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: "covering a line segment with variable radius discs"
  Abstract: The paper addresses the problem of locating sensors with a circular field of view so that a given line segment is under full surveillance, which is termed as the Disc Covering Problem on a Line. The cost of each sensor includes a fixed component, and a variable component that is proportional to the field-of-view area. When only one type of sensor or, in general, one type of disc, is available, then a simple polynomial algorithm solves the problem. When there are different types of sensors in terms of fixed and variable costs, the problem becomes NP-hard. A branch-and-bound algorithm as well as an efficient heuristic are developed. The heuristic very often obtains the optimal solution as shown in extensive computational testing.

Connected through hyperedge HE-1 (induced by source paper "worst case optimal covering of rectangles by disks"):
  with members:
    - "split packing algorithms for packing circles with optimal worst case density"
    - "a constant factor approximation for multi covering with disks"
    - "circle packing for origami design is hard"

Connected through hyperedge HE-2 (induced by source paper "approximation algorithms for road coverage using wireless sensor networks for moving objects monitoring"):
  with members:
    - "approximation algorithms for deployment of sensors for line segment coverage in wireless sensor networks"

Connected through hyperedge HE-3 (induced by source paper "minimizing the aggregate movements for interval coverage"):
  with members:
    - "maximizing barrier coverage lifetime with mobile sensors"
    - "algorithms on minimizing the maximum sensor movement for barrier coverage of a linear domain"
    - "optimal point movement for covering circular regions"
    - "decomposing coverings and the planar sensor cover problem"
    - "restricted strip covering and the sensor cover problem"

Connected through hyperedge HE-4 (induced by source paper "maximizing barrier coverage lifetime with mobile sensors"):
  with members:
    - "algorithms on minimizing the maximum sensor movement for barrier coverage of a linear domain"
    - "set it and forget it approximating the set once strip cover problem"
    - "decomposing coverings and the planar sensor cover problem"
    - "restricted strip covering and the sensor cover problem"

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.DM(Discrete Mathematics)