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: "computing critical k tuples in power networks"
  Abstract: In this paper the problem of finding the sparsest (i.e., minimum cardinality) critical $k$-tuple including one arbitrarily specified measurement is considered. The solution to this problem can be used to identify weak points in the measurement set, or aid the placement of new meters. The critical $k$-tuple problem is a combinatorial generalization of the critical measurement calculation problem. Using topological network observability results, this paper proposes an efficient and accurate approximate solution procedure for the considered problem based on solving a minimum-cut (Min-Cut) problem and enumerating all its optimal solutions. It is also shown that the sparsest critical $k$-tuple problem can be formulated as a mixed integer linear programming (MILP) problem. This MILP problem can be solved exactly using available solvers such as CPLEX and Gurobi. A detailed numerical study is presented to evaluate the efficiency and the accuracy of the proposed Min-Cut and MILP calculations.

Connected through hyperedge HE-1 (induced by source paper "graph theoretic framework for unified analysis of observability and data injection attacks in the smart grid"):
  with members:
    - "game theory for secure critical interdependent gas power water infrastructure"
    - "prospect theory for enhanced smart grid resilience using distributed energy storage"
    - "on bounded rationality in cyber physical systems security game theoretic analysis with application to smart grid protection"
    - "data injection attacks on smart grids with multiple adversaries a game theoretic perspective"
    - "algorithms for implicit hitting set problems"

Connected through hyperedge HE-2 (induced by source paper "actuator security indices based on perfect undetectability computation robustness and sensor placement"):
  with members:
    - "state of the art of cyber physical systems security an automatic control perspective"
    - "a security index for actuators based on perfect undetectability properties and approximation"
    - "controllability metrics limitations and algorithms for complex networks"
    - "learning with submodular functions a convex optimization perspective"

Connected through hyperedge HE-3 (induced by source paper "a security index for actuators based on perfect undetectability properties and approximation"):
  with members:
    - "from control system security indices to attack identifiability"
    - "controllability metrics limitations and algorithms for complex networks"

Connected through hyperedge HE-4 (induced by source paper "graph based cyber security analysis of state estimation in smart power grid"):
  with members:
    - "using covert topological information for defense against malicious attacks on dc state estimation"

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)