Extraction of informative regions of a face for facial expression recognition

The aim of facial expression recognition (FER) algorithms is to extract discriminative features of a face. However, discriminative features for FER can only be obtained from the informative regions of a face. Also, each of the facial subregions have different impacts on different facial expressions. Local binary pattern (LBP) based FER techniques extract texture features from all the regions of a face, and subsequently the features are stacked sequentially. This process generates the correlated features among different expressions, and hence affects the accuracy. This research moves toward addressing these issues. The authors' approach entails extracting discriminative features from the informative regions of a face. In this view, they propose an informative region extraction model, which models the importance of facial regions based on the projection of the expressive face images onto the neural face images. However, in practical scenarios, neutral images may not be available, and therefore the authors propose to estimate a common reference image using Procrustes analysis. Subsequently, weighted‐projection‐based LBP feature is derived from the informative regions of the face and their associated weights. This feature extraction method reduces miss‐classification among different classes of expressions. Experimental results on standard datasets show the efficacy of the proposed method

Tailoring the resonance of bilayer graphene sheets by interlayer sp 3 bonds

Graphene-based resonators are envisioned to build the ultimate limit of two-dimensional nanoelectromechanical system due to their ultrasensitive detection of mass, force, pressure and charge. However, such application has been greatly impeded by their extremely low quality factor. In the present work, we explore, using the large-scale molecular dynamics simulation, the possibility of tailoring the resonance properties of a bilayer graphene sheet (GS) with interlayer sp3 bonds. For the bilayer GS resonator with interlayer sp3 bonds, we discovered that the sp3 bonds can either degrade or enhance the resonance properties of the resonator depending on their density and location. It is found that the distribution of sp3 bonds only along the edges of either pristine or hydrogenated bilayer GS, leads to a greatly enhanced quality factor. A quality factor of ~1.18×105 is observed for a 3.07×15.31 nm2 bilayer GS resonator with sp3 bonds, which is more than 30 times larger comparing with that of a pristine bilayer GS. The present study demonstrates that the resonance properties of a bilayer GS resonator can be tuned by introducing sp3 bonds. This finding provides a useful guideline for the synthesis of the bilayer GS for its application as a resonator component