173 research outputs found
RIBBONS: Rapid Inpainting Based on Browsing of Neighborhood Statistics
Image inpainting refers to filling missing places in images using neighboring
pixels. It also has many applications in different tasks of image processing.
Most of these applications enhance the image quality by significant unwanted
changes or even elimination of some existing pixels. These changes require
considerable computational complexities which in turn results in remarkable
processing time. In this paper we propose a fast inpainting algorithm called
RIBBONS based on selection of patches around each missing pixel. This would
accelerate the execution speed and the capability of online frame inpainting in
video. The applied cost-function is a combination of statistical and spatial
features in all neighboring pixels. We evaluate some candidate patches using
the proposed cost function and minimize it to achieve the final patch.
Experimental results show the higher speed of 'Ribbons' in comparison with
previous methods while being comparable in terms of PSNR and SSIM for the
images in MISC dataset
A deep investigation of NiO and MnO through the first principle calculations and Monte Carlo simulations
In this study, we use Hubbard-Corrected density functional theory (DFT+)
to derive spin model Hamiltonians consisting of Heisenberg exchange
interactions up to the fourth nearest neighbors and bi-quadratic interactions.
We map the DFT+ results of several magnetic configurations to the Heisenberg
spin model Hamiltonian to estimate Heisenberg exchanges. We demonstrate that
the number of magnetic configurations should be at least twice the number of
exchange parameters to estimate exchange parameters correctly. To calculate
biquadratic interaction, we propose specific non-collinear magnetic
configurations that do not change the energy of the Heisenberg spin model. We
use classical Monte Carlo (MC) simulations to evaluate DFT+ results. We
obtain the temperature dependence of magnetic susceptibility and specific heat
to determine the Curie-Weiss and N\'eel temperatures. The MC simulations reveal
that although the biquadratic interaction can not change the N\'eel
temperature, it modifies the order parameter. We indicate that for a fair
comparison between classical MC simulations and experiments, we need to
consider the quantum effect by applying correction in classical MC
simulations
Image Inpainting by Hyperbolic Selection of Pixels for Two Dimensional Bicubic Interpolations
Image inpainting is a restoration process which has numerous applications.
Restoring of scanned old images with scratches, or removing objects in images
are some of inpainting applications. Different approaches have been used for
implementation of inpainting algorithms. Interpolation approaches only consider
one direction for this purpose. In this paper we present a new perspective to
image inpainting. We consider multiple directions and apply both
one-dimensional and two-dimensional bicubic interpolations. Neighboring pixels
are selected in a hyperbolic formation to better preserve corner pixels. We
compare our work with recent inpainting approaches to show our superior
results
Push Recovery of a Position-Controlled Humanoid Robot Based on Capture Point Feedback Control
In this paper, a combination of ankle and hip strategy is used for push
recovery of a position-controlled humanoid robot. Ankle strategy and hip
strategy are equivalent to Center of Pressure (CoP) and Centroidal Moment Pivot
(CMP) regulation respectively. For controlling the CMP and CoP we need a
torque-controlled robot, however most of the conventional humanoid robots are
position controlled. In this regard, we present an efficient way for
implementation of the hip and ankle strategies on a position controlled
humanoid robot. We employ a feedback controller to compensate the capture point
error. Using our scheme, a simple and practical push recovery controller is
designed which can be implemented on the most of the conventional humanoid
robots without the need for torque sensors. The effectiveness of the proposed
approach is verified through push recovery experiments on SURENA-Mini humanoid
robot under severe pushes
Efficacy of two entomopathogenic nematode species as potential biocontrol agents against the rosaceae longhorned beetle, Osphranteria coerulescens, under laboratory conditions.
Rosaceae longhorned beetle, Osphranteria coerulescens, is an important pest of fruit trees that attacks all fruit trees belonging to the family Rosaceae in cold regions of Iran. The potential efficacy of two species of entomopathogenic nematodes (EPN), Heterorhabditis bacteriophora and Steinernema carpocapsae, against last instar larvae of this pest was tested under Laboratory conditions. In plate assays, the larvae were susceptible to both EPN species but were more susceptible to S. carpocapsae (65.0-97.5% mortality) than H. bacteriophora (42.5-87.8%). Both nematode species were able to penetrate and reproduce within O. coerulescens larvae, but reproduction rate for H. bacteriophora was higher than those of S. carpocapsae; however, the penetration rate for S. carpocapsae was greater than H. bacteriophora. In a migration test on agar plate, S. carpocapsae showed negligible attraction to the pest or to Galleria mellonella cues. However, H. bacteriophora was strongly attracted to the sector of Petri dishes containing larvae. In a test using apricot tree branches, both species of EPN passed from mass frass of O. coerulescens larvae in the tip of the branches, penetrated into the larval galleries, and located and killed the larvae of O. coerulescens in their natural habitat deep inside the branches. Our findings provide the first insight into the biocontrol efficacy of EPN against O. coerulescens larvae, and highlight their potential for the control of this pest. Field experiments are needed to evaluate their potential under the environmental conditions in which rosaceae longhorned beetle larvae are found
Predicting Factors for the Communication between hydatid Cyst and Biliary Tract
Background: Hydatid cyst communicated with biliary tract increases the morbidity and mortality rates. Therefore, early detection and treatment are vital.Methods: From 96 patients undergone hydatid cyst surgery, 12 were excluded. The specifications, size, location, and position of the cyst, the condition of the cyst wall thickness, the caught lobe, cyst rupture, liver abscess, and the size of the inside and outside liver bile ducts were identified through computed tomography scanning. Age, gender, icterus, white blood cell (WBC) count, the total, direct, and indirect bilirubin, alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase were identified.Results: In 21 patients (13 men and 8 women), there was communication between the hydatid cyst and biliary tract; from them, 14 patients had icterus. There were significant differences between the size of the cyst, the levels of liver enzymes, bilirubin, and alkaline phosphatase, and WBC count in communicated and non-communicated hydatid cysts (P = 0.001). There were no significant differences between the two groups in terms of age, gender, location of the cysts in the liver, and the thickness of the liver.Conclusions: Only the cyst size and the level of bilirubin were the predicting factor for the communication between hydatid cyst and biliary tract
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