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: "output feedback h_2 model matching for decentralized systems with delays"
  Abstract: This paper gives a new solution to the output feedback H_2 model matching problem for a large class of delayed information sharing patterns. Existing methods for such problems typically reduce the decentralized problem to a centralized problem of higher state dimension. In contrast, the controller given in this paper is constructed from the solutions to the centralized control and estimation Riccati equations for the original system. The problem is solved by decomposing the controller into two components. One is centralized, but delayed, while the other is decentralized with finite impulse response (FIR). It is then shown that the optimal controller can be constructed through a combination of centralized spectral factorization and quadratic programming.

Connected through hyperedge HE-1 (induced by source paper "optimal h_2 decentralized control of cone causal spatially invariant systems"):
  with members:
    - "control allocation for wide area coordinated damping"
    - "optimal control strategies in delayed sharing information structures"

Connected through hyperedge HE-2 (induced by source paper "optimal control for lqg systems on graphs part i structural results"):
  with members:
    - "optimal control of two player systems with output feedback"
    - "structural results and explicit solution for two player lqg systems on a finite time horizon"
    - "decentralized stochastic control with partial history sharing a common information approach"

Connected through hyperedge HE-3 (induced by source paper "localized lqr optimal control"):
  with members:
    - "state space solution to a minimum entropy mathcal h _ infty optimal control problem with a nested information constraint"
    - "the h2 control problem for quadratically invariant systems with delays"

Connected through hyperedge HE-4 (induced by source paper "optimal decentralized state feedback control with sparsity and delays"):
  with members:
    - "optimal control of two player systems with output feedback"
    - "structural results and explicit solution for two player lqg systems on a finite time horizon"
    - "on structured realizability and stabilizability of linear systems"
    - "optimal control strategies in delayed sharing information structures"

Connected through hyperedge HE-5 (induced by source paper "the h2 control problem for quadratically invariant systems with delays"):
  with members:
    - "distributed output feedback lqg control with delayed information sharing"
    - "decentralized stochastic control with partial history sharing a common information approach"
    - "on structured realizability and stabilizability of linear systems"
    - "optimal control strategies in delayed sharing information structures"

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)