Papers by Domenic Di Francesco
A Stan model file describing the GP regression for the limit state in an FAD. This can be run fro... more A Stan model file describing the GP regression for the limit state in an FAD. This can be run from R or Python using any of the compatible the Stan interface libraries provided the necessary inputs are provided (as documented in the data block of the Stan file).
Stan code for Bayesian model for estimating corrosion growth rate allowing for probabilistic impu... more Stan code for Bayesian model for estimating corrosion growth rate allowing for probabilistic imputation of missing data and partial pooling of information between location.
Data-Centric Engineering
Attempts to formalize inspection and monitoring strategies in industry have struggled to combine ... more Attempts to formalize inspection and monitoring strategies in industry have struggled to combine evidence from multiple sources (including subject matter expertise) in a mathematically coherent way. The perceived requirement for large amounts of data are often cited as the reason that quantitative risk-based inspection is incompatible with the sparse and imperfect information that is typically available to structural integrity engineers. Current industrial guidance is also limited in its methods of distinguishing quality of inspections, as this is typically based on simplified (qualitative) heuristics. In this paper, Bayesian multi-level (partial pooling) models are proposed as a flexible and transparent method of combining imperfect and incomplete information, to support decision-making regarding the integrity management of in-service structures. This work builds on the established theoretical framework for computing the expected value of information, by allowing for partial poolin...
Volume 2B: Structures, Safety, and Reliability
In pipelines, pressure vessels and various other steel structures, the remaining thickness of a c... more In pipelines, pressure vessels and various other steel structures, the remaining thickness of a corroding ligament can be measured directly and repeatedly over time. Statistical analysis of these measurements is a common approach for estimating the rate of corrosion growth, where the uncertainties associated with the inspection activity are taken into account. An additional source of variability in such calculations is the epistemic uncertainty associated with the limited number of measurements that are available to engineers at any point in time. Traditional methods face challenges in fitting models to limited or missing datasets. In such cases, deterministic upper bound values, as recommended in industrial guidance, are sometimes assumed for the purpose of integrity management planning. In this paper, Bayesian inference is proposed as a means for representing available information in consistency with evidence. This, in turn, facilitates decision support in the context of risk-info...
Civil Engineering and Environmental Systems
ABSTRACT All engineering structures degrade or become damaged in service to some extent. Informat... more ABSTRACT All engineering structures degrade or become damaged in service to some extent. Information collection activities, such as inspection or structural health monitoring can reduce uncertainty in probabilistic models of structural condition. By linking the information that they provide to the improved integrity management strategies that they facilitate, their expected value can be quantified. This value of information can be obtained using Bayesian decision analysis. In this work an extended value of information model is presented that accounts for the risk associated with exposure to a hazardous environment. By evaluating this risk on the same scale as the risk of structural failure, the relationship between the expected quality of information and the number of staff-hours in a hazardous environment (such as an offshore oil and gas platform) is investigated. An example case study identifies the requirements regarding the precision, bias, and reliability of information from autonomous or remote inspection methods, for them to be considered as an optimal risk management strategy.
Reliability Engineering & System Safety
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Papers by Domenic Di Francesco