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: "cooperative energy trading in comp systems powered by smart grids"
  Abstract: This paper studies the energy management in the coordinated multi-point (CoMP) systems powered by smart grids, where each base station (BS) with local renewable energy generation is allowed to implement the two-way energy trading with the grid. Due to the uneven renewable energy supply and communication energy demand over distributed BSs as well as the difference in the prices for their buying/selling energy from/to the gird, it is beneficial for the cooperative BSs to jointly manage their energy trading with the grid and energy consumption in CoMP based communication for reducing the total energy cost. Specifically, we consider the downlink transmission in one CoMP cluster by jointly optimizing the BSs' purchased/sold energy units from/to the grid and their cooperative transmit precoding, so as to minimize the total energy cost subject to the given quality of service (QoS) constraints for the users. First, we obtain the optimal solution to this problem by developing an algorithm based on techniques from convex optimization and the uplink-downlink duality. Next, we propose a sub-optimal solution of lower complexity than the optimal solution, where zero-forcing (ZF) based precoding is implemented at the BSs. Finally, through extensive simulations, we show the performance gain achieved by our proposed joint energy trading and communication cooperation schemes in terms of energy cost reduction, as compared to conventional schemes that separately design communication cooperation and energy trading.

Connected through hyperedge HE-1 (induced by source paper "cross layer scheduling and beamforming in smart grid powered cellular networks with heterogeneous energy coordination"):
  with members:
    - "deep reinforcement learning for adaptive caching in hierarchical content delivery networks"
    - "optimal 3d trajectory design and resource allocation for solar powered uav communication systems"
    - "robust energy efficient beamforming in misome swipt systems with proportional secrecy rate"
    - "dynamic cross layer beamforming in hybrid powered communication systems with harvest use trade strategy"
    - "a hybrid energy sharing framework for green cellular networks"
    - "an overview of sustainable green 5g networks"
    - "ergodic energy management leveraging resource variability in distribution grids"
    - "comp meets smart grid a new communication and energy cooperation paradigm"

Connected through hyperedge HE-2 (induced by source paper "dynamic cross layer beamforming in hybrid powered communication systems with harvest use trade strategy"):
  with members:
    - "energy harvesting wireless communications a review of recent advances"
    - "comp meets smart grid a new communication and energy cooperation paradigm"
    - "a general utility optimization framework for energy harvesting based wireless communications"
    - "a lyapunov optimization approach for green cellular networks with hybrid energy supplies"
    - "cost minimization for fading channels with energy harvesting and conventional energy"
    - "cost aware green cellular networks with energy and communication cooperation"
    - "energy efficient resource allocation in ofdma systems with hybrid energy harvesting base station"
    - "green cellular networks a survey some research issues and challenges"

Connected through hyperedge HE-3 (induced by source paper "energy group buying with loading sharing for green cellular networks"):
  with members:
    - "green 5g heterogeneous networks through dynamic small cell operation"
    - "comp meets smart grid a new communication and energy cooperation paradigm"
    - "bargaining based mobile data offloading"
    - "what will 5g be"
    - "joint energy and spectrum cooperation for cellular communication systems"
    - "cost aware green cellular networks with energy and communication cooperation"
    - "energy cooperation in cellular networks with renewable powered base stations"
    - "green cellular networks a survey some research issues and challenges"

Connected through hyperedge HE-4 (induced by source paper "two scale stochastic control for multipoint communication systems with renewables"):
  with members:
    - "power delay tradeoff with predictive scheduling in integrated cellular and wi fi networks"
    - "decentralized energy allocation for wireless networks with renewable energy powered base stations"
    - "group sparse beamforming for green cloud ran"
    - "optimal power cost management using stored energy in data centers"
    - "linear precoding in cooperative mimo cellular networks with limited coordination clusters"
    - "stability and capacity regions or discrete time queueing networks"
    - "networked mimo with clustered linear precoding"

Connected through hyperedge HE-5 (induced by source paper "a hybrid energy sharing framework for green cellular networks"):
  with members:
    - "a stochastic geometry based demand response management framework for cellular networks powered by smart grid"
    - "understanding mobile traffic patterns of large scale cellular towers in urban environment"
    - "cost aware green cellular networks with energy and communication cooperation"
    - "energy cooperation in cellular networks with renewable powered base stations"
    - "green cellular networks a survey some research issues and challenges"

Connected through hyperedge HE-6 (induced by source paper "cost aware green cellular networks with energy and communication cooperation"):
  with members:
    - "comp meets smart grid a new communication and energy cooperation paradigm"
    - "a general utility optimization framework for energy harvesting based wireless communications"
    - "joint energy and spectrum cooperation for cellular communication systems"
    - "throughput maximization for the gaussian relay channel with energy harvesting constraints"
    - "energy cooperation in cellular networks with renewable powered base stations"
    - "optimal save then transmit protocol for energy harvesting wireless transmitters"
    - "green cellular networks a survey some research issues and challenges"
    - "optimal energy allocation for wireless communications with energy harvesting constraints"

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)