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: "Methodology of schema integration for new database applications: a practitioner's approach"
  Abstract: A practitionerâ€™s approach to integrate databases and evolve them so as to support new database applications is presented. The approach consists of a joint bottom-up and top-down methodology; the bottom-up approach is taken to integrate existing database using standard schema integration techniques (B-Schema), the top-down approach is used to develop a database schema for the new applications (T-Schema). The T-Schema uses a joint functional-data analysis. The B-schema is evolved by comparing it with the generated T-schema. This facilitates an evolutionary approach to integrate existing databases to support new applications as and when needed. The mutual completeness check of the T-Schema against B-Schema derive the schema modification steps to be performed on B-Schema to meet the requirements of the new database applications. A case study is presented to illustrate the methodology.

Connected through hyperedge HE-1 (induced by source paper "Web data integration for e-commerce applications"):
  with members:
    - "Kopplungsstrategien für Anwendungssysteme im Krankenhaus"

Connected through hyperedge HE-2 (induced by source paper "Federated database systems for managing distributed, heterogeneous, and autonomous databases"):
  with members:
    - "Semantic data models"
    - "Ontology versioning on the semantic web"
    - "Ontology Evolution: Not the Same as Schema Evolution"
    - "GridVine: An Infrastructure for Peer Information Management"
    - "Piazza: data management infrastructure for semantic web applications"
    - "Query optimization"
    - "Entwurf von Datenbankföderationen"
    - "Estimating data accuracy in a federated database environment"

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