- 标题
- 摘要
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- 实验方案
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Optimized weighting function for IPDA lidar concerning the lower layer CO2 concentration fluctuation
摘要： Weighting function can affect the retrieval of the column gas mixing ratio of integrated path differential absorption (IPDA) lidar because it contains the vertical distribution information of the target gas. In order to optimize the wavelengths within the 1.57 um spectral band for IPDA lidar for CO2 measurement. The temperature, pressure and water vapor (TPH) sensitivity and the proportion of the weight function integration in the lower layer part to the total atmosphere layer (R) of each wavelength are calculated. The measurement errors of each wavelength are simulated with CO2 fluctuation in the lower layer. The specific wavelength with the R value of 0.6 has been found to be a stable measurement bias which does not change with fluctuations, so the R value of 0.6 is used to optimize the wavelength for measurement CO2. The simulation results show that the measurement error via wavelength is smaller than 0.05 ppm, when the TPH sensitivity is smaller than 0.95 and when R is about 0.6. This proposed method can be applicable for the further airborne or space-borne lidar development.
关键词： Column mixing ratio of CO2,Weighting function,Differential absorption lidar,IPDA
更新于2025-09-19 17:15:36
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A New Approach to H-Infinity Control for Grid-Connected Inverters in Photovoltaic Generation Systems
摘要： The present study investigates the stability problem of the grid-connected inverters (GCIs) for possible variations in grid impedance. A new type of H1 control method is proposed for the current control loop of inverters, where the third weighting function is determined using the game theory. The proposed method is applied to the GCI in a photovoltaic system and its response to variations in grid impedance is investigated. Computer simulations conducted for comparison of H1 and PI controller indicate the effectiveness of the proposed control algorithm. Simulation results also show that the proposed algorithm significantly outperforms the PI controller under the conditions of varying grid impedance.
关键词： solar energy,photovoltaic power generation,robust control,power electronics,grid-connected inverters,weighting function,game theory,H-in?nity control
更新于2025-09-11 14:15:04
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Hyperspectral image classification using a spectral–spatial random walker method
摘要： This article proposes a spectral–spatial method for classification of hyperspectral images (HSIs) by modifying traditional random walker (RW). The proposed method consists of suggesting two main modifications. First, to construct a spatial edge weighting function, low-frequency edge weighting function is proposed. In this function, the detail weights are removed. Second, to enhance the classification accuracy, a fusion of spectral and spatial Laplacian matrix in RW is suggested. This fusion can improve the classification performances compared to traditional RW using only spatial Laplacian matrix. In comparison with some of the state-of-the-art RW and spectral–spatial classifier methods, the experimental results of the proposed method (spectral–spatial RW) show that the proposed method significantly increases the classification accuracy of HSI.
关键词： spectral–spatial random walker,edge weighting function,Hyperspectral image classification,Laplacian matrix
更新于2025-09-09 09:28:46