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: "an exhaustive study of the workspace topologies of all 3r orthogonal manipulators with geometric simplifications"
  Abstract: Abstract   This paper proposes a classification of three-revolute orthogonal manipulators that have at least one of their DH parameters equal to zero. This classification is based on the topology of their workspace. The workspace is characterized in a half cross-section by the singular curves. The workspace topology is defined by the number of cusps and nodes that appear on these singular curves. The manipulators are classified into different types with similar kinematic properties. Each type is evaluated according to interesting kinematic properties such as, whether the workspace is fully reachable with four inverse kinematic solutions or not, the existence of voids, and the feasibility of continuous trajectories in the workspace. It is found that several orthogonal manipulators have a “well-connected” workspace, that is, their workspace is fully accessible with four inverse kinematic solutions and any continuous trajectory is feasible. This result is of interest for the design of alternative manipulator geometries.

Connected through hyperedge HE-1 (induced by source paper "an algebraic method to check the singularity free paths for parallel robots"):
  with members:
    - "non singular assembly mode changing trajectories in the workspace for the 3 rps parallel robot"
    - "uniqueness domains and non singular assembly mode changing trajectories"
    - "on the determination of cusp points of 3 rpr parallel manipulators"
    - "kinematics and workspace analysis of a three axis parallel manipulator the orthoglide"
    - "an interval analysis based study for the design and the comparison of 3 dof parallel kinematic machines"

Connected through hyperedge HE-2 (induced by source paper "workspace and singularity analysis of a delta like family robot"):
  with members:
    - "non singular assembly mode changing trajectories in the workspace for the 3 rps parallel robot"
    - "uniqueness domains and non singular assembly mode changing trajectories"
    - "kinematics and workspace analysis of a three axis parallel manipulator the orthoglide"
    - "an interval analysis based study for the design and the comparison of 3 dof parallel kinematic machines"

Connected through hyperedge HE-3 (induced by source paper "cuspidal and noncuspidal robot manipulators"):
  with members:
    - "non singular assembly mode changing motions for 3 rpr parallel manipulators"
    - "classification of one family of 3r positioning manipulators"
    - "a classification of 3r orthogonal manipulators by the topology of their workspace"
    - "workspace and assembly modes in fully parallel manipulators a descriptive study"

Connected through hyperedge HE-4 (induced by source paper "a design oriented study for 3r orthogonal manipulators with geometric simplifications"):
  with members:
    - "an interval analysis based study for the design and the comparison of 3 dof parallel kinematic machines"

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)