:22:29
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A Simple Route in Fabricating Carbon-Modified Titania Films with Glucose and Their Visible-Light-Responsive Photocatalytic Activity
摘要： Carbon-modi?ed titania (C–TiO2) ?lms were easily prepared by using an impregnation process with a glucose-containing TiO2 sol. Through controlling calcination conditions, the as-obtained C–TiO2 products exhibited highly photocatalytic activity for the degradation of gaseous NOx under visible light and ultraviolet illumination. The effects of carbon content and calcination temperature on the photocatalytic performances and their photochemical and physical properties were investigated. Carbonaceous species on the TiO2 surface enhanced the visible-light absorption of TiO2 ?lms; however, an excessive amount of carbon on the TiO2 surface reduced its photocatalytic ability due to the serious coverage effect on active sites. The results show that a suitable glucose addition is about 50–100% of the weight of TiO2 content and the optimized calcination temperature is 300 ?C, which leads to better photocatalytic activity under ultraviolet and visible- light irradiations. Accordingly, the simple-prepared C–TiO2 ?lms functioned as visible-light-responsive catalysts, allowing for a feasible producing route for real applications.
关键词： glucose,titania ?lm,impregnation,carbon-modi?ed,visible-light-responsive
更新于2025-09-23 15:22:29
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Determination of Pigments in Virgin and Extra-Virgin Olive Oils: A Comparison between Two Near UV-Vis Spectroscopic Techniques
摘要： The colour of olive oil is due to the presence of natural pigments belonging to the class of carotenoids, chlorophylls, and their derivatives. These substances, other than being responsible for the colour, an important qualitative feature of the oil, have antioxidant and, more generally, nutraceutical properties and their quantification can be related to the product’s quality and authenticity. In this work, we have quantified the total amount of carotenoids and chlorophylls’ derivatives in several virgin and extra-virgin olive oils produced in Italy, by using two different methods that are based on near-ultraviolet-visible absorption spectroscopy. The first method defines two indexes, K670 and K470, related to absorbance values of oil at wavelengths of 670 and 470 nm, respectively. The second method is based on the mathematical deconvolution of the whole absorption spectrum of the oil to obtain the concentrations of four main pigments present in olive oils: β-carotene, lutein, pheophytin A, and pheophytin B. The concentrations of the total carotenoids and total chlorophylls’ derivatives, as obtained by the two spectroscopic methods, are compared and the results are discussed in view of the practical usefulness of spectroscopic techniques for a fast determination of pigments in olive oil.
关键词： EVOO,colour,ultraviolet-visible light,extra-virgin olive oil,chlorophylls,pigments,carotenoids,spectroscopy,quality,light absorption
更新于2025-09-23 15:22:29
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Stability Monitoring of the VIIRS Day/Night Band over Dome C with a Lunar Irradiance Model and BRDF Correction
摘要： The unique feature of the Visible Infrared Imager Radiometer Suite (VIIRS) day/night band (DNB) is its ability to take quantitative measurements of low-light scenes at night. In order to monitor the stability of the high gain stage (HGS) of the DNB, nighttime observations over the Dome C site under moonlight are analyzed in this study. The Miller and Turner 2009 (MT2009) lunar irradiance model has been used to simulate lunar illumination over Dome C. However, the MT2009 model does not differentiate the waxing and waning lunar phases. In this paper, the MT-SWC (SeaWiFS Corrected) lunar irradiance model differentiating the waxing and waning lunar phases is derived by correcting the MT2009 model using lunar observations made by the Sea-Viewing Wide Field-of-View Sensor (SeaWiFS). In addition, a top of atmosphere (TOA) bi-directional reflectance distribution function (BRDF) model during nighttime over Dome C is developed to remove the angular dependence from the nighttime TOA reflectance. The long-term stability monitoring of the DNB high-gain stage (HGS) reveals a lower reflectance factor in 2012 in comparison to the following years, which can be traced back to the change in relative spectral response (RSR) of National Oceanic & Atmospheric Administration's (NOAA's) Interface Data Processing Segment (IDPS) VIIRS DNB in April 2013. It also shows the radiometric stability of DNB data, with long-term stability of less than 1.58% over the periods from 2013 to 2016. This method can be used to monitor the radiometric stability of other low-light observing sensors using vicarious calibration sites under moonlight illumination.
关键词： visible infrared imaging radiometer suite (VIIRS),Miller and Turner 2009 (MT2009),Sea-Viewing Wide Field-of-View Sensor (SeaWiFS),Dome C site,day/night band (DNB),lunar observations,BRDF effect
更新于2025-09-23 15:22:29
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Consistent Calibration of VIRR Reflective Solar Channels Onboard FY-3A, FY-3B, and FY-3C Using a Multisite Calibration Method
摘要： The FengYun-3 (FY-3) Visible Infrared Radiometer (VIRR), along with its predecessor, the Multispectral Visible Infrared Scanning Radiometer (MVISR), onboard the FY-1C and FY-1D, has collected continuous daily global observations for 18 years. Achieving accurate and consistent calibration for VIRR reflective solar bands (RSBs) has been challenging, as there is no onboard calibrator and the frequency of in situ vicarious calibration is limited. In this study, a new set of reflectance calibration coefficients were derived for RSBs of the FY-3A, FY-3B, and FY-3C VIRRs using a multisite (MST) calibration method. This method is an extension of a previous MST calibration method, which relies on radiative transfer modeling over the multiple stable earth sites, and no synchronous in situ measurements are needed; hence, it can be used to update the VIRR calibration on a daily basis. The on-orbit radiometric changes of the VIRR onboard the FY-3 series were assessed based on analyses of new sets of calibration slopes. Then, all recalibrated VIRR reflectance data over Libya 4, the most frequently used stable Earth site, were compared with those provided from the Level 1B (L1B) product. Additional validation was performed by comparing the recalibrated VIRR data with those derived from radiative transfer simulations using measurements from automatic calibration instruments in Dunhuang. The results indicate that the radiometric response changes of the VIRRs onboard FY-3A and FY-3B were larger than those of FY-3C VIRR and were wavelength dependent. The current approach can provide consistent VIRR reflectances across different FY-3 satellite platforms. After recalibration, differences in top-of-atmosphere (TOA) reflectance data across different VIRRs during the whole lifetime decreased from 5–10% to less than 3%. The comparison with the automatic calibration method indicates that MST calibration shows good accuracy and lower temporal oscillations.
关键词： calibration,FengYun-3,reflective solar bands (RSBs),stable Earth site,Visible and Infrared Radiometer (VIRR)
更新于2025-09-23 15:22:29
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An Effective Palmprint Recognition Approach for Visible and Multispectral Sensor Images
摘要： Among several palmprint feature extraction methods the HOG-based method is attractive and performs well against changes in illumination and shadowing of palmprint images. However, it still lacks the robustness to extract the palmprint features at different rotation angles. To solve this problem, this paper presents a hybrid feature extraction method, named HOG-SGF that combines the histogram of oriented gradients (HOG) with a steerable Gaussian filter (SGF) to develop an effective palmprint recognition approach. The approach starts by processing all palmprint images by David Zhang’s method to segment only the region of interests. Next, we extracted palmprint features based on the hybrid HOG-SGF feature extraction method. Then, an optimized auto-encoder (AE) was utilized to reduce the dimensionality of the extracted features. Finally, a fast and robust regularized extreme learning machine (RELM) was applied for the classification task. In the evaluation phase of the proposed approach, a number of experiments were conducted on three publicly available palmprint databases, namely MS-PolyU of multispectral palmprint images and CASIA and Tongji of contactless palmprint images. Experimentally, the results reveal that the proposed approach outperforms the existing state-of-the-art approaches even when a small number of training samples are used.
关键词： auto-encoder,regularized extreme learning machine,security,HOG-SGF feature extraction,visible and multispectral palmprint images
更新于2025-09-23 15:22:29
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VLC and D2D Heterogeneous Network Optimization: A Reinforcement Learning Approach Based on Equilibrium Problems with Equilibrium Constraints
摘要： The Radio Frequency (RF) spectrum crunch has triggered the harnessing of other sources of bandwidth, for which visible light is a promising candidate. Even though Visible Light Communication (VLC) ensures high capacity, coverage is limited. This necessitates the integration of VLC and Device-to-Device (D2D) technologies into heterogeneous networks. In particular, mobile users which are accessible by the VLC transmitters can relay data to mobile users which are not, by means of D2D communication. However, due to the distributed behaviors of mobile users, determining optimal data transmission routes from VLC transmitters to end mobile devices is a major challenge. In this paper, we propose a Reinforcement Learning (RL) based approach to determine multi-hop data transmission routes in an indoor VLC-D2D heterogeneous network. We obtain the rewards for the RL based method dynamically, by formulating the interactions between the mobile users relaying the data as an Equilibrium Problem with Equilibrium Constraints (EPEC) and using Alternating Direction Method of Multipliers (ADMM) to solve it. The proposed technique can achieve optimal data transmission routes in a distributed manner. Simulation results demonstrate the effectiveness of the proposed approach, showing that transmission routes with low delays and high capacities can be achieved through the learning algorithm.
关键词： Device-to-Device,Reinforcement Learning,Visible Light Communication,Alternating Direction Method of Multipliers,Heterogeneous Network,Equilibrium Problem with Equilibrium Constraints
更新于2025-09-23 15:22:29