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: "on green energy powered cognitive radio networks"
  Abstract: Green energy powered cognitive radio (CR) network is capable of liberating the wireless access networks from spectral and energy constraints. The limitation of the spectrum is alleviated by exploiting cognitive networking in which wireless nodes sense and utilize the spare spectrum for data communications, while dependence on the traditional unsustainable energy is assuaged by adopting energy harvesting (EH) through which green energy can be harnessed to power wireless networks. Green energy powered CR increases the network availability and thus extends emerging network applications. Designing green CR networks is challenging. It requires not only the optimization of dynamic spectrum access but also the optimal utilization of green energy. This paper surveys the energy efficient cognitive radio techniques and the optimization of green energy powered wireless networks. Existing works on energy aware spectrum sensing, management, and sharing are investigated in detail. The state of the art of the energy efficient CR based wireless access network is discussed in various aspects such as relay and cooperative radio and small cells. Envisioning green energy as an important energy resource in the future, network performance highly depends on the dynamics of the available spectrum and green energy. As compared with the traditional energy source, the arrival rate of green energy, which highly depends on the environment of the energy harvesters, is rather random and intermittent. To optimize and adapt the usage of green energy according to the opportunistic spectrum availability, we discuss research challenges in designing cognitive radio networks which are powered by energy harvesters.

Connected through hyperedge HE-1 (induced by source paper "harvest or transmit policy for cognitive radio networks a learning theoretic approach"):
  with members:
    - "spectrum access in cognitive radio using a two stage reinforcement learning approach"
    - "optimal harvest or transmit strategy for energy harvesting underlay cognitive radio network"
    - "end to end throughput maximization for underlay multi hop cognitive radio networks with rf energy harvesting"
    - "online time sharing policy in energy harvesting cognitive radio network with channel uncertainty"
    - "on optimal offline time sharing policy for energy harvesting underlay cognitive radio"
    - "on energy cooperation in energy harvesting underlay cognitive radio network"
    - "an optimal transmission policy for energy harvesting systems with continuous energy and data arrivals"
    - "optimal time sharing in underlay cognitive radio systems with rf energy harvesting"

Connected through hyperedge HE-2 (induced by source paper "sensing throughput tradeoff for superior selective reporting based spectrum sensing in energy harvesting hcrns"):
  with members:
    - "an overview of sustainable green 5g networks"
    - "energy management and cross layer optimization for wireless sensor network powered by heterogeneous energy sources"
    - "a simple cooperative diversity method based on network path selection"

Connected through hyperedge HE-3 (induced by source paper "energy efficient resource allocation in machine to machine communications with multiple access and energy harvesting for iot"):
  with members:
    - "on user pairing in noma uplink"
    - "distributed user association in energy harvesting small cell networks an exchange economy with uncertainty"
    - "wireless energy harvesting in a cognitive relay network"
    - "power allocation and scheduling for swipt systems with non linear energy harvesting model"
    - "wireless powered communication opportunities and challenges"
    - "downlink power control in two tier cellular networks with energy harvesting small cells as stochastic games"
    - "power and load coupling in cellular networks for energy optimization"
    - "practical non linear energy harvesting model and resource allocation for swipt systems"

Connected through hyperedge HE-4 (induced by source paper "mimo underlay cognitive radio optimized power allocation effective number of transmit antennas and harvest transmit tradeoff"):
  with members:
    - "rf based energy harvesting in decode and forward relaying systems ergodic and outage capacities"
    - "jointly optimal spatial channel assignment and power allocation for mimo swipt systems"
    - "optimal power allocation and active interference mitigation for spatial multiplexed mimo cognitive systems"
    - "simultaneous spectrum sensing and data reception for cognitive spatial multiplexing distributed systems"
    - "full duplex mimo small cell networks with interference cancellation"
    - "practical non linear energy harvesting model and resource allocation for swipt systems"
    - "energy efficiency in massive mimo based 5g networks opportunities and challenges"
    - "full duplex wireless powered relay with self energy recycling"

Connected through hyperedge HE-5 (induced by source paper "a new interweave cognitive radio scheme for out band energy harvesting systems"):
  with members:
    - "distributed wireless power transfer with energy feedback"
    - "a tractable product channel model for line of sight scenarios"
    - "the kappa mu shadowed fading model with integer fading parameters"
    - "massive machine type communications in 5g physical and mac layer solutions"
    - "green cognitive relaying opportunistically switching between data transmission and energy harvesting"
    - "on the efficiency of far field wireless power transfer"
    - "spatial throughput of mobile ad hoc networks powered by energy harvesting"
    - "throughput maximization in wireless powered communication networks"

Connected through hyperedge HE-6 (induced by source paper "optimal harvest or transmit strategy for energy harvesting underlay cognitive radio network"):
  with members:
    - "on energy cooperation in energy harvesting underlay cognitive radio network"
    - "optimal time sharing in underlay cognitive radio systems with rf energy harvesting"
    - "on information and energy cooperation in energy harvesting cognitive radio"
    - "information and energy cooperation in cognitive radio networks"

Connected through hyperedge HE-7 (induced by source paper "on green multicasting over cognitive radio fading channels"):
  with members:
    - "energy efficient transmission for multicast services in miso distributed antenna systems"
    - "multicasting in cognitive radio networks"

Connected through hyperedge HE-8 (induced by source paper "distributed power control for delay optimization in energy harvesting cooperative relay networks"):
  with members:
    - "energy harvesting two hop communication networks"
    - "learning to cooperate via policy search"
    - "power allocation strategies in energy harvesting wireless cooperative networks"
    - "power allocation for conventional and buffer aided link adaptive relaying systems with energy harvesting nodes"
    - "throughput maximization for the gaussian relay channel with energy harvesting constraints"
    - "optimal scheduling and power allocation for two hop energy harvesting communication systems"
    - "a survey on delay aware resource control for wireless systems large deviation theory stochastic lyapunov drift and distributed stochastic learning"
    - "two hop communication with energy harvesting"

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)