Search results for "direct method"
showing 10 items of 51 documents
Le manuel Corso di Lingua francese a base intuitiva de Romeo Lovera
2020
We analyze the three volumes of Romeo Lovera’s manual, Corso di Lingua francese a base intuitiva, which were intended for teaching French in secondary schools. The manual was first published in 1902 in Venice by Libreria editrice del Bollettino di Filologia Moderna, and there will be many reissues. Romeo Lovera is Italy's biggest supporter of methodological reform in the teaching of foreign languages ; it discloses, through the Bollettino di Filologia Moderna, new theories, scientific methods and their didactic applications. In their manuals, from the first lesson, through the direct and indirect intuition of the foreign language, the student learns to speak the French language by studying …
A new interpretation and practical aspects of the direct-methods modulus sum function. VIII
2001
Since the first publication of the direct-methods modulus sum function [Rius (1993). Acta Cryst. A49, 406-409], the application of this function to a variety of situations has been shown in a series of seven subsequent papers. In this way, much experience about this function and its practical use has been gained. It is thought by the authors that it is now the right moment to publish a more complete study of this function which also considers most of this practical knowledge. The first part of the study relates, thanks to a new interpretation, this function to other existing phase-refinement functions, while the second shows, with the help of test calculations on a selection of crystal stru…
Nondestructive Direct Determination of Heroin in Seized Illicit Street Drugs by Diffuse Reflectance near-Infrared Spectroscopy
2008
A new method has been developed for the fast and nondestructive direct determination of heroin in seized street illicit drugs using partial least-squares regression analysis of diffuse reflectance near-infrared spectra. Data were obtained from untreated samples placed in standard glass chromatography vials. A heterogeneous population of 31 samples, previously analyzed by a reference method, was employed to build the calibration model and to have a separated validation set. Based on the use of zero-order data for a calibration set of 21 samples, after standard normal variate and quadratic linear removed baseline correction (detrending), in the wavelength range from 1111 to 1647 nm, 8 PLS fac…
An adaptive method for Volterra–Fredholm integral equations on the half line
2009
AbstractIn this paper we develop a direct quadrature method for solving Volterra–Fredholm integral equations on an unbounded spatial domain. These problems, when related to some important physical and biological phenomena, are characterized by kernels that present variable peaks along space. The method we propose is adaptive in the sense that the number of spatial nodes of the quadrature formula varies with the position of the peaks. The convergence of the method is studied and its performances are illustrated by means of a few significative examples. The parallel algorithm which implements the method and its performances are described.
A combination of algebraic, geometric and numerical methods in the contrast problem by saturation in magnetic resonance imaging
2014
In this article, the contrast imaging problem by saturation in nuclear magnetic resonance is modeled as a Mayer problem in optimal control. The optimal solution can be found as an extremal solution of the Maximum Principle and analyzed with the recent advanced techniques of geometric optimal control. This leads to a numerical investigation based on shooting and continuation methods implemented in the HamPath software. The results are compared with a direct approach to the optimization problem and implemented within the Bocop toolbox. In complement lmi techniques are used to estimate a global optimum. It is completed with the analysis of the saturation problem of an ensemble of spin particle…
Direct monitoring of spin state in dinuclear iron(II) coordination compounds
2001
So far there has been no direct method to determine the spin state of molecules in dinuclear iron(II) compounds. The molecular fractions of high-spin (HS) and low-spin (LS) species have been deduced from magnetic susceptibility and zero-field Mossbauer spectroscopy data irrespective of whether they belong to LS–LS, LS–HS and HS–HS pairs. However, the distinction of pairs becomes possible if Mossbauer measurements are carried out in an external magnetic field. The proposed method opens new possibilities in the study of spin crossover phenomena in dinuclear compounds.
The beta-delayed proton and gamma decay of 27P for nuclear astrophysics
2013
The creation site of 26Al is still under debate. It is thought to be produced in hydrogen burning and in explosive helium burning in novae and supernovae, and possibly also in the H-burning in outer shells of red giant stars. Also, the reactions for its creation or destruction are not completely known. When 26Al is created in novae, the reaction chain is: 24Mg(p, γ) 25Al(β +ν) 25Mg(p, γ) 26Al, but this chain can be by-passed by another chain, 25Al(p, γ) 26Si(p, γ) 27P and it can also be destroyed directly. The reaction 26mAl(p, γ) 27Si∗ is another avenue to bypass the production of 26Al and it is dominated by resonant capture. We find and study these resonances by an indirect method, throug…
A Stieltjes Approach to Static Hedges
2014
Static hedging of complicated payoff structures by standard instruments becomes increasingly popular in finance. The classical approach is developed for quite regular functions, while for less regular cases, generalized functions and approximation arguments are used. In this note, we discuss the regularity conditions in the classical decomposition formula due to P. Carr and D. Madan (in Jarrow ed, Volatility, pp. 417–427, Risk Publ., London, 1998) if the integrals in this formula are interpreted as Lebesgue integrals with respect to the Lebesgue measure. Furthermore, we show that if we replace these integrals by Lebesgue–Stieltjes integrals, the family of representable functions can be exte…
Exact extension of the DIRECT algorithm to multiple objectives
2019
The direct algorithm has been recognized as an efficient global optimization method which has few requirements of regularity and has proven to be globally convergent in general cases. direct has been an inspiration or has been used as a component for many multiobjective optimization algorithms. We propose an exact and as genuine as possible extension of the direct method for multiple objectives, providing a proof of global convergence (i.e., a guarantee that in an infinite time the algorithm becomes everywhere dense). We test the efficiency of the algorithm on a nonlinear and nonconvex vector function. peerReviewed
A CRITICAL STUDY CONCERNING THE PREPARATION OF THE STATEMENT OF CASH FLOWS THROUGH THE INDIRECT METHOD IN ROMANIA
2012
Although not bound by law, by option, small and medium entities from Romania can prepare the statement for the modifications within their equity and / or the statement of cash flows. When companies select this option, any decision made by the consumer of accounting information is better founded, from the perspective of information sources that it uses, rather than the opposite, because the users of accounting information about a company are almost always interested by the way in which the company generates and uses cash and cash equivalents. In this paper we present the particularities implied in Romania by the preparation of the statement of cash flows using the indirect method.