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 bounds for online preemptive matching"
  Abstract: When designing a preemptive online algorithm for the maximum matching problem, we wish to maintain a valid matching M while edges of the underlying graph are presented one after the other. When presented with an edge e, the algorithm should decide whether to augment the matching M by adding e (in which case e may be removed later on) or to keep M in its current form without adding e (in which case e is lost for good). The objective is to eventually hold a matching M with maximum weight. #R##N#The main contribution of this paper is to establish new lower and upper bounds on the competitive ratio achievable by preemptive online algorithms: #R##N#1. We provide a lower bound of 1+ln 2~1.693 on the competitive ratio of any randomized algorithm for the maximum cardinality matching problem, thus improving on the currently best known bound of e/(e-1)~1.581 due to Karp, Vazirani, and Vazirani [STOC'90]. #R##N#2. We devise a randomized algorithm that achieves an expected competitive ratio of 5.356 for maximum weight matching. This finding demonstrates the power of randomization in this context, showing how to beat the tight bound of 3 +2\sqrt{2}~5.828 for deterministic algorithms, obtained by combining the 5.828 upper bound of McGregor [APPROX'05] and the recent 5.828 lower bound of Varadaraja [ICALP'11].

Connected through hyperedge HE-1 (induced by source paper "prophet inequality for bipartite matching merits of being simple and non adaptive"):
  with members:
    - "near optimal online algorithms and fast approximation algorithms for resource allocation problems"
    - "tight competitive ratios of classic matching algorithms in the fully online model"
    - "how to match when all vertices arrive online"
    - "maximizing efficiency in dynamic matching markets"
    - "makespan minimization via posted prices"
    - "prophet inequalities made easy stochastic optimization by pricing non stochastic inputs"
    - "beyond matroids secretary problem and prophet inequality with general constraints"
    - "online contention resolution schemes"

Connected through hyperedge HE-2 (induced by source paper "online stochastic matching with edge arrivals"):
  with members:
    - "beating greedy for stochastic bipartite matching"
    - "online matching with general arrivals"
    - "prophet inequality for bipartite matching merits of being simple and non adaptive"
    - "tight competitive ratios of classic matching algorithms in the fully online model"
    - "how to match when all vertices arrive online"
    - "online matroid intersection beating half for random arrival"
    - "improved approximation algorithms for stochastic matching"
    - "buyback problem approximate matroid intersection with cancellation costs"

Connected through hyperedge HE-3 (induced by source paper "online matching with general arrivals"):
  with members:
    - "tight bounds for online edge coloring"
    - "tight competitive ratios of classic matching algorithms in the fully online model"
    - "how to match when all vertices arrive online"
    - "online vertex weighted bipartite matching beating 1 1 e with random arrivals"
    - "an economic based analysis of ranking for online bipartite matching"
    - "tighter bounds for online bipartite matching"
    - "online lower bounds via duality"
    - "maximum matching on trees in the online preemptive and the incremental dynamic graph models"

Connected through hyperedge HE-4 (induced by source paper "online maximum matching with recourse"):
  with members:
    - "relaxing the irrevocability requirement for online graph algorithms"
    - "online bipartite matching with amortized o log 2 n replacements"
    - "online steiner tree with deletions"
    - "the power of deferral maintaining a constant competitive steiner tree online"
    - "buyback problem approximate matroid intersection with cancellation costs"

Connected through hyperedge HE-5 (induced by source paper "how to match when all vertices arrive online"):
  with members:
    - "on randomized algorithms for matching in the online preemptive model"
    - "ranking on arbitrary graphs rematch via continuous lp with monotone and boundary condition constraints"
    - "buyback problem approximate matroid intersection with cancellation costs"
    - "online vertex weighted bipartite matching and single bid budgeted allocations"

Connected through hyperedge HE-6 (induced by source paper "on conceptually simple algorithms for variants of online bipartite matching"):
  with members:
    - "an experimental study of algorithms for online bipartite matching"
    - "on the limitations of deterministic de randomizations for online bipartite matching and max sat"
    - "computing maximum flow with augmenting electrical flows"
    - "on the power of advice and randomization for online bipartite matching"
    - "new algorithms better bounds and a novel model for online stochastic matching"
    - "deterministic algorithms for submodular maximization problems"
    - "greedy matching guarantees and limitations"
    - "greedy algorithms make efficient mechanisms"

Connected through hyperedge HE-7 (induced by source paper "online submodular maximization problem with vector packing constraint"):
  with members:
    - "online submodular maximization with preemption"
    - "online bipartite matching with decomposable weights"
    - "geometry of online packing linear programs"
    - "submodular function maximization via the multilinear relaxation and contention resolution schemes"
    - "online stochastic packing applied to display ad allocation"

Connected through hyperedge HE-8 (induced by source paper "relaxing the irrevocability requirement for online graph algorithms"):
  with members:
    - "online dominating set"
    - "advice complexity of the online induced subgraph problem"
    - "online steiner tree with deletions"
    - "improved approximation guarantees for weighted matching in the semi streaming model"

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)