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: "the pbd closure of constant composition codes"
  Abstract: We show an interesting pairwise balanced design (PBD)-closure result for the set of lengths of constant-composition codes whose distance and size meet certain conditions. A consequence of this PBD-closure result is that the size of optimal constant-composition codes can be determined for infinite families of parameter sets from just a single example of an optimal code. As an application, the sizes of several infinite families of optimal constant-composition codes are derived. In particular, the problem of determining the size of optimal constant-composition codes having distance four and weight three is solved for all lengths sufficiently large. This problem was previously unresolved for odd lengths, except for lengths seven and eleven.

Connected through hyperedge HE-1 (induced by source paper "importance of symbol equity in coded modulation for power line communications"):
  with members:
    - "coded modulation for power line communications"
    - "estimates on the size of symbol weight codes"
    - "linear size optimal q ary constant weight codes and constant composition codes"

Connected through hyperedge HE-2 (induced by source paper "quaternary constant composition codes with weight four and distances five or six"):
  with members:
    - "linear size optimal q ary constant weight codes and constant composition codes"
    - "a construction for constant composition codes"
    - "group divisible codes and their application in the construction of optimal constant composition codes of weight three"
    - "improved lower bounds for constant gc content dna codes"
    - "channel coding the road to channel capacity"

Connected through hyperedge HE-3 (induced by source paper "linear size optimal q ary constant weight codes and constant composition codes"):
  with members:
    - "group divisible codes and their application in the construction of optimal constant composition codes of weight three"
    - "improved lower bounds for constant gc content dna codes"
    - "the sizes of optimal q ary codes of weight three and distance four a complete solution"
    - "constructions for q ary constant weight codes"
    - "channel coding the road to channel capacity"

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.IT(Information Theory)