Search results for "Mathematic"
showing 10 items of 24974 documents
The Joint Distribution Criterion and the Distance Tests for Selective Probabilistic Causality
2010
A general definition and a criterion (a necessary and sufficient condition) are formulated for an arbitrary set of external factors to selectively influence a corresponding set of random entities (generalized random variables, with values in arbitrary observation spaces), jointly distributed at every treatment (a set of factor values containing precisely one value of each factor). The random entities are selectively influenced by the corresponding factors if and only if the following condition, called the joint distribution criterion, is satisfied : there is a jointly distributed set of random entities, one entity for every value of every factor, such that every subset of this set that corr…
Stress sensitivity of stylolite morphology
2009
International audience; Stylolites are rough surfaces that form by localized stress-induced dissolution. Using a set of limestone rock samples collected at different depths from a vertical section in Cirque de Navacelles (France), we study the influence of the lithostatic stress on the stylolites morphology on the basis of a recent morphogenesis model. We measured the roughness of a series of bedding-parallel stylolites and show that their morphology exhibits a scaling invariance with two self-affine scaling regimes separated by a crossover-length (L) at the millimeter scale consistent with previous studies. The importance of the present contribution is to estimate the stylolite formation s…
A black-box, general purpose quadratic self-consistent field code with and without Cholesky Decomposition of the two-electron integrals
2021
We present the implementation of a quadratically convergent self-consistent field (QCSCF) algorithm based on an adaptive trust-radius optimisation scheme for restricted open-shell Hartree���Fock (ROHF), restricted Hartree���Fock (RHF), and unrestricted Hartree���Fock (UHF) references. The algorithm can exploit Cholesky decomposition (CD) of the two-electron integrals to allow calculations on larger systems. The most important feature of the QCSCF code lies in its black-box nature ��� probably the most important quality desired by a generic user. As shown for pilot applications, it does not require one to tune the self-consistent field (SCF) parameters (damping, Pulay's DIIS, and other simil…
Diseño de un sistema de apoyo a la regulación social del aprendizaje en los xMOOC
2019
Esta investigación tiene como objetivo estudiar los procesos de regulación del aprendizaje, atendiendo tanto a su dimensión individual como social, en entornos de xMOOC. En concreto, se propone analizar cómo los procesos de autorregulación, corregulación y regulación social compartida pueden apoyarse y promoverse en este tipo de contextos abiertos y masivos para conseguir un aprendizaje más profundo. Para ello, se aplica un modelo de investigación basada en el diseño que permite intervenir directamente en la práctica pedagógica, a través de un proceso cíclico de cuatro etapas: diseño, intervención, evaluación y reflexión y rediseño de un sistema de apoyo a la regulación del aprendizaje en u…
Comparing male and female students’ self-efficacy and self-regulation skills in two undergraduate mathematics course contexts
2018
International audience; Students' efficacy beliefs have a positive influence on students' academic achievement and retention, especially for female students. These beliefs are closely linked to students' ability to regulate their learning. In this quantitative study, students' self-efficacy and self-regulation of learning are compared in two university mathematics courses that differ in content but also in their pedagogical setting: one is a more traditional lecture-based course, and the other course is taught with the Extreme Apprenticeship (XA) method. The analysis is based on the same cohort of students in the two contexts (N=91). The results suggest that students have higher self-effica…
High precision numerical approach for Davey–Stewartson II type equations for Schwartz class initial data
2020
We present an efficient high-precision numerical approach for Davey–Stewartson (DS) II type equa- tions, treating initial data from the Schwartz class of smooth, rapidly decreasing functions. As with previous approaches, the presented code uses discrete Fourier transforms for the spatial dependence and Driscoll’s composite Runge–Kutta method for the time dependence. Since DS equations are non-local, nonlinear Schrödinger equations with a singular symbol for the non-locality, standard Fourier methods in practice only reach accuracy of the order of 10−6or less for typical examples. This was previously demonstrated for the defocusing integrable case by comparison with a numerical approach for …
Análisis de los antecedentes histórico-filosóficos de la "paradoja cognitiva de Duval"
2015
In a famous article published in 1993, Raymond Duval highlighted a simple fact: the student may confuse the mathematical object O he is trying to build cognitively with one of its semiotic representations R(O). Duval explained that this confusion was due to a sort of inevitable paradox: only someone who has already built O, can recognize R(O) as a representation of O and not as an object in itself. Thereafter, this thought has been extremely influential for researchers. However, even if in different terms, many scholars of semiotics have emphasized the same phenomenon. In this paper we propose to remind some of them. En un famoso artículo publicado en 1993, Raymond Duval evidenciaba el sigu…
Some Investigations on Similarity Measures Based on Absent Words
2019
In this paper we investigate similarity measures based on minimal absent words, introduced by Chairungsee and Crochemore in [1]. They make use of a length-weighted index on a sample set corresponding to the symmetric difference M(x)ΔM(y) of the minimal absent words M(x) and M(y) of two sequences x and y, respectively. We first propose a variant of this measure by choosing as a sample set a proper subset (x, y) of M(x)ΔM(y), which appears to be more appropriate for distinguishing x and y. From the algebraic point of view, we prove that (x, y) is the base of the ideal generated by M(x)ΔM(y). We then remark that such measures are able to recognize whether the sequences x and y share a common s…
Players' progression through GraphoGame, an early literacy game: Influence of game design and context of play
2019
Researchers of serious games frequently investigate outcomes of play but overlook the underlying game-design components that drive those outcomes. In this paper, I aim to show how game design and context of play influence progression through GraphoGame, an early-literacy game. This is done by means of two intersecting studies. The first study shows how the game can be represented by a model that explicitly hypothesizes how the interaction between the player and the game drives progression. The second study explores user data generated by first graders (N = 137) who played the game over a period of 25 weeks as part of early literacy instruction. The juxtaposition of these two studies reveals…
Lebesgue-type decomposition for sesquilinear forms via differences
2022
Definitions of regularity and singularity are proposed for sesquilinear forms with respect to a non-negative one and a correspondent Lebesgue-type decomposition is proved. In contrast to other Lebesgue-type decompositions established in the literature for sesquilinear forms with generic sign, the underlying idea in this paper is to write symmetric forms as the difference of non-negative sesquilinear forms.