Optimality of broken extremals

In this paper we analyse the optimality of broken Pontryagin extremal for an n-dimensional affine control system with a control parameter, taking values in a k- dimensional closed ball. We prove the optimality of broken normal extremals when n = 3 and the controllable vector fields form a contact distribution, and when the Lie algebra of the controllable fields is locally orthogonal to the singular locus and the drift does not belong to it. Moreover, if k = 2, we show the optimality of any broken extremal even abnormal when the controllable fields do not form a contact distribution in the point of singularity.Comment: arXiv admin note: text overlap with arXiv:1610.0675

Simplified risk model for waste management and environmental restoration activities

A Simplified Risk Model (SRM) is being developed to support environmental restoration and waste management (EM) planning activities. The SRM is designed to be able to quantitatively estimate risk for various EM alternatives within hours or days, given limited information about the processes covered within the alternative. The risk model covers radiological, chemical, and industrial risk from both accidents and normal, incident free operations. A simple risk equation is used to model accident risk. Normal, incident free operation risk is modeled using a multiplier on accident risk. Ongoing applications of the SRM are expected to lead to significant improvements to the model in the near future

The MAP-HAND : psychometric properties and differences in activity performance between patients with carpometacarpal osteoarthritis and rheumatoid arthritis

Objective: To assess construct validity (Rasch analyses) of the Measure of Activity Performance of the Hand (MAP-Hand) in people with carpometacarpal osteoarthritis (CMC1 OA), and to explore differences in activity performance between people with CMC1 OA and those with rheumatoid arthritis. Design: Cross-sectional study. Subjects: A total of 180 people with CMC1 OA referred for surgical consultation were recruited from rheumatology clinics in Norway, and 340 people with rheumatoid arthritis were recruited from outpatient rheumatology clinics in the UK. Methods: The MAP-Hand consists of 18 predefined items scored on a 4-point scale from 1 (no difficulty) to 4 (unable to do), from which a mean score is calculated. Construct validity was assessed using Rasch analyses. Differences between the 2 groups were assessed using an independent sample t-test at the group level and differential item functioning (condition as grouping variable) at the item level. Results: Some mis-targeting of data and clusters of dependency were found, but the MAP-Hand scores showed an overall fit to the model. No between group difference in total mean MAP-Hand score was found, but there were significant differences between the 2 groups on item levels. Conclusion: The MAP-Hand showed satisfactory construct validity and could differentiate between people with CMC1 OA and those with rheumatoid arthritis on item levels