Prof Andreas Ernst

Research Overview

I have worked in Operations Research, particularly real-world applications of optimisation for over 25 years. This has included work in supply chains, logistics, mining, services (rostering) and energy. Current applied research includes a Linkage grant with Pacific National on rail planning & scheduling, and working as a lead researcher in the Australia Indonesia Centre on the Transport, Logistics & Supply Chain section of the PAIR program.

From a methodological perspective, my interest is particularly in solving large-scale integer programming problems using matheuristics: hybrid methods that combine ideas from integer programming such as decomposition methods with meta-heuristic optimisation. Examples of these include the Lagrangian Particle Swarm Optimisation method & Merge Search. These approaches have proven highly effective in practice but have not yet been sufficiently studied from an academic perspective. Recently have started working on ways to combine such approached with ideas from Machine Learning as part of an ARC Grant (joint work with RMIT). I have also worked on some more abstract discrete optimisation problems. Most significantly on hub location problems, where I have worked with long term collaborator Mohan Krishnamoorthy over many years. I continue to be interested in ways to make such models both more realistic and easier to solve.

Selected Publications

[1] Mokhtar, Hamid ; Krishnamoorthy, Mohan ; Ernst, Andreas T. "The 2-allocation p-hub median problem and a modified Benders decomposition method for solving hub location problem". In: Computers and Operations Research. 2019 ; Vol. 104. pp. 375-393. https://doi.org/10.1016/j.cor.2018.09.006

[2] Sun, Yuan ; Li, Xiaodong ; Ernst, Andreas T. "Using Statistical Measures and Machine Learning for Graph Reduction to Solve Maximum Weight Clique Problems". In: IEEE transactions on pattern analysis and machine intelligence. 2019. https://doi.org/10.1109/TPAMI.2019.2954827

[3] Mokhtar, Hamid ; Redi, A. A.N.Perwira ; Krishnamoorthy, Mohan ; Ernst, Andreas T. "An intermodal hub location problem for container distribution in Indonesia". In: Computers and Operations Research. 2019 ; Vol. 104. pp. 415-432. https://doi.org/10.1016/j.cor.2018.08.012

[4] Kulkarni, Sarang ; Krishnamoorthy, Mohan ; Ranade, Abhiram ; Ernst, Andreas T. ; Patil, Rahul. "A new formulation and a column generation-based heuristic for the multiple depot vehicle scheduling problem". In: Transportation Research Part B. 2018 ; Vol. 118. pp. 457-487. https://doi.org/10.1016/j.trb.2018.11.007

[5] Ernst, Andreas Tilman. "A hybrid Lagrangian Particle Swarm Optimization Algorithm for the degree-constrained minimum spanning tree problem". 2010 IEEE Congress on Evolutionary Computation (CEC). editor / Hisao Ishibuchi. Piscataway NJ USA : IEEE, Institute of Electrical and Electronics Engineers, 2010. pp. 1 - 8. https://doi.org/10.1109/CEC.2010.5585939