Search results for " Method."
showing 10 items of 10241 documents
Automorphisms of 2–dimensional right-angled Artin groups
2007
We study the outer automorphism group of a right-angled Artin group AA in the case where the defining graph A is connected and triangle-free. We give an algebraic description of Out.AA/ in terms of maximal join subgraphs in A and prove that the Tits’ alternative holds for Out.AA/. We construct an analogue of outer space for Out.AA/ and prove that it is finite dimensional, contractible, and has a proper action of Out.AA/. We show that Out.AA/ has finite virtual cohomological dimension, give upper and lower bounds on this dimension and construct a spine for outer space realizing the most general upper bound. 20F36; 20F65, 20F28
Menstrual problems and lifestyle among Spanish university women
2020
Menstrual problems affect many young women worldwide, conditioning both their academic performance and quality of life. This study sought to analyse the prevalence of menstrual problems and their possible relationship with lifestyle among Spanish university women, as part of a research project (UniHcos Project) involving a cohort of 11 Spanish universities with 7208 university students. A descriptive analysis was performed using the bivariate chi-square test and the Student&rsquo
Population of lead isotopes in binary reactions using a Rb 94 radioactive beam
2020
8 pags., 9 figs.
Nanomechanics of individual aerographite tetrapods
2017
Carbon-based three-dimensional aerographite networks, built from interconnected hollow tubular tetrapods of multilayer graphene, are ultra-lightweight materials recently discovered and ideal for advanced multifunctional applications. In order to predict the bulk mechanical behaviour of networks it is very important to understand the mechanics of their individual building blocks. Here we characterize the mechanical response of single aerographite tetrapods via in situ scanning electron and atomic force microscopy measurements. To understand the acquired results, which show that the overall behaviour of the tetrapod is governed by the buckling of the central joint, a mechanical nonlinear mode…
A Guide to Perform 3D Histology of Biological Tissues with Fluorescence Microscopy
2023
The analysis of histological alterations in all types of tissue is of primary importance in pathology for highly accurate and robust diagnosis. Recent advances in tissue clearing and fluorescence microscopy made the study of the anatomy of biological tissue possible in three dimensions. The combination of these techniques with classical hematoxylin and eosin (H&E) staining has led to the birth of three-dimensional (3D) histology. Here, we present an overview of the state-of-the-art methods, highlighting the optimal combinations of different clearing methods and advanced fluorescence microscopy techniques for the investigation of all types of biological tissues. We employed fluorescence …
UAV and GPR Data Integration in Glacier Geometry Reconstruction: A Case Study from Irenebreen, Svalbard
2022
Although measurements of thickness and internal structure of glaciers are substantial for the understanding of their evolution and response to climate change, detailed data about polythermal glaciers, are scarce. Here, we present the first ground-penetrating radar (GPR) measurement data of Irenebreen, and high-resolution DEM and orthomosaic, obtained from unmanned aerial vehicle (UAV) photogrammetry. A combination of GPR and UAV data allowed for the reconstruction of the glacier geometry including thermal structure. We compare different methods of GPR signal propagation speed determination and argue that a common midpoint method (CMP) should be used if possible. Our observations reveal that…
Non-convex power allocation games in MIMO cognitive radio networks
2013
Consideramos un escenario de reparto del espectro, basado en la detección, en una red de radio cognitiva MIMO donde el objetivo general es maximizar el rendimiento total de cada usuario de radio cognitiva optimizando conjuntamente la operación de detección y la asignación de potencia en todos los canales, bajo una restricción de interferencia para los usuarios primarios. Los problemas de optimización resultantes conducen a un juego no convexo, que presenta un nuevo desafío a la hora de analizar los equilibrios de este juego. Con el fin de hacer frente a la no convexidad del juego, utilizamos un nuevo concepto relajado de equilibrio, el equilibrio cuasi-Nash (QNE). Se demuestran las condicio…
Non-symmetrized Hyperspherical Harmonics Method for Non-equal Mass Three-Body Systems
2018
The non-symmetrized hyperspherical harmonics method for a three-body system, composed by two particles having equal masses, but different from the mass of the third particle, is reviewed and applied to the $^3$H, $^3$He nuclei and $^3_{\Lambda}$H hyper-nucleus, seen respectively as $nnp$, $ppn$ and $NN\Lambda$ three-body systems. The convergence of the method is first tested in order to estimate its accuracy. Then, the difference of binding energy between $^3$H and $^3$He due to the difference of the proton and the neutron masses is studied using several central spin-independent and spin-dependent potentials. Finally, the $^3_{\Lambda}$H hypernucleus binding energy is calculated using diffe…
Polyphony in the classroom: reporting narrative action research reflexively
2010
In this article we will present a reflexive way of producing a narrative analysis on teaching and learning that involves all participants of the pedagogical process. Our theoretical contribution rests on the concept ‘lived pedagogy’, adapted from Max van Manen's term ‘lived experience’. Like van Manen, we start by asking the key question of phenomenological–hermeneutical research: what is the nature of the phenomenon as meaningfully experienced? For us, the phenomenon is the pedagogical relationship; the interaction between the people involved in the pedagogical process. Thus, we will present how lived pedagogy is researched through the narratives told by the teacher‐researcher, the student…
Case study on teachers’ contribution to children’s participation in Finnish preschool classrooms during structured learning sessions
2013
The main aim of this study was to identify different teaching practices and explore the types of opportunities that they provide for children’s participation in four different Finnish preschool classrooms for 6-year olds during structured learning sessions. Observational data of four preschool teachers were analyzed according to the principles of qualitative content analysis. Three themes of teachers’ practices were identified, which described the key practices through which teachers influence children’s participation, namely, through discussion and conversations; by referring to shared rules and managing the classroom; and through demonstrating pedagogical sensitivity and understanding tow…