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: "cross layer optimization of fast video delivery in cache enabled relaying networks"
  Abstract: This paper investigates the cross-layer optimization of fast video delivery and caching for minimization of the overall video delivery time in a two-hop relaying network. The half-duplex relay nodes are equipped with both a cache and a buffer which facilitate joint scheduling of fetching and delivery to exploit the channel diversity for improving the overall delivery performance. The fast delivery control is formulated as a two-stage functional non-convex optimization problem. By exploiting the underlying convex and quasi-convex structures, the problem can be solved exactly and efficiently by the developed algorithm. Simulation results show that significant caching and buffering gains can be achieved with the proposed framework, which translates into a reduction of the overall video delivery time. Besides, a trade-off between caching and buffering gains is unveiled.

Connected through hyperedge HE-1 (induced by source paper "secure video streaming in heterogeneous small cell networks with untrusted cache helpers"):
  with members:
    - "on the optimality of separation between caching and delivery in general cache networks"
    - "cache enabled physical layer security for video streaming in backhaul limited cellular networks"
    - "wireless caching technical misconceptions and business barriers"
    - "caching in the sky proactive deployment of cache enabled unmanned aerial vehicles for optimized quality of experience"
    - "on edge caching with secrecy constraints"
    - "energy efficiency of downlink networks with caching at base stations"
    - "5g ultra dense cellular networks"
    - "5g wireless backhaul networks challenges and research advances"

Connected through hyperedge HE-2 (induced by source paper "cache enabled heterogeneous cellular networks optimal tier level content placement"):
  with members:
    - "effect of user mobility on the performance of device to device networks with distributed caching"
    - "optimal geographic caching in finite wireless networks"
    - "content delivery in erasure broadcast channels with cache and feedback"
    - "wireless caching technical misconceptions and business barriers"
    - "analysis and optimization of caching and multicasting in large scale cache enabled heterogeneous wireless networks"
    - "cooperative caching and transmission design in cluster centric small cell networks"
    - "analysis on cache enabled wireless heterogeneous networks"
    - "optimal geographic caching in cellular networks"

Connected through hyperedge HE-3 (induced by source paper "cache enabled physical layer security for video streaming in wireless networks with limited backhaul"):
  with members:
    - "content centric sparse multicast beamforming for cache enabled cloud ran"
    - "fundamental limits of caching with secure delivery"
    - "secure and green swipt in distributed antenna networks with limited backhaul capacity"
    - "cache enabled opportunistic cooperative mimo for video streaming in wireless systems"
    - "fundamental limits of caching"
    - "optimal and robust transmit designs for miso channel secrecy by semidefinite programming"
    - "secure transmission with multiple antennas ii the mimome wiretap channel"

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)