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: "selective cooperative relaying over time varying channels"
  Abstract: In selective cooperative relaying only a single relay out of the set of available relays is activated, hence the available power and bandwidth resources are efficiently utilized. However, implementing selective cooperative relaying in time-varying channels may cause frequent relay switchings that deteriorate the overall performance. In this paper, we study the rate at which a relay switching occurs in selective cooperative relaying applications in time-varying fading channels. In particular, we derive closed-form expressions for the relay switching rate (measured in Hz) for opportunistic relaying (OR) and distributed switch and stay combining (DSSC). Additionally, expressions for the average relay activation time for both of the considered schemes are also provided, reflecting the average time that a selected relay remains active until a switching occurs. Numerical results manifest that DSSC yields considerably lower relay switching rates than OR, along with larger average relay activation times, rendering it a better candidate for implementation of relay selection in fast fading environments.

Connected through hyperedge HE-1 (induced by source paper "relay pair selection in buffer aided successive opportunistic relaying using a multi antenna source"):
  with members:
    - "decoupled uplink and downlink in a wireless system with buffer aided relaying"
    - "virtual full duplex buffer aided relaying in the presence of inter relay interference"
    - "a buffer aided successive opportunistic relay selection scheme with power adaptation and inter relay interference cancellation for cooperative diversity systems"
    - "superposition coded concurrent decode and forward relaying"
    - "recovering multiplexing loss through successive relaying using repetition coding"
    - "a simple cooperative diversity method based on network path selection"
    - "towards the optimal amplify and forward cooperative diversity scheme"

Connected through hyperedge HE-2 (induced by source paper "relay pair selection with source precoding in buffer aided successive opportunistic relaying"):
  with members:
    - "decoupled uplink and downlink in a wireless system with buffer aided relaying"
    - "virtual full duplex buffer aided relaying in the presence of inter relay interference"
    - "a buffer aided successive opportunistic relay selection scheme with power adaptation and inter relay interference cancellation for cooperative diversity systems"
    - "superposition coded concurrent decode and forward relaying"
    - "recovering multiplexing loss through successive relaying using repetition coding"
    - "a simple cooperative diversity method based on network path selection"
    - "towards the optimal amplify and forward cooperative diversity scheme"

Connected through hyperedge HE-3 (induced by source paper "cooperative diversity with mobile nodes capacity outage rate and duration"):
  with members:
    - "outage rates and outage durations of opportunistic relaying systems"
    - "a simple cooperative diversity method based on network path selection"

Connected through hyperedge HE-4 (induced by source paper "cooperative diversity with mobile nodes outage capacity rates and durations"):
  with members:
    - "outage rates and outage durations of opportunistic relaying systems"
    - "a simple cooperative diversity method based on network path selection"

Connected through hyperedge HE-5 (induced by source paper "outage rates and outage durations of opportunistic relaying systems"):
  with members:
    - "a simple cooperative diversity method based on network path selection"

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)