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: "optimal demand side management for joint privacy cost optimization with energy storage"
  Abstract: The smart meter (SM) privacy problem is addressed together with the cost of energy for the user. It is assumed that a storage device, e.g., an electrical battery, is available to the user, which can be utilized both to achieve privacy and to reduce the energy cost by modifying the energy consumption profile. Privacy is measured via the mean squared-error between the SM readings, which are reported to the utility provider (UP), and a target load; while time-of-use pricing is considered for energy cost calculation. The optimal trade-off between the achievable privacy and the energy cost is characterized by taking into account the limited capacity of the battery as well as the capability to sell energy to the UP. Extensive numerical simulations are presented to evaluate the performance of the proposed strategy for different system settings.

Connected through hyperedge HE-1 (induced by source paper "privacy aware smart metering progress and challenges"):
  with members:
    - "smart meter privacy via the trapdoor channel"
    - "privacy protecting energy management unit through model distribution predictive control"
    - "information theoretic privacy for smart metering systems with a rechargeable battery"
    - "privacy optimal strategies for smart metering systems with a rechargeable battery"
    - "smart meter privacy with an energy harvesting device and instantaneous power constraints"
    - "the uk dale dataset domestic appliance level electricity demand and whole house demand from five uk homes"
    - "smart meter privacy for multiple users in the presence of an alternative energy source"
    - "increasing smart meter privacy through energy harvesting and storage devices"

Connected through hyperedge HE-2 (induced by source paper "joint privacy cost optimization in smart electricity metering systems"):
  with members:
    - "privacy aware smart metering progress and challenges"
    - "privacy protecting energy management unit through model distribution predictive control"
    - "information theoretic privacy for smart metering systems with a rechargeable battery"
    - "the uk dale dataset domestic appliance level electricity demand and whole house demand from five uk homes"
    - "smart meter privacy for multiple users in the presence of an alternative energy source"

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)