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: "A Demand-Based Spectrum Allocation Algorithm in Cognitive Radio Networks"
  Abstract: The existing spectrum allocation method in CR(Cognitive Radio) focused on the conflict-free allocation and maximize spectrum utilization, etc. without an adequate account of the business requirements of different users. Therefore, the paper introduced a spectrum quality grading method based on fuzzy comprehensive evaluation. A demand-based spectrum allocation algorithm was also proposed based on the combination of graph model and spectrum quality grading. The simulation results shows that the researched algorithm can better satisfy the business requirements of the users and provides them with quality-of-service (QoS) guarantee.

Connected through hyperedge HE-1 (induced by source paper "Cooperative Spectrum Allocation for Cognitive Radio Network: An Evolutionary Approach"):
  with members:
    - "Cooperative Spectrum Sharing in Cognitive Radio Networks: A Game-Theoretic Approach"

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