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: "Using Semantic Web Ontology for Intercloud Directories and Exchanges."
  Abstract: The concept of a cloud operated by one service provider or enterprise interoperating with a clouds operated by another is a powerful idea. So far that is limited to use cases where code running on one cloud explicitly references a service on another cloud. There is no implicit and transparent interoperability. This interoperability should be more than cloud to cloud, it should embody 1-to-many and many-to-many models. Working groups have proposed building a layered set of protocols to solve this interoperability challenge called “Intercloud Protocols”. Instead of each cloud provider establishing connectivity with another cloud provider in a Point-to-Point manner resulting into n 2 complexity problem, Intercloud Directories and Exchanges will help facilitate as mediators for enabling connectivity and collaboration among disparate cloud providers. This paper proposes a mechanism for such mediation utilizing a resources catalog approach, defined using the Semantic Web Resource Definition Framework (RDF) and a common Ontology of Cloud Computing Resources across heterogeneous cloud providers.

Connected through hyperedge HE-1 (induced by source paper "Inter-Cloud architectures and application brokering: taxonomy and survey"):
  with members:
    - "A Virtual Machine Placement Taxonomy"

Connected through hyperedge HE-2 (induced by source paper "A Layered Security Approach for Cloud Computing Infrastructure"):
  with members:
    - "Cloud computing — Issues, research and implementations"

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