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: "robust sound source localization using a microphone array on a mobile robot"
  Abstract: The hearing sense on a mobile robot is important because it is omnidirectional and it does not require direct line-of-sight with the sound source. Such capabilities can nicely complement vision to help localize a person or an interesting event in the environment. To do so the robot auditory system must be able to work in noisy, unknown and diverse environmental conditions. In this paper, we present a robust sound source localization method in three-dimensional space using an array of 8 microphones. The method is based on time delay of arrival estimation. Results show that a mobile robot can localize in real time different types of sound sources over a range of 3 meters and with a precision of 3/spl deg/.

Connected through hyperedge HE-1 (induced by source paper "semi supervised source localization on multiple manifolds with distributed microphones"):
  with members:
    - "multiple speaker localization based on direct path features and likelihood maximization with spatial sparsity regularization"
    - "towards a generalization of relative transfer functions to more than one source"
    - "semi supervised sound source localization based on manifold regularization"
    - "acoustic space learning for sound source separation and localization on binaural manifolds"

Connected through hyperedge HE-2 (induced by source paper "auditory system for a mobile robot"):
  with members:
    - "enhanced robot audition based on microphone array source separation with post filter"
    - "localization of simultaneous moving sound sources for mobile robot using a frequency domain steered beamformer approach"
    - "microphone array post filter for separation of simultaneous non stationary sources"

Connected through hyperedge HE-3 (induced by source paper "a review of verbal and non verbal human robot interactive communication"):
  with members:
    - "robust localization and tracking of simultaneous moving sound sources using beamforming and particle filtering"
    - "explorations in engagement for humans and robots"
    - "localization of simultaneous moving sound sources for mobile robot using a frequency domain steered beamformer approach"
    - "grounding the lexical semantics of verbs in visual perception using force dynamics and event logic"
    - "the symbol grounding problem"

Connected through hyperedge HE-4 (induced by source paper "song based classification techniques for endangered bird conservation"):
  with members:
    - "smote synthetic minority over sampling technique"

Connected through hyperedge HE-5 (induced by source paper "robust localization and tracking of simultaneous moving sound sources using beamforming and particle filtering"):
  with members:
    - "localization of simultaneous moving sound sources for mobile robot using a frequency domain steered beamformer approach"

Connected through hyperedge HE-6 (induced by source paper "localization of simultaneous moving sound sources for mobile robot using a frequency domain steered beamformer approach"):
  with members:
    - "microphone array post filter for separation of simultaneous non 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.RO(Robotics)