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: "to harvest and jam a paradigm of self sustaining friendly jammers for secure af relaying"
  Abstract: This paper studies the use of multi-antenna harvest-and-jam (HJ) helpers in a multi-antenna amplify-and-forward (AF) relay wiretap channel assuming that the direct link between the source and destination is broken. Our objective is to maximize the secrecy rate at the destination subject to the transmit power constraints of the AF relay and the HJ helpers. In the case of perfect channel state information (CSI), the joint optimization of the artificial noise (AN) covariance matrix for cooperative jamming and the AF beamforming matrix is studied using semidefinite relaxation (SDR) which is tight, while suboptimal solutions are also devised with lower complexity. For the imperfect CSI case, we provide the equivalent reformulation of the worst-case robust optimization to maximize the minimum achievable secrecy rate. Inspired by the optimal solution to the case of perfect CSI, a suboptimal robust scheme is proposed striking a good tradeoff between complexity and performance. Finally, numerical results for various settings are provided to evaluate the proposed schemes.

Connected through hyperedge HE-1 (induced by source paper "mitigating jamming attacks using energy harvesting"):
  with members:
    - "rf based energy harvesting in decode and forward relaying systems ergodic and outage capacities"
    - "wireless information and power transfer architecture design and rate energy tradeoff"

Connected through hyperedge HE-2 (induced by source paper "secure swipt for directional modulation aided af relaying networks"):
  with members:
    - "spectral and energy efficient wireless powered iot networks noma or tdma"
    - "an overview of sustainable green 5g networks"
    - "a survey on wireless security technical challenges recent advances and future trends"
    - "secrecy wireless information and power transfer challenges and opportunities"
    - "relaying strategies for wireless powered mimo relay networks"
    - "relay selection improves the security reliability trade off in cognitive radio systems"
    - "noncoherent relaying in energy harvesting communication systems"
    - "robust beamforming for secure communication in systems with wireless information and power transfer"

Connected through hyperedge HE-3 (induced by source paper "wireless powered cooperative jamming for secure ofdm system"):
  with members:
    - "waveform optimization for radio frequency wireless power transfer"
    - "waveform design for wireless power transfer"
    - "secrecy wireless information and power transfer in fading wiretap channel"
    - "a general design framework for mimo wireless energy transfer with limited feedback"
    - "wireless power transfer in massive mimo aided hetnets with user association"
    - "accumulate and jam towards secure communication via a wireless powered full duplex jammer"
    - "communications and signals design for wireless power transmission"
    - "wireless powered communication opportunities and challenges"

Connected through hyperedge HE-4 (induced by source paper "exploiting interference for secrecy wireless information and power transfer"):
  with members:
    - "secrecy wireless information and power transfer in fading wiretap channel"
    - "secrecy wireless information and power transfer challenges and opportunities"
    - "accumulate and jam towards secure communication via a wireless powered full duplex jammer"
    - "artificial noise aided secrecy information and power transfer in ofdma systems"
    - "wireless powered communication opportunities and challenges"
    - "wireless powered cooperative jamming for secrecy multi af relaying networks"
    - "robust beamforming for secure communication in systems with wireless information and power transfer"
    - "simultaneous wireless information and power transfer in modern communication systems"

Connected through hyperedge HE-5 (induced by source paper "physical layer security jamming theoretical limits and practical designs in wireless networks"):
  with members:
    - "physical layer security for massive mimo an overview on passive eavesdropping and active attacks"
    - "principles of physical layer security in multiuser wireless networks a survey"
    - "secure communication with a wireless powered friendly jammer"
    - "improving physical layer secrecy using full duplex jamming receivers"
    - "interference assisted secret communication"

Connected through hyperedge HE-6 (induced by source paper "power allocation for secure swipt systems with wireless powered cooperative jamming"):
  with members:
    - "accumulate and jam towards secure communication via a wireless powered full duplex jammer"
    - "energy harvesting for physical layer security in ofdma networks"
    - "secure communication with a wireless powered friendly jammer"

Connected through hyperedge HE-7 (induced by source paper "accumulate and jam towards secure communication via a wireless powered full duplex jammer"):
  with members:
    - "distributed multi relay selection in accumulate then forward energy harvesting relay networks"
    - "throughput analysis and optimization of wireless powered multiple antenna full duplex relay systems"
    - "energy recycling full duplex radios for next generation networks"
    - "distributed power splitting for swipt in relay interference channels using game theory"
    - "multi antenna relay aided wireless physical layer security"
    - "multiuser mimo wireless energy transfer with coexisting opportunistic communication"
    - "harvest then cooperate wireless powered cooperative communications"
    - "robust beamforming for secure communication in systems with wireless information and power transfer"

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"
    - "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 powered cooperative communications via a hybrid relay"
    - "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)