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: "enabling secure wireless communications via intelligent reflecting surfaces"
  Abstract: In this paper, we propose to utilize intelligent reflecting surfaces (IRSs) for enhancing the physical layer security of wireless communications systems. In particular, an IRS-assisted secure wireless system is considered, where a multi-antenna transmitter communicates with a single-antenna receiver in the presence of an eavesdropper. To maximize the secrecy rate, both the beamformer at the transmitter and the IRS phase shifts are jointly optimized. Based on the block coordinate descent (BCD) and minorization maximization (MM) techniques, two efficient algorithms are developed to solve the resulting non-convex optimization problem for small- and large-scale IRSs, respectively. Simulation results show that IRSs can significantly improve physical layer security if the proposed algorithms are employed. Furthermore, we reveal that deploying large-scale IRSs is more efficient than enlarging the antenna array size of the transmitter for both boosting the secrecy rate and enhancing the energy efficiency.

Connected through hyperedge HE-1 (induced by source paper "intelligent reflecting surface assisted secure wireless communications with multiple transmit and multiple receive antennas"):
  with members:
    - "secure wireless communication via intelligent reflecting surface"
    - "a survey of optimization approaches for wireless physical layer security"
    - "capacity characterization for intelligent reflecting surface aided mimo communication"
    - "resource allocation for secure irs assisted multiuser miso systems"
    - "secure transmission strategy for intelligent reflecting surface enhanced wireless system"
    - "indoor signal focusing with deep learning designed reconfigurable intelligent surfaces"
    - "intelligent reflecting surface assisted non orthogonal multiple access"
    - "weighted sum power maximization for intelligent reflecting surface aided swipt"

Connected through hyperedge HE-2 (induced by source paper "exploiting randomly located blockages for large scale deployment of intelligent surfaces"):
  with members:
    - "intelligent reflecting surface versus decode and forward how large surfaces are needed to beat relaying"
    - "joint active and passive beamforming optimization for intelligent reflecting surface assisted swipt under qos constraints"
    - "holographic mimo surfaces for 6g wireless networks opportunities challenges and trends"
    - "a novel communication paradigm for high capacity and security via programmable indoor wireless environments in next generation wireless systems"
    - "large intelligent surface antennas lisa making reflective radios smart"
    - "secure wireless communication via intelligent reflecting surface"
    - "reflection probability in wireless networks with metasurface coated environmental objects an approach based on random spatial processes"
    - "resource allocation for secure irs assisted multiuser miso systems"

Connected through hyperedge HE-3 (induced by source paper "joint power control and passive beamforming in irs assisted spectrum sharing"):
  with members:
    - "intelligent reflecting surface assisted multiple access with user pairing noma or oma"
    - "joint active and passive beamforming optimization for intelligent reflecting surface assisted swipt under qos constraints"
    - "holographic mimo surfaces for 6g wireless networks opportunities challenges and trends"
    - "secure wireless communication via intelligent reflecting surface"
    - "capacity characterization for intelligent reflecting surface aided mimo communication"
    - "intelligent reflecting surface meets ofdm protocol design and rate maximization"
    - "intelligent reflecting surface assisted secrecy communication is artificial noise helpful or not"
    - "beamforming optimization for wireless network aided by intelligent reflecting surface with discrete phase shifts"

Connected through hyperedge HE-4 (induced by source paper "resource allocation for irs assisted full duplex cognitive radio systems"):
  with members:
    - "resource allocation for intelligent reflecting surface assisted cognitive radio networks"
    - "miso wireless communication systems via intelligent reflecting surfaces"
    - "capacity characterization for intelligent reflecting surface aided mimo communication"
    - "resource allocation for secure irs assisted multiuser miso systems"
    - "channel estimation for intelligent reflecting surface assisted multiuser communications"
    - "multiple antenna technologies for beyond 5g"
    - "towards smart and reconfigurable environment intelligent reflecting surface aided wireless network"
    - "intelligent reflecting surface enhanced wireless network via joint active and passive beamforming"

Connected through hyperedge HE-5 (induced by source paper "optimal beamforming for miso communications via intelligent reflecting surfaces"):
  with members:
    - "miso wireless communication systems via intelligent reflecting surfaces"
    - "robust and secure wireless communications via intelligent reflecting surfaces"
    - "capacity characterization for intelligent reflecting surface aided mimo communication"
    - "resource allocation for secure irs assisted multiuser miso systems"
    - "channel estimation for intelligent reflecting surface assisted multiuser communications"
    - "multiple antenna technologies for beyond 5g"
    - "towards smart and reconfigurable environment intelligent reflecting surface aided wireless network"
    - "intelligent reflecting surface enhanced wireless network via joint active and passive beamforming"

Connected through hyperedge HE-6 (induced by source paper "analysis and optimization of an intelligent reflecting surface assisted system with interference"):
  with members:
    - "analysis and optimization of outage probability in multi intelligent reflecting surface assisted systems"
    - "cascaded channel estimation for large intelligent metasurface assisted massive mimo"
    - "intelligent reflecting surface assisted non orthogonal multiple access"
    - "weighted sum power maximization for intelligent reflecting surface aided swipt"
    - "intelligent reflecting surface enhanced wireless network via joint active and passive beamforming"
    - "reconfigurable intelligent surfaces for energy efficiency in wireless communication"
    - "large intelligent surface assisted wireless communication exploiting statistical csi"
    - "power efficient multi quality multicast beamforming based on scalable video coding and superposition coding"

Connected through hyperedge HE-7 (induced by source paper "resource allocation for intelligent reflecting surface assisted cognitive radio networks"):
  with members:
    - "miso wireless communication systems via intelligent reflecting surfaces"
    - "robust and secure wireless communications via intelligent reflecting surfaces"
    - "resource allocation for secure irs assisted multiuser miso systems"
    - "beamforming optimization for wireless network aided by intelligent reflecting surface with discrete phase shifts"
    - "multiple antenna technologies for beyond 5g"
    - "towards smart and reconfigurable environment intelligent reflecting surface aided wireless network"
    - "intelligent reflecting surface enhanced wireless network via joint active and passive beamforming"

Connected through hyperedge HE-8 (induced by source paper "irs based wireless jamming attacks when jammers can attack without power"):
  with members:
    - "secure wireless communication via intelligent reflecting surface"
    - "towards smart radio environment for wireless communications via intelligent reflecting surfaces a comprehensive survey"
    - "intelligent reflecting surface enhanced wireless network via joint active and passive beamforming"
    - "reconfigurable intelligent surfaces for energy efficiency in wireless communication"
    - "ambient backscatter communications a contemporary survey"

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)