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: "buffers improve the performance of relay selection"
  Abstract: We show that the performance of relay selection can be improved by employing relays with buffers. Under the idealized assumption that no buffer is full or empty, the best source-relay and the best relay-destination channels can be simultaneously exploited by selecting the corresponding relays for reception and transmission, respectively. The resulting relay selection scheme is referred to as max-max relay selection (MMRS). Since for finite buffer sizes, empty and full buffers are practically unavoidable if MMRS is employed, we propose a hybrid relay selection (HRS) scheme, which is a combination of conventional best relay selection (BRS) and MMRS. We analyze the outage probabilities of MMRS and HRS and show that both schemes achieve the same diversity gain as conventional BRS and a superior coding gain. Furthermore, our results show that for moderate buffer sizes (e.g. 30 packets) HRS closely approaches the performance of idealized MMRS and the performance gain compared to BRS approaches 3 dB as the number of relays increases.

Connected through hyperedge HE-1 (induced by source paper "on the security analysis of a cooperative incremental relaying protocol in the presence of an active eavesdropper"):
  with members:
    - "power allocation and cooperative diversity in two way non regenerative cognitive radio networks"
    - "security versus reliability analysis of opportunistic relaying"
    - "opportunistic secrecy with a strict delay constraint"
    - "intercept probability analysis of cooperative wireless networks with best relay selection in the presence of eavesdropping attack"
    - "on the design of artificial noise aided secure multi antenna transmission in slow fading channels"
    - "three receiver broadcast channels with side information"
    - "a secure communication game with a relay helping the eavesdropper"
    - "joint relay and jammer selection for secure two way relay networks"

Connected through hyperedge HE-2 (induced by source paper "distributed power control for delay optimization in energy harvesting cooperative relay networks"):
  with members:
    - "energy harvesting two hop communication networks"
    - "learning to cooperate via policy search"
    - "power allocation strategies in energy harvesting wireless cooperative networks"
    - "power allocation for conventional and buffer aided link adaptive relaying systems with energy harvesting nodes"
    - "on green energy powered cognitive radio networks"
    - "throughput maximization for the gaussian relay channel with energy harvesting constraints"
    - "optimal scheduling and power allocation for two hop energy harvesting communication systems"
    - "a survey on delay aware resource control for wireless systems large deviation theory stochastic lyapunov drift and distributed stochastic learning"

Connected through hyperedge HE-3 (induced by source paper "relay assisted primary and secondary transmissions"):
  with members:
    - "optimal random access and random spectrum sensing for an energy harvesting cognitive radio"
    - "cooperative cognitive relaying with ordered cognitive multiple access"

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)