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: "optimal relay selection for physical layer security in cooperative wireless networks"
  Abstract: In this paper, we explore the physical-layer security in cooperative wireless networks with multiple relays where both amplify-and-forward (AF) and decode-and-forward (DF) protocols are considered. We propose the AF and DF based optimal relay selection (i.e., AFbORS and DFbORS) schemes to improve the wireless security against eavesdropping attack. For the purpose of comparison, we examine the traditional AFbORS and DFbORS schemes, denoted by T-AFbORS and T-DFbORS, respectively. We also investigate a so-called multiple relay combining (MRC) framework and present the traditional AF and DF based MRC schemes, called T-AFbMRC and T-DFbMRC, where multiple relays participate in forwarding the source signal to destination which then combines its received signals from the multiple relays. We derive closed-form intercept probability expressions of the proposed AFbORS and DFbORS (i.e., P-AFbORS and P-DFbORS) as well as the T-AFbORS, T-DFbORS, T-AFbMRC and T-DFbMRC schemes in the presence of eavesdropping attack. We further conduct an asymptotic intercept probability analysis to evaluate the diversity order performance of relay selection schemes and show that no matter which relaying protocol is considered (i.e., AF and DF), the traditional and proposed optimal relay selection approaches both achieve the diversity order M where M represents the number of relays. In addition, numerical results show that for both AF and DF protocols, the intercept probability performance of proposed optimal relay selection is strictly better than that of the traditional relay selection and multiple relay combining methods.

Connected through hyperedge HE-1 (induced by source paper "secrecy outage analysis of non orthogonal spectrum sharing for heterogeneous cellular networks"):
  with members:
    - "security reliability tradeoff for distributed antenna systems in heterogeneous cellular networks"
    - "intelligent interference exploitation for heterogeneous cellular networks against eavesdropping"
    - "power domain non orthogonal multiple access noma in 5g systems potentials and challenges"
    - "a new look at physical layer security caching and wireless energy harvesting for heterogeneous ultra dense networks"
    - "physical layer security for spectrum sharing systems"
    - "artificial noise aided secure transmission in large scale spectrum sharing networks"
    - "location based beamforming and physical layer security in rician wiretap channels"
    - "physical layer security in millimeter wave cellular networks"

Connected through hyperedge HE-2 (induced by source paper "secrecy outage for wireless sensor networks"):
  with members:
    - "improving physical layer security in wireless communications using diversity techniques"
    - "intercept behavior analysis of industrial wireless sensor networks in the presence of eavesdropping attack"
    - "rethinking the secrecy outage formulation a secure transmission design perspective"

Connected through hyperedge HE-3 (induced by source paper "secrecy outage analysis for cooperative noma systems with relay selection scheme"):
  with members:
    - "secure relaying in non orthogonal multiple access trusted and untrusted scenarios"
    - "secure transmission to the strong user with optimal power allocation in noma"
    - "multiple antenna assisted non orthogonal multiple access"
    - "spatially random relay selection for full half duplex cooperative noma networks"
    - "non orthogonal multiple access for cooperative communications challenges opportunities and trends"
    - "secure communications in noma system subcarrier assignment and power allocation"
    - "state of the art taxonomy and open issues on cognitive radio networks with noma"
    - "power domain non orthogonal multiple access noma in 5g systems potentials and challenges"

Connected through hyperedge HE-4 (induced by source paper "multi antenna wireless legitimate surveillance systems design and performance analysis"):
  with members:
    - "secure massive mimo systems with limited rf chains"
    - "analysis and design of secure massive mimo systems in the presence of hardware impairments"
    - "on secrecy performance of antenna selection aided mimo systems against eavesdropping"
    - "linear precoding of data and artificial noise in secure massive mimo systems"
    - "throughput analysis and optimization of wireless powered multiple antenna full duplex relay systems"
    - "wireless information surveillance via proactive eavesdropping with spoofing relay"
    - "a survey on wireless security technical challenges recent advances and future trends"
    - "proactive eavesdropping via cognitive jamming in fading channels"

Connected through hyperedge HE-5 (induced by source paper "power constrained secrecy rate maximization for joint relay and jammer selection assisted wireless networks"):
  with members:
    - "a survey on wireless security technical challenges recent advances and future trends"
    - "joint relay and jammer selection improves the physical layer security in the face of csi feedback delays"
    - "improving physical layer security in wireless communications using diversity techniques"
    - "multi antenna relay aided wireless physical layer security"
    - "optimization of code rates in sisome wiretap channels"
    - "on cooperative relaying schemes for wireless physical layer security"
    - "joint relay and jammer selection for secure two way relay networks"
    - "cooperative jamming for secure communications in mimo relay networks"

Connected through hyperedge HE-6 (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"
    - "security versus reliability analysis of opportunistic relaying"
    - "principles of physical layer security in multiuser wireless networks a survey"
    - "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-7 (induced by source paper "energy efficient secrecy in wireless networks based on random jamming"):
  with members:
    - "energy efficient routing in wireless networks in the presence of jamming"
    - "optimal energy and data routing in networks with energy cooperation"
    - "jamming based on an ephemeral key to obtain everlasting security in wireless environments"
    - "secure degrees of freedom of one hop wireless networks"
    - "scaling laws for secrecy capacity in cooperative wireless networks"
    - "efficient wireless security through jamming coding and routing"
    - "everlasting secrecy by exploiting non idealities of the eavesdropper s receiver"
    - "on secrecy capacity scaling in wireless networks"

Connected through hyperedge HE-8 (induced by source paper "secrecy rate maximization with outage constraint in multihop relaying networks"):
  with members:
    - "energy efficient routing in wireless networks in the presence of jamming"
    - "physical layer security of a buffer aided full duplex relaying system"
    - "secure routing in multihop wireless ad hoc networks with decode and forward relaying"
    - "artificial noise aided secrecy information and power transfer in ofdma systems"
    - "energy harvesting for physical layer security in ofdma networks"
    - "when does relay transmission give a more secure connection in wireless ad hoc networks"
    - "relay placement for physical layer security a secure connection perspective"
    - "rethinking the secrecy outage formulation a secure transmission design perspective"

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)