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: "an improved isomorphism test for bounded tree width graphs"
  Abstract: We give a new fpt algorithm testing isomorphism of $n$-vertex graphs of tree width $k$ in time $2^{k\operatorname{polylog} (k)}\operatorname{poly} (n)$, improving the fpt algorithm due to Lokshtanov, Pilipczuk, Pilipczuk, and Saurabh (FOCS 2014), which runs in time $2^{\mathcal{O}(k^5\log k)}\operatorname{poly} (n)$. Based on an improved version of the isomorphism-invariant graph decomposition technique introduced by Lokshtanov et al., we prove restrictions on the structure of the automorphism groups of graphs of tree width $k$. Our algorithm then makes heavy use of the group theoretic techniques introduced by Luks (JCSS 1982) in his isomorphism test for bounded degree graphs and Babai (STOC 2016) in his quasipolynomial isomorphism test. In fact, we even use Babai's algorithm as a black box in one place. #R##N#We also give a second algorithm which, at the price of a slightly worse running time $2^{\mathcal{O}(k^2 \log k)}\operatorname{poly} (n)$, avoids the use of Babai's algorithm and, more importantly, has the additional benefit that it can also used as a canonization algorithm.

Connected through hyperedge HE-1 (induced by source paper "hypergraph isomorphism for groups with restricted composition factors"):
  with members:
    - "graph isomorphism in quasipolynomial time parameterized by treewidth"
    - "a faster isomorphism test for graphs of small degree"
    - "a unifying method for the design of algorithms canonizing combinatorial objects"
    - "graph isomorphism for unit square graphs"
    - "graph isomorphism in quasipolynomial time"
    - "graph isomorphism for bounded genus graphs in linear time"
    - "tight lower and upper bounds for the complexity of canonical colour refinement"
    - "isomorphism testing for graphs of bounded rank width"

Connected through hyperedge HE-2 (induced by source paper "computing the frechet distance of trees and graphs of bounded tree width"):
  with members:
    - "fixed parameter tractable canonization and isomorphism test for graphs of bounded treewidth"
    - "can we compute the similarity between surfaces"

Connected through hyperedge HE-3 (induced by source paper "graph isomorphism in quasipolynomial time parameterized by treewidth"):
  with members:
    - "hypergraph isomorphism for groups with restricted composition factors"
    - "a faster isomorphism test for graphs of small degree"
    - "a unifying method for the design of algorithms canonizing combinatorial objects"
    - "minimum circuit size graph isomorphism and related problems"
    - "canonizing graphs of bounded tree width in logspace"
    - "graph isomorphism in quasipolynomial time"
    - "graph isomorphism for bounded genus graphs in linear time"
    - "fixed parameter tractable canonization and isomorphism test for graphs of bounded treewidth"

Connected through hyperedge HE-4 (induced by source paper "canonisation and definability for graphs of bounded rank width"):
  with members:
    - "definable decompositions for graphs of bounded linear cliquewidth"
    - "the weisfeiler leman dimension of planar graphs is at most 3"
    - "computing with tangles"
    - "isomorphism testing for graphs of bounded rank width"
    - "fixed parameter tractable canonization and isomorphism test for graphs of bounded treewidth"
    - "structure theorem and isomorphism test for graphs with excluded topological subgraphs"
    - "capturing polynomial time on interval graphs"

Connected through hyperedge HE-5 (induced by source paper "normalizers and permutational isomorphisms in simply exponential time"):
  with members:
    - "a unifying method for the design of algorithms canonizing combinatorial objects"
    - "beating the generator enumeration bound for p group isomorphism"
    - "algorithms for group isomorphism via group extensions and cohomology"

Connected through hyperedge HE-6 (induced by source paper "graph isomorphism for h_1 h_2 free graphs an almost complete dichotomy"):
  with members:
    - "canonisation and definability for graphs of bounded rank width"
    - "a faster isomorphism test for graphs of small degree"
    - "clique width for graph classes closed under complementation"
    - "graph isomorphism for unit square graphs"
    - "induced minor free graphs isomorphism and clique width"
    - "bounding the clique width of h free chordal graphs"
    - "colouring diamond free graphs"
    - "isomorphism testing for graphs of bounded rank width"

Connected through hyperedge HE-7 (induced by source paper "a unifying method for the design of algorithms canonizing combinatorial objects"):
  with members:
    - "a faster isomorphism test for graphs of small degree"
    - "minimum circuit size graph isomorphism and related problems"
    - "polynomial time isomorphism test of groups that are tame extensions"
    - "isomorphism testing for graphs of bounded rank width"
    - "beating the generator enumeration bound for p group isomorphism"
    - "algorithms for group isomorphism via group extensions and cohomology"

Connected through hyperedge HE-8 (induced by source paper "a faster isomorphism test for graphs of small degree"):
  with members:
    - "graph isomorphism in quasipolynomial time"
    - "fixed parameter tractable canonization and isomorphism test for graphs of bounded treewidth"
    - "graph isomorphism for graph classes characterized by two forbidden induced subgraphs"
    - "structure theorem and isomorphism test for graphs with excluded topological subgraphs"

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.DS(Data Structures and Algorithms)