human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge is induced by one source paper and its member nodes are the cited papers.

Details of the hypergraph:
Center hyperedge (induced by source paper "complex demand scheduling problem with application in smart grid"):
  Abstract: Abstract   We consider the problem of scheduling complex-valued demands over a discretized time horizon. Given a set of users, each user is associated with a set of demands representing different power consumption preferences. A demand is represented by a complex number, a time interval, and a utility value obtained if it is satisfied. At each time slot, the magnitude of the total selected demands should not exceed a given generation capacity. This naturally captures the supply constraints in alternating current (AC) electric systems. In this paper, we consider maximizing the aggregate user utility subject to power supply limits over a time horizon. We present approximation algorithms characterized by the maximum angle ϕ between any two complex-valued demands. More precisely, a PTAS is presented for the case    ϕ  ∈  [  0  ,    π    2    ]   , a bi-criteria FPTAS for    ϕ  ∈  [  0  ,  π  -  e  ]    for any polynomially small e, assuming the number of time slots in the discretized time horizon is a constant. Furthermore, if the number of time slots is part of the input, we present a reduction to the real-valued unsplittable flow problem on a path with only a constant approximation ratio. Finally, we present a practical greedy algorithm for the single time slot case with an approximation ratio of      1    2    cos  ⁡    ϕ    2      and a running time complexity of only    O  (  N  log  ⁡  N  )   , N standing for the aggregate number of user demands, which can be implemented efficiently in practice.

Includes members:
  Member "combinatorial optimization of ac optimal power flow with discrete demands in radial networks":
    also connected through other hyperedges:
      (none)
  Member "optimal power flow with inelastic demands for demand response in radial distribution networks":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "combinatorial optimization of ac optimal power flow with discrete demands in radial networks")
  Member "truthful mechanisms for combinatorial allocation of electric power in alternating current electric systems for smart grid":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "combinatorial optimization of ac optimal power flow with discrete demands in radial networks")
  Member "online algorithm for demand response with inelastic demands and apparent power constraint":
    also connected through other hyperedges:
      (none)
  Member "truthful mechanisms for combinatorial ac electric power allocation":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "optimal power flow with inelastic demands for demand response in radial distribution networks")
  Member "complex demand knapsack problems and incentives in ac power systems":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "combinatorial optimization of ac optimal power flow with discrete demands in radial networks")
  Member "a mazing 2 eps approximation for unsplittable flow on a path":
    also connected through other hyperedges:
      (none)
  Member "vector bin packing with multiple choice":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "joint transmission in cellular networks with comp stability and scheduling algorithms")

Question: Please tell me which class the source paper 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.DS(Data Structures and Algorithms)