Intrasubject repeatability in keratoconus-eye measurements obtained with a new Scheimpflug photography–based system

Purpose: To evaluate in keratoconus eyes the intrasubject repeatability of anterior and posterior corneal curvature and of other anterior segment anatomic measurements obtained with a new topography system combining Scheimpflug-photography and Placido-disk technology. Setting: Vissum Corporation, Alicante, Spain. Design: Evaluation of technology. Methods: All keratoconus eyes had a comprehensive ophthalmologic examination including analysis with the Sirius system. Three consecutive measurements were obtained to assess the intrasubject repeatability of the following parameters: anterior and posterior corneal curvature and shape factor, white-to-white (WTW) corneal diameter, central and minimum corneal thickness, and anterior chamber depth (ACD). The within-subject standard deviation (Sw) and intraclass correlation coefficient (ICC) were calculated. Results: This study comprised 61 eyes of 61 patients ranging in age from 14 to 64 years. For anterior and posterior corneal curvatures and power vector components, the Sw was 0.29 mm or less in all cases. The ICC was above 0.990 in all cases except the flattest curvature of the posterior corneal surface at 3.0 mm, which was 0.840 (moderate agreement), and the posterior power vector J0, which was 0.665 (poor agreement), 0.752, and 0.758 (moderate agreement) for 3.0 mm, 5.0 mm, and 7.0 mm, respectively. In shape factor measurements, the Sw was 0.12 or less in all cases and the ICC ranged between 0.989 and 0.999. Pachymetry, ACD, and WTW had ICC values very close to 1. Conclusion: The new topography system provided repeatable measurements of corneal shape and other anatomic parameters in eyes with keratoconus.

A Performance Evaluation of Surface Normals-Based Descriptors for Recognition of Objects using CAD-Models

This paper describes a study and analysis of surface normal-base descriptors for 3D object recognition. Specifically, we evaluate the behaviour of descriptors in the recognition process using virtual models of objects created from CAD software. Later, we test them in real scenes using synthetic objects created with a 3D printer from the virtual models. In both cases, the same virtual models are used on the matching process to find similarity. The difference between both experiments is in the type of views used in the tests. Our analysis evaluates three subjects: the effectiveness of 3D descriptors depending on the viewpoint of camera, the geometry complexity of the model and the runtime used to do the recognition process and the success rate to recognize a view of object among the models saved in the database.

Stability in Linear Optimization Under Perturbations of the Left-Hand Side Coefficients

This paper studies stability properties of linear optimization problems with finitely many variables and an arbitrary number of constraints, when only left hand side coefficients can be perturbed. The coefficients of the constraints are assumed to be continuous functions with respect to an index which ranges on certain compact Hausdorff topological space, and these properties are preserved by the admissible perturbations. More in detail, the paper analyzes the continuity properties of the feasible set, the optimal set and the optimal value, as well as the preservation of desirable properties (boundedness, uniqueness) of the feasible and of the optimal sets, under sufficiently small perturbations.

La lingüística a través del humor: aplicaciones didácticas

Las investigaciones que hemos llevado a cabo en el marco del grupo GRIALE (Proyecto I+D “Innovaciones lingüísticas del humor: géneros textuales, identidad y enseñanza del español” (FFI2012-30941), así como en una Red docente anterior (2774 “Humor y perspectiva de género: análisis y aplicaciones didácticas”, 2012-2013) nos han conducido a plantear esta nueva tarea docente (Red 3161: “La lingüística a través del humor: aplicaciones didácticas”) que se centra en la elaboración de propuestas metodológicas sobre el uso del humor como herramienta de optimización en la presentación de contenidos teóricos de las asignaturas de lingüística y de lenguas en los diversos grados de Filología y de Traducción. En efecto, el formato de discurso humorístico proporciona un marco ideal para crear instrumentos didácticos que conviertan en atractivos los contenidos de materias lingüísticas que a menudo resultan difíciles por su alto nivel de abstracción. Creemos que nuestro enfoque puede contribuir al aumento de la motivación del alumnado y facilitar el proceso de asimilación de la información. Asimismo, otro aspecto clave, como es la formación de la competencia metalingüística, recibe nuestra atención dado que el desentrañamiento de los patrones lingüísticos del humor constituye una tarea altamente reflexiva y resulta útil de cara al ejercicio profesional de los futuros filólogos y traductores.