human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge is induced by one source paper and its member nodes are the cited papers.

Details of the hypergraph:
Center hyperedge (induced by source paper "x wacoda an xml based approach for warehousing and analyzing complex data"):
  Abstract: Data warehousing and OLAP applications must nowadays handle complex data that are not only numerical or symbolic. The XML language is well-suited to logically and physically represent complex data. However, its usage induces new theoretical and practical challenges at the modeling, storage and analysis levels; and a new trend toward XML warehousing has been emerging for a couple of years. Unfortunately, no standard XML data warehouse architecture emerges. In this paper, we propose a unified XML warehouse reference model that synthesizes and enhances related work, and fits into a global XML warehousing and analysis approach we have developed. We also present a software platform that is based on this model, as well as a case study that illustrates its usage.

Includes members:
  Member "indices in xml databases":
    also connected through other hyperedges:
      (none)
  Member "warehousing complex data from the web":
    also connected through other hyperedges:
      (none)
  Member "materialized view selection by query clustering in xml data warehouses":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "warehousing complex data from the web")
  Member "a complex data warehouse for personalized anticipative medicine":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "warehousing complex archaeological objects")
  Member "a join index for xml data warehouses":
    also connected through other hyperedges:
      (none)
  Member "biomedical data warehouses":
    also connected through other hyperedges:
      (none)
  Member "an architecture framework for complex data warehouses":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "warehousing complex data from the web")

Question: Please tell me which class the source paper 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)