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: "twitter reciprocal reply networks exhibit assortativity with respect to happiness"
  Abstract: The advent of social media has provided an extraordinary, if imperfect, 'big data' window into the form and evolution of social networks. Based on nearly 40 million message pairs posted to Twitter between September 2008 and February 2009, we construct and examine the revealed social network structure and dynamics over the time scales of days, weeks, and months. At the level of user behavior, we employ our recently developed hedonometric analysis methods to investigate patterns of sentiment expression. We find users' average happiness scores to be positively and significantly correlated with those of users one, two, and three links away. We strengthen our analysis by proposing and using a null model to test the effect of network topology on the assortativity of happiness. We also find evidence that more well connected users write happier status updates, with a transition occurring around Dunbar's number. More generally, our work provides evidence of a social sub-network structure within Twitter and raises several methodological points of interest with regard to social network reconstructions.

Connected through hyperedge HE-1 (induced by source paper "networks of power analyzing world leaders interactions on social media"):
  with members:
    - "dyngraph2vec capturing network dynamics using dynamic graph representation learning"
    - "generalized louvain method for community detection in large networks"

Connected through hyperedge HE-2 (induced by source paper "an agent based model for emotion contagion and competition in online social media"):
  with members:
    - "limited individual attention and online virality of low quality information"
    - "measuring emotional contagion in social media"
    - "anger is more influential than joy sentiment correlation in weibo"
    - "agent based model for rural urban migration a dynamic consideration"
    - "the role of social networks in information diffusion"
    - "negative emotions boost user activity at bbc forum"
    - "happiness is assortative in online social networks"
    - "weak ties subtle role of information diffusion in online social networks"

Connected through hyperedge HE-3 (induced by source paper "integrating sentiment and social structure to determine preference alignments the irish marriage referendum"):
  with members:
    - "in the mood the dynamics of collective sentiments on twitter"
    - "sentiment cascades in the 15m movement"
    - "is the sample good enough comparing data from twitter s streaming api with twitter s firehose"
    - "i wanted to predict elections with twitter and all i got was this lousy paper a balanced survey on election prediction using twitter data"
    - "twitter mood predicts the stock market"
    - "seeing stars exploiting class relationships for sentiment categorization with respect to rating scales"
    - "thumbs up or thumbs down semantic orientation applied to unsupervised classification of reviews"

Connected through hyperedge HE-4 (induced by source paper "the minor fall the major lift inferring emotional valence of musical chords through lyrics"):
  with members:
    - "comparing and combining sentiment analysis methods"
    - "measuring the happiness of large scale written expression songs blogs and presidents"

Connected through hyperedge HE-5 (induced by source paper "emoticon based ambivalent expression a hidden indicator for unusual behaviors in weibo"):
  with members:
    - "anger is more influential than joy sentiment correlation in weibo"
    - "happiness is assortative in online social networks"

Connected through hyperedge HE-6 (induced by source paper "empirical big data research a systematic literature mapping"):
  with members:
    - "performance evaluation of a natural language processing approach applied in white collar crime investigation"
    - "performance benefits of datampi a case study with bigdatabench"
    - "multilevel hierarchical kernel spectral clustering for real life large scale complex networks"
    - "graphical evolutionary game for information diffusion over social networks"
    - "the family of mapreduce and large scale data processing systems"
    - "optimizing i o for big array analytics"
    - "pf ola a high performance framework for parallel on line aggregation"
    - "can the elephants handle the nosql onslaught"

Connected through hyperedge HE-7 (induced by source paper "aggregate characterization of user behavior in twitter and analysis of the retweet graph"):
  with members:
    - "crowdsourcing attention and productivity"
    - "correlated dynamics in human printing behavior"

Connected through hyperedge HE-8 (induced by source paper "anger is more influential than joy sentiment correlation in weibo"):
  with members:
    - "negative emotions boost user activity at bbc forum"
    - "happiness is assortative in online social networks"
    - "twitter mood predicts the stock market"
    - "measuring the happiness of large scale written expression songs blogs and presidents"
    - "thumbs up sentiment classification using machine learning techniques"

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)