Multivariate Nonparametric Estimation of the Pickands Dependence Function using Bernstein Polynomials

Many applications in risk analysis, especially in environmental sciences, require the estimation of the dependence among multivariate maxima. A way to do this is by inferring the Pickands dependence function of the underlying extreme-value copula. A nonparametric estimator is constructed as the sample equivalent of a multivariate extension of the madogram. Shape constraints on the family of Pickands dependence functions are taken into account by means of a representation in terms of a specific type of Bernstein polynomials. The large-sample theory of the estimator is developed and its finite-sample performance is evaluated with a simulation study. The approach is illustrated by analyzing clusters consisting of seven weather stations that have recorded weekly maxima of hourly rainfall in France from 1993 to 2011

Chemical evolution of the bulge of M31: predictions about abundance ratios

We aim at reproducing the chemical evolution of the bulge of M31 by means of a detailed chemical evolution model, including radial gas flows coming from the disk. We study the impact of the initial mass function, the star formation rate and the time scale for bulge formation on the metallicity distribution function of stars. We compute several models of chemical evolution using the metallicity distribution of dwarf stars as an observational constraint for the bulge of M31. Then, by means of the model which best reproduces the metallicity distribution function, we predict the [X/Fe] vs. [Fe/H] relations for several chemical elements (O, Mg, Si, Ca, C, N). Our best model for the bulge of M31 is obtained by means of a robust statistical method and assumes a Salpeter initial mass function, a Schmidt-Kennicutt law for star formation with an exponent k=1.5, an efficiency of star formation of $\sim 15\pm 0.27\, Gyr^{-1}$, and an infall timescale of $\sim 0.10\pm 0.03$Gyr. Our results suggest that the bulge of M31 formed very quickly by means of an intense star formation rate and an initial mass function flatter than in the solar vicinity but similar to that inferred for the Milky Way bulge. The [$\alpha$/Fe] ratios in the stars of the bulge of M31 should be high for most of the [Fe/H] range, as is observed in the Milky Way bulge. These predictions await future data to be proven.Comment: Accepted for publication by MNRA

PageRank vs. ANP: A Comparative Analysis for Prioritizing Maintenance Activities in Industrial Water Distribution Systems.

This paper proposes the implementation of the PageRank algorithm as an alternative to the Analytic Network Process (ANP) for prioritizing maintenance activities in water distribution systems. We demonstrate the comparable performance of the PageRank algorithm to the ANP by comparing the results obtained from a previous conference paper that utilized the ANP for decision-making in sustainability-related problems involving water distribution systems feeding manufacturing industries. The ANP is commonly used for decision-making in complex systems, but has limitations such as subjective weighting and handling large datasets. In contrast, the PageRank algorithm, originally designed for web page ranking, offers a scalable and objective approach for analyzing complex systems. To showcase the effectiveness of the PageRank algorithm, we compare the results obtained from the ANP in our previous conference paper with the PageRank algorithm. Our findings reveal that the PageRank algorithm yields identical results to the ANP, while addressing its limitations. The results of this study demonstrate the viability and effectiveness of the PageRank algorithm in achieving identical outcomes as the ANP, with potential advantages in scalability and objectivity. The proposed implementation of the PageRank algorithm as an alternative to the ANP offers a promising approach for prioritizing maintenance activities in water distribution systems, as similar considerations can be extended to any sector of activity

How sustainability factors influence maintenance of water distribution systems feeding manufacturing industries

This work aims to analyse the role played by relevant sustainability factors towards the implementation of maintenance interventions in the manufacturing industrial sector. In this context, we focus on industrial water distribution systems, on whose effective work depends the functioning of core plants as well as general industrial facilities. In detail, we propose aMulti-Criteria Decision-Making (MCDM) application based on the use of the Analytic Network Process (ANP) as amethodological way to prioritise maintenance interventions while considering the influence of some of themost relevant sustainability factors identified in literature. The main advantage of such an approach consists in the elaboration of a flexible maintenance procedure for companies based on a well-known and reliablemulti-criteria application. The novelty of our work refers to the development of a structured link between sustainability factors and maintenance management of industrial water distribution systems, something that is fundamental in manufacturing but also in other fields of application

Reducing the anxiety of patients undergoing an oral biopsy by means of graphic novels: an open-label randomized clinical trial

Background: The use of graphic novels is a trending topic in health communication as a new form of visual storytelling which explores narratives of health care, cancer, healing, and disability. The objective of the present study was to evaluate - for the first time in the literature - the effect of graphic novels in reducing the anxiety of patients waiting for an incisional biopsy in an oral oncology setting. Material and methods: This open-label randomized clinical trial comprised 50 patients with a clinical suspicion of oral potentially malignant disorders. Twenty-five patients were randomly allocated to the test group, and a colourful graphic novel was provided. Subsequently, the Beck Depression Inventory and the Depression Anxiety Stress Scales-21 were administered to all 50 recruited patients, after which a biopsy was performed on each patient. Results: No statistically significant difference was observed between the test and control groups for the variables regarding the demographic data (p>0.2). There was a significant difference after the introduction of the graphic novel, regardless of which questionnaire was used. The graphic novel demonstrated an improvement in the ability of the test group to tolerate anxiety while waiting for an oral biopsy in both psychological tests (p<0.05). Conclusions: In light of these initial positive results, the authors of this study would like to suggest the use of graphic novels in oral oncology, dentistry, and medicine with the aim of reducing patient anxiety

A first-order stabilization-free Virtual Element Method

In this paper, we introduce a new Virtual Element Method (VEM) not requiring any stabilization term based on the usual enhanced first-order VEM space. The new method relies on a modified formulation of the discrete diffusion operator that ensures stability preserving all the properties of the differential operator.(c) 2023 Elsevier Ltd. All rights reserved

Lack of Temporal Impairment in Patients With Mild Cognitive Impairment

In the present study, we investigate possible temporal impairment in patients with mild cognitive impairment (MCI) and the amount of temporal distortions caused by the presentation of emotional facial expressions (anger, shame, and neutral) in MCI patients and controls. Twelve older adults with MCI and 14 healthy older adults were enrolled in the present study. All participants underwent a complete neuropsychological evaluation. We used three timing tasks to tap temporal abilities, namely time bisection (standard intervals lasting 400 and 1600 ms), finger-tapping (free and 1 s), and simple reaction-time tasks. The stimuli used in the time bisection task were facial emotional stimuli expressing anger or shame to investigate a possible contribution of emotional information as previously observed in healthy adults. MCI patients showed temporal abilities comparable to controls. We observed an effect of facial emotional stimuli on time perception when data were analyzed in terms of proportion of long responses, and this result was mainly driven by the temporal overestimation when a facial expression of anger was presented in controls. Results seem to suggest that the severity of the cognitive dysfunction accounts more for subjective temporal impairment than a compromised internal clock