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: "improved purely additive fault tolerant spanners"
  Abstract: Let $G$ be an unweighted $n$-node undirected graph. A \emph{$\beta$-additive spanner} of $G$ is a spanning subgraph $H$ of $G$ such that distances in $H$ are stretched at most by an additive term $\beta$ w.r.t. the corresponding distances in $G$. A natural research goal related with spanners is that of designing \emph{sparse} spanners with \emph{low} stretch. #R##N#In this paper, we focus on \emph{fault-tolerant} additive spanners, namely additive spanners which are able to preserve their additive stretch even when one edge fails. We are able to improve all known such spanners, in terms of either sparsity or stretch. In particular, we consider the sparsest known spanners with stretch $6$, $28$, and $38$, and reduce the stretch to $4$, $10$, and $14$, respectively (while keeping the same sparsity). #R##N#Our results are based on two different constructions. On one hand, we show how to augment (by adding a \emph{small} number of edges) a fault-tolerant additive \emph{sourcewise spanner} (that approximately preserves distances only from a given set of source nodes) into one such spanner that preserves all pairwise distances. On the other hand, we show how to augment some known fault-tolerant additive spanners, based on clustering techniques. This way we decrease the additive stretch without any asymptotic increase in their size. We also obtain improved fault-tolerant additive spanners for the case of one vertex failure, and for the case of $f$ edge failures.

Connected through hyperedge HE-1 (induced by source paper "graph spanners a tutorial review"):
  with members:
    - "near additive spanners and near exact hopsets a unified view"
    - "some general structure for extremal sparsification problems"
    - "weighted additive spanners"
    - "near additive spanners in low polynomial deterministic congest time"
    - "multi level graph sketches via single level solvers"
    - "almost shortest paths and pram distance oracles in weighted graphs"
    - "an fpt algorithm for minimum additive spanner problem"
    - "distributed construction of light networks"

Connected through hyperedge HE-2 (induced by source paper "hardness approximability and fixed parameter tractability of the clustered shortest path tree problem"):
  with members:
    - "optimal number of cluster head selection for efficient distribution of sources in wsns"

Connected through hyperedge HE-3 (induced by source paper "preserving distances in very faulty graphs"):
  with members:
    - "connectivity oracles for graphs subject to vertex failures"
    - "a hierarchy of lower bounds for sublinear additive spanners"
    - "linear size distance preservers"
    - "dual failure resilient bfs structure"
    - "better distance preservers and additive spanners"
    - "the 4 3 additive spanner exponent is tight"
    - "fault tolerant approximate shortest path trees"
    - "fault tolerant approximate bfs structures"

Connected through hyperedge HE-4 (induced by source paper "optimal vertex fault tolerant spanners for fixed stretch"):
  with members:
    - "preserving distances in very faulty graphs"
    - "connectivity oracles for graphs subject to vertex failures"
    - "multiple edge fault tolerant approximate shortest path trees"
    - "improved distance sensitivity oracles via tree partitioning"
    - "compact and fast sensitivity oracles for single source distances"
    - "dual failure resilient bfs structure"
    - "fault tolerant approximate shortest path trees"
    - "fault tolerant approximate bfs structures"

Connected through hyperedge HE-5 (induced by source paper "near optimal sized weight tolerant subgraph for single source shortest path"):
  with members:
    - "multiple edge fault tolerant approximate shortest path trees"
    - "an efficient strongly connected components algorithm in the fault tolerant model"
    - "a hierarchy of lower bounds for sublinear additive spanners"
    - "dual failure resilient bfs structure"
    - "the 4 3 additive spanner exponent is tight"
    - "fault tolerant approximate shortest path trees"
    - "fault tolerant approximate bfs structures"
    - "vertex fault tolerant additive spanners"

Connected through hyperedge HE-6 (induced by source paper "multiple source dual fault tolerant bfs trees"):
  with members:
    - "multiple edge fault tolerant approximate shortest path trees"
    - "dynamic dfs in undirected graphs breaking the o m barrier"
    - "dual failure resilient bfs structure"
    - "fault tolerant approximate bfs structures"
    - "vertex fault tolerant additive spanners"
    - "sparse fault tolerant bfs trees"
    - "fault tolerant spanners better and simpler"

Connected through hyperedge HE-7 (induced by source paper "effective edge fault tolerant single source spanners via best or good swap edges"):
  with members:
    - "sensitivity analysis of minimum spanning trees in sub inverse ackermann time"
    - "fault tolerant approximate shortest path trees"
    - "fault tolerant spanners better and simpler"

Connected through hyperedge HE-8 (induced by source paper "connectivity oracles for graphs subject to vertex failures"):
  with members:
    - "dynamic minimum spanning forest with subpolynomial worst case update time"
    - "improved algorithms for maintaining dfs tree in undirected graphs"
    - "fully dynamic connectivity in o log n log log n 2 amortized expected time"
    - "faster randomized worst case update time for dynamic subgraph connectivity"
    - "dynamic dfs in undirected graphs breaking the o m barrier"
    - "incremental and fully dynamic subgraph connectivity for emergency planning"
    - "faster online matrix vector multiplication"
    - "unifying and strengthening hardness for dynamic problems via the online matrix vector multiplication conjecture"

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)