Search results for "multi-layer"
showing 10 items of 23 documents
Generalised bisection method for optimum ultrasonic ray tracing and focusing in multi-layered structures
2021
Ultrasonic testing has been used for many decades, proving itself very efficient for detecting defects in many industrial sectors. The desire to apply ultrasonic testing to geometrically complex structures, and to anisotropic, inhomogeneous materials, together with the advent of more powerful electronics and software, is constantly pushing the applicability of ultrasonic waves to their limits. General ray tracing models, suitable for calculating the proper incident angle of single element probes and the proper time delay of phased array, are currently required. They can support the development of new imaging techniques, as Full Matrix Capture and Total Focusing Method, and the execution of …
Derivatives and inverse of a linear-nonlinear multi-layer spatial vision model
2016
Linear-nonlinear transforms are interesting in vision science because they are key in modeling a number of perceptual experiences such as color, motion or spatial texture. Here we first show that a number of issues in vision may be addressed through an analytic expression of the Jacobian of these linear-nonlinear transforms. The particular model analyzed afterwards (an extension of [Malo & Simoncelli SPIE 2015]) is illustrative because it consists of a cascade of standard linear-nonlinear modules. Each module roughly corresponds to a known psychophysical mechanism: (1) linear spectral integration and nonlinear brightness-from-luminance computation, (2) linear pooling of local brightness…
Risks of mould growth in different building structures
2014
In the current paper the impact of real Latvian climate conditions on a variety of building constructions is inspected. The influence of the humidity on buildings’ sustainability in three different building units has been appraised. Condensate risks in a multi-layer wall are analyzed by transient outdoor climatic conditions. Risks of mould growth are discussed in detail taking into account the properties of building materials, dependence of humidity on temperature and season. The effect of vapour barrier is analyzed from several aspects. Theoretical analysis has been done based on real test stands built in Riga. Some experimental results are obtained.
Appropriazione e (ri)semantizzazione dello spazio urbano: lo sport in una piazza palermitana
2019
Il contributo, attraverso uno studio di campo, con un approccio geografico culturale esplora le modalità attraverso cui uno spazio urbano, piazza Vittorio Emanuele Orlando a Palermo, può essere oggetto di complessi processi di (ri)semantizzazione. La piazza diviene infatti luogo per sport giovanili improvvisati, al centro di dialettiche opposte (ufficialità/improvisazione) e di forme multistratificate di socialità e aggregazione.
An optimal dimensioning method of a green wall structure for noise pollution reduction
2021
International audience; This paper concern the optimization of a multilayered green wall structure including substrate and foliage in order to reduce as much as possible backward noise reflection and forward transmission from the wall. Each component involved in the wall structure is fully characterized experimentally to get its transfer matrix. Simulation demonstrated that foliage layer superimposed to substrate layer doesn’t affect the transmission losses but contributes greatly to the increase of return losses of the green wall structure. To achieve the best performances in terms of return and forward losses as well as frequency bandwidth, the methods of optimization are discussed inclu…
An assessment of energy vulnerability in Small Island Developing States
2020
Abstract Small Island Developing States (SIDS) suffer from several structural characteristics that jeopardize their ability to achieve a sustainable energy future. Their reliance on imported fossil fuels exacerbates their exposure to external threats on international energy markets. Their energy systems are also exposed to internal disturbances that disrupt the proper production, transmission and distribution of energy. The aim of this paper is to investigate the extent to which island energy systems are vulnerable to shocks and internal dysfunctions over which they have no control. For this purpose, we build a composite index of energy vulnerability using the Multi-Layer Benefit-of-the-Dou…
Degradation and Recycling of Films Based on Biodegradable Polymers: A Short Review
2019
The environmental performance of biodegradable materials has attracted attention from the academic and the industrial research over the recent years. Currently, degradation behavior and possible recyclability features, as well as actual recycling paths of such systems, are crucial to give them both durability and eco-sustainability. This paper presents a review of the degradation behaviour of biodegradable polymers and related composites, with particular concern for multi-layer films. The processing of biodegradable polymeric films and the manufacturing and properties of multilayer films based on biodegradable polymers will be discussed. The results and data collected show that: poly-lactic…
Air pollution in European countries and life expectancy—modelling with the use of neural network
2019
Abstract The present paper discusses a novel methodology based on neural network to determine air pollutants’ correlation with life expectancy in European countries. The models were developed using historical data from the period 1992–2016, for a set of 20 European countries. The subject of the analysis included the input variables of the following air pollutants: sulphur oxides, nitrogen oxides, carbon monoxide, particulate matters, polycyclic aromatic hydrocarbons and non-methane volatile organic compounds. Our main findings indicate that all the variables significantly affect life expectancy. Sensitivity of constructed neural networks to pollutants proved to be particularly important in …
Neural Modeling of Greenhouse Gas Emission from Agricultural Sector in European Union Member Countries
2018
The present paper discusses a novel methodology based on neural network to determine agriculture emission model simulations. Methane and nitrous oxide are the key pollutions among greenhouse gases being a major contribution to climate changes because of their high potential global impact. Using statistical clustering (k-means and Ward’s method), five meaningful clusters of countries with similar level of greenhouse gases emission were identified. Neural modeling using multi-layer perceptron networks was performed for countries placed in particular groups. The parameters that characterize the quality of a network are the predictive errors (mainly validation and test) and they are high (0.97–…
IMPLICIT MESH DISCONTINUOUS GALERKIN FOR VARIABLE ANGLE TOW MULTILAYERED PLATES
2018
This works presents a novel computational scheme for variable angle tow (VAT) multilayered plates [1]. The characteristic features of the proposed scheme are the combined use of a discontinuous Galerkin (dG) formulation and an implicitly defined mesh. The formulation is based on the principle of virtual displacements (PVD) and the Equivalent Single Layer (ESL) assumption for the mechanical behavior of the VAT plates [2]. The problem is first placed within the dG framework by suitably introducing an auxiliary variable and by rewriting the set of equations governing ESL VAT plates as a firstorder system of differential equations. Following Arnold et al.[3] and by introducing suitably defined …