This paper is devoted to the initial value problems for semilinear wave equations of derivative type with spatial weights in one space dimension. The lifespan estimates classical solutions are quite different from those nonlinearity unknown function itself as global-in-time existence can be established by decay.

Existing methods on facial expression recognition (FER) are mainly trained in the setting when multi-class data is available. However, to detect alien expressions that absent during training, this type of cannot work. To address problem, we develop a Hierarchical Spatial One Class Facial Expression Recognition Network (HS-OCFER) which can construct decision boundary given class (called normal c...