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: "accuracy improvement for stiffness modeling of parallel manipulators"
  Abstract: The paper focuses on the accuracy improvement of stiffness models for parallel manipulators, which are employed in high-speed precision machining. It is based on the integrated methodology that combines analytical and numerical techniques and deals with multidimensional lumped-parameter models of the links. The latter replace the link flexibility by localized 6-dof virtual springs describing both translational/rotational compliance and the coupling between them. There is presented detailed accuracy analysis of the stiffness identification procedures employed in the commercial CAD systems (including statistical analysis of round-off errors, evaluating the confidence intervals for stiffness matrices). The efficiency of the developed technique is confirmed by application examples, which deal with stiffness analysis of translational parallel manipulators.

Connected through hyperedge HE-1 (induced by source paper "cad based approach for identification of elasto static parameters of robotic manipulators"):
  with members:
    - "enhanced stiffness modeling of manipulators with passive joints"
    - "stiffness analysis of overconstrained parallel manipulators"
    - "architecture optimization of a 3 dof translational parallel mechanism for machining applications the orthoglide"
    - "parametric stiffness analysis of the orthoglide"

Connected through hyperedge HE-2 (induced by source paper "stiffness modeling of non perfect parallel manipulators"):
  with members:
    - "cartesian stiffness matrix of manipulators with passive joints analytical approach"
    - "enhanced stiffness modeling of manipulators with passive joints"
    - "stiffness analysis of overconstrained parallel manipulators"
    - "architecture optimization of a 3 dof translational parallel mechanism for machining applications the orthoglide"
    - "parametric stiffness analysis of the orthoglide"

Connected through hyperedge HE-3 (induced by source paper "enhanced stiffness modeling of manipulators with passive joints"):
  with members:
    - "stiffness analysis of parallel manipulators with preloaded passive joints"
    - "stiffness analysis of multi chain parallel robotic systems"
    - "stiffness analysis of overconstrained parallel manipulators"
    - "stiffness analysis of 3 d o f overconstrained translational parallel manipulators"
    - "architecture optimization of a 3 dof translational parallel mechanism for machining applications the orthoglide"
    - "parametric stiffness analysis of the orthoglide"
    - "design strategies for the geometric synthesis of orthoglide type mechanisms"

Connected through hyperedge HE-4 (induced by source paper "cartesian stiffness matrix of manipulators with passive joints analytical approach"):
  with members:
    - "stiffness analysis of overconstrained parallel manipulators"
    - "parametric stiffness analysis of the orthoglide"

Connected through hyperedge HE-5 (induced by source paper "performance evaluation of parallel manipulators for milling application"):
  with members:
    - "enhanced stiffness modeling of manipulators with passive joints"
    - "stiffness analysis of overconstrained parallel manipulators"
    - "architecture optimization of a 3 dof translational parallel mechanism for machining applications the orthoglide"
    - "parametric stiffness analysis of the orthoglide"

Connected through hyperedge HE-6 (induced by source paper "stiffness modelling of parallelogram based parallel manipulators"):
  with members:
    - "stiffness analysis of multi chain parallel robotic systems"
    - "stiffness analysis of overconstrained parallel manipulators"
    - "parametric stiffness analysis of the orthoglide"

Connected through hyperedge HE-7 (induced by source paper "nonlinear effects in stiffness modeling of robotic manipulators"):
  with members:
    - "stiffness analysis of overconstrained parallel manipulators"
    - "stiffness analysis of 3 d o f overconstrained translational parallel manipulators"
    - "architecture optimization of a 3 dof translational parallel mechanism for machining applications the orthoglide"
    - "parametric stiffness analysis of the orthoglide"

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)