RESUMEN
In this paper, we make full advantage of the information correlation of subaperture images and propose a new super-resolution (SR) reconstruction method based on spatiotemporal correlation to achieve SR reconstruction for light-field images. Meanwhile, the offset compensation method based on optical flow and spatial transformer network is designed to realize accurate compensation between adjacent light-field subaperture images. After that, the obtained light-field images with high resolution are combined with the self-designed system based on phase similarity and SR reconstruction to realize accurate 3D reconstruction of a structured light field. Finally, experimental results demonstrate the validity of the proposed method to perform accurate 3D reconstruction of light-field images from the SR data. Generally, our method makes full use of the redundant information between different subaperture images, hides the upsampling process in the convolution, provides more sufficient information, and reduces time-consuming procedures, which is more efficient to realize the accurate 3D reconstruction of light-field images.
RESUMEN
Air concentrations of volatile organic compounds (VOCs) were continually measured at a monitoring site in Shenyang from 20 August to 16 September 2017. The average concentrations of alkanes, alkenes, aromatics and carbonyls were 28.54, 6.30, 5.59 and 9.78 ppbv, respectively. Seven sources were identified by the Positive Matrix Factorization model based on the measurement data of VOCs and CO. Vehicle exhaust contributed the most (36.15%) to the total propene-equivalent concentration of the measured VOCs, followed by combustion emission (16.92%), vegetation emission and secondary formation (14.33%), solvent usage (10.59%), petrochemical industry emission (9.89%), petrol evaporation (6.28%), and liquefied petroleum gas (LPG) usage (5.84%). Vehicle exhaust, solvent usage and combustion emission were found to be the top three VOC sources for O3 formation potential, accounting for 34.52%, 16.55% and 11.94%, respectively. The diurnal variation of the total VOCs from each source could be well explained by their emission characteristics, e.g., the two peaks of VOC concentrations from LPG usage were in line with the cooking times for breakfast and lunch. Wind rose plots of the VOCs from each source could reveal the possible distribution of the sources around the monitoring site. The O3 pollution episodes during the measurement period were found to be coincident with the elevation of VOCs, which was mainly due to the air parcel from the southeast direction where petrochemical industry emission was found to be dominant, suggesting that the petrochemical industry emission from the southeast was probably a significant cause of O3 pollution in Shenyang.