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: "compute and forward protocol design based on improved sphere decoding"
  Abstract: We consider the problem of finding the optimal coefficient vector that maximizes the computation rate at a relay in the computer-and-forward scheme. Based on the idea of sphere decoding, we propose a low-complexity method that gives the maximum rate. First, we derive an efficient algorithm to compute the Cholesky factorization by using the structure of the matrix, to transfer the problem to a shortest vector problem (SVP). This algorithm gives the closed-form expression of the Cholesky factor $\R$ with only $\bigO(n^2)$ flops. Based on this $\R$, we propose some conditions that can be checked by $\bigO(n)$ flops, under which the optimal coefficient vector can be obtained immediately without using any search algorithm. Second, by taking into account some resultant useful properties of the optimal coefficient vector, we modify the Schnorr-Euchner search algorithm to solve the SVP. Although the general SVP is suspected to be NP-hard, by studying the properties of $\R$, we show that the average cost of our new algorithm is estimated by $\bigO(n^{2.5})$ for i.i.d. Gaussian channel entries. Numerical simulations show that our proposed branch-and-bound method is much more efficient than the existing one that gives the optimal solution. Besides, compared with the suboptimal methods, our method offers the best performance at a cost lower than that of the LLL method and similar to that of the quadratic programming relaxation method.

Connected through hyperedge HE-1 (induced by source paper "polynomially solvable instances of the shortest and closest vector problems with applications to compute and forward"):
  with members:
    - "low complexity coefficient selection algorithms for compute and forward"
    - "efficient integer coefficient search for compute and forward"
    - "a linearithmic time algorithm for a shortest vector problem in compute and forward design"
    - "a low complexity message recovery method for compute and forward relaying"
    - "asymmetric compute and forward with csit"
    - "an efficient algorithm for optimally solving a shortest vector problem in compute and forward protocol design"
    - "simplified compute and forward and its performance analysis"
    - "integer forcing mimo linear receivers based on lattice reduction"

Connected through hyperedge HE-2 (induced by source paper "a linearithmic time algorithm for a shortest vector problem in compute and forward design"):
  with members:
    - "polynomially solvable instances of the shortest and closest vector problems with applications to compute and forward"
    - "compute and forward finding the best equation"
    - "compute and forward harnessing interference through structured codes"

Connected through hyperedge HE-3 (induced by source paper "a low complexity message recovery method for compute and forward relaying"):
  with members:
    - "compute and forward finding the best equation"
    - "compute and forward on a multiaccess relay channel coding and symmetric rate optimization"
    - "compute and forward harnessing interference through structured codes"

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)