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: "tales of 34 iphone users how they change and why they are different"
  Abstract: We present results from a longitudinal study of 34 iPh-one 3GS users, called LiveLab. LiveLab collected unprecedented usage data through an in-device, programmable logger and several structured interviews with the participants throughout the study. We have four objectives in writing this paper: (i) share the findings with the research community; (ii) provide insights guiding the design of smartphone systems and applications; (iii) demonstrate the power of prudently designed longitudinal field studies and the power of advanced research methods; and (iv) raise important questions that the research community can help answer in a collaborative, multidisciplinary manner. #R##N#We show how the smartphone usage changes over the year and why the users are different (and similar) in their usage. In particular, our findings highlight application and web usage dynamics, the influence of socioeconomic status (SES) on usage, and the shortcomings of iPhone 3GS and its ecosystem. We further show that distinct classes of usage patterns exist, and these classes are best served by different phone designs, instead of the one-size-fits-all phone Apple provides. Our findings are significant not only for understanding smartphone users but also in guiding device and application development and optimizations. While we present novel results that can only be produced by a study of this nature, we also raise new research questions to be investigated by the mobile research community.

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.HC(Human-Computer Interaction)