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Articles 25951 - 25980 of 27386

Full-Text Articles in Physical Sciences and Mathematics

On The Structure Of Divergence-Free Tensors, Ian M. Anderson Jan 1978

On The Structure Of Divergence-Free Tensors, Ian M. Anderson

Mathematics and Statistics Faculty Publications

Contravariant rank two tensors which are divergence‐free on one index and which are constructed from the metric tensor, an auxiliary collection of arbitrary tensor fields, and the first and second partial derivatives of these quantities are classified. The results generalize existing mathematical arguments in support of the Einstein field equations

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Algorithms For The Solution Of Systems Of Coupled Second-Order Ordinary Differential Equations, Brendan O'Shea Jan 1978

Algorithms For The Solution Of Systems Of Coupled Second-Order Ordinary Differential Equations, Brendan O'Shea

Articles

Several step-by-step methods for the computer solution systems of coupled second-order ordinary differential equations, are examined from the point of view of efficiency “time-wise” and “storage-wise”. Particular reference is made to a system arising in the close-coupling approximation of the Schroedinger equation. The stability of the solution is also considered.

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Endomorphism Rings Of Torsion-Free Modules Over A Complete Discret Valuation Ring., Brendan Goldsmith Jan 1978

Endomorphism Rings Of Torsion-Free Modules Over A Complete Discret Valuation Ring., Brendan Goldsmith

Articles

No abstract available.

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A Direct Computational Method For Estimating The Parameters Of A Nonlinear Model, Jerome Eisenfeld, Stephen W. Cheng Jan 1978

A Direct Computational Method For Estimating The Parameters Of A Nonlinear Model, Jerome Eisenfeld, Stephen W. Cheng

Mathematics Technical Papers

We consider the system identification problem which deals with determining information about the unknown constant matrices A, B, and C or the linear dynamical system: [see pdf for notation], where u(t) and y(t) are given discretely on the interval [0,T]. This leads to a nonlinear estimation problem, or a so-called deconvolution problem, which deals with estimating the number of components [see pdf for notation], the decay rates [see pdf for notation], and the corresponding amplitudes [see pdf for notation] in the model: [see pdf for notation] from the given discrete data [see pdf for notation]. Deconvolution problems are important in …

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The Sl(5r) Lie Invariance Transformation Group For The 3-Dimensional Classical Kepler Problem : A Preparation, And Induced Group Structure Algorithm Derivation, Mark Paul Merner Jan 1978

The Sl(5r) Lie Invariance Transformation Group For The 3-Dimensional Classical Kepler Problem : A Preparation, And Induced Group Structure Algorithm Derivation, Mark Paul Merner

University of the Pacific Theses and Dissertations

Recently,1 an algorithm has been derived for the explicit determination of an induced SL (n+2,R) Lie invariance transformation group for a completely integrable 2n - dimensional dynamical system defined on IR2n from that known for a free particle system with n degree of freedom. 2 In particular, the universal transitive Lie invariance transformation group for both the isotropic harmonic oscillator3 and the anharmonic oscillator4 (quartic potential) has been obtained by this algorithm. Further,5 it has been shown in theory and by example that a complete set of functionally independent constants of motion corresponds to an …

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System Identification Of Models Exhibiting Exponential, Harmonic And Resonant Modes, B. Soni, Jerome Eisenfeld Jan 1978

System Identification Of Models Exhibiting Exponential, Harmonic And Resonant Modes, B. Soni, Jerome Eisenfeld

Mathematics Technical Papers

A classical problem arising in compartmental analysis is the so called identification problem or the inverse problem. One is presented with the linear time invariant compartmental model [see pdf for notation] [see pdf for notation] Where A is a square matrix and the dimensions of B and C are consistent with that of A. The problem is to estimate a certain subset of the matrix elements [see pdf for notation], [see pdf for notation] and [see pdf for notation] from discrete observations of the input vector u(t) and the output vector y(t). When instantaneous mixing is assumed the analogous equations …

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A Topological Approach To A Problem Of Nunke, Brendan Goldsmith Jan 1978

A Topological Approach To A Problem Of Nunke, Brendan Goldsmith

Articles

No abstract available

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Essentially-Rigid Families Of Abelian P-Groups, Brendan Goldsmith Jan 1978

Essentially-Rigid Families Of Abelian P-Groups, Brendan Goldsmith

Articles

No abstract available

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Inferences On The Shape Parameter Of The Gamma Distribution And Cramer-Rao Lower Bounds From Censored Data, James Wyckoff Jan 1978

Inferences On The Shape Parameter Of The Gamma Distribution And Cramer-Rao Lower Bounds From Censored Data, James Wyckoff

Doctoral Dissertations

"This dissertation is presented in publication form and consists of two articles. The first article considers inferential procedures on the shape parameter of a gamma distribution from censored sampling. Moments for the statistic T = log(x̅r/x͠r) are found and used to derive a two-moment chi-square approximation for T. This approximation is then used for testing, estimating, and setting confidence bounds on the shape parameter of a gamma distribution. The second article concerns the Cramér-Rao lower bounds for the variances of estimators, where the estimators are based on censored data. Convenient techniques are derived to evaluate the …

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Competitive-Cooperative Processes And Stability Of Diffusion Systems, V. Lakshmikantham, G. S. Ladde Jan 1978

Competitive-Cooperative Processes And Stability Of Diffusion Systems, V. Lakshmikantham, G. S. Ladde

Mathematics Technical Papers

Very recently, the stability analysis of deterministic [12], random [12,13] competitive-cooperative process has been made in a systematic and unified way. It is well recognized that the probabilistic models in biological [7,9,19,20,30], physical [7,20,21,30], and social [31] sciences are more realistic than the deterministic models. In this paper, we extend the stability analysis of random competitive-cooperative processes [11] to the stability analysis of competitive processes of the diffusion type. The stability results presented includes the stability analysis of multispecies community models [16,17] under white-noise excitations. All our results are in the frame-work of the earlier results [11-13, 16-18]. The paper …

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Complementary Extremum Principles, J. Swetits, C. Rogers Jan 1978

Complementary Extremum Principles, J. Swetits, C. Rogers

Mathematics & Statistics Faculty Publications

Important complementary extremum principles are generated without recourse to general variational theory. The results are illustrated by an application to a class of boundary value problems in Magnetohydrodynamics.

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Monotone Methods For Nonlinear Boundary Value Problems In Banach Spaces, Stephen R. Bernfeld, V. Lakshmikantham Dec 1977

Monotone Methods For Nonlinear Boundary Value Problems In Banach Spaces, Stephen R. Bernfeld, V. Lakshmikantham

Mathematics Technical Papers

Monotone methods have been used to generate multiple solutions of nonlinear boundary value problems for both ordinary and partial differential equations. Keller [10] and Sattinger [13], extending the chord method, considered nonlinear partial differential equations containing no gradient term. The inclusion of the gradient term was first introduced by Chandra and Davis [6] who considered the ordinary boundary value problem (1.1) [see pdf for notation] (1.2) [see pdf for notation] Here [see pdf for notation]. They assumed that f depends linearly on [see pdf for notation]; and this restriction on [see pdf for notation]' was eliminated by Bernfeld and Chandra …

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Remarks On Numerical Computations Using The Alternative Method, R. Kannan, Jerome Eisenfeld, Stephen R. Bernfeld Dec 1977

Remarks On Numerical Computations Using The Alternative Method, R. Kannan, Jerome Eisenfeld, Stephen R. Bernfeld

Mathematics Technical Papers

Recently Cesari and Bowman [1] have demonstrated the applicability of the alternative method to obtain approximate solutions of nonlinear equations. They provided numerical approximations of solutions of two point nonlinear boundary value problems. Our purpose here is to point out how these approximations may be improved upon without much additional effort. For illustrative purposes we discuss one of their examples.

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Scs 42: Generalized Continuous Lattices, Gerhard Gierz, Jimmie D. Lawson Nov 1977

Scs 42: Generalized Continuous Lattices, Gerhard Gierz, Jimmie D. Lawson

Seminar on Continuity in Semilattices

No abstract provided.

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Fixed Point Theorem For Non-Expansive Mappings On Banach Spaces With Unifformly Normal Structure, B. B. Williams, A. A. Gillespie Nov 1977

Fixed Point Theorem For Non-Expansive Mappings On Banach Spaces With Unifformly Normal Structure, B. B. Williams, A. A. Gillespie

Mathematics Technical Papers

In [1] Kirk proved that if D is a bounded, closed, and convex subset of a reflexive Banach space that has normal structure, then every non-expansive mapping of D into D has a fixed point. This was also proved for a uniformly convex space by Browder [2]. In this paper we replace uniformly convex, or reflexive and normal structure, by uniformly normal structure to obtain this result. Let S be a bounded subset of the Banach space X and [see pdf for notation] (1) [see pdf for notation] (2) [see pdf for notation] (3) [see pdf for notation] A space …

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Pitman-Closeness Efficiency Of Estimators Of Reliability With Application To The Exponent/Al Failure Model, Jerome P. Keating, Danny D. Dyer Oct 1977

Pitman-Closeness Efficiency Of Estimators Of Reliability With Application To The Exponent/Al Failure Model, Jerome P. Keating, Danny D. Dyer

Mathematics Technical Papers

When there are available several point estimators of component or system reliability, it would be of interest to compare such estimators through some "closeness to the true value of reliability" criteria. Along these lines, the concept of Pitman-closeness efficiency is introduced. Essentially, when comparing two estimators of reliability for a given situation, Pitman-closeness efficiency gives the odds in favor of one of the estimators being closer to the true value of reliability than is the other. Theory is developed which provides a straightforward way to evaluate this measure of efficiency under fairly general conditions on the estimators. Based on this …

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Scs 41: An Exercise On The Spectrum Of Function Spaces, Karl Heinrich Hofmann, Dana S. Scott Sep 1977

Scs 41: An Exercise On The Spectrum Of Function Spaces, Karl Heinrich Hofmann, Dana S. Scott

Seminar on Continuity in Semilattices

No abstract provided.

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Independence Theories And Generalized Zero-One Laws, Lawrence Stout Aug 1977

Independence Theories And Generalized Zero-One Laws, Lawrence Stout

Lawrence N. Stout

In this paper an abstract characterization of the properties of independent events is given with examples from topology, probability, and Baire structures. Using this notion of independence, proofs of the Hewitt-Savage and Kolmogorov zero-one laws are given which include the probabilistic case and the topological cases considered by Oxtoby, Christensen, and K. P. S. and M. Bhaskara Rao.

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Comparison Of Point Estimators Of Normal Percentiles, Danny D. Dyer, Onas L. Hensley, Jerome P. Keating Aug 1977

Comparison Of Point Estimators Of Normal Percentiles, Danny D. Dyer, Onas L. Hensley, Jerome P. Keating

Mathematics Technical Papers

There are available several point estimators of the percentiles of a normal distribution with both mean and variance unknown. Consequently, it would seam appropriate to make a comparison among the estimators through sums "closeness to the true value" criteria. Along these lines, the concept of Pitman-closeness efficiency is introduced. Essentially, when comparing two estimators, the Pitman-closeness efficiency gives "odds" in favor of one of the estimators being closer to the true value than is the other in a given situation. Through the use of Pitman-closeness efficiency, this paper compares (a) the maximum likelihood estimator, (b) the minimum variance unbissed estimator, …

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Partitions Of The Vertex Set Or Edge Set Of A Graph, H. Joseph Straight Aug 1977

Partitions Of The Vertex Set Or Edge Set Of A Graph, H. Joseph Straight

Dissertations

No abstract provided.

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Scs 40: A New Approach To Some Results Of Lawson, Gierz And Hofmann, Michael Mislove Jul 1977

Scs 40: A New Approach To Some Results Of Lawson, Gierz And Hofmann, Michael Mislove

Seminar on Continuity in Semilattices

No abstract provided.

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A Study Of Admissibility Through Exterior Boundary Value Problem., C. Srinivasan Dr. Jul 1977

A Study Of Admissibility Through Exterior Boundary Value Problem., C. Srinivasan Dr.

Doctoral Theses

The study of admissible decision procedures began in late forties when Wald introduced the concept to characterize the minimal complete class of decision procedures. Starting with the pioneering work of Abraham Wald, there has been considerable contribution to this area over the last three decades. However, most of the articles in this field dealt with specific decision procedures arid studied their admissibility. It was Stein [11 who first characterized, admissible decision procedures. Farrell ([2], (3]) generalized the result of Stein. In spite of the works of Stein and Farrell the problem of deciding whether a given decision procedure is admissible …

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Numerical Methods For Multipoint Boundary Value Problems, Mahoud Abdul-Ghani Sarhan Jul 1977

Numerical Methods For Multipoint Boundary Value Problems, Mahoud Abdul-Ghani Sarhan

Mathematics & Statistics ETDs

Existence and uniqueness theory for ordinary differential systems subject to linear constraints is presented in some detail. Finite difference schemes, shooting methods, orthonormalization procedures and projection methods are studied. Orthonormalization procedures are shown to be ineffective for the general linear problem. Projection methods for linear differential systems with fairly general multipoint boundary conditions are thoroughly developed. Two particular examples of such methods are given: Galerkin and collocation. The various numerical methods considered are evaluated and compared. Several examples are discussed and numerical results are displayed .

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Scs 38: Treillis Continus Et Treillis Complètement Distributifs, Morike Kamara Jul 1977

Scs 38: Treillis Continus Et Treillis Complètement Distributifs, Morike Kamara

Seminar on Continuity in Semilattices

No abstract provided.

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Scs 39: Quotients Of Cubes, Albert R. Stralka Jul 1977

Scs 39: Quotients Of Cubes, Albert R. Stralka

Seminar on Continuity in Semilattices

No abstract provided.

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Existence And Uniqueness Of Sobolev Type Integrodifferential Equations, M. E. Lord Jul 1977

Existence And Uniqueness Of Sobolev Type Integrodifferential Equations, M. E. Lord

Mathematics Technical Papers

An imbedding method for nonlinear Fredholm integral equations gives rise to a Sobolev type integrodifferential equation. For such equations, sufficient conditions are given to guarantee local existence and uniqueness of solutions. A Picard type theorem utilizing a Lipschitz condition is obtained.

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Fragments Of 1st-Order Logic, I: Universal Horn Logic, George F. Mcnulty Jun 1977

Fragments Of 1st-Order Logic, I: Universal Horn Logic, George F. Mcnulty

Faculty Publications

No abstract provided.

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The Method Of Nonlinear Variation Of Constants For Difference Equations, M. E. Lord Jun 1977

The Method Of Nonlinear Variation Of Constants For Difference Equations, M. E. Lord

Mathematics Technical Papers

A method of nonlinear variation of constants for discrete difference equations is developed, which generalizes a well-known linear variation of constants formula. The method is shown to be useful in studying asymptotic behavior of perturbed nonlinear difference equations.

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Sobolev Type Differential Equations, M. E. Lord, V. Lakshmikantham Jun 1977

Sobolev Type Differential Equations, M. E. Lord, V. Lakshmikantham

Mathematics Technical Papers

An imbedding method for solving linear Fredholm integral equations was introduced by Sobolev [3] which involves the solution of the following differential equation with initial value for the resolvent kernel [see pdf for notation]. The differential equation in (1.1) is unusual in that the solution K(t,y,x) is evaluated at different combinations of the independent variables (t,y,x) . We will refer to any differential equation with this property as a Sobolev type differential equation. We introduce a Sobolev type differential equation which generalizes (1.1) and consider conditions for existence and uniqueness. A Picard type theorem is obtained, which by way of …

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Scs 37: Comments On The Spectral Theory Of Continuous Lattices, Oswald Wyler May 1977

Scs 37: Comments On The Spectral Theory Of Continuous Lattices, Oswald Wyler

Seminar on Continuity in Semilattices

No abstract provided.

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