Search results for " Threshold"

Microwave response properties of epoxy resin composites filled with graphitic fillers

2014

Composite materials based on epoxy resin filled with various kinds of graphite particles: exfoliated graphite (EG), natural graphite, and coarse, medium and fine artificial graphites have been prepared. The dielectric permittivity strongly increases with graphite particle size. This effect is related to the distance of the investigated filler concentrations to the composites' percolation threshold. Microwave experiments show that exfoliated graphite is, out of investigated graphite particles, the only one being a really effective additive for producing electromagnetic (EM) interference (EMI) shielding: 2 wt.% epoxy/EG is absolutely opaque to electromagnetic radiation at 30 GHz.

Multilevel preconditioning and adaptive sparse solution of inverse problems

2012

Percolation on correlated random networks

2011

We consider a class of random, weighted networks, obtained through a redefinition of patterns in an Hopfield-like model and, by performing percolation processes, we get information about topology and resilience properties of the networks themselves. Given the weighted nature of the graphs, different kinds of bond percolation can be studied: stochastic (deleting links randomly) and deterministic (deleting links based on rank weights), each mimicking a different physical process. The evolution of the network is accordingly different, as evidenced by the behavior of the largest component size and of the distribution of cluster sizes. In particular, we can derive that weak ties are crucial in o…

An integrated assessment of the Good Environmental Status of Mediterranean Marine Protected Areas

2022

Este artículo contiene 11 páginas, 2 figuras, 2 tablas.

An Adaptive Alternating Direction Method of Multipliers

2021

AbstractThe alternating direction method of multipliers (ADMM) is a powerful splitting algorithm for linearly constrained convex optimization problems. In view of its popularity and applicability, a growing attention is drawn toward the ADMM in nonconvex settings. Recent studies of minimization problems for nonconvex functions include various combinations of assumptions on the objective function including, in particular, a Lipschitz gradient assumption. We consider the case where the objective is the sum of a strongly convex function and a weakly convex function. To this end, we present and study an adaptive version of the ADMM which incorporates generalized notions of convexity and penalty…

Data Acquisition System for the Characterization of Biomechanical and Ergonomic Thresholds in Driving Vehicles

2020

Directive (EU) 2015/653 on driving licenses has involved the modification of different codes that must appear on driver&rsquo

What is the best fitting function? Evaluation of lactate curves with common methods from the literature

2015

Using the lactate threshold for training prescription is the gold-standard, although there are several open questions. One open question is: What is the best fitting method for the load-lactate data points? This investigation re-analyses over 3500 lactate diagnostic datasets in swimming. Our evaluation software examines six different fitting methods with two different minimization criteria (RMSE and SE). Optimization of parameters of the functions is put in excecution with gradient descent. From a mathematical point of view, the double phase model, which consists of two linear regression lines, shows the least errors (RMSE min 0.254 ± 0.172; SE min 0.311 ± 0.210). However, this method canno…

Denoising 3D Models with Attributes using Soft Thresholding

2004

International audience; Recent advances in scanning and acquisition technologies allow the construction of complex models from real world scenes. However, the data of those models are generally corrupted by measurement errors. This paper describes an efficient single pass algorithm for denoising irregular meshes of scanned 3D model surfaces. In this algorithm, the frequency content of the model is assessed by a multiresolution analysis that requires only 1-ring neighbourhood without any particular parameterization of the model faces. Denoising is achieved by applying the soft thresholding method to the detail coefficients given by the multiresolution analysis. Our method is suitable for irr…

Serum uric acid levels threshold for mortality in diabetic individuals: The URic acid Right for heArt Health (URRAH) project

2022

Background and aim: The URRAH (URic acid Right for heArt Health) Study has identified cut-off values of serum uric acid (SUA) predictive of total mortality at 4.7 mg/dl, and cardiovascular (CV) mortality at 5.6 mg/dl. Our aim was to validate these SUA thresholds in people with diabetes. Methods and results: The URRAH subpopulation of people with diabetes was studied. All-cause and CV deaths were evaluated at the end of follow-up. A total of 2570 diabetic subjects were studied. During a median follow-up of 107 months, 744 deaths occurred. In the multivariate Cox regression analyses adjusted for several confounders, subjects with SUA ≥5.6 mg/dl had higher risk of total (HR: 1.23, 95%CI: 1.04-…

Dual-kind Q-switching of erbium fiber laser

2014

Two different regimes of Q-switching in the same implementation of an actively Q-switched erbium-doped fiber laser are demonstrated. Depending on the active fiber length and repetition rate of an intracavity Q-cell (acousto-optic modulator), the laser operates either in the regime of common, rather long and low-power, pulses composed of several sub-pulses or in the one of very short and powerful stimulated Brillouin scattering-induced pulses. The basic physical reason of the laser system to oscillate in one of these two regimes is the existence or absence of CW narrow-line “bad-cavity” lasing in the intervals when the Q-cell is blocked.