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 "top k querying of unknown values under order constraints"):
  Abstract: Many practical scenarios make it necessary to evaluate top-k queries over data items with partially unknown values. This paper considers a setting where the values are taken from a numerical domain, and where some partial order constraints are given over known and unknown values: under these constraints, we assume that all possible worlds are equally likely. Our work is the first to propose a principled scheme to derive the value distributions and expected values of unknown items in this setting, with the goal of computing estimated top-k results by interpolating the unknown values from the known ones. We study the complexity of this general task, and show tight complexity bounds, proving that the problem is intractable, but can be tractably approximated. We then consider the case of tree-shaped partial orders, where we show a constructive PTIME solution. We also compare our problem setting to other top-k definitions on uncertain data.

Includes members:
  Member "possible and certain answers for queries over order incomplete data":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "computing possible and certain answers over order incomplete data")
  Member "uncertainty in crowd data sourcing under structural constraints":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "structurally tractable uncertain data")
  Member "a fast and practical method to estimate volumes of convex polytopes":
    also connected through other hyperedges:
      (none)
  Member "on the complexity of mining itemsets from the crowd using taxonomies":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "select your questions wisely for entity resolution with crowd errors")
  Member "human assisted graph search it s okay to ask questions":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "crowd powered data mining")
  Member "a unified approach to ranking in probabilistic databases":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "uncertainty annotated databases a lightweight approach for approximating certain answers extended version")
  Member "semantics and evaluation of top k queries in probabilistic databases":
    also connected through other hyperedges:
      (none)

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)