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: "google or google dissecting the evolution of the new osn in its first year"
  Abstract: In the era when Facebook and Twitter dominate the market for social media, Google has introduced Google+ (G+) and reported a significant growth in its size while others called it a ghost town. This begs the question that "whether G+ can really attract a significant number of connected and active users despite the dominance of Facebook and Twitter?". #R##N#This paper tackles the above question by presenting a detailed characterization of G+ based on large scale measurements. We identify the main components of G+ structure, characterize the key features of their users and their evolution over time. We then conduct detailed analysis on the evolution of connectivity and activity among users in the largest connected component (LCC) of G+ structure, and compare their characteristics with other major OSNs. We show that despite the dramatic growth in the size of G+, the relative size of LCC has been decreasing and its connectivity has become less clustered. While the aggregate user activity has gradually increased, only a very small fraction of users exhibit any type of activity. To our knowledge, our study offers the most comprehensive characterization of G+ based on the largest collected data sets.

Connected through hyperedge HE-1 (induced by source paper "understanding service integration of online social networks a data driven study"):
  with members:
    - "xgboost a scalable tree boosting system"
    - "snap a general purpose network analysis and graph mining library"
    - "studying social networks at scale macroscopic anatomy of the twitter social graph"
    - "social bootstrapping how pinterest and last fm social communities benefit by borrowing links from facebook"
    - "multi scale dynamics in a massive online social network"
    - "the anatomy of the facebook social graph"

Connected through hyperedge HE-2 (induced by source paper "characterization of cross posting activity for professional users across facebook twitter and google"):
  with members:
    - "mytweet via instagram exploring user behaviour across multiple social networks"
    - "social bootstrapping how pinterest and last fm social communities benefit by borrowing links from facebook"
    - "the anatomy of the facebook social graph"
    - "four degrees of separation"

Connected through hyperedge HE-3 (induced by source paper "evolution of directed triangle motifs in the google osn"):
  with members:
    - "degree relations of triangles in real world networks and graph models"
    - "evolution of social attribute networks measurements modeling and implications using google"
    - "multigraph sampling of online social networks"
    - "systematic topology analysis and generation using degree correlations"

Connected through hyperedge HE-4 (induced by source paper "wisdom of the crowd or wisdom of a few an analysis of users content generation"):
  with members:
    - "from amateurs to connoisseurs modeling the evolution of user expertise through online reviews"
    - "influence and passivity in social media"

Connected through hyperedge HE-5 (induced by source paper "reciprocity in social networks with capacity constraints"):
  with members:
    - "reconstructing 3 colored grids from horizontal and vertical projections is np hard"

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.SI(Social and Information Networks)