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: "science models as value added services for scholarly information systems"
  Abstract: The paper introduces scholarly Information Retrieval (IR) as a further dimension that should be considered in the science modeling debate. The IR use case is seen as a validation model of the adequacy of science models in representing and predicting structure and dynamics in science. Particular conceptualizations of scholarly activity and structures in science are used as value-added search services to improve retrieval quality: a co-word model depicting the cognitive structure of a field (used for query expansion), the Bradford law of information concentration, and a model of co-authorship networks (both used for re-ranking search results). An evaluation of the retrieval quality when science model driven services are used turned out that the models proposed actually provide beneficial effects to retrieval quality. From an IR perspective, the models studied are therefore verified as expressive conceptualizations of central phenomena in science. Thus, it could be shown that the IR perspective can significantly contribute to a better understanding of scholarly structures and activities.

Connected through hyperedge HE-1 (induced by source paper "analysis of search stratagem utilisation"):
  with members:
    - "investigating exploratory search activities based on the stratagem level in digital libraries"
    - "contextualised browsing in a digital library s living lab"
    - "analysis of footnote chasing and citation searching in an academic search engine"
    - "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"
    - "scientometrics and information retrieval weak links revitalized"

Connected through hyperedge HE-2 (induced by source paper "a usefulness based approach for measuring the local and global effect of iir services"):
  with members:
    - "whose a tool for whole session analysis in iir"
    - "a framework for specific term recommendation systems"
    - "improving retrieval results with discipline specific query expansion"
    - "a novel combined term suggestion service for domain specific digital libraries"

Connected through hyperedge HE-3 (induced by source paper "bibliometric enhanced information retrieval 5th international bir workshop"):
  with members:
    - "evaluating co authorship networks in author name disambiguation for common names"
    - "scientometrics and information retrieval weak links revitalized"

Connected through hyperedge HE-4 (induced by source paper "how can heat maps of indexing vocabularies be utilized for information seeking purposes"):
  with members:
    - "establishing an online access panel for interactive information retrieval research"
    - "bibliometric enhanced information retrieval"

Connected through hyperedge HE-5 (induced by source paper "are topic specific search term journal name and author name recommendations relevant for researchers"):
  with members:
    - "a framework for specific term recommendation systems"
    - "bibliometric enhanced information retrieval"
    - "extending term suggestion with author names"
    - "a novel combined term suggestion service for domain specific digital libraries"

Connected through hyperedge HE-6 (induced by source paper "a survey on the importance of visualization and social collaboration in academic digital libraries"):
  with members:
    - "relevance distributions across bradford zones can bradfordizing improve search"
    - "tracing scientist s research trends realtimely"

Connected through hyperedge HE-7 (induced by source paper "knowledge maps and information retrieval kmir"):
  with members:
    - "reducing semantic complexity in distributed digital libraries treatment of term vagueness and document re ranking"

Connected through hyperedge HE-8 (induced by source paper "relevance distributions across bradford zones can bradfordizing improve search"):
  with members:
    - "using lotkaian informetrics for ranking in digital libraries"
    - "applying science models for search"
    - "cross concordances terminology mapping and its effectiveness for information retrieval"
    - "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)