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: "simultaneous information and energy flow for iot relay systems with crowd harvesting"
  Abstract: It is expected that the number of wireless devices will grow rapidly over the next few years due to the growing proliferation of Internet-of-Things (IoT). In order to improve the energy efficiency of information transfer between small devices, we review state-of-the-art research in simultaneous wireless energy and information transfer, especially for relay based IoT systems. In particular, we analyze simultaneous information-and-energy transfer from the source node, and the design of time-switching and power-splitting operation modes, as well as the associated optimization algorithms. We also investigate the potential of crowd energy harvesting from transmission nodes that belong to multiple radio networks. The combination of source and crowd energy harvesting can greatly reduce the use of battery power and increase the availability and reliability for relaying. We provide insight into the fundamental limits of crowd energy harvesting reliability based on a case study using real city data. Furthermore, we examine the optimization of transmissions in crowd harvesting, especially with the use of node collaboration while guaranteeing Quality-of-Service (QoS).

Connected through hyperedge HE-1 (induced by source paper "simultaneous wireless information and power transfer for decode and forward multihop relay systems in energy constrained iot networks"):
  with members:
    - "end to end throughput maximization for underlay multi hop cognitive radio networks with rf energy harvesting"
    - "retrodirective multi user wireless power transfer with massive mimo"
    - "wireless powered communication opportunities and challenges"
    - "resource allocation techniques for wireless powered communication networks with energy storage constraint"
    - "energy harvesting wireless communications a review of recent advances"
    - "wireless networks with rf energy harvesting a contemporary survey"
    - "application of smart antenna technologies in simultaneous wireless information and power transfer"
    - "wireless information and power transfer a dynamic power splitting approach"

Connected through hyperedge HE-2 (induced by source paper "system outage performance for three step two way energy harvesting df relaying"):
  with members:
    - "heterogeneous power splitting based two way df relaying with non linear energy harvesting"
    - "optimization of a power splitting protocol for two way multiple energy harvesting relay system"
    - "simultaneous wireless information and power transfer in modern communication systems"
    - "wireless networks with rf energy harvesting a contemporary survey"
    - "relaying protocols for wireless energy harvesting and information processing"
    - "a simple cooperative diversity method based on network path selection"

Connected through hyperedge HE-3 (induced by source paper "optimal combining and performance analysis for two way eh relay systems with tdbc protocol"):
  with members:
    - "outage analysis for swipt enabled two way cognitive cooperative communications"
    - "heterogeneous power splitting based two way df relaying with non linear energy harvesting"
    - "energy efficient precoding design for swipt in mimo two way relay networks"
    - "a simple cooperative diversity method based on network path selection"

Connected through hyperedge HE-4 (induced by source paper "on the outage performance of swipt based three step two way df relay networks"):
  with members:
    - "outage analysis for swipt enabled two way cognitive cooperative communications"
    - "cooperative non orthogonal multiple access with simultaneous wireless information and power transfer"

Connected through hyperedge HE-5 (induced by source paper "traffic aware two stage queueing communication networks queue analysis and energy saving"):
  with members:
    - "optimal sleeping mechanism for multiple servers with mmpp based bursty traffic arrival"
    - "what will 5g be"

Connected through hyperedge HE-6 (induced by source paper "heterogeneous power splitting based two way df relaying with non linear energy harvesting"):
  with members:
    - "modeling and analysis of two way relay non orthogonal multiple access systems"
    - "practical non linear energy harvesting model and resource allocation for swipt systems"

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)