New Method for Measuring the Detail Preservation of Noise Removal Techniques in Digital Images

It is known that cancelling the noise without blurring the image details is a very difficult task for any image denoising technique. The availability of metrics for accurate evaluation of filtering distortion is thus of paramount importance for the development of new filters. Peak signal-to-blur ratio PSBR is a recently introduced measure of detail preservation that overcomes the limitations of the sole peak signal-to-noise ratio (PSNR) and other metrics in evaluating the performance of image denoising filters. Formally, the PSBR is the PSNR component that deals with the detail blur, so the method that is adopted for blur estimation plays a key role. This paper presents a novel algorithm for PSBR computation that offers significant advantages over the first method: it is simpler, more robust and much more accurate. Furthermore, this paper presents new validation tools for evaluating the accuracy of this kind of metrics when some well known classes of linear and nonlinear filters are considered. Results of many computer simulations dealing with images corrupted by different combinations of Gaussian and impulse noise show that the proposed PSBR algorithm outperforms the most effective metrics in the field

Piecewise Linear Model-Based Image Enhancement

A novel technique for the sharpening of noisy images is presented. The proposed enhancement system adopts a simple piecewise linear (PWL) function in order to sharpen the image edges and to reduce the noise. Such effects can easily be controlled by varying two parameters only. The noise sensitivity of the operator is further decreased by means of an additional filtering step, which resorts to a nonlinear model too. Results of computer simulations show that the proposed sharpening system is simple and effective. The application of the method to contrast enhancement of color images is also discussed

Shapley-PC: Constraint-based Causal Structure Learning with Shapley Values

Causal Structure Learning (CSL), amounting to extracting causal relations among the variables in a dataset, is widely perceived as an important step towards robust and transparent models. Constraint-based CSL leverages conditional independence tests to perform causal discovery. We propose Shapley-PC, a novel method to improve constraint-based CSL algorithms by using Shapley values over the possible conditioning sets to decide which variables are responsible for the observed conditional (in)dependences. We prove soundness and asymptotic consistency and demonstrate that it can outperform state-of-the-art constraint-based, search-based and functional causal model-based methods, according to standard metrics in CSL.Comment: 18 pages (with appendix

Cross-country analysis of science, technology and innovation policies: non-covid-19 related and Covid-19 specific STI policies in OECD countries

In OECD countries, Science, Technology and Innovation (STI) policies were seen as key aspects of coping with the Covid-19 pandemic. Now that the pandemic is over, identifying which policy mix portfolios characterised countries in terms of their non-Covid-19 related and Covid-19 specific STI policies fills a knowledge gap on changes in STI policies induced by exogenous shocks. The descriptive nature of this exercise sheds light on the emergency phase, which was addressed in different ways by countries with similar STI policy portfolios in the last decade before the pandemic. Using information on STI policy initiatives in OECD countries, this paper proposes a multidimensional analysis to classify policy initiatives based on both codes (of innovation policy themes, policy instruments and target beneficiaries) and free text policies’ descriptions. Based on text mining and clustering techniques, the multidimensional analysis highlights semantic similarities between the combinations of codes and terms, making it possible to identify policy mixes that characterise non-Covid-19 related and Covid-19 specific STI policies. The cross-country comparison draws attention to the specific policy mix portfolios implemented by countries during the pandemic. The paper contributes to the literature on innovation policy mix in terms of research methods and results in identifying STI policy portfolios and groups of countries with similar structural composition of their innovation policy portfolios, implementing a range of STI strategies in tackling the pandemic. Policy implications of the findings are discussed, with a forward-looking perspective for the analysis of post-pandemic STI policies

Docking Manoeuvre Control for CubeSats

Rendezvous and Docking missions of small satellites are opening new scenarios to accomplish unprecedented in-obit operations. These missions impose to win the new technical challenges that enable the possibility to successfully perform complex and safety-critical manoeuvres. The disturbance forces and torques due to the hostile space environment, the uncertainties introduced by the onboard technologies and the safety constraints and reliability requirements lead to select advanced control systems. The paper proposes a control strategy based on Model Predictive Control for trajectory control and Sliding Mode Control for attitude control of the chaser in last meters before the docking. The control performances are verified in a dedicated simulation environment in which a non-linear six Degrees of Freedom and coupled dynamics, uncertainties on sensors and actuators responses are included. A set of 300 Monte Carlo Simulation with this Non-Linear system are carried out, demonstrating the capabilities of the proposed control system to achieve the final docking point with the required accuracy

Quasi-static and low-velocity impact behavior of intraply hybrid flax/basalt composites

In an attempt to increase the low-velocity impact response of natural fiber composites, a new hybrid intraply woven fabric based on flax and basalt fibers has been used to manufacture laminates with both thermoplastic and thermoset matrices. The matrix type (epoxy or polypropylene (PP) with or without a maleated coupling agent) significantly affected the absorbed energy and the damage mechanisms. The absorbed energy at perforation for PP-based composites was 90% and 50% higher than that of epoxy and compatibilized PP composites, respectively. The hybrid fiber architecture counteracted the influence of low transverse strength of flax fibers on impact response, irrespective of the matrix type. In thermoplastic laminates, the matrix plasticization delayed the onset of major damage during impact and allowed a better balance of quasi-static properties, energy absorption, peak force, and perforation energy compared to epoxy-based composites

Programming PC-Based Multi-Function Oscilloscopes: A User-Friendly Approach to Rapid Prototyping of Spectral Analysis Code

Personal computer (PC)-based multi-function oscilloscopes are compact and low-cost programmable instruments that typically combine a multi-channel data acquisition unit, a signal generator and a USB interface to the PC. Although general purpose functions for spectral analysis based on the Fast Fourier Transform (FFT) are usually provided by the manufacturer in the accompanying software, the development of code for particular needs still remains a critical issue. This paper shows how new or more specific algorithms for frequency domain measurements can be easily implemented and tested for this class of instruments without spending time on a long and expensive training with dedicated development environments. The proposed approach is based on a recently introduced software shell, called DSPrototyper, where user interface and basic operations (for signal acquisition, processing and display) are already built-in and new measurement functions can be easily added by users having only a basic knowledge of programming languages. Some application examples are discussed in the paper focussing on the spectral analysis of a periodic signal and the implementation of algorithms that do not adopt the conventional time-domain windowing to reduce the spectral leakage

Learning online: Remote teaching and university student’s engagement

The COVID-19 pandemic has had a dramatic impact on many dimensions of living and working conditions, and uncertainties about the developments that we shall still face in the near future. This paper analyses the implications of a forced overnight push to online teaching. Drawing upon an online survey conducted during the 2020 lockdown by the University of Modena and Reggio Emilia, this article describes students' living and studying conditions revealed by a large set of open and closed questions. The survey provides significant information on the students' real off-campus conditions, crucial data for the multidimensional analysis by combining non-parametric multivariate analysis of closed questions with textual analyses. It offers important indications about the most useful tools for inclusive teaching across thematic areas and highlights the main difficulties that emerged during the lockdown. Reflections on advantages and disadvantages, strengths and weaknesses in the innovative learning environment set up overnight are offered at a policy level

First report outside Eastern Europe of West Nile virus lineage 2 related to the Volgograd 2007 strain, northeastern Italy, 2014

open11noWest Nile virus (WNV) is a Flavivirus transmitted to vertebrate hosts by mosquitoes, maintained in nature through an enzootic bird-mosquito cycle. In Europe the virus became of major public health and veterinary concern in the 1990s. In Italy, WNV re-emerged in 2008, ten years after the previous outbreak and is currently endemic in many areas of the country. In particular, the northeastern part of Italy experience continuous viral circulation, with human outbreaks caused by different genovariants of WNV lineage 1, Western-European and Mediterranean subcluster, and WNV lineage 2, Hungarian clade. Alongside the WNV National Surveillance Program that has been in place since 2002, regional surveillance plans were implemented after 2008 targeting mosquitoes, animals and humans.openRavagnan, Silvia; Montarsi, Fabrizio; Cazzin, Stefania; Porcellato, Elena; Russo, Francesca; Palei, Manlio; Monne, Isabella; Savini, Giovanni; Marangon, Stefano; Barzon, Luisa; Capelli, GioiaRavagnan, Silvia; Montarsi, Fabrizio; Cazzin, Stefania; Porcellato, Elena; Russo, Francesca; Palei, Manlio; Monne, Isabella; Savini, Giovanni; Marangon, Stefano; Barzon, Luisa; Capelli, Gioi