TY  - JOUR
AU  - Tran Tuan, Hung
AU  - Do, Van Tien
TI  - Computational Aspects for Steady State Analysis of QBD Processes
JF  - PERIODICA POLYTECHNICA-ELECTRICAL ENGINEERING
J2  - PERIOD POLYTECH ELECTR ENG
VL  - 44
PY  - 2000
IS  - 2
SP  - 179
EP  - 200
PG  - 22
SN  - 0324-6000
UR  - https://m2.mtmt.hu/api/publication/2606206
ID  - 2606206
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Tran Tuan, Hung
AU  - Do, Van Tien
TI  - Generalised Invariant Subspace based Method for Steady State Analysis of QBD-M Processes
JF  - PERIODICA POLYTECHNICA-ELECTRICAL ENGINEERING
J2  - PERIOD POLYTECH ELECTR ENG
VL  - 44
PY  - 2000
IS  - 2
SP  - 159
EP  - 178
PG  - 20
SN  - 0324-6000
UR  - https://m2.mtmt.hu/api/publication/2606205
ID  - 2606205
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Telek, Miklós
AU  - Racz, S
TI  - Numerical analysis of large Markov reward models
JF  - PERFORMANCE EVALUATION
J2  - PERFORM EVALUATION
VL  - 36-37
PY  - 1999
SP  - 95
EP  - 114
PG  - 20
SN  - 0166-5316
DO  - 10.1016/S0166-5316(99)00032-2
UR  - https://m2.mtmt.hu/api/publication/2629256
ID  - 2629256
AB  - A first analysis of Markov Reward Models (MRM) resulted in a double
transform expression, whose numerical solution is based on the inverse
transformations both in time and reward variable domain. Better
numerical methods were proposed based on the time domain properties of
these models, such as the set of partial differential equations
describing the process evolution in time. This paper introduces an
effective numerical method for the analysis of MRMs based on the
transform domain description of the system, which allows the evaluation
of models with large state space (similar to 10(6) states). The
proposed method provides the moments of reward measures on the same
computational cost and memory requirement as the transient analysis of
the underlying Continuous Time Markov Chain and benefits from the
advantages of the randomization method, which avoids numerical
instabilities and provides global error bound in advance of the
computation. implementation notes and numerical examples demonstrate
the numerical properties of the proposed method are also provided. (C)
1999 Elsevier Science B.V. All rights reserved.
LA  - English
DB  - MTMT
ER  - 

TY  - CHAP
AU  - Garg, S
AU  - Puliafito, A
AU  - Telek, Miklós
AU  - Trivedi, KS
ED  - IEEE, ,
TI  - On the analysis of software rejuvenation policies
T2  - COMPASS '97: Are we making progress towards computer assurance?
PB  - IEEE Press
CY  - New York, New York
SN  - 0780339800
PY  - 1997
SP  - 88
EP  - 96
PG  - 9
UR  - https://m2.mtmt.hu/api/publication/2629710
ID  - 2629710
AB  - Software rejuvenation is a technique for software fault tolerance which involves occasionally stopping the executing software, ''cleaning'' the ''internal state'' and restarting. This cleanup is done at desirable times during execution on a preventive basis so that unplanned failures, which result in higher costs compared to planned stopping, are avoided. Since during rejuvenation, the software is typically unavailable or in a degraded mode of operation, the operation involves a cost. In this paper, we present an analytical model of a software system which serves transactions. Due to ''aging'', not only the service rate of the software decreases with time but the software itself experiences occasional crash/hang failures. We propose and compare two rejuvenation policies. The policies are evaluated for the resulting steady state availability as well the probability that a transaction is denied service. We also numerically illustrate the use of our model to compute the optimal rejuvenation interval which minimizes (maximizes) the loss probability (steady state availability).
LA  - English
DB  - MTMT
ER  -