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: "energy efficient 3d uav bs placement versus mobile users density and circuit power"
  Abstract: Properly 3D placement of unmanned aerial vehicle mounted base stations (UAV-BSs) can effectively prolong the life-time of the mobile ad hoc network, since UAVs are usually powered by batteries. This paper involves the on-board circuit consumption power and considers the optimal placement that minimizes the UAV-recall-frequency (UAV-RF), which is defined to characterize the life-time of this kind of network. Theoretical results show that the optimal vertical and horizontal dimensions of UAV can be decoupled. That is, the optimal hovering altitude is proportional to the coverage radius of UAVs, and the slope is only determined by environment. Dense scattering environment may greatly enlarge the needed hovering altitude. Also, the optimal coverage radius is achieved when the transmit power equals to on-board circuit power, and hence limiting on-board circuit power can effectively enlarge life-time of system. In addition, our proposed 3D placement method only require the statistics of mobile users' density and environment parameters, and hence it's a typical on-line method and can be easily implemented. Also, it can be utilized in scenarios with varying users' density.

Connected through hyperedge HE-1 (induced by source paper "on demand density aware uav base station 3d placement for arbitrarily distributed users with guaranteed data rates"):
  with members:
    - "placement optimization of uav mounted mobile base stations"
    - "backhaul aware robust 3d drone placement in 5g wireless networks"

Connected through hyperedge HE-2 (induced by source paper "spatial configuration of agile wireless networks with drone bss and user in the loop"):
  with members:
    - "on the number and 3d placement of drone base stations in wireless cellular networks"
    - "configurations and diagnosis for ultra dense heterogeneous networks from empirical measurements to technical solutions"
    - "dynamic base station repositioning to improve performance of drone small cells"
    - "placement optimization of uav mounted mobile base stations"
    - "user association and bandwidth allocation for terrestrial and aerial base stations with backhaul considerations"
    - "optimal transport theory for cell association in uav enabled cellular networks"
    - "deployment and trajectory optimization for uavs a quantization theory approach"
    - "spectrum sharing and cyclical multiple access in uav aided cellular offloading"

Connected through hyperedge HE-3 (induced by source paper "beyond empirical models pattern formation driven placement of uav base stations"):
  with members:
    - "on the number and 3d placement of drone base stations in wireless cellular networks"
    - "placement optimization of uav mounted mobile base stations"
    - "mobile unmanned aerial vehicles uavs for energy efficient internet of things communications"
    - "survey of important issues in uav communication networks"
    - "efficient deployment of multiple unmanned aerial vehicles for optimal wireless coverage"
    - "optimal transport theory for power efficient deployment of unmanned aerial vehicles"
    - "a survey about prediction based data reduction in wireless sensor networks"
    - "unmanned aerial vehicle with underlaid device to device communications performance and tradeoffs"

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)