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: "answering conjunctive queries under updates"
  Abstract: We consider the task of enumerating and counting answers to $k$-ary conjunctive queries against relational databases that may be updated by inserting or deleting tuples. We exhibit a new notion of q-hierarchical conjunctive queries and show that these can be maintained efficiently in the following sense. During a linear time preprocessing phase, we can build a data structure that enables constant delay enumeration of the query results; and when the database is updated, we can update the data structure and restart the enumeration phase within constant time. For the special case of self-join free conjunctive queries we obtain a dichotomy: if a query is not q-hierarchical, then query enumeration with sublinear$^\ast$ delay and sublinear update time (and arbitrary preprocessing time) is impossible. #R##N#For answering Boolean conjunctive queries and for the more general problem of counting the number of solutions of k-ary queries we obtain complete dichotomies: if the query's homomorphic core is q-hierarchical, then size of the the query result can be computed in linear time and maintained with constant update time. Otherwise, the size of the query result cannot be maintained with sublinear update time. All our lower bounds rely on the OMv-conjecture, a conjecture on the hardness of online matrix-vector multiplication that has recently emerged in the field of fine-grained complexity to characterise the hardness of dynamic problems. The lower bound for the counting problem additionally relies on the orthogonal vectors conjecture, which in turn is implied by the strong exponential time hypothesis. #R##N#$^\ast)$ By sublinear we mean $O(n^{1-\varepsilon})$ for some $\varepsilon>0$, where $n$ is the size of the active domain of the current database.

Connected through hyperedge HE-1 (induced by source paper "constant delay enumeration with fpt preprocessing for conjunctive queries of bounded submodular width"):
  with members:
    - "enumeration on trees under relabelings"
    - "answering fo mod queries under updates on bounded degree databases"
    - "covers of query results"
    - "constraint solving via fractional edge covers"
    - "compressed representations of conjunctive query results"
    - "answering ucqs under updates and in the presence of integrity constraints"
    - "what do shannon type inequalities submodular width and disjunctive datalog have to do with one another"
    - "tractable hypergraph properties for constraint satisfaction and conjunctive queries"

Connected through hyperedge HE-2 (induced by source paper "optimal algorithms for ranked enumeration of answers to full conjunctive queries"):
  with members:
    - "ranked enumeration of conjunctive query results"
    - "any k anytime top k tree pattern retrieval in labeled graphs"
    - "on functional aggregate queries with additive inequalities"
    - "on the enumeration complexity of unions of conjunctive queries"
    - "size bounds and query plans for relational joins"
    - "covers of query results"
    - "constraint solving via fractional edge covers"
    - "what do shannon type inequalities submodular width and disjunctive datalog have to do with one another"

Connected through hyperedge HE-3 (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"
    - "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"
    - "gym a multiround join algorithm in mapreduce"

Connected through hyperedge HE-4 (induced by source paper "ranked enumeration of conjunctive query results"):
  with members:
    - "any k anytime top k tree pattern retrieval in labeled graphs"
    - "answering fo mod queries under updates on bounded degree databases"
    - "size bounds and query plans for relational joins"
    - "compressed representations of conjunctive query results"
    - "skew strikes back new developments in the theory of join algorithms"
    - "fdb a query engine for factorised relational databases"
    - "optimal aggregation algorithms for middleware"

Connected through hyperedge HE-5 (induced by source paper "incremental techniques for large scale dynamic query processing"):
  with members:
    - "counting triangles under updates in worst case optimal time"
    - "answering fo mod queries under updates on bounded degree databases"
    - "incremental view maintenance with triple lock factorization benefits"
    - "answering ucqs under updates and in the presence of integrity constraints"
    - "linview incremental view maintenance for complex analytical queries"
    - "dbtoaster higher order delta processing for dynamic frequently fresh views"

Connected through hyperedge HE-6 (induced by source paper "conjunctive queries with theta joins under updates"):
  with members:
    - "incremental view maintenance with triple lock factorization benefits"
    - "aggregation and ordering in factorised databases"
    - "dbtoaster higher order delta processing for dynamic frequently fresh views"

Connected through hyperedge HE-7 (induced by source paper "constant delay enumeration for nondeterministic document spanners"):
  with members:
    - "enumeration on trees with tractable combined complexity and efficient updates"
    - "enumeration on trees under relabelings"
    - "constant delay algorithms for regular document spanners"
    - "answering fo mod queries under updates on bounded degree databases"
    - "a circuit based approach to efficient enumeration"
    - "document spanners for extracting incomplete information expressiveness and complexity"
    - "joining extractions of regular expressions"
    - "answering ucqs under updates and in the presence of integrity constraints"

Connected through hyperedge HE-8 (induced by source paper "enumeration on trees with tractable combined complexity and efficient updates"):
  with members:
    - "constant delay enumeration for nondeterministic document spanners"
    - "enumeration on trees under relabelings"
    - "constant delay algorithms for regular document spanners"
    - "answering fo mod queries under updates on bounded degree databases"
    - "a circuit based approach to efficient enumeration"
    - "enumeration complexity of conjunctive queries with functional dependencies"
    - "answering ucqs under updates and in the presence of integrity constraints"
    - "powers of tensors and fast matrix multiplication"

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)