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: "enabling wifi p2p based pedestrian safety app"
  Abstract: Recent studies reported a significant increase in the number of accidents caused by distracted walking. In this paper, we develop a mobile system that provides a timely warning to the pedestrian and the driver to reduce the chance of pedestrian-involved accidents. The proposed system performs pedestrian risk assessment to estimate the collision probability based on accurate user localization, user-phone-viewing event detection, and WiFi P2P-based vehicle to pedestrian communication. Depending on the resulting collision probability, the pedestrian (and the driver) is alerted to prevent accidents. The proposed system is implemented on a COTS smartphone, and experiments are conducted in a department parking lot. Experimental results demonstrate that it effectively calculates the collision probability and sends accordingly an alert message to the user in a timely manner leveraging its improved positioning accuracy, energy efficiency, and effective user context awareness.

Connected through hyperedge HE-1 (induced by source paper "deepwalking enabling smartphone based walking speed estimation using deep learning"):
  with members:
    - "idnet smartphone based gait recognition with convolutional neural networks"
    - "mobile stride length estimation with deep convolutional neural networks"

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)