664 research outputs found
Two-scale asymptotic homogenization of hierarchical locally resonant metamaterials in anti-plane shear conditions
Two-scale asymptotic homogenization in a MEMS auxetic structure for over etch identification
The development and optimization of Micro electro-mechanical systems (MEMS) devices, due to their small size scale, require testing and precise characterization. As an example, over etch, which is the deviation between the designed masks and the effective dimensions of the suspended parts, strongly influences the performances of MEMS; therefore, to predict the correct functioning of the device its actual value must be carefully identified. In this work, we propose an efficient, time-saving tool to identify fabrication imperfections in MEMS devices. In particular, we replace the complex geometry of a MEMS mechanical filter with an equivalent homogeneous medium, whose linear-elastic effective properties are evaluated employing two-scale asymptotic homogenization and we identify the over etch by minimizing the relative error between experimental data and corresponding predictions obtained for different combinations of over etch
Angular correlation of scattered annihilation photons, to test the possibility of hidden variables in quantum theory
Angular correlations of the annihilation photons, Compton scattered by plastic scintillators and detected by means of NaI (T1) crystals, have been measured in order to test the possibility of deviations of the experimental results from the predictions of the quantum theory
A NEW SHORT VERSION OF INTERNET GAMING DISORDER-20: AN EXPLORATORY STRUCTURAL EQUATION MODELING
Objective: The purpose of this paper was to contribute to the psychometric
properties and dimensionality of the IGD-20.
Method: An online survey was completed by 392 Italian online gamers (Mage
= 29.2, SD = 11.3; 45.2% males). A battery of self-report questionnaires was
administered to assess internet gaming disorder, internet addiction, loneliness,
anxiety, depression, stress, social-interaction anxiety, self-esteem, and perceived
social support. To test the factor structure of IGD-20, both traditional (i.e., EFA and
CFA) and innovative (i.e., ESEM) techniques were applied. Convergent, concurrent,
discriminant, and criterion-related validity were evaluated.
Results: Our study revealed the outperforming 3-factor ESEM model (χ2=39.951,
p = 0.0021; RMSEA = 0.056, 90% C.I. [0.032 - 0.079]; CFI = 0.986; TLI = 0.965;
and SRMR = 0.017; ω = .76, .77, and .79, respectively) as a new short version (IGD-
10SV) for the IGD-20. The validity of the IGD-10SV was supported by significant
associations with theoretically related measures.
Conclusions: The current findings support the adoption of the analytic ESEM
approach for complex multidimensional measures and the use of the IGD-10SV for the assessment of internet gaming disorder
Super-resolution provided by the arbitrarily strong superlinearity of the blackbody radiation
Blackbody radiation is a fundamental phenomenon in nature, and its explanation by Planck marks a cornerstone in the history of Physics. In this theoretical work, we show that the spectral radiance given by Planck's law is strongly superlinear with temperature, with an arbitrarily large local exponent for decreasing wavelengths. From that scaling analysis, we propose a new concept of super-resolved detection and imaging: if a focused beam of energy is scanned over an object that absorbs and linearly converts that energy into heat, a highly nonlinear thermal radiation response is generated, and its point spread function can be made arbitrarily smaller than the excitation beam focus. Based on a few practical scenarios, we propose to extend the notion of super-resolution beyond its current niche in microscopy to various kinds of excitation beams, a wide range of spatial scales, and a broader diversity of target objects
Fear of flying assessment: A contribution to the Italian validation of two self-report measures
The present study describes the psychometric properties of the Italian adaptation of two self-report scales for fear of flying assessment: the Flight Anxiety Situations questionnaire (FAS), which measures anxiety related to specific flying phases, and the Flight Anxiety Modality questionnaire (FAM), which focuses on somatic and cognitive modalities occurring in air travel situations. Although both questionnaires have been translated in various languages and tailored to several local frameworks, this is the only study that provides an evaluation of the adapted instruments’ validity and reliability. Validation procedures were done on 259 participants, including patients who experienced fear of flying as well as a group of non-clinical subjects. Exploratory factor analysis was used to investigate the optimal design for the dimensional structure of both instruments. Confirmatory analyses showed that the envisaged models provided an acceptable fit for the available data. A three-factor solution for FAS and a two-factor solution for FAM were therefore detected. Construct validity was supported by convergent and criterion-related data, internal consistency was satisfactory for all subscales, and both instruments revealed a high level of sensitivity to change. Overall, psychometric quality of both measures showed to be fairly good and comparable to those found in the original study, thus suggesting their application in treatment programs for non-English speakers
Optimal delivery of follow-up care after allogeneic hematopoietic stem-cell transplant: Improving patient outcomes with a multidisciplinary approach
U-Sleep's resilience to AASM guidelines
AASM guidelines are the result of decades of efforts aiming at standardizing
sleep scoring procedure, with the final goal of sharing a worldwide common
methodology. The guidelines cover several aspects from the technical/digital
specifications,e.g., recommended EEG derivations, to detailed sleep scoring
rules accordingly to age. Automated sleep scoring systems have always largely
exploited the standards as fundamental guidelines. In this context, deep
learning has demonstrated better performance compared to classical machine
learning. Our present work shows that a deep learning based sleep scoring
algorithm may not need to fully exploit the clinical knowledge or to strictly
adhere to the AASM guidelines. Specifically, we demonstrate that U-Sleep, a
state-of-the-art sleep scoring algorithm, can be strong enough to solve the
scoring task even using clinically non-recommended or non-conventional
derivations, and with no need to exploit information about the chronological
age of the subjects. We finally strengthen a well-known finding that using data
from multiple data centers always results in a better performing model compared
with training on a single cohort. Indeed, we show that this latter statement is
still valid even by increasing the size and the heterogeneity of the single
data cohort. In all our experiments we used 28528 polysomnography studies from
13 different clinical studies
Quantum Mechanics and Leggett's Inequalities
We show that when the proper description of the behaviour of individual
photons or spin 1/2 particles in a spherically symmetric entangled pair is done
through the use of the density matrix, the Leggett's inequality is not violated
by quantum mechanics.Comment: 7 pages, no figures. A missing global sign in the r.h.s. of eq.
(4.10) in section 4 of version 1 (v1) invalidates the conclusion of that
particular section, which is then suppressed in the present version (v2
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