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: "discrete time optimal attitude control of a spacecraft with momentum and control constraints"
  Abstract: An algorithm is proposed to solve optimal control problems arising in attitude control of a spacecraft under state and control constraints. First, the discrete-time attitude dynamics are derived by employing discrete mechanics. Then, the orientation transfer, with initial and final values of the orientation and momentum and the time duration being specified, is posed as an energy-optimal control problem in discrete time, subject to momentum and control constraints. Using variational analysis directly on the Lie group SO(3) (the set of 3×3 special orthonormal matrices), first-order necessary conditions for optimality are derived, leading to a constrained two-point boundary value problem. This two-point boundary value problem is solved via a novel multiple shooting technique that employs a root-finding Newton algorithm. Robustness of the multiple shooting technique is demonstrated through a few representative numerical experiments.

Connected through hyperedge HE-1 (induced by source paper "on optimal multiplexing of an ensemble of discrete time constrained control systems on matrix lie groups"):
  with members:
    - "structure preserving constrained optimal trajectory planning of a wheeled inverted pendulum"
    - "a frequency constrained geometric pontryagin maximum principle on matrix lie groups"
    - "discrete optimal control of interconnected mechanical systems"
    - "structure preserving discrete time optimal maneuvers of a wheeled inverted pendulum"
    - "a discrete time pontryagin maximum principle on matrix lie groups"

Connected through hyperedge HE-2 (induced by source paper "discrete optimal control of interconnected mechanical systems"):
  with members:
    - "control synthesis for an underactuated cable suspended system using dynamic decoupling"
    - "a discrete time pontryagin maximum principle on matrix lie groups"

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.SY(Systems and Control)