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: "fixed parameter and approximation algorithms a new look"
  Abstract: A Fixed-Parameter Tractable (\FPT) $\rho$-approximation algorithm for a minimization (resp. maximization) parameterized problem $P$ is an FPT algorithm that, given an instance $(x, k)\in P$ computes a solution of cost at most $k \cdot \rho(k)$ (resp. $k/\rho(k)$) if a solution of cost at most (resp. at least) $k$ exists; otherwise the output can be arbitrary. For well-known intractable problems such as the W[1]-hard {Clique} and W[2]-hard {Set Cover} problems, the natural question is whether we can get any \FPT-approximation. It is widely believed that both {Clique} and {Set-Cover} admit no FPT $\rho$-approximation algorithm, for any increasing function $\rho$. Assuming standard conjectures such as the Exponential Time Hypothesis (ETH) \cite{eth-paturi} and the Projection Games Conjecture (PGC) \cite{r3}, we make the first progress towards proving this conjecture by showing that #R##N#1. Under the ETH and PGC, there exist constants $F_1, F_2 >0$ such that the {Set Cover} problem does not admit an FPT approximation algorithm with ratio $k^{F_1}$ in $2^{k^{F_2}}\cdot \text{poly}(N,M)$ time, where $N$ is the size of the universe and $M$ is the number of sets. #R##N#2. Unless $\NP\subseteq \SUBEXP$, for every $1> \delta > 0$ there exists a constant $F(\delta)>0$ such that {Clique} has no FPT cost approximation with ratio $k^{1-\delta}$ in $2^{k^{F}}\cdot \text{poly}(n)$ time, where $n$ is the number of vertices in the graph. #R##N#In the second part of the paper we consider various W[1]-hard problems such as {\dst}, {\dsf}, Directed Steiner Network and {\mec}. For all these problem we give polynomial time $f(\text{OPT})$-approximation algorithms for some small function $f$ (the largest approximation ratio we give is $\text{OPT}^2$).

Connected through hyperedge HE-1 (induced by source paper "parameterized approximation algorithms for directed steiner network problems"):
  with members:
    - "complexity of the steiner network problem with respect to the number of terminals"
    - "eth hardness of approximating 2 csps and directed steiner network"
    - "the complexity landscape of fixed parameter directed steiner network problems"
    - "from gap eth to fpt inapproximability clique dominating set and more"
    - "on subexponential parameterized algorithms for steiner tree and directed subset tsp on planar graphs"
    - "parameterized complexity and approximability of directed odd cycle transversal"
    - "subexponential parameterized algorithms for planar and apex minor free graphs via low treewidth pattern covering"
    - "almost polynomial ratio eth hardness of approximating densest k subgraph"

Connected through hyperedge HE-2 (induced by source paper "from gap eth to fpt inapproximability clique dominating set and more"):
  with members:
    - "completely inapproximable monotone and antimonotone parameterized problems"
    - "almost polynomial ratio eth hardness of approximating densest k subgraph"
    - "a birthday repetition theorem and complexity of approximating dense csps"
    - "how to refute a random csp"
    - "time approximation trade offs for inapproximable problems"
    - "eth hardness for densest k subgraph with perfect completeness"
    - "the constant inapproximability of the parameterized dominating set problem"
    - "lower bounds on the size of semidefinite programming relaxations"

Connected through hyperedge HE-3 (induced by source paper "parameterized approximation schemes for steiner trees with small number of steiner vertices"):
  with members:
    - "the complexity landscape of fixed parameter directed steiner network problems"
    - "the constant inapproximability of the parameterized dominating set problem"
    - "analytical approach to parallel repetition"

Connected through hyperedge HE-4 (induced by source paper "partitioning a graph into small pieces with applications to path transversal"):
  with members:
    - "linear kernels for edge deletion problems to immersion closed graph classes"
    - "almost polynomial ratio eth hardness of approximating densest k subgraph"
    - "hardness of approximation for h free edge modification problems"
    - "on the computational complexity of vertex integrity and component order connectivity"
    - "the complexity of approximating vertex expansion"
    - "polynomial integrality gaps for strong sdp relaxations of densest k subgraph"
    - "a new multilayered pcp and the hardness of hypergraph vertex cover"

Connected through hyperedge HE-5 (induced by source paper "fixed parameter approximability of boolean mincsps"):
  with members:
    - "completely inapproximable monotone and antimonotone parameterized problems"
    - "the complexity of weighted and unweighted csp"
    - "constraint satisfaction parameterized by solution size"
    - "the complexity of global cardinality constraints"

Connected through hyperedge HE-6 (induced by source paper "on directed steiner trees with multiple roots"):
  with members:
    - "parameterized complexity of directed steiner tree on sparse graphs"
    - "fpt algorithms for connected feedback vertex set"

Connected through hyperedge HE-7 (induced by source paper "time approximation trade offs for inapproximable problems"):
  with members:
    - "a constant factor approximation algorithm for the asymmetric traveling salesman problem"
    - "the constant inapproximability of the parameterized dominating set problem"
    - "effective resistance reducing flows spectrally thin trees and asymmetric tsp"
    - "analytical approach to parallel repetition"
    - "new inapproximability bounds for tsp"
    - "independent set induced matching and pricing connections and tight subexponential time approximation hardnesses"

Connected through hyperedge HE-8 (induced by source paper "the constant inapproximability of the parameterized dominating set problem"):
  with members:
    - "completely inapproximable monotone and antimonotone parameterized problems"
    - "the parameterized complexity of k biclique"
    - "deciding first order properties of nowhere dense graphs"
    - "fixed parameter inapproximability for clique and setcover in time super exponential in opt"
    - "analytical approach to parallel repetition"

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)