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 trajectory design and energy region characterization"
  Abstract: This paper studies a new unmanned aerial vehicle (UAV)-enabled wireless power transfer (WPT) system, where a UAV-mounted energy transmitter (ET) broadcasts wireless energy to charge distributed energy receivers (ERs) on the ground. In particular, we consider a basic two-user scenario, and investigate how the UAV can optimally exploit its mobility to maximize the amount of energy transferred to the two ERs during a given charging period. We characterize the achievable energy region of the two ERs, by optimizing the UAV's trajectory subject to a maximum speed constraint. We show that when the distance between the two ERs is smaller than a certain threshold, the boundary of the energy region is achieved when the UAV hovers above a fixed location between them for all time; while when their distance is larger than the threshold, to achieve the boundary of the energy region, the UAV in general needs to hover and fly between two different locations above the line connecting them. Numerical results show that the optimized UAV trajectory can significantly improve the WPT efficiency and fairness of the two ERs, especially when the UAV's maximum speed is large and/or the charging duration is long.

Connected through hyperedge HE-1 (induced by source paper "uav communications for 5g and beyond recent advances and future trends"):
  with members:
    - "comparison of limited feedback schemes for noma transmission in mmwave drone networks"
    - "energy optimization for cellular connected multi uav mobile edge computing systems with multi access schemes"
    - "beyond 5g with uavs foundations of a 3d wireless cellular network"
    - "resource allocation for solar powered uav communication systems"
    - "cellular connected uav potentials challenges and promising technologies"
    - "real time optimal resource allocation for embedded uav communication systems"
    - "optimal 3d trajectory design and resource allocation for solar powered uav communication systems"
    - "minimum throughput maximization in uav aided wireless powered communication networks"

Connected through hyperedge HE-2 (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"
    - "uav enabled wireless power transfer with directional antenna a two user case"

Connected through hyperedge HE-3 (induced by source paper "on the performance of renewable energy powered uav assisted wireless communications"):
  with members:
    - "spatial and temporal management of cellular hetnets with multiple solar powered drones"
    - "extracting the most weighted throughput in uav empowered wireless systems with nonlinear energy harvester"
    - "optimal 3d trajectory design and resource allocation for solar powered uav communication systems"
    - "self sustainability of energy harvesting systems concept analysis and design"
    - "optimal transport theory for power efficient deployment of unmanned aerial vehicles"
    - "wireless communications with unmanned aerial vehicles opportunities and challenges"
    - "unmanned aerial vehicle with underlaid device to device communications performance and tradeoffs"
    - "drone small cells in the clouds design deployment and performance analysis"

Connected through hyperedge HE-4 (induced by source paper "throughput maximization for uav enabled wireless powered communication networks"):
  with members:
    - "capacity characterization of uav enabled two user broadcast channel"
    - "placement optimization of uav mounted mobile base stations"
    - "joint trajectory and communication design for multi uav enabled wireless networks"
    - "energy efficient data collection in uav enabled wireless sensor network"
    - "joint trajectory and communication design for uav enabled multiple access"
    - "capacity of uav enabled multicast channel joint trajectory design and power allocation"
    - "uav enabled wireless power transfer trajectory design and energy optimization"
    - "joint offloading and computing optimization in wireless powered mobile edge computing systems"

Connected through hyperedge HE-5 (induced by source paper "optimal 1d trajectory design for uav enabled multiuser wireless power transfer"):
  with members:
    - "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"
    - "3 d placement of an unmanned aerial vehicle base station for maximum coverage of users with different qos requirements"
    - "cellular enabled uav communication a connectivity constrained trajectory optimization perspective"
    - "cellular enabled uav communication trajectory optimization under connectivity constraint"
    - "placement optimization of uav mounted mobile base stations"
    - "joint trajectory and communication design for multi uav enabled wireless networks"
    - "energy efficient data collection in uav enabled wireless sensor network"

Connected through hyperedge HE-6 (induced by source paper "placement optimization for uav enabled wireless networks with multi hop backhaul"):
  with members:
    - "throughput maximization for uav enabled wireless powered communication networks"
    - "joint trajectory and communication design for multi uav enabled wireless networks"
    - "network formation in the sky unmanned aerial vehicles for multi hop wireless backhauling"
    - "energy efficient data collection in uav enabled wireless sensor network"
    - "capacity of uav enabled multicast channel joint trajectory design and power allocation"
    - "uav enabled wireless power transfer trajectory design and energy optimization"
    - "joint altitude and beamwidth optimization for uav enabled multiuser communications"
    - "cyclical multiple access in uav aided communications a throughput delay tradeoff"

Connected through hyperedge HE-7 (induced by source paper "minimum throughput maximization in uav aided wireless powered communication networks"):
  with members:
    - "ultra reliable uav communication using altitude and cooperation diversity"
    - "placement optimization of uav mounted mobile base stations"
    - "joint trajectory and communication design for multi uav enabled wireless networks"
    - "caching in the sky proactive deployment of cache enabled unmanned aerial vehicles for optimized quality of experience"
    - "optimum transmission policies for energy harvesting sensor networks powered by a mobile control center"
    - "wireless communications with unmanned aerial vehicles opportunities and challenges"
    - "mobile edge computing via a uav mounted cloudlet optimization of bit allocation and path planning"
    - "throughput maximization in wireless powered communication networks"

Connected through hyperedge HE-8 (induced by source paper "uav enabled wireless power transfer with directional antenna a two user case"):
  with members:
    - "fundamentals of wireless information and power transfer from rf energy harvester models to signal and system designs"
    - "throughput maximization for uav enabled wireless powered communication networks"
    - "joint altitude and beamwidth optimization for uav enabled multiuser communications"
    - "wireless charging technologies fundamentals standards and network applications"
    - "waveform design for wireless power transfer"
    - "wireless communications with unmanned aerial vehicles opportunities and challenges"
    - "wireless powered communication opportunities and challenges"
    - "practical non linear energy harvesting model and resource allocation for swipt systems"

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)