On a continuation approach in Tikhonov regularization and its application in piecewise-constant parameter identification

We present a new approach to convexification of the Tikhonov regularization using a continuation method strategy. We embed the original minimization problem into a one-parameter family of minimization problems. Both the penalty term and the minimizer of the Tikhonov functional become dependent on a continuation parameter. In this way we can independently treat two main roles of the regularization term, which are stabilization of the ill-posed problem and introduction of the a priori knowledge. For zero continuation parameter we solve a relaxed regularization problem, which stabilizes the ill-posed problem in a weaker sense. The problem is recast to the original minimization by the continuation method and so the a priori knowledge is enforced. We apply this approach in the context of topology-to-shape geometry identification, where it allows to avoid the convergence of gradient-based methods to a local minima. We present illustrative results for magnetic induction tomography which is an example of PDE constrained inverse problem

Duffing-Type Oscillator with a Bounded from above Potential in the Presence of Saddle-Center Bifurcation and Singular Perturbation: Frequency Control

We analyze the dynamics of the forced singularly perturbed differential equations of Duffing’s type with a potential that is bounded from above. We explain the appearance of the large frequency nonlinear oscillations of the solutions. It is shown that the frequency can be controlled by a small parameter at the highest derivative

Note on F-Graph Construction

The center of an F-graph contains at least two vertices, and the distance between any two central vertices is equal to the radius. In this short note, we describe one way of constructing these graphs

The Impact of Air Resistance on the Fuel Consumption in Real Conditions within the Transport Operation

This paper presents the impact of air resistance (air resistance) on fuel consumption of the particular vehicle under real traffic conditions. In the introductory and subsequent part of the paper, the individual resistances influencing the moving vehicle are characterized. In the following chapter, the specific factors such as air resistance, driving speed, air temperature and air resistance coefficient in the context of their impact on fuel consumption of the particular vehicle are identified and described; as well as the comparisons of fuel consumption when the vehicle is moving on the highway with closed and open windows under different conditions of road traffic are performed

Measuring the Resistance of Tires for Passenger Vehicle against the Rolling and Sliding on Loading Area of the Flatbed Truck when Providing the Transport Services

This paper deals with the size of the forces affecting the vehicle during the transportation on a flatbed truck, railway wagon or container. It is necessary to secure the vehicle against these forces properly in order to prevent vehicle´s replacement. The laboratory measurements were performed in order to find out the size of coefficient of friction between the tire and the vehicle´s loading area. During the measurements, vehicle had different gears in order to determine to what extent the size of mechanical resistances affects the fixing and securing the vehicle against its replacement on the loading area. However, this paper does not propose the solution for securing the passenger vehicle on the loading area of a truck, railway wagon or container

An end-to-end in-flight calibration of Mini-EUSO detector

International audienceMini-EUSO is a wide Field-of-View (FoV, 44°) telescope currently in operation from a nadir-facing UV-transparent window in the Russian Zvezda module on the International Space Station (ISS). It is the first detector of the JEM-EUSO program deployed on the ISS, launched in August 2019. The main goal of Mini-EUSO is to measure the UV emissions from the ground and atmosphere, using an orbital platform. Mini-EUSO is mainly sensitive in the 290–430 nm bandwidth. Light is focused by a system of two Fresnel lenses of 25 cm diameter each on the Photo-Detector-Module (PDM), which consists of an array of 36 Multi-Anode Photomultiplier Tubes (MAPMTs), arranged in blocks of 2 × 2 called Elementary Cells (ECs), for a total of 2304 pixels working in photon counting mode, in three different time resolutions of 2.5 µs (defined as 1 Gate Time Unit, GTU), 320 µs and 40.96 ms operating in parallel. In the longest time scale, the data is continuously acquired to monitor the UV emission of the Earth. It is best suited for the observation of ground sources and therefore has been used for the observational campaigns of the ground-based UV flasher in order to perform an end-to-end calibration of Mini-EUSO. In this contribution, the assembled UV flasher, the operation of the field campaign and the analysis of the obtained data are presented. The result is compared with the overall effi ciency computed from the expectations which takes into account the atmospheric attenuation and the parametrisation of different effects such as the optics effi ciency, the MAPMT detection effi ciency, BG3 filter transmittance and the transparency of the ISS window

Implications of Mini-EUSO measurements for a space-based observation of UHECRs

International audienceMini-EUSO is the first mission of the JEM-EUSO program on board the International Space Station. It was launched in 2019 and it is currently located in the Russian section (Zvezda module) of the station and viewing our planet from a nadir-facing UV-transparent window. The instrument is based on the concept of the original JEM-EUSO mission and consists of an optical system employing two Fresnel lenses and a focal surface composed of 36 Multi-Anode Photomultiplier tubes, 64 channels each, for a total of 2304 channels with single photon counting sensitivity and an overall field of view of 44° × 44°. Mini-EUSO can map the night-time Earth in the near UV range (predominantly between 290 nm and 430 nm), with a spatial resolution of about 6.3 km and different temporal resolutions of 2.5 µ, 320 µs and 41 ms. Mini-EUSO observations are extremely important to better assess the potential of a space-based detector in studying Ultra-High Energy Cosmic Rays (UHECRs) such as K-EUSO and POEMMA. In this contribution we focus the attention on UV measurements, the observation of clouds and of certain categories of events that Mini-EUSO triggers with the shortest temporal resolution. We place them in the context of UHECR observations from space, namely the estimation of exposure and sensitivity to Extensive Air Showers