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: "zero gradient sum algorithms for distributed convex optimization the continuous time case"
  Abstract: This paper presents a set of continuous-time distributed algorithms that solve unconstrained, separable, convex optimization problems over undirected networks with fixed topologies. The algorithms are developed using a Lyapunov function candidate that exploits convexity, and are called Zero-Gradient-Sum (ZGS) algorithms as they yield nonlinear networked dynamical systems that evolve invariantly on a zero-gradient-sum manifold and converge asymptotically to the unknown optimizer. We also describe a systematic way to construct ZGS algorithms, show that a subset of them actually converge exponentially, and obtain lower and upper bounds on their convergence rates in terms of the network topologies, problem characteristics, and algorithm parameters, including the algebraic connectivity, Laplacian spectral radius, and function curvatures. The findings of this paper may be regarded as a natural generalization of several well-known algorithms and results for distributed consensus, to distributed convex optimization.

Connected through hyperedge HE-1 (induced by source paper "cluster based distributed augmented lagrangian algorithm for a class of constrained convex optimization problems"):
  with members:
    - "linear convergence rate of a class of distributed augmented lagrangian algorithms"
    - "convergence analysis of saddle point problems in time varying wireless systems control theoretical approach"

Connected through hyperedge HE-2 (induced by source paper "distributed algorithms for solving convex inequalities"):
  with members:
    - "a distributed algorithm for solving a linear algebraic equation"
    - "consensus of hybrid multi agent systems"
    - "continuous time consensus under non instantaneous reciprocity"
    - "gossip algorithms for distributed signal processing"
    - "distributed parameter estimation in sensor networks nonlinear observation models and imperfect communication"

Connected through hyperedge HE-3 (induced by source paper "network flows that solve linear equations"):
  with members:
    - "decentralized gradient algorithm for solution of a linear equation"
    - "a distributed algorithm for solving a linear algebraic equation"
    - "a fast distributed solver for symmetric diagonally dominant linear equations"
    - "solving systems of linear equations locally and asynchronously"
    - "distributed strongly convex optimization"
    - "fast distributed gradient methods"
    - "cooperative convex optimization in networked systems augmented lagrangian algorithms with directed gossip communication"
    - "randomized optimal consensus of multi agent systems"

Connected through hyperedge HE-4 (induced by source paper "elm based distributed cooperative learning over networks"):
  with members:
    - "a distributed approach toward discriminative distance metric learning"
    - "incremental gradient subgradient and proximal methods for convex optimization a survey"
    - "big learning with bayesian methods"
    - "graphlab a new framework for parallel machine learning"
    - "sensor networks with random links topology design for distributed consensus"

Connected through hyperedge HE-5 (induced by source paper "distributed continuous time approximate projection protocols for shortest distance optimization problems"):
  with members:
    - "cooperative convex optimization in networked systems augmented lagrangian algorithms with directed gossip communication"
    - "multi agent robust consensus convergence analysis and application"
    - "randomized optimal consensus of multi agent systems"
    - "reaching an optimal consensus dynamical systems that compute intersections of convex sets"

Connected through hyperedge HE-6 (induced by source paper "distributed asynchronous algorithms for solving positive definite linear equations over dynamic networks"):
  with members:
    - "a distributed algorithm for solving a linear algebraic equation"
    - "optimization and analysis of distributed averaging with short node memory"

Connected through hyperedge HE-7 (induced by source paper "a distributed algorithm for solving positive definite linear equations over networks with membership dynamics"):
  with members:
    - "optimization and analysis of distributed averaging with short node memory"

Connected through hyperedge HE-8 (induced by source paper "distributed optimization convergence conditions from a dynamical system perspective"):
  with members:
    - "cooperative convex optimization in networked systems augmented lagrangian algorithms with directed gossip communication"
    - "connectivity and set tracking of multi agent systems guided by multiple moving leaders"
    - "randomized optimal consensus of multi agent systems"
    - "reaching an optimal consensus dynamical systems that compute intersections of convex sets"

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)