The Experts below are selected from a list of 115629 Experts worldwide ranked by ideXlab platform

Antonio Galgaro - One of the best experts on this subject based on the ideXlab platform.

  • grid_strain and grid_strain3 software packages for strain Field Computation in 2d and 3d environments
    2008
    Co-Authors: Giordano Teza, A Pesci, Antonio Galgaro
    Abstract:

    Two Matlab(TM) software packages for strain Field Computation, starting from displacements of experimental points (EPs), are here presented. In particular, grid_strain estimates the strain on the nodes of a regular planar grid, whereas grid_strain3 operates on the points of a digital terrain model (DTM). In both cases, the Computations are performed in a modified least-square approach, emphasizing the effects of nearest points. This approach allows users to operate at different scales of analysis by introducing a scale factor to reduce or also exclude points too far from grid nodes. The input data are displacements (or velocities) that can be provided by several techniques (e.g. GPS, total topographical station, terrestrial laser scanner). The analysis can be applied to both regional- and local-scale phenomena, to study tectonic crustal deformations (strain ~10^-^8-10^-^6) or rapid landslide collapses (10^-^4-10^2), and to characterize the kinematics of the studied system. Errors on strains and geometric significance of the results are also provided.

  • characterization of landslide ground surface kinematics from terrestrial laser scanning and strain Field Computation
    2008
    Co-Authors: Giordano Teza, A Pesci, Rinaldo Genevois, Antonio Galgaro
    Abstract:

    Assessment and mitigation of the risk induced by landslide activation need an appropriate phenomenon investigation, to obtain useful information about the failure processes. The first step is the complete kinematics characterization of the landslide ground surface, by evaluating the involved displacement and deformation patterns. A dense displacement Field can be obtained from comparison of a series of multi-temporal observations performed by means of terrestrial laser scanning. Subsequently, the strain Field can be computed from displacement vectors. In this paper, a modified least square technique is employed to compute the strain on the nodes of a regular grid (2D approach) or on the points of a digital terrain model (3D approach). Such a Computation takes into account the displacements, their spatial distribution, as well as the measurement and modelling errors. A scale factor is introduced in order to emphasize the contributions of the experimental points on the basis of their distance from each Computation point, and to recognize possible scale-depending behaviours. This method has been implemented in Matlab and applied on two landslides located in the northeastern Italian Alps (Lamosano and Perarolo di Cadore). The experiments show that different kinematics can be recognized, and the presence and influence of eventual discontinuities can be revealed.

Giordano Teza - One of the best experts on this subject based on the ideXlab platform.

  • grid_strain and grid_strain3 software packages for strain Field Computation in 2d and 3d environments
    2008
    Co-Authors: Giordano Teza, A Pesci, Antonio Galgaro
    Abstract:

    Two Matlab(TM) software packages for strain Field Computation, starting from displacements of experimental points (EPs), are here presented. In particular, grid_strain estimates the strain on the nodes of a regular planar grid, whereas grid_strain3 operates on the points of a digital terrain model (DTM). In both cases, the Computations are performed in a modified least-square approach, emphasizing the effects of nearest points. This approach allows users to operate at different scales of analysis by introducing a scale factor to reduce or also exclude points too far from grid nodes. The input data are displacements (or velocities) that can be provided by several techniques (e.g. GPS, total topographical station, terrestrial laser scanner). The analysis can be applied to both regional- and local-scale phenomena, to study tectonic crustal deformations (strain ~10^-^8-10^-^6) or rapid landslide collapses (10^-^4-10^2), and to characterize the kinematics of the studied system. Errors on strains and geometric significance of the results are also provided.

  • characterization of landslide ground surface kinematics from terrestrial laser scanning and strain Field Computation
    2008
    Co-Authors: Giordano Teza, A Pesci, Rinaldo Genevois, Antonio Galgaro
    Abstract:

    Assessment and mitigation of the risk induced by landslide activation need an appropriate phenomenon investigation, to obtain useful information about the failure processes. The first step is the complete kinematics characterization of the landslide ground surface, by evaluating the involved displacement and deformation patterns. A dense displacement Field can be obtained from comparison of a series of multi-temporal observations performed by means of terrestrial laser scanning. Subsequently, the strain Field can be computed from displacement vectors. In this paper, a modified least square technique is employed to compute the strain on the nodes of a regular grid (2D approach) or on the points of a digital terrain model (3D approach). Such a Computation takes into account the displacements, their spatial distribution, as well as the measurement and modelling errors. A scale factor is introduced in order to emphasize the contributions of the experimental points on the basis of their distance from each Computation point, and to recognize possible scale-depending behaviours. This method has been implemented in Matlab and applied on two landslides located in the northeastern Italian Alps (Lamosano and Perarolo di Cadore). The experiments show that different kinematics can be recognized, and the presence and influence of eventual discontinuities can be revealed.

A Pesci - One of the best experts on this subject based on the ideXlab platform.

  • grid_strain and grid_strain3 software packages for strain Field Computation in 2d and 3d environments
    2008
    Co-Authors: Giordano Teza, A Pesci, Antonio Galgaro
    Abstract:

    Two Matlab(TM) software packages for strain Field Computation, starting from displacements of experimental points (EPs), are here presented. In particular, grid_strain estimates the strain on the nodes of a regular planar grid, whereas grid_strain3 operates on the points of a digital terrain model (DTM). In both cases, the Computations are performed in a modified least-square approach, emphasizing the effects of nearest points. This approach allows users to operate at different scales of analysis by introducing a scale factor to reduce or also exclude points too far from grid nodes. The input data are displacements (or velocities) that can be provided by several techniques (e.g. GPS, total topographical station, terrestrial laser scanner). The analysis can be applied to both regional- and local-scale phenomena, to study tectonic crustal deformations (strain ~10^-^8-10^-^6) or rapid landslide collapses (10^-^4-10^2), and to characterize the kinematics of the studied system. Errors on strains and geometric significance of the results are also provided.

  • characterization of landslide ground surface kinematics from terrestrial laser scanning and strain Field Computation
    2008
    Co-Authors: Giordano Teza, A Pesci, Rinaldo Genevois, Antonio Galgaro
    Abstract:

    Assessment and mitigation of the risk induced by landslide activation need an appropriate phenomenon investigation, to obtain useful information about the failure processes. The first step is the complete kinematics characterization of the landslide ground surface, by evaluating the involved displacement and deformation patterns. A dense displacement Field can be obtained from comparison of a series of multi-temporal observations performed by means of terrestrial laser scanning. Subsequently, the strain Field can be computed from displacement vectors. In this paper, a modified least square technique is employed to compute the strain on the nodes of a regular grid (2D approach) or on the points of a digital terrain model (3D approach). Such a Computation takes into account the displacements, their spatial distribution, as well as the measurement and modelling errors. A scale factor is introduced in order to emphasize the contributions of the experimental points on the basis of their distance from each Computation point, and to recognize possible scale-depending behaviours. This method has been implemented in Matlab and applied on two landslides located in the northeastern Italian Alps (Lamosano and Perarolo di Cadore). The experiments show that different kinematics can be recognized, and the presence and influence of eventual discontinuities can be revealed.

Mabrouk Chabane - One of the best experts on this subject based on the ideXlab platform.

H Emdad - One of the best experts on this subject based on the ideXlab platform.

  • Complete flow Field Computation around an ACV (air-cushion vehicle) using 3D VOF with Lagrangian propagation in Computational domain
    2007
    Co-Authors: A H Nikseresht, M M Alishahi, H Emdad
    Abstract:

    In this study an algorithm and a 3D solver is developed to solve the flow Field around air-cushion vehicles (ACV) in vicinity of free surface. A single set of dimensionless equations is derived to handle both liquid and air phases in viscous 3D incompressible free surface flows in general curvilinear coordinates. The momentum equations are solved using the SIMPLE method in a staggered grid. The Lagrangian approach in the Computational domain is also applied in the context of the VOF method to resolve the free surface. To demonstrate the robustness and versatility of the code, an application of this method on the impact problem of a circular cylinder is presented that is compared to experimental, theoretical and other Computational results. In a 3D problem, the gravity-fill test is solved in both Cartesian and randomly generated curvilinear grid system. Comparison of results with the available experimental data and other numerical results is presented as well. At last, the code is applied to solve the two and three dimensional air and water flow Field around an ACV and the effects of several parameters including the under skirt pressure distribution, initial air gap and effect of Fr. number on the wave elevation and wave making drag are investigated. It is shown that the presented method and the code are, robust and accurate enough to produce complicated 3D flow Fields around ACV's.