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: "no more chasing waterfalls a measurement study of the header bidding ad ecosystem"
  Abstract: In the last few years, Header Bidding (HB) has gained popularity among web publishers and is challenging the status quo in the ad ecosystem. Contrary to the traditional waterfall standard, HB aims to give back control of the ad inventory to publishers, increase transparency, fairness and competition among advertisers, thus, resulting in higher ad-slot prices. Although promising, little is known about this new ad-tech protocol: How does it work internally and what are the different implementations of HB? What is the performance overhead, and how does it affect the user experience? Does it, indeed, provide higher revenues to publishers than the waterfall model? Who are the dominating entities in this new protocol? #R##N#To respond to all these questions and shed light on this new, buzzing ad-technology, we design and implement HBDetector: a holistic HB detection mechanism that can capture HB auctions independently of the implementation followed in a website. By running HBDetector across the top 35,000 Alexa websites, we collect and analyze a dataset of 800k auctions. Our results show that: (i) 14.28% of the top Alexa websites utilize HB. (ii) Publishers tend to collaborate mostly with a relatively low number of demand partners, which are already big players in waterfall standard, (iii) HB latency can be significantly higher than waterfall, with up to 3x latency in the median cases.

Connected through hyperedge HE-1 (induced by source paper "stop tracking me bro differential tracking of user demographics on hyper partisan websites"):
  with members:
    - "characterising third party cookie usage in the eu after gdpr"
    - "tweeting mps digital engagement between citizens and members of parliament in the uk"
    - "cookie synchronization everything you always wanted to know but were afraid to ask"
    - "tracing information flows between ad exchanges using retargeted ads"
    - "talon an automated framework for cross device tracking detection"
    - "illuminating an ecosystem of partisan websites"
    - "whotracks me shedding light on the opaque world of online tracking"
    - "targeted advertising based on browsing history"

Connected through hyperedge HE-2 (induced by source paper "keeping out the masses understanding the popularity and implications of internet paywalls"):
  with members:
    - "cookie synchronization everything you always wanted to know but were afraid to ask"
    - "speedreader reader mode made fast and private"
    - "who filters the filters understanding the growth usefulness and efficiency of crowdsourced ad blocking"
    - "truth in web mining measuring the profitability and cost of cryptominers as a web monetization model"
    - "tracking the trackers towards understanding the mobile advertising and tracking ecosystem"

Connected through hyperedge HE-3 (induced by source paper "another brick in the paywall the popularity and privacy implications of paywalls"):
  with members:
    - "cookie synchronization everything you always wanted to know but were afraid to ask"
    - "speedreader reader mode made fast and private"
    - "who filters the filters understanding the growth usefulness and efficiency of crowdsourced ad blocking"
    - "truth in web mining measuring the profitability and cost of cryptominers as a web monetization model"
    - "tracking the trackers towards understanding the mobile advertising and tracking ecosystem"

Connected through hyperedge HE-4 (induced by source paper "inferring tracker advertiser relationships in the online advertising ecosystem using header bidding"):
  with members:
    - "tracking the pixels detecting web trackers via analyzing invisible pixels"
    - "cookie synchronization everything you always wanted to know but were afraid to ask"
    - "tracing information flows between ad exchanges using retargeted ads"
    - "tracking the trackers towards understanding the mobile advertising and tracking ecosystem"
    - "your browsing behavior for a big mac economics of personal information online"

Connected through hyperedge HE-5 (induced by source paper "talon an automated framework for cross device tracking detection"):
  with members:
    - "cookie synchronization everything you always wanted to know but were afraid to ask"
    - "tracing information flows between ad exchanges using retargeted ads"
    - "myadchoices bringing transparency and control to online advertising"
    - "cross device tracking matching devices and cookies"
    - "i always feel like somebody s watching me measuring online behavioural advertising"

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.CY(Computers and Society)