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: "a ros based software framework for the nimbro op humanoid open platform"
  Abstract: Over the past few years, a number of successful humanoid platforms have been developed, including the Nao and the DARwIn-OP, both of which are used by many research groups for the investigation of bipedal walking, full-body motions, and human-robot interaction. The NimbRo-OP is an open humanoid platform under development by team NimbRo of the University of Bonn. Significantly larger than the two aforementioned humanoids, this platform has the potential to interact with a more human-scale environment. This paper describes a software framework for the NimbRo-OP that is based on the Robot Operating System (ROS) middleware. The software provides functionality for hardware abstraction, visual perception, and behavior generation, and has been used to implement basic soccer skills. These were demonstrated at RoboCup 2013, as part of the winning team of the Humanoid League competition.

Connected through hyperedge HE-1 (induced by source paper "motion generation interface of ros to podo software framework for wheeled huamanoid robot"):
  with members:
    - "fast perception planning and execution for a robotic butler wheeled humanoid m hubo"
    - "towards a distributed and real time framework for robots evaluation of ros 2 0 communications for real time robotic applications"

Connected through hyperedge HE-2 (induced by source paper "nimbro op2x adult sized open source 3d printed humanoid robot"):
  with members:
    - "on the convergence of adam and beyond"
    - "grown up nimbro robots winning robocup 2017 humanoid adultsize soccer competitions"
    - "fused angles a representation of body orientation for balance"
    - "omnidirectional bipedal walking with direct fused angle feedback mechanisms"
    - "a monocular vision system for playing soccer in low color information environments"
    - "child sized 3d printed igus humanoid open platform"
    - "combining simulations and real robot experiments for bayesian optimization of bipedal gait stabilization"
    - "nimbro op2 grown up 3d printed open humanoid platform for research"

Connected through hyperedge HE-3 (induced by source paper "child sized 3d printed igus humanoid open platform"):
  with members:
    - "hierarchical and state based architectures for robot behavior planning and control"
    - "fused angles a representation of body orientation for balance"
    - "humanoid teensize open platform nimbro op"

Connected through hyperedge HE-4 (induced by source paper "nimbro op2 grown up 3d printed open humanoid platform for research"):
  with members:
    - "fused angles a representation of body orientation for balance"
    - "child sized 3d printed igus humanoid open platform"
    - "humanoid teensize open platform nimbro op"

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)