Global existence for a singular phase field system related to a sliding mode control problem

In the present contribution we consider a singular phase field system located in a smooth and bounded three-dimensional domain. The entropy balance equation is perturbed by a logarithmic nonlinearity and by the presence of an additional term involving a possibly nonlocal maximal monotone operator and arising from a class of sliding mode control problems. The second equation of the system accounts for the phase dynamics, and it is deduced from a balance law for the microscopic forces that are responsible for the phase transition process. The resulting system is highly nonlinear; the main difficulties lie in the contemporary presence of two nonlinearities, one of which under time derivative, in the entropy balance equation. Consequently, we are able to prove only the existence of solutions. To this aim, we will introduce a backward finite differences scheme and argue on this by proving uniform estimates and passing to the limit on the time step.Comment: Key words: Phase field system; maximal monotone nonlinearities; nonlocal terms; initial and boundary value problem; existence of solution

A shift in mindset can keep you from discarding digital innovation projects too soon

If your organisation has – like so many others – a history of shelved digital innovation projects, you might want to ask yourself if you have looked close enough at the true value of these projects. Verena Stingl and Michele Colli suggest a shift in perspective, to explore the extended and innovative potential of your technology pilots, before binning them prematurely

Digital Transformation Strategies for Achieving Operational Excellence: a Cross-Country Evaluation

The last decade, the manufacturing industry has been concerned with digital transformation as a new lever for competitiveness. Nevertheless, the industrial digital transformation remains an emerging topic, which is not well understood academically and in terms of its practical implications. Due to different contextual factors and national development policies, companies from different countries adopted different strategies for supporting it. These often led to peculiar effects on the companies’ operations. This paper is investigating how four large manufacturers - two from Italy and two from Denmark – are strategically addressing this agenda. The aim of this research is to offer a perspective on technology transformation in diverse contexts by studying the different digital transformation strategies adopted by these companies and discussing their dependencies on contextual factors

Cardiac kinematic parameters computed from video of in situ beating heart

Mechanical function of the heart during open-chest cardiac surgery is exclusively monitored by echocardiographic techniques. However, little is known about local kinematics, particularly for the reperfused regions after ischemic events. We report a novel imaging modality, which extracts local and global kinematic parameters from videos of in situ beating hearts, displaying live video cardiograms of the contraction events. A custom algorithm tracked the movement of a video marker positioned ad hoc onto a selected area and analyzed, during the entire recording, the contraction trajectory, displacement, velocity, acceleration, kinetic energy and force. Moreover, global epicardial velocity and vorticity were analyzed by means of Particle Image Velocimetry tool. We validated our new technique by i) computational modeling of cardiac ischemia, ii) video recordings of ischemic/reperfused rat hearts, iii) videos of beating human hearts before and after coronary artery bypass graft, and iv) local Frank-Starling effect. In rats, we observed a decrement of kinematic parameters during acute ischemia and a significant increment in the same region after reperfusion. We detected similar behavior in operated patients. This modality adds important functional values on cardiac outcomes and supports the intervention in a contact-free and non-invasive mode. Moreover, it does not require particular operator-dependent skills