1,930 research outputs found

    Numerical simulation of detonation failure and re-initiation in bifurcated tubes

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    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

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    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

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    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

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    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

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    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

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    This work explores various manifestations of bumblebee gravity within the metric--affine formalism. We investigate the impact of Lorentz violation parameter, denoted as XX, on the modification of the \textit{Hawking} temperature. Our calculations reveal that as XX 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 XX correspond to larger shadow radii. Lastly, we explore the concept of time delay within this framework.Comment: 29 pages and 7 figure
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