Phreatic Surface Estimation In MSE Wall With Geocomposite Back Drainage

This study proposes a simple mathematic model for approximating the level of phreatic surface inside the protected zone in mechanical stabilized earth wall with back drain installation though the position of phreatic surface at the drainage interface (ho) which reflects the maximum level of phreatic surface in the protected zone. The proposed model was established based on dataset taken from 180 simulation cases caried out in Plaxis environment. Regression results present a combination of significant effects and major role to maximum water level in the protected zone (ho) of a ratio of length from upstream water to the drainage face to the wall height (L/H), a soil permeabilities coefficient (k) and a transmissivity of the drainage material (Tnet). The proposed model can facilitate design of drainage material to achieve desired level of phreatic surface in the protected zone.

Optical Dual Laser Based Sensor Denoising for OnlineMetal Sheet Flatness Measurement Using Hermite Interpolation

Flatness sensors are required for quality control of metal sheets obtained from steel coils by roller leveling and cutting systems. This article presents an innovative system for real-time robust surface estimation of flattened metal sheets composed of two line lasers and a conventional 2D camera. Laser plane triangulation is used for surface height retrieval along virtual surface fibers. The dual laser allows instantaneous robust and quick estimation of the fiber height derivatives. Hermite cubic interpolation along the fibers allows real-time surface estimation and high frequency noise removal. Noise sources are the vibrations induced in the sheet by its movements during the process and some mechanical events, such as cutting into separate pieces. The system is validated on synthetic surfaces that simulate the most critical noise sources and on real data obtained from the installation of the sensor in an actual steel mill. In the comparison with conventional filtering methods, we achieve at least a 41% of improvement in the accuracy of the surface reconstruction.

CUBA SURFACE ESTIMATION FROM SHORELINE MAPPING, GENERATED BY SENTINEL-2 IMAGE PROCESSING

The coastal with its geographical elements are modified over time, changes that may occur in the long or short term so, shoreline represented in the cartographic documents does not always match with reality. Also, the coastline does not have a well-defined length as results from the fractal-like properties of coastlines, i.e., the fact that a coastline typically has a fractal dimension so, its representation depends to many factors like the cartographic method used, the resolution of the image and the scale of the map. On the other hand, the shoreline is general use to estimate the surface of the landmass, so is important to get a cartographic product with accuracy in a time. Taking into account these elements, this paper is focus in a surface estimation of total Cuban island and keys. To achieved, an expeditious method was used, from the application of geometric corrections to multispectral SENTINEL-2 images, followed by a band algebra using the NDWI index. After those process the automated extraction of shoreline was conducted and finally, refining the vectors by cartographic editing without compromising the accuracy of the results. As a result, two coast lines were obtained from the territory, one in the rainy season and the other in the dry season. The spatial analyses were oriented to surface determination and they were carried out over shoreline in dry season and rainy season, the results were contrasted with the official data published in 2016.