Search results for "theory [gamma rays]"
showing 10 items of 976 documents
Prediction of the difficulty level in a standardized reading comprehension test: contributions from cognitive psychology and psychometrics
2013
This research seeks to identify possible predictors of the difficulty level of reading comprehension items used in a standardized psychometric test for university admission. Several potential predictors of difficulty were proposed, namely, propositional density, negations, grammatical structure, vocabulary difficulty, presence of enhancement elements (words highlighted typographically), item abstraction level and degree of similarity between correct option and relevant text to resolve the item. By Linear Logistic Test Model (Fisher, 1973) it was found that the number of propositions, the syntactic structure, and fundamentally, the presence of difficult words contributed to the prediction of…
La voz del estudiante en la evaluación del aprendizaje: un camino por recorrer en la universidad
2012
During 2009/2010, the current research was conducted with the aim of analysing student and teaching staff on regarding student participation in assessment. A content analysis of 76 subject outlines was carried out, and then 40 member of the teaching staff and 614 university students were surveyed. The results of the content analysis prove there is a shortage of information about and programming for student participation in assessment. Durante el curso 2009/2010 se llevó a cabo esta investigación con el objetivo de analizar la opinión y perspectiva que profesores y estudiantes universitarios tienen sobre la participación de estos últimos en el proceso de evaluación. Se realizó un análisis de…
Swarming Models for Facilitating Collaborative Decisions
2010
The paper highlights the computational power of swarming models (i.e., stigmergic mechanisms) to build collaborative support systems for complex cognitive tasks such as facilitation of group decision processes (GDP) in e-meetings. Unlike traditional approaches that minimize the cognitive complexity by incorporating the facilitation knowledge into the system, stigmergic coordination mechanisms minimize the complexity by providing the system with emergent functionalities that are shaped by the environment itself through the possibility to structure it in terms of high-level cognitive artefacts. This is illustrated by conducting a socio-simulation experiment for an envisioned collaborative sof…
A comparison analysis between unsymmetric and symmetric radial basis function collocation methods for the numerical solution of partial differential …
2002
Abstract In this article, we present a thorough numerical comparison between unsymmetric and symmetric radial basis function collocation methods for the numerical solution of boundary value problems for partial differential equations. A series of test examples was solved with these two schemes, different problems with different type of governing equations, and boundary conditions. Particular emphasis was paid to the ability of these schemes to solve the steady-state convection-diffusion equation at high values of the Peclet number. From the examples tested in this work, it was observed that the system of algebraic equations obtained with the symmetric method was in general simpler to solve …
Commuting powers and exterior degree of finite groups
2011
In [P. Niroomand, R. Rezaei, On the exterior degree of finite groups, Comm. Algebra 39 (2011), 335-343] it is introduced a group invariant, related to the number of elements $x$ and $y$ of a finite group $G$, such that $x \wedge y = 1_{G \wedge G}$ in the exterior square $G \wedge G$ of $G$. This number gives restrictions on the Schur multiplier of $G$ and, consequently, large classes of groups can be described. In the present paper we generalize the previous investigations on the topic, focusing on the number of elements of the form $h^m \wedge k$ of $H \wedge K$ such that $h^m \wedge k = 1_{H \wedge K}$, where $m \ge 1$ and $H$ and $K$ are arbitrary subgroups of $G$.
Towards Vorst's conjecture in positive characteristic
2018
Vorst's conjecture relates the regularity of a ring with the $\mathbb{A}^1$-homotopy invariance of its $K$-theory. We show a variant of this conjecture in positive characteristic.
Learning with belief levels
2008
AbstractWe study learning of predicate logics formulas from “elementary facts,” i.e. from the values of the predicates in the given model. Several models of learning are considered, but most of our attention is paid to learning with belief levels. We propose an axiom system which describes what we consider to be a human scientist's natural behavior when trying to explore these elementary facts. It is proved that no such system can be complete. However we believe that our axiom system is “practically” complete. Theorems presented in the paper in some sense confirm our hypothesis.
Computation of Yvon-Villarceau circles on Dupin cyclides and construction of circular edge right triangles on tori and Dupin cyclides
2014
Ring Dupin cyclides are non-spherical algebraic surfaces of degree four that can be defined as the image by inversion of a ring torus. They are interesting in geometric modeling because: (1) they have several families of circles embedded on them: parallel, meridian, and Yvon-Villarceau circles, and (2) they are characterized by one parametric equation and two equivalent implicit ones, allowing for better flexibility and easiness of use by adopting one representation or the other, according to the best suitability for a particular application. These facts motivate the construction of circular edge triangles lying on Dupin cyclides and exhibiting the aforementioned properties. Our first contr…
Topology-based goodness-of-fit tests for sliced spatial data
2023
In materials science and many other application domains, 3D information can often only be extrapolated by taking 2D slices. In topological data analysis, persistence vineyards have emerged as a powerful tool to take into account topological features stretching over several slices. In the present paper, we illustrate how persistence vineyards can be used to design rigorous statistical hypothesis tests for 3D microstructure models based on data from 2D slices. More precisely, by establishing the asymptotic normality of suitable longitudinal and cross-sectional summary statistics, we devise goodness-of-fit tests that become asymptotically exact in large sampling windows. We illustrate the test…