66,080 research outputs found

    Scan to BIM for 3D reconstruction of the papal basilica of saint Francis in Assisi In Italy

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    The historical building heritage, present in the most of Italian cities centres, is, as part of the construction sector, a working potential, but unfortunately it requires planning of more complex and problematic interventions. However, policies to support on the existing interventions, together with a growing sensitivity for the recovery of assets, determine the need to implement specific studies and to analyse the specific problems of each site. The purpose of this paper is to illustrate the methodology and the results obtained from integrated laser scanning activity in order to have precious architectural information useful not only from the cultural heritage point of view but also to construct more operative and powerful tools, such as BIM (Building Information Modelling) aimed to the management of this cultural heritage. The Papal Basilica and the Sacred Convent of Saint Francis in Assisi in Italy are, in fact, characterized by unique and complex peculiarities, which require a detailed knowledge of the sites themselves to ensure visitor’s security and safety. For such a project, we have to take in account all the people and personnel normally present in the site, visitors with disabilities and finally the needs for cultural heritage preservation and protection. This aim can be reached using integrated systems and new technologies, such as Internet of Everything (IoE), capable of connecting people, things (smart sensors, devices and actuators; mobile terminals; wearable devices; etc.), data/information/knowledge and processes to reach the desired goals. The IoE system must implement and support an Integrated Multidisciplinary Model for Security and Safety Management (IMMSSM) for the specific context, using a multidisciplinary approach

    Video analysis of events within chemical sensor networks

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    This paper describes how we deploy video surveillance techniques to monitor the activities within a sensor network in order to detect environmental events. This approach combines video and sensor networks in a completely different way to what would be considered the norm. Sensor networks consist of a collection of autonomous, self-powered nodes which sample their environment to detect anything from chemical pollutants to atypical sound patterns which they report through an ad hoc network. In order to reduce power consumption nodes have the capacity to communicate with neighbouring nodes only. Typically these communications are via radio waves but in this paper the sensor nodes communicate to a base station through patterns emitted by LEDs and captured by a video camera. The LEDs are chemically coated to react to their environment and on doing so emit light which is then picked up by video analysis. There are several advantages to this approach and to demonstrate we have constructed a controlled test environment. In this paper we introduce and briefly describe this environment and the sensor nodes but focus mainly on the video capture, image processing and data visualisation techniques used to indicate these events to a user monitoring the network

    Experimental Synthetic Aperture Radar with Dynamic Metasurfaces

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    We investigate the use of a dynamic metasurface as the transmitting antenna for a synthetic aperture radar (SAR) imaging system. The dynamic metasurface consists of a one-dimensional microstrip waveguide with complementary electric resonator (cELC) elements patterned into the upper conductor. Integrated into each of the cELCs are two diodes that can be used to shift each cELC resonance out of band with an applied voltage. The aperture is designed to operate at K band frequencies (17.5 to 20.3 GHz), with a bandwidth of 2.8 GHz. We experimentally demonstrate imaging with a fabricated metasurface aperture using existing SAR modalities, showing image quality comparable to traditional antennas. The agility of this aperture allows it to operate in spotlight and stripmap SAR modes, as well as in a third modality inspired by computational imaging strategies. We describe its operation in detail, demonstrate high-quality imaging in both 2D and 3D, and examine various trade-offs governing the integration of dynamic metasurfaces in future SAR imaging platforms
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