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: "cross concordances terminology mapping and its effectiveness for information retrieval"
  Abstract: The German Federal Ministry for Education and Research funded a major terminology mapping initiative, which found its conclusion in 2007. The task of this terminology mapping initiative was to organize, create and manage 'cross-concordances' between controlled vocabularies (thesauri, classification systems, subject heading lists) centred around the social sciences but quickly extending to other subject areas. 64 crosswalks with more than 500,000 relations were established. In the final phase of the project, a major evaluation effort to test and measure the effectiveness of the vocabulary mappings in an information system environment was conducted. The paper reports on the cross-concordance work and evaluation results.

Connected through hyperedge HE-1 (induced by source paper "contextualised browsing in a digital library s living lab"):
  with members:
    - "data requirements for evaluation of personalization of information retrieval a position paper"
    - "investigating exploratory search activities based on the stratagem level in digital libraries"
    - "a complete year of user retrieval sessions in a social sciences academic search engine"
    - "a usefulness based approach for measuring the local and global effect of iir services"
    - "extending search facilities via bibliometric enhanced stratagems"

Connected through hyperedge HE-2 (induced by source paper "relevance distributions across bradford zones can bradfordizing improve search"):
  with members:
    - "science models as value added services for scholarly information systems"
    - "using lotkaian informetrics for ranking in digital libraries"
    - "applying science models for search"
    - "reducing semantic complexity in distributed digital libraries treatment of term vagueness and document re ranking"

Connected through hyperedge HE-3 (induced by source paper "making sense of open data statistics with information from wikipedia"):
  with members:
    - "extraction of historical events from wikipedia"
    - "web based multi view visualizations for aggregated statistics"
    - "mining meaning from wikipedia"
    - "the google similarity distance"

Connected through hyperedge HE-4 (induced by source paper "thesoz a skos representation of the thesaurus for the social sciences"):
  with members:
    - "a novel combined term suggestion service for domain specific digital libraries"

Connected through hyperedge HE-5 (induced by source paper "building a terminology network for search"):
  with members:
    - "reducing semantic complexity in distributed digital libraries treatment of term vagueness and document re ranking"
    - "treatment of semantic heterogeneity in information retrieval"

Connected through hyperedge HE-6 (induced by source paper "an evaluation of bradfordizing effects"):
  with members:
    - "reducing semantic complexity in distributed digital libraries treatment of term vagueness and document re ranking"

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)