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: "research productivity are higher academic ranks more productive than lower ones"
  Abstract: This work analyses the links between individual research performance and academic rank. A typical bibliometric methodology is used to study the performance of all Italian university researchers active in the hard sciences, for the period 2004---2008. The objective is to characterize the performance of the ranks of full (FPs), associate and assistant professors (APs), along various dimensions, in order to verify the existence of performance differences among the ranks in general and for single disciplines.

Connected through hyperedge HE-1 (induced by source paper "comparison of research productivity of italian and norwegian professors and universities"):
  with members:
    - "predicting publication long term impact through a combination of early citations and journal impact factor"
    - "the impact of unproductive and top researchers on overall university research performance"
    - "the elephant in the room the problem of quantifying productivity in evaluative scientometrics"
    - "the ratio of top scientists to the academic staff as an indicator of the competitive strength of universities"
    - "not dead just resting the practical value of per publication citation indicators"
    - "efficiency of research performance and the glass researcher"
    - "ranking research institutions by the number of highly cited articles per scientist"
    - "predicting the long term citation impact of recent publications"

Connected through hyperedge HE-2 (induced by source paper "the impact of unproductive and top researchers on overall university research performance"):
  with members:
    - "revisiting size effects in higher education research productivity"
    - "the dispersion of research performance within and between universities as a potential indicator of the competitive intensity in higher education systems"
    - "a heuristic approach to author name disambiguation in bibliometrics databases for large scale research assessments"
    - "national scale research performance assessment at the individual level"
    - "the dangers of performance based research funding in non competitive higher education systems"

Connected through hyperedge HE-3 (induced by source paper "the effects of gender age and academic rank on research diversification"):
  with members:
    - "specialization versus diversification in research activities the extent intensity and relatedness of field diversification by individual scientists"
    - "the combined effects of age and seniority on research performance of full professors"
    - "a heuristic approach to author name disambiguation in bibliometrics databases for large scale research assessments"
    - "gender differences in research productivity a bibliometric analysis of the italian academic system"

Connected through hyperedge HE-4 (induced by source paper "on tit for tat franceschini and maisano versus anvur regarding the italian research assessment exercise vqr 2011 2014"):
  with members:
    - "do they agree bibliometric evaluation versus informed peer review in the italian research assessment exercise"
    - "refrain from adopting the combination of citation and journal metrics to grade publications as used in the italian national research assessment exercise vqr 2011 2014"
    - "the vqr italy s second national research assessment methodological failures and ranking distortions"
    - "inefficiency in selecting products for submission to national research assessment exercises"
    - "measuring institutional research productivity for the life sciences the importance of accounting for the order of authors in the byline"
    - "the importance of accounting for the number of co authors and their order when assessing research performance at the individual level in the life sciences"
    - "national peer review research assessment exercises for the hard sciences can be a complete waste of money the italian case"
    - "national research assessment exercises a comparison of peer review and bibliometrics rankings"

Connected through hyperedge HE-5 (induced by source paper "the research production of nations and departments a statistical model for the share of publications"):
  with members:
    - "conceptual difficulties in the use of statistical inference in citation analysis"
    - "from rankings to funnel plots the question of accounting for uncertainty when assessing university research performance"
    - "a multivariate stochastic model to assess research performance"
    - "funnel plots for visualizing uncertainty in the research performance of institutions"
    - "how do you define and measure research productivity"
    - "the leiden ranking 2011 2012 data collection indicators and interpretation"
    - "research collaboration and productivity is there correlation"
    - "the first italian research assessment exercise a bibliometric perspective"

Connected through hyperedge HE-6 (induced by source paper "the relationship among research productivity research collaboration and their determinants"):
  with members:
    - "the combined effects of age and seniority on research performance of full professors"
    - "variation in research collaboration patterns across academic ranks"
    - "how do you define and measure research productivity"
    - "the collaboration behaviors of scientists in italy a field level analysis"
    - "gender differences in research collaboration"
    - "what is the appropriate length of the publication period over which to assess research performance"
    - "a heuristic approach to author name disambiguation in bibliometrics databases for large scale research assessments"
    - "the relationship between scientists research performance and the degree of internationalization of their research"

Connected through hyperedge HE-7 (induced by source paper "a methodology to measure the effectiveness of academic recruitment and turnover"):
  with members:
    - "the impact of unproductive and top researchers on overall university research performance"
    - "the vqr italy s second national research assessment methodological failures and ranking distortions"
    - "funnel plots for visualizing uncertainty in the research performance of institutions"
    - "the determinants of academic career advancement evidence from italy"
    - "how do you define and measure research productivity"
    - "career advancement and scientific performance in universities"
    - "the importance of accounting for the number of co authors and their order when assessing research performance at the individual level in the life sciences"
    - "what is the appropriate length of the publication period over which to assess research performance"

Connected through hyperedge HE-8 (induced by source paper "the combined effects of age and seniority on research performance of full professors"):
  with members:
    - "measuring science irresistible temptations easy shortcuts and dangerous consequences"
    - "variation in research collaboration patterns across academic ranks"
    - "variability of research performance across disciplines within universities in non competitive higher education systems"
    - "career advancement and scientific performance in universities"
    - "individual research performance a proposal for comparing apples to oranges"
    - "what is the appropriate length of the publication period over which to assess research performance"
    - "how important is choice of the scaling factor in standardizing citations"
    - "a heuristic approach to author name disambiguation in bibliometrics databases for large scale research assessments"

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)