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: "preventing unraveling in social networks gets harder"
  Abstract: The behavior of users in social networks is often observed to be affected by the actions of their friends. Bhawalkar et al. \cite{bhawalkar-icalp} introduced a formal mathematical model for user engagement in social networks where each individual derives a benefit proportional to the number of its friends which are engaged. Given a threshold degree $k$ the equilibrium for this model is a maximal subgraph whose minimum degree is $\geq k$. However the dropping out of individuals with degrees less than $k$ might lead to a cascading effect of iterated withdrawals such that the size of equilibrium subgraph becomes very small. To overcome this some special vertices called "anchors" are introduced: these vertices need not have large degree. Bhawalkar et al. \cite{bhawalkar-icalp} considered the \textsc{Anchored $k$-Core} problem: Given a graph $G$ and integers $b, k$ and $p$ do there exist a set of vertices $B\subseteq H\subseteq V(G)$ such that $|B|\leq b, |H|\geq p$ and every vertex $v\in H\setminus B$ has degree at least $k$ is the induced subgraph $G[H]$. They showed that the problem is NP-hard for $k\geq 2$ and gave some inapproximability and fixed-parameter intractability results. In this paper we give improved hardness results for this problem. In particular we show that the \textsc{Anchored $k$-Core} problem is W[1]-hard parameterized by $p$, even for $k=3$. This improves the result of Bhawalkar et al. \cite{bhawalkar-icalp} (who show W[2]-hardness parameterized by $b$) as our parameter is always bigger since $p\geq b$. Then we answer a question of Bhawalkar et al. \cite{bhawalkar-icalp} by showing that the \textsc{Anchored $k$-Core} problem remains NP-hard on planar graphs for all $k\geq 3$, even if the maximum degree of the graph is $k+2$. Finally we show that the problem is FPT on planar graphs parameterized by $b$ for all $k\geq 7$.

Connected through hyperedge HE-1 (induced by source paper "building large k cores from sparse graphs"):
  with members:
    - "a survey of parameterized algorithms and the complexity of edge modification"
    - "finding even subgraphs even faster"
    - "editing to a connected graph of given degrees"
    - "parameterized complexity of the anchored k core problem for directed graphs"
    - "editing to a graph of given degrees"
    - "understanding edge connectivity in the internet through core decomposition"
    - "k core decomposition of internet graphs hierarchies self similarity and measurement biases"

Connected through hyperedge HE-2 (induced by source paper "k core minimization a game theoretic approach"):
  with members:
    - "towards scalable network delay minimization"
    - "boosting information spread an algorithmic approach"
    - "social resilience in online communities the autopsy of friendster"
    - "parameterized exact and approximation algorithms for maximum k set cover and related satisfiability problems"
    - "graph measures and network robustness"
    - "a model of internet topology using k shell decomposition"

Connected through hyperedge HE-3 (induced by source paper "k core maximization through edge additions"):
  with members:
    - "k core minimization a game theoretic approach"
    - "a fast order based approach for core maintenance"
    - "an o m algorithm for cores decomposition of networks"

Connected through hyperedge HE-4 (induced by source paper "a parameterized complexity view on collapsing k cores"):
  with members:
    - "linear time kernelization for feedback vertex set"
    - "social resilience in online communities the autopsy of friendster"
    - "parameterized complexity of the anchored k core problem for directed graphs"
    - "faster deterministic feedback vertex set"

Connected through hyperedge HE-5 (induced by source paper "when engagement meets similarity efficient k r core computation on social networks"):
  with members:
    - "i o efficient core graph decomposition at web scale"
    - "towards realistic team formation in social networks based on densest subgraphs"
    - "keep your friends close and your facebook friends closer a multiplex network approach to the analysis of offline and online social ties"
    - "locally estimating core numbers"
    - "geo social group queries with minimum acquaintance constraint"
    - "parameterized complexity of the anchored k core problem for directed graphs"
    - "community detection in networks with node attributes"
    - "mining attribute structure correlated patterns in large attributed graphs"

Connected through hyperedge HE-6 (induced by source paper "parameterized complexity of the anchored k core problem for directed graphs"):
  with members:
    - "fixed parameter tractability of directed multiway cut parameterized by the size of the cutset"

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.SI(Social and Information Networks)