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: "uav enabled wireless power transfer with directional antenna a two user case"
  Abstract: This paper considers an unmanned aerial vehicle (UAV)-enabled wireless power transfer (WPT) system, in which a UAV equipped with a directional antenna is dispatched to deliver wireless energy to charge two energy receivers (ERs) on the ground. Under this setup, we maximize the common (or minimum) energy received by the two ERs over a particular finite charging period, by jointly optimizing the altitude, trajectory, and transmit beamwidth of the UAV, subject to the UAV's maximum speed constraints, as well as the maximum/minimum altitude and beamwidth constraints. However, the common energy maximization is a non-convex optimization problem that is generally difficult to be solved optimally. To tackle this problem, we first ignore the maximum UAV speed constraints and solve the relaxed problem optimally. The optimal solution to the relaxed problem reveals that the UAV should hover above two symmetric locations during the whole charging period, with the corresponding altitude and beamwidth optimized. Next, we study the original problem with the maximum UAV speed constraints considered, for which a heuristic hover-fly-hover trajectory design is proposed based on the optimal symmetric-location-hovering solution to the relaxed problem. Numerical results validate that thanks to the employment of directional antenna with adaptive beamwidth and altitude control, our proposed design significantly improves the common energy received by the two ERs, as compared to other benchmark schemes.

Connected through hyperedge HE-1 (induced by source paper "common throughput maximization for uav enabled interference channel with wireless powered communications"):
  with members:
    - "uav communications for 5g and beyond recent advances and future trends"
    - "fundamentals of wireless information and power transfer from rf energy harvester models to signal and system designs"
    - "capacity characterization of uav enabled two user broadcast channel"
    - "cellular enabled uav communication a connectivity constrained trajectory optimization perspective"
    - "optimal 1d trajectory design for uav enabled multiuser wireless power transfer"
    - "minimum throughput maximization in uav aided wireless powered communication networks"
    - "a tutorial on uavs for wireless networks applications challenges and open problems"
    - "throughput maximization for uav enabled wireless powered communication 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)