Search results for " graph"

Interfaces and Environments

2011

Tautomerism in pyridazin-3(2H)-one: a theoretical study using implicit/explicit solvation models.

2013

Abstract The tautomeric conversion of pyridazin-3(2H)-one 1 into pyridazin-3-ol 2 has been theoretically studied using density functional theory (DFT) methods at the B3LYP/6-311++G** level. Two mechanisms have been considered for this process: (i) one in which the hydrogen is directly transferred through TS12; and (ii) another one in which a double hydrogen transfer takes place via TS1122 upon formation of the corresponding dimer. The former requires a very high activation energy of 42.64 kcal/mol as a consequence of the strain associated with the formation of the four-membered TS12, while the latter requires a much lower activation energy, 14.66 kcal/mol. Implicit, explicit, and a combinat…

From determination of the fugacity coefficients to estimation of hydrogen storage capacity: A convenient theoretical method

2015

Abstract The equation of state (EOS) from virial expansion (VE) is used in this work to pave the way for determining the fugacity coefficients of the hydrogen fluid at arbitrary temperature and pressure. The fugacity coefficients from our VE method have more physical meanings than the empirical values. In this way, the hydrogen storage capacity of a novel material model can be estimated by using few density functional theory (DFT) calculations with the aid of a continuum model. The efficient continuum model can provide a more accurate estimation of the hydrogen storage capacity than the pure DFT calculations. Furthermore, the expensive grand canonical ensemble (μNT) simulations combining wi…

An Efficient Algorithm for Helly Property Recognition in a Linear Hypergraph

2001

International audience; In this article we characterize bipartite graphs whose associated neighborhood hypergraphs have the Helly property. We examine incidence graphs both hypergraphs and linear hypergraphs and we give a polynomial algorithm to recognize if a linear hypergraph has the Helly property.

A Tsetlin Machine with Multigranular Clauses

2019

The recently introduced Tsetlin Machine (TM) has provided competitive pattern recognition accuracy in several benchmarks, however, requires a 3-dimensional hyperparameter search. In this paper, we introduce the Multigranular Tsetlin Machine (MTM). The MTM eliminates the specificity hyperparameter, used by the TM to control the granularity of the conjunctive clauses that it produces for recognizing patterns. Instead of using a fixed global specificity, we encode varying specificity as part of the clauses, rendering the clauses multigranular. This makes it easier to configure the TM because the dimensionality of the hyperparameter search space is reduced to only two dimensions. Indeed, it tur…

Hyperspectral Texture Metrology Based on Joint Probability of Spectral and Spatial Distribution

2021

International audience; Texture characterization from the metrological point of view is addressed in order to establish a physically relevant and directly interpretable feature. In this regard, a generic formulation is proposed to simultaneously capture the spectral and spatial complexity in hyperspectral images. The feature, named relative spectral difference occurrence matrix (RSDOM) is thus constructed in a multireference, multidirectional, and multiscale context. As validation, its performance is assessed in three versatile tasks. In texture classification on HyTexiLa, content-based image retrieval (CBIR) on ICONES-HSI, and land cover classification on Salinas, RSDOM registers 98.5% acc…

Quantitative colorimetric-imaging analysis of nickel in iron meteorites.

2011

A quantitative analytical imaging approach for determining the nickel content of metallic meteorites is proposed. The approach uses a digital image of a series of standard solutions of the nickel-dimethylglyoxime coloured chelate and a meteorite sample solution subjected to the same treatment as the nickel standards for quantitation. The image is processed with suitable software to assign a colour-dependent numerical value (analytical signal) to each standard. Such a value is directly proportional to the analyte concentration, which facilitates construction of a calibration graph where the value for the unknown sample can be interpolated to calculate the nickel content of the meteorite. The…

An MDE Approach for Rapid Prototyping and Implementation of Dynamic Reconfigurable Systems

2015

This article presents a co-design methodology based on RecoMARTE, an extension to the well-known UML MARTE profile, which is used for the specification and automatic generation of Dynamic and Partially Reconfigurable Systems-on-Chip (DRSoC). This endeavor is part of a larger framework in which Model-Driven Engineering (MDE) techniques are extensively used for modeling and via model transformations, generating executable models, which are exploited by implementation tools to create reconfigurable systems. More specifically, the methodological aspects presented in this article are concerned with expediting the conception and implementation of the hardware platform and the integration of corre…

A complex network analysis of inbound tourism in Sicily

2019

In this article, the complex dynamics of inbound tourism in Sicily is analyzed for the period 1998–2017. The horizontal visibility graph algorithm is used to transform the overnight stays' time series into a network whose topology is investigated by standard network analysis. Discontinuities in the domestic and international tourism demand were identified in order to detect signals of change and the timing of the directional change in tourism growth. The network degree distribution confirms the complex structure of the destination and reveals the random and thus more unpredictable nature of the international tourism demand in Sicily, compared with a more stable domestic segment. Some policy…

An Iconic Framework for Learning the Art of Programming

2016

The integration of programming teachings, in all levels of education, highlights the need to acquire the art of programming for each individual student through versatile tools based on specific cognitive methods. Diversified linguistic metaphors have to be adopted by the developing frame, in order to highlight the qualities of each student. Therefore, a framework, oriented to learning the art of programming, must foster polychrome constructs representations, a number of data structures and an intuitive interfaces in order to make easier to understand the evolution of the algorithm that have to be developed. The following contribution will present a theoretical formalization of a framework f…