title: Compositional synthesis of maximally permissive supervisors using supervision equivalence

authors: Flordal, Hugo

subjects: computer science

abstract: This paper presents a general framework for efficient synthesis of supervisors for discrete event systems. The approach is based on compositional minimisation, using concepts of process equivalence. In this context, a large number of ways are suggested how a finite-state automaton can be simplified such that the results of supervisor synthesis are preserved. The proposed approach yields a compact representation of a least restrictive supervisor that ensures controllability and nonblocking. The method is demonstrated on a simple manufacturing example to significantly reduce the number of states constructed for supervisor synthesis.

text: Compositional synthesis of maximally permissive supervisors using supervision equivalence This paper presents a general framework for efficient synthesis of supervisors for discrete event systems. The approach is based on compositional minimisation, using concepts of process equivalence. In this context, a large number of ways are suggested how a finite-state automaton can be simplified such that the results of supervisor synthesis are preserved. The proposed approach yields a compact representation of a least restrictive supervisor that ensures controllability and nonblocking. The method is demonstrated on a simple manufacturing example to significantly reduce the number of states constructed for supervisor synthesis.

year: 2007

title: Improving robustness of image recognition through artificial image augmentation

authors: Herbert, Callum

subjects: Deep learning

abstract: Deep learning based computer vision technologies can offer a number of advantages over manual labour inspection methods such as reduced operational costs and efficiency improvements. However, they are known to be unreliable in certain situations, especially when input images contain augmentations such as occlusion or distortion that computer vision models have not been trained on. While augmentations can be mitigated by controlling some situations, this is not always possible, especially in outdoor environments.

To address this issue, one common approach is supplemental robustness training using augmented training data, which involves training models on images containing the expected augmentations to improve performance. However, this approach requires collection of a substantial volume of augmented images for each expected augmentation, making it time-consuming and costly depending on the difficulty involved in reproducing each augmentation.
This thesis explores the viability of using artificially rendered augmentations on unaugmented images as a substitute for the manual collection and preparation of naturally augmented data for image recognition and object detection models. Specifically, this thesis recreates nine environmental augmentations that commonly occur within outdoor environments and evaluates their impact on model performance on three datasets.
The findings of this thesis indicate potential for using artificially generated augmentations as substitutes for naturally occurring augmentations. It is anticipated that further research in this area will enable more reliable image recognition and object detection in less controllable environments, thus improving the results of these technologies in uncertain situations.

text: Improving robustness of image recognition through artificial image augmentation Deep learning based computer vision technologies can offer a number of advantages over manual labour inspection methods such as reduced operational costs and efficiency improvements. However, they are known to be unreliable in certain situations, especially when input images contain augmentations such as occlusion or distortion that computer vision models have not been trained on. While augmentations can be mitigated by controlling some situations, this is not always possible, especially in outdoor environments.

To address this issue, one common approach is supplemental robustness training using augmented training data, which involves training models on images containing the expected augmentations to improve performance. However, this approach requires collection of a substantial volume of augmented images for each expected augmentation, making it time-consuming and costly depending on the difficulty involved in reproducing each augmentation.
This thesis explores the viability of using artificially rendered augmentations on unaugmented images as a substitute for the manual collection and preparation of naturally augmented data for image recognition and object detection models. Specifically, this thesis recreates nine environmental augmentations that commonly occur within outdoor environments and evaluates their impact on model performance on three datasets.
The findings of this thesis indicate potential for using artificially generated augmentations as substitutes for naturally occurring augmentations. It is anticipated that further research in this area will enable more reliable image recognition and object detection in less controllable environments, thus improving the results of these technologies in uncertain situations.

year: 2023

title: Māori men and the indirect procurement and sharing of prescription medications

authors: Hodgetts, Darrin

subjects: Māori men

abstract: Māori men have higher rates of many diseases and lower life expectancy than other population groups in New Zealand. The general consensus is that these health inequalities are due to the inequitable distribution of the social determinants of health; for example, education, employment, income and housing, and were largely driven by colonization and the social and economic marginalization of Māori. Health care factors, including reluctance to consult doctors or late presentation, are part of this equation, but do not fully explain the disparities in health between Māori men and other population groups. As part of our ongoing work in this area, we draw on a focus group discussion with seven Māori community health workers to provide a preliminary analysis of how some Māori people access and use medications. Particular attention is given to the emergent practice of Māori women presenting to general practitioners (GPs) with proxy symptoms to obtain medications for their male partners. This practice exemplifies a range of strategies that some whānau (family) have developed to navigate the health system and overcome the reluctance of some men to engage with the medical profession. The practice raises issues relating to the nature of “primary” and “whānau” care, accessibility of medical services and medications, adherence to medication regimes and the dynamics of doctor–patient relations.

text: Māori men and the indirect procurement and sharing of prescription medications Māori men have higher rates of many diseases and lower life expectancy than other population groups in New Zealand. The general consensus is that these health inequalities are due to the inequitable distribution of the social determinants of health; for example, education, employment, income and housing, and were largely driven by colonization and the social and economic marginalization of Māori. Health care factors, including reluctance to consult doctors or late presentation, are part of this equation, but do not fully explain the disparities in health between Māori men and other population groups. As part of our ongoing work in this area, we draw on a focus group discussion with seven Māori community health workers to provide a preliminary analysis of how some Māori people access and use medications. Particular attention is given to the emergent practice of Māori women presenting to general practitioners (GPs) with proxy symptoms to obtain medications for their male partners. This practice exemplifies a range of strategies that some whānau (family) have developed to navigate the health system and overcome the reluctance of some men to engage with the medical profession. The practice raises issues relating to the nature of “primary” and “whānau” care, accessibility of medical services and medications, adherence to medication regimes and the dynamics of doctor–patient relations.

year: 2011