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 efficiency maximization of full duplex two way relay with non ideal power amplifiers and non negligible circuit power"
  Abstract: In this paper, we maximize the energy efficiency (EE) of full-duplex (FD) two-way relay (TWR) systems under non-ideal power amplifiers (PAs) and non-negligible transmission-dependent circuit power. We start with the case where only the relay operates full duplex and two timeslots are required for TWR. Then, we extend to the advanced case, where the relay and the two nodes all operate full duplex, and accomplish TWR in a single timeslot. In both cases, we establish the intrinsic connections between the optimal transmit powers and durations, based on which the original non-convex EE maximization can be convexified and optimally solved. Simulations show the superiority of FD-TWR in terms of EE, especially when traffic demand is high. The simulations also reveal that the maximum EE of FD-TWR is more sensitive to the PA efficiency, than it is to self-cancellation. The full FD design of FD-TWR is susceptible to traffic imbalance, while the design with only the relay operating in the FD mode exhibits strong tolerance.

Connected through hyperedge HE-1 (induced by source paper "energy efficiency fairness for multi pair wireless powered relaying systems"):
  with members:
    - "joint power allocation and beamforming for energy efficient two way multi relay communications"
    - "energy efficient beam coordination strategies with rate dependent processing power"
    - "relaying strategies for wireless powered mimo relay networks"
    - "wireless powered relays in cooperative communications time switching relaying protocols and throughput analysis"
    - "practical non linear energy harvesting model and resource allocation for swipt systems"
    - "wireless networks with rf energy harvesting a contemporary survey"
    - "energy efficiency optimization in relay assisted mimo systems with perfect and statistical csi"
    - "power allocation strategies in energy harvesting wireless cooperative networks"

Connected through hyperedge HE-2 (induced by source paper "energy efficient transmission of hybrid array with non ideal power amplifiers and circuitry"):
  with members:
    - "energy efficient transceiver design for hybrid sub array architecture mimo systems"
    - "resolution adaptive hybrid mimo architectures for millimeter wave communications"
    - "effective capacity of licensed assisted access in unlicensed spectrum for 5g from theory to application"
    - "hybrid beamforming for large antenna arrays with phase shifter selection"
    - "an overview of signal processing techniques for millimeter wave mimo systems"
    - "dynamic subarrays for hybrid precoding in wideband mmwave mimo systems"
    - "deploying dense networks for maximal energy efficiency small cells meet massive mimo"
    - "channel estimation and hybrid precoding for millimeter wave cellular systems"

Connected through hyperedge HE-3 (induced by source paper "energy efficiency maximization for comp joint transmission with non ideal power amplifiers"):
  with members:
    - "effective capacity of licensed assisted access in unlicensed spectrum for 5g from theory to application"
    - "deploying dense networks for maximal energy efficiency small cells meet massive mimo"
    - "fundamental limits of cooperation"

Connected through hyperedge HE-4 (induced by source paper "energy reliability aware link optimization for battery powered iot devices with non ideal power amplifiers"):
  with members:
    - "packet error rate analysis of uncoded schemes in block fading channels using extreme value theory"
    - "cross layer optimization of wireless links under reliability and energy constraints"

Connected through hyperedge HE-5 (induced by source paper "energy efficient user access control and resource allocation in hcns with non ideal circuitry"):
  with members:
    - "effective capacity of licensed assisted access in unlicensed spectrum for 5g from theory to application"
    - "user association in 5g networks a survey and an outlook"
    - "deploying dense networks for maximal energy efficiency small cells meet massive mimo"
    - "heterogeneous cellular networks with flexible cell association a comprehensive downlink sinr analysis"
    - "fundamental limits of cooperation"

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)