Search results for "Entropy"
showing 10 items of 496 documents
Optimal Placement of Pressure Sensors Using Fuzzy DEMATEL-Based Sensor Influence
2020
[EN] Nowadays, optimal sensor placement (OSP) for leakage detection in water distribution networks is a lively field of research, and a challenge for water utilities in terms of network control, management, and maintenance. How many sensors to install and where to install them are crucial decisions to make for those utilities to reach a trade-off between efficiency and economy. In this paper, we address the where-to-install-them part of the OSP through the following elements: nodes' sensitivity to leakage, uncertainty of information, and redundancy through conditional entropy maximisation. We evaluate relationships among candidate sensors in a network to get a picture of the mutual influenc…
Fokker–Planck equation with respect to heat measures on loop groups
2011
Abstract The Dirichlet form on the loop group L e ( G ) with respect to the heat measure defines a Laplacian Δ DM on L e ( G ) . In this note, we will use Wasserstein distance variational method to solve the associated heat equation for a given data of finite entropy.
Sobolev estimates for optimal transport maps on Gaussian spaces
2012
We will study variations in Sobolev spaces of optimal transport maps with the standard Gaussian measure as the reference measure. Some dimension free inequalities will be obtained. As application, we construct solutions to Monge-Ampere equations in finite dimension, as well as on the Wiener space.
La sopravvivenza immediata delle start-up italiane del settore manifatturiero sanitario: un'analisi multilevel
2017
The immediate survival of the Italian start-up businesses in healthcare industry: a multilevel analysis Objectives: The purpose of this contribution is to provide novel evidence about the main determinants of the short-run survival of pharmaceutical and medical device manufacturing start-up firms in Italy. In order to assess both the firm-specific determinants and the observed and unobserved regional and contextual characteristics, we model the three-year firm survival probability by means of a multilevel logistic framework. Methods and Results: The empirical analysis focuses on an internationally comparable database of the population of firms built up and managed by the Italian National In…
A fuzzy approach to the evaluation of image complexity
2009
The inherently multidimensional problem of evaluating the complexity of an image is of a certain relevance in both computer science and cognitive psychology. Computer scientists usually analyze spatial dimensions in order to deal with automatic vision problems, such as feature extraction. Psychologists seem more interested in the temporal dimension of complexity, as a means to explore attentional models. Is it possible to define, by merging both approaches, a more general index of visual complexity? The aim of this paper is the definition of objective measures of image complexity that fits with the so named perceived time. Towards the end we have defined a fuzzy mathematical model of visual…
Polymer solutions: Equilibrium clusters versus shear clusters
2021
Abstract Polymer solutions are inhomogeneous on mesoscopic scales as a result of chemical bonds linking their monomeric units. This situation leads to polymer clusters within which the polymer concentration c cluster is only a small fraction of the overall concentration c. The ratio c/ c cluster (overlap parameters Ω ) quantifies the number of clusters that need to overlap to yield c. Equilibrium clusters (minimization of Gibbs energy) and shear clusters (minimization of entropy production) differ fundamentally where Ω equil ≥ Ω shear . Only in the vicinity of the glass transition temperature and at high concentration the opposite is the case. Experimental information on Ω equil as a functi…
A derivation of the isothermal quantum hydrodynamic equations using entropy minimization
2005
Isothermal quantum hydrodynamic equations of order O(h 2 ) using the quantum entropy minimization method recently developed by Degond and Ringhofer are derived. The equations have the form of the usual quantum hydrodynamic model including a correction term of order O(h 2 ) which involves the vorticity. If the initial vorticity is of order 0(h), the standard model is obtained up to order O(h 4 ). The derivation is based on a careful expansion of the quantum equilibrium obtained from the entropy minimization in powers of h 2 .
Evidence for substrate binding-induced zwitterion formation in the catalytic Cys-His dyad of the SARS-CoV main protease.
2014
The coronavirus main protease (M(pro)) represents an attractive drug target for antiviral therapy of coronavirus (CoV) infections, including severe acute respiratory syndrome (SARS). The SARS-CoV M(pro) and related CoV proteases have several distinct features, such as an uncharged Cys-His catalytic dyad embedded in a chymotrypsin-like protease fold, that clearly separate these enzymes from archetypical cysteine proteases. To further characterize the catalytic system of CoV main proteases and to obtain information about improved inhibitors, we performed comprehensive simulations of the proton-transfer reactions in the SARS-CoV M(pro) active site that lead to the Cys(-)/His(+) zwitterionic st…
Vibrational spectrum of the spin crossover complex [Fe(phen)(2)(NCS)(2)] studied by IR and Raman spectroscopy, nuclear inelastic scattering and DFT c…
2006
The vibrational modes of the low-spin and high-spin isomers of the spin crossover complex [Fe(phen)(2)(NCS)(2)] (phen = 1,10-phenanthroline) have been measured by IR and Raman spectroscopy and by nuclear inelastic scattering. The vibrational frequencies and normal modes and the IR and Raman intensities have been calculated by density functional methods. The vibrational entropy difference between the two isomers, DeltaS(vib), which is--together with the electronic entropy difference DeltaS(el)--the driving force for the spin-transition, has been determined from the measured and from the calculated frequencies. The calculated difference (DeltaS(vib) = 57-70 J mol(-1) K(-1), depending on the m…
A DFT study of [3 + 2] cycloaddition reactions of an azomethine imine with N-vinyl pyrrole and N-vinyl tetrahydroindole
2016
The mechanism and selectivities of the [3+2] cycloaddition (32CA) reactions of azomethine imine (AI) 8 with two N-vinyl five-membered heterocycles (NVFH), 9a and 9b, have been theoretically studied using DFT methods at the MPWB1K/6-31G(d) computational level. The possible ortho/meta regio- and endo/exo stereoselective channels were explored and characterised. The low polar character of these 32CA reactions, which is the consequence of the high nucleophilic character of both reagents, as well as the non-effective reactivity of these NVFH as nucleophiles, accounts for the high calculated activation energies, 16.1 (9a) and 16.8 (9b) kcalmol-1 in chlorobenzene. Analysis of the relative electron…