Automatic Vehicle Identification is an important subsystem of Intelligent Transport Systems. One of the most common methods is the application of the licence plate recognition which is conducted in ...the following steps: detecting and extracting vehicles in dynamic scene, image pre-processing, licence plate localization, extracting characters from the licence plate and recognition of the individual character. In this paper, the operation of the Automatic licence plate identification module and multifunctional system for automatic traffic monitoring is presented. The preview of the algorithm operation is achieved by using Matlab (MathWorks) software and the corresponding appropriate Tools. The system has shown satisfactory results in recognizing licence plates and usefulness in the planned scope.Original Abstract: Automatska identifikacija prijevoznih sredstava vazan je podsustav inteligentnih transportnih sustava. Jedna od zastupljenijih metoda je primjena raspoznavanja registarskih plocica koja se provodi u sljedecim radnjama: otkrivanje i izdvajanje vozila u dinamickoj sceni, predobrada slike, odredivanje pozicije registarske plocice, izdvajanje karaktera s registarske plocice i raspoznavanje pojedinih karaktera. U ovome je radu prikazano djelovanje modula za automatsko prepoznavanje registarskih plocica kao visenamjenskog sustava za automatsko nadziranje cestovnog prometa. Prikaz rada algoritama ostvaren je koristenjem programske podrske Matlab (MathWorks) i pripadajucih odgovarajucih alata (tools). Sustav je pokazao zadovoljavajuce rezultate u prepoznavanju registarskih plocica vozila i mogucnosti upotrebe u predvidenom podrucju primjene.
With increasing requirements for reliability, availability, efficiency, effectiveness, productivity, and security of the system, the importance of diagnostics and maintenance is also increasing. ...E-maintenance as a leading concept for maintenance management has so far primarily involved the use of domain-specific technical language processing (TLP) techniques on historical case data. Due to its popularity, generative AI (GAI) with large language models (LLMs) is starting to be used more and more in various technical areas, thus starting to take an increasingly important place in diagnostics and maintenance. Starting from the fact that the rapid development of information and communication technologies (ICT) was the main factor in the emergence and development of the concept of e-maintenance, the importance of the potential more serious application of all forms of generative AI in the context is clear. This is especially pronounced in cases of difficult or impossible access to the location of components or an uncertain situation related to the type of process (e.g., nuclear, aeronautical, space, offshore). Autonomous vehicles, vessels, and aircraft (as an indispensable part of today's intelligent transport systems) are certainly a leading example of these cases. Regardless of the level of autonomy, these systems are extremely complex and difficult to maintain and represent a clear challenge for the application of new approaches. Therefore, the authors of the paper propose the use of middleware that would enable the integration of various GAI tools, algorithms, and models to increase the effectiveness of diagnostics and maintenance as close as possible to real-time. However, the exact extent of the possibilities and limitations of this approach has yet to be determined.
PSR B1259-63 is a gamma-ray binary system that hosts a pulsar in an eccentric orbit, with a 3.4 year period, around an O9.5Ve star. At orbital phases close to periastron passages, the system radiates ...bright and variable non-thermal emission. We report on an extensive VHE observation campaign conducted with the High Energy Stereoscopic System, comprised of ~100 hours of data taken from \(t_p-24\) days to \(t_p+127\) days around the system's 2021 periastron passage. We also present the timing and spectral analyses of the source. The VHE light curve in 2021 is consistent with the stacked light curve of all previous observations. Within the light curve, we report a VHE maximum at times coincident with the third X-ray peak first detected in the 2021 X-ray light curve. In the light curve -- although sparsely sampled in this time period -- we see no VHE enhancement during the second disc crossing. In addition, we see no correspondence to the 2021 GeV flare in the VHE light curve. The VHE spectrum obtained from the analysis of the 2021 dataset is best described by a power law of spectral index \(\Gamma = 2.65 \pm 0.04_{\text{stat}}\) \(\pm 0.04_{\text{sys}}\), a value consistent with the previous H.E.S.S. observations of the source. We report spectral variability with a difference of \(\Delta \Gamma = 0.56 ~\pm~ 0.18_{\text{stat}}\) \(~\pm~0.10_{\text{sys}}\) at 95% c.l., between sub-periods of the 2021 dataset. We also find a linear correlation between contemporaneous flux values of X-ray and TeV datasets, detected mainly after \(t_p+25\) days, suggesting a change in the available energy for non-thermal radiation processes. We detect no significant correlation between GeV and TeV flux points, within the uncertainties of the measurements, from \(\sim t_p-23\) days to \(\sim t_p+126\) days. This suggests that the GeV and TeV emission originate from different electron populations.
HESS J1813\(-\)178 is a very-high-energy \(\gamma\)-ray source spatially coincident with the young and energetic pulsar PSR J1813\(-\)1749 and thought to be associated with its pulsar wind nebula ...(PWN). Recently, evidence for extended high-energy emission in the vicinity of the pulsar has been revealed in the Fermi Large Area Telescope (LAT) data. This motivates revisiting the HESS J1813\(-\)178 region, taking advantage of improved analysis methods and an extended data set. Using data taken by the High Energy Stereoscopic System (H.E.S.S.) experiment and the Fermi-LAT, we aim to describe the \(\gamma\)-ray emission in the region with a consistent model, to provide insights into its origin. We performed a likelihood-based analysis on 32 hours of H.E.S.S. data and 12 years of Fermi-LAT data and fit a spectro-morphological model to the combined datasets. These results allowed us to develop a physical model for the origin of the observed \(\gamma\)-ray emission in the region. In addition to the compact very-high-energy \(\gamma\)-ray emission centered on the pulsar, we find a significant yet previously undetected component along the Galactic plane. With Fermi-LAT data, we confirm extended high-energy emission consistent with the position and elongation of the extended emission observed with H.E.S.S. These results establish a consistent description of the emission in the region from GeV energies to several tens of TeV. This study suggests that HESS J1813\(-\)178 is associated with a \(\gamma\)-ray PWN powered by PSR J1813\(-\)1749. A possible origin of the extended emission component is inverse Compton emission from electrons and positrons that have escaped the confines of the pulsar and form a halo around the PWN.
The radio galaxy M87 is a variable very-high energy (VHE) gamma-ray source, exhibiting three major flares reported in 2005, 2008, and 2010. Despite extensive studies, the origin of the VHE gamma-ray ...emission is yet to be understood. In this study, we investigate the VHE gamma-ray spectrum of M87 during states of high gamma-ray activity, utilizing 20.2\(\,\) hours the H.E.S.S. observations. Our findings indicate a preference for a curved spectrum, characterized by a log-parabola model with extra-galactic background light (EBL) model above 0.3\(\,\)TeV at the 4\(\sigma\) level, compared to a power-law spectrum with EBL. We investigate the degeneracy between the absorption feature and the EBL normalization and derive upper limits on EBL models mainly sensitive in the wavelength range 12.4$\,$$\mu\(m - 40\)\,$$\mu$m.
The Crab Nebula is a unique laboratory for studying the acceleration of electrons and positrons through their non-thermal radiation. Observations of very-high-energy \(\gamma\) rays from the Crab ...Nebula have provided important constraints for modelling its broadband emission. We present the first fully self-consistent analysis of the Crab Nebula's \(\gamma\)-ray emission between 1 GeV and \(\sim\)100 TeV, that is, over five orders of magnitude in energy. Using the open-source software package Gammapy, we combined 11.4 yr of data from the Fermi Large Area Telescope and 80 h of High Energy Stereoscopic System (H.E.S.S.) data at the event level and provide a measurement of the spatial extension of the nebula and its energy spectrum. We find evidence for a shrinking of the nebula with increasing \(\gamma\)-ray energy. Furthermore, we fitted several phenomenological models to the measured data, finding that none of them can fully describe the spatial extension and the spectral energy distribution at the same time. Especially the extension measured at TeV energies appears too large when compared to the X-ray emission. Our measurements probe the structure of the magnetic field between the pulsar wind termination shock and the dust torus, and we conclude that the magnetic field strength decreases with increasing distance from the pulsar. We complement our study with a careful assessment of systematic uncertainties.
SS 433 is a microquasar, a stellar binary system with collimated relativistic jets. We observed SS 433 in gamma rays using the High Energy Stereoscopic System (H.E.S.S.), finding an energy-dependent ...shift in the apparent position of the gamma-ray emission of the parsec-scale jets. These observations trace the energetic electron population and indicate the gamma rays are produced by inverse-Compton scattering. Modelling of the energy-dependent gamma-ray morphology constrains the location of particle acceleration and requires an abrupt deceleration of the jet flow. We infer the presence of shocks on either side of the binary system at distances of 25 to 30 parsecs and conclude that self-collimation of the precessing jets forms the shocks, which then efficiently accelerate electrons.
Most $\gamma$-ray detected active galactic nuclei are blazars with one of
their relativistic jets pointing towards the Earth. Only a few objects belong
to the class of radio galaxies or misaligned ...blazars. Here, we investigate the
nature of the object PKS 0625-354, its $\gamma$-ray flux and spectral
variability and its broad-band spectral emission with observations from
H.E.S.S., Fermi-LAT, Swift-XRT, and UVOT taken in November 2018. The H.E.S.S.
light curve above 200 GeV shows an outburst in the first night of observations
followed by a declining flux with a halving time scale of 5.9h. The
$\gamma\gamma$-opacity constrains the upper limit of the angle between the jet
and the line of sight to $\sim10^\circ$. The broad-band spectral energy
distribution shows two humps and can be well fitted with a single-zone
synchrotron self Compton emission model. We conclude that PKS 0625-354, as an
object showing clear features of both blazars and radio galaxies, can be
classified as an intermediate active galactic nuclei. Multi-wavelength studies
of such intermediate objects exhibiting features of both blazars and radio
galaxies are sparse but crucial for the understanding of the broad-band
emission of $\gamma$-ray detected active galactic nuclei in general.
In July 2021, PKS 1510-089 exhibited a significant flux drop in the high-energy gamma-ray (by a factor 10) and optical (by a factor 5) bands and remained in this low state throughout 2022. Similarly, ...the optical polarization in the source vanished, resulting in the optical spectrum being fully explained through the steady flux of the accretion disk and the broad-line region. Unlike the aforementioned bands, the very-high-energy gamma-ray and X-ray fluxes did not exhibit a significant flux drop from year to year. This suggests that the steady-state very-high-energy gamma-ray and X-ray fluxes originate from a different emission region than the vanished parts of the high-energy gamma-ray and optical jet fluxes. The latter component has disappeared through either a swing of the jet away from the line-of-sight or a significant drop in the photon production efficiency of the jet close to the black hole. Either change could become visible in high-resolution radio images.
PDF
