Abstract
Automatic crack classification plays an essential role in road maintenance. Using many features for the classification is inefficient for implementing embedded systems with low computational ...resources makes it difficult. Therefore, this work proposes a new data dimensionality reduction (DDR) for crack classification algorithms (DDR4CC). DDR4CC reduces the required information about the cracks to only four features. Using these features, the images can be classified into longitudinal, transverse, and alligator cracks or healthy pavement. DDR4CC is compared with eight DDR methods, and the reduced set of features is analyzed using five different classification algorithms. Besides, five different datasets, generated by a combination of several public datasets, are used. We are proposing a simple DDR method with high interpretability of the data, obtaining very fast computation and high accuracy. Experiments show that DDR4CC enhances the results of the classification algorithms, providing almost perfect classifiers with a minimum computation time.
The maintenance of road pavements is an essential task to prevent major deterioration and to reduce accident rates. In this task, the detection and classification of different types of cracks on the ...roads is usually considered. However, in most cases, these tasks are not fully automated and they need to be supervised by an expert to make repair decisions. This work focuses on the automatic classification of the most common types of cracks: longitudinal cracks, transverse cracks, and alligator cracks. Our proposal combines, first, computer vision techniques for crack segmentation and second, an ensemble model (composed of different rule‐based algorithms) for the classification. This approach achieves an average precision and recall values greater than 94% for three analyzed data sets improving the results in comparison to other approaches.
High energy muons in extensive air showers Gámez, C.; Gutiérrez, M.; Martínez, J.S. ...
Journal of cosmology and astroparticle physics,
01/2020, Letnik:
2020, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The production of very high energy muons inside an extensive air shower is observable at ν telescopes and sensitive to the composition of the primary cosmic ray. Here we discuss five different ...sources of these muons: pion and kaon decays; charmed hadron decays; rare decays of unflavored mesons; photon conversion into a muon pair; and photon conversion into a J/ψ vector meson decaying into muons. We solve the cascade equations for a 1010.5 GeV proton primary and find that unflavored mesons and gamma conversions are the two main sources of E≥108.5 GeV muons, while charm decays dominate at 105.5GeV<E<108.5GeV. In inclined events one of these muons may deposite a large fraction of its energy near the surface, implying fluctuations in the longitudinal profile of the shower and in the muon to electron count at the ground level. In particular, we show that 1 out of 6 proton showers of 1010.5 GeV include an E>106 GeV deposition within 500 g/cm2, while only in 1 out of 330 showers it is above 107 GeV . We also show that the production of high energy muons is very different in proton, iron or photon showers (e.g., conversions γ μ+μ− are the main source of E≥104 GeV muons in photon showers). Finally, we use Monte Carlo simulations to discuss the validity of our results.
In the last decade, Mexico has been prominent among the Upper-middle-income countries (UMC) due to the application of its Funding Program for Housing Solutions (FPHS) in dealing with social housing.
...This paper shows the results of the evaluations carried out, through the internationally recognized Building Sustainability Rating Systems (BSRS), on different housing units built under this program. It was necessary to carry out a normalization criteria process (NCP) due to the particular characteristics of each BSRS and the complexity they presented in carrying out a comparative analysis.
Case studies indicate that housing developed by the FPHS obtained low qualifications according to internationally focused BSRS, with significant deficiencies concerning materials, energy efficiency, indoor environmental quality, and management. However, this study provides indicators of its possible integration in the social housing of countries with characteristics analogous to those of Mexico. Among all indicators, that those referring to the urban environment are capable of being integrated into the social housing.
Among the findings, some aspects of the FPHS evaluation process impede the integration of sustainable characteristics in Mexican social housing. On the other hand, the FPHS evaluation model, which gives priority to urban environment aspects above all else, may represent a new paradigm towards the achievement of the sustainable social housing (SSH).
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•The new paradigm of urban environment will allow sustainable social housing.•Mexican sustainable social housing has aspects with application in another countries.•Mexican sustainable social housing does not comply with other global certifications.•The most significant deficiencies identified were: Materials and energy efficiency.
Recycled concrete aggregate (RA) from pavement demolition was used to make concrete. Ten concrete mixtures with different replacement percentages of RA (coarse and fine) were made. The corrosion rate ...of steel and the electrical resistivity of concrete were determined on reinforced concrete specimens subjected to wetting-drying cycles (3.5% solution of NaCl). Corrosion rate was determined using the electrochemical technique of linear polarization resistance, while the electrical resistivity was measured by electrochemical impedance spectroscopy. The results show that the use of RA introduces more interfaces in concrete, which accelerates the steel corrosion process because the porosity increases and the electrical resistivity decreases. However, steel corrosion and the electrical resistivity in concrete are not significantly influenced by replacing a maximum 30% of coarse aggregate or 20% of fine aggregate with RA.
Acute hepatopancreatic necrosis disease (AHPND) outbreaks caused by Vibrio parahaemolyticus (VPAHPND) emerged in Mexico in 2013, causing a 65% drop in shrimp tonnage produced. This work aimed to ...isolate bacterial strains from Mexican marine ecosystems antagonistic towards VPAHPND. Among 258 bacterial isolates, only 17 showed antagonist activity in vitro, but only (Bacillus pumilus‐Y100, B. pumilus‐Y119, B. pumilus‐43, Vibrio alginolyticus‐32a and V. campbellii‐H‐A) were chosen for bioassay challenge. These probiotic bacteria were sprayed on commercial shrimp pellets, and experimental infection was carried out by immersing the shrimp in VPAHPND inoculum. Bacterial strains 32a, Y100 and H‐A significantly reduced the cumulative mortality of shrimp exposed to AHPND (4.76%, 12.54% and 16% respectively). Y119 and 43 did not show any beneficial effect against VPAHPND but were pathogenic in previous assays with post‐larval white shrimp and bioassay trials. Concerning the qPCR results, the presence of low numbers of DNA copies of VPAHPND was found only in the H‐A trial, suggesting that H‐A exerts a bacteriostatic effect; in contrast, the results for 32a, Y100, Y119 and 43 were negative, indicating that these strains exhibited a microbicidal effect against VPAHPND. The histopathological results agreed with the qPCR results and did not show compatible lesions caused by AHPND. In conclusion, 32a and Y100 seem to be the first antagonists to specifically inhibit VPAHPND in vivo.
Under ballast mats (UBM) have demonstrated their capacity to reduce section stiffness and ballast degradation. However, UBM can cause ballast destabilisation under some circumstances due to excessive ...vertical track deflections, requiring the installation of geogrids over the mat which increases costs and time. As alternative to this solution, this paper shows the design of GridMat: a sustainable technology for ballasted railways that combines the concepts of geogrids and under ballast mats (UBM) manufactured from recycled crumb rubber. This aims to provide damping capacity while limiting the oscillations and settlement of ballast layer. To obtain the optimal GridMat design, five different configurations varying the aperture size and void areas were assessed through laboratory box tests reproducing the track section including the GridMat. Results showed that the optimal Gridmat was of 55 mm aperture seize and 25% void area. To evaluate the sustainability of this design, the expected number of conservation and renewal operations were calculated from full-scale laboratory tests and a life-cycle assessment and life-cycle cost analysis were undertaken. GridMat showed long-term reduction in ballast degradation and track settlement, reducing need for maintenance and renewal operations in comparison with standard mats.
Recently, reports on the fabrication of nonstructural configuration have generated scientific interest due to increased awareness of the oxide nanotubes in the biomedical implant field and other ...industrial approaches. Here, highly ordered ZrO2TiO2Nb2O5Al2O3 nanotube arrays were grown by physical vapor deposition (PVD) of a zirconium layer on titanium-niobium alloy implant (IMPTi67) and succeeding anodic oxidation at a constant voltage (60 V) with exposure times ranging from 30 to 300 min. To crystallize the resulting mixed oxide nanotubes, heat treatment was also applied. The nanotubes were placed in an atmospheric furnace at temperatures ranging from 450 to 800 °C for 2 h. This treatment provided a morphological evolution was strongly influenced by the anodization time, where highly aligned bamboo-shaped oxide nanotubes (161 ± 44 nm in inside diameter and ~1 ...m in length) were formed after 300 min of anodization. After annealing at temperature below 500 °C, the nano-array configuration remained stable and the average inner diameter decreased to around 40 nm. The effects of anodically fabrication time on the adhesion strength of four-phase multilayered mixed oxide nanotubes on anodized Zr/IMPTi67 surfaces assed by microscratch analysis. From the results, increasing the annealing temperature further to 800 °C fully destroyed the nanotubes and consequently the tubular arrangement was converted to a coarse grain structure. It was revealed that annealing at 450 °C for 2 h was the optimum conditions for stable nanotubular array generation, where the highest adhesion strength (shifted from 2595.59 to 2640.12 mN), microhardness (372 HV) and hydrophilicity (15 ± 1°) were recorded. It is notify that the adhesion strength of highly ordered mixed nanotubes was remarkably decreased after thermal treatment at 800 °C (1817.51 mN). Through the laser spallation analysis, the intrinsic adhesion strength of the Zr/IMPTi67 interface was found to be at 63 MPa, while the first stages of failure occurred at a stress state of 35 MPa. The adhesion of the film with the tubular structure proved to have a significantly larger adhesion strength of 246 MPa for the complete failure and 203 MPa for incipient stages of spallation. The considered surface modification can be an effective step in determining the interface strength between biomedical implants and the nanostructured coatings.
An adequate moisture resistance is a key element to guarantee the durability of asphalt materials. This paper identifies the influence of filler typology and bitumen content on the mechanical ...response of asphalt mortars before and after water action. Two fillers were evaluated: Portland cement and Calcium carbonate, along with different contents of a penetration bitumen (B35/50). Stiffness, ductility, and fatigue were evaluated through a new protocol for asphalt mortar samples using a 3-point-bending test on DMA (Dynamic Mechanical Analyzer). The use of Portland cement presents higher stiffness, lower ductility, and improved fatigue and water resistance compared to Calcium carbonate. It is also possible to optimize bitumen content based on fatigue results. Content beyond the optimal reduce variations after water action but compromise fatigue resistance. Lower content leads to a poorer performance in both terms. This methodology enables asphalt mortar characterisation as a tool to optimise the design of asphalt materials.
Abstract Reports on taxonomic identification of E6/HPV 16 variants, don't have a worldwide, updated and unified criterion for clustering and nomenclature. Our aim was to update the existing criterion ...and propose a new one for clustering and nomenclature for E6/HPV 16 molecular variants based on the descriptive and comparative analyses of nucleotide sequences. A systematic search of the publications between 1991 and 2010 was carried out in PUBMED and manually. 240 E6/HPV 16 variants were identified. 157 were classified as European (E), 24 as Asian (As), 14 as Asian American (AA), 11 as North American 1 (NA 1), 19 as African 1 (Af 1) and 15 as African 2 (Af 2). Three classes were determined for the E, 3 each for the As, Af 2 and AA branches, 4 classes for the NA 1 and 6 for the Af 1 branch. This study reports our results and proposes an updated criterion for clustering and nomenclature that will be useful for E6 variant identification.
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