Search results for "MATHEMATICS"
showing 10 items of 22031 documents
The Journal de Math\'ematiques Pures et Appliqu\'ees(1917-1937) : correspondence between Henri Villat and Robert de Montessus de Ballore
2014
We are interested in the "Journal de Math\'ematiques Pures et Appliqu\'ees" (JMPA) over the period 1917-1937. From the end of 1921, two mathematicians worked to its publication, Henri Villat as editor in chief and Robert Montessus Ballore as associate editor. Through unpublished letters, we descrive the operation of the JMPA.
Helping lecturers address and formulate teaching challenges: an exploratory study
2018
International audience; In this paper we present an exploratory study on the kind of questions or difficulties lecturers point out at the beginning of an educational course – to be addressed in it. These questions happen to be very general and are poorly connected to the knowledge to be taught. We suggest a twofold interpretation of this phenomenon. On the one hand, and in the line of the didactic transposition theory, teachers do not allow themselves to raise questions about the knowledge that is supposed to be their main field of expertise. On the other hand, the prevailing institutional pedagogy does not provide teachers with a fruitful enough conceptual frame to formulate this kind of q…
Preliminary photochemical studies of fluorene in various aqueous media
2014
- The current study investigates the direct photochemical degradation of aqueous fluorene with the aid of a 125W polychromatic medium, pressure Hg lamp. The purpose was to test the effectiveness of the lamp in irradiation using fluorene spiked solution as substrate. A 700 ml volume of fluorene solution of 0.002 mg/l was irradiated batch-wise at 1, 3, 6, 12, 18, 24 and 48 h. The amount of fluorene removal was studied for fluorene solutions prepared from , neutral (distilled water), acidic (by adjusting pH with hydrochloric acid, HCl), basic (by adjusting pH with sodium hydroxide, NaOH) and saline (addition of sodium chloride, NaCl) solutions and there was 95.95, 92.35, 96.65 and 97.15 % remo…
A Viscoelastic Model for the Long-Term Deflection of Segmental Prestressed Box Girders
2017
Most of segmental prestressed concrete box girders exhibit excessive multidecade deflections unforeseeable by past and current design codes. To investigate such a behavior, mainly caused by creep and shrinkage phenomena, an effective finite element (FE) formulation is presented in this article. This formulation is developed by invoking the stationarity of an energetic principle for linear viscoelastic problems and relies on the Bazant creep constitutive law. A case study representative of segmental prestressed concrete box girders susceptible to creep is also analyzed in the article, that is, the Colle Isarco viaduct. Its FE model, based on the aforementioned energetic formulation, was succ…
Real Algebraic Geometry
2011
144 Pages; Cet ouvrage constitue les actes de la conférence de Géométrie Algébrique Réelle qui a eu lieu à Rennes du 20 au 24 Juin 2011
Initial strain effects in multilayer composite laminates
2001
A boundary integral formulation for the analysis of stress fields induced in composite laminates by initial strains, such as may be due to temperature changes and moisture absorption is presented. The study is formulated on the basis of the theory of generalized orthotropic thermo-elasticity and the governing integral equations are directly deduced through the generalized reciprocity theorem. A suitable expression of the problem fundamental solutions is given for use in computations. The resulting linear system of algebraic equations is obtained by the boundary element method and stress interlaminar distributions in the boundary-layer are calculated by using a boundary only discretization. …
High-statistics study of f0(1500) decay into π0π0
1995
Abstract A partial-wave analysis of the reaction p p →π 0 π 0 π 0 has been performed using a high-quality high-statistics data set of 712 000 events. In addition to the f0(975) and f0(1300), the scalar resonance with mass m = (1500 ± 15) MeV and width Γ = (120 ± 25) MeV is necessary to describe the data.
Forecasting correlated time series with exponential smoothing models
2011
Abstract This paper presents the Bayesian analysis of a general multivariate exponential smoothing model that allows us to forecast time series jointly, subject to correlated random disturbances. The general multivariate model, which can be formulated as a seemingly unrelated regression model, includes the previously studied homogeneous multivariate Holt-Winters’ model as a special case when all of the univariate series share a common structure. MCMC simulation techniques are required in order to approach the non-analytically tractable posterior distribution of the model parameters. The predictive distribution is then estimated using Monte Carlo integration. A Bayesian model selection crite…
Summary of Trap Properties
2009
Three-dimensional confinement of charged particles requires a potential energy minimum at some region in space, in order that the corresponding force is directed toward that region in all three dimensions. In general, the dependence of the magnitude of this force on the coordinates can have an arbitrary form; however, it is convenient to have a binding force that is harmonic, since this simplifies the analytical description of the particle motion.
Value, satisfaction and loyalty in volunteerism. Application to a religious megaevent
2013
This paper presents a study of the volunteer as an essential agent in the success of any event, and offers recommendations for improving management of megaevents. To achieve this goal we propose a structural model that analyses the multidimensionality of the value concept as antecedent of perceived value, satisfaction and loyalty. The study sample consists of volunteers who participated in the World Youth Day held in Madrid in 2011, obtaining a total number of 1427 cases. The results support all the hypotheses presented in the proposed model. Thus, it confirms that the multidimensionality of the value (spirituality, social value, play and efficiency) is an antecedent of perceived value whil…