Finite-dimensional characterisation of optimal control laws over an infinite horizon for nonlinear systems

Infinite-horizon optimal control problems for nonlinear systems are considered. Due to the nonlinear and intrinsically infinite-dimensional nature of the task, solving such optimal control problems is challenging. In this paper an exact finite-dimensional characterisation of the optimal solution over the entire horizon is proposed. This is obtained via the (static) minimisation of a suitably defined function of (projected) trajectories of the underlying Hamiltonian dynamics on a hypersphere of fixed radius. The result is achieved in the spirit of the so-called shooting methods by introducing, via simultaneous forward/backward propagation, an intermediate shooting point much closer to the origin, regardless of the actual initial state. A modified strategy allows one to determine an arbitrarily accurate approximate solution by means of standard gradient-descent algorithms over compact domains. Finally, to further increase robustness of the control law, a receding-horizon architecture is envisioned by designing a sequence of shrinking hyperspheres. These aspects are illustrated by means of a benchmark numerical simulation

Transmission of SARS-CoV-2 and Other Infections at Large Sports Gatherings: A Surprising Gap in Our Knowledge

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E-Liquid Autofluorescence can be used as a Marker of Vaping Deposition and Third-Hand Vape Exposure

In the past 5 years, e-cigarette use has been increasing rapidly, particularly in youth and young adults. Due to the novelty of e-cigarettes (e-cigs) and e-cigarette liquids (e-liquids), research on their chemo-physical properties is still in its infancy. Here, we describe a previously unknown and potentially useful property of e-liquids, namely their autofluorescence. We performed an emission scan at 9 excitation wavelengths common to fluorescent microscopy and found (i) that autofluorescence differs widely between e-liquids, (ii) that e-liquids are most fluorescent in the UV range (between 350 and 405 nm) and (iii) fluorescence intensity wanes as the emission wavelength increases. Furthermore, we used the autofluorescence of e-liquids as a marker for tracking e-cig aerosol deposition in the laboratory. Using linear regression analysis, we were able to quantify the deposition of a "vaped" e-liquid onto hard surfaces. Using this technique, we found that every 70 mL puff of an e-cigarette deposited 0.019% e-liquid (v/v) in a controlled environment. Finally, we vaped a surface in the laboratory and used our method to detect e-cig aerosol third-hand exposure. In conclusion, our data suggest that e-cigarette autofluorescence can be used as a marker of e-cigarette deposition

Model matching and passivation of MIMO linear systems via dynamic output feedback and feedforward

A model matching and passivating control architecture for multi-input/multi-output linear systems, comprising dynamic feedback and feedforward, is proposed. The approach-essentially without any restriction on the relative degree and the zeros of the underlying system and by relying only on input/output measurements-provides a closed-loop system, the transfer matrix of which matches any desired matrix of rational functions. An alternative implementation of the above design allows to achieve an arbitrary approximation accuracy of a desired transfer matrix while also preserving structural properties-in particular observability-of the overall interconnected system. Such a construction can be then specialized to provide input/output decoupling or a system that is passive from a novel control input to a modified output. The result is achieved by arbitrarily assigning the relative degree and location of the poles and zeros on the complex plane of the interconnected system in a systematic way. It is also shown that similar ideas can be employed to enforce a desired, arbitrarily small, L 2 -gain from an unknown disturbance input to a modified output, while preserving the corresponding gain from the control input to the same output. The article is concluded with applications and further discussions on the results

Interprofessional Collaboration and Diabetes Management in Primary Care: A Systematic Review and Meta-Analysis of Patient-Reported Outcomes

The global spread of diabetes poses serious threats to public health requiring a patient-centered approach based both on interprofessional collaboration (IPC) given by the cooperation of several different health professionals, and patients’ perspective through the assessment of Patient-Reported Outcomes (PROs). The aim of the present study is to evaluate the impact of interprofessional collaboration interventions, for the management of type 2 diabetes in primary care settings, through PROs. A systematic review and meta-analysis was conducted querying the PubMed, Scopus and Embase databases. Out of the 1961 papers initially retrieved, 19 met the inclusion criteria. Interprofessional collaboration is significantly associated with an increase in both patient’s satisfaction (SMD 0.32 95% CI 0.05–0.59) and in the mental well-being component of the HRQoL (SMD 0.18; 95% CI 0.06–0.30), and there was also promising evidence supporting the association between an interprofessional approach and an increase in self-care and in generic and specific quality-of-life. No statistical differences were found, supporting the positive impact on IPC interventions on the physical component of the HRQoL, depression, emotional distress, and self-efficacy. In conclusion, the effect of IPC impacts positively on the few areas assessed by PROMs. Policymakers should promote the widespread adoption of a collaborative approach as well as to endorse an active engagement of patients across the whole process of care