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: "energy crowdsourcing and peer to peer energy trading in blockchain enabled smart grids"
  Abstract: The power grid is rapidly transforming, and while recent grid innovations increased the utilization of advanced control methods, the next-generation grid demands technologies that enable the integration of distributed energy resources (DERs)---and consumers that both seamlessly buy and sell electricity. This paper develops an optimization model and blockchain-based architecture to manage the operation of crowdsourced energy systems (CES), with peer-to-peer (P2P) energy trading transactions. An operational model of CESs in distribution networks is presented considering various types of energy trading transactions and crowdsourcees. Then, a two-phase operation algorithm is presented: Phase I focuses on the day-ahead scheduling of generation and controllable DERs, whereas Phase II is developed for hour-ahead or real-time operation of distribution networks. The developed approach supports seamless P2P energy trading between individual prosumers and/or the utility. The presented operational model can also be used to operate islanded microgrids. The CES framework and the operation algorithm are then prototyped through an efficient blockchain implementation, namely the IBM Hyperledger Fabric. This implementation allows the system operator to manage the network users to seamlessly trade energy. Case studies and prototype illustration are provided.

Connected through hyperedge HE-1 (induced by source paper "peer to peer trading in electricity networks an overview"):
  with members:
    - "a motivational game theoretic approach for peer to peer energy trading in the smart grid"
    - "blockchain technologies for smart energy systems fundamentals challenges and solutions"
    - "decentralized p2p energy trading under network constraints in a low voltage network"
    - "peer to peer energy trading with sustainable user participation a game theoretic approach"
    - "price discrimination for energy trading in smart grid a game theoretic approach"
    - "prioritizing consumers in smart grid a game theoretic approach"
    - "three party energy management with distributed energy resources in smart grid"

Connected through hyperedge HE-2 (induced by source paper "cyberphysical blockchain enabled peer to peer energy trading"):
  with members:
    - "when energy trading meets blockchain in electrical power system the state of the art"

Connected through hyperedge HE-3 (induced by source paper "peer to peer blockchain based energy trading"):
  with members:
    - "when energy trading meets blockchain in electrical power system the state of the art"

Connected through hyperedge HE-4 (induced by source paper "integration of blockchain and cloud of things architecture applications and challenges"):
  with members:
    - "ekiden a platform for confidentiality preserving trustworthy and performant smart contracts"
    - "blockchain technologies for the internet of things research issues and challenges"
    - "a survey on consensus mechanisms and mining strategy management in blockchain networks"
    - "designing a blockchain based iot with ethereum swarm and lora the software solution to create high availability with minimal security risks"
    - "bpds a blockchain based privacy preserving data sharing for electronic medical records"
    - "a survey on the security of blockchain systems"
    - "wip a novel blockchain based trust model for cloud identity management"
    - "blockchain based smart contracts applications and challenges"

Connected through hyperedge HE-5 (induced by source paper "blockchain for future smart grid a comprehensive survey"):
  with members:
    - "exploring the attack surface of blockchain a systematic overview"
    - "an efficient blockchain based hierarchical authentication mechanism for energy trading in v2g environment"
    - "when energy trading meets blockchain in electrical power system the state of the art"
    - "blockchain based grid operation services for transactive energy systems"
    - "blockchain technologies for smart energy systems fundamentals challenges and solutions"
    - "key management systems for smart grid advanced metering infrastructure a survey"
    - "a survey on the security of blockchain systems"
    - "a survey on security and privacy issues of bitcoin"

Connected through hyperedge HE-6 (induced by source paper "a p2p dominant distribution system architecture"):
  with members:
    - "distribution electricity pricing under uncertainty"
    - "decentralized p2p energy trading under network constraints in a low voltage network"
    - "blockchain assisted crowdsourced energy systems"

Connected through hyperedge HE-7 (induced by source paper "peer to peer energy trading in distribution systems"):
  with members:
    - "exogenous approach to grid cost allocation in peer to peer electricity markets"
    - "decentralized p2p energy trading under network constraints in a low voltage network"
    - "blockchain assisted crowdsourced energy systems"

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)