We design here a primary platform for computing the basic homological information of Commutative Di erential Graded Algebras (brie y, CDGAs), endowed with linear di erential. All the algorithms have been implemented in the framework settled by Mathematica, so that we can take advantage of the use of symbolic computation and many other powerful tools this system provides. Working in the context ...

This work deals with the design of the low{level stages of any di erential{ based optical ow algorithm. The problem is the accurate estimaton of the spatio{temporal derivatives of the moving image, to be used in the solution of the gradient constraint equation. We claim that the \traditional" techniques for the partial derivatives estimation can be improved by i) exploiting all the information ...

In a series of papers, starting with [Fully nonlinear stochastic partial di¤erential equations. C. R. Acad. Sci. Paris Sér. I Math. 326 (1998), no. 9] Lions and Souganidis proposed a (pathwise) theory for fully non-linear stochastic partial di¤erential equations. We present here a (partial) extension towards certain spatial dependence in the noise term. The main novelty is the use of rough path...

We suggest two algorithms that allow e cient timing recovery for MSK based on the computation of the Fourier spectrum of the absolute value of the di erential phases. One is suited for parallel frequency estimation while the second is less complex but requires previous frequency correction. The algorithms are investigated using both analysis and simulation. The two algorithms approximately lead...

We study some classes of generalized convex functions, using a generalized di¤erential approach. By this we mean a set-valued mapping which stands either for a derivative, a subdi¤erential or a pseudodi¤erential in the sense of Jeyakumar and Luc. We establish some links between the corresponding classes of pseudoconvex, quasiconvex and another class of generalized convex functions we introduced...

We present a case study of a formal veri cation of a numerical program that computes the discretization of a simple partial di erential equation. Bounding the rounding error was tricky as the usual idea, that is to bound the absolute value of the error at each step, fails. Our idea is to nd out a precise analytical expression that cancels with itself at the next step, and to formally prove the ...

We establish comparison and existence theorems of viscosity solutions of the initial-boundary value problem for some singular degenerate parabolic partial di/erential equations with nonlinear oblique derivative boundary conditions. The theorems cover the capillary problem for the mean curvature 1ow equation and apply to more general Neumann-type boundary problems for parabolic equations in the ...

The di erential equation dX dt = [X; k(X)] where k is a Toeplitz annihilator has been suggested as a means to solve the inverse Toeplitz eigenvalue problem. Starting with the diagonal matrix whose entries are the same as the given eigenvalues, the solution ow has been observed numerically to always converge a symmetric Toeplitz matrix as t ! 1. This paper is an attempt to understand the dynamic...

An important question about a ne skeletons is the existence of di erential equations that are related to the A ne Distance and the Area Distance (hence to a ne skeletons) in the same way the Eikonal equation is related to the Euclidean Distance (and the medial axis). We show a surprisingly simple nonlinear second order PDE of Monge-Ampère type that relates to the a ne skeletons (and extends the...

In this paper conditional hidden Markov model (HMM) lters and conditional Kalman lters (KF) are coupled together to improve demodulation of di erential encoded signals in noisy fading channels. We present an indicator matrix representation for di erential encoded signals and the optimal HMM lter for demodulation. The lter requires O(N) calculations per time iteration, where N is the number of m...