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: "cashtag piggybacking uncovering spam and bot activity in stock microblogs on twitter"
  Abstract: Microblogs are increasingly exploited for predicting prices and traded volumes of stocks in financial markets. However, it has been demonstrated that much of the content shared in microblogging platforms is created and publicized by bots and spammers. Yet, the presence (or lack thereof) and the impact of fake stock microblogs has never systematically been investigated before. Here, we study 9M tweets related to stocks of the 5 main financial markets in the US. By comparing tweets with financial data from Google Finance, we highlight important characteristics of Twitter stock microblogs. More importantly, we uncover a malicious practice - referred to as cashtag piggybacking - perpetrated by coordinated groups of bots and likely aimed at promoting low-value stocks by exploiting the popularity of high-value ones. Among the findings of our study is that as much as 71% of the authors of suspicious financial tweets are classified as bots by a state-of-the-art spambot detection algorithm. Furthermore, 37% of them were suspended by Twitter a few months after our investigation. Our results call for the adoption of spam and bot detection techniques in all studies and applications that exploit user-generated content for predicting the stock market.

Connected through hyperedge HE-1 (induced by source paper "the art of social bots a review and a refined taxonomy"):
  with members:
    - "sybilfuse combining local attributes with global structure to perform robust sybil detection"
    - "lobo evaluation of generalization deficiencies in twitter bot classifiers"
    - "false information on web and social media a survey"
    - "measuring social spam and the effect of bots on information diffusion in social media"
    - "detecting influence campaigns in social networks using the ising model"
    - "botnet campaign detection on twitter"
    - "an unsupervised approach to detect spam campaigns that use botnets on twitter"
    - "sybilblind detecting fake users in online social networks without manual labels"

Connected through hyperedge HE-2 (induced by source paper "scalable and generalizable social bot detection through data selection"):
  with members:
    - "real time event detection on social data streams"
    - "rtbust exploiting temporal patterns for botnet detection on twitter"
    - "its all in a name detecting and labeling bots by their name"
    - "arming the public with artificial intelligence to counter social bots"
    - "bot electioneering volume visualizing social bot activity during elections"
    - "consistent individualized feature attribution for tree ensembles"
    - "lobo evaluation of generalization deficiencies in twitter bot classifiers"
    - "deep neural networks for bot detection"

Connected through hyperedge HE-3 (induced by source paper "the role of bot squads in the political propaganda on twitter"):
  with members:
    - "better safe than sorry an adversarial approach to improve social bot detection"
    - "influence of fake news in twitter during the 2016 us presidential election"
    - "polarization of the vaccination debate on facebook"
    - "the spread of low credibility content by social bots"
    - "social fingerprinting detection of spambot groups through dna inspired behavioral modeling"
    - "spectrum based deep neural networks for fraud detection"
    - "disinformation and social bot operations in the run up to the 2017 french presidential election"
    - "holoscope topology and spike aware fraud detection"

Connected through hyperedge HE-4 (induced by source paper "the limited reach of fake news on twitter during 2019 european elections"):
  with members:
    - "influence of fake news in twitter during the 2016 us presidential election"
    - "polarization and fake news early warning of potential misinformation targets"
    - "misinformation spreading on facebook"
    - "the anatomy of brexit debate on facebook"
    - "science vs conspiracy collective narratives in the age of misinformation"

Connected through hyperedge HE-5 (induced by source paper "identifying and analyzing cryptocurrency manipulations in social media"):
  with members:
    - "online human bot interactions detection estimation and characterization"
    - "the darpa twitter bot challenge"
    - "political bots and the manipulation of public opinion in venezuela"
    - "social signals and algorithmic trading of bitcoin"

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.SI(Social and Information Networks)