Numerical methods have been developed to solve optimal feedback control problems for nonlinear continuous-time dynamical systems, perturbed by Poisson as well as Gaussian random white noise. Predictor-corrector method...
详细信息
Numerical methods have been developed to solve optimal feedback control problems for nonlinear continuous-time dynamical systems, perturbed by Poisson as well as Gaussian random white noise. Predictor-corrector methods have been modified for the nonstandard functional partial differential equation of stochastic dynamic programming to treat nonlinearities attributable to quadratic costs and non-smoothness attributable to control switching. This numerical formulation is highly suitable for vectorization and parallelization techniques. Advanced computing techniques and hardware help alleviate Bellman's curse of dimensionality in dynamic programming computations.
A fourth-order predictor-corrector method is developed for obtaining the numerical solution of a class of singular boundary value problems in which the highest derivative is further multiplied by a parameter which can...
详细信息
A fourth-order predictor-corrector method is developed for obtaining the numerical solution of a class of singular boundary value problems in which the highest derivative is further multiplied by a parameter which can lake arbitrarily small values. First, the method is tested on a prototype linear differential equation. It is then used to compute the two-dimensional stagnation point flow of a viscoelastic fluid. Finally, the flow over a stretching sheet is computed for which an exact solution exists. The comparison of the results shows that the method gives highly accurate results for a moderately sized integration step.
The two-dimensional wave front emitted by a circular impulsive source in a transversely isotropic elastic solid is analyzed with respect to its geometric shape. It is found that the concept of slowness curve, previous...
The two-dimensional wave front emitted by a circular impulsive source in a transversely isotropic elastic solid is analyzed with respect to its geometric shape. It is found that the concept of slowness curve, previously used to explain features of a point source wave front, can be generalized so as to include a circular source. This generalized slowness curve is time-dependent.
A model of magnitude relative error in floating point multiplication is developed and is analyzed stochastically for various choices of computer design parameters. These parameters include the base, the type of roundi...
详细信息
A model of magnitude relative error in floating point multiplication is developed and is analyzed stochastically for various choices of computer design parameters. These parameters include the base, the type of rounding rule, the number of guard digits, and whether the post-arithmetic normalization shift (if needed) is done before or after rounding. Under the assumption of logarithmic distribution for the fraction (mantissa), the major stochastic conclusions are: (1) The average magnitude relative error in multiplication increases as the base increases. (2) The average error is minimized by selecting the machine base to be binary with a hidden bit, and is larger for base 16. Other models of relative error are developed and analyzed.
It is shown that if the natural order on a total extension (P) over bar of an effect algebra P coincides with the order on P, then (P) over bar is unique. The structure of (P) over bar is called a QI-algebra. It is sh...
详细信息
It is shown that if the natural order on a total extension (P) over bar of an effect algebra P coincides with the order on P, then (P) over bar is unique. The structure of (P) over bar is called a QI-algebra. It is shown that a QI-algebra is less general than a QMV-algebra, but that a QI-algebra is equivalent to a quasi-linear QMV-algebra. Some examples are given and the properties of these structures are studied.
New growth estimates are established for classes of uniformly bounded solutions to initial-value problems associated with abstract second-order integrodifferential equations; the abstract problem models the behaviour ...
New growth estimates are established for classes of uniformly bounded solutions to initial-value problems associated with abstract second-order integrodifferential equations; the abstract problem models the behaviour of a linear isothermal viscoelastic body subject to homogeneous Dirichlet boundary data. No hypotheses, other than the usual symmetry assumption, are made concerning the initial value of the relaxation tensor; our results apply to the case where the initial energy ℰ(0)>− Σ, with Σ a computable non-negative real constant, so that, in particular, the estimates derived apply to viscoelastic bodies with non-negative initial energy.
This is the 23rd Self-Assessment Procedure.1 The purpose of this procedure is to let its readers test their knowledge of some of the more important features of significant programming languages. The features of impera...
详细信息
This is the 23rd Self-Assessment Procedure.1 The purpose of this procedure is to let its readers test their knowledge of some of the more important features of significant programming languages. The features of imperative languages like Fortran, Algol 60, PL/I, Pascal, Modula-2, C, and Ada considered are data types, data structures, control structures, program units, scope of names, and parameter passing. Some of the corresponding features of functional languages like Lisp, logic programming languages like Prolog, and ohject-oriented programming languages like C++ and Smalltalk, are reviewed. Finally brief consideration is given to syntax and semantics, chiefly by reference to the Backus-Naur form, BNF. The features of programming languages affect all aspects of programming, including the ease of writing and maintaining programs, the reliahility of software, and the efficiency and portability of programs. Knowledge of programming language concepts and constructs is of importance to software developers, programmers, and designers of programming languages and compilers. The topic of this procedure should be of interest to any computerscience student or practitioner who wishes to test his or her knowledge and learn more about one of the most important and broad areas in the computer field. The language used most often in the questions is Pascal, with Ada, Lisp, and Prolog also featured prominently. A glossary is included which defines some of the terms used in the procedure. The questions are either multiple-choice or short answer. Some of the multiple-choice questions allow for more than one correct answer.
In this work, we propose a new approach, namely ansatz method, for solving fractional differential equations based on a fractional complex transform and apply it to the nonlinear partial space-time fractional modified...
详细信息
In this work, we propose a new approach, namely ansatz method, for solving fractional differential equations based on a fractional complex transform and apply it to the nonlinear partial space-time fractional modified Benjamin-Bona- Mahoney （mBBM） equation, the time fractional mKdV equation and the nonlinear fractional Zoomeron equation which gives rise to some new exact solutions. The physical parameters in the soliton solutions： amplitude, inverse width, free parameters and velocity are obtained as functions of the dependent model coefficients. This method is suitable and more powerful for solving other kinds of nonlinear fractional PDEs arising in mathematical physics. Since the fractional deriva- tives are described in the modified Riemann-Liouville sense.
Quantum Key Distribution (QKD) is currently being discussed as a technology to safeguard communication in a future where quantum computers compromise traditional public-key cryptosystems. In this paper, we conduct a c...
详细信息
暂无评论