Recently, the Legendre pseudospectral (PS) method migrated from theory to flight application onboard the International Space Station for performing a finite-horizon, zeropropellant maneuver. A small technical modification to the Legendre PS method is necessary to manage the limiting conditions at infinity for infinite-horizon optimal control problems. Motivated by these technicalities, the conc...

In this work, the convection-diffusion integro-differential equation with a weakly singular kernel is discussed. The  Legendre spectral tau method is introduced for finding the unknown function. The proposed method is based on expanding the approximate solution as the elements of a shifted Legendre polynomials. We reduce the problem to a set of algebraic equations by using operational matrices....

Legendre transformations provide a natural symmetry on the space of solutions to the WDVV equations, and more specifically, between different Frobenius manifolds. In this paper a twisted Legendre transformation is constructed between solutions which define the corresponding dual Frobenius manifolds. As an application it is shown that certain trigonometric and rational solutions of the WDVV equa...

Classic wavelet methods were developed in the Euclidean spaces for multiscale representation and analysis of regularly sampled signals (time series) and images. This paper introduces a method of representing scattered spherical data by multiscale spherical wavelets. The method extends the recent pioneering work of Narcowich and Ward [Appl. Comput. Harmon. Anal., 3 (1996), pp. 324–336] by employ...

Subtle but progressive variations in human cortical thickness have been associated with the initial phases of prevalent neurological and psychiatric conditions. But slight changes in cortical thickness at preclinical stages are typically masked by effects of the Gaussian kernel smoothing on the cortical surface shape descriptors. Here we present the first study aimed at detecting changes in hum...

The Euler equations subject to uncertainty in the input parameters are investigated via the stochastic Galerkin approach. We present a new fully intrusive method based on a variable transformation of the continuous equations. Roe variables are employed to get quadratic dependence in the flux function and a well-defined Roe average matrix that can be determined without matrix inversion. In previ...

S U M M A R Y We present a spherical wavelet-based multiscale approach for estimating a spatial velocity field on the sphere from a set of irregularly spaced geodetic displacement observations. Because the adopted spherical wavelets are analytically differentiable, spatial gradient tensor quantities such as dilatation rate, strain rate and rotation rate can be directly computed using the same c...

In this correspondence we determine the linear complexity of all Legendre sequences and the (monic) feedback polynomial of the shortest linear feedback shift register that generates such a Legendre sequence. The result of this correspondence shows that Legendre sequences are quite good from the linear complexity viewpoint.

A dynamic adaptive numerical method for solving partial differential equations on the sphere is developed. The method is based on second generation spherical wavelets on almost uniform nested spherical triangular grids, and is an extension of the adaptive wavelet collocation method to curved manifolds. Wavelet decomposition is used for grid adaption and interpolation. An OðN Þ hierarchical fini...

In this work, a new adaptive multi-level approximation of surface divergence and scalar-valued surface curl operator on a recursively refined spherical geodesic grid is presented. A hierarchical finite volume scheme based on the wavelet multi-level decomposition is used to approximate the surface divergence and scalar-valued surface curl operator. The multi-level structure provides a simple way...