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: "how push to talk makes talk less pushy"
  Abstract: This paper presents an exploratory study of college-age students using two-way, push-to-talk cellular radios. We describe the observed and reported use of cellular radio by the participants. We discuss how the half-duplex, lightweight cellular radio communication was associated with reduced interactional commitment, which meant the cellular radios could be used for a wide range of conversation styles. One such style, intermittent conversation, is characterized by response delays. Intermittent conversation is surprising in an audio medium, since it is typically associated with textual media such as instant messaging. We present design implications of our findings.

Connected through hyperedge HE-1 (induced by source paper "where s the party in multi party analyzing the structure of small group sociable talk"):
  with members:
    - "the mad hatter s cocktail party a social mobile audio space supporting multiple simultaneous conversations"

Connected through hyperedge HE-2 (induced by source paper "making space for stories ambiguity in the design of personal communication systems"):
  with members:
    - "the mad hatter s cocktail party a social mobile audio space supporting multiple simultaneous conversations"

Connected through hyperedge HE-3 (induced by source paper "conversation analysis and the user experience"):
  with members:
    - "the mad hatter s cocktail party a social mobile audio space supporting multiple simultaneous conversations"
    - "practical strategies for integrating a conversation analyst in an iterative design process"
    - "sotto voce exploring the interplay of conversation and mobile audio spaces"

Connected through hyperedge HE-4 (induced by source paper "user interfaces and the social negotiation of availability"):
  with members:
    - "the mad hatter s cocktail party a social mobile audio space supporting multiple simultaneous conversations"

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.HC(Human-Computer Interaction)