2 resultados para soft-commutation technique
em AMS Tesi di Dottorato - Alm@DL - Università di Bologna
Resumo:
This dissertation consists of three papers. The first paper "Managing the Workload: an Experiment on Individual Decision Making and Performance" experimentally investigates how decision-making in workload management affects individual performance. I designed a laboratory experiment in order to exogenously manipulate the schedule of work faced by each subject and to identify its impact on final performance. Through the mouse click-tracking technique, I also collected interesting behavioral measures on organizational skills. I found that a non-negligible share of individuals performs better under externally imposed schedules than in the unconstrained case. However, such constraints are detrimental for those good in self-organizing. The second chapter, "On the allocation of effort with multiple tasks and piecewise monotonic hazard function", tests the optimality of a scheduling model, proposed in a different literature, for the decisional problem faced in the experiment. Under specific assumptions, I find that such model identifies what would be the optimal scheduling of the tasks in the Admission Test. The third paper "The Effects of Scholarships and Tuition Fees Discounts on Students' Performances: Which Monetary Incentives work Better?" explores how different levels of monetary incentives affect the achievement of students in tertiary education. I used a Regression Discontinuity Design to exploit the assignment of different monetary incentives, to study the effects of such liquidity provision on performance outcomes, ceteris paribus. The results show that a monetary increase in the scholarships generates no effect on performance since the achievements of the recipients are all centered near the requirements for non-returning the benefit. Secondly, students, who are actually paying some share of the total cost of college attendance, surprisingly, perform better than those whose cost is completely subsidized. A lower benefit, relatively to a higher aid, it motivates students to finish early and not to suffer the extra cost of a delayed graduation.
Resumo:
Nowadays, one of the most ambitious challenges in soft robotics is the development of actuators capable to achieve performance comparable to skeletal muscles. Scientists have been working for decades, inspired by Nature, to mimic both their complex structure and their perfectly balanced features in terms of linear contraction, force-to-weight ratio, scalability and flexibility. The present Thesis, contextualized within the FET open Horizon 2020 project MAGNIFY, aims to develop a new family of innovative flexible actuators in the field of soft-robotics. For the realization of this actuator, a biomimetic approach has been chosen, drawing inspiration from skeletal muscle. Their hierarchical fibrous structure was mimicked employing the electrospinning technique, while the contraction of sarcomeres was designed employing chains of molecular machines, supramolecular systems capable of performing movements useful to execute specific tasks. The first part deals with the design and production of the basic unit of the artificial muscle, the artificial myofibril, consisting in a novel electrospun core-shell nanofiber, with elastomeric shell and electrically conductive core, coupled with a conductive coating, for the realization of which numerous strategies have been investigated. The second part deals instead with the integration of molecular machines (provided by the project partners) inside these artificial myofibrils, preceded by the study of several model molecules, aimed at simulating the presence of these molecular machines during the initial phases of the project. The last part concerns the realization of an electrospun multiscale hierarchical structure, aimed at reproducing the entire muscle morphology and fibrous organization. These research will be joined together in the near future like the pieces of a puzzle, recreating the artificial actuator most similar to biological muscle ever made, composed of millions of artificial myofibrils, electrically activated in which the nano-scale movement of molecular machines will be incrementally amplified to the macro-scale contraction of the artificial muscle.