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: "concept stability for constructing taxonomies of web site users"
  Abstract: Owners of a web-site are often interested in analysis of groups of users of their site. Information on these groups can help optimizing the structure and contents of the site. In this paper we use an approach based on formal concepts for constructing taxonomies of user groups. For decreasing the huge amount of concepts that arise in applications, we employ stability index of a concept, which describes how a group given by a concept extent differs from other such groups. We analyze resulting taxonomies of user groups for three target websites.

Connected through hyperedge HE-1 (induced by source paper "multimodal clustering for community detection"):
  with members:
    - "algorithms for graph constrained coalition formation in the real world"
    - "tensor networks for dimensionality reduction and large scale optimization part 1 low rank tensor decompositions"
    - "towards a closure operator for enumeration of maximal tricliques in tripartite hypergraphs"
    - "towards a unified taxonomy of biclustering methods"
    - "from below approximations in boolean matrix factorization geometry and new algorithm"
    - "clustering boolean tensors"
    - "introduction to formal concept analysis and its applications in information retrieval and related fields"
    - "abacus frequent pattern mining based community discovery in multidimensional networks"

Connected through hyperedge HE-2 (induced by source paper "introduction to formal concept analysis and its applications in information retrieval and related fields"):
  with members:
    - "an fca based boolean matrix factorisation for collaborative filtering"
    - "distributed formal concept analysis algorithms based on an iterative mapreduce framework"
    - "concept relation discovery and innovation enabling technology cordiet"
    - "concept based recommendations for internet advertisement"
    - "learning concept hierarchies from text corpora using formal concept analysis"

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.CY(Computers and Society)