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: "social welfare and profit maximization from revealed preferences"
  Abstract: Consider the seller's problem of finding "optimal" prices for her (divisible) goods when faced with a set of consumers, given that she can only observe their purchased bundles at set prices, i.e., access to only revealed preferences (demand oracle). We study both social welfare and profit maximization under this setting, assuming concave valuation function of consumers and convex production cost function of the seller, standard assumptions in economics. #R##N#Recent series of works (Roth et al., 2016, 2017) studied this problem for various special cases of valuation and cost functions, while making no assumption on the demand oracle. In this work, for social-welfare maximization, we obtain a natural interpretation of the revealed preference feedback in the dual optimization problem, and thereby obtain a simple gradient based algorithm. This simplifies and improves on (Roth et al., 2016, 2017) at least by a quadratic factor in terms of query complexity. #R##N#Second, we study social-welfare maximization under the online setting, where consumers arrive one-by-one in a {\em random order} a.k.a. secretary model. For the case where consumer valuation can be arbitrary continuous function, we design a price posting mechanism that achieves average expected social welfare up to an additive factor of $\frac{1}{\sqrt{m}}$ of maximum social welfare, where $m$ is the number of consumers. #R##N#Third, for the profit maximization, we obtain the first FPTAS when valuation and cost functions are separable, with a matching lower bound. For the non-separable case we show that no PTAS exists, even when only cost function is non-separable.

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)