Occupational exoskeletons have the potential to prevent work-related musculoskeletal disorders. Their widespread adoption should be promoted by investigating their long-term innocuity, sustained effectiveness, and practicability. This article presents a six-months longitudinal study exploring effects of an arm support exoskeleton (ASE) on six male workers, examining potential side effects, ASE's effectiveness, and its integration into daily work practices. Monthly clinical visits were scheduled to monitor workers’ health. Effectiveness, usability and acceptance metrics were collected at the beginning of the study and after six months. No side effects were found in clinical metrics during the study. Significant reductions, consistent overtime, were observed in shoulder muscle activity (up to 30%) and in effort perception-related metrics (up to 2.4 out of 10 points). Usage time settled around 10% of the monthly work-shift and gradually decreased possibly due to external factors (e.g., social, motivational, and seasonal factors) beyond researchers' control. Results encourage the continuation of similar investigations to strengthen these findings and promote the use of occupational exoskeletons.

Concurrency in the Linux kernel can be a contentious topic. The Linux kernel mailing list features numerous discussions related to consistency models, including those of the more than 30 CPU architectures supported by the kernel and that of the kernel itself. How are Linux programs supposed to behave? Do they behave correctly on exotic hardware? A formal model can help address such questions. Better yet, an executable model allows programmers to experiment with the model to develop their intuition. Thus we offer a model written in the cat language, making it not only formal, but also executable by the herd simulator. We tested our model against hardware and refined it in consultation with maintainers. Finally, we formalised the fundamental law of the Read-Copy-Update synchronisation mechanism, and proved that one of its implementations satisfies this law.

This paper presents a realtime locomotion mode recognition method for an active pelvis orthosis. Five locomotion modes, including sitting, standing still, level-ground walking, ascending stairs, and descending stairs, are taken into consideration. The recognition is performed with locomotion information measured by the onboard hip angle sensors and the pressure insoles. These five modes are firstly divided into static modes and dynamic modes, and the two kinds are classified by monitoring the variation of the relative hip angles of the two legs within a pre-defined period. Static states are further classified into sitting and standing still based on the absolute hip angle. As for dynamic modes, a fuzzy-logic based method is proposed for the recognition. Two event-based locomotion features, including the hip joint angle at the first foot-strike and the center of foot pressure at the first foot-strike are used to calculate the membership of different modes based on the membership function, and the mode with the maximal membership is selected as the target mode. Experimental results with three subjects achieve an average recognition accuracy of 99.87% and average recognition delay of 18.12% of one gait cycle.

The response time analysis (RTA) is one of the fundamental tools used to guarantee the schedulability of sets of real-time tasks scheduled by Fixed Priorities. Also, several analysis methods inspired by RTA have been successfully developed to address more sophisticated execution platforms (distributed systems, multiprocessor) and application models (DAGs). The major issue with RTA is its time complexity, which is NP-hard. Such a complexity shows up when the task set has high utilization and RTA needs to check all jobs until the first idle instant. In this paper, we propose a continuous upper bound to the response time with quadratic time complexity in the number of tasks. Such an upper bound is demonstrated to be tighter than previously proposed ones with linear time complexity. In addition, with two tasks only, we prove that the proposed bound is the tightest continuous function upper bounding the exact response time of sets of tasks with full utilization. Whether or not this property holds with more than two tasks is still an open problem.