Computational Thinking, Between Papert and Wing

International audienceThe pervasiveness of Computer Science (CS) in today’s digital society and the extensive use of computational methods in other sciences call for its introduction in the school curriculum. Hence, Computer Science Education is becoming more and more relevant. In CS K-12 education, computational thinking (CT) is one of the abused buzzwords: different stakeholders (media, educators, politicians) give it different meanings, some more oriented to CS, others more linked to its interdisciplinary value. The expression was introduced by two leading researchers, Jeannette Wing (in 2006) and Seymour Papert (much early, in 1980), each of them stressing different aspects of a common theme. This paper will use a historical approach to review, discuss, and put in context these first two educational and epistemological approaches to CT. We will relate them to today’s context and evaluate what aspects are still relevant for CS K-12 education. Of the two, particular interest is devoted to “Papert’s CT,” which is the lesser-known and the lesser-studied. We will conclude that “Wing’s CT” and “Papert’s CT,” when correctly understood, are both relevant to today’s computer science education. From Wing, we should retain computer science’s centrality, CT being the (scientific and cultural) substratum of the technical competencies. Under this interpretation, CT is a lens and a set of categories for understanding the algorithmic fabric of today’s world. From Papert, we should retain the constructionist idea that only a social and affective involvement of students into the technical content will make programming an interdisciplinary tool for learning (also) other disciplines. We will also discuss the often quoted (and often unverified) claim that CT automatically “transfers” to other broad 21st century skills. Our analysis will be relevant for educators and scholars to recognize and avoid misconceptions and build on the two core roots of CT

An in-line coaxial-to-waveguide transition for q-band single-feed-per-beam antenna systems

An in-line transition between a coaxial cable and rectangular waveguide operating in Q-band (33–50 GHz) is presented. The aim of the work is to minimize the modifications in the waveguide to the strictly necessary to overcome the manufacturing issues due to the high frequencies involved. In addition, the transition is compact and it does not increase the space occupation on the transverse section, this suggests its application in horn antennas clusters arrangement. The operating principle consists of both a modal conversion and an impedance matching between the devices. The modal conversion is realized in an intermediate region, where the coaxial penetrates in the waveguide: the device geometry is designed so that the electric field in the transition is a trade-off between the TEM mode of the coaxial and the TE10 of the guide. A shaped waveguide backshort and a reactive air gap in the coaxial cable co-participate to achieve the matching. An optimized Chebyshev stepped transformer completes the transition to fulfil the impedance mismatch with the full waveguide. The design issues and technological aspects are considered. The influences of the feeding pin misalignment, the presence of groove is included in the analysis and these practical aspects are discussed and numerically validated via the scattering parameters analysis of the proposed design. The return loss is higher than 25 dB over the whole Q-band

Programmare per imparare la crittografia al Liceo Matematico

Descriviamo un corso di introduzione alle “grandi idee” della crittografia, pensato per il secondo anno del Liceo Matematico. Sua caratteristica fondamentale è l’approccio “per scoperta”: viene proposta una successione di crittosistemi (dai classici ai più moderni), di ciascuno dei quali lo studente puó sperimentare caratteristiche, possibili attacchi e limi- ti, sentendo la necessità di scoprire il successivo. Abbiamo usato Snap! (un linguaggio di programmazione visuale a blocchi) sia per costruire dei playground (linguaggi di pro- grammazione task-specific, con una ridottissima selezione mirata di istruzioni) con cui spe- rimentare i diversi schemi, sia per guidare un’attività unplugged sul protocollo di Diffie- Hellman. Il lavoro presenta in dettaglio il percorso, le attività e il materiale, nonché una prima valutazione dell’intervento didattico, condotta dopo due edizioni (la prima online e la seconda in presenza)

Cryptography in Grade 10: Core Ideas with Snap! and Unplugged

International audienceWe report our experience of an extracurricular online intervention on cryptography in Grade 10. Our first goal is to describe how we taught some fundamental cryptography ideas by making students encounter a progression of representative cryptosystems, from classical to modern, and discover their characteristics and limitations. We used Snap! (a visual programming language) to realize hands-on activities: block-programming playgrounds (a form of task-specific programming languages) to experiment with cryptosystems, and an interactive app to support an unplugged (albeit remote) Diffie-Hellman key agreement. After experimenting with each system, the students were involved in a Socratic discussion on how to overcome the discovered limitations, motivating the introduction of the following system in our path. Our second goal is to evaluate the students' perceptions and learning of cryptography core ideas. They appreciated the course and felt that, despite being remote, it was fun and engaging. According to the students, the course helped them understand the role of cryptography, CS, and Math in society and sparked their interest in cryptography and CS. The final assessment showed that the students well understood the cryptography ideas addressed. Our third goal is to discuss what worked and areas of improvement. The "remote-unplugged" Diffie-Hellman, where the meeting chat was a metaphor for the public channel, engaged the students in understanding this groundbreaking protocol. Overall, they praised the activities as engaging, even when challenging. However, a strong "instructor blindness" induced by remote teaching often prevented us from giving the students the right amount of guidance during the exploration activities

Abbiamo davvero bisogno del pensiero computazionale?

National audienceWe discuss if and to what extent we need the expression " computational thinking ". We argue that looking for a precise, operational definition could be misleading, and that this expression should not be used everywhere instead of " informatics ". " Computational thinking " , instead, is an instrumental expression which may help in suggesting that informatics is a new and distinct scientific discipline, and in motivating why it should be taught in the schools of any level.Esaminiamo in che misura sia necessaria l'espressione " pensiero computazionale " ed argomentiamo che può essere controproducente usarla in modo eccessivo insistendo a cercarne una definizione operativamente precisa. Questo termine dovrebbe servire, in modo strumentale, per spiegare sinteticamente perché l'informatica è una disciplina scientifica nuova e distinta dalle altre e perché dovrebbe essere insegnata a scuola a tutti i livelli

A necessity-driven ride on the abstraction rollercoaster of CS1 programming

International audienceIntroductory programming courses (CS1) are difficult for novices. Inspired by Problem solving followed by instruction and Productive Failure approaches, we define an original "necessity driven" learning design. Students are put in an apparently well-known situation, but this time they miss an essential ingredient (the target concept) to solve the problem. Then, struggling to solve it, they experience the necessity of that concept. A direct instruction phase follows. Finally, students return to the problem with the necessary knowledge to solve it. In a typical CS1 learning path, we recognise a challenging "rollercoaster of abstraction". We provide examples of learning sequences designed with our approach to support students when the abstraction changes (both upward and downward) inside the programming language, for example, when a new construct (and the related syntactical, conceptual, and strategic knowledge) is introduced. Also, we discuss the benefits of our design in light of Informatics education literature

Apprendimento della programmazione guidato dalla necessità: il Necessity Learning Design

Descriviamo una metodologia didattica originale, il Necessity Learning Design, in cui gli studenti cercano di risolvere un problema per il quale serve un concetto di programmazione che ancora non co- noscono, sentendone quindi la necessita`. Le fasi di spiegazione e di soluzione seguono. Descriviamo i primi risultati di una sperimentazione di questa metodologia in un istituto tecnico informatico

Analysing the potential of a simulation-based method for the assessment of CO2 savings from eco-innovative technologies in light-duty vehicles

[EN] Mandatory targets are set in Europe for Carbon Dioxide (CO2) emissions of light-duty vehicles. EU law recognises the potential of certain innovative technologies to contribute to reducing CO2 emissions. Vehicle systems and innovations are becoming increasingly complex, and the accurate quantification of their benefits increasingly difficult. The study investigates the potential of the CO2MPAS simulator to serve this purpose. Two innovative technologies were studied, Light-emitting diode (LED) lighting systems, efficient alternators (EA), and their combination. The model was validated on detailed test results from eight vehicles. A total of 452 passenger cars, for which test data were available, were subsequently simulated using CO2MPAS simulator. The mean simulated CO2 savings was 0.91gCO2/km (LED lights), 0.98 gCO2/km (EA), and 1.78 gCO2/km (combined). Results show that simulated CO2 savings were comparable to those calculated using the existing standardised method. For gasoline and diesel vehicles respectively, the difference in CO2 savings between simulated and existing method was 2.8% and 0.14% in the LED lights case, and 0.6% and 0.67% in the alternator case. In the combined case, the difference was calculated to be 1.7% and 0.34%. Similar approaches could be used in the future for accurately capturing the benefits of more complex technologies.Authors would like to thank Mr Filip Francois, Ms Susanna Lindvall, and Mr Sotirios Kakarantzas of DG Climate Action for their valuable comments. A special thanks goes to Dr Vincenzo Arcidiacono who guided in the targeted sample CO2MPAS simulations which gave the starting point for this work, and to Dr Giuseppe Di Pierro who provided insight and expertise that greatly improved this work.Gil-Sayas, S.; Komnos, D.; Lodi, C.; Currò, D.; Serra, S.; Broatch, A.; Fontaras, G. (2022). Analysing the potential of a simulation-based method for the assessment of CO2 savings from eco-innovative technologies in light-duty vehicles. Energy. 245:1-14. https://doi.org/10.1016/j.energy.2022.12323811424

Optimized Design and Multiphysics Analysis of a Ka-band Stacked Antenna for CubeSat Applications

Nowadays, the use of CubeSats for telecommunications and interplanetary missions is ever-increasing, thanks to their appealing low-cost character, as well as the space environment, which poses challenging multiphysics constraints on the antenna design. In this framework, the use of Ka-band for communication is explored. We present the design of a stacked patch antenna working across the down- and uplink Ka-bands. Materials and geometry of the radiator have been selected by accounting for the trade-off between electromagnetic, thermal and mechanical requirements. The design of the antenna is performed with a particle swarm optimization algorithm developed to control the bandwidth and matching. A bandwidth of [email protected] GHz has been obtained, with a gain around 8 dB. Furthermore, a multiphysics thermal analysis is performed to verify the operational stability of the optimized array, mounted on a 1 U satellite, in a case-study mission. The temperature patterns in the array are evaluated during the orbital period, and the influence of the operative temperature on the antenna responses and gain was considered. We found that the thermal loads can affect the antenna matching. However, thanks to the optimized design, the proposed stacked antenna can operate from −100 ∘ C to 100 ∘ C, with an almost constant gain. Finally, following a damage-tolerant approach, the level of mechanical deformation, which could be induced on the communication system, was studied. The stress analysis reveals that the stacked geometry can be used in a space mission. From the investigation of the strain and displacement field, we found a negligible impact on the antenna performance

Informatica senza e con computer nella Scuola Primaria

National audienceQuesto capitolo descrive le esperienze svolte da docenti e ricercatori del Dipartimento di Informatica - Scienza e Ingegneria (DISI) dell’Alma Mater Studiorum - Università di Bologna nell’ambito di alcuni progetti di disseminazione dei principi di base dell’Informatica (pensiero computazionale) nelle scuole primarie bolognesi.L’approccio che caratterizza i progetti presentati è l’utilizzo, sequenziale o intervallato, di attività sia “unplugged” sia “plugged”. Le prime - svolte senza l’utilizzo di un calcolatore, ma con materiali e oggetti di uso comune - sono state in parte tratte dal libro CS Unplugged, e in parte ideate dagli autori; le seconde hanno fatto uso del linguaggio visuale a blocchi Scratch.Con riferimento alla Proposta di Indicazioni Nazionali per l’Informatica nella Scuola [CINI17], tali attività hanno coperto soprattutto gli ambiti prettamente informatici di rappresentazione dell’informazione (es. numeri binari), algoritmi (es. massimo) e loro descrizione in uno pseudolinguaggio, programmazione; ma non hanno tralasciato quelli di creatività digitale (realizzare un progetto personale con Scratch) e consapevolezza digitale (es. regole di comportamento sulla community online di Scratch)