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: "face guarding polyhedra"
  Abstract: We study the Art Gallery Problem for face guards in polyhedral environments. The problem can be informally stated as: how many (not necessarily convex) windows should we place on the external walls of a dark building, in order to completely illuminate its interior? #R##N#We consider both closed and open face guards (i.e., faces with or without their boundary), and we study several classes of polyhedra, including orthogonal polyhedra, 4-oriented polyhedra, and 2-reflex orthostacks. #R##N#We give upper and lower bounds on the minimum number of faces required to guard the interior of a given polyhedron in each of these classes, in terms of the total number of its faces, f. In several cases our bounds are tight: f/6 open face guards for orthogonal polyhedra and 2-reflex orthostacks, and f/4 open face guards for 4-oriented polyhedra. Additionally, for closed face guards in 2-reflex orthostacks, we give a lower bound of (f+3)/9 and an upper bound of (f+1)/7. #R##N#Then we show that it is NP-hard to approximate the minimum number of (closed or open) face guards within a factor of Omega(log f), even for polyhedra that are orthogonal and simply connected. We also obtain the same hardness results for polyhedral terrains. #R##N#Along the way we discuss some applications, arguing that face guards are not a reasonable model for guards patrolling on the surface of a polyhedron.

Connected through hyperedge HE-1 (induced by source paper "on the complexity of minimum link path problems"):
  with members:
    - "region based approximation of probability distributions for visibility between imprecise points among obstacles"
    - "minimum link paths revisited"
    - "an algorithm for computing constrained reflection paths in simple polygon"
    - "terrain visibility with multiple viewpoints"

Connected through hyperedge HE-2 (induced by source paper "optimally guarding 2 reflex orthogonal polyhedra by reflex edge guards"):
  with members:
    - "guarding and searching polyhedra"
    - "hidden mobile guards in simple polygons"

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.CG(Computational Geometry)