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: "a principal component analysis of 39 scientific impact measures"
  Abstract: Background: The impact of scientific publications has traditionally been expressed in terms of citation counts. However, scientific activity has moved online over the past decade. To better capture scientific impact in the digital era, a variety of new impact measures has been proposed on the basis of social network analysis and usage log data. Here we investigate how these new measures relate to each other, and how accurately and completely they express scientific impact. Methodology: We performed a principal component analysis of the rankings produced by 39 existing and proposed measures of scholarly impact that were calculated on the basis of both citation and usage log data. Conclusions: Our results indicate that the notion of scientific impact is a multi-dimensional construct that can not be adequately measured by any single indicator, although some measures are more suitable than others. The commonly used citation Impact Factor is not positioned at the core of this construct, but at its periphery, and should thus be used with caution.

Connected through hyperedge HE-1 (induced by source paper "the relationship between usage and citations in an open access mega journal"):
  with members:
    - "the open access advantage considering citation article usage and social media attention"
    - "self selected or mandated open access increases citation impact for higher quality research"
    - "toward alternative metrics of journal impact a comparison of download and citation data"

Connected through hyperedge HE-2 (induced by source paper "author level metrics in the new academic profile platforms the online behaviour of the bibliometrics community"):
  with members:
    - "a novel method for depicting academic disciplines through google scholar citations the case of bibliometrics"
    - "can we use google scholar to identify highly cited documents"
    - "do researchgate scores create ghost academic reputations"
    - "scholars on twitter who and how many are they"
    - "grand challenges in altmetrics heterogeneity data quality and dependencies"
    - "scholarly use of social media and altmetrics a review of the literature"
    - "a review of the characteristics of 108 author level bibliometric indicators"
    - "do altmetrics correlate with citations extensive comparison of altmetric indicators with citations from a multidisciplinary perspective"

Connected through hyperedge HE-3 (induced by source paper "measuring field normalized impact of papers on specific societal groups an altmetrics study based on mendeley data"):
  with members:
    - "policy documents as sources for measuring societal impact how often is climate change research mentioned in policy related documents"
    - "validity of altmetrics data for measuring societal impact a study using data from altmetric and f1000prime"
    - "tweets vs mendeley readers how do these two social media metrics differ"
    - "alternative metrics in scientometrics a meta analysis of research into three altmetrics"
    - "do altmetrics point to the broader impact of research an overview of benefits and disadvantages of altmetrics"
    - "genesis of altmetrics or article level metrics for measuring efficacy of scholarly communications current perspectives"
    - "how well developed are altmetrics a cross disciplinary analysis of the presence of alternative metrics in scientific publications"
    - "the role of twitter in the life cycle of a scientific publication"

Connected through hyperedge HE-4 (induced by source paper "social media attention increases article visits an investigation on article level referral data of peerj"):
  with members:
    - "mendeley readership as a filtering tool to identify highly cited publications"
    - "the open access advantage considering citation article usage and social media attention"
    - "usage history of scientific literature nature metrics and metrics of nature publications"
    - "do altmetrics correlate with citations extensive comparison of altmetric indicators with citations from a multidisciplinary perspective"
    - "do altmetrics point to the broader impact of research an overview of benefits and disadvantages of altmetrics"
    - "tweeting biomedicine an analysis of tweets and citations in the biomedical literature"
    - "exploring scientists working timetable do scientists often work overtime"
    - "altmetrics in the wild using social media to explore scholarly impact"

Connected through hyperedge HE-5 (induced by source paper "an empirical and theoretical critique of the euclidean index"):
  with members:
    - "professional and citizen bibliometrics complementarities and ambivalences in the development and use of indicators"
    - "counting publications and citations is more always better"
    - "the leiden ranking 2011 2012 data collection indicators and interpretation"
    - "the inconsistency of the h index"
    - "assessing scientific research performance and impact with single indices"
    - "citation counting citation ranking and h index of human computer interaction researchers a comparison between scopus and web of science"

Connected through hyperedge HE-6 (induced by source paper "grand challenges in measuring and characterizing scholarly impact"):
  with members:
    - "universality of scholarly impact metrics"
    - "the structure of the arts humanities citation index a mapping on the basis of aggregated citations among 1 157 journals"
    - "cwts crown indicator measures citation impact of a research group s publication oeuvre"
    - "measuring contextual citation impact of scientific journals"

Connected through hyperedge HE-7 (induced by source paper "quantifying perceived impact of scientific publications"):
  with members:
    - "quantifying long term scientific impact"

Connected through hyperedge HE-8 (induced by source paper "a review of the literature on citation impact indicators"):
  with members:
    - "a sensitivity analysis of researchers productivity rankings to the time of citation observation"
    - "the precision of the arithmetic mean geometric mean and percentiles for citation data an experimental simulation modelling approach"
    - "the journal coverage of web of science and scopus a comparative analysis"
    - "measuring academic influence not all citations are equal"
    - "a review of theory and practice in scientometrics"
    - "comprehensive indicator comparisons intelligible to non experts the case of two snip versions"
    - "methods for estimating the size of google scholar"
    - "large scale analysis of the accuracy of the journal classification systems of web of science and scopus"

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)