620 research outputs found
Computationally Efficient Implementation of Convolution-based Locally Adaptive Binarization Techniques
One of the most important steps of document image processing is binarization.
The computational requirements of locally adaptive binarization techniques make
them unsuitable for devices with limited computing facilities. In this paper,
we have presented a computationally efficient implementation of convolution
based locally adaptive binarization techniques keeping the performance
comparable to the original implementation. The computational complexity has
been reduced from O(W2N2) to O(WN2) where WxW is the window size and NxN is the
image size. Experiments over benchmark datasets show that the computation time
has been reduced by 5 to 15 times depending on the window size while memory
consumption remains the same with respect to the state-of-the-art algorithmic
implementation
A New Approach to Assess the Gastrocnemius Muscle Volume in Rodents Using Ultrasound; Comparison with the Gastrocnemius Muscle Index
Introduction: The purpose of this study was to determine the reliability and validity of a new non-invasive ultrasound technique to measure gastrocnemius muscle atrophy after nerve denervation in an animal model. Methods: In sixteen rodents an eight mm sciatic nerve gap was created. In the following 8 weeks, each week, two rodents were euthanized and the gastrocnemius muscle was examined using two different ultrasound systems and two investigators. The standardized ultrasound measurement protocol consisted of identifying pre-defined anatomical landmarks: 1) the fibula, 2) the fibular nerve, and 3) the junction between the most distal point of the semitendinosus muscle and gastrocnemius muscle. Consequently, we measured the muscle thickness as the length of the line between the fibula and the junction between the two muscles, perpendicular to the fibular nerve. After the ultrasound recording, the muscle mass was determined. Results: A steep decline of muscle weight of 24% was observed after one week. In the following weeks, the weight further decreased and then remained stable from 6 weeks onwards, resulting in a maximal muscle weight decrease of 82%. The correlation coefficient was >0.96 between muscle diameter and weight using both ultrasound systems. The inter-rater reliability was excellent for both devices on the operated side (ICC of 0.99 for both ultrasound systems) and good for the non-operated site (ICC's: 0.84 & 0.89). The difference between the muscle mass ratio and the muscle thickness ratio was not more than 5% with two outliers of approximately 13%. Discussion: We have developed an innovative, highly reliable technique for quantifying muscle atrophy after nerve injury. This technique allows serial measurements in the same animal over time. This is a significant advantage compared to the conventional technique for quantifying muscle atrophy, which requires sacrificing the animal
Deformation of Super Yang-Mills Theories in R-R 3-form Background
We study deformation of N=2 and N=4 super Yang-Mills theories, which are
obtained as the low-energy effective theories on the (fractional) D3-branes in
the presence of constant Ramond-Ramond 3-form background. We calculate the
Lagrangian at the second order in the deformation parameter from open string
disk amplitudes. In N=4 case we find that all supersymmetries are broken for
generic deformation parameter but part of supersymmetries are unbroken for
special case. We also find that classical vacua admit fuzzy sphere
configuration. In N=2 case we determine the deformed supersymmetries. We
rewrite the deformed Lagrangians in terms of N=1 superspace, where the
deformation is interpreted as that of coupling constants.Comment: v2: reference added, v3: published version in JHE
Measurement of K^+ \to \pi^0 \mu^+ \nu \gamma decay using stopped kaons
The K^+ \to \pi^0 \mu^+ \nu \gamma () decay has been
measured with stopped positive kaons at the KEK 12 GeV proton synchrotron. A
sample containing 125 events was obtained. The partial
branching ratio was found to be , which is in good agreement with theoretical predictions.Comment: 12 pages, 3 figures, to be published in Physics Letters
Instanton Calculus in R-R 3-form Background and Deformed N=2 Super Yang-Mills Theory
We study the ADHM construction of instantons in N=2 supersymmetric Yang-Mills
theory deformed in constant Ramond-Ramond (R-R) 3-form field strength
background in type IIB superstrings. We compare the deformed instanton
effective action with the effective action of fractional D3/D(-1) branes at the
orbifold singularity of C^2/Z_2 in the same R-R background. We find discrepancy
between them at the second order in deformation parameters, which comes from
the coupling of the translational zero modes of the D(-1)-branes to the R-R
background. We improve the deformed action by adding a term with space-time
dependent gauge coupling. Although the space-time action differs from the
action in the omega-background, both actions lead to the same instanton
equations of motion at the lowest order in gauge coupling.Comment: 27 pages, version to appear in JHE
Measurement of direct photon emission in decay using stopped positive kaons
The radiative decay () has
been measured with stopped positive kaons. A sample
containing 4k events was analyzed, and the branching ratio
of the direct photon emission process was determined to be . No interference pattern with internal
bremsstrahlung was observed.Comment: 12 pages, 6 figures, 2 tables, to be published in Phys. Lett.
Measurement of the Dalitz plot slope parameters for K- -> pi0 pi0 pi- decay using ISTRA+ detector
The Dalitz plot slope parameters g, h and k for the K- -> pi0 pi0 pi- decay
have been measured using in-flight decays detected with the ISTRA+ setup
operating in the 25 GeV negative secondary beam of the U-70 PS. About 252 K
events with four-momenta measured for the pi- and four involved photons were
used for the analysis. The values obtained g=0.627+/-0.004(stat)+/-0.010(syst),
h=0.046+/-0.004(stat)+/-0.012(syst), k=0.001+/-0.001(stat)+/-0.002(syst) are
consistent with the world averages dominated by K+ data, but have significantly
smaller errors.Comment: LaTeX, 10 pages, 8 eps-figures, update of IHEP 2002-1
p-wave phase shift and scattering length of Li
We have calculated the p-wave phase shifts and scattering length of Li.
For this we solve the partial wave Schr\"odinger equation and analyze the
validity of adopting the semiclassical solution to evaluate the constant
factors in the solution. Unlike in the wave case, the semiclassical
solution does not provide unique value of the constants. We suggest an
approximate analytic solution, which provides reliable results in special
cases. Further more, we also use the variable phase method to evaluate the
phase shifts. The p-wave scattering lengths of Cs and Cs are
calculated to validate the schemes followed. Based on our calculations, the
value of the wave scattering length of Li is .Comment: 10 figure
Measurement of ratio using stopped positive kaons
The ratio of the () and () decay widths, , has been measured with stopped positive kaons.
and samples containing 2.4 and 4.0 events, respectively, were analyzed. The
ratio was obtained to be
0.6710.007(stat.)0.008(syst.) calculating the detector acceptance by
a Monte Carlo simulation with the assumption of - universality in
decay. The coefficient of the dependent term of the form
factor was also determined to be
=0.0220.005(stat.)0.004(syst.).Comment: 12 pages, 6 figure
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