Search results for "Computation"
showing 10 items of 7362 documents
Computational Studies of Materials for Energy Technology: CO2 Methanation, and Halloysite Carbon-Coating
2022
The models and theories of quantum chemistry are applied in order to study two kinds of materials of interest in the field of energy technology, to understand their behavior and to verify their suitability for possible application. In particular, the effect of single Ru/Fe atom deposition on the CO2 methanation reaction occurring on the Ni(111) surface, and the effect on the band gap produced by carbon atom deposition and carbon cluster accretion on the silicic surface of halloysite, have been investigated by means of the periodic and molecular flavours of density functional theory. In order to accomplish the investigations above two entirely new computer codes were written and are actually…
Universal freezing of quantum correlations within the geometric approach
2015
Quantum correlations in a composite system can be measured by resorting to a geometric approach, according to which the distance from the state of the system to a suitable set of classically correlated states is considered. Here we show that all distance functions, which respect natural assumptions of invariance under transposition, convexity, and contractivity under quantum channels, give rise to geometric quantifiers of quantum correlations which exhibit the peculiar freezing phenomenon, i.e., remain constant during the evolution of a paradigmatic class of states of two qubits each independently interacting with a non-dissipative decohering environment. Our results demonstrate from first …
An order-adaptive compact approximation Taylor method for systems of conservation laws
2021
Abstract We present a new family of high-order shock-capturing finite difference numerical methods for systems of conservation laws. These methods, called Adaptive Compact Approximation Taylor (ACAT) schemes, use centered ( 2 p + 1 ) -point stencils, where p may take values in { 1 , 2 , … , P } according to a new family of smoothness indicators in the stencils. The methods are based on a combination of a robust first order scheme and the Compact Approximate Taylor (CAT) methods of order 2p-order, p = 1 , 2 , … , P so that they are first order accurate near discontinuities and have order 2p in smooth regions, where ( 2 p + 1 ) is the size of the biggest stencil in which large gradients are n…
On the modern use of the bòvedas tabicadas
2009
The paper concerns the study of the so-called “bòvedas tabicadas” (i.e. thin vaults constituted by layers of “rasillas” suitably superimposed) based on the results obtained by specific experimental investigations effected on the material of which they are constituted as well as on a vault that is still working. In particular, aim of the present research is the implementation of a first analysis of the structure in its present configuration (often unusable), with the purpose to evaluate the real structure serviceability related to the prescribed intensity of the acting loads, and moreover the execution of a new second analysis of the same structure but suitably reinforced by placing further …
FE modeling of Partially Steel-Jacketed (PSJ) RC columns using CDP model
2018
This paper deepens the finite element modeling (FEM) method to reproduce the compressive behavior of partially steel-jacketed (PSJ) RC columns by means of the Concrete Damaged Plasticity (CDP) Model available in ABAQUS software. Although the efficiency of the CDP model is widely proven for reinforced concrete columns at low confining pressure, when the confinement level becomes high the standard plasticity parameters may not be suitable to obtain reliable results. This paper deals with these limitations and presents an analytically based strategy to fix the parameters of the Concrete Damaged Plasticity (CDP) model. Focusing on a realistic prediction of load-bearing capacity of PSJ RC column…
Sviluppi della Intelligenza Computazionale: l'esempio del Sarcasm Detection
2016
Dopo un periodo prolungato in cui vigeva uno scarto persistente tra l’ottimismo dato dai grandi proclami di ricerca e la scarsità e frammentarietà di risultati veri e tangibili, viviamo (finalmente) nell’era delle grandi conquiste dell’Intelligenza Artificiale
A MULTI-LAYER MODEL TO STUDY GENOME-SCALE POSITIONS OF NUCLEOSOMES
2007
The positioning of nucleosomes along chromatin has been implicated in the regulation of gene expression in eukaryotic cells, because packaging DNA into nucleosomes affects sequence accessibility. In this paper we propose a new model (called MLM) for the identification of nucleosomes and linker regions across DNA, consisting in a thresholding technique based on cut-set conditions. For this purpose we have defined a method to generate synthetic microarray data fully inspired from the approach that has been used by Yuan et al. Results have shown a good recognition rate on synthetic data, moreover, the $MLM$ shows a good agreement with the recently published method based on Hidden Markov Model …
Birkhoff's aesthetics, Arnheim's entropy. Some remarks on complexity and fuzzy entropy in arts
2015
A judgement of aesthetic in arts is, by sheer consensus, a daunting task that requires evaluation of a whole host of endogenous and exogenous cultural factors. A few of them can actually provide very useful hints in tackling foundational problems in Information Science in a more natural setting than what is usually provided by a typical engineering stance. This interaction can however work the other way about, as instruments from the Information and Computer Science toolkit may help in focusing the less explored features of art and its evaluation. When all the social, historical, hermeneutical and political considerations are stripped from the living flesh of the piece, we lose most of wha…
Algorithmic paradigms for stability-based cluster validity and model selection statistical methods, with applications to microarray data analysis
2012
AbstractThe advent of high throughput technologies, in particular microarrays, for biological research has revived interest in clustering, resulting in a plethora of new clustering algorithms. However, model selection, i.e., the identification of the correct number of clusters in a dataset, has received relatively little attention. Indeed, although central for statistics, its difficulty is also well known. Fortunately, a few novel techniques for model selection, representing a sharp departure from previous ones in statistics, have been proposed and gained prominence for microarray data analysis. Among those, the stability-based methods are the most robust and best performing in terms of pre…
M-VIF: A machine-vision based on information fusion
2002
The authors describe a new architecture for machine vision, which is based on information fusion approach. Its general design has been developed by using a formal computation model that integrates three main ingredients of the visual computation: the data, the models, and the algorithms. The hardware design and the software environment of M-VIF are also given. The simulation of M-VIF is under development on the HERMIA-machine.