human: Given a node-centered hypergraph: <hypergraph>, where nodes represent papers and hyperedges represent sets of papers co-cited by a source paper.

Details of the hypergraph:
Center node: "direct mappings between rdf and property graph databases"
  Abstract: Resource Description Framework (RDF) triplestores and Property Graph (PG) database systems are two approaches for data management that are based on modeling, storing and querying graph-like data. Given the heterogeneity between these systems, it becomes necessary to develop methods to allow interoperability among them. While there exist some approaches to exchange data and schema between RDF and PG databases, they lack compatibility and even a solid formal foundation. In this paper, we study the semantic interoperability between RDF and PG databases. Specifically, we present two direct mappings (schema-dependent and schema-independent) for transforming an RDF database into a PG database. We show that the proposed mappings possess the fundamental properties of semantics preservation and information preservation. The existence of both mappings allows us to conclude that the PG data model subsumes the expressiveness or information capacity of the RDF data model.

Connected through hyperedge HE-1 (induced by source paper "rdf 1 1 knowledge representation and data integration language for the web"):
  with members:
    - "foundations of an alternative approach to reification in rdf"
    - "automatic generation of owl ontology from xml data source"
    - "a general framework for representing reasoning and querying with annotated semantic web data"

Question: Please tell me which class the center node belongs to. The 40 classes are: cs.NA(Numerical Analysis), cs.MM(Multimedia), cs.LO(Logic in Computer Science), cs.CY(Computers and Society), cs.CR(Cryptography and Security), cs.DC(Distributed, Parallel, and Cluster Computing), cs.HC(Human-Computer Interaction), cs.CE(Computational Engineering, Finance, and Science), cs.NI(Networking and Internet Architecture), cs.CC(Computational Complexity), cs.AI(Artificial Intelligence), cs.MA(Multiagent Systems), cs.GL(General Literature), cs.NE(Neural and Evolutionary Computing), cs.SC(Symbolic Computation), cs.AR(Hardware Architecture), cs.CV(Computer Vision and Pattern Recognition), cs.GR(Graphics), cs.ET(Emerging Technologies), cs.SY(Systems and Control), cs.CG(Computational Geometry), cs.OH(Other Computer Science), cs.PL(Programming Languages), cs.SE(Software Engineering), cs.LG(Machine Learning), cs.SD(Sound), cs.SI(Social and Information Networks), cs.RO(Robotics), cs.IT(Information Theory), cs.PF(Performance), cs.CL(Computation and Language), cs.IR(Information Retrieval), cs.MS(Mathematical Software), cs.FL(Formal Languages and Automata Theory), cs.DS(Data Structures and Algorithms), cs.OS(Operating Systems), cs.GT(Computer Science and Game Theory), cs.DB(Databases), cs.DL(Digital Libraries), cs.DM(Discrete Mathematics). Directly output the class name.

gpt: cs.DB(Databases)