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 efficient relaying over multiple slots with causal csi"
  Abstract: In many communication scenarios, such as in cellular systems, the energy cost is substantial and should be conserved, yet there is a growing need to support many real-time applications that require timely data delivery. To model such a scenario, in this paper we consider the problem of minimizing the expected sum energy of delivering a message of a given size from a source to a destination subject to a deadline constraint. A relay is present and can assist after it has decoded the message. Causal channel state information (CSI), in the form of present and past SNRs of all links, is available for determining the optimal power allocation for the source and relay. We obtain the optimal power allocation policy by dynamic programming and explore its structure. We also obtain conditions for which the minimum expected sum energy is bounded given a general channel distribution. In particular, we show that for Rayleigh and Rician fading channels, relaying is necessary for the minimum expected sum energy to be bounded. This illustrates the fundamental advantage of relaying from the perspective of energy efficient communications when only causal CSI is available. Numerical results are obtained which show the reduction in the expected sum energy under different communication scenarios.

Connected through hyperedge HE-1 (induced by source paper "event trigger based robust optimal control for energy harvesting transmitter"):
  with members:
    - "closed form delay optimal power control for energy harvesting wireless system with finite energy storage"
    - "a learning theoretic approach to energy harvesting communication system optimization"
    - "on the delay throughput tradeoff in distributed wireless networks"
    - "broadcasting with an energy harvesting rechargeable transmitter"
    - "sum rate optimal power policies for energy harvesting transmitters in an interference channel"
    - "optimal energy allocation for wireless communications with energy harvesting constraints"
    - "competitive ratio analysis of online algorithms to minimize data transmission time in energy harvesting communication system"
    - "a general framework for the optimization of energy harvesting communication systems with battery imperfections"

Connected through hyperedge HE-2 (induced by source paper "power and load coupling in cellular networks for energy optimization"):
  with members:
    - "data offloading in load coupled networks a utility maximization framework"
    - "spectral efficiency and energy efficiency of ofdm systems impact of power amplifiers and countermeasures"
    - "analysis of cell load coupling for lte network planning and optimization"
    - "contractive interference functions and rates of convergence of distributed power control laws"
    - "green cellular networks a survey some research issues and challenges"

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)