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: "on the closest string and substring problems"
  Abstract: The problem of finding a center string that is `close' to every given string arises and has many applications in computational biology and coding theory. This problem has two versions: the Closest String problem and the Closest Substring problem. Assume that we are given a set of strings ${\cal S}=\{s_1, s_2, ..., s_n\}$ of strings, say, each of length $m$. The Closest String problem asks for the smallest $d$ and a string $s$ of length $m$ which is within Hamming distance $d$ to each $s_i\in {\cal S}$. This problem comes from coding theory when we are looking for a code not too far away from a given set of codes. The problem is NP-hard. Berman et al give a polynomial time algorithm for constant $d$. For super-logarithmic $d$, Ben-Dor et al give an efficient approximation algorithm using linear program relaxation technique. The best polynomial time approximation has ratio 4/3 for all $d$ given by Lanctot et al and Gasieniec et al. The Closest Substring problem looks for a string $t$ which is within Hamming distance $d$ away from a substring of each $s_i$. This problem only has a $2- \frac{2}{2|\Sigma|+1}$ approximation algorithm previously Lanctot et al and is much more elusive than the Closest String problem, but it has many applications in finding conserved regions, genetic drug target identification, and genetic probes in molecular biology. Whether there are efficient approximation algorithms for both problems are major open questions in this area. We present two polynomial time approxmation algorithms with approximation ratio $1+ \epsilon$ for any small $\epsilon$ to settle both questions.

Connected through hyperedge HE-1 (induced by source paper "on clustering incomplete data"):
  with members:
    - "parameterized k clustering the distance matters"
    - "approximation schemes for low rank binary matrix approximation problems"
    - "parameterized algorithms for the matrix completion problem"
    - "approximation algorithms for stochastic clustering"
    - "parameterized low rank binary matrix approximation"
    - "independence clustering without a matrix"
    - "dispersion on trees"
    - "mapreduce and streaming algorithms for diversity maximization in metric spaces of bounded doubling dimension"

Connected through hyperedge HE-2 (induced by source paper "low rank binary matrix approximation in column sum norm"):
  with members:
    - "approximation schemes for low rank binary matrix approximation problems"
    - "on the complexity of robust pca and l1 norm low rank matrix approximation"
    - "parameterized low rank binary matrix approximation"
    - "lower bounds for approximation schemes for closest string"
    - "on low rank approximation of binary matrices"
    - "sketching as a tool for numerical linear algebra"
    - "randomized algorithms for matrices and data"

Connected through hyperedge HE-3 (induced by source paper "on computing a center persistence diagram"):
  with members:
    - "approximating k ell center clustering for curves"
    - "approximate nearest neighbors in the space of persistence diagrams"
    - "geometry helps to compare persistence diagrams"

Connected through hyperedge HE-4 (induced by source paper "slightly superexponential parameterized problems"):
  with members:
    - "parameterized vertex deletion problems for hereditary graph classes with a block property"
    - "linear recognition of almost interval graphs"
    - "on the computational complexity of vertex integrity and component order connectivity"
    - "solving connectivity problems parameterized by treewidth in single exponential time"
    - "problems parameterized by treewidth tractable in single exponential time a logical approach"
    - "bandwidth and distortion revisited"
    - "planar subgraph isomorphism revisited"
    - "randomized algorithms for the loop cutset problem"

Connected through hyperedge HE-5 (induced by source paper "hardness of consensus problems for circular strings and time series averaging"):
  with members:
    - "on the hardness of computing an average curve"
    - "nonsmooth analysis and subgradient methods for averaging in dynamic time warping spaces"
    - "exact mean computation in dynamic time warping spaces"
    - "dynamic time warping and geometric edit distance breaking the quadratic barrier"
    - "quadratic conditional lower bounds for string problems and dynamic time warping"

Connected through hyperedge HE-6 (induced by source paper "tight hardness results for consensus problems on circular strings and time series"):
  with members:
    - "on the hardness of computing an average curve"
    - "nonsmooth analysis and subgradient methods for averaging in dynamic time warping spaces"
    - "exact mean computation in dynamic time warping spaces"
    - "dynamic time warping and geometric edit distance breaking the quadratic barrier"
    - "quadratic conditional lower bounds for string problems and dynamic time warping"

Connected through hyperedge HE-7 (induced by source paper "combinatorial n fold integer programming and applications"):
  with members:
    - "a parameterized strongly polynomial algorithm for block structured integer programs"
    - "on integer programming and convolution"
    - "scheduling meets n fold integer programming"
    - "the complexity landscape of decompositional parameters for ilp"
    - "proximity results and faster algorithms for integer programming using the steinitz lemma"
    - "simplified algorithmic metatheorems beyond mso treewidth and neighborhood diversity"
    - "voting and bribing in single exponential time"
    - "about the structure of the integer cone and its application to bin packing"

Connected through hyperedge HE-8 (induced by source paper "approximation and parameterized complexity of minimax approval voting"):
  with members:
    - "slightly superexponential parameterized problems"
    - "finding a collective set of items from proportional multirepresentation to group recommendation"
    - "parameterized algorithmics for computational social choice nine research challenges"

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.CE(Computational Engineering, Finance, and Science)