Fig. 7: sandID image-analysis results.
From: Fingerprinting construction sand-supply networks for traceable sourcing
a All sand samples (all material <2 mm) and b all samples sieved at 500 microns (medium sand and finer). For both a and b, the scatter plot is a two-dimensional, simplified representation of what the neural network “sees” as differences between each source population in images using t-Distributed Stochastic Neighbor Embedding (tsne) to squeeze 1024 identified features into 2-D representations that can be assessed visually. Each color-coded point is a snip of a training image and distance between two points roughly correlates to degree of difference. In both a and b, the confusion matrix illustrates model success in assigning an image of sand to its correct original source. low. CR samples derived from the lower Colorado River (east Houston bagged-concrete), Hol. uCR samples derived from Holocene terraces of the upper Colorado River, Pleis. uCR samples derived from Pleistocene terraces of the upper Colorado River. SA bag conc.: San Antonio bagged concrete, SA m&bp: samples from San Antonio mines and concrete batch plants.
