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: "timing model extraction for sequential circuits considering process variations"
  Abstract: As semiconductor devices continue to scale down, process variations become more relevant for circuit design. Facing such variations, statistical static timing analysis is introduced to model variations more accurately so that the pessimism in traditional worst case timing analysis is reduced. Because all delays are modeled using correlated random variables, most statistical timing methods are much slower than corner based timing analysis. To speed up statistical timing analysis, we propose a method to extract timing models for flip-flop and latch based sequential circuits respectively. When such a circuit is used as a module in a hierarchical design, the timing model instead of the original circuit is used for timing analysis. The extracted timing models are much smaller than the original circuits. Experiments show that using extracted timing models accelerates timing verification by orders of magnitude compared to previous approaches using flat netlists directly. Accuracy is maintained, however, with the mean and standard deviation of the clock period both showing usually less than 1% error compared to Monte Carlo simulation on a number of benchmark circuits.

Connected through hyperedge HE-1 (induced by source paper "on timing model extraction and hierarchical statistical timing analysis"):
  with members:
    - "on hierarchical statistical static timing analysis"

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.AR(Hardware Architecture)