Artículos de conferencia

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Browsing Artículos de conferencia by browse.metadata.categoriaods "14 Vida submarina"

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    Enabling new techniques in environmental assessment through multi-sensor hydrography
    (IEEE, 2016) E. J., Martin; D. W., Caress; H., Thomas; B., Hobson; R., Henthom; M., Risi; C. K., Paull; J. P., Barry; Troni Peralta, Giancarlo
    A suite of complementary survey tools aimed at producing 1-cm resolution bathymetric models co-registered with 2-mm pixel color photography has been assembled. The design goal is to produce quantitative documentation of both geological and biological features that will allow change over time to be assessed at vertical and lateral scales approaching one centimeter. The current suite of tools combines multibeam sonar, stereo cameras with dual xenon strobes, lidar, and an inertial navigation system (INS) aided by Doppler velocity log (DVL). This sensor package is mounted beneath remotely operated vehicles (ROV) and used to map the seafloor from low altitudes. A 100-m by 100-m survey can be accomplished in a single ROV dive. All surveys are conducted with scripted station-keeping control loops operating on the ROV, resulting in more efficient area coverage through tended automation. Fine scale surveys of a chemosynthetic biological community at 2850-m depth show that individual clams can be observed in both lidar bathymetry and photographic imagery. Repeat surveys over multiple years have been conducted in the morphologically active floor of Monterey Canyon. Comparison of these data resolve subtle transitions from depositional to erosional textures, and reveal the changes associated with frequent sediment transport events down the active canyon. The rocky, high relief environment of Sur Ridge offshore California hosts sponge and deep water coral habitats. Here the combination of acoustic and optic sensing proves particularly useful for quantitatively characterizing the benthic community. The multibeam sonar measures bathymetry without sensing soft animals, while the lidar measures a surface that includes these animals. Subtracting the multibeam bathymetry from the lidar bathymetry maps the locations and sizes of soft animals.
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    Examining the role of urban form in supporting rapid and safe tsunami evacuations: A multi-scalar analysis in Viña del Mar, Chile
    (2018) León, Jorge; Mokrani, Cyril; Catalán, Patricio; Cienfuegos Carrasco, Rodrigo Alberto; Femenías, Carolina
    Cities are increasingly becoming hot-spots for nature-originated disasters. While the role of the urban built environment in fostering disaster resilience has been recognized for some time, it has been difficult to translate this potential into practice. This is especially challenging in the case of rapid onset crises such as near-field tsunamis, when appropriate urban forms have to support the populations' ability to autonomously carry out safe and timely responses. In this respect, much of current research remains focused on large-scale elements of urban configuration (streets, squares, parks, etc.) through which people move during an emergency. In contrast, the critical micro-scale of evacuees' experiences within the built environment is not commonly examined. This paper addresses this shortfall through a macro- and micro-scale analysis of a near-field tsunami scenario affecting the city of Villa del Mar, Chile, including a mixed-methods approach that combines computer-based models and fieldwork. The results show significant macro-scale tsunami vulnerability throughout major areas of the city, which nonetheless could be mitigated by existing nearby high ground and an urban form that allows short evacuation times. However, micro-scale outcomes show comparatively deficient spatial conditions that during an emergency might lead to dangerous outcomes including bottlenecks, falls and panic. Vertical evacuation, in turn, is confirmed as a suitable option for reducing vulnerability, but further examination of each shelter's characteristics is required. (C) 2018 The Authors. Published by Elsevier Ltd.
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    Live ANDES: Mobile-Cloud Shared Workspace for Citizen Science and Wildlife Conservation
    (IEEE, 2015) Bonacic Salas, Cristián; Neyem, Andrés; Vásquez Guerra, Andrea Fernanda
    One of the weakest points of scientific research is the loss of data. A tiny fraction of the information generated onsite is published or released to public knowledge, and many useful studies end up stored in papers or emails without being utilized. Live ANDES is a mobile-cloud shared workspace designed to address this problem, promoting citizen science, data collection and analysis for wildlife conservation. It works by gathering geo-localized data provided by the scientific community, amateur naturalists, park rangers and people at large through web and mobile applications. Live ANDES offers filters, visualization and download options to work with existing data. Researchers can use this new information to identify species, ranges of distribution, and detect key habitat factors and potential threats to their conservation. Live ANDES is implemented using the Backend as a Service pattern on Microsoft Azure to manage the processing of the large amounts of data generated from sightings. It includes an API for mobile and desktop clients hosted in an Azure Virtual Machine, cloud storage and connection with external services to complement the existing information about recorded sightings. This paper discusses Live ANDES software design, architecture and a study case, in order to demonstrate an actual application of data management in the cloud and its impact on conservation.
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    Nearshore bathymetric inversion from video using a fully non-linear Boussinesq wave model
    (2011) Cienfuegos Carrasco, Rodrigo Alberto; Almar, R.; Birrien, F.; Castelle, B.; Catalán, P.; Michallet, H.
    This paper presents a new depth inversion methodology from video imagery. The strength of the method is the use of a fully non-linear Boussinesq wave model in combination with a very complete video-derived laboratory wave observation that includes period, celerity and wave height. Compared to the previous use of wave dispersion formulas, here the better description of wave dynamics substantially improves bathymetry estimation. For the considered laboratory case, error on bathymetry is as small as 8 % whereas other formulations, shallow water or non-linear derived solution can only attain 24 % and 14 %, respectively. More in-depth analysis on the error shows a fair sensitivity on video-derived breaker height and describes the large contribution of non-linearities. The recent possibility of using Serre's dispersion relation in combination with video-derived wave height provides a reasonable performance and should be further envisaged for one-dimensional depth inversion. Future extensions of this work involve the use of a two-dimensional Boussinesq model to include more hydrodynamics processes such as wave-driven circulation over three-dimensional surfzone sandbars.