Higher Institute on Territorial Systems for Innovation
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Multipurpose UAV for search and rescue operations in mountain avalanche events
No full textThis paper presents a multipurpose UAV (unmanned aerial vehicle) for mountain rescue operations. The multi-rotors based flying platform and its embedded avionics are designed to meet environmental requirements for mountainous terrain such as low temperatures, high altitude and strong winds, assuring the capability of carrying different payloads (separately or together) such as: avalanche beacon (ARTVA) with automatic signal recognition and path following algorithms for the rapid location of snow-covered body; camera (visible and thermal) for search and rescue of missing persons on snow and in woods during the day or night; payload deployment to drop emergency kits or specific explosive cartridge for controlled avalanche detachment. The resulting small (less than 5 kg) UAV is capable of full autonomous flight (including take-off and landing) of a pre-programmed, or easily configurable, custom mission. Furthermore, the autopilot manages the sensors measurements (i.e. beacons or cameras) to update the flying mission automatically in flight. Specific functionalities such as terrain following were developed and implemented. Ground station programming of the UAV is not needed, except compulsory monitoring, as the rescue mission can be accomplished in a full automatic mode
Data-driven control of nonlinear systems: An on-line direct approach
No full textA data-driven method to design reference tracking controllers for nonlinear systems is presented. The technique does not derive explicitly a model of the system, rather it delivers directly a time-varying state-feedback controller by combining an on-line and an off-line scheme. Like in other on-line algorithms, the measurements collected in closed-loop operation are exploited to modify the controller in order to improve the tracking performance over time. At the same time, a predictable closed-loop behavior is guaranteed by making use of a batch of available data, which is a feature of off-line algorithms. The feedback controller is parameterized with kernel functions and the design approach exploits results in set membership identification and learning by projections. Under the assumptions of Lipschitz continuity and stabilizability of the system's dynamics, it is shown that if the initial batch of data is informative enough, then the resulting closed-loop system is guaranteed to be finite gain stable. In addition to the main theoretical properties of the approach, the design algorithm is demonstrated experimentally on a water tank system
IoT software infrastructure for Energy Management and Simulation in Smart Cities
No full textThis paper presents an IoT software infrastructure that enables energy management and simulation of new control policies in a city district. The proposed platform enables the interoperability and the correlation of (near-)real-time building energy profiles with environmental data from sensors as well as building and grid models. In a smart city context, this platform fulfills i) the integration of heterogeneous data sources at building and district level, and ii) the simulation of novel energy policies at district level aimed at the optimization of the energy usage accounting also for its impact on building comfort. The platform has been deployed in a real world district and a novel control policy for the heating distribution network has been developed and tested. Results are presented and discussed in the paper
Adaptive Approximated DCT Architectures for HEVC
No full textThis paper proposes a flexible and efficient implementation of the two-dimensional N-point Discrete Cosine Transform (DCT) for the High Efficiency Video Coding (HEVC) standard. The DCT is implemented through the Walsh-Hadamard Transform (WHT) followed by Givens rotations. This scheme is exploited to derive an adaptive algorithm, which allows to compute four different approximations ranging from the complete DCT to the WHT, by selectively skipping some rotations. The work shows the statistical analysis of the DCT usage and derives a pre-computation mechanism to adaptively skip rotations. Each approximation, referred to as operating mode, is characterized by a large saving of operations, at the expense of very small quality loss. Then, two 2D-DCT architectures are proposed: the first one is totally unfolded while the second one is folded. The two designs are finally synthesized with a 90-nm standard-cell library for a clock frequency of 250 MHz. Both architectures support real-time processing of 8K UHD video sequences at 64 and 26 fps respectively and show higher throughput and lower gate count compared to state-of-art implementations. Moreover, power saving ranging from 28% to 56% can be achieved by working within the proposed operating modes
Alternative Approaches to Magnetic Resonance-based Electric Properties Tomography and Local Specific Absorption Rate Estimation
No full textIn this paper, three electric properties tomography techniques based on magnetic resonance are applied to a realistic 2-D model problem representing the waist of an adult man. The capability of the inverse methods to recover the actual distribution of the electric properties is discussed and compared. In addition, the possibility to extend the methods to the estimate of local specific absorption rate of the radio frequency field generated in a magnetic resonance imaging, data concerning safety issues, is considered and compared
Synthetic biodegradable medical polyurethanes
No full textPolyurethanes (PURs) are a class of block copolymers synthesised from three different reagents: a polyol, a di- or multi-isocyanate, and a chain extender. Biodegradable PURs can be synthesised by properly selecting the building blocks with suitable properties for applications in regenerative medicine. The nature and relative amount of hard and soft segments affect the mechanical properties. PURs can be bulk or surface functionalised with biomimetic peptide sequences or natural polymers, affecting cell response and/or the biodegradation rate. PUR particles, fibres, and hydrogels can be designed with a suitable composition for drug encapsulation and controlled release. This chapter offers an overview of the chemistry of biodegradable and biocompatible PURs and reports their application as scaffolds for tissue engineering and carriers for drug delivery
Estimation accuracy vs. engineering significance of contact parameters for solid dampers
No full textOn the choice of contact parameters for the forced response calculation of a bladed disk with underplatform dampers
No full textDeformazione e frattura all'impatto
No full textLe munizioni perforanti (AP - Armor-Piercing Ammunition) sono una tipologia di proiettili impiegati allo scopo di perforare protezioni balistiche (armature o schermi difensivi) e sono generalmente costituite da un penetratore contenuto in un involucro (jaket). All'impatto tale involucro si distrugge, permettendo l'avanzamento del penetratore e la conseguente perforazione della barriera. Le munizioni perforanti più efficienti impiegano penetratori in lega di tungsteno (munizioni particolarmente costose) o in uranio impoverito (materiale particolarmente inquinante e pericoloso per la salute di chi opera sul luogo dell'avvenuto impatto), mentre quelle che utilizzano penetratori in acciaio, pur essendo più economiche e pulite delle precedenti, sono sicuramente molto meno efficienti. Nel presente studio sono descritti l'efficienza balistica, le dinamiche di deformazione ed i meccanismi di frattura all'impatto di tre penetratori sperimentali, prodotti con diversi acciai da utensili. I risultati balistici ottenuti con tali materiali sono inoltre comparati con quelli derivanti dall'impiego di acciaio a medio tenore di carbonio e di carburo di tungsteno cementato
