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: "fused angles a representation of body orientation for balance"
  Abstract: The parameterisation of rotations in three dimensional Euclidean space is an area of applied mathematics that has long been studied, dating back to the original works of Euler in the 18th century. As such, many ways of parameterising a rotation have been developed over the years. Motivated by the task of representing the orientation of a balancing body, the fused angles parameterisation is developed and introduced in this paper. This novel representation is carefully defined both mathematically and geometrically, and thoroughly investigated in terms of the properties it possesses, and how it relates to other existing representations. A second intermediate representation, tilt angles, is also introduced as a natural consequence thereof.

Connected through hyperedge HE-1 (induced by source paper "nimbro robots winning robocup 2018 humanoid adultsize soccer competitions"):
  with members:
    - "grown up nimbro robots winning robocup 2017 humanoid adultsize soccer competitions"
    - "hierarchical and state based architectures for robot behavior planning and control"
    - "omnidirectional bipedal walking with direct fused angle feedback mechanisms"
    - "robocup 2016 humanoid teensize winner nimbro robust visual perception and soccer behaviors"
    - "a monocular vision system for playing soccer in low color information environments"
    - "nimbro op2x adult sized open source 3d printed humanoid robot"
    - "combining simulations and real robot experiments for bayesian optimization of bipedal gait stabilization"
    - "online visual robot tracking and identification using deep lstm networks"

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"
    - "omnidirectional bipedal walking with direct fused angle feedback mechanisms"
    - "a ros based software framework for the nimbro op humanoid open platform"
    - "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 "combining simulations and real robot experiments for bayesian optimization of bipedal gait stabilization"):
  with members:
    - "omnidirectional bipedal walking with direct fused angle feedback mechanisms"
    - "child sized 3d printed igus humanoid open platform"
    - "bayesian optimization using domain knowledge on the atrias biped"
    - "virtual vs real trading off simulations and physical experiments in reinforcement learning with bayesian optimization"
    - "automatic lqr tuning based on gaussian process global optimization"
    - "safe controller optimization for quadrotors with gaussian processes"

Connected through hyperedge HE-4 (induced by source paper "bipedal walking with corrective actions in the tilt phase space"):
  with members:
    - "tilt rotations and the tilt phase space"
    - "omnidirectional bipedal walking with direct fused angle feedback mechanisms"
    - "fused angles and the deficiencies of euler angles"

Connected through hyperedge HE-5 (induced by source paper "online balanced motion generation for humanoid robots"):
  with members:
    - "child sized 3d printed igus humanoid open platform"
    - "prioritized optimal control"
    - "balancing experiments on a torque controlled humanoid with hierarchical inverse dynamics"

Connected through hyperedge HE-6 (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"
    - "a ros based software framework for the nimbro op humanoid open platform"
    - "humanoid teensize open platform nimbro op"

Connected through hyperedge HE-7 (induced by source paper "nimbro op2 grown up 3d printed open humanoid platform for research"):
  with members:
    - "a ros based software framework for the nimbro op humanoid open platform"
    - "child sized 3d printed igus humanoid open platform"
    - "humanoid teensize open platform nimbro op"

Connected through hyperedge HE-8 (induced by source paper "robocup 2016 humanoid teensize winner nimbro robust visual perception and soccer behaviors"):
  with members:
    - "omnidirectional bipedal walking with direct fused angle feedback mechanisms"
    - "child sized 3d printed igus humanoid open platform"

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)