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: "max min fair beamforming for swipt systems with non linear eh model"
  Abstract: We study the beamforming design for multiuser systems with simultaneous wireless information and power transfer (SWIPT). Employing a practical non-linear energy harvesting (EH) model, the design is formulated as a non-convex optimization problem for the maximization of the minimum harvested power across several energy harvesting receivers. The proposed problem formulation takes into account imperfect channel state information (CSI) and a minimum required signal-to-interference-plus-noise ratio (SINR). The globally optimal solution of the design problem is obtained via the semidefinite programming (SDP) relaxation approach. Interestingly, we can show that at most one dedicated energy beam is needed to achieve optimality. Numerical results demonstrate that with the proposed design a significant performance gain and improved fairness can be provided to the users compared to two baseline schemes.

Connected through hyperedge HE-1 (induced by source paper "sensitive and nonlinear far field rf energy harvesting in wireless communications"):
  with members:
    - "waveform design for wireless power transfer with limited feedback"
    - "lora backscatter enabling the vision of ubiquitous connectivity"
    - "large scale multiantenna multisine wireless power transfer"
    - "secure swipt networks based on a non linear energy harvesting model"
    - "wireless information and power transfer over an awgn channel nonlinearity and asymmetric gaussian signaling"
    - "prototyping and experimentation of a closed loop wireless power transmission with channel acquisition and waveform optimization"
    - "low complexity adaptive multisine waveform design for wireless power transfer"
    - "robust resource allocation for mimo wireless powered communication networks based on a non linear eh model"

Connected through hyperedge HE-2 (induced by source paper "power efficient and secure wpcns with hardware impairments and non linear eh circuit"):
  with members:
    - "spectral efficiency of multipair massive mimo two way relaying with hardware impairments"
    - "fundamental green tradeoffs progresses challenges and impacts on 5g networks"
    - "power allocation for secure swipt systems with wireless powered cooperative jamming"
    - "robust resource allocation for mimo wireless powered communication networks based on a non linear eh model"
    - "analysis and design of secure massive mimo systems in the presence of hardware impairments"
    - "on the spectral efficiency of massive mimo systems with low resolution adcs"
    - "wireless powered communication networks an overview"
    - "secrecy wireless information and power transfer challenges and opportunities"

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)