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: "towards effective research recommender systems for repositories"
  Abstract: In this paper, we argue why and how the integration of recommender systems for research can enhance the functionality and user experience in repositories. We present the latest technical innovations in the CORE Recommender, which provides research article recommendations across the global network of repositories and journals. The CORE Recommender has been recently redeveloped and released into production in the CORE system and has also been deployed in several third-party repositories. We explain the design choices of this unique system and the evaluation processes we have in place to continue raising the quality of the provided recommendations. By drawing on our experience, we discuss the main challenges in offering a state-of-the-art recommender solution for repositories. We highlight two of the key limitations of the current repository infrastructure with respect to developing research recommender systems: 1) the lack of a standardised protocol and capabilities for exposing anonymised user-interaction logs, which represent critically important input data for recommender systems based on collaborative filtering and 2) the lack of a voluntary global sign-on capability in repositories, which would enable the creation of personalised recommendation and notification solutions based on past user interactions.

Connected through hyperedge HE-1 (induced by source paper "online evaluations for everyone mr dlib s living lab for scholarly recommendations"):
  with members:
    - "rard ii the 2nd related article recommendation dataset"
    - "the architecture of mr dlib s scientific recommender system api"
    - "rard ii the 94 million related article recommendation dataset"
    - "contextualised browsing in a digital library s living lab"
    - "graph embedding for citation recommendation"
    - "mr dlib recommendations as a service raas for academia"
    - "the conference paper assignment problem using order weighted averages to assign indivisible goods"
    - "evaluation as a service overview and outlook"

Connected through hyperedge HE-2 (induced by source paper "rard ii the 94 million related article recommendation dataset"):
  with members:
    - "online evaluations for everyone mr dlib s living lab for scholarly recommendations"
    - "mr dlib recommendations as a service raas for academia"
    - "towards effective research paper recommender systems and user modeling based on mind maps"
    - "openml networked science in machine learning"
    - "collaborative filtering by personality diagnosis a hybrid memory and model based approach"
    - "algorithm selection for combinatorial search problems a survey"

Connected through hyperedge HE-3 (induced by source paper "the architecture of mr dlib s scientific recommender system api"):
  with members:
    - "online evaluations for everyone mr dlib s living lab for scholarly recommendations"
    - "rard ii the 94 million related article recommendation dataset"

Connected through hyperedge HE-4 (induced by source paper "mr dlib recommendations as a service raas for academia"):
  with members:
    - "exploring choice overload in related article recommendations in digital libraries"

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)