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: "riot i o efficient numerical computing without sql"
  Abstract: R is a numerical computing environment that is widely popular for statistical data analysis. Like many such environments, R performs poorly for large datasets whose sizes exceed that of physical memory. We present our vision of RIOT (R with I/O Transparency), a system that makes R programs I/O-efficient in a way transparent to the users. We describe our experience with RIOT-DB, an initial prototype that uses a relational database system as a backend. Despite the overhead and inadequacy of generic database systems in handling array data and numerical computation, RIOT-DB significantly outperforms R in many large-data scenarios, thanks to a suite of high-level, inter-operation optimizations that integrate seamlessly into R. While many techniques in RIOT are inspired by databases (and, for RIOT-DB, realized by a database system), RIOT users are insulated from anything database related. Compared with previous approaches that require users to learn new languages and rewrite their programs to interface with a database, RIOT will, we believe, be easier to adopt by the majority of the R users.

Connected through hyperedge HE-1 (induced by source paper "keystoneml optimizing pipelines for large scale advanced analytics"):
  with members:
    - "revisiting distributed synchronous sgd"
    - "youtube 8m a large scale video classification benchmark"
    - "caffe con troll shallow ideas to speed up deep learning"
    - "inferring networks of substitutable and complementary products"
    - "mllib machine learning in apache spark"
    - "rethinking the inception architecture for computer vision"
    - "dimmwitted a study of main memory statistical analytics"
    - "fast training of convolutional networks through ffts"

Connected through hyperedge HE-2 (induced by source paper "efficient iterative processing in the scidb parallel array engine"):
  with members:
    - "rex recursive delta based data centric computation"
    - "spinning fast iterative data flows"

Connected through hyperedge HE-3 (induced by source paper "linview incremental view maintenance for complex analytical queries"):
  with members:
    - "the madlib analytics library or mad skills the sql"
    - "dbtoaster higher order delta processing for dynamic frequently fresh views"
    - "rex recursive delta based data centric computation"

Connected through hyperedge HE-4 (induced by source paper "formal representation of the ss db benchmark and experimental evaluation in extascid"):
  with members:
    - "a survey on array storage query languages and systems"

Connected through hyperedge HE-5 (induced by source paper "optimizing i o for big array analytics"):
  with members:
    - "efficient and extensible algorithms for multi query optimization"

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)