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: "acoustic communication for medical nanorobots"
  Abstract: Abstract   Communication among microscopic robots (nanorobots) can coordinate their activities for biomedical tasks. The feasibility of  in vivo  ultrasonic communication is evaluated for micron-size robots broadcasting into various types of tissues. Frequencies between   10    MHz   and   300    MHz   give the best tradeoff between efficient acoustic generation and attenuation for communication over distances of about 100 microns. Based on these results, we find power available from ambient oxygen and glucose in the bloodstream can readily support communication rates of about     10    4      bits/s   between micron-sized robots. We discuss techniques, such as directional acoustic beams, that can increase this rate. The acoustic pressure fields enabling this communication are unlikely to damage nearby tissue, and short bursts at considerably higher power could be of therapeutic use.

Connected through hyperedge HE-1 (induced by source paper "identifying vessel branching from fluid stresses on microscopic robots"):
  with members:
    - "mechanical computing systems using only links and rotary joints"

Connected through hyperedge HE-2 (induced by source paper "energy dissipation by metamorphic micro robots in viscous fluids"):
  with members:
    - "using surface motions for locomotion of microscopic robots in viscous fluids"
    - "chemical power for microscopic robots in capillaries"
    - "multiagent control of self reconfigurable robots"

Connected through hyperedge HE-3 (induced by source paper "using surface motions for locomotion of microscopic robots in viscous fluids"):
  with members:
    - "chemical power for microscopic robots in capillaries"

Connected through hyperedge HE-4 (induced by source paper "distributed control of microscopic robots in biomedical applications"):
  with members:
    - "chemical power for microscopic robots in capillaries"
    - "modeling and mathematical analysis of swarms of microscopic robots"
    - "multiagent control of self reconfigurable robots"

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.RO(Robotics)