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: "wireless powered cooperative communications via a hybrid relay"
  Abstract: In this paper, we consider a wireless-powered cooperative communication network, which consists of a hybrid access-point (AP), a hybrid relay, and an information source. In contrast to the conventional cooperative networks, the source in the considered network is assumed to have no embedded energy supply. Thus, it first needs to harvest energy from the signals broadcast by the AP and/or relay, which have constant power supply, in the downlink (DL) before transmitting the information to the AP in the uplink (UL). The hybrid relay can not only help to forward information in the UL but also charge the source with wireless energy transfer in the DL. Considering different possible operations of the hybrid relay, we propose two cooperative protocols for the considered network. We jointly optimize the time and power allocation for DL energy transfer and UL information transmission to maximize the system throughput of the proposed protocols. Numerical results are presented to compare the performance of the proposed protocols and illustrate the impacts of system parameters.

Connected through hyperedge HE-1 (induced by source paper "charge then forward wireless powered communication for multiuser relay networks"):
  with members:
    - "joint power allocation and beamforming for energy efficient two way multi relay communications"
    - "power allocation for secure swipt systems with wireless powered cooperative jamming"
    - "capacity of the two hop relay channel with wireless energy transfer from relay to source and energy transmission cost"
    - "multipair two way relay network with harvest then transmit users resolving pairwise uplink downlink coupling"
    - "artificial noise aided secrecy information and power transfer in ofdma systems"
    - "wireless powered communication opportunities and challenges"
    - "wireless powered relays in cooperative communications time switching relaying protocols and throughput analysis"
    - "harvest then cooperate wireless powered cooperative communications"

Connected through hyperedge HE-2 (induced by source paper "secure wireless powered and cooperative jamming d2d communications"):
  with members:
    - "robust chance constrained optimization for power efficient and secure swipt systems"
    - "wireless powered communication networks an overview"
    - "wireless powered communication opportunities and challenges"
    - "adaptive video streaming for wireless networks with multiple users and helpers"
    - "harvest then cooperate wireless powered cooperative communications"
    - "a survey on device to device communication in cellular networks"
    - "user cooperation in wireless powered communication networks"
    - "throughput maximization in wireless powered communication networks"

Connected through hyperedge HE-3 (induced by source paper "resource allocation strategies for secure wpcn multiantenna multicasting systems"):
  with members:
    - "physical layer security in mimo backscatter wireless systems"
    - "wireless powered communication networks an overview"
    - "optimum wirelessly powered relaying"
    - "harvest then cooperate wireless powered cooperative communications"
    - "robust beamforming for secure communication in systems with wireless information and power transfer"
    - "massive mimo multicasting in noncooperative cellular networks"
    - "user cooperation in wireless powered communication networks"
    - "secrecy wireless information and power transfer with miso beamforming"

Connected through hyperedge HE-4 (induced by source paper "wireless charging technologies fundamentals standards and network applications"):
  with members:
    - "secrecy wireless information and power transfer in fading wiretap channel"
    - "resource allocation in wireless networks with rf energy harvesting and transfer"
    - "wireless powered communication opportunities and challenges"
    - "performance analysis of ambient rf energy harvesting with repulsive point process modeling"
    - "distributed power splitting for swipt in relay interference channels using game theory"
    - "green wireless power transfer networks"
    - "energy harvesting wireless communications a review of recent advances"
    - "joint wireless information and power transfer for an autonomous multiple antenna relay system"

Connected through hyperedge HE-5 (induced by source paper "on wireless energy and information transfer in relay networks"):
  with members:
    - "rf based energy harvesting in decode and forward relaying systems ergodic and outage capacities"
    - "wireless powered relays in cooperative communications time switching relaying protocols and throughput analysis"
    - "relay selection in wireless powered cooperative networks with energy storage"
    - "joint power splitting and antenna selection in energy harvesting relay channels"
    - "outage minimization for a fading wireless link with energy harvesting transmitter and receiver"
    - "harvest then cooperate wireless powered cooperative communications"
    - "wireless networks with rf energy harvesting a contemporary survey"
    - "outage probability of energy harvesting relay aided cooperative networks over rayleigh fading channel"

Connected through hyperedge HE-6 (induced by source paper "on the performance of multi antenna wireless powered communications with energy beamforming"):
  with members:
    - "resource allocation in wireless networks with rf energy harvesting and transfer"
    - "wireless powered communication opportunities and challenges"
    - "an adaptive transmission protocol for wireless powered cooperative communications"
    - "harvest then cooperate wireless powered cooperative communications"
    - "user cooperation in wireless powered communication networks"
    - "multi user scheduling schemes for simultaneous wireless information and power transfer over fading channels"
    - "power allocation strategies in energy harvesting wireless cooperative networks"
    - "optimized training design for wireless energy transfer"

Connected through hyperedge HE-7 (induced by source paper "capacity of the two hop relay channel with wireless energy transfer from relay to source and energy transmission cost"):
  with members:
    - "throughput analysis and optimization of wireless powered multiple antenna full duplex relay systems"
    - "a geometric analysis of the awgn channel with a sigma rho power constraint"
    - "wireless powered communication opportunities and challenges"
    - "rate maximization of decode and forward relaying systems with rf energy harvesting"
    - "optimal cooperative power allocation for energy harvesting enabled relay networks"
    - "multiple access fading channel with wireless power transfer and energy harvesting"
    - "power allocation strategies in energy harvesting wireless cooperative networks"
    - "power allocation for conventional and buffer aided link adaptive relaying systems with energy harvesting nodes"

Connected through hyperedge HE-8 (induced by source paper "cooperative strategies for wireless powered communications"):
  with members:
    - "end to end throughput maximization for underlay multi hop cognitive radio networks with rf energy harvesting"
    - "optimizing df cognitive radio networks with full duplex enabled energy access points"
    - "to harvest and jam a paradigm of self sustaining friendly jammers for secure af relaying"
    - "wireless powered communication opportunities and challenges"
    - "distributed and optimal resource allocation for power beacon assisted wireless powered communications"
    - "harvest then cooperate wireless powered cooperative communications"
    - "wireless networks with rf energy harvesting a contemporary survey"
    - "relaying protocols for wireless energy harvesting and information processing"

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)