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Distance properties of punctured simplex codes and design of high-rate PRC-LDPC codes for complexity-constrained applications
No full textCyclic simplex codes are usually deemed as impractical because of their extremely low rate and large codeword length for practical values of the code dimension. To address these limitations, researchers have resorted to punctured simplex codes, focusing on primitive polynomials and employing statistical analyses to investigate their properties. This paper delves deeper into the properties of punctured binary simplex codes, also focusing on the recently introduced family of Primitive Rate-Compatible Low-Density Parity-Check (PRC-LDPC) codes. We study the average behavior of punctured simplex codes in terms of minimum distance properties. Furthermore, our results highlight the potential of high-rate PRC-LDPC codes to reach or even surpass the performance of state-of-the-art code families. We show how to design good codes by applying puncturing and shortening operations to cyclic simplex codes, also considering complexity-constrained scenarios
Development of a Cluster Analysis Framework for quality control by Resonance Testing in Additive Manufacturing
No full textLa produzione additiva di componenti metallici consente la realizzazione di geometrie complesse, ma risente della variabilità intrinseca del processo, che spesso si traduce in proprietà meccaniche inconsistenti. Sebbene la tomografia computerizzata a raggi X rappresenti il "gold standard" per il rilevamento dei difetti, i suoi costi elevati e i tempi di ciclo lenti ne limitano l'impiego per il monitoraggio del 100% della produzione. I sistemi di ispezione Resonance Testing offrono un'alternativa rapida e scalabile; tuttavia, le attuali soluzioni commerciali si basano tipicamente su algoritmi di machine learning, richiedendo costosi dataset di addestramento con classi assegnate. Questa tesi presenta lo sviluppo di un nuovo framework di clustering non supervisionato per Resonance Testing, volto ad automatizzare il controllo qualità senza una conoscenza preventiva sul tipo di difettositá. La ricerca introduce un framework software modulare che comprende un algoritmo per il posizionamento automatico della finestra di rilevamento e un modulo di elaborazione del segnale progettato per compensare la variabilità sistematica intrinseca alla piastra di stampa del processo Laser Bed Powder Fusion. Questo modulo identifica e rimuove la variabilità sistematica relativa al layout della piastra di stampa, migliorando così la sensibilità del sistema di ispezione verso gli effettivi componenti difettosi. Inoltre, è stata sviluppata una metrica di compatibilità dei lotti per quantificare la coerenza della produzione tra diversi cicli di fabbricazione. Il framework impiega modelli di clustering di consenso, nello specifico DBSCAN e Gaussian Mixture, abbinati a strategie ottimizzate di feature linkage. La validazione sperimentale è stata condotta su componenti in Ti-6Al-4V utilizzando sia l'Acoustic Resonance Testing che il Vibration-based Resonance Testing ad alta larghezza di banda. I risultati dimostrano che specifiche configurazioni del framework non supervisionato raggiungono un tasso di falsi negativi inferiore rispetto ai software commerciali allo stato dell'arte, sebbene il tasso di falsi positivi richieda un'ulteriore ottimizzazione. Inoltre, un'analisi di separabilità dei parametri modali ha confermato che le frequenze naturali rimangono le caratteristiche più robuste per il rilevamento dei difetti rispetto ai rapporti di smorzamento o alle forme modali, in particolare quando l'orientamento del componente non è controllato. In conclusione, sebbene l'approccio di clustering non supervisionato riduca la dipendenza dai dati etichettati, si raccomanda la transizione verso un modello di regressione physics-informed per garantire la stabilità necessaria all'impiego industriale.Metal Additive Manufacturing enables the production of complex geometries but suffers from inherent process variability, often resulting in inconsistent mechanical properties. While X-ray Computed Tomography is the gold standard for defect detection, its high cost and slow cycle times limit its use for 100% production monitoring. Resonance Testing offers a scalable, rapid alternative; however, current commercial solutions typically rely on supervised learning, necessitating expensive, pre-labelled training datasets. This thesis presents the development of a novel unsupervised clustering framework for RT to automate quality control without prior knowledge of defect classes. The research introduces a modular software framework featuring an algorithm for automatic detection window positioning and a signal processing module designed to compensate the systematic variability inherent in the Laser Bed Powder Fusion process. This module identifies and removes systematic variability related to the build plate layout, thereby enhancing the inspection system sensitivity to actual defective parts. Additionally, a batch compatibility metric was developed to quantify production consistency across different manufacturing runs. The framework employs consensus clustering models, specifically DBSCAN and Gaussian Mixture, coupled with optimized feature linkage strategies. Experimental validation was conducted on Ti-6Al-4V components using both Acoustic Resonance Testing and high-bandwidth Vibration-based Resonance Testing. Results demonstrate that specific unsupervised framework configurations achieve a lower Missing Alarms Rate compared to commercial state-of-the-art software, although False Positive Rates require further optimization. Furthermore, a separability analysis of modal parameters confirmed that natural frequencies remain the most robust features for defect detection compared to damping ratios or mode shapes, particularly when component orientation is uncontrolled. In conclusion while the unsupervised clustering approach reduces the reliance on labelled data, transitioning to a physics-informed regression model is recommended to ensure the stability required for industrial deployment
Al-driven cement functionality by manifold structuring & disorder
No full textCementitious calcium–silicate–hydrate (C–S–H) gel structures with differing aluminium (Al) content and structuring were characterised by a series of ab initio molecular dynamics (AIMD) experiments. Differing Al-binding modes and coordinations (4, 5, 6) were incorporated into dynamic simulations of various C–S–H bulk structures (layered, non-layered, anhydrous porous, hydrated porous) to resolve Al's configurational preference as well as any effects on Si/Al chain structure, including Lowenstein type ‘Al-avoidance’ (preference for non-neighbouring Al atoms) and Pore sizes. Emphasis was placed on modelling fault lines in C–(A–)S–H structures, where local order is thought to be lost. These regions tend to have high concentrations of micro stresses that potentially induce crack propagation and would thus possibly benefit from Al-toughening. Principal aspects of Loewenstein's Al avoidance are not operative in the majority of cases, with alternating Al atoms increasing chain length and branching giving rise to larger pores. O–Al–O and Al–O–Al bond angles were shown to be more flexible than their Si counterparts (O–Si–O, Si–O–Si), the former Al-units effectively acting as atomic hinge points. Al-coordination was shown to shift dynamically throughout each simulation, generally occupying tetrahedral Al-IV geometry with some preference for penta-coordinated Al-V at Q2 and Q3 sites. Loewenstein's principle of opposite coordination modes for adjacent Al are observed; specifically, Al neighbours will seldom hold the same coordination geometry. Through this approach we have demonstrated structuring of C–(A–)S–H containing stable hydrated pores, in agreement with experimental trends arising from empirical NMR and small angle neutron scattering (SANS) measurements in established works
Garlic and breast cancer: how far has the research come?
No full textBreast cancer is the most diagnosed female tumor in the world, and its management and treatment are important challenges for clinicians. Many risk factors are associated with the onset and progression of this disease, and, among these, a balanced and healthy diet plays a crucial role. In recent years, the attention of the scientific community has been focused on the health effects of dietary bioactive compounds, with well-known antioxidant and anti-inflammatory activities, as an important tool to prevent many common human diseases, including cancer. In this context, garlic, a widely cultivated and consumed spice, is a rich source of natural compounds, mainly organosulfur compounds, phenolics, saponins, and polysaccharides, whose biological activities are closely associated with its beneficial effects on human health. This perspective study aims to present published data on the effects of garlic in breast cancer, highlighting the molecular mechanisms involved and suggesting the research prospects
Managerial Training and Business Transformation in Italian Manufacturing Firms. The Role of the National Recovery and Resilience Plan
No full textThis paper explores the role of the National Recovery and Resilience Plan (NRRP) as a driver for the reconfiguration of companies’ business profile in the Italian economy. Using a unique database containing information on 1779 Italian manufacturing firms, we find that the NRRP has stimulated a significant reconfiguration of their business profile. Interestingly, companies that invest in managerial training are more likely to fully leverage the opportunities created by the NRRP. In contrast, no effect is found for firms investing in general training or those with a high proportion of white-collar workers. These findings highlight the importance of managerial capabilities in enabling firms to navigate transformations and reshape their business profile accordingly
Digital Literacy, Digital Readiness and Acceptability of Digital Mental Health Among Mental Health Professionals: Findings from the Italian DIGIT-PSY Study
No full textThe Co-Optation of Gender Equity Issues in Empirical Business Research: A Systematic Literature Review
No full textThe aim of this study is to develop a conceptual framework for examining how gender equity issues are co-opted within CSR activities, focusing on empirical, business-related studies. The authors investigate how companies navigate the co-optation of gender equity, its subphenomena, underlying conditions, and employed strategies. A systematic literature review was conducted, followed by a thematic analysis due to the limited research available on this subject. The findings reveal that companies often engage in “CSR-washing” practices, specifically fem-washing, gender-washing, pink-washing, or rainbow-washing, depending on the target audience and strategic objectives. These practices typically involve superficial actions or messaging that fail to address structural inequalities, using gender equity themes primarily for reputation management or profit-driven motives. While this study provides valuable insights, it is limited by its reliance on the Scopus database, which excludes nonindexed sources. Additionally, the subjective nature of thematic analysis may result in varying interpretations by different researchers. Despite these limitations, this study makes a significant contribution to gender-related CSR research. It offers a systematic overview of the conceptual boundaries, practical manifestations, and contributing factors involved in the co-optation of gender equity issues. This framework lays a strong foundation for future research, particularly quantitative studies and critical analyses of CSR-washing strategies. Additionally, it underscores the importance of structural reforms to ensure authentic gendered CSR practices and highlights the need for stronger regulatory frameworks and standardized reporting to enhance transparency and accountability
Sepsis-induced coagulopathy is associated with impaired tissue oxygen extraction and microvascular reactivity: a prospective observational study
No full textBackground: Coagulopathy is a key driver of organ dysfunction during sepsis/septic shock, yet its relationship with microcirculatory autoregulation is not fully characterized. This study aimed to evaluate the association between sepsis-induced coagulopathy (SIC) and alterations in tissue oxygenation, oxygen extraction capacity and microvascular reactivity. Methods: Prospective observational study on 23 adult septic patients. Coagulation status was evaluated with standard laboratory parameters and thromboelastography (TEG). A SIC score ≥ 4 was used to identify the presence of coagulopathy. The peripheral (skeletal muscle) tissue oxygen saturation (StO2) was assessed using thenar near infrared spectroscopy (NIRS). By combining a vascular occlusion test, the desaturation rate during ischemia was assessed as an index of oxygen extraction capacity: this was measured separately for the first (StO2 downslope-1) and last part (StO2 downslope-2) of the desaturation curve, and the difference between the two was calculated (delta-downslope). The reoxygenation rate (StO2 upslope) and the area of the hyperemic phase were calculated to evaluate microvascular reactivity. Results: In patients with SIC, the delta-downslope was higher (1.7 ± 2.5 versus −0.8 ± 3.2, p = 0.049) and the StO2 upslope was reduced (96 ± 74 versus 185 ± 91, p = 0.017), suggesting altered tissue oxygen extraction capacity and microvascular reactivity. Both parameters were able to discriminate the presence of SIC in the receiver operating characteristics curve analysis. Negative correlations were found between StO2 downslope-1 and TEG maximum amplitude (r = −0.470, p = 0.023), and Delta-Downslope and platelet count (r = −0.527, p = 0.01). Conclusions: SIC is associated with alterations in peripheral tissue oxygen extraction capacity and microvascular reactivity
Loneliness, Aloneness, and Adherence to the Mediterranean Diet in Southern Italian Individuals
No full textBackground/Objectives: Research across multiple disciplines has explored how nutrition is shaped by social isolation and feelings of loneliness, especially in the elderly population. Evidence from neuroscience highlights that loneliness may alter eating patterns, encouraging emotional eating or other compensatory food behaviors. Conversely, isolation from social contexts is often linked to a reduced variety of nutrient intake. This study set out to examine how psychosocial aspects, particularly social connectedness and feeling alone, relate to adherence to the Mediterranean diet among older adults residing in Sicily, southern Italy. Methods: Dietary habits of 883 adults were collected through food frequency questionnaires and assessed for adherence to the Mediterranean diet. Loneliness was measured through a targeted question from a standardized tool designed to capture depressive symptoms. Direct questions asked whether participants were engaged in social networks, such as family, friends and neighborhoods, or religious communities, in order to assess objective aloneness. Logistic regression analyses were performed to assess associations between variables of interest. Results: After accounting for potential confounders, both loneliness and aloneness showed an association with stronger adherence to the Mediterranean diet. Specifically, individuals experiencing loneliness and aloneness were less likely to have high adherence to the Mediterranean diet (OR = 0.28, 95% CI: 0.15, 0.51, and OR = 0.26, 95% CI: 0.12, 0.54, respectively). Conclusions: These findings underscore the importance of fostering social engagement among older populations, who may particularly benefit from maintaining active social ties to support healthier eating behaviors