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: "Condition-based dynamic maintenance operations planning & grouping. Application to commercial heavy vehicles"
  Abstract: This paper aims at presenting a method to optimize the maintenance planning for a commercial heavy vehicle. Such a vehicle may be considered as a multi-components system. Grouping maintenance operations related to each component reduces the global maintenance cost of the system. Classically, the optimization problem is solved using a priori reliability characteristics of components. Two types of methods may be used, i.e. static or dynamic methods. Static methods provide a fixed maintenance planning, whereas dynamic methods redefine the groups of maintenance operations at each decision time. Dynamic procedures can incorporate component information such as component states or detected failures. For deteriorating systems, reliability characteristics of each component may be estimated thanks to deterioration models and may be updated when a degradation measure is available. This additional information on degradation features allows to better follow the real state of each component and to improve the maintenance planning.

Connected through hyperedge HE-1 (induced by source paper "Minimising the total cost of renewal and risk of water infrastructure assets by grouping renewal interventions"):
  with members:
    (none)

Connected through hyperedge HE-2 (induced by source paper "A survey of the application of gamma processes in maintenance"):
  with members:
    - "On the use of on-line detection for maintenance of gradually deteriorating systems"

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: Engineering