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: "directed information on abstract spaces properties and variational equalities"
  Abstract: Directed information or its variants are utilized extensively in the characterization of the capacity of channels with memory and feedback, nonanticipative lossy data compression, and their generalizations to networks. In this paper, we derive several functional and topological properties of directed information for general abstract alphabets (complete separable metric spaces) using the topology of weak convergence of probability measures. These include convexity of the set of consistent distributions, which uniquely define causally conditioned distributions, convexity and concavity of directed information with respect to the sets of consistent distributions, weak compactness of these sets of distributions, their joint distributions and their marginals. Furthermore, we show lower semicontinuity of directed information, and under certain conditions we also establish continuity of directed information. Finally, we derive variational equalities for directed information, including sequential versions. These may be viewed as the analogue of the variational equalities of mutual information (utilized in Blahut-Arimoto algorithm). #R##N#In summary, we extend the basic functional and topological properties of mutual information to directed information. These properties are discussed in the context of extremum problems of directed information.

Connected through hyperedge HE-1 (induced by source paper "a converse bound characterization on zero delay indirect rdf for vector gauss markov sources"):
  with members:
    - "zero delay rate distortion via filtering for vector valued gaussian sources"
    - "optimal estimation via nonanticipative rate distortion function and applications to time varying gauss markov processes"
    - "internet of things iot a vision architectural elements and future directions"
    - "improved upper bounds to the causal quadratic rate distortion function for gaussian stationary sources"

Connected through hyperedge HE-2 (induced by source paper "on zero delay rdf for vector valued gauss markov sources with additional noise"):
  with members:
    - "zero delay rate distortion via filtering for vector valued gaussian sources"
    - "optimal estimation via nonanticipative rate distortion function and applications to time varying gauss markov processes"
    - "indirect rate distortion function of a binary i i d source"
    - "internet of things iot a vision architectural elements and future directions"
    - "improved upper bounds to the causal quadratic rate distortion function for gaussian stationary sources"

Connected through hyperedge HE-3 (induced by source paper "zero delay rate distortion via filtering for vector valued gaussian sources"):
  with members:
    - "an upper bound to zero delay rate distortion via kalman filtering for vector gaussian sources"
    - "filtering with fidelity for time varying gauss markov processes"
    - "a characterization of the minimal average data rate that guarantees a given closed loop performance level"
    - "nonanticipative rate distortion function and relations to filtering theory"
    - "improved upper bounds to the causal quadratic rate distortion function for gaussian stationary sources"
    - "achieving the gaussian rate distortion function by prediction"

Connected through hyperedge HE-4 (induced by source paper "single letter expression of capacity for a class of channels with memory"):
  with members:
    - "information structures of capacity achieving distributions for feedback channels with memory and transmission cost stochastic optimal control variational equalities part i"
    - "capacity of binary state symmetric channel with and without feedback and transmission cost"
    - "information structures for feedback capacity of channels with memory and transmission cost stochastic optimal control variational equalities part i"
    - "capacity of a post channel with and without feedback"
    - "capacity and coding for the ising channel with feedback"

Connected through hyperedge HE-5 (induced by source paper "an upper bound to zero delay rate distortion via kalman filtering for vector gaussian sources"):
  with members:
    - "filtering with fidelity for time varying gauss markov processes"
    - "improved upper bounds to the causal quadratic rate distortion function for gaussian stationary sources"

Connected through hyperedge HE-6 (induced by source paper "zero delay rate distortion via filtering for unstable vector gaussian sources"):
  with members:
    - "improved upper bounds to the causal quadratic rate distortion function for gaussian stationary sources"

Connected through hyperedge HE-7 (induced by source paper "sequential necessary and sufficient conditions for capacity achieving distributions of channels with memory and feedback"):
  with members:
    - "capacity achieving distributions information lossless randomized strategies for feedback channels with memory the lqg theory of directed information part ii"
    - "a single letter upper bound on the feedback capacity of unifilar finite state channels"
    - "information structures of capacity achieving distributions for feedback channels with memory and transmission cost stochastic optimal control variational equalities part i"
    - "capacity of binary state symmetric channel with and without feedback and transmission cost"
    - "information structures for feedback capacity of channels with memory and transmission cost stochastic optimal control variational equalities part i"
    - "capacity of a post channel with and without feedback"
    - "directed information on abstract spaces properties and extremum problems"
    - "capacity and coding for the ising channel with feedback"

Connected through hyperedge HE-8 (induced by source paper "filtering with fidelity for time varying gauss markov processes"):
  with members:
    - "optimal nonanticipative estimation schemes for time varying gauss markov processes"
    - "nonanticipative rate distortion function and relations to filtering theory"
    - "improved upper bounds to the causal quadratic rate distortion function for gaussian stationary sources"

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.IT(Information Theory)