3D-based reconstruction using growing neural gas landmark: application to rapid prototyping in shoe last manufacturing

Customizing shoe manufacturing is one of the great challenges in the footwear industry. It is a production model change where design adopts not only the main role, but also the main bottleneck. It is therefore necessary to accelerate this process by improving the accuracy of current methods. Rapid prototyping techniques are based on the reuse of manufactured footwear lasts so that they can be modified with CAD systems leading rapidly to new shoe models. In this work, we present a shoe last fast reconstruction method that fits current design and manufacturing processes. The method is based on the scanning of shoe last obtaining sections and establishing a fixed number of landmarks onto those sections to reconstruct the shoe last 3D surface. Automated landmark extraction is accomplished through the use of the self-organizing network, the growing neural gas (GNG), which is able to topographically map the low dimensionality of the network to the high dimensionality of the contour manifold without requiring a priori knowledge of the input space structure. Moreover, our GNG landmark method is tolerant to noise and eliminates outliers. Our method accelerates up to 12 times the surface reconstruction and filtering processes used by the current shoe last design software. The proposed method offers higher accuracy compared with methods with similar efficiency as voxel grid.

Evolution of the last koninckinids (Athyridida, Koninckinidae), a precursor signal of the early Toarcian mass extinction event in the Western Tethys

Koninckinids are a suitable group to shed light on the biotic crisis suffered by brachiopod fauna in the Early Jurassic. Koninckinid fauna recorded in the late Pliensbachian–early Toarcian from the easternmost Subbetic basin is analyzed and identified as a precursor signal for one of the most conspicuous mass extinction events of the Phylum Brachiopoda, a multi-phased interval with episodes of changing environmental conditions, whose onset can be detected from the Elisa–Mirabile subzones up to the early Toarcian extinction boundary in the lowermost Serpentinum Zone (T-OAE). The koninckinid fauna had a previously well-established migration pattern from the intra-Tethyan to the NW-European basins but a first phase with a progressive warming episode in the Pliensbachian–Toarcian transition triggered a koninckinid fauna exodus from the eastern/central Tethys toward the westernmost Mediterranean margins. A second stage shows an adaptive response to more adverse conditions in the westernmost Tethyan margins and finally, an escape and extinction phase is detected in the Atlantic areas from the mid-Polymorphum Zone onwards up to their global extinction in the lowermost Serpentinum Zone. This migration pattern is independent of the paleogeographic bioprovinciality and is unrelated to a facies-controlled pattern. The anoxic/suboxic environmental conditions should only be considered as a minor factor of partial control since well-oxygenated habitats are noted in the intra-Tethyan basins and this factor is noticeable only in the second westward migratory stage (with dwarf taxa and oligotypical assemblages). The analysis of cold-seep proxies in the Subbetic deposits suggests a radiation that is independent of methane releases in the Subbetic basin.

Propuesta de uso de last planner como sistema para la enseñanza de gestión del proceso constructivo en el grado en Arquitectura Técnica en la Universidad de Alicante

La enseñanza de Gestión del Proceso Constructivo en el grado de Arquitectura Técnica se realiza actualmente siguiendo un esquema teórico-práctico. A través de clases magistrales se define el proceso constructivo de una edificación y la relación e interdependencia entre los oficios. Estos contenidos se refuerzan en las sesiones prácticas a través de la herramienta gráfica diagrama de Gantt, donde el alumno se enfrenta de manera individual a la planificación de la obra siguiendo los criterios estipulados en la asignatura. Esta metodología no permite a los estudiantes enfrentarse a los problemas frecuentes de re-planificación y gestión de imprevistos en el entorno de la construcción. Como consecuencia, se plantea una propuesta para la implementación de la herramienta Last Planner en la asignatura como sistema de planificación colaborativa basado en la filosofía Lean Construction. A través del uso de Last Planner como técnica de Gamificación se pretende dotar de dinamismo a las sesiones teórico-prácticas. En cada sesión se simularán diferentes escenarios que requieran procesos constructivos variados, favoreciendo la motivación del alumnado, su capacidad para aprender y proponer soluciones justificadas huyendo de soluciones rígidas y estándar, y el trabajo en equipo de forma colaborativa.