1,970 research outputs found
Numerical simulation of detonation failure and re-initiation in bifurcated tubes
A numerical approach is developed to simulate detonation propagation, attenuation, failure and re-initiation in hydrogen–air mixture. The aim is to study the condition under which detonations may fail or re-initiate in bifurcated tubes which is important for risk assessment in industrial accidents. A code is developed to solve compressible, multidimensional, transient, reactive Navier–Stokes equations. An Implicit Large Eddy Simulation approach is used to model the turbulence. The code is developed and tested to ensure both deflagrations (when detonation fails) and detonations are simulated correctly. The code can correctly predict the flame properties as well as detonation dynamic parameters. The detonation propagation predictions in bifurcated tubes are validated against the experimental work of Wang et al. [1,2] and found to be in good agreement with experimental observations
Quantum Annealing for Computer Vision Minimization Problems
Computer Vision (CV) labelling algorithms play a pivotal role in the domain
of low-level vision. For decades, it has been known that these problems can be
elegantly formulated as discrete energy minimization problems derived from
probabilistic graphical models (such as Markov Random Fields). Despite recent
advances in inference algorithms (such as graph-cut and message-passing
algorithms), the resulting energy minimization problems are generally viewed as
intractable. The emergence of quantum computations, which offer the potential
for faster solutions to certain problems than classical methods, has led to an
increased interest in utilizing quantum properties to overcome intractable
problems. Recently, there has also been a growing interest in Quantum Computer
Vision (QCV), with the hope of providing a credible alternative or assistant to
deep learning solutions in the field. This study investigates a new Quantum
Annealing based inference algorithm for CV discrete energy minimization
problems. Our contribution is focused on Stereo Matching as a significant CV
labeling problem. As a proof of concept, we also use a hybrid quantum-classical
solver provided by D-Wave System to compare our results with the best classical
inference algorithms in the literature
Controllability and stability of 3D heat conduction equation in a submicroscale thin film
We obtain a closed form analytic solution for the Dual Phase Lagging equation. This equation is a linear, time-independent partial differential equation modeling the heat distribution in a thin film. The spatial domain is of micrometer and nanometer geometries. We show that the solution is described by a semigroup, and obtain a basis of eigenfunctions. The closure of the set of eigenvalues contains an interval, and so the theory on Riesz spectral operator of Curtain and Zwart cannot be applied directly. The exponential stability and the approximate controllability is shown
Activities Recognition and Fall Detection in Continuous Data Streams Using Radar Sensor
This student paper presents a Quadratic-kernel Support Vector Machine (SVM) based FMCW (Frequency Modulated Continuous Wave) radar system to recognize daily activities and detect fall accidents. Data collected in this work is divided into two different collection modes, namely, snapshots mode (different activities individually collected in isolation) and continuous activity mode (continuous streams of activities collected one after the other). For the continuous activity streams, a sliding window approach with 4s duration and 70% overlapping has achieved 84.7% classification accuracy and subsequent improvement of 2.6% has been proved by using Sequential Forward Selection (SFS) on six participants to identify an optimal feature set. A ‘tracking’ graph has been utilized to verify that the radar system can correctly identify falls as critical events among the other activities
Detection of anti-Neospora caninum antibodies in Iranian native cattle
ABSTRACT Neospora caninum is an Apicomplexan parasite which may cause abortion in cattle. This study investigated occurrences of antibodies against N. caninum in Iranian native cattle. From September 2010 to September 2011, blood samples (n=768) of native cows were collected randomly from different rural regions of Hamedan (n=400) and Kurdistan provinces (n=368) located to the western part of Iran. All the samples were evaluated for IgG antibodies against N. caninum using Enzyme Linked Immunosorbent Assay. The IgG antibodies to N. caninum were found in 14.2% (n=109/768) of serum samples (95% CI: 11.74 -16.66). There was a significant difference between seropositivity and abortion history (p<0.0001, OR=2.9), unlike to age groups (p=0.105). This is the first report of N. caninum infection in Iranian native cattle. In conclusion, N. caninum is an important factor in abortion in Iranian native cattle. Further comprehensive studies and designing control strategies for improving management in cattle farms are highly recommended
Gravitational traces of bumblebee gravity in metric-affine formalism
This work explores various manifestations of bumblebee gravity within the
metric--affine formalism. We investigate the impact of Lorentz violation
parameter, denoted as , on the modification of the \textit{Hawking}
temperature. Our calculations reveal that as increases, the values of the
\textit{Hawking} temperature attenuate. To examine the behavior of massless
scalar perturbations, specifically the \textit{quasinormal} modes, we employ
the WKB method. The transmission and reflection coefficients are determined
through our calculations. The outcomes indicate that a stronger
Lorentz--violating parameter results in slower damping oscillations of
gravitational waves. To comprehend the influence of the \textit{quasinormal}
spectrum on time--dependent scattering phenomena, we present a detailed
analysis of scalar perturbations in the time--domain solution. Additionally, we
conduct an investigation on shadows, revealing that larger values of
correspond to larger shadow radii. Lastly, we explore the concept of time delay
within this framework.Comment: 29 pages and 7 figure
- …