Search results for "Matrix"
showing 10 items of 3205 documents
IMAGE PROCESSING IN POLLUTION VULNERABILITY ASSESSMENT OF SICILY AQUIFERS
2009
It is generally acknowledged that vulnerability mapping represents an essential tool for territory management. Intrinsic vulnerability can be generally described as “the susceptibility of the aquifer systems, in their different components and in different geometric and hydrodynamics situations, to swallow and diffuse, also mitigating the effects, a fluid or water-transported pollutant, in such a way to produce impact on the groundwater quality, in space and time”. Assessment procedures of vulnerability consider a number of parameters, the estimation of which is usually difficult and very often insufficient to correctly represent aquifer’s features. As aquifers are closely influenced by nume…
A FTIR study on low hydration saccharide amorphous matrices: Thermal behaviour of the Water Association Band
2011
Abstract We report a study on the thermal behaviour of the infrared Water Association Band (WAB) in dry binary saccharide–water systems (containing trehalose, sucrose, maltose, and raffinose). This is a follow-up of preceding studies on analogous carboxymyoglobin-saccharide–water ternary systems, which pointed out a mutual protein-matrix influence (coupling). A comparison between binary and ternary systems, for all the saccharides studied, evidences a reduction in the residual water content in the latter and, except for trehalose, a sizable modification in the thermal behaviour, which is discussed in terms of structure and hydrogen bonding properties of the sugars. The study allowed us also…
OpenMolcas: From Source Code to Insight
2019
In this article we describe the OpenMolcas environment and invite the computational chemistry community to collaborate. The open-source project already includes a large number of new developments realized during the transition from the commercial MOLCAS product to the open-source platform. The paper initially describes the technical details of the new software development platform. This is followed by brief presentations of many new methods, implementations, and features of the OpenMolcas program suite. These developments include novel wave function methods such as stochastic complete active space self-consistent field, density matrix renormalization group (DMRG) methods, and hybrid multico…
Quantum wire with periodic serial structure
1991
Electron wave motion in a quantum wire with periodic structure is treated by direct solution of the Schr\"odinger equation as a mode-matching problem. Our method is particularly useful for a wire consisting of several distinct units, where the total transfer matrix for wave propagation is just the product of those for its basic units. It is generally applicable to any linearly connected serial device, and it can be implemented on a small computer. The one-dimensional mesoscopic crystal recently considered by Ulloa, Casta\~no, and Kirczenow [Phys. Rev. B 41, 12 350 (1990)] is discussed with our method, and is shown to be a strictly one-dimensional problem. Electron motion in the multiple-stu…
Improving the transmittance of an epsilon-near-zero-based wavefront shaper
2016
Although Epsilon-Near-Zero metamaterials (ENZ) offer many unconventional ways to play with light, the optical impedance mismatch with surroundings can limit the efficiency of future devices. We report here on the improvement of the transmittance of an Epsilon-Near-Zero (ENZ) wavefront shaper. We first address in this paper the way to enhance the transmittance of a plane wave through a layer of ENZ material thanks to a numerical optimization approach based on the Transfer Matrix Method. We then transpose the one dimensional approach to a two dimensional case where the emission of a dipole is shaped into a plane wave by an ENZ device with a design that optimizes the transmittance. As a result…
Image transmission through dynamic scattering media by single-pixel photodetection
2014
Smart control of light propagation through highly scattering media is a much desired goal with major technological implications. Since interaction of light with highly scattering media results in partial or complete depletion of ballistic photons, it is in principle impossible to transmit images through distances longer than the extinction length. Nevertheless, different methods for image transmission, focusing, and imaging through scattering media by means of wavefront control have been published over the past few years. In this paper we show that single-pixel optical systems, based on compressive detection, can also overcome the fundamental limitation imposed by multiple scattering to suc…
Laser Cladding of TiC for Better Titanium Components
2011
Pure commercial titanium is widely used because of its high corrosion resistance and lower cost compared with other titanium alloys, in particular when there is no high wear requirements. Nevertheless, the wear resistance is poor and surface damage usually occurs in areas under contact loadings. Laser cladding is a suitable technique for manufacturing precise and defect free coatings of a dissimilar material with higher wear and corrosion resistance. In this work a good understanding of laser metal deposition mechanisms allowed to obtain defect free coatings of Ti6Al4V and TiC metal matrix composite (MMC) using a flash lamp pumped Nd:YAG laser of 1 kW. A complete investigation of the proces…
Anomaly Detection from Network Logs Using Diffusion Maps
2011
The goal of this study is to detect anomalous queries from network logs using a dimensionality reduction framework. The fequencies of 2-grams in queries are extracted to a feature matrix. Dimensionality reduction is done by applying diffusion maps. The method is adaptive and thus does not need training before analysis. We tested the method with data that includes normal and intrusive traffic to a web server. This approach finds all intrusions in the dataset. peerReviewed
Editorial - Connecting the Dots: The Promises of Wharton's Jelly Mesenchymal Stem Cells for Tissue Repair and Regeneration
2011
Mesenchymal stem cells (MSC) constitute a variety of cellular populations which were described first about 35 years ago in the bone marrow (BM) stroma [1]. These years have foreseen an exponential increase of reports pointing out features, stemness, markers, tissue sources and clinical applications of these cells. Cells with MSC features can be isolated from virtually every adult organ in the body, as well from a group of fetus-associated sources (cells derived from the latter tissues are collectively known as perinatal stem cells) [2]. In recent years, the umbilical cord arose as a promising source of mesenchymal stem cells, which can be isolated in relatively high numbers (compared to BM)…
Wind Shear On-Line Identification for Unmanned Aerial Systems
2014
An algorithm to perform the on line identification of the wind shear components suitable for the UAS characteristics has been implemented. The mathematical model of aircraft and wind shear in the augmented state space has been built without any restrictive assumption on the dynamic of wind shear. Due to the severe accelerations on the aircraft induced by the strong velocity variation typical of wind shear, the wind shear effects have been modeled as external forces and moments applied on the aircraft. The identification problem addressed in this work has been solved by using the Filter error method approach. An Extended Kalman Filter has been developed to propagate state. It has been tuned …