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: "security versus reliability analysis of opportunistic relaying"
  Abstract: Physical-layer security is emerging as a promising paradigm of securing wireless communications against eavesdropping between legitimate users, when the main link spanning from a source to a destination has better propagation conditions than the wiretap link from a source to an eavesdropper. In this paper, we identify and analyze the tradeoffs between the security and reliability of wireless communications in the presence of eavesdropping attacks. Typically, the reliability of the main link can be improved by increasing the source's transmit power (or decreasing its date rate) to reduce the outage probability (OP), which unfortunately increases the risk that an eavesdropper succeeds in intercepting the source message through the wiretap link, since the OP of the wiretap link also decreases when a higher transmit power (or lower date rate) is used. We characterize the security-reliability tradeoffs (SRT) of conventional direct transmission from the source to the destination in the presence of an eavesdropper, where the security and reliability are quantified in terms of the intercept probability (IP) by an eavesdropper and the OP experienced at the destination, respectively. To improve the SRT, we then propose opportunistic relay selection (ORS) and quantify the attainable SRT improvement upon increasing the number of relays. It is shown that given the maximum tolerable IP, the OP of our ORS scheme approaches zero for N → ∞, where N is the number of relays. Conversely, given the maximum tolerable OP, the IP of our ORS scheme tends to zero for N → ∞.

Connected through hyperedge HE-1 (induced by source paper "robust beamforming and jamming for enhancing the physical layer security of full duplex radios"):
  with members:
    - "a new design paradigm for secure full duplex multiuser systems"
    - "iterative distributed minimum total mse approach for secure communications in mimo interference channels"
    - "detecting byzantine attacks without clean reference"
    - "secrecy transmit beamforming for heterogeneous networks"
    - "robust beamforming for secure communication in systems with wireless information and power transfer"
    - "secure beamforming for mimo broadcasting with wireless information and power transfer"
    - "in band full duplex wireless challenges and opportunities"
    - "robust secure transmission in miso channels based on worst case optimization"

Connected through hyperedge HE-2 (induced by source paper "non orthogonal multiple access for 5g and beyond"):
  with members:
    - "downlink non orthogonal multiple access with limited feedback"
    - "optimal user scheduling and power allocation for millimeter wave noma systems"
    - "coordinated multi point comp transmission in downlink multi cell noma systems models and spectral efficiency performance"
    - "low complexity receiver for multi level polar coded modulation in non orthogonal multiple access"
    - "massive non orthogonal multiple access for cellular iot potentials and limitations"
    - "power domain non orthogonal multiple access noma in 5g systems potentials and challenges"
    - "modulation and multiple access for 5g networks"
    - "robust beamforming techniques for non orthogonal multiple access systems with bounded channel uncertainties"

Connected through hyperedge HE-3 (induced by source paper "on the security analysis of a cooperative incremental relaying protocol in the presence of an active eavesdropper"):
  with members:
    - "power allocation and cooperative diversity in two way non regenerative cognitive radio networks"
    - "opportunistic secrecy with a strict delay constraint"
    - "intercept probability analysis of cooperative wireless networks with best relay selection in the presence of eavesdropping attack"
    - "on the design of artificial noise aided secure multi antenna transmission in slow fading channels"
    - "three receiver broadcast channels with side information"
    - "a secure communication game with a relay helping the eavesdropper"
    - "joint relay and jammer selection for secure two way relay networks"
    - "buffers improve the performance of relay selection"

Connected through hyperedge HE-4 (induced by source paper "physical layer security aware routing and performance tradeoffs in ad hoc networks"):
  with members:
    - "secure routing in multihop wireless ad hoc networks with decode and forward relaying"
    - "relay selection improves the security reliability trade off in cognitive radio systems"
    - "secure degrees of freedom of one hop wireless networks"
    - "principles of physical layer security in multiuser wireless networks a survey"
    - "optimal relay selection for physical layer security in cooperative wireless networks"
    - "relay placement for physical layer security a secure connection perspective"
    - "on the throughput cost of physical layer security in decentralized wireless networks"
    - "an overview of the transmission capacity of wireless networks"

Connected through hyperedge HE-5 (induced by source paper "joint relay selection and power allocation in large scale mimo systems with untrusted relays and passive eavesdroppers"):
  with members:
    - "joint relay and jammer selection improves the physical layer security in the face of csi feedback delays"
    - "secure massive mimo transmission with an active eavesdropper"
    - "physical layer security for massive mimo an overview on passive eavesdropping and active attacks"
    - "massive mimo for next generation wireless systems"
    - "principles of physical layer security in multiuser wireless networks a survey"
    - "scaling up mimo opportunities and challenges with very large arrays"
    - "secure diversity multiplexing tradeoff of zero forcing transmit scheme at finite snr"
    - "a simple cooperative diversity method based on network path selection"

Connected through hyperedge HE-6 (induced by source paper "energy harvesting based secure two way communication using an untrusted relay"):
  with members:
    - "joint relay selection and power allocation in large scale mimo systems with untrusted relays and passive eavesdroppers"
    - "optimal power allocation and secrecy sum rate in two way untrusted relaying"
    - "joint relay and jammer selection improves the physical layer security in the face of csi feedback delays"
    - "wireless powered relays in cooperative communications time switching relaying protocols and throughput analysis"
    - "secure communication via a wireless energy harvesting untrusted relay"
    - "secure communication with a wireless powered friendly jammer"
    - "secure beamforming for mimo two way communications with an untrusted relay"

Connected through hyperedge HE-7 (induced by source paper "a survey on wireless security technical challenges recent advances and future trends"):
  with members:
    - "relay selection for wireless communications against eavesdropping a security reliability trade off perspective"
    - "improving physical layer security in wireless communications using diversity techniques"
    - "securing physical layer communications for cognitive radio networks"
    - "secrecy outage and diversity analysis of cognitive radio systems"
    - "what will 5g be"
    - "intercept probability analysis of cooperative wireless networks with best relay selection in the presence of eavesdropping attack"
    - "optimal relay selection for physical layer security in cooperative wireless networks"
    - "physical layer security with multiuser scheduling in cognitive radio networks"

Connected through hyperedge HE-8 (induced by source paper "enhancing the physical layer security of non orthogonal multiple access in large scale networks"):
  with members:
    - "nonorthogonal multiple access in large scale underlay cognitive radio networks"
    - "design of massive mimo noma with limited feedback"
    - "secrecy sum rate maximization in non orthogonal multiple access"
    - "energy efficient transmission design in non orthogonal multiple access"
    - "cooperative non orthogonal multiple access with simultaneous wireless information and power transfer"
    - "secure massive mimo transmission with an active eavesdropper"
    - "fairness for non orthogonal multiple access in 5g systems"
    - "a general mimo framework for noma downlink and uplink transmission based on signal alignment"

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)