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: "tier association probability and spectrum partitioning for maximum rate coverage in multi tier heterogeneous networks"
  Abstract: For a wireless multi-tier heterogeneous network with orthogonal spectrum allocation across tiers, we optimize the association probability and the fraction of spectrum allocated to each tier so as to maximize rate coverage. In practice, the association probability can be controlled using a biased received signal power. The optimization problem is non-convex and we are forced to explore locally optimal solutions. We make two contributions in this paper: first, we show that there exists a relation between the first derivatives of the objective function with respect to each of the optimization variables. This can be used to simplify numerical solutions to the optimization problem. Second, we explore the optimality of the intuitive solution that the fraction of spectrum allocated to each tier should be equal to the tier association probability. We show that, in this case, a closed-form solution exists. Importantly, our numerical results show that there is essentially zero performance loss. The results also illustrate the significant gains possible by jointly optimizing the user association and the resource allocation.

Connected through hyperedge HE-1 (induced by source paper "coverage analysis of two tier hetnets for co channel orthogonal and partial spectrum sharing under fractional load conditions"):
  with members:
    - "fundamentals of cluster centric content placement in cache enabled device to device networks"
    - "modeling and performance analysis of clustered device to device networks"
    - "fundamentals of throughput maximization with random arrivals for m2m communications"
    - "structured spectrum allocation and user association in heterogeneous cellular networks"
    - "multi channel hybrid access femtocells a stochastic geometric analysis"
    - "average rate of downlink heterogeneous cellular networks over generalized fading channels a stochastic geometry approach"
    - "downlink rate distribution in heterogeneous cellular networks under generalized cell selection"
    - "offloading in heterogeneous networks modeling analysis and design insights"

Connected through hyperedge HE-2 (induced by source paper "optimizing user association and spectrum allocation in hetnets a utility perspective"):
  with members:
    - "on stochastic geometry modeling of cellular uplink transmission with truncated channel inversion power control"
    - "distributed pricing based user association for downlink heterogeneous cellular networks"
    - "downlink and uplink decoupling a disruptive architectural design for 5g networks"
    - "modeling analysis and design for carrier aggregation in heterogeneous cellular networks"
    - "analysis of a proportionally fair and locally adaptive spatial aloha in poisson networks"
    - "joint access point selection and power allocation for uplink wireless networks"
    - "downlink mimo hetnets modeling ordering results and performance analysis"
    - "joint resource partitioning and offloading in heterogeneous cellular networks"

Connected through hyperedge HE-3 (induced by source paper "handoff rate and coverage analysis in multi tier heterogeneous networks"):
  with members:
    - "joint resource partitioning and offloading in heterogeneous cellular networks"
    - "structured spectrum allocation and user association in heterogeneous cellular networks"
    - "downlink rate distribution in heterogeneous cellular networks under generalized cell selection"
    - "offloading in heterogeneous networks modeling analysis and design insights"
    - "towards understanding the fundamentals of mobility in cellular networks"
    - "heterogeneous cellular networks with flexible cell association a comprehensive downlink sinr analysis"
    - "modeling heterogeneous network interference using poisson point processes"
    - "modeling and analysis of k tier downlink heterogeneous cellular networks"

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.IT(Information Theory)