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: "SLA-based admission control for a Software-as-a-Service provider in Cloud computing environments"
  Abstract: Software as a Service (SaaS) provides access to applications to end users over the Internet without upfront investment in infrastructure and software. To serve their customers, SaaS providers utilise resources of internal data centres or rent resources from a public Infrastructure as a Service (IaaS) provider. In-house hosting can increase administration and maintenance costs whereas renting from an IaaS provider can impact the service quality due to its variable performance. To overcome these limitations, we propose innovative admission control and scheduling algorithms for SaaS providers to effectively utilise public Cloud resources to maximize profit by minimizing cost and improving customer satisfaction level. Furthermore, we conduct an extensive evaluation study to analyse which solution suits best in which scenario to maximize SaaS [email protected]?s profit. Simulation results show that our proposed algorithms provide substantial improvement (up to 40% cost saving) over reference ones across all ranges of variation in QoS parameters.

Connected through hyperedge HE-1 (induced by source paper "Quality of service approaches in cloud computing"):
  with members:
    - "A fair multi-attribute combinatorial double auction model for resource allocation in cloud computing"

Connected through hyperedge HE-2 (induced by source paper "Cloud computing — Issues, research and implementations"):
  with members:
    - "Scientific Workflow Management and the Kepler System"
    - "A Layered Security Approach for Cloud Computing Infrastructure"

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: Mathematics