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: "a lattice framework for pricing display ad options with the stochastic volatility underlying model"
  Abstract: Ad options are a recent development in online advertising which provide advertisers with greater flexibility related to buying their guaranteed deliveries in the future. In short, an ad option is a contract in which an online publisher (or search engine) grants an advertiser the right but not obligation to enter into transactions to purchase impressions or clicks from a specific online ad slot at a pre-specified price on a specific delivery date. Previous studies on the ad option pricing models are mostly restricted to the situation where the underlying price follows a geometric Brownian motion (GBM). However, it has been shown that GBM only happens in less than 20% of the stochastic movements of ad auction prices. In this paper, we address this issue by employing a stochastic volatility (SV) model to describe the evolution of the underlying price which does not rely on the assumption of GBM. The computational tractability is solved by approximating the SV model with a proposed censored binomial lattice. Our developments are validated by experiments with the real advertising data. We find that the SV model has a better fitness to the real adverting data; with the real data, we demonstrate that advertisers are able flexibly to manage their guaranteed deliveries by using the proposed options. We also demonstrate that publishers will have increased revenue when some of their inventories are sold via ad options.

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)