982 resultados para Theoretical mathematics


Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this report I present a summary of the three dimensions used in PISA 2003assessment in mathematics: Content, Process and Situation, and I includesome examples of items.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Este artículo presenta los resultados de un estudio sobre las tradiciones de enseñanza en cuatro países europeos: Bélgica (Flandes), Inglaterra, Hungría y España. Se trata de un estudio a pequeña escala en el que se emplean métodos cuantitativos y cualitativos, y que, en lugar de pretender obtener generalizaciones, está orientado a arrojar alguna luz que posibilite la mejora de la enseñanza y el aprendizaje de las matemáticas. Establece comparaciones con los resultados de los test TIMSS y PISA y extrae alguna conclusión para la formación inicial de maestros y profesores de matemáticas. Extraemos de éste los resultados relativos a los datos cuantitativos y nos centramos en el foco matemático.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper we present an analysis of the inductive reasoning of twelve secondary students in a mathematical problem-solving context. Students were proposed to justify what is the result of adding two even numbers. Starting from the theoretical framework, which is based on Pólya’s stages of inductive reasoning, and our empirical work, we created a category system that allowed us to make a qualitative data analysis. We show in this paper some of the results obtained in a previous study.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper, we report some findings from an investigation of a topic related to affect and mathematics which is not well-represented in the literature. For some mathematicians, mathematics itself is a source of security in an uncertain world, and we investigated this feeling and experience in the case of 19 adult mathematicians working in universities and schools in Greece. The focus reported here is on ways that a relationship with mathematics offers a sense of permanence and stability on the one hand, and an assurance of novelty and progress on the other.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Description of some variables used in PISA 2003 project to asses competences.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This study describes the performance of the mentors in a blended graduate-level training program of teachers in the field of secondary school mathematics. We codified and analyzed the mentors’ comments on the projects presented by the groups of in-service teachers for whom they (the mentors) were responsible. To do this, we developed a structure of categories and codes based on a combination of a literature review, a model of teacher learning, and a cyclical review of the data. We performed two types of analysis: frequency and cluster. The first analysis permitted us to characterize the common actions shared by most of the mentors. From the second, we established three profiles of the mentors’ actions.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Probe-based scanning microscopes, such as the STM and the AFM, are used to obtain the topographical and electronic structure maps of material surfaces, and to modify their morphologies on nanoscopic scales. They have generated new areas of research in condensed matter physics and materials science. We will review some examples from the fields of experimental nano-mechanics, nano-electronics and nano-magnetism. These now form the basis of the emerging field of Nano-technology. A parallel development has been brought about in the field of Computational Nano-science, using quantum-mechanical techniques and computer-based numerical modelling, such as the Molecular Dynamics (MD) simulation method. We will report on the simulation of nucleation and growth of nano-phase films on supporting substrates. Furthermore, a theoretical modelling of the formation of STM images of metallic clusters on metallic substrates will also be discussed within the non-equilibrium Keldysh Green function method to study the effects of coherent tunnelling through different atomic orbitals in a tip-sample geometry.

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

On the 19 June 2001, a Thames passenger/tour boat underwent several evacuation trials. This work was conducted in order to collect data for the validation of marine-based computer models. The trials involved 111 participants who were distributed throughout the vessel. The boat had two decks and two points of exit from the lower deck placed on either side of the craft, forward and aft. The boat had a twin set of staircases towards the rear of the craft, just forward of the rear exits. maritimeEXODUS was used to simulate the full-scale evacuation trials conducted. The simulation times generated were compared against the original results and categorised according to the exit point availability. The predictions closely approximate the original results, differing by an average of 6.6% across the comparisons, with numerous qualitative similarities between the predictions and experimental results. The maritimeEXODUS evacuation model was then used to examine the evacuation procedure currently employed on the vessel. This was found to have potential to produce long evacuation times. maritimeEXODUS was used to suggest modifications to the mustering procedures. These theoretical results suggest that it is possible to significantly reduce evacuation times.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper we look at ways of delivering and assessing learning on database units offered on higher degree programmes (MSc) in the School of Computing and Mathematical Sciences at the University of Greenwich. Of critical importance is the teaching methods employed for verbal disposition, practical laboratory exercises and a careful evaluation of assessment methods and assessment tools in view of the fact that databases involve not only database design but also use of practical tools, such as database management systems (DBMSs) software, human designers, database administrators (DBA) and end users. Our goal is to clearly identify potential key success factors in delivering and assessing learning in both practical and theoretical aspects of database course units.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Tony Mann provides a report of a two-day meeting "Magic and mathematics: The life and work of John Dee" held from 13-14 June 2003 at the National Maritime Museum, Greenwich.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Particle concentration is known as a main factor that affects erosion rate of pipe bends in pneumatic conveyors. With consideration of different bend radii, the effect of particle concentration on weight loss of mild steel bends has been investigated in an industrial scale test rig. Experimental results show that there was a significant reduction of the specific erosion rate for high particle concentrations. This reduction was considered to be as a result of the shielding effect during the particle impacts. An empirical model is given. Also a theoretical study of scaling on the shielding effect, and comparisons with some existing models, are presented. It is found that the reduction in specific erosion rate (relative to particle concentration) has a stronger relationship in conveying pipelines than has been found in the erosion tester.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Review of Mathematics and Culture II. Visual Perfection: Mathematics and Creativity, Michele Emmer (Ed.), Springer, 2005 ISBN: 978-3-540-21368-0

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper investigates an isothermal fatigue test for solder joints developed at the NPL. The test specimen is a lap joint between two copper arms. During the test the displacement at the ends of the copper are controlled and the force measured. The modeling results in the paper show that the displacement across the solder joint is not equal to the displacement applied at the end of the specimen. This is due to deformation within the copper arms. A method is described to compensate for this difference. The strain distribution in the solder was determined by finite element analysis and compared to the distribution generated by a theoretical 'ideal' test which generates an almost pure shear mode in the solder. By using a damage-based constitutive law the shape of the crack generated in the specimen has been predicted for both the actual test and the ideal pure shear test. Results from the simulations are also compared with experimental data using SnAgCu solder.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Cold crucible furnace is widely used for melting reactive metals for high quality castings. Although the water cooled copper crucible avoids contamination, it produces a low superheat of the melt. Experimental and theoretical investigations of the process showed that the increase of the supplied power to the furnace leads to a saturation in the temperature rise of the melt, and no significant increase of the melt superheat can be obtained. The computer model of theprocess has been developed to simulate the time dependent turbulent flow, heat transfer with phase change, and AC and DC magnetohydrodynamics in a time varying liquid metal envelope. The model predicts that the supermimposition of a strong DC field on top of the normal AC field reduces the level of turbulience and stirring in the liquid metal, thereby reducing the heat loss through the base of the crucible and increasing the superheat. The direct measurements of the temperature in the commercial size cold crucbile has confirmed the computer redictions and showed that the addition of a DC field increased the superheat in molten TiAl from ~45C (AC field only) to ~81C (DC+AC fields). The present paper reports further predictions of the effect of a dDC field on top of the AC field and compares these with experimental data.