Nonlinear Adaptive Biasing for Low-Voltage Class-AB OTAs

An adaptive biasing circuit suitable for very low-voltage design of class-AB symmetrical ransconductance operational amplifiers (OTAs) is presented. A non-linear current mirror is exploited to enhance the maximum tail current as a function of the input voltage, achieving a super class-AB behavior. Robustness to process and voltage supply variations and advantages of the proposed solution are demonstrated by designing a 0.6Vclass-ABOTAwith adaptive biasing in 0.13-μm CMOS technology, and evaluating its performance in unitygain buffer configuration. The use of the proposed adaptive bias circuit provides a 20x slew-rate improvement with respect to the same OTA biased at constant current

Predictive Analytics for Road Traffic Accidents: Exploring Severity through Conformal Prediction

Road traffic accidents are a significant global health concern with far-reaching economic consequences. In an innovative bid to address this issue, our study predicts accident severity in Rome, leveraging a comprehensive dataset from 2006 to 2022, a first in the literature. We analyzed multiple factors, including weather conditions, road and vehicle conditions, types of accidents, and time-related aspects. Distinguishing our study, we applied one-hot encoding to categorical variables, demonstrating superior model performance over traditional label encoding. Additionally, we employed the Synthetic Minority Over-sampling Technique (SMOTE) to handle data imbalance and provided a detailed analysis of its impacts on model performance. Our key innovation lies in implementing conformal prediction to quantify prediction uncertainty. Given the prevalent skewness in traffic accident datasets, this technique enhances decisionmaking reliability and precision. We deployed a series of machine learning models, with the Extreme Gradient Boost (XGBoost) algorithm outperforming others in predicting injury severity, boasting a remarkable 77% accuracy rate. Implementing SHapley Additive exPlanations (SHAP) ensured model interpretability, underscoring the type of vehicles involved, the nature of the accident, and road shape as the most influential factors. In conclusion, our approach combining XGBoost, one-hot encoding, SMOTE, and conformal prediction provides a comprehensive, efficient, and transparent method for predicting road accident severity. Incorporating conformal prediction offers critical insights into model uncertainty, significantly aiding decision-making in road traffic safety. Additionally, SHAP analysis highlights the key factors contributing to accident severity, guiding focused preventive strategies

Hegel, the End of History and the Crisis of European Primacy

This paper critically dissects Hegel’s Eurocentric philosophy of history, scrutinizing biases in his portrayal of Europe as the zenith of historical and spiritual development. Using Biagio De Giovanni’s insights as a departure point, the analysis delves into Hegel’s racial hierarchy, unraveling contradictions in his depiction of Asia, Africa, and America. Emphasizing the dialectical method inherent in Hegel’s Eurocentrism, the paper reveals Europe as a paradox— both the pinnacle of freedom and reason and a region laden with unresolved complexities. Examining Hegel’s philosophy in a contemporary context, particularly amidst Europe’s ongoing crisis and the ascendancy of alternative narratives like China, the paper challenges Eurocentric claims across economic, political, and ecological domains. In conclusion, the paper posits that Hegel’s philosophy, while rooted in Eurocentrism, prompts self-reflection and challenges the notion of a definitive end to history. Ongoing European crises and shifting global dynamics necessitate a nuanced reassessment, acknowledging the potential emergence of new world narratives beyond conventional Western perspectives

Explainable spatio-temporal Graph Neural Networks for multi-site photovoltaic energy production

In recent years, there has been a growing demand for renewable energy sources, which are inherently associated with a decentralized distribution and dependent on weather conditions. Their management and associated forecasting of produced energy are tasks of increasing complexity. Spatio-Temporal Graph Neural Networks have been applied in this context with excellent results, taking advantage of the correct integration of both topological data, defined by the distribution of the plants in the territory, and temporal data of the time series. A drawback of graph neural networks is the recurrent mechanism adopted to process the temporal part, which increases greatly the computational load of these models. Moreover, these models are formulated for real and sensitive contexts where, in addition to being accurate, the predictions must also be understandable by the human operator. For these reasons, in this paper we propose a novel explainable energy forecasting framework based on Spatio-Temporal Graph Neural Networks: the forecasting model generates predictions by processing temporal and spatial information using a spectral graph convolution and a 1D convolutional neural network respectively, then we apply a state-of-the-art explainer to them in order to produce explanations about the generation process. Our proposed method obtains predictions having better performance than previous approaches, both in terms of computational efficiency and prediction accuracy, with the possibility of interpreting them in order to understand the generation process. The novel approach based on fusion of forecasting and explainability in a single framework enables the creation of powerful and reliable systems suitable for real-world issues and challenges

Prospettive per una città di prossimità nell’era post-pandemica

Con l’avvento della pandemia da Covid-19 i rapporti tra uomo e comunità sono stati stravolti generando dibattiti sul ripensamento delle città e degli spazi domestici. Dall’evidenza degli errori compiuti finora e dalle nuove evidenze emerse, quali virtualità sociale e sostenibilità ambientale, si illustrerà il valore della “città di prossimità”, che coniuga la dimensione urbana e abitativa alle necessità sociali e relazionali del singolo e della comunità cittadina.With the advent of the Covid-19 pandemic, relations between man and community have been distorted, generating debates on the rethinking of cities and domestic spaces. From the evidence of the errors to date and from the new realities that have emerged, such as social virtuality and sustainability, the value of the “city of proximity” will be illustrated, which combines the urban and housing dimension with the social and relational needs of the individual and community of the city

Sustainability: A Behavioral Perspective

Human behavior plays a significant role in the deterioration of the environment, contributing to issues such as climate change and biodiversity loss. To address these challenges, it is crucial to comprehend the factors that influence individual choices concerning re-source consumption, waste disposal, sustainable transportation, and environmental advocacy. Sustainable behaviors often come with economic, effort, and time costs, so understanding the motivations and incentives that drive individuals' decisions is necessary. The Behavior-Based Design approach emerges as a promising framework for modifying behaviors to benefit individuals, society, and the environment. By targeting behavior change, this approach seeks to promote sustainable practices and mitigate the negative impacts caused by human activities. In line with this, researchers should adopt a structured methodological approach to behavior change within sustainable living. This entails developing interventions to encourage sustainable behaviors and evaluating their long-term effectiveness. By implementing systematic and rigorous evaluation methods, researchers can gain valuable insights into the strategies and techniques that prove most successful in promoting sustainable behaviors over extended periods. Such an approach will provide a deeper understanding of behavior change dynamics and help inform the design of effective interventions to foster sustainable practices

Gli Stati Uniti e il loro diritto

Una storia giuridico politico economica degli Stati Uniti dalle colonie alla presidenza Biden

Gender and gambling preference

Gambling preferences are analysed using survey data from the wider population. Respondents were confronted with a hypothetical lottery question, in which they were asked to imagine having just won a large prize, and asked how much of this prize they would be willing to invest in a further gamble. We observe the majority of respondents avoiding the gamble altogether. We demonstrate that such behaviour cannot easily be explained by standard models of choice under risk, since it implies implausible degrees of risk aversion. We propose that the observed behaviour can instead be explained in terms of gambling aversion. Since the decision variable takes the form of the number of ‘units’ of the prize that the respondent wishes to invest in the gamble, and since the decision is observed twice for some respondents, we adopt the panel version of the Zero-Inflated Poisson model as an econometric framework. We assume that individual characteristics affect both stages of the decision-making process. We are particularly interested in the effect of gender, and we find that males have a significantly higher probability of participating in the gamble, and are also (conditional on gambling) prepared to gamble significantly larger amounts

Ecological strategies of bacterial communities in prehistoric stone wall paintings across weathering gradients. A case study from the Borana zone in southern Ethiopia

Rock art paintings represent fragile ecosystems supporting complex microbial communities tuned to the lithic substrate and climatic conditions. The composition and activity of these microbial communities associated with different weathering patterns affecting rock art sites remain unexplored. This study aimed to explore how bacterial communities adapt their ecological strategies based on substrate weathering, while also examining the role of their metabolic pathways in either biodeterioration or bioprotection of the underlying stone. SEM-EDS investigations coupled with 16S rRNA gene sequencing and PICRUSt2 analysis were applied on different weathered surfaces that affect southern Ethiopian rock paintings to investigate the relationships between the current stone microbiome and weathering patterns. The findings revealed that samples experiencing low and high weathering reached a climax stage characterized by stable microenvironments and limited resources. This condition favored K-strategist microorganisms, leading to reduced α-biodiversity and a community with a positive or neutral impact on the substrate. In contrast, moderately-weathered samples displayed diverse microhabitats, resulting in the prevalence of r-strategist bacteria, increased α-biodiversity, and the presence of specialist microorganisms. Moreover, the bacterial communities in moderately-weathered samples demonstrated the highest potential for carbon fixation, stress responses, and complete nitrogen and sulfur cycles. This bacterial community also showed the potential to negatively impact the underlying substrate. This research provided valuable insights into the little-understood ecology of bacterial communities inhabiting deteriorated surfaces, shedding light on the potential role of these microorganisms in the sustainable conservation of rock art

Proposta progettuale di allestimento e conservazione del blocco centrale sud delle 'Case Giardino' presso il Parco Archeologico di Ostia Antica in Roma

L'Oggetto di studio è il blocco centrale sud delle Case Giardino presso il Parco Archeologico di Ostia Antica. Lo studio ha compreso: l'analisi storica del sito e delle sue fasi costruttive, il rilievo diretto del degrado, l'elaborazione del progetto di restauro delle strutture e delle superfici, il progetto di allestimento museale e illuminazione e di nuove coperture protettive per la conservazione soprattutto degli affreschi e mosaici. Nell’oggetto analizzato la lacuna intesa come interruzione, spazio vuoto creato dalla mancanza di ciò che dovrebbe occuparlo, si incontra in varie componenti dell’architettura: nelle pavimentazioni in mosaico, negli strati pittorici degli affreschi, nelle strutture murarie intese sia come singoli elementi che come interi elementi compositivi (es. pareti e coperture); essa rappresenta una interruzione del tessuto figurativo di cui elementi sono: atmosfera, luce, presentazione, condizioni fisiche e termo-igrometriche, che incide sulla leggibilità del singolo elemento e nell’insieme, dell’intera struttura architettonica e da essa all’ambiente circostante (ricaduta a più livelli), ma oltre all’aspetto figurativo (alterazione del valore espressivo dell’opera e della sua capacità comunicative) essa essendo una perdita fisica di materia può rappresentare un pericolo per la conservazione delle strutture e delle superfici straformandosi, la dove non risolta, in veicolo di degrado. La lacuna in relazione alla sua causa generatrice può assumere valore di testimonianza storica, un segno sulla materia che ci racconta gli accadimenti che la struttura ha subìto, rivelandoci spesso i diversi usi succedutisi nel tempo che l’hanno caratterizzata la cui integrazione ne comprometterebbe la lettura. Quindi nel caso preso in esame le lacune sono state valutate caso per caso analizzandone le cause e gli effetti, prevendendo l’integrazione solo li dove vi sono state riconosciute necessità di conservazione e ripristino della leggibilità figurativa. Per l’analisi del degrado e il relativo intervento di restauro è stato preso come un singolo ambiente rilevato internamente ed esternamente come esempio pilota delle patologie osservate e le relative soluzioni da applicare all’intera costruzione che presenta una superficie molto estesa, indicandone le tecniche e i materiali scelti, lo studio ha riguardato strutture murarie, pavimenti in mosaico e affreschi parietali. La necessità di preservare le strutture archeologiche portate alla luce e la scelta irrinunciabile della conservazione in sito nel contesto originario, di manufatti come rivestimenti parietali e pavimentali spesso molto fragili; l’opportunità di esporre alla fruizione pubblica stratigrafie e delicati manufatti pone il problema della loro protezione, favorendo la ricerca di soluzioni differenziate tra cui la realizzazione di coperture. Il progetto presentato propone un sistema di allestimento e copertura discreto, volto a restituire un immagine organica, significativa e parlante delle qualità materico-costruttive e decorative del reperto e della spazialità del suo impianto architettonico, suggerendo le funzioni originali, il tipo di vita e i rapporti dell’insediamento con il contesto territoriale che lo comprende, pone al centro dell’attenzione il rudere, presentando con chiarezza il carattere e la qualità spaziale della struttura antica favorendone la leggibilità. Grande attenzione viene posta al rapporto tra la testimonianza antica e la struttura moderna che inevitabilmente partecipa alla sua immagine, entrando in rapporto sia nelle sue relazioni spaziali interne sia con il paesaggio circostante. Una sistema di copertura improntato sulla leggerezza visiva e strutturale che non grava sulla preesistenza, con montaggio interamente a secco di facile smontaggio e manutenzione, flessibile e modificabile che può essere applicato ad altre strutture archeologiche del parco che presentano le stesse problematiche di conservazione