Simone Martini

Ahmed A. Elgohary, Rohan Palanikumar, Simone Martini et al.

In this letter, we report the first experimental demonstration of the recently emerged new paradigm in hovering and flapping flight physics called (Natural Hovering Extremum Seeking (NH-ES)) [doi.org/10.1103/4dm4-kc4g], which theorized that stable hovering flight physics observed in nature by flapping insects and hummingbirds can be generated via a model-free, real-time, computationally-basic, sensory-based feedback mechanism that only needs the built-in natural oscillations of the flapping wing as both the control and the propulsive input. We run experiments of moth-like, light source-seeking, on a flapping-wing body in a total model-free setting that is agnostic to morphological parameters and body/aerodynamic models. We show that the flapping body using NH-ES gains altitude and stabilizes autonomously the servos responsible for flapping, including with pitching dynamics (believed in literature to be a main reason of instability in open-loop hovering). The flapping body effectively/stably hovers about the light source, needing only feedback of local measurements of light intensity. Our results were also achieved under delay/noise effects, supporting earlier observations that NH-ES is robust against potential processing delays and noisy-sensations.

Michael Lodi, Marco Sbaraglia, Simone Martini

We report our experience of an extracurricular online intervention on cryptography principles in 10th grade. This paper's first goal is to present the learning path we designed, influenced by cryptography core ideas rather than technical knowledge. We will detail how we used Snap! (a visual programming language) to realize hands-on activities: programming playgrounds to experiment with cryptosystems and their limits, and interactive support for an unplugged activity on the Diffie-Hellman key exchange. The second goal is to evaluate our intervention in terms of both student perceptions and learning of core cryptography ideas. The students appreciated the course and felt that, despite being remote, it was fun, interesting, and engaging. They said the course helped them understand the role of cryptography, CS, and Math in society and sparked their interest, especially in cryptography and CS. The third goal is to discuss what worked well and areas of improvement. Pedagogically, remote teaching caused high "instructor blindness" and prevented us from giving the optimal amount of guidance during the exploration activities with Snap! playgrounds, making them sometimes too challenging for total programming novices. On the other hand, the "remote-unplugged" Diffie-Hellman worked well: it embodies a coherent metaphor that engaged the students and made them grasp this groundbreaking protocol. The students praised the activities as engaging, even when challenging. The final assessment showed that the core cryptography ideas were well understood.