Combinatorial Optimisation:Relaxation, Duality and Heuristics

Mansoor, M Hasan (2022) Combinatorial Optimisation:Relaxation, Duality and Heuristics. PhD thesis, UNSPECIFIED.

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Abstract

Relaxation and dual-based heuristics have been a part of research in combinatorial optimisation since the early 1970s. This thesis extends that strand of research into less popular forms of relaxations in particular surrogate relaxation, which is theoretically a tighter relaxation than the two most common relaxations (Linear Programming and Lagrangian relaxations). The aim is to show surrogate dual information can add to the performance of dual-based matheuristics. In chapter 2 we provide some theoretical results related to surrogate and group relaxation. We follow it up with an exact and a heuristic surrogate dual method along with computation results, in chapters 3 and 4 respectively. Finally, in chapter 5, we take a step back and seek to make an introductory empirical investigation into the value of good and better dual solutions in guiding primal heuristics using LP relaxation as an example.

Item Type:
Thesis (PhD)
Uncontrolled Keywords:
Lancaster University Keywords/lums_keywords
Subjects:
ID Code:
173786
Deposited By:
Deposited On:
29 Jul 2022 12:30
Refereed?:
No
Published?:
Published
Last Modified:
06 Oct 2022 01:06