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: "truthful mechanisms for combinatorial allocation of electric power in alternating current electric systems for smart grid"
  Abstract: Traditional studies of combinatorial auctions often only consider linear constraints. The rise of smart grid presents a new class of auctions, characterized by quadratic constraints. This article studies the complex-demand knapsack problem, in which the demands are complex valued and the capacity of supplies is described by the magnitude of total complex-valued demand. This naturally captures the power constraints in alternating current electric systems. In this article, we provide a more complete study and generalize the problem to the multi-minded version, beyond the previously known f12-approximation algorithm for only a subclass of the problem. More precisely, we give a truthful polynomial-time approximation scheme (PTAS) for the case φ e l0,fπ2 − Δr and a truthful fully polynomial-time approximation scheme (FPTAS), which fully optimizes the objective function but violates the capacity constraint by at most (1 + e), for the case φ e (fπ2, π − Δr, where φ is the maximum argument of any complex-valued demand and e, Δ > 0 are arbitrarily small constants. We complement these results by showing that, unless PeNP, neither a PTAS for the case φ e (fπ2, π − Δr nor any bi-criteria approximation algorithm with polynomial guarantees for the case when p is arbitrarily close to π (that is, when Δ is arbitrarily close to 0) can exist.

Connected through hyperedge HE-1 (induced by source paper "combinatorial optimization of ac optimal power flow with discrete demands in radial networks"):
  with members:
    - "optimal power flow with inelastic demands for demand response in radial distribution networks"
    - "complex demand knapsack problems and incentives in ac power systems"

Connected through hyperedge HE-2 (induced by source paper "complex demand scheduling problem with application in smart grid"):
  with members:
    - "combinatorial optimization of ac optimal power flow with discrete demands in radial networks"
    - "optimal power flow with inelastic demands for demand response in radial distribution networks"
    - "online algorithm for demand response with inelastic demands and apparent power constraint"
    - "truthful mechanisms for combinatorial ac electric power allocation"
    - "complex demand knapsack problems and incentives in ac power systems"
    - "a mazing 2 eps approximation for unsplittable flow on a path"
    - "vector bin packing with multiple choice"

Connected through hyperedge HE-3 (induced by source paper "optimal power flow with inelastic demands for demand response in radial distribution networks"):
  with members:
    - "ac feasibility on tree networks is np hard"
    - "truthful mechanisms for combinatorial ac electric power allocation"
    - "complex demand knapsack problems and incentives in ac power systems"

Connected through hyperedge HE-4 (induced by source paper "assessing the privacy cost in centralized event based demand response for microgrids"):
  with members:
    - "privately solving linear programs"
    - "calibrating data to sensitivity in private data analysis"
    - "a learning theory approach to non interactive database privacy"
    - "differentially private combinatorial optimization"
    - "what can we learn privately"

Connected through hyperedge HE-5 (induced by source paper "online algorithm for demand response with inelastic demands and apparent power constraint"):
  with members:
    - "optimal power flow with inelastic demands for demand response in radial distribution networks"
    - "cost minimizing online algorithms for energy storage management with worst case guarantee"
    - "online algorithms for information aggregation from distributed and correlated sources"
    - "truthful mechanisms for combinatorial ac electric power allocation"
    - "complex demand knapsack problems and incentives in ac power systems"
    - "online energy generation scheduling for microgrids with intermittent energy sources and co generation"

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.GT(Computer Science and Game Theory)