ath Asymptotic expansions of eigenvalues by both the Crouzeix-Raviart and enriched Crouzeix-Raviart elements. (arXiv:1902.09524v2 [math.NA] UPDATED) By arxiv.org Published On :: Asymptotic expansions are derived for eigenvalues produced by both the Crouzeix-Raviart element and the enriched Crouzeix--Raviart element. The expansions are optimal in the sense that extrapolation eigenvalues based on them admit a fourth order convergence provided that exact eigenfunctions are smooth enough. The major challenge in establishing the expansions comes from the fact that the canonical interpolation of both nonconforming elements lacks a crucial superclose property, and the nonconformity of both elements. The main idea is to employ the relation between the lowest-order mixed Raviart--Thomas element and the two nonconforming elements, and consequently make use of the superclose property of the canonical interpolation of the lowest-order mixed Raviart--Thomas element. To overcome the difficulty caused by the nonconformity, the commuting property of the canonical interpolation operators of both nonconforming elements is further used, which turns the consistency error problem into an interpolation error problem. Then, a series of new results are obtained to show the final expansions. Full Article
ath Weighted Moore-Penrose inverses of arbitrary-order tensors. (arXiv:1812.03052v3 [math.NA] UPDATED) By arxiv.org Published On :: Within the field of multilinear algebra, inverses and generalized inverses of tensors based on the Einstein product have been investigated over the past few years. In this paper, we explore the singular value decomposition and full-rank decomposition of arbitrary-order tensors using {it reshape} operation. Applying range and null space of tensors along with the reshape operation; we further study the Moore-Penrose inverse of tensors and their cancellation properties via the Einstein product. Then we discuss weighted Moore-Penrose inverses of arbitrary-order tensors using such product. Following a specific algebraic approach, a few characterizations and representations of these inverses are explored. In addition to this, we obtain a few necessary and sufficient conditions for the reverse-order law to hold for weighted Moore-Penrose inverses of arbitrary-order tensors. Full Article
ath Performance of the smallest-variance-first rule in appointment sequencing. (arXiv:1812.01467v4 [math.PR] UPDATED) By arxiv.org Published On :: A classical problem in appointment scheduling, with applications in health care, concerns the determination of the patients' arrival times that minimize a cost function that is a weighted sum of mean waiting times and mean idle times. One aspect of this problem is the sequencing problem, which focuses on ordering the patients. We assess the performance of the smallest-variance-first (SVF) rule, which sequences patients in order of increasing variance of their service durations. While it was known that SVF is not always optimal, it has been widely observed that it performs well in practice and simulation. We provide a theoretical justification for this observation by proving, in various settings, quantitative worst-case bounds on the ratio between the cost incurred by the SVF rule and the minimum attainable cost. We also show that, in great generality, SVF is asymptotically optimal, i.e., the ratio approaches 1 as the number of patients grows large. While evaluating policies by considering an approximation ratio is a standard approach in many algorithmic settings, our results appear to be the first of this type in the appointment scheduling literature. Full Article
ath ErdH{o}s-P'osa property of chordless cycles and its applications. (arXiv:1711.00667v3 [math.CO] UPDATED) By arxiv.org Published On :: A chordless cycle, or equivalently a hole, in a graph $G$ is an induced subgraph of $G$ which is a cycle of length at least $4$. We prove that the ErdH{o}s-P'osa property holds for chordless cycles, which resolves the major open question concerning the ErdH{o}s-P'osa property. Our proof for chordless cycles is constructive: in polynomial time, one can find either $k+1$ vertex-disjoint chordless cycles, or $c_1k^2 log k+c_2$ vertices hitting every chordless cycle for some constants $c_1$ and $c_2$. It immediately implies an approximation algorithm of factor $mathcal{O}(sf{opt}log {sf opt})$ for Chordal Vertex Deletion. We complement our main result by showing that chordless cycles of length at least $ell$ for any fixed $ellge 5$ do not have the ErdH{o}s-P'osa property. Full Article
ath Using hierarchical matrices in the solution of the time-fractional heat equation by multigrid waveform relaxation. (arXiv:1706.07632v3 [math.NA] UPDATED) By arxiv.org Published On :: This work deals with the efficient numerical solution of the time-fractional heat equation discretized on non-uniform temporal meshes. Non-uniform grids are essential to capture the singularities of "typical" solutions of time-fractional problems. We propose an efficient space-time multigrid method based on the waveform relaxation technique, which accounts for the nonlocal character of the fractional differential operator. To maintain an optimal complexity, which can be obtained for the case of uniform grids, we approximate the coefficient matrix corresponding to the temporal discretization by its hierarchical matrix (${cal H}$-matrix) representation. In particular, the proposed method has a computational cost of ${cal O}(k N M log(M))$, where $M$ is the number of time steps, $N$ is the number of spatial grid points, and $k$ is a parameter which controls the accuracy of the ${cal H}$-matrix approximation. The efficiency and the good convergence of the algorithm, which can be theoretically justified by a semi-algebraic mode analysis, are demonstrated through numerical experiments in both one- and two-dimensional spaces. Full Article
ath Compression, inversion, and approximate PCA of dense kernel matrices at near-linear computational complexity. (arXiv:1706.02205v4 [math.NA] UPDATED) By arxiv.org Published On :: Dense kernel matrices $Theta in mathbb{R}^{N imes N}$ obtained from point evaluations of a covariance function $G$ at locations ${ x_{i} }_{1 leq i leq N} subset mathbb{R}^{d}$ arise in statistics, machine learning, and numerical analysis. For covariance functions that are Green's functions of elliptic boundary value problems and homogeneously-distributed sampling points, we show how to identify a subset $S subset { 1 , dots , N }^2$, with $# S = O ( N log (N) log^{d} ( N /epsilon ) )$, such that the zero fill-in incomplete Cholesky factorisation of the sparse matrix $Theta_{ij} 1_{( i, j ) in S}$ is an $epsilon$-approximation of $Theta$. This factorisation can provably be obtained in complexity $O ( N log( N ) log^{d}( N /epsilon) )$ in space and $O ( N log^{2}( N ) log^{2d}( N /epsilon) )$ in time, improving upon the state of the art for general elliptic operators; we further present numerical evidence that $d$ can be taken to be the intrinsic dimension of the data set rather than that of the ambient space. The algorithm only needs to know the spatial configuration of the $x_{i}$ and does not require an analytic representation of $G$. Furthermore, this factorization straightforwardly provides an approximate sparse PCA with optimal rate of convergence in the operator norm. Hence, by using only subsampling and the incomplete Cholesky factorization, we obtain, at nearly linear complexity, the compression, inversion and approximate PCA of a large class of covariance matrices. By inverting the order of the Cholesky factorization we also obtain a solver for elliptic PDE with complexity $O ( N log^{d}( N /epsilon) )$ in space and $O ( N log^{2d}( N /epsilon) )$ in time, improving upon the state of the art for general elliptic operators. Full Article
ath Universal Coding and Prediction on Martin-L"of Random Points. (arXiv:2005.03627v1 [math.PR]) By arxiv.org Published On :: We perform an effectivization of classical results concerning universal coding and prediction for stationary ergodic processes over an arbitrary finite alphabet. That is, we lift the well-known almost sure statements to statements about Martin-L"of random sequences. Most of this work is quite mechanical but, by the way, we complete a result of Ryabko from 2008 by showing that each universal probability measure in the sense of universal coding induces a universal predictor in the prequential sense. Surprisingly, the effectivization of this implication holds true provided the universal measure does not ascribe too low conditional probabilities to individual symbols. As an example, we show that the Prediction by Partial Matching (PPM) measure satisfies this requirement. In the almost sure setting, the requirement is superfluous. Full Article
ath Seismic Shot Gather Noise Localization Using a Multi-Scale Feature-Fusion-Based Neural Network. (arXiv:2005.03626v1 [cs.CV]) By arxiv.org Published On :: Deep learning-based models, such as convolutional neural networks, have advanced various segments of computer vision. However, this technology is rarely applied to seismic shot gather noise localization problem. This letter presents an investigation on the effectiveness of a multi-scale feature-fusion-based network for seismic shot-gather noise localization. Herein, we describe the following: (1) the construction of a real-world dataset of seismic noise localization based on 6,500 seismograms; (2) a multi-scale feature-fusion-based detector that uses the MobileNet combined with the Feature Pyramid Net as the backbone; and (3) the Single Shot multi-box detector for box classification/regression. Additionally, we propose the use of the Focal Loss function that improves the detector's prediction accuracy. The proposed detector achieves an AP@0.5 of 78.67\% in our empirical evaluation. Full Article
ath A Local Spectral Exterior Calculus for the Sphere and Application to the Shallow Water Equations. (arXiv:2005.03598v1 [math.NA]) By arxiv.org Published On :: We introduce $Psimathrm{ec}$, a local spectral exterior calculus for the two-sphere $S^2$. $Psimathrm{ec}$ provides a discretization of Cartan's exterior calculus on $S^2$ formed by spherical differential $r$-form wavelets. These are well localized in space and frequency and provide (Stevenson) frames for the homogeneous Sobolev spaces $dot{H}^{-r+1}( Omega_{ u}^{r} , S^2 )$ of differential $r$-forms. At the same time, they satisfy important properties of the exterior calculus, such as the de Rahm complex and the Hodge-Helmholtz decomposition. Through this, $Psimathrm{ec}$ is tailored towards structure preserving discretizations that can adapt to solutions with varying regularity. The construction of $Psimathrm{ec}$ is based on a novel spherical wavelet frame for $L_2(S^2)$ that we obtain by introducing scalable reproducing kernel frames. These extend scalable frames to weighted sampling expansions and provide an alternative to quadrature rules for the discretization of needlet-like scale-discrete wavelets. We verify the practicality of $Psimathrm{ec}$ for numerical computations using the rotating shallow water equations. Our numerical results demonstrate that a $Psimathrm{ec}$-based discretization of the equations attains accuracy comparable to those of spectral methods while using a representation that is well localized in space and frequency. Full Article
ath A Reduced Basis Method For Fractional Diffusion Operators II. (arXiv:2005.03574v1 [math.NA]) By arxiv.org Published On :: We present a novel numerical scheme to approximate the solution map $smapsto u(s) := mathcal{L}^{-s}f$ to partial differential equations involving fractional elliptic operators. Reinterpreting $mathcal{L}^{-s}$ as interpolation operator allows us to derive an integral representation of $u(s)$ which includes solutions to parametrized reaction-diffusion problems. We propose a reduced basis strategy on top of a finite element method to approximate its integrand. Unlike prior works, we deduce the choice of snapshots for the reduced basis procedure analytically. Avoiding further discretization, the integral is interpreted in a spectral setting to evaluate the surrogate directly. Its computation boils down to a matrix approximation $L$ of the operator whose inverse is projected to a low-dimensional space, where explicit diagonalization is feasible. The universal character of the underlying $s$-independent reduced space allows the approximation of $(u(s))_{sin(0,1)}$ in its entirety. We prove exponential convergence rates and confirm the analysis with a variety of numerical examples. Further improvements are proposed in the second part of this investigation to avoid inversion of $L$. Instead, we directly project the matrix to the reduced space, where its negative fractional power is evaluated. A numerical comparison with the predecessor highlights its competitive performance. Full Article
ath Dirichlet spectral-Galerkin approximation method for the simply supported vibrating plate eigenvalues. (arXiv:2005.03433v1 [math.NA]) By arxiv.org Published On :: In this paper, we analyze and implement the Dirichlet spectral-Galerkin method for approximating simply supported vibrating plate eigenvalues with variable coefficients. This is a Galerkin approximation that uses the approximation space that is the span of finitely many Dirichlet eigenfunctions for the Laplacian. Convergence and error analysis for this method is presented for two and three dimensions. Here we will assume that the domain has either a smooth or Lipschitz boundary with no reentrant corners. An important component of the error analysis is Weyl's law for the Dirichlet eigenvalues. Numerical examples for computing the simply supported vibrating plate eigenvalues for the unit disk and square are presented. In order to test the accuracy of the approximation, we compare the spectral-Galerkin method to the separation of variables for the unit disk. Whereas for the unit square we will numerically test the convergence rate for a variable coefficient problem. Full Article
ath Error estimates for the Cahn--Hilliard equation with dynamic boundary conditions. (arXiv:2005.03349v1 [math.NA]) By arxiv.org Published On :: A proof of convergence is given for bulk--surface finite element semi-discretisation of the Cahn--Hilliard equation with Cahn--Hilliard-type dynamic boundary conditions in a smooth domain. The semi-discretisation is studied in the weak formulation as a second order system. Optimal-order uniform-in-time error estimates are shown in the $L^2$ and $H^1$ norms. The error estimates are based on a consistency and stability analysis. The proof of stability is performed in an abstract framework, based on energy estimates exploiting the anti-symmetric structure of the second order system. Numerical experiments illustrate the theoretical results. Full Article
ath Causal Paths in Temporal Networks of Face-to-Face Human Interactions. (arXiv:2005.03333v1 [cs.SI]) By arxiv.org Published On :: In a temporal network causal paths are characterized by the fact that links from a source to a target must respect the chronological order. In this article we study the causal paths structure in temporal networks of human face to face interactions in different social contexts. In a static network paths are transitive i.e. the existence of a link from $a$ to $b$ and from $b$ to $c$ implies the existence of a path from $a$ to $c$ via $b$. In a temporal network the chronological constraint introduces time correlations that affects transitivity. A probabilistic model based on higher order Markov chains shows that correlations that can invalidate transitivity are present only when the time gap between consecutive events is larger than the average value and are negligible below such a value. The comparison between the densities of the temporal and static accessibility matrices shows that the static representation can be used with good approximation. Moreover, we quantify the extent of the causally connected region of the networks over time. Full Article
ath Safe Data-Driven Distributed Coordination of Intersection Traffic. (arXiv:2005.03304v1 [math.OC]) By arxiv.org Published On :: This work addresses the problem of traffic management at and near an isolated un-signalized intersection for autonomous and networked vehicles through coordinated optimization of their trajectories. We decompose the trajectory of each vehicle into two phases: the provisional phase and the coordinated phase. A vehicle, upon entering the region of interest, initially operates in the provisional phase, in which the vehicle is allowed to optimize its trajectory but is constrained to guarantee in-lane safety and to not enter the intersection. Periodically, all the vehicles in their provisional phase switch to their coordinated phase, which is obtained by coordinated optimization of the schedule of the vehicles' intersection usage as well as their trajectories. For the coordinated phase, we propose a data-driven solution, in which the intersection usage order is obtained through a data-driven online "classification" and the trajectories are computed sequentially. This approach is computationally very efficient and does not compromise much on optimality. Moreover, it also allows for incorporation of "macro" information such as traffic arrival rates into the solution. We also discuss a distributed implementation of this proposed data-driven sequential algorithm. Finally, we compare the proposed algorithm and its two variants against traditional methods of intersection management and against some existing results in the literature by micro-simulations. Full Article
ath On the unique solution of the generalized absolute value equation. (arXiv:2005.03287v1 [math.NA]) By arxiv.org Published On :: In this paper, some useful necessary and sufficient conditions for the unique solution of the generalized absolute value equation (GAVE) $Ax-B|x|=b$ with $A, Bin mathbb{R}^{n imes n}$ from the optimization field are first presented, which cover the fundamental theorem for the unique solution of the linear system $Ax=b$ with $Ain mathbb{R}^{n imes n}$. Not only that, some new sufficient conditions for the unique solution of the GAVE are obtained, which are weaker than the previous published works. Full Article
ath Continuous maximal covering location problems with interconnected facilities. (arXiv:2005.03274v1 [math.OC]) By arxiv.org Published On :: In this paper we analyze a continuous version of the maximal covering location problem, in which the facilities are required to be interconnected by means of a graph structure in which two facilities are allowed to be linked if a given distance is not exceed. We provide a mathematical programming framework for the problem and different resolution strategies. First, we propose a Mixed Integer Non Linear Programming formulation, and derive properties of the problem that allow us to project the continuous variables out avoiding the nonlinear constraints, resulting in an equivalent pure integer programming formulation. Since the number of constraints in the integer programming formulation is large and the constraints are, in general, difficult to handle, we propose two branch-&-cut approaches that avoid the complete enumeration of the constraints resulting in more efficient procedures. We report the results of an extensive battery of computational experiments comparing the performance of the different approaches. Full Article
ath Structured inversion of the Bernstein-Vandermonde Matrix. (arXiv:2005.03251v1 [math.NA]) By arxiv.org Published On :: Bernstein polynomials, long a staple of approximation theory and computational geometry, have also increasingly become of interest in finite element methods. Many fundamental problems in interpolation and approximation give rise to interesting linear algebra questions. When attempting to find a polynomial approximation of boundary or initial data, one encounters the Bernstein-Vandermonde matrix, which is found to be highly ill-conditioned. Previously, we used the relationship between monomial Bezout matrices and the inverse of Hankel matrices to obtain a decomposition of the inverse of the Bernstein mass matrix in terms of Hankel, Toeplitz, and diagonal matrices. In this paper, we use properties of the Bernstein-Bezout matrix to factor the inverse of the Bernstein-Vandermonde matrix into a difference of products of Hankel, Toeplitz, and diagonal matrices. We also use a nonstandard matrix norm to study the conditioning of the Bernstein-Vandermonde matrix, showing that the conditioning in this case is better than in the standard 2-norm. Additionally, we use properties of multivariate Bernstein polynomials to derive a block $LU$ decomposition of the Bernstein-Vandermonde matrix corresponding to equispaced nodes on the $d$-simplex. Full Article
ath Mortar-based entropy-stable discontinuous Galerkin methods on non-conforming quadrilateral and hexahedral meshes. (arXiv:2005.03237v1 [math.NA]) By arxiv.org Published On :: High-order entropy-stable discontinuous Galerkin (DG) methods for nonlinear conservation laws reproduce a discrete entropy inequality by combining entropy conservative finite volume fluxes with summation-by-parts (SBP) discretization matrices. In the DG context, on tensor product (quadrilateral and hexahedral) elements, SBP matrices are typically constructed by collocating at Lobatto quadrature points. Recent work has extended the construction of entropy-stable DG schemes to collocation at more accurate Gauss quadrature points. In this work, we extend entropy-stable Gauss collocation schemes to non-conforming meshes. Entropy-stable DG schemes require computing entropy conservative numerical fluxes between volume and surface quadrature nodes. On conforming tensor product meshes where volume and surface nodes are aligned, flux evaluations are required only between "lines" of nodes. However, on non-conforming meshes, volume and surface nodes are no longer aligned, resulting in a larger number of flux evaluations. We reduce this expense by introducing an entropy-stable mortar-based treatment of non-conforming interfaces via a face-local correction term, and provide necessary conditions for high-order accuracy. Numerical experiments in both two and three dimensions confirm the stability and accuracy of this approach. Full Article
ath Multi-dimensional Avikainen's estimates. (arXiv:2005.03219v1 [math.PR]) By arxiv.org Published On :: Avikainen proved the estimate $mathbb{E}[|f(X)-f(widehat{X})|^{q}] leq C(p,q) mathbb{E}[|X-widehat{X}|^{p}]^{frac{1}{p+1}} $ for $p,q in [1,infty)$, one-dimensional random variables $X$ with the bounded density function and $widehat{X}$, and a function $f$ of bounded variation in $mathbb{R}$. In this article, we will provide multi-dimensional analogues of this estimate for functions of bounded variation in $mathbb{R}^{d}$, Orlicz-Sobolev spaces, Sobolev spaces with variable exponents and fractional Sobolev spaces. The main idea of our arguments is to use Hardy-Littlewood maximal estimates and pointwise characterizations of these function spaces. We will apply main statements to numerical analysis on irregular functionals of a solution to stochastic differential equations based on the Euler-Maruyama scheme and the multilevel Monte Carlo method, and to estimates of the $L^{2}$-time regularity of decoupled forward-backward stochastic differential equations with irregular terminal conditions. Full Article
ath Conley's fundamental theorem for a class of hybrid systems. (arXiv:2005.03217v1 [math.DS]) By arxiv.org Published On :: We establish versions of Conley's (i) fundamental theorem and (ii) decomposition theorem for a broad class of hybrid dynamical systems. The hybrid version of (i) asserts that a globally-defined "hybrid complete Lyapunov function" exists for every hybrid system in this class. Motivated by mechanics and control settings where physical or engineered events cause abrupt changes in a system's governing dynamics, our results apply to a large class of Lagrangian hybrid systems (with impacts) studied extensively in the robotics literature. Viewed formally, these results generalize those of Conley and Franks for continuous-time and discrete-time dynamical systems, respectively, on metric spaces. However, we furnish specific examples illustrating how our statement of sufficient conditions represents merely an early step in the longer project of establishing what formal assumptions can and cannot endow hybrid systems models with the topologically well characterized partitions of limit behavior that make Conley's theory so valuable in those classical settings. Full Article
ath An Optimal Control Theory for the Traveling Salesman Problem and Its Variants. (arXiv:2005.03186v1 [math.OC]) By arxiv.org Published On :: We show that the traveling salesman problem (TSP) and its many variants may be modeled as functional optimization problems over a graph. In this formulation, all vertices and arcs of the graph are functionals; i.e., a mapping from a space of measurable functions to the field of real numbers. Many variants of the TSP, such as those with neighborhoods, with forbidden neighborhoods, with time-windows and with profits, can all be framed under this construct. In sharp contrast to their discrete-optimization counterparts, the modeling constructs presented in this paper represent a fundamentally new domain of analysis and computation for TSPs and their variants. Beyond its apparent mathematical unification of a class of problems in graph theory, the main advantage of the new approach is that it facilitates the modeling of certain application-specific problems in their home space of measurable functions. Consequently, certain elements of economic system theory such as dynamical models and continuous-time cost/profit functionals can be directly incorporated in the new optimization problem formulation. Furthermore, subtour elimination constraints, prevalent in discrete optimization formulations, are naturally enforced through continuity requirements. The price for the new modeling framework is nonsmooth functionals. Although a number of theoretical issues remain open in the proposed mathematical framework, we demonstrate the computational viability of the new modeling constructs over a sample set of problems to illustrate the rapid production of end-to-end TSP solutions to extensively-constrained practical problems. Full Article
ath Avoiding 5/4-powers on the alphabet of nonnegative integers. (arXiv:2005.03158v1 [math.CO]) By arxiv.org Published On :: We identify the structure of the lexicographically least word avoiding 5/4-powers on the alphabet of nonnegative integers. Specifically, we show that this word has the form $p au(varphi(z) varphi^2(z) cdots)$ where $p, z$ are finite words, $varphi$ is a 6-uniform morphism, and $ au$ is a coding. This description yields a recurrence for the $i$th letter, which we use to prove that the sequence of letters is 6-regular with rank 188. More generally, we prove $k$-regularity for a sequence satisfying a recurrence of the same type. Full Article
ath An augmented Lagrangian preconditioner for implicitly-constituted non-Newtonian incompressible flow. (arXiv:2005.03150v1 [math.NA]) By arxiv.org Published On :: We propose an augmented Lagrangian preconditioner for a three-field stress-velocity-pressure discretization of stationary non-Newtonian incompressible flow with an implicit constitutive relation of power-law type. The discretization employed makes use of the divergence-free Scott-Vogelius pair for the velocity and pressure. The preconditioner builds on the work [P. E. Farrell, L. Mitchell, and F. Wechsung, SIAM J. Sci. Comput., 41 (2019), pp. A3073-A3096], where a Reynolds-robust preconditioner for the three-dimensional Newtonian system was introduced. The preconditioner employs a specialized multigrid method for the stress-velocity block that involves a divergence-capturing space decomposition and a custom prolongation operator. The solver exhibits excellent robustness with respect to the parameters arising in the constitutive relation, allowing for the simulation of a wide range of materials. Full Article
ath Optimally Convergent Mixed Finite Element Methods for the Stochastic Stokes Equations. (arXiv:2005.03148v1 [math.NA]) By arxiv.org Published On :: We propose some new mixed finite element methods for the time dependent stochastic Stokes equations with multiplicative noise, which use the Helmholtz decomposition of the driving multiplicative noise. It is known [16] that the pressure solution has a low regularity, which manifests in sub-optimal convergence rates for well-known inf-sup stable mixed finite element methods in numerical simulations, see [10]. We show that eliminating this gradient part from the noise in the numerical scheme leads to optimally convergent mixed finite element methods, and that this conceptual idea may be used to retool numerical methods that are well-known in the deterministic setting, including pressure stabilization methods, so that their optimal convergence properties can still be maintained in the stochastic setting. Computational experiments are also provided to validate the theoretical results and to illustrate the conceptional usefulness of the proposed numerical approach. Full Article
ath Strong replica symmetry in high-dimensional optimal Bayesian inference. (arXiv:2005.03115v1 [math.PR]) By arxiv.org Published On :: We consider generic optimal Bayesian inference, namely, models of signal reconstruction where the posterior distribution and all hyperparameters are known. Under a standard assumption on the concentration of the free energy, we show how replica symmetry in the strong sense of concentration of all multioverlaps can be established as a consequence of the Franz-de Sanctis identities; the identities themselves in the current setting are obtained via a novel perturbation of the prior distribution of the signal. Concentration of multioverlaps means that asymptotically the posterior distribution has a particularly simple structure encoded by a random probability measure (or, in the case of binary signal, a non-random probability measure). We believe that such strong control of the model should be key in the study of inference problems with underlying sparse graphical structure (error correcting codes, block models, etc) and, in particular, in the derivation of replica symmetric formulas for the free energy and mutual information in this context. Full Article
ath Two-Grid Deflated Krylov Methods for Linear Equations. (arXiv:2005.03070v1 [math.NA]) By arxiv.org Published On :: An approach is given for solving large linear systems that combines Krylov methods with use of two different grid levels. Eigenvectors are computed on the coarse grid and used to deflate eigenvalues on the fine grid. GMRES-type methods are first used on both the coarse and fine grids. Then another approach is given that has a restarted BiCGStab (or IDR) method on the fine grid. While BiCGStab is generally considered to be a non-restarted method, it works well in this context with deflating and restarting. Tests show this new approach can be very efficient for difficult linear equations problems. Full Article
ath How Does the IMPACT Baseline Test for Athletes Really Work? By feedproxy.google.com Published On :: Thu, 23 Jan 2014 00:00:00 EST Retired Soccer Star Briana Scurry describes how the computerized baseline test works and how it is used for athletes who have sustained a concussion. Full Article video
ath Chronic Traumatic Encephalopathy (CTE) in Amateur Athletes By feedproxy.google.com Published On :: Thu, 03 Dec 2015 00:00:00 EST A new study suggests that vulnerability to CTE is not limited to professional athletes. Full Article video
ath CTE pathology in a neurodegenerative disorders brain bank By feedproxy.google.com Published On :: Thu, 03 Dec 2015 00:00:00 EST Full Article page
ath Teen athletes sandbag concussion tests to stay in the game By feedproxy.google.com Published On :: Thu, 04 Feb 2016 00:00:00 EST What happens when the drive to play outweighs the potential risk of injury? Some high school athletes are finding ways around the precautions coaching and medical staff take to ensure their safety. Full Article video
ath New Report Details Path to 100% Renewables by 2050 By feedproxy.google.com Published On :: Tue, 22 Sep 2015 10:01:23 +0000 By Jon Queally Common Dreams Greenpeace says world leaders must not let the fossil fuel industry stand in the way of the necessary—and attainable—transition to a clean and safe energy future With scientists and experts from around the world telling … Continue reading → Full Article Solar Greenpeace Paris climate talks renewable energy
ath North Idaho Rep. Heather Scott reaps the glory — and the consequences — of being one of Matt Shea's biggest allies By www.inlander.com Published On :: Thu, 06 Feb 2020 01:30:00 -0800 At these gatherings in northeast Washington, the jackboot of tyranny is always said to be descending, the hand of the federal government always inches away from stealing your guns, your land, your freedom to speak or to pray.… Full Article News/Local News
ath A father sees his son for the final time through a pane of glass at a Lewiston nursing home By www.inlander.com Published On :: Fri, 24 Apr 2020 14:31:41 -0700 Monty Spears didn't know it at the time, but the last time he'd see his father would be through the window at the Life Care Center of Lewiston.… Full Article News/Local News
ath Noah Baumbach's great Marriage Story finds comedy and empathy in the details of a painful divorce By www.inlander.com Published On :: Thu, 05 Dec 2019 01:30:00 -0800 [IMAGE-1] Noah Baumbach's Marriage Story begins as its central marriage is coming to an end. Our two protagonists are fiercely independent, articulate, opinionated creative types: Charlie (Adam Driver) is the director of an avant-garde theater troupe in New York City; Nicole (Scarlett Johansson) is an actress and one of his primary collaborators.… Full Article Film/Film News
ath Don't expect any socially distanced Zags games in the Kennel next year, and other thoughts from Gonzaga Athletic Director Mike Roth's online Q&A By www.inlander.com Published On :: Wed, 29 Apr 2020 14:03:00 -0700 Gonzaga Athletic Director Mike Roth took to the Zoom online meeting app Wednesday for a lengthy chat with members of the school community, fans and media to answer questions about college sports in the era of COVID-19. Like so many things regarding the coronavirus, there are a lot of hopes for a rapid return to normalcy — all of them couched in the reality that none of us really know how the pandemic is going to affect our lives three months from now, or six months down the line.… Full Article Sports
ath Kathy Valentine talks about her deeply personal memoir and life in the Go-Go's By www.inlander.com Published On :: Thu, 30 Apr 2020 04:00:00 -0700 Virtually every musician starts out trying to copy their heroes.… Full Article Arts & Culture
ath White House projects COVID-19 death toll of 3,000 people per day, Washington casinos weigh reopening, and other headlines By www.inlander.com Published On :: Mon, 04 May 2020 09:27:30 -0700 ON INLANDER.COM WORLD: Roughly two weeks after Canada's deadliest mass shooting, Prime Minister Justin Trudeau introduced an immediate ban on what he called “military-style assault weapons.”… Full Article Local News
ath Trump administration models predict near doubling of daily death toll by June By www.inlander.com Published On :: Mon, 04 May 2020 14:21:00 -0700 By The New York Times The New York Times Company As President Donald Trump presses for states to reopen their economies, his administration is privately projecting a steady rise in the number of cases and deaths from the coronavirus over the next several weeks, reaching about 3,000 daily deaths June 1, according to an internal document obtained by The New York Times, nearly double from the current level of about 1,750.… Full Article Nation & World
ath Trump ignores his own public health guidelines, COVID-19 death-toll nears 70,000, and other headlines By www.inlander.com Published On :: Tue, 05 May 2020 09:24:20 -0700 ON INLANDER.COM NATION: Even as U.S. President Donald Trump urges states to reopen their economies, his own administration projects that the death toll from COVID-19 will spike to 3,000 people per day.… Full Article Local News
ath Two more residents of the Spokane Veterans Home have died, bringing death toll to five By www.inlander.com Published On :: Wed, 06 May 2020 17:54:35 -0700 Two more residents who were staying at the Spokane Veterans Home have died of complications related to COVID-19, according to the Washington State Department of Veterans Affairs. There have now been five residents of the home who have died following their diagnosis of COVID-19.… Full Article Local News
ath Modeling of time-variant threshability due to interactions between a crop in a field and atmospheric and soil conditions for prediction of daily opportunity windows for harvest operations using field-level diagnosis and prediction of weather conditions an By www.freepatentsonline.com Published On :: Tue, 19 May 2015 08:00:00 EDT A modeling framework for evaluating the impact of weather conditions on farming and harvest operations applies real-time, field-level weather data and forecasts of meteorological and climatological conditions together with user-provided and/or observed feedback of a present state of a harvest-related condition to agronomic models and to generate a plurality of harvest advisory outputs for precision agriculture. A harvest advisory model simulates and predicts the impacts of this weather information and user-provided and/or observed feedback in one or more physical, empirical, or artificial intelligence models of precision agriculture to analyze crops, plants, soils, and resulting agricultural commodities, and provides harvest advisory outputs to a diagnostic support tool for users to enhance farming and harvest decision-making, whether by providing pre-, post-, or in situ-harvest operations and crop analyzes. Full Article
ath Purification of triglyceride oil from microbial sources using short path distillation By www.freepatentsonline.com Published On :: Tue, 26 May 2015 08:00:00 EDT Disclosed is a process for reducing the amount of sterol in a sterol-containing microbial oil composition, including distilling, under short path distillation conditions, a sterol-containing microbial oil wherein said distillation produces a distillate fraction containing the sterol and a triacylglycerol-containing fraction having a reduced amount of the sterol when compared to the amount of sterol in the sterol-containing microbial oil composition that has not been subjected to short path distillation. Full Article
ath Heterocyclic compounds as imaging probes of tau pathology By www.freepatentsonline.com Published On :: Tue, 26 May 2015 08:00:00 EDT Heterocyclic compounds of formula (I) useful as imaging probes of Tau pathology in Alzheimer's disease are described. Compositions and methods of making such compounds are also described. Full Article
ath Compositions and methods for inhibition of the JAK pathway By www.freepatentsonline.com Published On :: Tue, 26 May 2015 08:00:00 EDT The invention encompasses compounds having formula I and the compositions and methods using these compounds in the treatment of conditions in which modulation of the JAK pathway or inhibition of JAK kinases are therapeutically useful. Full Article
ath Catalyst for metathesis of ethylene and 2-butene and/or double bond isomerization By www.freepatentsonline.com Published On :: Tue, 26 May 2015 08:00:00 EDT A process for the double-bond isomerization of olefins is disclosed. The process may include contacting a fluid stream comprising olefins with a fixed bed comprising an activated basic metal oxide isomerization catalyst to convert at least a portion of the olefin to its isomer. The isomerization catalysts disclosed herein may have a reduced cycle to cycle deactivation as compared to conventional catalysts, thus maintaining higher activity over the complete catalyst life cycle. Full Article
ath Z-selective ring-closing metathesis reactions By www.freepatentsonline.com Published On :: Tue, 07 Jul 2015 08:00:00 EDT The present invention relates generally to olefin metathesis. In some embodiments, the present invention provides methods for Z-selective ring-closing metathesis. Full Article
ath Method to facilitate fast context switching for partial and extended path extension to remote expanders By www.freepatentsonline.com Published On :: Tue, 26 May 2015 08:00:00 EDT A method, apparatus, and system for switching from an existing target end device to a next target end device in a multi-expander storage topology by using Fast Context Switching. The method enhances Fast Context Switching by allowing Fast Context Switching to reuse or extend part of an existing connection path to an end device directly attached to a remote expander. The method can include reusing or extending at least a partial path of an established connection between an initiator and the existing target end device for a connection between the initiator and the next target end device, whereby the existing target end device and the next target end device are locally attached to different expanders. Full Article
ath Apparatuses enabling concurrent communication between an interface die and a plurality of dice stacks, interleaved conductive paths in stacked devices, and methods for forming and operating the same By www.freepatentsonline.com Published On :: Tue, 01 Sep 2015 08:00:00 EDT Various embodiments include apparatuses, stacked devices and methods of forming dice stacks on an interface die. In one such apparatus, a dice stack includes at least a first die and a second die, and conductive paths coupling the first die and the second die to the common control die. In some embodiments, the conductive paths may be arranged to connect with circuitry on alternating dice of the stack. In other embodiments, a plurality of dice stacks may be arranged on a single interface die, and some or all of the dice may have interleaving conductive paths. Full Article
ath Apparatus for estimating travel path of a vehicle By www.freepatentsonline.com Published On :: Tue, 26 May 2015 08:00:00 EDT An apparatus for estimating a travel path of a vehicle is mounted on the vehicle; and includes: an object detection device that detects an object lying ahead of the vehicle; a stationary object detection device that determines whether a detected object is a stationary object; a device that calculates an approximate straight line indicating a path of the stationary object from the temporal positional data for the stationary object projected on two-dimensional coordinates using a vehicle position as a starting point; a device that calculates a orthogonal line which passes through a midpoint in the temporal positional data for the stationary object and goes straight with respect to the approximate straight line on the two-dimensional coordinates; and a device that calculates a vehicle turning radius from an intersection point where the orthogonal line intersects with a x axis. Full Article
ath Path information providing server, method of providing path information, and terminal By www.freepatentsonline.com Published On :: Tue, 21 Jul 2015 08:00:00 EDT Provided are an apparatus and method of providing path information based on a status of a path and/or a purpose of the use of the path. A path information providing server collects environmental information from a sensing device. The path information providing server receives a path information request including a departure and a destination from a terminal device, and provides path information generated by mapping environmental data to a searched path. Full Article