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oe1(光电查) - 科学论文

11 条数据
?? 中文(中国)
  • [IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Validation of Wave and Wind Product of the New Phase Saral Using Buoys Data

    摘要: Since July 4th 2016, the SARAL/Altika has been moved in a new orbit, and it has continuously provided wave height measurements for more than 1 year. Before using these data, the measurements need to be validated. Based on the in-situ buoys from the National Data Buoy Center (NDBC), the SARAL Ka-band significant wave height (SWH) and Sea Surface Wind (SSW) measurements were validated and have been corrected using a linear regression with in-situ measurements. Compared with NDBC data, the validation results of SARAL show a RMS (Root Mean Square) of 0.28 m for SARAL SWH measurements and RMS of 1.30m/s for SARAL SSW speed indicating capability of AltiKa providing SWH and wind speed products with reliable accuracy. Therefore the accuracy of SARAL SWH products is higher than that of Jason-1/2 SWH data, and does not require any correction.

    关键词: Sea Surface Wind,SARAL/AltiKa,Validation,Root Mean Square,Significant Wave Height

    更新于2025-09-23 15:22:29

  • [IEEE 2018 37th Chinese Control Conference (CCC) - Wuhan (2018.7.25-2018.7.27)] 2018 37th Chinese Control Conference (CCC) - On-line Detection and Analysis of Alloy Steel Elements Based on the LIBS Technology and Random Forest Regression

    摘要: The Laser Induced Breakdown Spectroscopy (LIBS) technology can be used to detect the elements in the alloy steel in real time. Quantitative analysis method of the traditional LIBS technology mainly has the calibration method and calibration free method, but there are two shortcomings: low prediction accuracy and over fitting. Random Forest Regression (RFR) algorithm can be used for classification and regression, can effectively avoid 'overfitting' phenomenon. Therefore, in this paper, we combine the random forest regression algorithm with laser induced breakdown spectroscopy applied to the detection of the concentration of alloy steel elements in the metallurgy industry. At the same time, compared with partial least squares method based on the LIBS, the results show that the random forest algorithm combined with the LIBS technology has the higher prediction accuracy, lower root mean square error and better robustness.

    关键词: PLS,root mean square error,quantitative analysis,LIBS,RFR

    更新于2025-09-23 15:22:29

  • On the root mean square error (RMSE) calculation for parameter estimation of photovoltaic models: A novel exact analytical solution based on Lambert W function

    摘要: In the literature, one can find a lot of methods and techniques employed to estimate single diode solar photovoltaic (PV) cell parameters. The efficiency of these methods is usually tested by calculating the Root Mean Square Error (RMSE) between the measured and estimated values of the solar PV cell output current. In this work, first, the values of RMSE calculated using 69 different methods published in many journal papers for the well-known RTC France solar PV cell are presented and discussed. Second, a novel exact analytical solution for RMSE calculation based on the Lambert W function is proposed. The results obtained show that the RMSE values were not calculated correctly in most of the methods presented in the literature since the exact expression of the calculated cell output current was not used. Third, the precision of calculation of the methods used for analytical solving of Lambert W equation is presented and discussed. Fourth, the applicability of the proposed solution methodology in accordance with current-voltage characteristics measured in the laboratory for solar modules of Clean Energy Trainer Setup is checked. Identification of its unknown parameters is presented using three optimization techniques. Further, the proposed solution methodology is proven for Solarex MSX–60 PV module, and the most promising 5-parameter single diode parameters are estimated based on minimization of the precise RMSE values calculated. Finally, this work aimed to develop a good base for proper investigation and implementation of optimization algorithms to solve the parameter estimation problem of 5-parameter single diode PV equivalent circuits.

    关键词: Root mean square error,5-parameter single diode model,PV parameter estimation,Optimization,RTC France solar cell,Lambert W function

    更新于2025-09-23 15:21:01

  • [IEEE 2019 IEEE 13th International Conference on Compatibility, Power Electronics and Power Engineering (CPE-POWERENG) - Sonderborg, Denmark (2019.4.23-2019.4.25)] 2019 IEEE 13th International Conference on Compatibility, Power Electronics and Power Engineering (CPE-POWERENG) - An AN-GA Controlled SEPIC Converter for Photovoltaic Grid Integration

    摘要: In this paper, Artificial Neural Network (ANN) optimization with Genetic Algorithm (GA) is implemented. The optimized training to ANN is provide using Bayesian regulation. For this study, a Photovoltaic (PV) system has considered and optimal power tracking been interpreted with proper adjustment of ANN weights using GA approach, which reduces the Root Mean Square Error (RMSE). In this work, the single-ended primary – inductor converter (SEPIC) has been utilized for better power tracking from PV modules. SEPIC Converter accomplish with impedance matching power device and provides utmost PV power tracking. Space vector pulse width modulation-dSPACE interface been utilized as an inverter control. Simulated responses show the potency of the proposed system under sag, swell and varying loading conditions.

    关键词: Root Mean Square Error (RMSE),SEPIC.,Grid,Photovoltaic,Artificial neural network (ANN),Genetic Algorithm (GA)

    更新于2025-09-19 17:13:59

  • [IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Thinking Beyond Limiting Efficiencies Of Advanced Concepts: Design Rules And Material Requirements For Realistic Devices

    摘要: The current-fed dual active bridge (CF-DAB) dc–dc converter gains growing applications in photovoltaic (PV) and energy storage systems due to its advantages, e.g., a wide input voltage range, a high step-up ratio, a low input current ripple, and a multiport interface capability. In addition, the direct input current controllability and extra control freedom of the CF-DAB converter make it possible to buffer the double-line-frequency energy in grid-interactive PV systems without using electrolytic capacitors in the dc link. Therefore, a PV system achieves high reliability and highly ef?cient maximum power point tracking. This paper studies the optimized operation of a CF-DAB converter for a PV application in order to improve the system ef?ciency. The operating principle and soft-switching conditions over the wide operating range are thoroughly analyzed with phase-shift control and duty-cycle control, and an optimized operating mode is proposed to achieve the minimum root-mean-square transformer current. The proposed operating mode can extend the soft-switching region and reduce the power loss, particularly under a heavy load and a high input voltage. Moreover, the ef?ciency can be further improved with a higher dc-link voltage. A 5-kW hardware prototype was built in the laboratory, and experimental results are provided for veri?cation. This paper provides a design guideline for the CF-DAB converter applied to PV systems, as well as other applications with a wide input voltage variation.

    关键词: root-mean-square (RMS) current,photovoltaic (PV),soft switching,optimized operation,Current-fed dual active bridge (CF-DAB)

    更新于2025-09-19 17:13:59

  • Forecasting the Performance of a Photovoltaic Solar System Installed in other Locations using Artificial Neural Networks

    摘要: Photovoltaic solar energy has been spread all over the world, and in Brazil this energy source has been getting considerable space in the last years, being driven mainly by the energy crises. However, when installed in regions with low incidence of solar irradiation, this technology presents a loss of efficiency in the generation of energy. As an alternative to this consideration, a power prediction study could be conducted prior to its installation, based on local climate information that directly influences power generation, verifying the feasibility of system implementation and avoiding unrewarded investment. Therefore, the objective of this work is to predict the viability of the installation of a photovoltaic system of 3kWp in different places, with the assist of an Artificial Neural Network. Thus, the feedforward network was used for the training, being trained and validated with the support of MatlabVR , and inserting samples of temperature and solar irradiation as input variables. Through the performance methods, the results are favorable for this application, presenting validations with RMSE% in the range of 13-20% and R of not less than 0.93. The predictions presented RMSE% around 19-25% and average powers close to the real values generated by the PV system.

    关键词: solar irradiation,renewable energy,electrical systems,energy efficiency,power forecasting,feedforward,artificial neural network,root mean square error,solar photovoltaic system,distributed generation

    更新于2025-09-19 17:13:59

  • [IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Validation of Advanced Photovoltaic Module Materials and Processes by Combined-Accelerated Stress Testing (C-AST)

    摘要: The current-fed dual active bridge (CF-DAB) dc–dc converter gains growing applications in photovoltaic (PV) and energy storage systems due to its advantages, e.g., a wide input voltage range, a high step-up ratio, a low input current ripple, and a multiport interface capability. In addition, the direct input current controllability and extra control freedom of the CF-DAB converter make it possible to buffer the double-line-frequency energy in grid-interactive PV systems without using electrolytic capacitors in the dc link. Therefore, a PV system achieves high reliability and highly ef?cient maximum power point tracking. This paper studies the optimized operation of a CF-DAB converter for a PV application in order to improve the system ef?ciency. The operating principle and soft-switching conditions over the wide operating range are thoroughly analyzed with phase-shift control and duty-cycle control, and an optimized operating mode is proposed to achieve the minimum root-mean-square transformer current. The proposed operating mode can extend the soft-switching region and reduce the power loss, particularly under a heavy load and a high input voltage. Moreover, the ef?ciency can be further improved with a higher dc-link voltage. A 5-kW hardware prototype was built in the laboratory, and experimental results are provided for veri?cation. This paper provides a design guideline for the CF-DAB converter applied to PV systems, as well as other applications with a wide input voltage variation.

    关键词: soft switching,optimized operation,Current-fed dual active bridge (CF-DAB),photovoltaic (PV),root-mean-square (RMS) current

    更新于2025-09-19 17:13:59

  • Directional Beam Based LED Deployment for a Short Range Indoor LED Light Communication System

    摘要: There is now an increasing awareness about the possibility of health hazards due to excessive electromagnetic radiations around us within the indoor environment. Hence, the alternative communication technologies such as indoor mobile communication system based on LED lighting are gaining more attention in the present scenario. The dual use of LEDs i. e. for illumination as well as for setting up of an indoor communication network infrastructure simultaneously makes it an attractive preposition. The LED lighting based communication system is qualified to be part of green technology networks. This paper investigates the optimal LED placement strategy for such a system to optimize the overall communication system parameters including the transmit power optimization. It is observed that the overall optimization of LEDs improve the signal to noise ratio and also a significant reduction in root mean square delay at lower semi-angle values besides improving the mobile coverage area.

    关键词: root mean square delay,LED lighting based communication system,mobility,communication coverage area,signal to noise ratio

    更新于2025-09-16 10:30:52

  • Laser Doppler Signal Denoising Based on Wavelet Packet Thresholding Method

    摘要: In laser Doppler velocimeter (LDV), calculation precision of Doppler shift is affected by noise contained in Doppler signal. In order to restrain the noise interference and improve the precision of signal processing, wavelet packet threshold denoising methods are proposed. Based on the analysis of Doppler signal, appropriate threshold function and decomposition layer number are selected. Heursure, sqtwolog, rigrsure, and minimaxi rules are adopted to get the thresholds. Processing results indicate that signal-to-noise ratio (SNR) and root mean square error (RMSE) of simulated signals with original SNR of 0 dB, 5 dB, and 10 dB in both low- and high-frequency ranges are significantly improved by wavelet packet threshold denoising. A double-beam and double-scattering LDV system is built in our laboratory. For measured signals obtained from the experimental system, the minimum relative error of denoised signal is only 0.079% (using minimaxi rule). The denoised waveforms of simulated and experimental signals are much more smooth and clear than that of original signals. Generally speaking, denoising effects of minimaxi and saqtwolog rules are better than those of heursure and rigrsure rules. As shown in the processing and analysis of simulated and experimental signals, denoising methods based on wavelet packet threshold have ability to depress the noise in laser Doppler signal and improve the precision of signal processing. Owing to its effectiveness and practicability, wavelet packet threshold denoising is a practical method for LDV signal processing.

    关键词: wavelet packet threshold denoising,laser Doppler velocimeter,signal-to-noise ratio,double-beam and double-scattering LDV system,root mean square error

    更新于2025-09-16 10:30:52

  • [IEEE 2019 IEEE Industry Applications Society Annual Meeting - Baltimore, MD, USA (2019.9.29-2019.10.3)] 2019 IEEE Industry Applications Society Annual Meeting - LED Power Factor and Quality Factor

    摘要: This paper presents the LED power factor and quality factor simply characterized from the available terminal average current, average voltage, and RMS current to evaluate the electric power quality of LEDs. The LED average power is composed of the bandgap power and the resistive power due to the forward voltage and equivalent series resistor in the LED approximate linear circuit, respectively. The forward voltage and equivalent series resistor are characterized from the available terminal average current, average voltage, and RMS current to calculate the bandgap power and the resistive power. The LED power factor and quality factor are calculated from the bandgap power, resistive power and average power to evaluate the electric power quality of LEDs. Using a single-branch LED approximate linear circuit and a high-order LED piece-wise linear circuit, two verification examples, respectively, are demonstrated to calculate their LED power factor and quality factor.

    关键词: light-emitting-diode,average power,root-mean-square,average current,forward voltage,resistive power,bandgap power,power factor,rms,LED,quality factor

    更新于2025-09-16 10:30:52