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: "threshold improvement of low density lattice codes via spatial coupling"
  Abstract: Spatially-coupled low-density lattice codes (LDLC) are constructed using protographs. Using Monte Carlo density evolution using single-Gaussian messages, we observe that the threshold of the spatially-coupled LDLC is within 0.22 dB of capacity of the unconstrained power channel. This is in contrast with a 0.5 dB noise threshold for the conventional LDLC lattice construction.

Connected through hyperedge HE-1 (induced by source paper "repeat accumulate signal codes"):
  with members:
    - "on the design of multi dimensional irregular repeat accumulate lattice codes"
    - "leech constellations of construction a lattices"
    - "turbo lattices construction and error decoding performance"
    - "design and analysis of nonbinary ldpc codes for arbitrary discrete memoryless channels"

Connected through hyperedge HE-2 (induced by source paper "a simple proof of maxwell saturation for coupled scalar recursions"):
  with members:
    - "threshold saturation for spatially coupled ldpc and ldgm codes on bms channels"
    - "approaching the rate distortion limit with spatial coupling belief propagation and decimation"
    - "threshold saturation in spatially coupled constraint satisfaction problems"
    - "nonbinary spatially coupled ldpc codes on the binary erasure channel"
    - "a proof of threshold saturation for spatially coupled ldpc codes on bms channels"
    - "thresholds of spatially coupled systems via lyapunov s method"
    - "spatial coupling as a proof technique"
    - "a simple proof of threshold saturation for coupled scalar recursions"

Connected through hyperedge HE-3 (induced by source paper "spatially coupled ensembles universally achieve capacity under belief propagation"):
  with members:
    - "a simple proof of threshold saturation for coupled scalar recursions"
    - "universal bounds on the scaling behavior of polar codes"
    - "windowed decoding of protograph based ldpc convolutional codes over erasure channels"
    - "chains of mean field models"
    - "a phenomenological study on threshold improvement via spatial coupling"
    - "wave like solutions of general one dimensional spatially coupled systems"
    - "extended extremes of information combining"
    - "threshold saturation on channels with memory via spatial coupling"

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)