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: "secrecy optimized resource allocation for device to device communication underlaying heterogeneous networks"
  Abstract: Device-to-device (D2D) communications recently have attracted much attention for its potential capability to improve spectral efficiency underlaying the existing heterogeneous networks (HetNets). Due to no sophisticated control, D2D user equipments (DUEs) themselves cannot resist eavesdropping or security attacks. It is urgent to maximize the secure capacity for both cellular users and DUEs. This paper formulates the radio resource allocation problem to maximize the secure capacity of DUEs for the D2D communication underlaying HetNets which consist of high power nodes and low power nodes. The optimization objective function with transmit bit rate and power constraints, which is non-convex and hard to be directly derived, is firstly transformed into matrix form. Then the equivalent convex form of the optimization problem is derived according to the Perron-Frobenius theory. A heuristic iterative algorithm based on the proximal theory is proposed to solve this equivalent convex problem through evaluating the proximal operator of Lagrange function. Numerical results show that the proposed radio resource allocation solution significantly improves the secure capacity with a fast convergence speed.

Connected through hyperedge HE-1 (induced by source paper "security reliability tradeoff for distributed antenna systems in heterogeneous cellular networks"):
  with members:
    - "game based approach for qos provisioning and interference management in heterogeneous networks"
    - "intelligent interference exploitation for heterogeneous cellular networks against eavesdropping"
    - "energy efficiency analysis of heterogeneous cellular networks with extra cell range expansion"
    - "safeguarding decentralized wireless networks using full duplex jamming receivers"
    - "optimal beamforming for gaussian mimo wiretap channels with two transmit antennas"
    - "relay selection for wireless communications against eavesdropping a security reliability trade off perspective"
    - "a survey on wireless security technical challenges recent advances and future trends"
    - "physical layer security in heterogeneous cellular networks"

Connected through hyperedge HE-2 (induced by source paper "mode selection and spectrum partition for d2d inband communications a physical layer security perspective"):
  with members:
    - "on secure wireless communications for service oriented computing"
    - "a stochastic geometric analysis of device to device communications operating over generalized fading channels"
    - "mode selection resource allocation and power control for d2d enabled two tier cellular network"
    - "a survey on device to device communication in cellular networks"
    - "spectrum sharing for device to device communication in cellular networks"
    - "principles of physical layer security in multiuser wireless networks a survey"
    - "resource optimization in device to device cellular systems using time frequency hopping"
    - "five disruptive technology directions for 5g"

Connected through hyperedge HE-3 (induced by source paper "resource allocation for secure gaussian parallel relay channels with finite length coding and discrete constellations"):
  with members:
    - "enhancing physical layer security in af relay assisted multicarrier wireless transmission enhancing physical layer security in af relay assisted multicarrier wireless transmission"
    - "joint relay selection and power allocation in large scale mimo systems with untrusted relays and passive eavesdroppers"
    - "optimal power allocation by imperfect hardware analysis in untrusted relaying networks"
    - "secure communication over parallel relay channel"
    - "secure and reliable transmission with cooperative relays in two hop wireless networks"
    - "on secrecy rate analysis of mimo wiretap channels driven by finite alphabet input"
    - "on cooperative relaying schemes for wireless physical layer security"
    - "sum rate maximized resource allocation in multiple df relays aided ofdm transmission"

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)