Video Enhancement and Dynamic Range Control of HDR Sequences for Automotive Applications

CMOS video cameras with high dynamic range (HDR) output are particularly suitable for driving assistance applications, where lighting conditions can strongly vary, going from direct sunlight to dark areas in tunnels. However, common visualization devices can only handle a low dynamic range, and thus a dynamic range reduction is needed. Many algorithms have been proposed in the literature to reduce the dynamic range of still pictures. Anyway, extending the available methods to video is not straightforward, due to the peculiar nature of video data. We propose an algorithm for both reducing the dynamic range of video sequences and enhancing its appearance, thus improving visual quality and reducing temporal artifacts. We also provide an optimized version of our algorithm for a viable hardware implementation on an FPGA. The feasibility of this implementation is demonstrated by means of a case study

Probabilistic analysis of the performance of barriers controlling the ignition of combustible gas in gas turbine air intakes

Nowadays, the frequent occurrence of hydrocarbon leaks underlies the need for investigating every possible contribution to the fire and explosion risk in the oil and gas industry. Hence, controlling the potential ignition sources is paramount for ensuring tolerable risk levels. Among potential ignitors, gas turbines (GT) are regarded as one of the main contributors when employed for mechanical-drive in the process area of offshore facilities even though their behaviour when acting as live sources has never been analysed in detail. This study aimed at investigating both the role that GTs play on the fire and explosion risk and the effect of further controlling ignition barrier elements by examining a real case of study. The Kamaleon FireEx™ – Risk and Barrier Management tool was used since this couples a CFD-based description of transient releases dispersion to the ignition probability modelling. After a first optimisation of the grid resolution, a selection procedure was developed to define a base case risk level. This result was analysed to highlight the time-window where ignitions occur and used as terms of comparison in the following sensitivity studies. First, the contribution that the installation of a GT carries along was quantified. The effect of an alternative ignition probability modelling, which underlies either a detailed representation of the GT behaviour when acting as an ignition source or the activation of an inert gas injecting system, was investigated thereafter. Results show the need for a quick response to obtain a risk reduction. Then, the influence of a shield wall that was built around the GT air-intakes was analysed. A covering effect was observed, which involved a reduction in the risk. Finally, since the wall introduced even a delaying effect, it was investigated whether this may combine with the alternative ignition model. Results showed a further risk reduction and the dominant role that physical barriers play in this context

Biomechanical approach to artistic gymnastics

openLa ginnastica artistica è uno sport che include azioni rapide e coordinate, caratterizzate da forza e dinamicità, per questo si presta ad essere valutata tramite un approccio biomeccanico. Spesso non basta osservare ad occhio nudo l’esecuzione di un elemento, ma sono necessari dati oggettivi per comprendere al meglio il movimento e i relativi errori. Questo elaborato vuole mostrare il vantaggio che può apportare l’analisi biomeccanica alle prestazioni di una ginnasta, attraverso evidenze sperimentali sul volteggio e il corpo libero. Tramite una revisione della letteratura scientifica a riguardo, sono state analizzate le variabili biomeccaniche della ribaltata, dello Tsukahara, dello Yurchenko e le tecniche di esecuzione degli avvitamenti, quali Cat Twist, Hula Hoop Twist e Tilt Twist. Sono stati identificati i metodi più efficaci mediante motion capture e modelli di simulazione computerizzata. L’allenatore, associando la tecnica ideale alle corrispondenti componenti cinematiche e dinamiche, può sviluppare programmi di allenamento specifici per ogni fase di un elemento, al fine di perfezionare la performance dell’atleta. Un’approfondita conoscenza delle forze applicate e degli angoli articolari, da parte degli allenatori e degli atleti, comporta inoltre una riduzione dei fattori di rischio di infortunio del sistema muscoloscheletrico.Artistic gymnastics is a sport that includes fast, co-ordinated actions characterised by strength and dynamism, which is why it lends itself to evaluation through a biomechanical approach. It is often not enough to observe the execution of an element with the naked eye, but objective data is required to better understand the movement and its errors. This paper aims to show the advantage that biomechanical analysis can bring to a gymnast's performance, through experimental evidence on vault and floor exercise. Through a review of the relevant scientific literature, the biomechanical variables of the Tsukahara, the Yurchenko and the techniques of performing vaults such as the Cat Twist, Hula Hoop Twist and Tilt Twist were analysed. The most effective methods were identified using motion capture and computer simulation models. By associating the ideal technique with the corresponding kinematic and dynamic components, the coach can develop specific training programmes for each phase of an element in order to perfect the athlete's performance. An in-depth knowledge of applied forces and joint angles, on the part of coaches and athletes, also leads to a reduction in risk factors for injuries of the musculoskeletal system