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: "optimal placement delivery arrays with minimum number of rows"
  Abstract: Coded caching scheme, which is an effective technique to reduce the load during peak traffic times, has recently become quite popular among the coding community. A placement delivery array (PDA in short) can be used to design a coded caching scheme. The number of rows of a PDA corresponds to the subpacketization level in the coded caching scheme. Thus, it is meaningful to construct the optimal PDAs with minimum number of rows. However, no one has yet proved that one of the previously known PDAs (or optimal PDAs) has minimum number of rows. We mainly focus on such optimal PDAs in this paper. We first prove that one class of the optimal PDAs by Maddah-Ali and Niesen has minimum number of rows. Next other two classes of optimal PDAs with minimum number of rows are obtained and proved from a new characterization of a PDA by means of a set of $3$ dimensional vectors and a new derived lower bound.

Connected through hyperedge HE-1 (induced by source paper "subexponential and linear subpacketization coded caching via line graphs and projective geometry"):
  with members:
    - "some new constructions of coded caching schemes with reduced subpacketization"
    - "a multi antenna coded caching scheme with linear subpacketization"
    - "decentralized coded caching without file splitting"
    - "subpacketization rate trade off in multi antenna coded caching"
    - "coded caching based on combinatorial designs"
    - "a unified framework for constructing centralized coded caching schemes"
    - "low subpacketization coded caching via projective geometry for broadcast and d2d networks"
    - "coded caching via projective geometry a new low subpacketization scheme"

Connected through hyperedge HE-2 (induced by source paper "a unified framework for constructing centralized coded caching schemes"):
  with members:
    - "coded caching based on combinatorial designs"
    - "the exact rate memory tradeoff for caching with uncoded prefetching"
    - "coded caching via line graphs of bipartite graphs"
    - "placement delivery array design through strong edge coloring of bipartite graphs"
    - "adding transmitters dramatically boosts coded caching gains for finite file sizes"
    - "on the placement delivery array design for centralized coded caching scheme"
    - "coded caching with linear subpacketization is possible using ruzsa szem eredi graphs"
    - "coded caching schemes with reduced subpacketization from linear block codes"

Connected through hyperedge HE-3 (induced by source paper "subpacketization in coded caching with demand privacy"):
  with members:
    - "on coded caching with private demands"
    - "demand private coded caching"
    - "the exact rate memory tradeoff for caching with uncoded prefetching"
    - "placement delivery array design through strong edge coloring of bipartite graphs"
    - "on the placement delivery array design for centralized coded caching scheme"
    - "coded caching schemes with reduced subpacketization from linear block codes"
    - "private broadcasting an index coding approach"
    - "centralized coded caching schemes a hypergraph theoretical approach"

Connected through hyperedge HE-4 (induced by source paper "improved constructions of coded caching schemes for combination networks"):
  with members:
    - "caching in combination networks a novel delivery by leveraging the network topology"
    - "placement delivery array design for combination networks with edge caching"
    - "placement delivery array design through strong edge coloring of bipartite graphs"
    - "on combination networks with cache aided relays and users"
    - "a novel asymmetric coded placement in combination networks with end user caches"
    - "on the placement delivery array design for centralized coded caching scheme"
    - "caching in combination networks novel multicast message generation and delivery by leveraging the network topology"
    - "combination networks with or without secrecy constraints the impact of caching relays"

Connected through hyperedge HE-5 (induced by source paper "coded caching via projective geometry a new low subpacketization scheme"):
  with members:
    - "coded caching via line graphs of bipartite graphs"
    - "placement delivery array design through strong edge coloring of bipartite graphs"
    - "on the placement delivery array design for centralized coded caching scheme"
    - "coded caching schemes with reduced subpacketization from linear block codes"
    - "on the optimality of uncoded cache placement"
    - "fundamental limits of caching"

Connected through hyperedge HE-6 (induced by source paper "linear coded caching scheme for centralized networks"):
  with members:
    - "the exact rate memory tradeoff for caching with uncoded prefetching"
    - "coded caching via line graphs of bipartite graphs"
    - "placement delivery array design through strong edge coloring of bipartite graphs"
    - "on the placement delivery array design for centralized coded caching scheme"
    - "coded caching with linear subpacketization is possible using ruzsa szem eredi graphs"
    - "coded caching schemes with reduced subpacketization from linear block codes"
    - "uncoded placement optimization for coded delivery"
    - "a novel recursive construction for coded caching schemes"

Connected through hyperedge HE-7 (induced by source paper "from centralized to decentralized coded caching"):
  with members:
    - "placement delivery array design through strong edge coloring of bipartite graphs"
    - "on the placement delivery array design for centralized coded caching scheme"
    - "coded caching with linear subpacketization is possible using ruzsa szem eredi graphs"
    - "coded caching schemes with reduced subpacketization from linear block codes"
    - "rate memory trade off for the two user broadcast caching network with correlated sources"
    - "structural properties of uncoded placement optimization for coded delivery"
    - "wireless caching technical misconceptions and business barriers"
    - "centralized coded caching schemes a hypergraph theoretical approach"

Connected through hyperedge HE-8 (induced by source paper "some new bounds of placement delivery arrays"):
  with members:
    - "placement delivery array design through strong edge coloring of bipartite graphs"
    - "a new converse bound for coded caching"
    - "fundamental limits of caching improved delivery rate cache capacity trade off"
    - "centralized coded caching schemes a hypergraph theoretical approach"
    - "the optimal placement delivery arrays"
    - "new results for traitor tracing schemes"
    - "a note on the fundamental limits of coded caching"
    - "hierarchical coded caching"

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)