Learning based on 3D photogrammetry models to evaluate the competences in visual testing of welds

The present work describes a new learning methodology based on the latest scientific research aimed at the three-dimensional macro-photogrammetric reconstruction of welds, which allows the generation of teaching materials aimed at the acquisition and evaluation of competencies in the non-destructive testing laboratory activities without the need for a physical displacement to the physical installation. This methodology, which can be cataloged within those based on virtual laboratories, is applicable in e-learning courses or can also be used as support material for face-to-face programs, mainly in the bachelor’s and master’s related to mechanical, naval and aeronautical engineering. The distribution of the packages is easy to load in learning management system in order to work with the models with open software, easily and without the need for additional cost

Suitability of Automatic Photogrammetric Reconstruction Configurations for Small Archaeological Remains

19 p.Three-dimensional (3D) reconstruction is a useful technique for the documentation, characterization, and evaluation of small archeological objects. In this research, a comparison among different photogrammetric setups that use different lenses (macro and standard zoom) and dense point cloud generation calibration processes for real specific objects of archaeological interest with different textures, geometries, and materials is raised using an automated data collection. The data acquisition protocol is carried out from a platform with control points referenced with a metrology absolute arm to accurately define a common spatial reference system. The photogrammetric reconstruction is performed considering a camera pre-calibration as well as a self-calibration. The latter is common for most data acquisition situations in archaeology. The results for the different lenses and calibration processes are compared based on a robust statistical analysis, which entails the estimation of both standard Gaussian and non-parametric estimators, to assess the accuracy potential of different configurations. As a result, 95% of the reconstructed points show geometric discrepancies lower than 0.85 mm for the most unfavorable case and less than 0.35 mm for the other casesS

Weld bead detection based on 3D geometric features and machine learning approaches

14 p.Weld bead detection is essential for automated welding inspection processes. The non-invasive passive techniques, such as photogrammetry, are quickly evolving to provide a 3D point cloud with submillimeter precision and spatial resolution. However, its application in weld visual inspection has not been extensively studied. The derived 3D point clouds, despite the lack of topological information, store significant information for the weld-plaque segmentation. Although the weld bead detection is being carried out over images or based on laser profiles, its characterization by means of 3D geometrical features has not been assessed. Moreover, it is possible to combine machine learning approaches and the 3D features in order to realize the full potential of the weld bead segmentation of 3D submillimeter point clouds. In this paper, the novelty is focused on the study of 3D features on real cases to identify the most relevant ones for weld bead detection on the basis of the information gain. For this novel contribution, the influence of neighborhood size for covariance matrix computation, decision tree algorithms, and split criteria are analyzed to assess the optimal results. The classification accuracy is evaluated by the degree of agreement of the classified data by the kappa index and the area under the receiver operating characteristic (ROC) curve. The experimental results show that the proposed novel methodology performs better than 0.85 for the kappa index and better than 0.95 for ROC area.S

Interpretation of cavitation using CFD simulation as a low-cost learning activity compatible with e-learning

7 p.In this conference paper, an activity based on computational fluid dynamics that allows STEM students to know the phenomenon of cavitation is proposed. Cavitation is a dangerous phenomenon that occurs in pressurized fluid when they rapidly change of pressure in a liquid and a small vapor-filled cavity is generated in regions where the pressure is low. These cavities (or bubbles) are highly damaging to machines and fluid systems. Due to its dangerousness, it is necessary for the engineer to know the consequences of the cavitation and the factors involved in the phenomenon, in order to design solutions that avoid or minimize the damage caused. The design process of the activity starts with a critical analysis to cover the requirements that allow the activity to be carried out in the simplest way possible, using a model and a simplified computational pipeline that allows maximum adaptation to the real phenomenon without the need for laboratory equipment so that it can be integrated into subjects in the field of fluid-mechanics and maintenance engineeringS

Detection of Geothermal Potential Zones Using Remote Sensing Techniques

21 p.The transition towards a new sustainable energy model—replacing fossil fuels with renewable sources—presents a multidisciplinary challenge. One of the major decarbonization issues is the question of to optimize energy transport networks for renewable energy sources. Within the range of renewable energies, the location and evaluation of geothermal energy is associated with costly processes, such as drilling, which limit its use. Therefore, the present research is aimed at applying different geomatic techniques for the detection of geothermal resources. The workflow is based on free/open access geospatial data. More specifically, remote sensing information (Sentinel-2A and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER)), geological information, distribution of gravimetric anomalies, and geographic information systems have been used to detect areas of shallow geothermal potential in the northwest of the province of Orense, Spain. Due to the variety of parameters involved, and the complexity of the classification, a random forest classifier was employed, since this algorithm works well with large sets of data and can be used with categorical and numerical data. The results obtained allowed identifying a susceptible area to be operated on with a geothermal potential of 80 W·m−1 or higherS

Simulation of a Real Call for Research Projects as Activity to Acquire Research Skills: Perception Analysis of Teacher Candidates

17 p.In this research, a novel methodology based on the simulation of a call for research projects was applied for the training of STEM secondary school teachers, with results raised and analyzed to determine the response of the students to this new methodology. The activity was applied in the same course during two academic years with student groups from very different teaching specialties such as mathematics, physics and chemistry, biology and geology, technology and health processes who were studying the Master’s Degree in Secondary Education, specifically, the 3 European Credit Transfer and Accumulation System (ECTS) course of Initiation to Educational Research (IER), this Master’s course being mandatory for working as a secondary professor. The Master’s students are asked to write their own research project proposals for a fictitious call on a topic freely chosen by them, which might have been related to the research line of the final Master’s thesis. In it, they had to propose all the contents studied in the course (such as writing a brief state of the art, establishing a research team, setting objectives, a description of the methodology for educational research, instruments, a plan for the dissemination of the results, the needed resources, etc.). The students’ perceptions of the usefulness and reality of what they had learned for their professional development and for writing their final theses were assessed. The results based on the perceptions of the students demonstrate that the activity had been useful for assimilating concepts related to educational research in the context of secondary education (research skills), which will be useful for improving the critical sense of the students (teacher candidates) and for their professional future in the context of applied research in day-to-day secondary teacher activities. Furthermore, the results show the activity was useful for the development of the final Master’s thesis. The difficult aspects that the activity presented for them were analyzed. The results were statistically compared for the students of the different specialties, deducing, in all cases, a homogeneous good acceptance with slight differences between themS

Learning physical geodesy. Application case to geoid undulation computation

7 p.The present article shows a novel approach for the acquisition of competences related to physical geodesy in the Bachelor’s Degree in Geomatics using virtual materials to promote the autonomous learning and support it during exceptional periods of confinement, like the Covid-19 pandemic. More specifically, the article is focused in the geoid undulation determination, which is a critical issue in hydraulic works, land subsidence, and civil projects. So, this concept has to be learned in the Bachelor’s Degree in Geomatics for the proper acquisition of competences. The approach is aimed to three-dimensional fitting techniques and statistical analysis to improve the comprehension and interpretation of the different local geoid models from the same set of field measurements, and therefore the conclusions and analysis derived from them for the subsequent Geomatic practical works. The current contribution is originated from the virtual laboratories’ paradigm, as it is proposed the use of virtual materials for the acquisition and evaluation of competences and skills in an asynchronous way, that can be use not only for and e-learning or b-learning programs, but also as support for traditional face to face programs. The present contribution will help the students to contextualize the theoretical knowledge, so better understand the challenges they will face in the working market as future professionalsS

Learning and comprehension of terrain representation in cartographic design

7 p.One of the usual tasks of engineers in Geomatics and Surveying is the representation of the terrain for different purposes. Within the teaching of Geomatic Engineering bachelor, the skills related to the critical assessment, contextualization, and interoperability of said terrain models require further development so that future professionals can improve their understanding of the problem, and can address day-to-day problems of fusion of data from different sources and qualities. This contribution focuses on the cartographic problem of integrating different terrain representations from various official sources and with different specifications. To this end, a teaching-learning activity based on the use of data and free software is proposed to enhance the preparation and skills of future geomatics engineering professionals, providing them with added value. The present methodology complies with the requirements of reality, economy and quality established in the scientific literatureS

Software libre para la resolución de ejercicios de álgebra

El presente material didáctico está centrado en el empleo del software libre de cálculo científico SciLab [1], orientado a la docencia de las asignaturas de álgebra y matemáticas y como material complementario para aquellas asignaturas de ingeniería que requieran herramientas informáticas para la resolución de problemas algebraicos y numérico