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: "modeling and analysis of two way relay non orthogonal multiple access systems"
  Abstract: A two-way relay non-orthogonal multiple access (TWR-NOMA) system is investigated, where two groups of NOMA users exchange messages with the aid of one half-duplex decode-and-forward relay. Since the signal-plus-interference-to-noise ratios of NOMA signals mainly depend on effective successive interference cancellation (SIC) schemes, imperfect SIC (ipSIC), and perfect SIC (pSIC) are taken into account. In order to characterize the performance of TWR-NOMA systems, we first derive closed-form expressions for both exact and asymptotic outage probabilities of NOMA users’ signals with ipSIC/pSIC. Based on the derived results, the diversity order and throughput of the system are examined. Then, we study the ergodic rates of users’ signals by providing the asymptotic analysis in high signal-to-noise ratio (SNR) regimes. Finally, numerical simulations are provided to verify the analytical results and show that: 1) TWR-NOMA is superior to TWR-OMA in terms of outage probability in low SNR regimes; 2) due to the impact of interference signal at the relay, error floors and throughput ceilings exist in outage probabilities, and ergodic rates for TWR-NOMA, respectively; and 3) in delay-limited transmission mode, TWR-NOMA with ipSIC and pSIC have almost the same energy efficiency. However, in delay-tolerant transmission mode, TWR-NOMA with pSIC is capable of achieving larger energy efficiency compared with TWR-NOMA with ipSIC.

Connected through hyperedge HE-1 (induced by source paper "interplay between noma and other emerging technologies a survey"):
  with members:
    - "secure relaying in non orthogonal multiple access trusted and untrusted scenarios"
    - "securing downlink massive mimo noma networks with artificial noise"
    - "lens based millimeter wave reconfigurable antenna noma"
    - "what role can noma play in massive mimo"
    - "noma an information theoretic perspective"
    - "joint power and time allocation for noma mec offloading"
    - "multi beam noma for hybrid mmwave systems"
    - "exploiting full half duplex user relaying in noma systems"

Connected through hyperedge HE-2 (induced by source paper "exploiting noma for uav communications in large scale cellular networks"):
  with members:
    - "downlink non orthogonal multiple access noma in poisson networks"
    - "exploiting noma for multi beam uav communication in cellular uplink"
    - "user association and resource allocation in unified non orthogonal multiple access enabled heterogeneous ultra dense networks"
    - "connectivity and blockage effects in millimeter wave air to everything networks"
    - "uav aided offloading for cellular hotspot"
    - "energy minimization for wireless communication with rotary wing uav"
    - "cellular enabled uav communication a connectivity constrained trajectory optimization perspective"
    - "multiple antenna aided noma in uav networks a stochastic geometry approach"

Connected through hyperedge HE-3 (induced by source paper "capacity and outage analysis of a dual hop decode and forward relay aided noma scheme"):
  with members:
    - "non orthogonal multiple access for cooperative communications challenges opportunities and trends"
    - "performance analysis of a hybrid downlink uplink cooperative noma scheme"
    - "power domain non orthogonal multiple access noma in 5g systems potentials and challenges"
    - "a survey on non orthogonal multiple access for 5g networks research challenges and future trends"
    - "on the performance of noma based cooperative relaying systems over rician fading channels"
    - "outage performance for cooperative noma transmission with an af relay"
    - "dynamic user clustering and power allocation for uplink and downlink non orthogonal multiple access noma systems"
    - "towards 1 gbps ue in cellular systems understanding ultra dense small cell deployments"

Connected through hyperedge HE-4 (induced by source paper "heterogeneous power splitting based two way df relaying with non linear energy harvesting"):
  with members:
    - "simultaneous information and energy flow for iot relay systems with crowd harvesting"
    - "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)