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Item type:Publication, Integration of non-destructive testing, numerical simulations, and simplified analytical tools for assessing the structural performance of historical adobe buildings(Elsevier, 2021-07-05)For existing structures, the development of seismic vulnerability studies requires the availability of information related to geometry, boundary conditions, material properties, and accumulated damage. In the case of historical constructions, modern conservation criteria recommend carrying out a comprehensive structural assessment that involves the use of concurrent experimental diagnosis complemented with numerical and analytical approaches for structural analysis. This paper presents a proposal for a comprehensive integration of these perspectives by the application of several tools for the seismic performance analysis of an iconic Andean historical adobe building: the 'San Pedro Apostol Church' located in Andahuaylillas, Southern Peru. In this church, several non-destructive techniques for geometrical and damage assessment were combined with structural exploration tools, nonlinear numerical modeling, and simplified analytical tools for performing predictive seismic analysis. The results indicate the feasibility of the integration of these techniques for studying existing earthen buildings and their capacity to properly predict observed damage in past earthquakes (i.e. failures of bell towers, façade walls, tympani, and triumphal arches). In particular, the analyses allowed the identification of high seismic vulnerability of the studied church in occasional earthquakes (earthquakes with a return period of 72 years) due to the activation of collapse mechanisms consisting of rocking of the façade walls and out-of-plane overturning of the lateral walls. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Comparison between clinical and computational method of surface measurements of skin ulcers caused by cutaneous leishmaniasis(Sociedad Espanola de Optica, 2022-01-01)Cutaneous leishmaniasis is a neglected disease caused by an intracellular parasite of the genus Leishmania. The implementation of new techniques for its monitoring is increasing. This article presents a methodology based on photogrammetry for the follow-up and evaluation of skin ulcers caused by cutaneous leishmaniasis. Leishmaniasis was experimentally inoculated into golden hamsters, which were analyzed during and after treatment for four months. The follow-up of the evolution of the disease is carried out by taking clinical (manual) and computational measurements. The clinical data were obtained using a caliper, measuring directly on the ulcerated area and performing calculations of geometric approximations with sizes similar to the ulcerated area (square and elliptical). Computational data was obtained by Agisoft PhotoScan software using a photogrammetry-based 3D reconstruction technique to model and extract information from the surface. Validation is carried out on the size of the cutaneous ulcerative areas under study, comparing the square and elliptical approximation of the area with that calculated by the software (total area of the 3D surface generated from the point cloud). This validation is performed by graphically comparing the trend in the variation of the ulcer area of each hamster, and an area correlation calculation (clinical vs computational measurements). As a result, 60% of the study population presents a strong correlation with a value of 0.8. We found that the computational technique allows physicians to provide a more reliable concept during ulcer healing follow-up - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Integration of NDT, 3D Parametric Modelling, and Nonlinear Numerical Analysis for the Seismic Assessment of a Vaulted Stone-Masonry Historical Building(Elsevier Ltd, 2023-07-01)This paper presents the integration of parametric modelling with NDT (NDT) and advanced numerical simulations for assessing the seismic response of an emblematic stone-masonry vaulted construction, the 16th-century church of the Society of Jesus located in Cusco, Peru. Revit parametric families allowed the creation of complex curved elements such as vaults and 3D geometrical models of the church based on a hybrid point cloud. The onsite survey results indicated that the main anomalies correspond to the presence of biological agents and cracking. In contrast, NDT allowed the estimation of the masonry material properties and the modal identification primarily of the towers. Finally, the application of pushover analyses allowed the estimation of the structure's maximum load capacity and post-peak behavoir. It was possible to determine that some collapse mechanisms (overturning of main façade and bell towers, and the generation of hinges in curved elements) can be activated in medium-strong earthquakes. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Eigen Paicas: A 3D Reconstruction of Entire Vessels Using Information of a Single Fragment and a Database(2025-10-01)Traditionally, fragments of ceramic vessels are collected diving an archaeological research project since they provide important pieces of evidence concerning cultural affiliation, dating, and other types of important information. However, complete vessels provide additional data such as food storage capacity and weight. A 3D reconstruction technique for reconstructing complete vessels based on fragments is proposed and applied to paicas, large ceramic containers from the Moche society of northern Peru. A database of profile contours, derived from the 3D models of 23 paicas, was established and used to reconstruct the shape of entire vessels from fragments using Principal Component Analysis (PCA) and the Simplex optimisation algorithm. Preliminary results from a group of four fragments provide good estimations with an average accuracy error of 14% and a precision error equal to 0%.9 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Enhanced Underwater 3-D Reconstruction: Case Study at Los Organos Reef Using 3dFeatureUp and 3dVisualAppUp(Institute of Electrical and Electronics Engineers Inc., 2026)In recent years, photogrammetry for tridimensional (3-D) reconstruction of underwater environments has gained significant interest, offering a nonintrusive approach to study and monitor aquatic ecosystems. However, underwater photogrammetry requires specialized equipment capable of capturing high-resolution images with adequate and uniform lighting. This article introduces two innovative methodologies, 3-D reconstruction based on Feature Enhancement (3dFeatureUp) and 3-D reconstruction based on Visual Appearance Enhancement (3dVisualAppUp), which are designed to enhance the accuracy and visual quality of 3-D underwater models. These methodologies incorporate novel algorithms for water image enhancement (WaterImgEnh) and water image restoration (WaterImgRest), aiming to address the challenges posed by underwater image acquisition such as light attenuation, color distortion, and visibility reduction. This approach is validated through the 3-D reconstruction of Los Organos Reef, located in Piura, Peru, employing a combination of standard and specialized underwater cameras along with a customized lighting system. The results demonstrate significant improvements in both the structural characteristics and visual appearance of the 3-D models, as compared to those generated by traditional methods or using specialized underwater cameras alone. The 3dFeatureUp method significantly enhances the structural features of the model by merging images from multiple cameras, while the 3dVisualAppUp methodology improves the visual quality of the models by correcting color imbalances and removing water effects.