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: "The vacuum: facilitating the manipulation of distant objects"
  Abstract: We present the design and evaluation of the vacuum, a new interaction technique that enables quick access to items on areas of a large display that are difficult for a user to reach without significant physical movement. The vacuum is a circular widget with a user controllable arc of influence that is centered at the widget's point of invocation and spans out to the edges of the display. Far away objects residing inside this influence arc are brought closer to the widget's centre in the form of proxies that can be manipulated in lieu of the original. We conducted two experiments which compare the vacuum to direct picking and an existing technique called drag-and-pick [2]. Results show that the vacuum outperforms existing techniques when selecting multiple targets in a sequence, performs similarly to existing techniques when selecting single targets located moderately far away, and slightly worse with single targets located very far away in the presence of distracter targets along the path.

Connected through hyperedge HE-1 (induced by source paper "Acquisition of Animated and Pop-Up Targets"):
  with members:
    (none)

Connected through hyperedge HE-2 (induced by source paper "Stitching: pen gestures that span multiple displays"):
  with members:
    - "Fine-grained network time synchronization using reference broadcasts"
    - "Gestures without libraries, toolkits or training: a $1 recognizer for user interface prototypes"

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