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: "self assembly of 4 sided fractals in the two handed tile assembly model"
  Abstract: We consider the self-assembly of fractals in one of the most well-studied models of tile based self-assembling systems known as the Two-handed Tile Assembly Model (2HAM). In particular, we focus our attention on a class of fractals called discrete self-similar fractals (a class of fractals that includes the discrete Sierpinski carpet). We present a 2HAM system that finitely self-assembles the discrete Sierpinski carpet with scale factor 1. Moreover, the 2HAM system that we give lends itself to being generalized and we describe how this system can be modified to obtain a 2HAM system that finitely self-assembles one of any fractal from an infinite set of fractals which we call 4-sided fractals. The 2HAM systems we give in this paper are the first examples of systems that finitely self-assemble discrete self-similar fractals at scale factor 1 in a purely growth model of self-assembly. Finally, we show that there exists a 3-sided fractal (which is not a tree fractal) that cannot be finitely self-assembled by any 2HAM system.

Connected through hyperedge HE-1 (induced by source paper "hierarchical growth is necessary and sometimes sufficient to self assemble discrete self similar fractals"):
  with members:
    - "hierarchical self assembly of fractals with signal passing tiles extended abstract"
    - "hierarchical self assembly of fractals with signal passing tiles"
    - "scaled tree fractals do not strictly self assemble"
    - "strict self assembly of fractals using multiple hands"
    - "parallelism and time in hierarchical self assembly"
    - "approximate self assembly of the sierpinski triangle"
    - "strict self assembly of discrete sierpinski triangles"
    - "self assembly of the discrete sierpinski carpet and related fractals"

Connected through hyperedge HE-2 (induced by source paper "hierarchical self assembly of fractals with signal passing tiles"):
  with members:
    - "hierarchical self assembly of fractals with signal passing tiles extended abstract"
    - "replication of arbitrary hole free shapes via self assembly with signal passing tiles extended abstract"
    - "scaled tree fractals do not strictly self assemble"
    - "strict self assembly of fractals using multiple hands"
    - "signal transmission across tile assemblies 3d static tiles simulate active self assembly by 2d signal passing tiles"
    - "asynchronous signal passing for tile self assembly fuel efficient computation and efficient assembly of shapes"
    - "two hands are better than one up to constant factors"
    - "approximate self assembly of the sierpinski triangle"

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.ET(Emerging Technologies)