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: "energy cooperation in energy harvesting communications"
  Abstract: In energy harvesting communications, users transmit messages using energy harvested from nature during the course of communication. With an optimum transmit policy, the performance of the system depends only on the energy arrival profiles. In this paper, we introduce the concept of energy cooperation, where a user wirelessly transmits a portion of its energy to another energy harvesting user. This enables shaping and optimization of the energy arrivals at the energy-receiving node, and improves the overall system performance, despite the loss incurred in energy transfer. We consider several basic multi-user network structures with energy harvesting and wireless energy transfer capabilities: relay channel, two-way channel and multiple access channel. We determine energy management policies that maximize the system throughput within a given duration using a Lagrangian formulation and the resulting KKT optimality conditions. We develop a two-dimensional directional water-filling algorithm which optimally controls the flow of harvested energy in two dimensions: in time (from past to future) and among users (from energy-transferring to energy-receiving) and show that a generalized version of this algorithm achieves the boundary of the capacity region of the two-way channel.

Connected through hyperedge HE-1 (induced by source paper "transmission delay minimization in wireless powered communication systems"):
  with members:
    - "power allocation and effective capacity of af successive relays"
    - "optimization and analysis of wireless powered multi antenna cooperative systems"
    - "cross layer optimization for ultra reliable and low latency radio access networks"
    - "wireless powered dual hop multi antenna relaying systems impact of csi and antenna correlation"
    - "effective capacity of receive antenna selection mimo ostbc systems in co channel interference"
    - "wireless charging technologies fundamentals standards and network applications"
    - "wireless powered communication networks an overview"
    - "some new research trends in wirelessly powered communications"

Connected through hyperedge HE-2 (induced by source paper "energy sustainable paradigms and methods for future mobile networks a survey"):
  with members:
    - "information exchange in randomly deployed dense wsns with wireless energy harvesting capabilities"
    - "a stochastic geometry based demand response management framework for cellular networks powered by smart grid"
    - "fog computing based radio access networks issues and challenges"
    - "a hybrid energy sharing framework for green cellular networks"
    - "recent advances in cloud radio access networks system architectures key techniques and open issues"
    - "green networking in cellular hetnets a unified radio resource management framework with base station on off switching"
    - "online ski rental for on off scheduling of energy harvesting base stations"
    - "dynamic clustering and on off strategies for wireless small cell networks"

Connected through hyperedge HE-3 (induced by source paper "rate energy region in wireless information and power transfer new receiver architecture and practical modulation"):
  with members:
    - "wireless powered communication opportunities and challenges"
    - "cognitive wireless powered network spectrum sharing models and throughput maximization"
    - "throughput optimization for massive mimo systems powered by wireless energy transfer"
    - "harvest then cooperate wireless powered cooperative communications"
    - "user cooperation in wireless powered communication networks"
    - "optimal resource allocation in full duplex wireless powered communication network"
    - "full duplex wireless powered communication network with energy causality"
    - "throughput maximization in wireless powered communication networks"

Connected through hyperedge HE-4 (induced by source paper "outage analysis of energy harvesting based opportunistic cooperative communication systems"):
  with members:
    - "rf based energy harvesting in decode and forward relaying systems ergodic and outage capacities"
    - "convergence analysis of the information matrix in gaussian belief propagation"
    - "convergence analysis of belief propagation for pairwise linear gaussian models"
    - "smart charging for electric vehicles a survey from the algorithmic perspective"
    - "wireless information and power transfer architecture design and rate energy tradeoff"

Connected through hyperedge HE-5 (induced by source paper "energy harvesting networks with general utility functions near optimal online policies"):
  with members:
    - "finite horizon energy efficient scheduling with energy harvesting transmitters over fading channels"
    - "online power control optimization for wireless transmission with energy harvesting and storage"
    - "optimal offline and competitive online strategies for transmitter receiver energy harvesting"
    - "optimal policies for wireless networks with energy harvesting transmitters and receivers effects of decoding costs"
    - "iterative dynamic water filling for fading multiple access channels with energy harvesting"
    - "energy harvesting networks with energy cooperation procrastinating policies"
    - "universally near optimal online power control for energy harvesting nodes"
    - "energy harvesting broadband communication systems with processing energy cost"

Connected through hyperedge HE-6 (induced by source paper "joint resource allocation in swipt based multi antenna decode and forward relay networks"):
  with members:
    - "power allocation for secure swipt systems with wireless powered cooperative jamming"
    - "relaying strategies for wireless powered mimo relay networks"
    - "distributed power splitting for swipt in relay interference channels using game theory"
    - "joint wireless information and power transfer for an autonomous multiple antenna relay system"
    - "information and energy cooperation in ofdm relaying protocols and optimization"
    - "joint power splitting and antenna selection in energy harvesting relay channels"
    - "energy harvesting for physical layer security in ofdma networks"
    - "enhancing wireless information and power transfer by exploiting multi antenna techniques"

Connected through hyperedge HE-7 (induced by source paper "near optimal online distortion minimization for energy harvesting nodes"):
  with members:
    - "optimal offline and competitive online strategies for transmitter receiver energy harvesting"
    - "optimal policies for wireless networks with energy harvesting transmitters and receivers effects of decoding costs"
    - "iterative dynamic water filling for fading multiple access channels with energy harvesting"
    - "source channel coding under energy delay and buffer constraints"
    - "energy harvesting networks with energy cooperation procrastinating policies"
    - "universally near optimal online power control for energy harvesting nodes"
    - "energy harvesting broadband communication systems with processing energy cost"
    - "throughput maximization for the gaussian relay channel with energy harvesting constraints"

Connected through hyperedge HE-8 (induced by source paper "non orthogonal multiple access schemes in wireless powered communication networks"):
  with members:
    - "optimization of energy constrained wireless powered communication networks with heterogeneous nodes"
    - "wireless powered communications with non orthogonal multiple access"
    - "battery powered devices in wpcns"
    - "on optimal policies in full duplex wireless powered communication networks"
    - "optimal design of non orthogonal multiple access with wireless power transfer"
    - "energy harvesting networks with energy cooperation procrastinating policies"
    - "joint transmission and energy transfer policies for energy harvesting devices with finite batteries"
    - "user cooperation in wireless powered communication 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)