Archivio istituzionale della Ricerca - Università degli Studi di Parma
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Investigating Research Trends in Computer Vision for Food Quality Control: A Bibliometric Approach
No full textPWM Techniques for Two-Level Voltage Source Inverters: A Comparative Study
Get PDFPulse width modulation (PWM) techniques are widely used to control the switching of semiconductors in power converters. This paper presents a comprehensive overview of PWM techniques for two-level voltage source inverters and provides a comparative analysis of commonly employed PWM techniques, including sinusoidal PWM, zero-sequence injection PWM, third-harmonic injection PWM, space vector modulation, and optimized pulse pattern with selective harmonic mitigation. Besides providing a detailed literature review, this study includes multiple experimental results to evaluate the performance of these PWM techniques across different key metrics, such as output power quality, DC-link voltage utilization, dynamic response, and complexity. Given the growing trend of electrification in the transportation sector, particular emphasis is placed on motor drive applications. Furthermore, this paper discusses the impact of digital controllers, wide-bandgap semiconductors, and model predictive control on PWM techniques while addressing the challenges and future trends within this field
Is there a right to bear arms? Weapons regulation in Italy, the E.U., and the U.S.A. and its implications on global constitutional law
No full textThe possession and carrying of arms do not constitute a right in the Italian
legal system, but rather the exception to a general ban. This approach is further per-
petuated through criminal law sanctions, as confirmed by Constitutional Court case
law on the matter. Thus, firearms licensing operates with considerable limitations. Fur-
thermore, during the past thirty years, the European Union has adopted three direc-
tives in this field, gradually tightening requirements in this area. In doing so, the E.U.
recently triggered an action of annulment presented by three Member States before the
Court of Justice. In contrast, the opposite occurs in the U.S., as keeping and bearing
arms is a right the Supreme Court of the United States has held to be enshrined in the
Second Amendment of the Constitution. This right is understood as an individual one,
according to a seminal Supreme Court ruling. As illustrated by these wildly divergent
approaches, the right to bear arms fosters vibrant discussions on the meaning of law,
freedom, and community. Because of this, the purpose of this Paper is not only pro-
viding an overview of the existing norms on weapons and their interpretation, but also
highlighting the issues that they pose. Is there a right to possess arms? Or is it, instead,
a mere freedom? How feasible is it to mitigate the effects of the resulting negative ex-
ternalities? How far should lawmakers go? And, finally, what remains of national bor-
ders on the transnational stage in this area? In the ‘post-national constitution’ setting,
do geographic discrepancies in the protection of personal freedoms ultimately result
in their repudiation
Disassembly Time Analysis in U-shaped Snap-fit: an Experimental Approach
No full textSnap-fits are fasteners that join and separate components without screws, adhesives, or rivets, streamlining mechanical connection and disassembly in several applications, as electric appliances. This study focuses on evaluating manual disassembly time for U-shaped snap-fits, analyzing various geometric characteristics (tab width, length, inclination, and the number of locking tabs). The tests showed that slotted housings ease disassembly, with tab width and length having the most significant impact on time, while slope and lug count had minimal influence. The findings provide a basis for creating a database to support future design for disassembly tasks, improving circularity potential in many industrial sectors
Maximum List r-Colorable Induced Subgraphs in kP3-Free Graphs
No full textWe show that, for every fixed positive integers r and k, Max-Weight List r-Colorable Induced Subgraph admits a polynomial-time algorithm on kP3-free graphs. This problem is a common generalization of Max-Weight Independent Set, Odd Cycle Transversal and List r-Coloring, among others. Our result has several consequences. First, it implies that, for every fixed r ≥ 5, assuming P ≠ NP, Max-Weight List r-Colorable Induced Subgraph is polynomial-time solvable on H-free graphs if and only if H is an induced subgraph of either kP3 or P5 + kP1, for some k ≥ 1. Second, it makes considerable progress toward a complexity dichotomy for Odd Cycle Transversal on H-free graphs, allowing to answer a question of Agrawal, Lima, Lokshtanov, Rzążewski, Saurabh, and Sharma [ACM Trans. Algorithms 2025]. Third, it gives a short and self-contained proof of the known result of Chudnovsky, Hajebi, and Spirkl [Combinatorica 2024] that List r-Coloring on kP3-free graphs is polynomial-time solvable for every fixed r and k. We also consider two natural distance-d generalizations of Max-Weight Independent Set and List r-Coloring and provide polynomial-time algorithms on kP3-free graphs for every fixed integers r, k, and d ≥ 6
Modeling the relationships among technological properties of sheep individual animal factors, milk composition, and minerals using generalized additive mixed models
No full textThe dairy sheep industry faces ongoing challenges in optimizing cheese production and enhancing efficiency across different breeds. This study provides crucial insights into how breed-specific factors, lactation stages, parity, and milk composition, including mineral concentrations, affect cheese yield and nutrient recovery in the curd. The aims of this study were to characterize individual sheep milk samples for cheesemaking efficiency by measuring 3 cheese yield traits (%CY; fresh curd, TS, and water retained) and 5 nutrient recovery traits (%REC; fat, protein, lactose, TS, and energy) and to examine how these traits change throughout the lactation, considering different sheep breeds, parities, and variations in milk composition and mineral concentrations. A total of 760 ewes from Massese and Comisana breeds were sampled during the morning milking at the National Association of Sheep Breeders nucleus farm (Tuscany, Italy). The application of generalized additive mixed models (GAMM) was a key element of this study, enabling a more nuanced analysis of complex relationships and nonlinear trends. The GAMM accounted for variations in breed and parity, which were included as parametric terms, as well as milk minerals, rennet coagulation time (RCT), sampling day, and interactions between DIM and milk yield (MY), fat and casein, and Ca and P, which were treated as smooth terms. This approach provided insights that would have been difficult to capture with traditional linear models. Results evidenced breed and parity-specific variations. Indeed, the Massese had overall lower cheesemaking efficiency compared with the Comisana ewes, and primiparous ewes had higher percentages of both %CY and %REC traits. The interaction between DIM × MY was less significant in the Comisana breed compared with the Massese, with notable effects only on protein and lactose recovery in the Comisana. The interaction between fat × casein was also breed specific and affected with different extent and patterns the cheesemaking traits between the 2 breeds. Longer RCT increased the water retained in the curd and reduced the recovery of TS and the individual recovery rates of the main milk components in both breeds. The effect of Ca × P was not always linear on the cheesemaking traits and between breeds. Overall, an increase of both Ca and P was associated with higher %CY and %REC, except for the recovery of fat and energy. High Na and Cl were detrimental for the cheesemaking process in both breeds, whereas the destabilizing effect of K was particularly notable on the fresh curd, curd TS and the recovery of protein from the Massese milk. These findings highlight that sheep breed and parity, alongside specific milk components and mineral concentrations, significantly affect cheesemaking efficiency, with important differences between the Massese and Comisana breeds. Efficient cheesemaking requires careful consideration of mineral concentrations, especially in terms of Ca, P, Na, Cl, and K, to optimize yields and nutrient recovery in the curd
Computational Perspectives on Amoxicillin and Staphylococcus Aureus in Mirror Life
No full textThe concept of mirror life is first introduced by Louis Pasteur, referring to biological systems composed of enantiomeric biomolecules. Although nowadays technologies are making a mirror life theoretically achievable, its potential risks remain uncertain. Here, an integrated multi-tier computational pipeline is employed to address the potential environmental threat posed by the hypothetical mirror-image of Staphylococcus aureus, a bacterium relevant to environmental and food safety. The findings suggest that amoxicillin, and perhaps other conventional antibiotics, should not be effective against their mirror targets. On the other hand, the enantiomeric amoxicillin may be a successful counteracting measure, although the risks for the biosphere remain unknown. Overall, this study highlights the need for further dedicated investigations in this field, while emphasizing in silico methods, in particular molecular modeling, as a versatile and effective first-line approach for analysis, free from biohazards and technical limitations of reagents supply
Insights in Interactions Reshaping Caused by the HFE Protein C282Y Mutation in Hereditary Hemochromatosis
No full textHFE protein is a class I major histocompatibility complex (MHC) homolog, formed by two domains: the 1,2 MHC-like domain and the 3 immunoglobulin-like domain. WT HFE competes with iron-loaded transferrin (Tf) for binding to the transferrin receptor (TfR) at the cell surface and, interfering with Tf binding site on TfR, regulates iron absorption. The mutated protein is not able to bind TfR and the regulation fails, causing an iron overload, a characteristic of Hereditary Hemochromatosis (HH) desease. The predominant mutation in HH is the C282Y (C260Y in the mature protein) in the 3 domain, which converts a cysteine residue in a tyrosine, breaking a disulphide bond and affecting the association of HFE with a 2-microglobulin (2m) chain, therefore preventing its externalization at the cell surface. Several hypothesis were made about this failing. By means of molecular dynamics simulations, we try to go into detail of structural changes occurring in the 3 domain due to the mutation, which alter the electrostatic features of protein surfaces affecting the interaction with the 2m chain and with the 1,2 domain of HFE itself. PCA analysis allowed to observe a reciprocal rotation of the three domains, which leads to the loss of several conserved contacts, but substantially maintains the overall fold of each of them