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Augmented Lagrangian method for a total variation-based model for demodulating phase discontinuities

RICARDO LEGARDA SAENZ CARLOS FRANCISCO BRITO LOEZA (2020)

In this work, we reformulate the method presented in App. Opt. 53:2297 (2014) as a constrained minimization problem using the augmented Lagrangian method. First we introduce the new method and then describe the numerical solution, which results in a simple algorithm. Numerical experiments with both synthetic and real fringe patterns show the accuracy and simplicity of the resulting algorithm.

Article

CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA INGENIERÍA Y TECNOLOGÍA Phase demodulation Fringe analysis Inverse problems Variational models

A mean curvature regularized based model for demodulating phase maps from fringe patterns

CARLOS FRANCISCO BRITO LOEZA RICARDO LEGARDA SAENZ ARTURO ESPINOSA ROMERO ANABEL MARTIN GONZALEZ (2018)

We introduce a variational method for demodulating phase maps from fringe patterns. This new method is based on the mean curvature of the level sets of the phase surface that is used for regularization. The performance of the method is illustrated with both synthetic and real data.

Article

CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA INGENIERÍA Y TECNOLOGÍA Fringe analysis Interferometry High-order regularization Variational models

Spatio-temporal land-use changes in the Colima-Villa de Álvarez metropolitan area, and their relationship to floodings

Spatio-temporal land-use changes in the Colima-Villa de Álvarez metropolitan area, and their relationship to floodings

MYRNA LORENA PEREZ GONZALEZ LUCIA CAPRA PEDOL NORMA ANGELICA DAVILA HERNANDEZ LORENZO BORSELLI SARA SOLIS VALDEZ AZALEA JUDITH ORTIZ RODRIGUEZ (2017)

Demographic growth and consequent land-use changes are consid - ered one of the main factors causing inundations in many cities in de - veloping countries. During the last decade, the city of Colima, Mexico, has suffered from an increase in flooding events. These episodes mostly occurred during tropical rainstorms associated to hurricanes (such as Jova in 2011, Manuel in 2013, and Patricia in 2015, all with average accumulated rainfall of 200 mm in 24 h), as well as during short- duration, high-intensity rainfall events at the beginning of the rainy season. To define the mechanisms leading to the increased occurrence of floodings, a space-time analysis of land-use changes, coupled with the characterization of natural and urban soils, are presented here for the Colima metropolitan area. Three land-use categories were created: native land (N1), urban land (N4), and cultivated land (N5). Each of these categories has subcategories depending on vegetative cover and/ or level of urbanization. SPOT imagery acquired in 2005, 2009, and 2015 was classified to analyze the spatial and temporal changes in land use. Thirty-two soil samples representative of different land uses were analyzed to obtain their physical and chemical properties such as granulometry, bulk and particle densities, porosity, and organic matter content. Hydraulic conductivity tests were performed in situ using a drip-infiltrometer device. The temporal and spatial analysis of SPOT images revealed that most changes in land use correspond to urban area and cultivated land, the former showing an increase and the latter a drastic decrease, especially towards the northern part of the city, where urban growth is evident for the 20052009 period. Analyzed soils from cultivated land have the highest permeability, and engineered soils correspond to the least permeable soils in the area; consequently, replacement of agriculture with housing has significant impacts on the rainfall-runoff process. These results indicate that as more permeable land area is substituted by disturbed urban soils, the infiltration capability will be reduced, leading to increasing flooding frequency in the Colima-Villa de Álvarez metropolitan area. To prevent and reduce the disruptive im - pact of inundation in the Colima metropolitan area, it is recommended to have adequate management of land-use change and to conserve the permeable areas around the city. In addition, it is necessary to revise the hydraulic infrastructure of the existing urban areas and to properly define the most suitable locations for future ones. Avoiding develop - ment in flood-prone areas through planning and zoning ordinances may reduce loss of life and damage to property.

Article

Ciencias de la Tierra Flooding land use hydraulic conductivity SPOT images Colima Mexico Ciencias de la Tierra Flooding land use hydraulic conductivity SPOT images Colima Mexico CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA