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: "multi core processors an overview"
  Abstract: Microprocessors have revolutionized the world we live in and continuous efforts are being made to manufacture not only faster chips but also smarter ones. A number of techniques such as data level parallelism, instruction level parallelism and hyper threading (Intel's HT) already exists which have dramatically improved the performance of microprocessor cores. This paper briefs on evolution of multi-core processors followed by introducing the technology and its advantages in today's world. The paper concludes by detailing on the challenges currently faced by multi-core processors and how the industry is trying to address these issues.

Connected through hyperedge HE-1 (induced by source paper "scaling up reasoning and advanced analytics on bigdata"):
  with members:
    - "vicious circle principle and logic programs with aggregates"
    - "clingo asp control preliminary report"
    - "efficient computation of the well founded semantics over big data"
    - "scaling datalog for machine learning on big data"
    - "relational transducers for declarative networking"
    - "xsb extending prolog with tabled logic programming"
    - "the dlv system for knowledge representation and reasoning"
    - "well founded and stable semantics of logic programs with aggregates"

Connected through hyperedge HE-2 (induced by source paper "adabatch efficient gradient aggregation rules for sequential and parallel stochastic gradient methods"):
  with members:
    - "passcode parallel asynchronous stochastic dual co ordinate descent"
    - "saga a fast incremental gradient method with support for non strongly convex composite objectives"
    - "optimal distributed online prediction using mini batches"

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)