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: "structural results and explicit solution for two player lqg systems on a finite time horizon"
  Abstract: It is well-known that linear dynamical systems with Gaussian noise and quadratic cost (LQG) satisfy a separation principle. Finding the optimal controller amounts to solving separate dual problems; one for control and one for estimation. For the discrete-time finite-horizon case, each problem is a simple forward or backward recursion. In this paper, we consider a generalization of the LQG problem in which there are two controllers. Each controller is responsible for one of two system inputs, but has access to different subsets of the available measurements. Our paper has three main contributions. First, we prove a fundamental structural result: sufficient statistics for the controllers can be expressed as conditional means of the global state. Second, we give explicit state-space formulae for the optimal controller. These formulae are reminiscent of the classical LQG solution with dual forward and backward recursions, but with the important difference that they are intricately coupled. Lastly, we show how these recursions can be solved efficiently, with computational complexity comparable to that of the centralized problem.

Connected through hyperedge HE-1 (induced by source paper "team optimal decentralized state estimation"):
  with members:
    - "decentralized stochastic control with partial history sharing a common information approach"
    - "optimal distributed controller design with communication delays application to vehicle formations"

Connected through hyperedge HE-2 (induced by source paper "decentralized control of stochastically switched linear system with unreliable communication"):
  with members:
    - "optimal local and remote controllers with unreliable uplink channels"
    - "dynamic teams and decentralized control problems with substitutable actions"
    - "optimal local and remote controllers with unreliable communication"
    - "decentralized control problems with substitutable actions"
    - "optimal control of two player systems with output feedback"
    - "decentralized stochastic control with partial history sharing a common information approach"

Connected through hyperedge HE-3 (induced by source paper "optimal local and remote controllers with unreliable uplink channels"):
  with members:
    - "dynamic teams and decentralized control problems with substitutable actions"
    - "optimal local and remote controllers with unreliable communication"
    - "decentralized control problems with substitutable actions"
    - "optimal control of two player systems with output feedback"
    - "decentralized stochastic control with partial history sharing a common information approach"
    - "optimal strategies for communication and remote estimation with an energy harvesting sensor"
    - "optimal decentralized control of coupled subsystems with control sharing"

Connected through hyperedge HE-4 (induced by source paper "optimal local and remote controllers with unreliable communication"):
  with members:
    - "decentralized control problems with substitutable actions"
    - "optimal control of two player systems with output feedback"
    - "decentralized stochastic control with partial history sharing a common information approach"
    - "optimal strategies for communication and remote estimation with an energy harvesting sensor"

Connected through hyperedge HE-5 (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"
    - "decentralized stochastic control with partial history sharing a common information approach"
    - "output feedback h_2 model matching for decentralized systems with delays"

Connected through hyperedge HE-6 (induced by source paper "optimal decentralized state feedback control with sparsity and delays"):
  with members:
    - "optimal control of two player systems with output feedback"
    - "output feedback h_2 model matching for decentralized systems with delays"
    - "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)