  The Science4cast 2021 competition focuses on predicting future edges in an
evolving semantic network, where each vertex represents an artificial
intelligence concept, and an edge between a pair of vertices denotes that the
two concepts have been investigated together in a scientific paper. In this
paper, we describe our solution to this competition. We present two distinct
approaches: a tree-based gradient boosting approach and a deep learning
approach, and demonstrate that both approaches achieve competitive performance.
Our final solution, which is based on a blend of the two approaches, achieved
the 1st place among all the participating teams. The source code for this paper
is available at https://github.com/YichaoLu/Science4cast2021.
