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: "why smart appliances may result in a stupid energy grid"
  Abstract: This article discusses unexpected consequences of idealistic conceptions about the modernization of power grids. We will focus our analysis on demand-response policies based on automatic decisions by the so-called smart home appliances. Following the usual design approach, each individual appliance has access to a universal signal (e.g. grid frequency or electricity price) that is believed to indicate the system state. Such information is then used as the basis of the appliances' individual decisions. While each single device has a negligible impact in the system, the aggregate effect of the distributed appliances' reactions is expect to bring improvements in the system efficiency; this effect is the demand-response policy goal. The smartness of such an ideal system, composed by isolated appliances with their individual decisions, but connected in the same physical grid, may worsen the system stability. This first-sight undesirable outcome comes as a consequence of synchronization among agents that are subject to the same signal. We argue that this effect is in fact byproduct of methodological choices, which are many times implicit. To support this claim, we employ a different approach that understands the electricity system as constituted by physical, informational and regulatory (networked and structured) layers that cannot be reduced to only one or two of them, but have to be viewed as an organic whole. By classifying its structure under this lens, more appropriate management tools can be designed by looking at the system totality in action. Two examples are provided to illustrate the strength of this modeling.

Connected through hyperedge HE-1 (induced by source paper "energy internet via packetized management enabling technologies and deployment challenges"):
  with members:
    - "event based electricity metering an autonomous method to determine transmission thresholds"
    - "finite blocklength communications in smart grids for dynamic spectrum access and locally licensed scenarios"
    - "sparse signal processing for grant free massive connectivity a future paradigm for random access protocols in the internet of things"
    - "increasing the throughput of an unlicensed wireless network through retransmissions"
    - "narrowband iot data transmission procedures for massive machine type communications"
    - "multi layer analysis of iot based systems"
    - "aggregation and resource scheduling in machine type communication networks a stochastic geometry approach"
    - "self regulating supply demand systems"

Connected through hyperedge HE-2 (induced by source paper "analysis of demand control policies using an agent based multi layer power system model"):
  with members:
    - "dynamics of complex systems built as coupled physical communication and decision layers"
    - "agent based model for spot and balancing electricity markets"
    - "models for the modern power grid"
    - "a game theoretic approach to energy trading in the smart grid"

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)