human: Given a node-centered hypergraph: <hypergraph>, where nodes represent authors and hyperedges represent groups of authors who co-authored the same paper.

Details of the hypergraph:
Center node: "Towards a thread-based parallel direct execution simulator"
  Abstract: Parallel direct execution simulation is an important tool for performance and scalability analysis of large message passing parallel programs executing on top of a virtual computer. However, detailed simulation of message-passing codes requires a great deal of computation. We are therefore interested in pursuing implementation techniques which can decrease this cost. One idea is to implement the application virtual processes as lightweight threads rather than traditional Unix processes, reducing both on-processor communication costs and context switching costs. We describe an initial implementation of a thread-based parallel direct execution simulator. We discuss the advantages of such an approach and present preliminary results that indicate a significant improvement over the process-based approach.

Connected through hyperedge HE-1 (induced by source paper "Parallelized direct execution simulation of message-passing parallel programs"):
  with members:
    (none)

Question: Please tell me which research area the center author belongs to. The 4 classes are: Computer science, Mathematics, Engineering, Economics, Psychology, Business. Directly output the class name.

gpt: Computer science