574 research outputs found
CoMoFoD #x2014; New database for copy-move forgery detection
Due to the availability of many sophisticated image processing tools, a digital image forgery is nowadays very often used. One of the common forgery method is a copy-move forgery, where part of an image is copied to another location in the same image with the aim of hiding or adding some image content. Numerous algorithms have been proposed for a copy-move forgery detection (CMFD), but there exist only few benchmarking databases for algorithms evaluation. We developed new database for a CMFD that consist of 260 forged image sets. Every image set includes forged image, two masks and original image. Images are grouped in 5 categories according to applied manipulation: translation, rotation, scaling, combination and distortion. Also, postprocessing methods, such as JPEG compression, blurring, noise adding, color reduction etc., are applied at all forged and original images. In this paper we present database organization and content, creation of forged images, postprocessing methods, and database testing. CoMoFoD database is available at http://www.vcl.fer.hr/comofodMinistry of Science, Education and Sport, China; project numbers: 036-0361630-1635 and 036-0361630-164
Fuzzy Dark Matter Dynamics and the Quasiparticle Hypothesis
Dark matter may be composed of ultra-light bosons whose de Broglie wavelength
in galaxies is of order 1 kpc. The standard model for this fuzzy dark matter
(FDM) is a complex scalar field that obeys the Schr\"odinger-Poisson equations.
The wavelike nature of FDM leads to fluctuations in the gravitational field
that can pump energy into the stellar components of a galaxy. Heuristic
arguments and theoretical analyses suggest that these fluctuations can be
modelled by replacing FDM with a system of quasiparticles (QPs). We test this
hypothesis by comparing self-consistent simulations of a Schr\"odinger field
with those using a system of QPs in one spatial dimension. Simulations of pure
FDM systems allow us to derive a phenomenological relation between the number
of QPs that is required to model FDM with a given de Broglie wavelength. We
also simulate systems of FDM and stars and find that the FDM pumps energy into
the stars whether it is described by QPs or a Schr\"odinger field with the FDM
adiabatically contracting and the stellar system adiabatically expanding.
However, we find that QPs overestimate dynamical heating.Comment: 9 pages, 10 figures, accepted for publication MNRA
The Status of a PA Endangered Bird- the Upland Sandpiper
The upland sandpiper (Bartramia Longuardia) has experienced a steep population decline in the northeastern U.S. since the mid-20th Century. In Pennsylvania it was found in less than 0.5% of atlas blocks during the Second Atlas of Breeding Birds in Pennsylvania project (2nd PBBA; 2004-09) and breeding was confirmed at only two locations. Due to continued declines and a small population size, the upland sandpiper was listed as PA endangered in 2012. During May 2012 the areas around 15 2nd PBBA upland sandpiper sightings were resurveyed by Gettysburg College students and volunteer birdwatchers. The aim was to establish whether the atlas records related to persisting populations. We used five-minute audio playback at up to 10 locations within 4km of the atlas sightings. A maximum of 19 pairs/calling male upland sandpipers were found across the state in 2012, most of them on or close to reclaimed surface mines. However, locating such a scarce species can be problematic, and it is still not known to what extent the species is under-reported. To help direct future surveys we analyzed data from the 2nd PBBA and the 2012 survey to produce a habitat suitability model for the upland sandpiper in Pennsylvania. We used a GIS framework to determine areas of suitable habitat and then stratified these by proximity to recent (2004-2012) upland sandpiper sightings. We recommend that our suitability model be used to establish a sampling protocol for more thorough statewide upland sandpiper survey every five years, in order that the speciesâ precarious status can be closely monitored
Studying Rate Control Methods for UHDTV Delivery Using HEVC
Since the early video coding standardisation efforts, rate control has been considered essential for almost any application, and has therefore been extensively studied. With the advent of improved video coding standards, such as the current stateof-the-art High Efficiency Video Coding (HEVC) standard, and the introduction of advanced flexible coding tools, previous Rate-Distortion (RD) models used for rate control have become obsolete. To address this issue, some rate control methods have been recently proposed specifically for HEVC which introduce many useful features, such as a robust correspondence between the rate and Lagrange multiplier . However, when applying these rate control methods on sequences in the new Ultra High Definition Television (UHDTV) format, degraded coding performance was observed. In this paper, an analysis of the state-of-the-art HEVC rate control method was performed and two directions for its improvement were evaluated. These improvements target frame-level bit-allocation and model parameter initialisation. When compared to the rate control method implemented in the HEVC reference software, these improvements result in reduced BDrate losses of 3:1% and 2:1%, versus the 8:8% provided by the reference algorithm. Moreover, the proposed improvements improve the accuracy in hitting the target bit-rate./p
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Interface polarization model for a 2-dimensional electron gas at the BaSnO3/LaInO3 interface
In order to explain the experimental sheet carrier density n2D at the interface of BaSnO3/LaInO3, we consider a model that is based on the presence of interface polarization in LaInO3 which extends over 2 pseudocubic unit cells from the interface and eventually disappears in the next 2 unit cells. Considering such interface polarization in calculations based on 1D Poisson-Schrödinger equations, we consistently explain the dependence of the sheet carrier density of BaSnO3/LaInO3 heterinterfaces on the thickness of the LaInO3 layer and the La doping of the BaSnO3 layer. Our model is supported by a quantitative analysis of atomic position obtained from high resolution transmission electron microscopy which evidences suppression of the octahedral tilt and a vertical lattice expansion in LaInO3 over 2â3 pseudocubic unit cells at the coherently strained interface
Sustained release of antimicrobials from double-layer nanofiber mats for local treatment of periodontal disease, evaluated using a new micro flow-through apparatus
Periodontal disease is a widespread chronic condition associated with degradation of periodontal tissues that requires more effective approaches for its treatment. Thus, the aim was to develop a nanodelivery system for local application of antimicrobials, with evaluation in vitro using a newly developed micro flow-through apparatus that simulates local in-vivo conditions in the periodontal pocket: small resting volume, and low gingival crevicular fluid flow rate. We successfully developed a double-layer nanofiber mat composed of a chitosan/ poly(ethylene) oxide nanofiber layer with 30% ciprofloxacin, and a poly(Δ-caprolactone) nanofiber layer with 5% metronidazole. The precisely designed composition enabled sustained in-vitro release of the antimicrobials according to their specific drug release mechanisms. The rate-limiting step of ciprofloxacin release was its own low solubility at pH 7.4, when there was excess of solid drug present in the delivery system. In contrast, sustained release of metronidazole was due to slow penetration of dissolution medium through the hydrophobic poly(Δ-caprolactone) nanofiber layer. The double-layer nanofiber mat developed showed antibacterial activity against Escherichia coli and Aggregatibacter actinomycetemcomitans based on plate antibiogram assays. The antimicrobial concentrations released from the nanofiber mats determined using the developed apparatus were above the minimal inhibitory concentrations against the periodontal pathogens for up to 7 days, which is valuable information for prediction of the efficacy of the nanodelivery system. Although this apparatus was specifically designed for characterization of formulations associated with treatments for periodontal disease, its applicability is much wide, as for development of any delivery system for application at target sites that have similar local conditions
Hospital treatment -is it affordable? A structured cost analysis of vaginal deliveries and planned caesarean sections
<p>Abstract</p> <p>Introduction</p> <p>The analysis of cost effectiveness in hospitals is as difficult as treating the patients properly. We are yet not able to answer the simple question of what costs are caused by a certain diagnosis and its treatment during an average hospital stay.</p> <p>Methods</p> <p>To answer some issues of the global problem of cost effectiveness during hospitalisation, we analysed the costs and the cost structure of a normal obstetrical hospital stay during an uncomplicated vaginal delivery and a planned caesarean section. Cost data was collected and summarized from the patients file, the hospital's computer system gathering all cost centres, known material expenses and expenses of non obstetrical medical services.</p> <p>Results</p> <p>For vaginal deliveries/planned caesareans we can calculate with a surplus of about 83 âŹ/1432 âŹ. About 45% of the summarized costs are calculated on a reliable database.</p> <p>Discussion</p> <p>The introduction of the DRG based clearing system in Germany has aggravated the discussion on cost effectiveness. Our meticulous work-up of expenses excluded personal precautionary costs and personnel costs of documentation because no tools are described to depict such costs. If we would add these costs to the known expenses of our study, we strongly suspect that hospital treatment of vaginal deliveries or planned caesarean sections is not cost effective.</p
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