Search results for " computational"
showing 10 items of 661 documents
Linearly implicit-explicit schemes for the equilibrium dispersive model of chromatography
2018
Abstract Numerical schemes for the nonlinear equilibrium dispersive (ED) model for chromatographic processes with adsorption isotherms of Langmuir type are proposed. This model consists of a system of nonlinear, convection-dominated partial differential equations. The nonlinear convection gives rise to sharp moving transitions between concentrations of different solute components. This property calls for numerical methods with shock capturing capabilities. Based on results by Donat, Guerrero and Mulet (Appl. Numer. Math. 123 (2018) 22–42), conservative shock capturing numerical schemes can be designed for this chromatography model. Since explicit schemes for diffusion problems can pose seve…
Relativistic DFT Calculation of (119)Sn Chemical Shifts and Coupling Constants in Tin Compounds.
2006
The nuclear shielding and spin-spin coupling constants of (119)Sn in stannane, tetramethylstannane, methyltin halides Me4-nSnXn (X = Cl, Br, I; n = 1-3), tin halides, and some stannyl cations have been investigated computationally by DFT methods and Slater all-electron basis sets, including relativistic effects by means of the zeroth order regular approximation (ZORA) method up to spin-orbit coupling. Calculated (119)Sn chemical shifts generally correlate well with experimental values, except when several heavy halogen atoms, especially iodine, are bound to tin. In such cases, calculated chemical shifts are almost constant at the scalar (spin-free) ZORA level; only at the spin-orbit level i…
The interaction of DNA with metal complexes: experimental and computational studies
2011
Modeling crowd dynamics through coarse-grained data analysis
2018
International audience; Understanding and predicting the collective behaviour of crowds is essential to improve the efficiency of pedestrian flows in urban areas and minimize the risks of accidents at mass events. We advocate for the development of crowd traffic management systems, whereby observations of crowds can be coupled to fast and reliable models to produce rapid predictions of the crowd movement and eventually help crowd managers choose between tailored optimization strategies. Here, we propose a Bi-directional Macroscopic (BM) model as the core of such a system. Its key input is the fundamental diagram for bi-directional flows, i.e. the relation between the pedestrian fluxes and d…
Openness and staff training as antecedents of administration and management innovation: a cross-country study
2020
A firm's ability to innovate has gained continuously increasing attention among scholars and practitioners. This study aims to discuss the relationship of a firm's openness as an element of organisational culture and staff training as an element of organisational learning to its activity in introducing administration and management innovation in two countries. Data collection was conducted in Latvia and Russia. To make the research more specific, organisational innovation is broken down into two categories: innovation in management practices; and innovation in workplace organisation. The result obtained demonstrated the positive impact of staff training on innovation activities and openness…
FO^2 with one transitive relation is decidable
2013
We show that the satisfiability problem for the two-variable first-order logic, FO^2, over transitive structures when only one relation is required to be transitive, is decidable. The result is optimal, as FO^2 over structures with two transitive relations, or with one transitive and one equivalence relation, are known to be undecidable, so in fact, our result completes the classification of FO^2-logics over transitive structures with respect to decidability. We show that the satisfiability problem is in 2-NExpTime. Decidability of the finite satisfiability problem remains open.
Indefinite integrals involving Jacobi polynomials from integrating factors
2020
A method was presented recently for deriving integrals of special functions using two kinds of integrating factor for the homogeneous second-order linear differential equations which many special f...
Indefinite integrals of special functions from hybrid equations
2019
Elementary linear first and second order differential equations can always be constructed for twice differentiable functions by explicitly including the function's derivatives in the definition of ...
Indefinite integrals of Lommel functions from an inhomogeneous Euler–Lagrange method
2015
ABSTRACTA method given recently for deriving indefinite integrals of special functions which satisfy homogeneous second-order linear differential equations has been extended to include functions which obey inhomogeneous equations. The extended method has been applied to derive indefinite integrals for the Lommel functions, which obey an inhomogeneous Bessel equation. The method allows integrals to be derived for the inhomogeneous equation in a manner which closely parallels the homogeneous case, and a number of new Lommel integrals are derived which have well-known Bessel analogues. Results will be presented separately for other special functions which obey inhomogeneous second-order linear…
A generalized integration formula for indefinite integrals of special functions
2020
An integration formula for generating indefinite integrals which was presented in Conway JT [A Lagrangian method for deriving new indefinite integrals of special functions. Integral Transforms Spec...