Thread by @AMLehikoinen

PhD thesis examination of Liangliang Lu has started. Exciting! I'll try live tweeting first time. Let's see how it goes. :) @MerikotkaCentre @AaltoENG

By the means modelling, the thesis contributes to advancing the #riskmanagement of #oil spills in
ice conditions, focusing on #pollution #preparedness and response.

First the system that generates the risk (Accident -> Collision & oil outflow -> oil drifting -> response and recovery) is developed. It is then used to identify critical factors related to (a) the accident aspects and (b) the response aspect.

The thesis focuses on the response aspect, specifically analysing the operability of reponse vessels in ice.. An operability index and map has been developed.

Opponent Prof. Zaili Yang, School of Engineering, Liverpool John Moores University, UK: "What aspects have not been studied in the oil spill risk literature?"

Lu: Accident analyses especially in icy conditions could be more numerous and more detailed. Also, more accurate models on ice mechanisms would be needed - to better understand the ice. Understanding is also lacking concerning the effects of low temperatures...

: how does the temperature affect the collisions and the behavior of oil? In addition, not many quantitative analyses on the effects of oil on the marine biota in arctic areas. One gap is also the lack of holistic approaches, from causes of oil accidents to their consequences.

Important to know more about how sensitive the marine organisms are and where their habitats are located. One important gap is also the lack of economic analysis concerning the consequences of oil spills.

Opponent thinks Lu have done excellent work with applying #BayesianNetwork to model the oil accident system. Question: How have you validated the causal qualitative structure of the model?

Lu: The structure is based on the literature and several expert interviews. Checking, whether these match with each other.
Opponent: Thus you have been continuously using experts until you feel no more rounds are needed, but the structure is strong / valid enough. This is good.

Opponent and Lu talk about validation methods available for Bayesian Network models in the field of risk analysis.: Comparisons to realistic data, if available. If not, comparing the results with literature and checking their match within the comparable ranges.

Lu explains the oil response vessel operability index he has developed. The index is primarily based on environmental conditions, specifically ice thickness and ice drift speed.

Opponent praised Lu for an excellent Conclusions section. Asked how Lu would continue from where the PhD work ended. Lu: How to rate the quality of evidence available? Also, put effort on analysing also the causes of the accidents (as he now has focused on the response aspects)..

... Also, he would like to study the opportunities provided by the e-navigation and web-based decision support solutions in this context: how they could support the navigation and prevent accidents.

The opponent stated that the PhD work of Lianliang Lu is of good quality, meeting all the criteria and covers all the aspects required from a doctoral thesis. Proposes Lu to be awarded the title of PhD. CONGRATULATIONS Lianliang!

The custos, Prof. @penttikujala closed the defence at 13:40.

This is not a comprehensive report. Some of my time went with tweeting. :) Those who were present, please feel free to add material or correct potential misunderstandings of mine!

Congratulations also to the supervisor @penttikujala and the advisors @FlorisGoerlandt and @OsirisValdezB !

The thesis summary is available behind this link:
aaltodoc.aalto.fi/handle/1234567…