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: "an efficient quasi physical algorithm for packing equal circles in a circular container"
  Abstract: This paper addresses the equal circle packing problem, and proposes an efficient quasi-physical algorithm(EQPA). EQPA is based on an improved BFGS algorithm and a new basin hopping strategy. Starting form a random initial pattern, we use the modified BFGS algorithm to reach a local minimum pattern. The modified BFGS algorithm fully utilizes the neighborhood information and considerably speeds up the running time of the gradient descent process, and the efficiency is more apparent for larger scale instances. The new basin-hopping strategy is to shrink the container size when yielding a local minimum pattern. Experimental results indicate that the new basin-hopping strategy is very efficient, especially for a type of pattern with comparatively dense packing in the center and sparse packing around the bounding. We test EQPA on the instances of $n = 1,2,\cdots,320$, and obtain 66 new patterns which have smaller container sizes than the current best-known results reported in literature.

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.CG(Computational Geometry)