Tutorial 1: Dynamic Multi-objective Optimization: Introduction, Challenges and Opportunities
Speaker: Mardé Helbig, Griffith University, Australia
Abstract: Most optimization problems in real-life have more than one objective, with at least two objectives in conflict with one another and at least one objective/constraint that changes over time. These kinds of optimization problems are referred to as dynamic multi-objective optimization (DMOO) problems (DMOPs). Instead of re-starting the optimization process after a change in the environment has occurred, previous knowledge is used and if the changes are small enough, this may lead to new solutions being found much quicker.
Most research in multi-objective optimization has been conducted on static problems and most research on dynamic problems has been conducted on single-objective optimization. The goal of a single-objective dynamic optimization algorithm is to find the most optimal solution and only one solution exists. However, due to the conflicting objectives of a DMOP, a single solution does not exist. Therefore, the goal of a DMOO algorithm (DMOA) is to find an optimal set of trade-off solutions that is as close as possible to the true set of solutions and that contains a diverse set of solutions (similar to static MOO). However, in addition to these goals a DMOA also has to track the changing set of optimal solutions over time. Therefore, the DMOA also has to deal with the problems of a lack of diversity and outdated memory (similar to dynamic single-objective optimization).

Outline of Tutorial:
This tutorial will introduce the participants to the field of DMOO by discussing:
·      benchmark functions and performance measures that have been proposed and the issues related to each of these
·      algorithms that have been proposed to solve DMOO
·      issues with the comparison of DMOAs’ performance and ensuring a fair comparison; analysing the performance of DMOAs and why traditional approaches used for static MOO is not necessarily adequate enough
·      challenges in the DMOO field that are not yet addressed, such as incorporating a decision maker’s preference in DMOO and visualizing the behavior of DMOAs
·      emerging research fields (such as many-objective optimization and fitness landscape analysis) that provide interesting research opportunities in the field of DMOO

Biography:  Mardé Helbig is a Senior Lecturer at the School of ICT at Griffith University in Australia. Her research focuses on solving dynamic multi-objective optimization (DMOO) problems using computational intelligence algorithms. She is the chair of the IEEE CIS Chapters sub-committee, co-chair of the IEEE CIS mentoring sub-committee, and a sub-committee member of the IEEE CIS Young Professionals and IEEE Women in CI. She has organised special sessions and presented tutorials and keynotes on DMOO at various conferences, including IEEE WCCI 2018 and GECCO 2021. She is the special sessions chair at SSCI2021. She is a member of the South African Young Academy of Science and has received the 2018/2019 TW Kambule-NSTF: Emerging Researcher award for her research in DMOO.