330 research outputs found
Qualitative fault tree for the analysis of slope stability loss in road infrastructure
TRA Lisbon 2022 Conference Proceedings Transport Research Arena (TRA Lisbon 2022),14th-17th November 2022, Lisboa, PortugalLandslides are natural hazards all over the world, being the loss of slope stability in transport infrastructures considered small-scale landslides causing economic and human losses. Although there are many examples in the literature for the general analysis of landslides susceptibility, little information is available to analyze slopes at a local scale. The objective of this work is to identify all the slopes in road infrastructure, select those located in landslide susceptibility areas and apply a qualitative fault tree, also defined in this work, to determine the factors which can cause the slope stability loss. The results obtained are useful for each critical slope.Agencia Estatal de Investigación | Ref. PID2019-108816RB-I00Agencia Estatal de Investigación | Ref. PRE2020-09622
External multi-modal imaging sensor calibration for sensor fusion: A review
Multi-modal data fusion has gained popularity due to its diverse applications, leading to an increased demand for external sensor calibration. Despite several proven calibration solutions, they fail to fully satisfy all the evaluation criteria, including accuracy, automation, and robustness. Thus, this review aims to contribute to this growing field by examining recent research on multi-modal imaging sensor calibration and proposing future research directions. The literature review comprehensively explains the various characteristics and conditions of different multi-modal external calibration methods, including traditional motion-based calibration and feature-based calibration. Target-based calibration and targetless calibration are two types of feature-based calibration, which are discussed in detail. Furthermore, the paper highlights systematic calibration as an emerging research direction. Finally, this review concludes crucial factors for evaluating calibration methods and provides a comprehensive discussion on their applications, with the aim of providing valuable insights to guide future research directions. Future research should focus primarily on the capability of online targetless calibration and systematic multi-modal sensor calibration.Ministerio de Ciencia, Innovación y Universidades | Ref. PID2019-108816RB-I0
Automatic detection to inventory road slopes using open LiDAR point clouds
The transport infrastructure of a country facilitates the development and growth of its economy and improves the
quality of life of its inhabitants. Increasing its resilience to different types of risks to improve performance is
becoming more important. In the current context of climate change, natural hazards are more severe and
frequent. In this article, we focus on rockfall as a natural hazard for roads that occurs in small areas in the vicinity
of natural or cut slopes, causing road safety problems by invading part of the road.
This article aims to inventory the slopes along the road, identifying the area of the road which would be
invaded in case of a rockfall. A methodology divided into two blocks is proposed. First, for slope detection and
inventory, an algorithm is developed based on open LiDAR point clouds analysis. The second block consists of
estimating the invaded road area if a rockfall occurs on each of the inventoried slopes, using a combination of
RockGIS software and the Monte Carlo method. The methodology was applied in five case studies: three sections
on motorways and two sections on national roads. The results obtained for slope detection show higher rates in
the case studies analyzing motorways, with a precision of 100%, a recovery rate of greater than 93.4%, and an F1
score of greater than 0.96. The results in the invaded area of the road show that 11 slopes would cause a total cut
of the motorway in one of the directions if a rockfall occurs.
These results are useful for infrastructure managers to remotely obtain an inventory of road slopes and know
which of them would affect road safety. Also, the results can serve as input for the Intelligent Transportation
System and allow the exchange of information under the Building Information Model approach.Ministerio de Ciencia, Innovación y Universidades | Ref. PID2019-108816RB-I00Ministerio de Ciencia, Innovación y Universidades | Ref. PRE2020-096222European Commission | Ref. H2020, n. 95533
Comparing Mobile and Aerial Laser Scanner point cloud data sets for automating the detection and delimitation procedure of safety-critical near-road slopes
An inappropriately maintained road cut-slope is likely to fail, resulting in landslides or falling rocks that compromise road safety. Thus, road managers need to know the location of dangerous slopes along the road in order to prevent these events from happening. In this article, we compare two different approaches for conducting the digitization of the road environment and the automatic detection and delimitation of road slopes: Mobile Laser Scanners (MLS) and Aerial Laser Scanners (ALS). The point clouds obtained using the first kind of devices are dense, rich in detail and generated from a ground perspective; the second type of scanners produce less dense clouds from a zenithal perspective. We explore what is the effect of the point cloud density and scanner point of view over the slope detection procedure. Two road segments from the Spanish A55 and A52 highways were used as study zones, and a total of 28.61 km were analyzed. Better detection and delimitation results were achieved when using the ALS data and its corresponding algorithm. It was observed that the higher point density and detail of the MLS clouds were not an advantage for the slope detection task, and that measuring the road from a terrestrial perspective affected in a negative way during the detection process: the crest of the slopes often remained unmeasured, hidden behind vegetation or man-made elements, thus resulting in the slopes not being complete in the MLS clouds. Meanwhile, the whole slope structure is scanned when the scene is measured from an aerial perspective, henceforth obtaining better detection rates despite the relatively low resolution. The findings of this study provide valuable information in the field of road asset management, and help road managers make decisions when choosing what technology to use for the data gathering process.Agencia Estatal de Investigación | Ref. PID2022-140662OB-I00Universidade de Vigo/CISU
Heuristic generation of multispectral labeled point cloud datasets for deep learning models
Abstract. Deep Learning (DL) models need big enough datasets for training, especially those that deal with point clouds. Artificial generation of these datasets can complement the real ones by improving the learning rate of DL architectures. Also, Light Detection and Ranging (LiDAR) scanners can be studied by comparing its performing with artificial point clouds. A methodology for simulate LiDAR-based artificial point clouds is presented in this work in order to get train datasets already labelled for DL models. In addition to the geometry design, a spectral simulation will be also performed so that all points in each cloud will have its 3 dimensional coordinates (x, y, z), a label designing which category it belongs to (vegetation, traffic sign, road pavement, …) and an intensity estimator based on physical properties as reflectance.Ministerio de Ciencia, Innovación y Universidades | Ref. PCI2020-120705-
The Influence of Sociological Variables on Users’ Feelings about Programmatic Advertising and the Use of Ad-Blockers
The evolution of digital advertising, which is aimed at a mass audience, to programmatic advertising, which is aimed at individual users depending on their profile, has raised concerns about the use of personal data and invasion of user privacy on the Internet. Concerned users install ad-blockers that prevent users from seeing ads and this has resulted in many companies using antiad-blockers. This study investigates the sociological variables that make users feel that advertising
is annoying and then decide to use ad-blockers to avoid it. Our results provide useful information for companies to appropriately segment user profiles. To do this, data collected from Internet users (n = 19,973) about what makes online advertising annoying and why they decide to use ad-blockers are analyzed. First, the existing literature on the subject was reviewed and then the relevant sociological variables that influence users’ feelings about online advertising and the use of ad-blockers were investigated. This work contributes new information to the discussion about user privacy on the
Internet. Some of the key findings suggest that Internet advertising can be very intrusive for many users and that all the variables investigated, except marital status and education, influence the users’opinions. It was also found that all the variables in this study are important when a user decides to use an ad-blocker. A clear and inverse correlation between age and opinion about advertising as annoying could be seen, along with a clear difference of opinion due to gender. The results
suggest that users without children use ad-blockers the least, while retirees and housewives use them the most
A top-down approach for a multi-scale identification of risk areas in infrastructures: particularization in a case study on road safety
Introduction: Transport infrastructures have an important function in society and the development of a country. In Spain, the most used modes of traveler transport are road and rail, far ahead of other means of transport such as air or maritime transport. Both rail and road infrastructures can be affected by numerous hazards, endangering their performance and the safety of users. This study proposes a methodology with a multiscale top-down approach to identify the areas affected by fire, landslide, and safety in road and rail infrastructures in Galicia (Northwest Spain).Methodology: The methodology is developed in three steps, coinciding with the three scales considered in this work: network-, system-, and object-level. In the first step, risk areas are identified and prioritized, resulting in the most critical safety risk in a motorway section. This area defines a study scenario composed of a location (A-55 motorway) and the associated risk (road safety). In the second step, the road safety factors within this scenario are selected, hierarchized, and weighted using a combination of Multi-Criteria Decision-Making methods including the Analytical Hierarchy Process and the Best–Worst Method. Finally, a risk map is generated based on the weighting of infrastructure-related safety factors and compared to real historical accident data for validation. The methodology is based on road and risk assessment standards and only information in the public domain is used.Results: Results show that only 3 segments out of 153 were classified incorrectly, which supports a probability higher than 95% of agreement with real data (at 5% significance level). In a conclusion, the overall methodology exhibits a high potential for hazard prevention and road-safety enhancement.Agencia Estatal de Investigación | Ref. PID2019-108816RB-I00Agencia Estatal de Investigación | Ref. PRE2020-09622
Omega 3 fatty acids induce a marked reduction of apolipoprotein B48 when added to fluvastatin in patients with type 2 diabetes and mixed hyperlipidemia: a preliminary report
<p>Abstract</p> <p>Backgorund</p> <p>Mixed hyperlipidemia is common in patients with diabetes. Statins, the choice drugs, are effective at reducing lipoproteins that contain apolipoprotein B100, but they fail to exert good control over intestinal lipoproteins, which have an atherogenic potential. We describe the effect of prescription omega 3 fatty acids on the intestinal lipoproteins in patients with type 2 diabetes who were already receiving fluvastatin 80 mg per day.</p> <p>Methods</p> <p>Patients with type 2 diabetes and mixed hyperlipidemia were recruited. Fasting lipid profile was taken when patients were treated with diet, diet plus 80 mg of fluvastatin and diet plus fluvastatin 80 mg and 4 g of prescription omega 3 fatty acids. The intestinal lipoproteins were quantified by the fasting concentration of apolipoprotein B48 using a commercial ELISA.</p> <p>Results</p> <p>The addition of 4 g of prescription omega 3 was followed by significant reductions in the levels of triglycerides, VLDL triglycerides and the triglyceride/HDL cholesterol ratio, and an increase in HDL cholesterol (P < 0.05). Fluvastatin induced a reduction of 26% in B100 (P < 0.05) and 14% in B48 (NS). However, the addition of omega 3 fatty acids enhanced this reduction to 32% in B100 (NS) and up to 36% in B48 (P < 0.05).</p> <p>Conclusion</p> <p>Our preliminary findings therefore suggest an additional benefit on postprandial atherogenic particles when omega 3 fatty acids are added to standard treatment with fluvastatin.</p
La formación de docentes en pregrado, para el trabajo con multigrado en zonas rurales. (Original)
In the research, the authors work the problem of inadequacies in the teacher's professional training to work with multiple class. Meanwhile, the objectives are framed, firstly, to critically analyze the theoretical references that have been reviewed on the subject discussed and secondly, to propose a didactic alternative to structure the teaching-learning process in multigrade classrooms so that it is favored, and facilitate and improve the scientific-pedagogical work of teachers. In this regard, to structure said process in this context, a thematic plan is offered for those in initial training. Here the main issues to be addressed in the overcoming are incorporated, depending on the interests that exist in the aforementioned space. In this particular, the most relevant value that is fostered is equity, when assessing with a professional attitude, how education should be directed towards equal opportunity in the conditions of the pedagogical process of the sector where the school is conceived as a space for the integration of all social areas. To carry out the research in question, two groups of methods were used: the theoretical. Of which the analytic-synthetic, inductive-deductive, hermeneutical and modelation were used, fundamentally; and that of the empirical. Of the latter, the following were used: observation, documentary study, interviews and questionnaire. In addition, the criteria of specialists and users were used to assess this proposal. Meanwhile, the experimentation allowed to verify in pedagogical practice the value of the proposed didactic actions.En la investigación, los autores atienden el problema de las insuficiencias en la formación profesional del maestro para trabajar con grados múltiples. Por tanto, los objetivos se enmarcan, primero, en analizar crÃticamente los referentes teóricos que sobre el asunto tratado se han revisado y en segundo lugar, proponer una alternativa didáctica para estructurar el proceso de enseñanza-aprendizaje en aulas multigrados de manera que este favorezca, facilite y perfeccione la labor cientÃfico-pedagógica de los docentes. Al respecto, para estructurar dicho proceso en este contexto, se ofrece un plan temático para los que están en formación inicial. Aquà se incorporan los principales temas a abordar en la superación, en dependencia de los intereses que en el espacio referido existan. En este particular, el valor más relevante que se propicia es la equidad, al valorar con una actitud profesional, cómo la educación debe dirigirse hacia la igualdad de oportunidad en las condiciones del proceso pedagógico del sector donde se concibe la escuela como espacio de integración de todos los ámbitos sociales. Para la concreción del estudio en cuestión, se emplearon dos grupos de métodos: los teóricos y los empÃricos. De los cuales se utilizaron, en el primer caso fundamentalmente, el analÃtico-sintético, inductivo-deductivo, hermenéutico y la modelación. De los últimos se emplearon: la observación, estudio documental, entrevistas y cuestionario. Además se recurrió a criterios de especialistas y usuarios para valorar dicha propuesta. En tanto, la experimentación permitió comprobar en la práctica pedagógica el valor de las acciones didácticas propuestas
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