A client-server framework for the design of geo-location based augmented reality applications

We present a client-server framework for the development of mobile applications that use Augmented Reality (AR) to visualize geolocated data. Geo-information displays allow users to understand and respond effectively to the context in which the application is deployed. We provide a scalable and flexible architecture for the development and management of the client, the server and the data that are used by the applications. This architecture is based on the display of connected layers that represent structured information. The approach has been implemented in two case studies: the management of failures in electrical power lines, and to support hydrogeological monitoring

Mobile Augmented Reality for flood events management

The frequency of flood events worldwide has increased significantly over the past decades, and with it so has the need to employ information technologies able to help mobile workforces, both technicians and volunteers, during surveys in the emergency phases. In view of this, a client-server framework for the development of a mobile application that uses Augmented Reality (AR) was implemented. This platform, which increases visual perception of the real world merging additional information with the natural scene in real time, allows mobile workforces to more easily reach the most critical areas subject to flooding and rapidly make a decision on the level of flood protection. The performance of the prototype was evaluated on the Bradano river, located in the south-eastern Basilicata region (Italy), both in a real case study and in a simulated one. The obtained results show how the application represents an innovative tool compared to the existing ones, being it able to show, timely and continuously up-to-date, augmented information on various vulnerability scenarios during the emergency phases, helping both technical and non-technical operators to quickly intervene, containing or preventing secondary disasters, thus reducing deaths and injuries, and limiting the resulting economic losses and social disruption

Ambient Occlusion Baking via a Feed-Forward Neural Network

We present a feed-forward neural network approach for ambient occlusion baking in real-time rendering. The idea is based on implementing a multi-layer perceptron that allows a general encoding via regression and an efficient decoding via a simple GPU fragment shader. The non-linear nature of multi-layer perceptrons makes them suitable and effective for capturing nonlinearities described by ambient occlusion values. A multi-layer perceptron is also random-accessible, has a compact size, and can be evaluated efficiently on the GPU. We illustrate our approach of screen-space ambient occlusion based on neural network including its quality, size, and run-time speed

Applications of mobile augmented reality to water resources management

The present paper proposes a mobile prototype platform, based on Augmented Reality and multimedia smart-phone technology, which operates on a combination of real environment and computer-generated data in order to increase the human perception of a scene in real time. By enhancing visible details and displaying invisible or inexistent objects, this platform could improve water monitoring activities as well as the understanding of physical processes by technical and non-technical mobile workforces. At the same time, such a tool might support decision-makers in choosing strategies and actions aimed at forecasting, preventing, and mitigating environmental risks. A preliminary validation of the prototype performance was carried out in the field of water management, specifically for sample basin of Southern Italy. During the testing phase, this innovative application showed its ability to speed up field surveys, easily move around in unknown or remote places, and allow the employment of less-specialised users. These results could help reduce the time and costs of water monitoring activities, which would be perceived as essential by local administrators, contributing thus to the safeguard and the correct use of water resources

Transapical and Transfemoral Aortic Valve Implantation. Impact and General Considerations of both Approaches

Background: Transcatheter aortic valve implantation (TAVI) has emerged as a therapeutic option in inoperable or high surgical risk patients with severe symptomatic aortic stenosis. The transapical approach is an alternative access for patients with contraindications for the transfemoral access. Objective: The aim of this study was to evaluate the feasibility and reproducibility of transapical TAVI and compare the short and mid-term outcome with that of transfemoral TAVI. Methods: A cohort of 80 patients undergoing transapical (n=24) and transfemoral (n=56) TAVI was retrospectively evaluated. Procedure-related complications as defined by VARC-2 criteria, and short-term and mid-term mortality were analyzed and compared in both groups. Results: Patients in the transapical group were older (83.6 ± 5 vs. 80.0 ± 8.3; p = 0.04) and had greater prevalence of coronary artery disease (75 vs. 44%; p = 0.04) and peripheral vascular disease (37% vs. 16%; p = 0.01). Patients in the transapical group had lower fluoroscopy time (14.9 minutes ± 5.8 vs. 22.9 minutes ± 8.7; p = 0.001) and presented a non-significant trend toward greater requirement of dialysis after the procedure (12.5% vs. 1.8%, p = 0.13). Hospital stay was longer in the transapical group (13.6 ± 23 days vs. 7-2 ± 6.9 days, p = 0.05). Mortality at 30 days and one year was greater in the transapical group (20.8% vs. 5.4%; p = 0.03 and 25% vs. 8.9%; p = 0.04), respectively.  Conclusions: In our experience, transapical TAVI is a feasible and reproducible procedure for patients with severe symptomatic aortic stenosis unsuitable for transfemoral approach. Transapical access was associated with increased risk of mortality at 30 days, in agreement with several publications.Introducción: El implante valvular aórtico percutáneo (TAVI) ha surgido como una alternativa terapéutica en pacientes con estenosis aórtica grave sintomática inoperables o de elevado riesgo quirúrgico. El acceso transapical surge como alternativa para aquellos pacientes con contraindicación de implante valvular aórtico percutáneo transfemoral. Objetivo: Valorar la factibilidad y la reproducibilidad del implante valvular aórtico percutáneo transapical en nuestro centro y comparar la evolución a corto y mediano plazo con los pacientes sometidos a implante valvular aórtico percutáneo transfeoral. Material y métodos: Se evaluó una cohorte retrospectiva de 80 pacientes tratados con implante valvular aórtico percutáneo transapical (n = 24) y transfemoral (n = 56) en nuestro centro. Se compararon las complicaciones relacionadas con el procedimiento según las definiciones VARC-2, y se analizó la mortalidad a corto y mediano plazo entre ambos grupos. Resultados: Los pacientes del grupo transapical eran más añosos (83,6 ± 5 versus 80,0 ± 8,3; p = 0,04); presentaron mayor prevalencia de coronariopatía (el 75% versus el 44%; p = 0,04) y mayor prevalencia de vasculopatía periférica (el 37% versus el 16%; p = 0,01). El grupo transapical tuvo menor exposición a rayos X, (tiempo de fluoroscopia de 14,9 minutos ± 5,8 versus 22,9 minutos ± 8,7; p = 0,001); y una mayor tendencia a requerir diálisis luego del procedimiento (el 12,5% versus 1,8%, p = 0,13). El grupo transapical permaneció más tiempo internado (13,6 ± 23 días versus 7,2 ± 6,9 días, p = 0,05). La mortalidad a 30 días fue mayor en el grupo transapical (el 20,8% versus el 5,4%; p = 0,03) y al año (el 25% versus el 8,9%; p = 0,04). Conclusiones: En nuestra experiencia, el implante valvular aórtico percutáneo transapical es factible y puede ser realizado como un procedimiento reproducible para pacientes no aptos para el implante valvular aórtico percutáneo transfemoral. El acceso transapical se asoció con mayor mortalidad durante el seguimiento, particularmente en el período posoperatorio a 30 días, lo que coincide con varios reportes publicados