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Unmanned Aerial Vehicles (UAVs) paired with image detection and segmentation techniques can be used to extract plant phenotype information of individual breeding or research plots. Each plot contains plants of a single genetic line. Breeders are interested in selecting lines with preferred phenotypes (physical traits) that increase crop yield or resilience. Automated detection and segmentation of plots would enable automatic monitoring and quantification of plot phenotypes, allowing a faster selection process that requires much fewer person-hours compared with manual assessment. A detection algorithm based on Laplacian of Gaussian (LoG) blob detection and a segmentation algorithm based on a combination of unsupervised clustering and random walker image segmentation are proposed to detect and segment lentil plots from multi-spectral aerial images. Our algorithm detects and segments lentil plots from normalized difference vegetative index (NDVI) images. The detection algorithm exhibited an average precision and recall of 96.3% and 97.2% respectively. The average Dice similarity coefficient between a detected segmented plot and its ground truth was 0.906.

A novel pulse referenced error correction method for digital PWM switching power amplifiers is proposed called pulse edge delay error correction (PEDEC). The paper presents fundamental theory for the novel control method, modeling and systematic approaches to PEDEC based digital amplifier design. The investigations are supplemented with comprehensive, low level nonlinear PSPICE based system simulation that verify the system model and furthermore illustrates the correction capability towards every error source in a switching power stage. PEDEC is the first method ever to effectively eliminate the fundamental power stage linearity problems in digital PWM power amplifier (Power DACs). The control method is concluded to be a very interesting new approach, that dramatically eases the design of high quality digital audio power amplifiers (Power DACs), since the power stage design can be relaxed and no precision A/D conversion is needed in the control system.