ESTIMATING DISCRETE-TIME PERIODIC SOFTWARE REJUVENATION SCHEDULES UNDER COST EFFECTIVENESS CRITERION

2006 ◽  
Vol 13 (06) ◽  
pp. 565-579
Author(s):  
KAZUKI IWAMOTO ◽  
TADASHI DOHI ◽  
NAOTO KAIO
Keyword(s):  
Asymptotic Behavior ◽  
Cost Effectiveness ◽  
Discrete Time ◽  
Parametric Method ◽  
Regenerative Process ◽  
Numerical Examples ◽  
Software Aging ◽  
Software Rejuvenation ◽  
Markov Regenerative Process ◽  
Time Periodic

Software rejuvenation is a preventive and proactive solution that is particularly useful for counteracting the phenomenon of software aging. In this article, we consider the similar periodic software rejuvenation model to Garg et al.13 under the different operation circumstance. That is, we model the stochastic behavior of telecommunication billing applications by using a discrete-time Markov regenerative process, and determine the optimal periodic software rejuvenation schedule maximizing the so-called cost effectiveness, in discrete-time setting. Also, we provide a statistically non-parametric method to estimate the optimal software rejuvenation schedule, based on the discrete total time on test concept. Numerical examples are devoted to illustrate the determination/estimation of the optimal software rejuvenation schedule and to examine the asymptotic behavior of the estimator developed here.

scholarly journals Extending the CGLS method for finding the least squares solutions of general discrete-time periodic matrix equations

Filomat ◽  
2016 ◽  
Vol 30 (9) ◽  
pp. 2503-2520 ◽  
Author(s):  
Masoud Hajarian
Keyword(s):  
Finite Number ◽  
Least Squares ◽  
Control Systems ◽  
Discrete Time ◽  
Conjugate Gradient ◽  
Matrix Form ◽  
Matrix Equations ◽  
Numerical Examples ◽  
Periodic Matrix ◽  
Time Periodic

The periodic matrix equations are strongly related to analysis of periodic control systems for various engineering and mechanical problems. In this work, a matrix form of the conjugate gradient for least squares (MCGLS) method is constructed for obtaining the least squares solutions of the general discrete-time periodic matrix equations ?t,j=1 (Ai,jXi,jBi,j + Ci,jXi+1,jDi,j)=Mi, i=1,2,.... It is shown that the MCGLS method converges smoothly in a finite number of steps in the absence of round-off errors. Finally two numerical examples show that the MCGLS method is efficient.

scholarly journals Optimization of Two-Granularity Software Rejuvenation Policy Based on the Markov Regenerative Process

2016 ◽  
Vol 65 (4) ◽  
pp. 1630-1646 ◽  
Author(s):  
Gaorong Ning ◽  
Jing Zhao ◽  
Yunlong Lou ◽  
Javier Alonso ◽  
Rivalino Matias ◽  
...  
Keyword(s):  
Regenerative Process ◽  
Software Rejuvenation ◽  
Markov Regenerative Process

scholarly journals GRADIENT BASED ITERATIVE ALGORITHM TO SOLVE GENERAL COUPLED DISCRETE-TIME PERIODIC MATRIX EQUATIONS OVER GENERALIZED REFLEXIVE MATRICES

2016 ◽  
Vol 21 (4) ◽  
pp. 533-549 ◽  
Author(s):  
Masoud Hajarian
Keyword(s):  
Iterative Algorithm ◽  
Discrete Time ◽  
State Feedback ◽  
Descriptor Systems ◽  
Matrix Equations ◽  
Numerical Examples ◽  
Periodic Matrix ◽  
Periodic State ◽  
Gradient Based ◽  
Time Periodic

The discrete-time periodic matrix equations are encountered in periodic state feedback problems and model reduction of periodic descriptor systems. The aim of this paper is to compute the generalized reflexive solutions of the general coupled discrete-time periodic matrix equations. We introduce a gradient-based iterative (GI) algorithm for finding the generalized reflexive solutions of the general coupled discretetime periodic matrix equations. It is shown that the introduced GI algorithm always converges to the generalized reflexive solutions for any initial generalized reflexive matrices. Finally, two numerical examples are investigated to confirm the efficiency of GI algorithm.

Positive stable realizations of discrete-time linear systems

2012 ◽  
Vol 60 (3) ◽  
pp. 605-616
Author(s):  
T. Kaczorek
Keyword(s):  
Transfer Function ◽  
Discrete Time ◽  
Sufficient Conditions ◽  
Asymptotically Stable ◽  
Numerical Examples ◽  
Discrete Time Systems ◽  
Necessary And Sufficient ◽  
Time Systems ◽  
Time Linear

Abstract The problem of existence and determination of the set of positive asymptotically stable realizations of a proper transfer function of linear discrete-time systems is formulated and solved. Necessary and sufficient conditions for existence of the set of the realizations are established. A procedure for computation of the set of realizations are proposed and illustrated by numerical examples.

Sign in / Sign up

Export Citation Format

Share Document