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: "wsr maximized resource allocation in multiple df relays aided ofdma downlink transmission"
  Abstract: This paper considers the weighted sum rate (WSR) maximized resource allocation (RA) constrained by a system sum power in an orthogonal frequency division multiple access (OFDMA) downlink transmission system assisted by multiple decode-and-forward (DF) relays. In particular, multiple relays may cooperate with the source for every relay-aided transmission. A two-step algorithm is proposed to find the globally optimum RA. In the first step, the optimum source/relay power and assisting relays that maximize the rate is found for every combination of subcarrier and destination, assuming a sum power is allocated to the transmission at that subcarrier to that destination in the relay-aided transmission mode and the direct mode, respectively. In the second step, a convex-optimization based algorithm is designed to find the globally optimum assignment of destination, transmission mode and sum power for each subcarrier to maximize the WSR. Combining the RAs found in the two steps, the globally optimum RA can be found. In addition, we show that the optimum RA in the second step can readily be derived when the system sum power is very high. The effectiveness of the proposed algorithm is illustrated by numerical experiments.

Connected through hyperedge HE-1 (induced by source paper "energy efficient resource allocation for time varying ofdma relay systems with hybrid energy supplies"):
  with members:
    - "cross layer scheduling for ofdma based cognitive radio systems with delay and security constraints"
    - "power allocation for conventional and buffer aided link adaptive relaying systems with energy harvesting nodes"
    - "energy efficient resource allocation in ofdma systems with hybrid energy harvesting base station"
    - "maximizing energy efficiency in multi relay ofdma cellular networks"
    - "decentralized delay optimal control for interference networks with limited renewable energy storage"
    - "jointly optimal channel and power assignment for dual hop multi channel multi user relaying"
    - "a cross layer perspective on energy harvesting aided green communications over fading channels"
    - "adaptive power management for wireless base stations in a smart grid environment"

Connected through hyperedge HE-2 (induced by source paper "weighted sum rate maximization for downlink ofdma with subcarrier pair based opportunistic df relaying"):
  with members:
    - "power minimization for ofdm transmission with subcarrier pair based opportunistic df relaying"
    - "on the scale algorithm for multiuser multicarrier power spectrum management"
    - "joint subcarrier pairing and power allocation for ofdm transmission with decode and forward relaying"
    - "sum rate maximized resource allocation in multiple df relays aided ofdm transmission"
    - "optimization framework and graph based approach for relay assisted bidirectional ofdma cellular networks"

Connected through hyperedge HE-3 (induced by source paper "novel subcarrier pair based opportunistic df protocol for cooperative downlink ofdma"):
  with members:
    - "weighted sum rate maximization for downlink ofdma with subcarrier pair based opportunistic df relaying"
    - "power minimization for ofdm transmission with subcarrier pair based opportunistic df relaying"
    - "joint subcarrier pairing and power allocation for ofdm transmission with decode and forward relaying"
    - "sum rate maximized resource allocation in multiple df relays aided ofdm transmission"

Connected through hyperedge HE-4 (induced by source paper "power minimization for ofdm transmission with subcarrier pair based opportunistic df relaying"):
  with members:
    - "weighted sum rate maximization for downlink ofdma with subcarrier pair based opportunistic df relaying"
    - "sum rate maximized resource allocation in multiple df relays aided ofdm transmission"

Connected through hyperedge HE-5 (induced by source paper "on the scale algorithm for multiuser multicarrier power spectrum management"):
  with members:
    - "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)