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: "optimal save then transmit protocol for energy harvesting wireless transmitters"
  Abstract: In this paper, the design of a wireless communication device relying exclusively on energy harvesting is considered. Due to the inability of rechargeable energy sources to charge and discharge at the same time, a constraint we term the energy half-duplex constraint, two rechargeable energy storage devices (ESDs) are assumed so that at any given time, there is always one ESD being recharged. The energy harvesting rate is assumed to be a random variable that is constant over the time interval of interest. A save-then-transmit (ST) protocol is introduced, in which a fraction of time {\rho} (dubbed the save-ratio) is devoted exclusively to energy harvesting, with the remaining fraction 1 - {\rho} used for data transmission. The ratio of the energy obtainable from an ESD to the energy harvested is termed the energy storage efficiency, {\eta}. We address the practical case of the secondary ESD being a battery with {\eta} < 1, and the main ESD being a super-capacitor with {\eta} = 1. The optimal save-ratio that minimizes outage probability is derived, from which some useful design guidelines are drawn. In addition, we compare the outage performance of random power supply to that of constant power supply over the Rayleigh fading channel. The diversity order with random power is shown to be the same as that of constant power, but the performance gap can be large. Furthermore, we extend the proposed ST protocol to wireless networks with multiple transmitters. It is shown that the system-level outage performance is critically dependent on the relationship between the number of transmitters and the optimal save-ratio for single-channel outage minimization. Numerical results are provided to validate our proposed study.

Connected through hyperedge HE-1 (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-2 (induced by source paper "distributed multi user wireless charging power allocation"):
  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"
    - "distributed convergence verification for gaussian belief propagation"
    - "distributed hybrid power state estimation under pmu sampling phase errors"
    - "throughput analysis and optimization of wireless powered multiple antenna full duplex relay systems"
    - "distributed clock skew and offset estimation in wireless sensor networks asynchronous algorithm and convergence analysis"
    - "power and load coupling in cellular networks for energy optimization"

Connected through hyperedge HE-3 (induced by source paper "performance of energy buffer aided incremental relaying in cooperative networks"):
  with members:
    - "incremental accumulate then forward relaying in wireless energy harvesting cooperative networks"
    - "wireless powered communication networks an overview"
    - "performance of adaptive link selection with buffer aided relays in underlay cognitive networks"
    - "a discrete time switching protocol for wireless powered communications with energy accumulation"
    - "energy harvesting two hop communication networks"
    - "on off transmission policy for wireless powered communication with energy storage"
    - "performance analysis of wireless powered communication with finite infinite energy storage"
    - "relaying protocols for wireless energy harvesting and information processing"

Connected through hyperedge HE-4 (induced by source paper "optimal user scheduling in energy harvesting wireless networks"):
  with members:
    - "spectral and energy efficient wireless powered iot networks noma or tdma"
    - "robust resource allocation for mimo wireless powered communication networks based on a non linear eh model"
    - "wireless networks with energy harvesting and power transfer joint power and time allocation"
    - "optimal resource allocation in full duplex wireless powered communication network"
    - "simultaneous wireless information and power transfer in modern communication systems"
    - "wireless networks with rf energy harvesting a contemporary survey"
    - "full duplex wireless powered communication network with energy causality"
    - "throughput maximization in wireless powered communication networks"

Connected through hyperedge HE-5 (induced by source paper "energy harvesting communications using dual alternating batteries"):
  with members:
    - "energy harvesting wireless communications a review of recent advances"
    - "universally near optimal online power control for energy harvesting nodes"
    - "basic performance limits and tradeoffs in energy harvesting sensor nodes with finite data and energy storage"

Connected through hyperedge HE-6 (induced by source paper "wireless powered dual hop multi antenna relaying systems impact of csi and antenna correlation"):
  with members:
    - "on the performance of multi antenna wireless powered communications with energy beamforming"
    - "an overview of sustainable green 5g networks"
    - "training based swipt optimal power splitting at the receiver"
    - "joint wireless information and power transfer for an autonomous multiple antenna relay system"
    - "wireless powered communications performance analysis and optimization"
    - "energy efficient resource allocation for wireless powered communication networks"
    - "wireless information and power transfer in relay systems with multiple antennas and interference"
    - "harvest then cooperate wireless powered cooperative communications"

Connected through hyperedge HE-7 (induced by source paper "capacity of a full duplex wirelessly powered communication system with self interference and processing cost"):
  with members:
    - "rf based energy harvesting in decode and forward relaying systems ergodic and outage capacities"
    - "capacity region of gaussian multiple access channels with energy harvesting and energy cooperation"
    - "capacity analysis of discrete energy harvesting channels"
    - "capacity of the energy harvesting gaussian mac"
    - "capacity of the two hop relay channel with wireless energy transfer from relay to source and energy transmission cost"
    - "weighted sum transmit power minimization for full duplex system with swipt and self energy recycling"
    - "capacity of the energy harvesting channel with a finite battery"
    - "energy recycling full duplex radios for next generation networks"

Connected through hyperedge HE-8 (induced by source paper "multi agent reinforcement learning for energy harvesting two hop communications with a partially observable state"):
  with members:
    - "multi access communications with energy harvesting a multi armed bandit model and the optimality of the myopic policy"
    - "iterative dynamic water filling for fading multiple access channels with energy harvesting"
    - "energy harvesting two hop communication networks"
    - "a learning theoretic approach to energy harvesting communication system optimization"
    - "optimal scheduling and power allocation for two hop energy harvesting communication systems"
    - "throughput optimal policies for energy harvesting wireless transmitters with non ideal circuit power"
    - "throughput maximization for an energy harvesting communication system with processing cost"
    - "optimal transmission policies for energy harvesting two hop 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)