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: "undefined by data a survey of big data definitions"
  Abstract: The term big data has become ubiquitous. Owing to a shared origin between academia, industry and the media there is no single unified definition, and various stakeholders provide diverse and often contradictory definitions. The lack of a consistent definition introduces ambiguity and hampers discourse relating to big data. This short paper attempts to collate the various definitions which have gained some degree of traction and to furnish a clear and concise definition of an otherwise ambiguous term.

Connected through hyperedge HE-1 (induced by source paper "deep unified multimodal embeddings for understanding both content and users in social media networks"):
  with members:
    - "integrating text and image determining multimodal document intent in instagram posts"
    - "align2ground weakly supervised phrase grounding guided by image caption alignment"
    - "universal dependency parsing from scratch"
    - "deep learning based recommender system a survey and new perspectives"
    - "exploring the limits of weakly supervised pretraining"
    - "a comprehensive survey of deep learning for image captioning"
    - "bert pre training of deep bidirectional transformers for language understanding"
    - "attributed social network embedding"

Connected through hyperedge HE-2 (induced by source paper "performance optimization of mapreduce based apriori algorithm on hadoop cluster"):
  with members:
    - "review of apriori based algorithms on mapreduce framework"
    - "observations on factors affecting performance of mapreduce based apriori on hadoop cluster"
    - "mining association rules in various computing environments a survey"

Connected through hyperedge HE-3 (induced by source paper "review and analysis of networking challenges in cloud computing"):
  with members:
    - "security and privacy issues of big data"
    - "resource allocation in a network based cloud computing environment design challenges"
    - "a survey of smart data pricing past proposals current plans and future trends"
    - "a taxonomy and survey of energy efficient data centers and cloud computing systems"

Connected through hyperedge HE-4 (induced by source paper "the effects of data quality on the analysis of corporate board interlock networks"):
  with members:
    - "where is the global corporate elite a large scale network study of local and nonlocal interlocking directorates"
    - "centrality in the global network of corporate control"
    - "matching entities across online social networks"

Connected through hyperedge HE-5 (induced by source paper "observations on factors affecting performance of mapreduce based apriori on hadoop cluster"):
  with members:
    - "performance analysis of apriori algorithm with different data structures on hadoop cluster"

Connected through hyperedge HE-6 (induced by source paper "intelligent management and efficient operation of big data"):
  with members:
    - "software defined networking a comprehensive survey"
    - "a deep architecture for semantic parsing"
    - "twitter mood predicts the stock market"

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.DB(Databases)