Systems and methods for detecting unintended acceleration of a vehicle. According to the invention, at least a layer of self-curing agent is applied onto a concrete after placing. The system further comprises a hashing data structure residing in RAM, wherein the data structure is designed to occupy a fixed amount of memory independent of content of the data file. The second echo canceller reconstructs a voice signal based upon the silence descriptor information and excitation vector information. A content retriever module is configured to return one or more documents to the user in response to identifying the one or more topics trending that are relevant to the user.