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: "Refactoring a Java code base to AspectJ: an illustrative example"
  Abstract: This paper describes a refactoring process transforming a Java code base into an AspectJ equivalent. The process illustrates 17 aspect-oriented refactorings covering extraction of implementation elements to aspects, internal reorganization of extracted aspects, and extraction of commonalities to superaspects.

Connected through hyperedge HE-1 (induced by source paper "Towards a catalogue of refactorings and code smells for aspectj"):
  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