We then apply a convolution operation using a filter w ∈ R d×h to a window of h words.
the filter w is convolved over the sequence of words in the sentence matrix S to create a feature matrix C. Each feature c i in C is extracted from a window of words x i:i+h−1 , as follow: where f is an activation function, such as sigmoid or tanh, and b ∈ R is a bias.