African University of Science and Technology: Recent submissions
Now showing items 1381-1400 of 4828
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A molecular mechanism for the topographic alignment of convergent neural maps
(eLife Sciences Publications LtdeLife, 2017-03-14)Sensory processing requires proper alignment of neural maps throughout the brain. In the superficial layers of the superior colliculus of the midbrain, converging projections from retinal ganglion cells and neurons in ...
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On the number of non-zero elements of joint degree vectors
(Electronic Journal of CombinatoricsThe Electronic Journal of Combinatorics, 2017-03-31)Joint degree vectors give the number of edges between vertices of degree i and degree j for 1 ≤ i ≤ j ≤ n-1 in an n-vertex graph. We find lower and upper bounds for the maximum number of nonzero elements in a joint degree ...
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Nonlinear spectral image fusion
(Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 2017-01-01)© Springer International Publishing AG 2017. In this paper we demonstrate that the framework of nonlinear spectral decompositions based on total variation (TV) regularization is very well suited for image fusion as well ...
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The Tensor Algebra Compiler
(2017-02-17)Tensor and linear algebra is pervasive in data analytics and the physical sciences. Often the tensors, matrices or even vectors are sparse. Computing expressions involving a mix of sparse and dense tensors, matrices and ...
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Balanced semisimple filtrations for tilting modules
(American Mathematical SocietyRepresentation Theory, 2017-03-08)Let $ U_l$ be a quantum group at an $ l$th root of unity, obtained via Lusztig's divided powers construction. Many indecomposable tilting modules for $ U_l$ have been shown to have what we call a balanced semisimple ...
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The half plane UIPT is recurrent
(SpringerProbability Theory and Related Fields, 2017-03-07)We prove that the half plane version of the uniform infinite planar triangulation (UIPT) is recurrent. The key ingredients of the proof are a construction of a new full plane extension of the half plane UIPT, based on a ...
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Screened Coulomb interactions with non-uniform surface charge
(Royal Society PublishingProceedings of the Royal Society A: Mathematical, Physical and Engineering Science, 2017-03-22)The screened Coulomb interaction between a pair of infinite parallel planes with spatially varying surface charge is considered in the limit of small electrical potentials for arbitrary Debye lengths. A simple expression ...
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A Markov Model of a Limit Order Book: Thresholds, Recurrence, and Trading Strategies
We analyze a tractable model of a limit order book on short time scales, where the dynamics are driven by stochastic fluctuations between supply and demand. We establish the existence of a limiting distribution for the ...
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Secular evolution of eccentricity in protoplanetary discs with gap-opening planets
(Oxford University PressMonthly Notices of the Royal Astronomical Society, 2017-06)We explore the evolution of the eccentricity of an accretion disc perturbed by an embedded planet whose mass is sufficient to open a large gap in the disc. Various methods for representing the orbit-averaged motion of an ...
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Quasi-cyclic behaviour in non-linear simulations of the shear dynamo
(Oxford University PressMonthly Notices of the Royal Astronomical Society, 2017-02-17)The solar magnetic field displays features on a wide range of length-scales including spatial and temporal coherence on scales considerably larger than the chaotic convection that generates the field. Explaining how the ...
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3-manifolds everywhere
A random group contains many subgroups which are isomorphic to the fundamental group of a compact hyperbolic 3-manifold with totally geodesic boundary. These subgroups can be taken to be quasi-isometrically embedded. This ...
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Resonances in Coupled-Channel Scattering
Excited hadrons are seen as resonances in the scattering of lighter stable hadrons like π, K and η. Many decay into multiple final states necessitating coupled-channel analyses. Recently it has become possible to obtain ...
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Markov models for ocular fixation locations in the presence and absence of colour
In response to the 2015 Royal Statistical Society's statistical analytics challenge, we propose to model the fixation locations of the human eye when observing a still image by a Markov point process in R$_{2}$. Our approach ...
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The Galilean superstring
(SpringerJournal of High Energy Physics, 2017-02-21)The action for a Galilean superstring is found from a non-relativistic limit of the closed Green-Schwarz (GS) superstring; it has zero tension and provides an example of a massless super-Galilean system. A Wess-Zumino term ...
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Five vortex equations
(IOP PublishingJournal of Physics A: Mathematical and Theoretical, 2017-02-24)The Taubes equation for Abelian Higgs vortices is generalised to five distinct U(1) vortex equations. These include the Popov and Jackiw–Pi vortex equations, and two further equations. The Baptista metric, a conformal ...
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Collaborative Diagnosis of Over-Subscribed Temporal Plans
(2016-10-14)Over-subscription, that is, being assigned too many tasks or requirements that are too demanding, is commonly encountered in temporal planning problems. As human beings, we often want to do more than we can, ask for things ...
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SE-Sync: A Certifiably Correct Algorithm for Synchronization over the Special Euclidean Group
(2017-02-05)Many important geometric estimation problems naturally take the form of synchronization over the special Euclidean group: estimate the values of a set of unknown poses given noisy measurements of a subset of their pairwise ...
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The acoustic Green's function for swirling flow in a lined duct
(ElsevierJournal of Sound and Vibration, 2017-05-12)This paper considers the acoustic field inside an annular duct carrying mean axial and swirling flow and with either acoustically hard or lined walls. The particular aim is to compute the Green's function, which is required ...
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Mathematical imaging methods for mitosis analysis in live-cell phase contrast microscopy
(ElsevierMethods, 2017-02-15)In this paper we propose a workflow to detect and track mitotic cells in time-lapse microscopy image sequences. In order to avoid the requirement for cell lines expressing fluorescent markers and the associated phototoxicity, ...
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On the equal-mass limit of precessing black-hole binaries
(Institute of PhysicsClassical and Quantum Gravity, 2017-03-23)We analyze the inspiral dynamics of equal-mass precessing black-hole binaries using multi-timescale techniques. The orbit-averaged post-Newtonian evolutionary equations admit two constants of motion in the equal-mass limit, ...
