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: "maximizing utility among selfish users in social groups"
  Abstract: We consider the problem of a social group of users trying to obtain a "universe" of files, first from a server and then via exchange amongst themselves. We consider the selfish file-exchange paradigm of give-and-take, whereby two users can exchange files only if each has something unique to offer the other. We are interested in maximizing the number of users who can obtain the universe through a schedule of file-exchanges. We first present a practical paradigm of file acquisition. We then present an algorithm which ensures that at least half the users obtain the universe with high probability for $n$ files and $m=O(\log n)$ users when $n\rightarrow\infty$, thereby showing an approximation ratio of 2. Extending these ideas, we show a $1+\epsilon_1$ - approximation algorithm for $m=O(n)$, $\epsilon_1>0$ and a $(1+z)/2 +\epsilon_2$ - approximation algorithm for $m=O(n^z)$, $z>1$, $\epsilon_2>0$. Finally, we show that for any $m=O(e^{o(n)})$, there exists a schedule of file exchanges which ensures that at least half the users obtain the universe.

Connected through hyperedge HE-1 (induced by source paper "the online disjoint set cover problem and its applications"):
  with members:
    - "offline and online incentive mechanism design for smart phone crowd sourcing"
    - "optimally approximating the coverage lifetime of wireless sensor networks"

Connected through hyperedge HE-2 (induced by source paper "strategies for utility maximization in social groups with preferential exploration"):
  with members:
    - "social optimum in social groups with give and take criterion"
    - "evolutionary aided negotiation model for bilateral bargaining in ambient intelligence domains with complex utility functions"
    - "device to device data storage for mobile cellular systems"
    - "pure price of anarchy for generalized second price auction"

Connected through hyperedge HE-3 (induced by source paper "social optimum in social groups with give and take criterion"):
  with members:
    - "device to device data storage for mobile cellular systems"

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.NI(Networking and Internet Architecture)