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: "qos challenges and opportunities in wireless sensor actuator networks"
  Abstract: A wireless sensor/actuator network (WSAN) is a group of sensors and actuators that are geographically distributed and interconnected by wireless networks. Sensors gather information about the state of physical world. Actuators react to this information by performing appropriate actions. WSANs thus enable cyber systems to monitor and manipulate the behavior of the physical world. WSANs are growing at a tremendous pace, just like the exploding evolution of Internet. Supporting quality of service (QoS) will be of critical importance for pervasive WSANs that serve as the network infrastructure of diverse applications. To spark new research and development interests in this field, this paper examines and discusses the requirements, critical challenges, and open research issues on QoS management in WSANs. A brief overview of recent progress is given.

Connected through hyperedge HE-1 (induced by source paper "cyber physical control over wireless sensor and actuator networks with packet loss"):
  with members:
    - "network qos management in cyber physical systems"
    - "fuzzy logic control based qos management in wireless sensor actuator networks"
    - "wireless sensor actuator network design for mobile control applications"
    - "flexible time triggered sampling in smart sensor based wireless control systems"
    - "feedback scheduling an event driven paradigm"

Connected through hyperedge HE-2 (induced by source paper "evaluating ieee 802 15 4 for cyber physical systems"):
  with members:
    - "network qos management in cyber physical systems"
    - "wireless sensor actuator network design for mobile control applications"

Connected through hyperedge HE-3 (induced by source paper "cross layer adaptive feedback scheduling of wireless control systems"):
  with members:
    - "feedback scheduling of priority driven control networks"
    - "fuzzy logic control based qos management in wireless sensor actuator networks"
    - "wireless sensor actuator network design for mobile control applications"
    - "flexible time triggered sampling in smart sensor based wireless control systems"
    - "feedback scheduling an event driven paradigm"

Connected through hyperedge HE-4 (induced by source paper "network qos management in cyber physical systems"):
  with members:
    - "fuzzy logic control based qos management in wireless sensor actuator networks"
    - "wireless sensor actuator network design for mobile control applications"
    - "flexible time triggered sampling in smart sensor based wireless control systems"
    - "feedback scheduling an event driven paradigm"

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)