Search results for "aeronautics"
showing 10 items of 148 documents
ROAD project: Robotics for assisted diving
2014
The activities associated to underwater diving are of great importance in many areas. In the second half of the last century, diving technologies have greatly progressed, but diving is still characterized by significant risks, especially for professional divers who works at high depth, and limited practicability. The use of robotic systems and automatic procedures would allow, as in other situations where safety is of concern (for example, in case of hazardous works or in relation to hostile environments), a reliable monitoring and assessment of the physiological conditions of human operators during their activities. Moving from currently available technologies in underwater robotics, the R…
How to derive the analytical capacity model for not-conventional urban roundabouts
2008
The inapplicability of current methods for analyzing operations of urban not-conventional roundabouts (i.e. not referable to standard schemes) hampers seriously the assessment of their operational performances. Moreover, local constraints and the road network structure have produced lots of geometric layouts that make hard to propose an only framework to explain performances of not-conventional roundabouts. Also for these intersections it is hoped to have scientifically based methods to analyze operations with a proper reliability. Starting from these considerations, the paper shows the conceptual path followed to analyze operations at not-conventional roundabouts along an arterial of Paler…
An overview of safety effects on pedestrians at modern roundabouts
2011
Pedestrians are important users of the transportation system, but most guidelines have given them little importance in the geometric design of roads and intersections. In these cases it can be difficult for vehicles and pedestrians to share the road safely, particularly at intersections where vehicle-pedestrian conflicts (and the risk of vehicle–pedestrian crashes) can be a frequently recurring situation even with low pedestrian volume. In a sustainable safety vision road system planning and design must include engineering choices that help to improve the sharing of road space between vehicles and pedestrians, as well as for other vulnerable users. It is known that modern roundabouts are sa…
ESTCube-1 in-orbit experience and lessons learned
2015
ESTCube-1 is a student satellite project lead by the University of Tartu, Estonia, and supported by the European Space Agency (ESA) via Plan for European Cooperating States (PECS). Development of ESTCube-1 has been a collaborative effort with many international partners. The satellite is shown on Figure 1 [1].
Exergy recovery in regasification facilities – Cold utilization: A modular unit
2009
Abstract The paper deals with the problem of cold recovery for direct utilization both in the site of regasification facility and far from it. A modular LNG regasification unit is proposed having the regasification capacity of 2 billion standard cubic meters/year of gas. The modular plant is based on use of a power cycle working with ethane or ethylene which allows operation of cold energy transfer, contained in LNG to be regasified, in a range of temperatures suitable for multipurpose use of cold, reducing regasification process irreversibility. Some electric energy is produced by the power cycle, but the own mission of modular unit proposed is addressed to deliver cold suitable for indust…
Flood Detection On Low Cost Orbital Hardware
2019
Satellite imaging is a critical technology for monitoring and responding to natural disasters such as flooding. Despite the capabilities of modern satellites, there is still much to be desired from the perspective of first response organisations like UNICEF. Two main challenges are rapid access to data, and the ability to automatically identify flooded regions in images. We describe a prototypical flood segmentation system, identifying cloud, water and land, that could be deployed on a constellation of small satellites, performing processing on board to reduce downlink bandwidth by 2 orders of magnitude. We target PhiSat-1, part of the FSSCAT mission, which is planned to be launched by the …
Randomized Rx For Target Detection
2018
This work tackles the target detection problem through the well-known global RX method. The RX method models the clutter as a multivariate Gaussian distribution, and has been extended to nonlinear distributions using kernel methods. While the kernel RX can cope with complex clutters, it requires a considerable amount of computational resources as the number of clutter pixels gets larger. Here we propose random Fourier features to approximate the Gaussian kernel in kernel RX and consequently our development keep the accuracy of the nonlinearity while reducing the computational cost which is now controlled by an hyperparameter. Results over both synthetic and real-world image target detection…
Forrelation
2014
We achieve essentially the largest possible separation between quantum and classical query complexities. We do so using a property-testing problem called Forrelation, where one needs to decide whether one Boolean function is highly correlated with the Fourier transform of a second function. This problem can be solved using 1 quantum query, yet we show that any randomized algorithm needs Ω(√(N)log(N)) queries (improving an Ω(N[superscript 1/4]) lower bound of Aaronson). Conversely, we show that this 1 versus Ω(√(N)) separation is optimal: indeed, any t-query quantum algorithm whatsoever can be simulated by an O(N[superscript 1-1/2t])-query randomized algorithm. Thus, resolving an open questi…
Life-Cycle Costing Decision-Making Methodology and Urban Intersection Design: Modelling and Analysis for a Circular City
2021
The importance of being circular reflects one of the key concepts of the life-cycle thinking that promotes the sustainable production of goods and services. If it is true that the analysis of the product life-cycle is fundamental to optimize the use of resources and to plan for the future reduction of adverse effects on urban environment, it is also true that there are still several barriers covering conceptual and practical issues which hinder the building of shared approaches for the economic evaluation of infrastructure projects. The chapter presents a case study where the Life-Cycle Cost methodology is used to compare three alternative intersection projects based on their total life-cyc…
An EKF Based Method for Path Following in Turbulent Air
2017
An innovative use of the Extended Kalman Filter (EKF) is proposed to perform both accurate path following and adequate disturbance rejection in turbulent air. The tuned up procedure employs simultaneously two different EKF: the first one estimates gust disturbances, the second one estimates modified aircraft parameters. The first filter, by using measurements gathered in turbulent air, estimates both aircraft states and wind components. The second one, by using the estimated disturbances, obtains command laws that are able to reject disturbances. The predictor of the second EKF uses the estimated wind components to solve motion equations in turbulent air. Besides a set of unknown stability …