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: "gym a multiround join algorithm in mapreduce"
  Abstract: Multiround algorithms are now commonly used in distributed data processing systems, yet the extent to which algorithms can benefit from running more rounds is not well understood. This paper answers this question for a spectrum of rounds for the problem of computing the equijoin of $n$ relations. Specifically, given any query $Q$ with width $\w$, {\em intersection width} $\iw$, input size $\mathrm{IN}$, output size $\mathrm{OUT}$, and a cluster of machines with $M$ memory available per machine, we show that: #R##N#(1) $Q$ can be computed in $O(n)$ rounds with $O(n\frac{(\mathrm{IN}^{\w} + \mathrm{OUT})^2}{M})$ communication cost. #R##N#(2) $Q$ can be computed in $O(\log(n))$ rounds with $O(n\frac{(\mathrm{IN}^{\max(\w, 3\iw)} + \mathrm{OUT})^2}{M})$ communication cost. \end{itemize} Intersection width is a new notion of queries and generalized hypertree decompositions (GHDs) of queries we introduce to capture how connected the adjacent cyclic components of the GHDs are. #R##N#We achieve our first result by introducing a distributed and generalized version of Yannakakis's algorithm, called GYM. GYM takes as input any GHD of $Q$ with width $\w$ and depth $d$, and computes $Q$ in $O(d + \log(n))$ rounds and $O(n\frac{(\mathrm{IN}^{\w} + \mathrm{OUT})^2}{M})$ communication cost. We achieve our second result by showing how to construct GHDs of $Q$ with width $\max(\w, 3\iw)$ and depth $O(\log(n))$. We describe another technique to construct GHDs with longer widths and shorter depths, demonstrating a spectrum of tradeoffs one can make between communication and the number of rounds.

Connected through hyperedge HE-1 (induced by source paper "complexity analysis of general and fractional hypertree decompositions"):
  with members:
    - "hyperbench a benchmark and tool for hypergraphs and empirical findings"
    - "tree projections and constraint optimization problems fixed parameter tractability and parallel algorithms"
    - "size bounds and query plans for relational joins"
    - "constraint solving via fractional edge covers"
    - "an analytical study of large sparql query logs"
    - "old techniques for new join algorithms a case study in rdf processing"
    - "general and fractional hypertree decompositions hard and easy cases"
    - "myhill nerode methods for hypergraphs"

Connected through hyperedge HE-2 (induced by source paper "instance and output optimal parallel algorithms for acyclic joins"):
  with members:
    - "size bounds and query plans for relational joins"
    - "constraint solving via fractional edge covers"
    - "answering conjunctive queries under updates"
    - "worst case optimal algorithms for parallel query processing"
    - "what do shannon type inequalities submodular width and disjunctive datalog have to do with one another"
    - "it s all a matter of degree using degree information to optimize multiway joins"
    - "the input output complexity of triangle enumeration"
    - "skew in parallel query processing"

Connected through hyperedge HE-3 (induced by source paper "dependency weighted aggregation on factorized databases"):
  with members:
    - "constraint solving via fractional edge covers"
    - "hypergraph acyclicity and propositional model counting"
    - "structural tractability of counting of solutions to conjunctive queries"
    - "hypertree decompositions and tractable queries"
    - "a knowledge compilation map"

Connected through hyperedge HE-4 (induced by source paper "general and fractional hypertree decompositions hard and easy cases"):
  with members:
    - "size bounds and query plans for relational joins"
    - "constraint solving via fractional edge covers"
    - "an analytical study of large sparql query logs"
    - "old techniques for new join algorithms a case study in rdf processing"
    - "myhill nerode methods for hypergraphs"
    - "faq questions asked frequently"
    - "joins via geometric resolutions worst case and beyond"
    - "aggregation and ordering in factorised databases"

Connected through hyperedge HE-5 (induced by source paper "greedy strategies and larger islands of tractability for conjunctive queries and constraint satisfaction problems"):
  with members:
    - "constraint solving via fractional edge covers"
    - "flexible caching in trie joins"
    - "a quasi polynomial time partition oracle for graphs with an excluded minor"
    - "tree projections and structural decomposition methods minimality and game theoretic characterization"
    - "on the computational complexity of a game of cops and robbers"
    - "hybrid tractability of valued constraint problems"
    - "tractable hypergraph properties for constraint satisfaction and conjunctive queries"
    - "hypertree decompositions and tractable queries"

Connected through hyperedge HE-6 (induced by source paper "parallel evaluation of multi semi joins"):
  with members:
    - "handling skew in multiway joins in parallel processing"
    - "skew in parallel query processing"
    - "communication steps for parallel query processing"
    - "shark sql and rich analytics at scale"

Connected through hyperedge HE-7 (induced by source paper "scheduling mapreduce jobs under multi round precedences"):
  with members:
    - "scheduling mapreduce jobs and data shuffle on unrelated processors"

Connected through hyperedge HE-8 (induced by source paper "emptyheaded a relational engine for graph processing"):
  with members:
    - "size bounds and query plans for relational joins"
    - "snap a general purpose network analysis and graph mining library"
    - "aggregations over generalized hypertree decompositions"
    - "join processing for graph patterns an old dog with new tricks"
    - "faq questions asked frequently"
    - "simd compression and the intersection of sorted integers"
    - "eagr supporting continuous ego centric aggregate queries over large dynamic graphs"
    - "skew strikes back new developments in the theory of join algorithms"

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)