SEARCH · Engineering Papers

Results for “Differential operators”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 records

All sources NASA NTRS DOE OSTI

NASA NTRS1991

Computations involving differential operators and their actions on functions

The algorithms derived by Grossmann and Larson (1989) are further developed for rewriting expressions involving differential operators. The differential operators involved arise in the local analysis of nonlinear dynamical systems. These algorithms are extended in two different directions: the algorithms are generalized so that they apply to differential operators on groups and the data structures and algorithms are developed to compute symbolically the action of differential operators on functions. Both of these generalizations are needed for applications.

Crouch, Peter E.↗

NASA NTRS1965

On the Eigenvalues of a Singular Nonself- Adjoint Differential Operator of Second Order

Singular nonself-adjoint differential operator of second order eigenvalues

PROBLEM SOLVING↗

NASA NTRS1969

On the stability of nonlinear operator differential equations, and applications

Existence and stability problems of nonlinear operator differential equations containing linear operator with domain and range contained in real Hilbert space

Pao, C. V.↗

NASA NTRS1969

On the stability of nonlinear operator differential equations, and applications

Stability of nonlinear operator differential equations

Pao, C. V.↗

NASA NTRS1972

Eigenvalues of singular differential operators by finite difference methods. I.

Approximation of the eigenvalues of certain self-adjoint operators defined by a formal differential operator in a Hilbert space. In general, two problems are studied. The first is the problem of defining a suitable Hilbert space operator that has eigenvalues. The second problem concerns the finite difference operators to be used.

Baxley, J. V.↗

NASA NTRS1965

Differential operators and their adjoints under integral and multiple point boundary conditions

Differential operators and adjoint systems derived from Green function and Hilbert spaces

GREEN FUNCTION↗

NASA NTRS1967

On the expansion problem for nonself-adjoint ordinary differential operators of second order.

Theory of nonself-adjoint ordinary second order differential operators, discussing solution algorithms

BOUNDARY VALUE↗

NASA NTRS1966

On the eigenvalues of a singular nonself- adjoint differential operator of second order.

Characterization of eigenvalues of singular nonself-adjoint differential operator of second order

SINGULARITY /MATH/↗

NASA NTRS1965

Second order ordinary differential operators with general boundary conditions.

General boundary conditions for second-order ordinary differential operators

BOUNDARY VALUE↗

NASA NTRS1969

The existence and stability of solutions to nonlinear operator differential equation

Existance and stability of solutions to nonlinear operator differential equation

Pao, C. V.↗

NASA NTRS1969

Stability theory of nonlinear operational differential equations in Hilbert spaces

Pao, C.-V.↗

NASA NTRS1968

Differential operators and their adjoints under integral and multiple point boundary conditions.

Differential operators and adjoints defined on Hilbert space of n x 1 matrices under integral and multiple point boundary conditions

Krall, A. M.↗

NASA NTRS1969

The existence and stability of solutions of nonlinear operator differential equations

Existence and uniqueness, stability and asymptotic stability of nonlinear operator differential equation

Pao, C. V.↗

NASA NTRS1969

Stability theory of nonlinear operational differential equations in Hilbert space

Existence, uniqueness, and stability criteria for linear and nonlinear operational differential equations in Banach and Hilbert spaces

Pao, C.-V.↗

NASA NTRS1972

Eigenvalues of singular differential operators by finite difference methods. II.

Note is made of an earlier paper which defined finite difference operators for the Hilbert space L2(m), and gave the eigenvalues for these operators. The present work examines eigenvalues for higher order singular differential operators by using finite difference methods. The two self-adjoint operators investigated are defined by a particular value in the same Hilbert space, L2(m), and are strictly positive with compact inverses. A class of finite difference operators is considered, with the idea of application to the theory of Toeplitz matrices. The approximating operators consist of a good approximation plus a perturbing operator.

Baxley, J. V.↗

NASA NTRS1989

Hopf-algebraic structure of combinatorial objects and differential operators

A Hopf-algebraic structure on a vector space which has as basis a family of trees is described. Some applications of this structure to combinatorics and to differential operators are surveyed. Some possible future directions for this work are indicated.

Grossman, Robert↗

NASA NTRS1981

Existence and uniqueness of solutions to a class of nonlinear-operator-differential equations arising in automated spaceship navigation

A proof is given of the existence and uniqueness of the solution to the automatic control problem with a nonlinear state equation of the form y' = f(t,y,u) and nonlinear operator controls u = U(y) acting onto the state function y which satisfies the initial condition y(t) = x(t) for t or = 0.

Bogdan, V. M.↗

NASA NTRS1971

A method for approximating the eigenvalues of non self-adjoint ordinary differential operators

Eigenvalue approximation method for non-self-adjoint operators using Galerkin method for estimating eigenvalue perturbations of self-adjoint operators

Osborn, J. E.↗