Search results for "Mathematica"
showing 10 items of 7971 documents
Designing Playful Inquiry-Based Mathematical Learning Activities for Kindergarten
2018
This study addresses issues related to the process of designing mathematical activities for kindergarten based on the constructs of playful learning and inquiry. The mathematical activities were designed for 5-year-old children in a Norwegian kindergarten setting. In order to address this design process, we focus at issues of mediating design principles and ideas to kindergarten teachers, who are the ones to orchestrate and implement the mathematical activities with children. The study is situated within a design research methodology in which observations, written and personal communication have been used as sources of data. Our analysis shows that the kindergarten teacher closely followed …
Epidemiology and Reporting Characteristics of Systematic Reviews of Biomedical Research: A Cross-Sectional Study.
2016
Background Systematic reviews (SRs) can help decision makers interpret the deluge of published biomedical literature. However, a SR may be of limited use if the methods used to conduct the SR are flawed, and reporting of the SR is incomplete. To our knowledge, since 2004 there has been no cross-sectional study of the prevalence, focus, and completeness of reporting of SRs across different specialties. Therefore, the aim of our study was to investigate the epidemiological and reporting characteristics of a more recent cross-section of SRs. Methods and Findings We searched MEDLINE to identify potentially eligible SRs indexed during the month of February 2014. Citations were screened using pre…
Kindergarten teachers’ orchestration of mathematical activities afforded by technology: agency and mediation
2016
This paper focuses on kindergarten teachers’ interactions with young children during mathematical learning activities involving the use of digital tools. We aim to characterise the teachers’ roles and actions in these activities and extend considerations of teachers’ orchestrations current in the research literature with regard to agency and mediation. Our analysis of teacher-children-digital tool interaction reveals that the kindergarten teachers took three roles in their work with young children, which we call Assistant, Mediator and Teacher roles. These roles were used interchangeably and purposefully by the kindergarten teachers. With regard to agency and mediation, we argue that agency…
Heuristics and Memory Strategies Used by Mathematicians
1996
The study of the cognitive processes involved in learning and acquisition of technically complex material is a main focus of interest for basic and applied research. Our research program tries to identh memory aids and heuristic training strategies useful for improving mathematics performance. Part of the effectiveness of a course, designed by taking into account knowledge about the cognitive system, has to do with the development of an adequate relationship with the belief system of the learner. As a first step in that direction, we present a survey of the opinions of a group of mathematicians about the dd€iculty of their subjecr matter, the strategies they use spontaneously to overcome di…
Online pricing for demand-side management in a low-voltage resistive micro-grid via a Stackelberg game with incentive strategies
2022
It has been demonstrated that online pricing mechanisms are a viable solution for demand side management in power systems. This study deals with the analysis and design of a droop-controlled low-voltage resistive AC micro-grid network system. Such a system is subjected to a dynamic demand obtained from an online pricing mechanism, which is proposed as a novelty in the study of micro-grids. This mechanism is derived from a variation of the Stackelberg game, which includes the use of incentive strategies. First, a configuration in which a supplier announces an incentive function and (Formula presented.) -consumers’ reaction to the resulting personalised price is presented. Then, a detailed st…
An Empirical Mode Decomposition Approach to Assess the Strength of Heart Period-Systolic Arterial Pressure Variability Interactions.
2020
This work proposes an empirical mode decomposition (EMD) method to assess the strength of the interactions between heart period (HP) and systolic arterial pressure (SAP) variability. EMD was exploited to decompose the original series (OR) into its first, and fastest, intrinsic mode function (IMF1) and the residual (RES) computed by subtracting the IMF1 from OR. EMD procedure was applied to both HP and SAP variability series. Then, the cross correlation function (CCF) was computed over OR, IMF1 and RES series derived from HP and SAP variability in 13 healthy subjects (age 27±8 yrs, 5 males) at rest in supine position (REST) and during head-up tilt (TILT). The first CCF maximum at negative ti…
Well-Balanced Adaptive Mesh Refinement for shallow water flows
2014
Well-balanced shock capturing (WBSC) schemes constitute nowadays the state of the art in the numerical simulation of shallow water flows. They allow to accurately represent discontinuous behavior, known to occur due to the non-linear hyperbolic nature of the shallow water system, and, at the same time, numerically maintain stationary solutions. In situations of practical interest, these schemes often need to be combined with some kind of adaptivity, in order to speed up computing times. In this paper we discuss what ingredients need to be modified in a block-structured AMR technique in order to ensure that, when combined with a WBSC scheme, the so-called 'water at rest' stationary solutions…
Domain walls and ising-BLOCH transitions in parametrically driven systems.
2002
Parametrically driven systems sustaining sech solitons are shown to support a new kind of localized state. These structures are walls connecting two regions oscillating in antiphase that form in the parameter domain where the sech soliton is unstable. Depending on the parameter set the oppositely phased domains can be either spatially uniform or patterned. Both chiral (Bloch) and nonchiral (Ising) walls are found, which bifurcate one into the other via an Ising-Bloch transition. While Ising walls are at rest Bloch walls move and may display secondary bifurcations leading to chaotic wall motion.
Numerical Front Propagation Using Kinematical Conservation Laws
2011
We use the newly formulated three-dimensional (3-D) kinematical conservation laws (KCL) to study the propagation of a nonlinear wavefront in a polytropic gas in a uniform state at rest. The 3-D KCL forms an under-determined system of six conservation laws with three involutive constraints, to which we add the energy conservation equation of a weakly nonlinear ray theory. The resulting system of seven conservation laws is only weakly hyperbolic and therefore poses a real challenge in the numerical approximation. We implement a central finite volume scheme with a constrained transport technique for the numerical solution of the system of conservation laws. The results of a numerical experimen…
Adiabatic evolution for systems with infinitely many eigenvalue crossings
1998
International audience; We formulate an adiabatic theorem adapted to models that present an instantaneous eigenvalue experiencing an infinite number of crossings with the rest of the spectrum. We give an upper bound on the leading correction terms with respect to the adiabatic limit. The result requires only differentiability of the considered projector, and some geometric hypothesis on the local behavior of the eigenvalues at the crossings.