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: "degeneracy study of the forward kinematics of planar 3 rpr parallel manipulators"
  Abstract: This paper investigates two situations in which the forward kinematics of planar 3-RPR parallel manipulators degenerates. These situations have not been addressed before. The first degeneracy arises when the three input joint variables r1, r2 and r3 satisfy a certain relationship. This degeneracy yields a double root of the characteristic polynomial in t, which could be erroneously interpreted as two coalesce assembly modes. But, unlike what arises in non-degenerate cases, this double root yields two sets of solutions for the position coordinates (x, y) of the platform. In the second situation, we show that the forward kinematics degenerates over the whole joint space if the base and platform triangles are congruent and the platform triangle is rotated by 180 deg about one of its sides. For these "degenerate" manipulators, which are defined here for the first time, the forward kinematics is reduced to the solution of a 3rd-degree polynomial and a quadratics in sequence. Such manipulators constitute, in turn, a new family of analytic planar manipulators that would be more suitable for industrial applications.

Connected through hyperedge HE-1 (induced by source paper "cusp points in the parameter space of degenerate 3 rpr planar parallel manipulators"):
  with members:
    - "uniqueness domains and non singular assembly mode changing trajectories"
    - "on the determination of cusp points of 3 rpr parallel manipulators"
    - "kinematic analysis of a class of analytic planar 3 rpr parallel manipulators"
    - "singular curves in the joint space and cusp points of 3 rpr parallel manipulators"

Connected through hyperedge HE-2 (induced by source paper "singular surfaces and cusps in symmetric planar 3 rpr manipulators"):
  with members:
    - "kinematic analysis of a class of analytic planar 3 rpr parallel manipulators"
    - "non singular assembly mode changing motions for 3 rpr parallel manipulators"
    - "definition sets for the direct kinematics of parallel manipulators"
    - "singular curves and cusp points in the joint space of 3 rpr parallel manipulators"
    - "workspace and assembly modes in fully parallel manipulators a descriptive study"

Connected through hyperedge HE-3 (induced by source paper "kinematic analysis of a class of analytic planar 3 rpr parallel manipulators"):
  with members:
    - "non singular assembly mode changing motions for 3 rpr parallel manipulators"
    - "singular curves in the joint space and cusp points of 3 rpr parallel manipulators"
    - "workspace and assembly modes in fully parallel manipulators a descriptive study"

Connected through hyperedge HE-4 (induced by source paper "non singular assembly mode changing motions for 3 rpr parallel manipulators"):
  with members:
    - "architecture optimization of a 3 dof translational parallel mechanism for machining applications the orthoglide"
    - "definition sets for the direct kinematics of parallel manipulators"
    - "an algorithm for computing cusp points in the joint space of 3 rpr parallel manipulators"
    - "singular curves and cusp points in the joint space of 3 rpr parallel manipulators"
    - "the kinematic analysis of a symmetrical three degree of freedom planar parallel manipulator"
    - "workspace and assembly modes in fully parallel manipulators a descriptive study"

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)