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: "stiffness analysis of multi chain parallel robotic systems"
  Abstract: The paper presents a new stiffness modelling method for multi-chain parallel robotic manipulators with flexible links and compliant actuating joints. In contrast to other works, the method involves a FEA-based link stiffness evaluation and employs a new solution strategy of the kinetostatic equations, which allows computing the stiffness matrix for singular postures and to take into account influence of the external forces. The advantages of the developed technique are confirmed by application examples, which deal with stiffness analysis of a parallel manipulator of the Orthoglide family

Connected through hyperedge HE-1 (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 overconstrained parallel manipulators"
    - "accuracy improvement for stiffness modeling of 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-2 (induced by source paper "stiffness modelling of parallelogram based parallel manipulators"):
  with members:
    - "stiffness analysis of overconstrained parallel manipulators"
    - "accuracy improvement for stiffness modeling of parallel manipulators"
    - "parametric stiffness analysis of the orthoglide"

Connected through hyperedge HE-3 (induced by source paper "stiffness analysis of parallel manipulators with preloaded passive joints"):
  with members:
    - "stiffness analysis of overconstrained parallel manipulators"
    - "architecture optimization of a 3 dof translational parallel mechanism for machining applications 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)