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: "communication systems for grid integration of renewable energy resources"
  Abstract: There is growing interest in renewable energy around the world. Since most renewable sources are intermittent in nature, it is a challenging task to integrate renewable energy resources into the power grid infrastructure. In this grid integration, communication systems are crucial technologies, which enable the accommodation of distributed renewable energy generation and play an extremely important role in monitoring, operating, and protecting both renewable energy generators and power systems. In this article, we review some communication technologies available for grid integration of renewable energy resources. Then we present the communication systems used in a real renewable energy project, Bear Mountain Wind Farm in British Columbia, Canada. In addition, we present the communication systems used in photovoltaic power systems. Finally, we outline some research challenges and possible solutions about the communication systems for grid integration of renewable energy resources.

Connected through hyperedge HE-1 (induced by source paper "software defined networks based smart grid communication a comprehensive survey"):
  with members:
    - "response time and availability study of raft consensus in distributed sdn control plane"
    - "software defined microgrid control for resilience against cyber attacks"
    - "enabling hard service guarantees in software defined smart grid infrastructures"
    - "survey on network virtualization hypervisors for software defined networking"
    - "an iot architecture for wide area measurement systems a virtualized pmu based approach"
    - "iot cloud based distribution system state estimation virtual objects and context awareness"
    - "network function virtualization state of the art and research challenges"
    - "software defined optical networks sdons a comprehensive survey"

Connected through hyperedge HE-2 (induced by source paper "information centric wireless networks with mobile edge computing"):
  with members:
    - "pricing and resource allocation via game theory for a small cell video caching system"

Connected through hyperedge HE-3 (induced by source paper "machine to machine m2m communications in virtualized vehicular ad hoc networks"):
  with members:
    - "stochastic geometry modeling of cellular networks analysis simulation and experimental validation"

Connected through hyperedge HE-4 (induced by source paper "green wireless sensor networks with wireless power transfer"):
  with members:
    - "simultaneous information and power transfer for broadband wireless systems"

Connected through hyperedge HE-5 (induced by source paper "security schemes in vehicular ad hoc networks with cognitive radios"):
  with members:
    - "toward cloud based vehicular networks with efficient resource management"

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.IT(Information Theory)