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Displaying 601 –
620 of
1956
It is well-known that the environments of most natural populations change with time and that such changes induce variation in the growth characteristics of population which is often modelled by delay differential equations, usually with
time-varying delay. The purpose of this article is to derive a numerical solution
of the delay differential system with continuously distributed delays based on
a composition of -step methods () and quadrature formulas. Some numerical results are presented compared...
In this paper a nonmonotone limited memory BFGS (NLBFGS) method is applied for approximately solving optimal control problems (OCPs) governed by one-dimensional parabolic partial differential equations. A discretized optimal control problem is obtained by using piecewise linear finite element and well-known backward Euler methods. Afterwards, regarding the implicit function theorem, the optimal control problem is transformed into an unconstrained nonlinear optimization problem (UNOP). Finally the...
This study is mainly dedicated to the development and analysis of non-overlapping domain decomposition methods for solving continuous-pressure finite element formulations of the Stokes problem. These methods have the following special features. By keeping the equations and unknowns unchanged at the cross points, that is, points shared by more than two subdomains, one can interpret them as iterative solvers of the actual discrete problem directly issued from the finite element scheme. In this way,...
This study is mainly dedicated to the development and analysis of
non-overlapping domain decomposition methods for solving continuous-pressure
finite element formulations of the Stokes problem. These methods have the
following special features. By keeping the equations and unknowns unchanged at
the cross points, that is, points shared by more than two subdomains, one can
interpret them as iterative solvers of the actual discrete problem directly
issued from the finite element scheme. In this way,...
This paper is concerned with the stabilisation of linear time-delay systems by tuning a finite number of parameters. Such problems typically arise in the design of fixed-order controllers. As time-delay systems exhibit an infinite amount of characteristic roots, a full assignment of the spectrum is impossible. However, if the system is stabilisable for the given parameter set, stability can in principle always be achieved through minimising the real part of the rightmost characteristic root, or...
This paper is concerned with the stabilisation of linear time-delay systems
by tuning a finite number of parameters. Such problems typically arise in the
design of fixed-order controllers. As time-delay systems exhibit an infinite amount of
characteristic roots, a full assignment of the spectrum is impossible.
However, if the system is stabilisable for the given parameter set, stability can
in principle always be achieved through minimising the real part of the rightmost
characteristic...
An algorithm for univariate optimization using a linear lower bounding function is extended to a nonsmooth case by using the generalized gradient instead of the derivative. A convergence theorem is proved under the condition of semismoothness. This approach gives a globally superlinear convergence of algorithm, which is a generalized Newton-type method.
Specialized literature concerning studies on Orbital Dynamics usually mentions the Gauss-Jackson or sum squared (∑2) method for the numerical integration of second order differential equations. However, as far as we know, no detailed description of this code is available and there is some confusion about the order of the method and its relation with the Störmer method. In this paper we present a simple way of deriving this algorithm and its corresponding analog for first order equations from the...
First–order accurate monotone conservative schemes have good convergence and stability properties, and thus play a very important role in designing modern high resolution shock-capturing schemes. Do the monotone difference approximations always give a good numerical solution in sense of monotonicity preservation or suppression of oscillations? This note will investigate this problem from a numerical point of view and show that a -point monotone scheme may give an oscillatory solution even though...
First–order accurate monotone conservative schemes have good
convergence and stability properties, and thus play a very
important role in designing modern high resolution shock-capturing
schemes.
Do the monotone difference approximations always
give a good numerical solution in sense of monotonicity preservation
or suppression of oscillations? This note will investigate this problem
from a numerical point of view and show that
a (2K+1)-point monotone scheme may give an oscillatory solution
even...
The paper concerns a two-level hierarchical game, where the players on each level behave noncooperatively. In this way one can model eg an oligopolistic market with several large and several small firms. We derive two types of necessary conditions for a solution of this game and discuss briefly the possibilities of its computation.
The proof of the Friedrichs' inequality on the class of finite dimensional spaces used in the finite element method is given. In particular, the approximate spaces generated by simplicial isoparametric elements are considered.
Currently displaying 601 –
620 of
1956