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: "nearest neighbor based clustering algorithm for large data sets"
  Abstract: Clustering is an unsupervised learning technique in which data or objects are grouped into sets based on some similarity measure. Most of the clustering algorithms assume that the main memory is infinite and can accommodate the complete set of patterns. In reality, many applications give rise to a large set of patterns which does not fit in the main memory. When the data set is too large, much of the data are stored in the secondary memory. Input/outputs (I/O) from the disk are the major bottlenecks in designing efficient clustering algorithms for large data sets. Different designing techniques have been used to design clustering algorithms for large data sets. External memory algorithm is one class of algorithms which can be used for large data sets. These algorithms exploit the hierarchical memory structure of the computers by incorporating locality of reference directly in the algorithm. This paper contributes towards designing clustering algorithms in the external memory model (proposed by Aggarwal and Vitter) to make the algorithms scalable. In this paper, it is shown that the Shared near neighbors algorithm is not I/O efficient since the computational complexity and the I/O complexity both are same and high. The algorithm is redesigned in the external memory model reducing its I/O complexity without any change in its computational complexity. We substantiate the theoretical analysis by showing the performance of the algorithms with their traditional counterpart by implementing in STXXL library.

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)