human: Given a node-centered hypergraph: <hypergraph>, where nodes represent authors and hyperedges represent groups of authors who co-authored the same paper.

Details of the hypergraph:
Center node: "Characterization of Vehicle-to-Vehicle Radio Channels from Measurements at 5.2 GHz"
  Abstract: The development of efficient vehicle-to-vehicle (V2V) communications systems requires an understanding of the underlying propagation channels. In this paper, we present results on pathloss, power-delay profiles (PDPs), and delay-Doppler spectra from a high speed measurement campaign on a highway in Lund, Sweden. Measurements were performed at a carrier frequency of 5.2 GHz with the communicating vehicles traveling on the highway in opposite directions. A pathloss coefficient of 1.8 shows the best fit in the mean square sense with our measurement. The average root mean square (RMS) delay spread is between 263 ns and 376 ns, depending on the noise threshold. We investigate and describe selected paths in the delay-Doppler domain, where we observe Doppler shifts of more than 1,000 Hz.

Connected through hyperedge HE-1 (induced by source paper "Connectivity Analysis of Vehicular Ad Hoc Networks from a Physical Layer Perspective"):
  with members:
    - "Review of geographic forwarding strategies for inter-vehicular communications from mobility and environment perspectives"

Connected through hyperedge HE-2 (induced by source paper "Identification of time-variant directional mobile radio channels"):
  with members:
    - "Unitary ESPRIT: how to obtain increased estimation accuracy with a reduced computational burden"

Question: Please tell me which research area the center author belongs to. The 4 classes are: Computer science, Mathematics, Engineering, Economics, Psychology, Business. Directly output the class name.

gpt: Computer science