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: "z sep zonal stable election protocol for wireless sensor networks"
  Abstract: Wireless Sensor Networks (WSNs) are comprised of thousands of sensor nodes, with restricted energy, that cooperate to accomplish a sensing task. Various routing Protocols are designed for transmission in WSNs. In this paper, we proposed a hybrid routing protocol: Zonal-Stable Election Protocol (Z-SEP) for heterogeneous WSNs. In this protocol, some nodes transmit data directly to base station while some use clustering technique to send data to base station as in SEP. We implemented Z-SEP and compared it with traditional Low Energy adaptive clustering hierarchy (LEACH) and SEP. Simulation results showed that Z-SEP enhanced the stability period and throughput than existing protocols like LEACH and SEP.

Connected through hyperedge HE-1 (induced by source paper "dreem me distributed regional energy efficient multi hop routing protocol based on maximum energy in wsns"):
  with members:
    - "eapess an adaptive transmission scheme in wireless sensor networks"
    - "eddeec enhanced developed distributed energy efficient clustering for heterogeneous wireless sensor networks"
    - "q leach a new routing protocol for wsns"
    - "heer hybrid energy efficient reactive protocol for wireless sensor networks"
    - "divide and rule scheme for energy efficient routing in wireless sensor networks"
    - "on adaptive energy efficient transmission in wsns"
    - "ceec centralized energy efficient clustering a new routing protocol for wsns"
    - "optimal number of cluster head selection for efficient distribution of sources in wsns"

Connected through hyperedge HE-2 (induced by source paper "reech me regional energy efficient cluster heads based on maximum energy routing protocol for wsns"):
  with members:
    - "eddeec enhanced developed distributed energy efficient clustering for heterogeneous wireless sensor networks"
    - "q leach a new routing protocol for wsns"
    - "heer hybrid energy efficient reactive protocol for wireless sensor networks"
    - "divide and rule scheme for energy efficient routing in wireless sensor networks"
    - "investigating quality routing link metrics in wireless multi hop networks"
    - "on adaptive energy efficient transmission in wsns"
    - "identifying design requirements for wireless routing link metrics"
    - "performance study of etx based wireless routing metrics"

Connected through hyperedge HE-3 (induced by source paper "lpch and udlpch location aware routing techniques in wsns"):
  with members:
    - "hybrid deec towards efficient energy utilization in wireless sensor networks"
    - "advanced leach a static clustering based heteroneous routing protocol for wsns"
    - "e horm an energy efficient hole removing mechanism in wireless sensor networks"
    - "divide and rule scheme for energy efficient routing in wireless sensor networks"
    - "density controlled divide and rule scheme for energy efficient routing in wireless sensor networks"
    - "on adaptive energy efficient transmission in wsns"
    - "survey of extended leach based clustering routing protocols for wireless sensor networks"

Connected through hyperedge HE-4 (induced by source paper "advanced leach a static clustering based heteroneous routing protocol for wsns"):
  with members:
    - "hybrid deec towards efficient energy utilization in wireless sensor networks"
    - "on modeling geometric joint sink mobility with delay tolerant cluster less wireless sensor networks"
    - "improving network efficiency by removing energy holes in wsns"
    - "on adaptive energy efficient transmission in wsns"
    - "survey of extended leach based clustering routing protocols for wireless sensor networks"

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.NI(Networking and Internet Architecture)