Polarimetric SAR Image Supervised Classification Method Integrating Eigenvalues

Since classification methods based on H/α space have the drawback of yielding poor classification results for terrains with similar scattering features, in this study, we propose a polarimetric Synthetic Aperture Radar (SAR) image classification method based on eigenvalues. First, we extract eigenvalues and fit their distribution with an adaptive Gaussian mixture model. Then, using the naive Bayesian classifier, we obtain preliminary classification results. The distribution of eigenvalues in two kinds of terrains may be similar, leading to incorrect classification in the preliminary step. So, we calculate the similarity of every terrain pair, and add them to the similarity table if their similarity is greater than a given threshold. We then apply the Wishart distance-based KNN classifier to these similar pairs to obtain further classification results. We used the proposed method on both airborne and spaceborne SAR datasets, and the results show that our method can overcome the shortcoming of the H/α-based unsupervised classification method for eigenvalues usage, and produces comparable results with the Support Vector Machine (SVM)-based classification method

Effect of surfactant on bound water content and extracellular polymers substances distribution in sludge

In this study, the effect of surfactant conditioning on bound water and extracellular polymers substances (EPS) in sludge was investigated. Results showed that by adding dodecyl dimethyl benzyl ammonium chloride (DDBAC), loosely bound EPS (LB-EPS) and slime layer EPS (S-EPS) contentswere increased, while tightly bound EPS (TB-EPS) and bound water contents (W-B) were reduced. As a result, the dewatering performance of sludge was enhanced. When 75 mg g(-1) of DDBAC were added, W-B in sludge decreased to 1.64 g g(-1), and the water content of dewatered sludge (W-C) dropped to 66.61%. EPS partially hydrolyzed into small molecular organics under DDBAC conditioning. Moreover, the quantity and species of organic functional groups in S-EPS were increased obviously. The TB-EPS content accounted for the majority of EPS in sludge, and the protein and polysaccharide in TB-EPS had a significant positive correlation with bound water, which was the main factor affecting W-B in sludge