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: "dynamic web file format transformations with grace"
  Abstract: Web accessible content stored in obscure, unpopular or ob- solete formats represents a significant problem for digital preservation. The file formats that encode web content represent the implicit and ex- plicit choices of web site maintainers at a particular point in time. Older file formats that have fallen out of favor are obviously a problem, but so are new file formats that have not yet been fully supported by browsers. Often browsers use plug-in software for displaying old and new formats, but plug-ins can be difficult to find, install and replicate across all envi- ronments that one may use. We introduce Grace, an http proxy server that transparently converts browser-incompatible and obsolete web con- tent into web content that a browser is able to display without the use of plug-ins. Grace is configurable on a per user basis and can be expanded to provide an array of conversion services. We illustrate how the Grace prototype transforms several image formats (XBM, PNG with various alpha channels, and JPEG 2000) so they are viewable in Internet Ex- plorer.

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.DL(Digital Libraries)