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: "wireless powered cooperative jamming for secure ofdm system"
  Abstract: This paper studies the secrecy communication in an orthogonal frequency division multiplexing system, where a source sends confidential information to a destination in the presence of a potential eavesdropper. We employ wireless powered cooperative jamming to improve the secrecy rate of this system with the assistance of a cooperative jammer, which works in the harvest-then-jam protocol over two time slots. In the first slot, the source sends dedicated energy signals to power the jammer; in the second slot, the jammer uses the harvested energy to jam the eavesdropper, in order to protect the simultaneous secrecy communication from the source to the destination. In particular, we consider two types of receivers at the destination, namely Type-I and Type-II receivers, which do not have and have the capability of canceling the (a priori known) jamming signals, respectively. For both types of receivers, we maximize the secrecy rate at the destination by jointly optimizing the transmit power allocation at the source and the jammer over sub-carriers, as well as the time allocation between the two time slots. First, we present the globally optimal solution to this problem via the Lagrange dual method, which, however, is of high implementation complexity. Next, to balance the tradeoff between the algorithm complexity and performance, we propose alternative low-complexity solutions based on the minorization maximization and heuristic successive optimization, respectively. Simulation results show that the proposed approaches significantly improve the secrecy rate, as compared to benchmark schemes without joint power and time allocation.

Connected through hyperedge HE-1 (induced by source paper "securing uav communications via joint trajectory and power control"):
  with members:
    - "fundamental tradeoffs in communication and trajectory design for uav enabled wireless network"
    - "capacity characterization of uav enabled two user broadcast channel"
    - "the sky is not the limit lte for unmanned aerial vehicles"
    - "robust trajectory and transmit power design for secure uav communications"
    - "placement optimization of uav mounted mobile base stations"
    - "joint trajectory and communication design for multi uav enabled wireless networks"
    - "securing uav communications via trajectory optimization"
    - "fundamental green tradeoffs progresses challenges and impacts on 5g networks"

Connected through hyperedge HE-2 (induced by source paper "common throughput maximization in uav enabled ofdma systems with delay consideration"):
  with members:
    - "capacity characterization of uav enabled two user broadcast channel"
    - "the sky is not the limit lte for unmanned aerial vehicles"
    - "dynamic base station repositioning to improve performance of drone small cells"
    - "placement optimization of uav mounted mobile base stations"
    - "joint trajectory and communication design for multi uav enabled wireless networks"
    - "securing uav communications via trajectory optimization"
    - "fundamental green tradeoffs progresses challenges and impacts on 5g networks"
    - "joint trajectory and communication design for uav enabled multiple access"

Connected through hyperedge HE-3 (induced by source paper "spectral and energy efficient wireless powered iot networks noma or tdma"):
  with members:
    - "energy efficient low power circuits for wireless energy and data transfer in iot sensor nodes"
    - "fundamental green tradeoffs progresses challenges and impacts on 5g networks"
    - "wireless powered communications with non orthogonal multiple access"
    - "an overview of sustainable green 5g networks"
    - "wireless powered communication networks an overview"
    - "energy efficient resource allocation for wireless powered communication networks"
    - "on the performance of non orthogonal multiple access in 5g systems with randomly deployed users"
    - "throughput maximization in wireless powered communication networks"

Connected through hyperedge HE-4 (induced by source paper "intelligent reflecting surface enhanced wireless network joint active and passive beamforming design"):
  with members:
    - "spectral and energy efficient wireless powered iot networks noma or tdma"
    - "beyond massive mimo the potential of data transmission with large intelligent surfaces"
    - "wireless energy beamforming using received signal strength indicator feedback"
    - "fundamental green tradeoffs progresses challenges and impacts on 5g networks"
    - "an overview of sustainable green 5g networks"
    - "energy efficient resource allocation for wireless powered communication networks"
    - "multiuser miso beamforming for simultaneous wireless information and power transfer"
    - "mimo broadcasting for simultaneous wireless information and power transfer"

Connected through hyperedge HE-5 (induced by source paper "energy efficient wireless powered secure transmission with cooperative jamming for public transportation"):
  with members:
    - "cooperative strategies for wireless powered communications"
    - "wireless powered communication opportunities and challenges"
    - "optimal resource allocation in full duplex wireless powered communication network"
    - "on cooperative relaying schemes for wireless physical layer security"
    - "optimal and robust transmit designs for miso channel secrecy by semidefinite programming"

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)