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- IoT based data acquisition system
- Grid tie solar PV system
- IoT
- Losses in Solar PV plant
- Raspberry Pi
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- Electrical Engineering and Automation
- Zeal College of Engineering and Research
- Kuban State Agrarian University
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PeQASO: Perceptual Quality Assessment of Streamed Videos Using Optical Flow Features
摘要： In this paper, we introduce PeQASO, a perceptual quality assessment framework for streamed videos using optical ?ow features. This approach is a reduced-reference pixel-based and relies only on the deviation of the optical ?ow of the corrupted frames. This technique compares an optical ?ow descriptor from the received frame against the descriptor obtained from the anchor frame. This approach is suitable for videos with complex motion patterns. Our technique does not make any assumptions on the coding conditions, network loss patterns or error concealment techniques. In this paper, we consider both sources of artifacts and distortions in streaming, including compression artifacts. We validate our proposed metric by testing it on a variety of distorted sequences from three proposed and commonly utilized video quality assessment databases. Our results show that our metric estimates the perceptual quality at the sequence level accurately. We report the correlation coef?cients with the differential mean opinion scores reported in the database. For compression artifacts, the results show Spearman’s and Pearson’s correlations of 0.96 and 0.94 for all the tested sequences, respectively. For channel-induced distortion, the results show Spearman’s and Pearson’s correlations of 0.88 and 0.89, respectively. For all other distortions, the average Spearman’s and Pearson’s correlations are 0.82 and 0.79, respectively.
关键词： Video quality assessment,optical ?ow,video streaming,video coding,channel losses,video quality monitoring,video distortion
更新于2025-09-09 09:28:46
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Characterization of Evanescent Field Gas Sensor Structures Based on Silicon Photonics
摘要： Photonic sensors that operate in the mid-infrared spectral range are an emerging field for photonic microsystems. In this paper, we present a photonic gas sensor concept based on silicon waveguides using infrared evanescent field absorption. The waveguides were specifically designed for CO2 sensing at a wavelength of λ = 4.26 μm as possible application for the proposed sensor platform. The waveguide cross section as well as the substructure were investigated using finite-element simulations and the devised structures were fabricated using mass fabrication processes exclusively. In order to evaluate the potential for long interaction path lengths using polysilicon strip waveguides, a study on the intrinsic losses of polysilicon waveguides was conducted. The lowest intrinsic damping that was obtained for polysilicon strip waveguides was 3.98 dB/cm. Furthermore, the sensing capability of the devised waveguides was tested with quantitative CO2 measurements down to a concentration of 500 ppm CO2. From the quantitative measurements, the evanescent field ratio was estimated and was in the range between η = 14%–16%.
关键词： integrated silicon photonics,intrinsic losses,evanescent field absorption,silicon waveguide,Optical gas sensing
更新于2025-09-09 09:28:46
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Symmetric surface complex waves in Goubau Line
摘要： Existence of symmetric surface complex waves in a Goubau line—a perfectly conducting cylinder of circular cross-section covered by a concentric dielectric layer—is proved by constructing perturbation of the spectrum of symmetric real waves with respect to the imaginary part of the permittivity of the dielectric cover. Closed-form iteration procedures for calculating the roots of the dispersion equation (DE) in the complex domain supplied with efficient choice of initial approximation are developed. Numerical modeling is performed with the help of a parameter-differentiation method applied to the analytical and numerical solution of DEs.
关键词： dispersion equation,attenuation,losses,Goubau line,complex surface wave
更新于2025-09-04 15:30:14
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[IEEE 2018 7th International Conference on Renewable Energy Research and Applications (ICRERA) - Paris, France (2018.10.14-2018.10.17)] 2018 7th International Conference on Renewable Energy Research and Applications (ICRERA) - Application of Model Predictive Control in Modular Multilevel Converters for MTPA Operation and reduced Switching Losses
摘要： In this paper, a one-step Model Predictive Control system is executed in the Multilevel modular converter (MMC) to control the speed of an Interior Permanent Magnet (IPM) machine. Maximum Torque per Ampere (MTPA) and Field Weakening (FW) control technique is utilized for the greatest yield torque. The proposed Control strategy tracks the reference produced by MTPA and FW calculation by freely directing voltages from the MMC modules. The proposed method also studies the relation between the switching losses of MOSFETs and sampling frequency, cost function and a number of modules in an MMC. Finally, simulation results are provided to demonstrate the appropriateness of this control procedure.
关键词： Model Predictive Control,Modular Multilevel Converter (MPC),Maximum Torque per Ampere (MTPA),Interior Permanent Magnet motor (IPM),Switching losses,Field Weakening (FW)
更新于2025-09-04 15:30:14
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[IEEE 2018 IEEE 6th Workshop on Wide Bandgap Power Devices and Applications (WiPDA) - Atlanta, GA, USA (2018.10.31-2018.11.2)] 2018 IEEE 6th Workshop on Wide Bandgap Power Devices and Applications (WiPDA) - Substrate Bias Effect on E-Mode GaN-on-Si HEMT Cos<inf>s</inf> Losses
摘要： Previous work found large COSS losses in GaN-on-Si HEMTs used in soft-switched, MHz-frequency power converters. Here, we use a back-gate bias between the source and Si substrate to investigate the capacitance characteristics of commercially-available GaN HEMTs. The small-signal capacitance is reduced significantly – up to 2× for a 650 V HEMT and 4× for a 100 V HEMT – indicating that the drain-substrate capacitance is a significant portion of the total output capacitance. This portion of the capacitance appears responsible for trapping-detrapping with time constants on the order of seconds. We verify this by testing the 100 V GaN HEMT in the Sawyer-Tower circuit with negative substrate bias, finding that COSS losses are reduced by up to 30% compared to the shorted substrate condition.
关键词： Sawyer-Tower circuit,COSS losses,capacitance characteristics,GaN-on-Si HEMTs,substrate bias
更新于2025-09-04 15:30:14