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: "which cities produce excellent papers worldwide more than can be expected a new mapping approach using google maps based on statistical significance testing"
  Abstract: The methods presented in this paper allow for a statistical analysis revealing centers of excellence around the world using programs that are freely available. Based on Web of Science data, field-specific excellence can be identified in cities where highly-cited papers were published significantly. Compared to the mapping approaches published hitherto, our approach is more analytically oriented by allowing the assessment of an observed number of excellent papers for a city (in the sample) against the expected number. Using this test, the approach cannot only identify the top performers in output but the "true jewels." These are cities locating authors who publish significantly more top cited papers than can be expected. As the examples in this paper show for physics, chemistry, and psychology, these cities do not necessarily have a high output of excellent papers.

Connected through hyperedge HE-1 (induced by source paper "recent developments in china u s cooperation in science"):
  with members:
    - "brics countries and scientific excellence a bibliometric analysis of most frequently cited papers"
    - "the european union china and the united states in the top 1 and top 10 layers of most frequently cited publications competition and collaborations"
    - "research excellence milestones of bric and n 11 countries"
    - "science overlay maps a new tool for research policy and library management"

Connected through hyperedge HE-2 (induced by source paper "patents as instruments for exploring innovation dynamics geographic and technological perspectives on photovoltaic cells"):
  with members:
    - "innovation as a nonlinear process the scientometric perspective and the specification of an innovation opportunities explorer"
    - "mapping excellence in the geography of science an approach based on scopus data"
    - "mapping uspto patent data using overlays to google maps"

Connected through hyperedge HE-3 (induced by source paper "interactive overlays of journals and the measurement of interdisciplinarity on the basis of aggregated journal journal citations"):
  with members:
    - "global maps of science based on the new web of science categories"
    - "interactive overlay maps for us patent uspto data based on international patent classifications ipc"
    - "interdisciplinarity at the journal and specialty level the changing knowledge bases of the journal cognitive science"
    - "interactive overlays a new method for generating global journal maps from web of science data"
    - "the structure of the arts humanities citation index a mapping on the basis of aggregated citations among 1 157 journals"
    - "how journal rankings can suppress interdisciplinary research a comparison between innovation studies and business management"
    - "a unified approach to mapping and clustering of bibliometric networks"
    - "indicators of the interdisciplinarity of journals diversity centrality and citations"

Connected through hyperedge HE-4 (induced by source paper "field normalized impact factors a comparison of rescaling versus fractionally counted ifs"):
  with members:
    - "the weakening relationship between the impact factor and papers citations in the digital age"
    - "alternatives to the journal impact factor i3 and the top 10 or top 25 of the most highly cited papers"
    - "impact factor outdated artefact or stepping stone to journal certification"
    - "the leiden ranking 2011 2012 data collection indicators and interpretation"
    - "edited volumes monographs and book chapters in the book citation index bkci and science citation index sci sosci a hci"
    - "how can journal impact factors be normalized across fields of science an assessment in terms of percentile ranks and fractional counts"
    - "fractional counting of citations in research evaluation a cross and interdisciplinary assessment of the tsinghua university in beijing"
    - "testing differences statistically with the leiden ranking"

Connected through hyperedge HE-5 (induced by source paper "alternatives to the journal impact factor i3 and the top 10 or top 25 of the most highly cited papers"):
  with members:
    - "impact factor outdated artefact or stepping stone to journal certification"
    - "simple arithmetic versus intuitive understanding the case of the impact factor"
    - "a rejoinder on energy versus impact indicators"
    - "fractional counting of citations in research evaluation a cross and interdisciplinary assessment of the tsinghua university in beijing"
    - "betweenness centrality as a driver of preferential attachment in the evolution of research collaboration networks"
    - "testing differences statistically with the leiden ranking"
    - "how journal rankings can suppress interdisciplinary research a comparison between innovation studies and business management"
    - "scopus s source normalized impact per paper snip versus a journal impact factor based on fractional counting of citations"

Connected through hyperedge HE-6 (induced by source paper "interactive overlay maps for us patent uspto data based on international patent classifications ipc"):
  with members:
    - "how to create an innovation accelerator"
    - "interactive overlays a new method for generating global journal maps from web of science data"
    - "publish or patent bibliometric evidence for empirical trade offs in national funding strategies"
    - "the structure of the arts humanities citation index a mapping on the basis of aggregated citations among 1 157 journals"
    - "how journal rankings can suppress interdisciplinary research a comparison between innovation studies and business management"
    - "a unified approach to mapping and clustering of bibliometric networks"
    - "indicators of the interdisciplinarity of journals diversity centrality and citations"
    - "a comparison of two techniques for bibliometric mapping multidimensional scaling and vos"

Connected through hyperedge HE-7 (induced by source paper "innovation as a nonlinear process the scientometric perspective and the specification of an innovation opportunities explorer"):
  with members:
    - "the knowledge based economy and the triple helix model"
    - "how to create an innovation accelerator"
    - "mapping excellence in the geography of science an approach based on scopus data"
    - "interactive overlays a new method for generating global journal maps from web of science data"
    - "what can heterogeneity add to the scientometric map steps towards algorithmic historiography"
    - "mapping the geography of science distribution patterns and networks of relations among cities and institutes"
    - "science overlay maps a new tool for research policy and library management"

Connected through hyperedge HE-8 (induced by source paper "bibliometric perspectives on medical innovation using the medical subject headings mesh of pubmed"):
  with members:
    - "how to create an innovation accelerator"
    - "interactive overlays a new method for generating global journal maps from web of science data"
    - "the structure of the arts humanities citation index a mapping on the basis of aggregated citations among 1 157 journals"
    - "a unified approach to mapping and clustering of bibliometric networks"
    - "mapping the geography of science distribution patterns and networks of relations among cities and institutes"
    - "co occurrence matrices and their applications in information science extending aca to the web environment"
    - "science overlay maps a new tool for research policy and library management"

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.DL(Digital Libraries)