due to the changes which may occur in their parameters, systems are usually demonstrated by some subsystems for different conditions. this paper employs modified petri nets (mpn) to model theses subsystems and makes it simple to analyze them. in this method, first, the continuous transfer function is converted to a discrete transfer function and then, by mpn, system is modeled and analyzed. all...

in this paper the problem of minimizing the total transmitting power subject to a fixedtotal bit rate in ofdm systems is considered. upper bounds on transmitting power and bit rate ofeach subcarrier can also be taken into account. in practice, the number of bits of each subcarriershould be integer and nonnegative. in this paper an analytical optimal solution is derived for thecase of assuming t...

r. ewing, o. liev, r. lazarov and a. naumovich in [1] proposed a finite volume discretization for one dimensional biot poroelasticity system in multilayer domains. their discretization and exact solution are invalid. we derive valid discretization and exact solution. finally, our numerical solution is compared with known exact solution in discrete l2 norm.

Hidden Markov Model is a popular statisical method that is used in continious and discrete speech recognition. The probability density function of observation vectors in each state is estimated with discrete density or continious density modeling. The performance (in correct word recognition rate) of continious density is higher than discrete density HMM, but its computation complexity is very ...

This paper analyzes a discrete-time $Geo/Geo/c$ queueing system with multiple working vacations and reneging in which customers arrive according to a geometric process. As soon as the system gets empty, the servers go to a working vacations all together. The service times during regular busy period, working vacation period and vacation times are assumed to be geometrically distributed. Customer...

In this study, a mixed $delta$-shock model with discrete-time is defined by combining $delta$-shock and extreme shock models. In this model, a system with multiple states fails in two ways: first, when k interarrival times between two consecutive shocks with magnitude larger than the critical threshold $gamma$ are in $[delta_1, delta _2], delta_1 < delta _2$; and second, when the interarrival t...

The optimal reactive power dispatch (ORPD) is a very important problem aspect of power system planning and is a highly nonlinear, non-convex optimization problem because consist of both continuous and discrete control variables. Since the power system has inherent uncertainty, hereby, this paper presents both of the deterministic and stochastic models for ORPD problem in multi objective and sin...

since the analysis of complex services systems by using mathematical modeling techniques, with considering the random patterns prevailing in them, is so difficult or probably impossible, improvement guidelines are often followed based on the experts&apos; experiences using qualitative methods. in the present paper, by employing a discrete event computer simulation methodology, criminal trial sy...

In previous studies we first concentrated on utilizing crisp simulationto produce discrete event fuzzy systems simulations. Then we extendedthis research to the simulation of continuous fuzzy systems models. In this paperwe continue our study of continuous fuzzy systems using crisp continuoussimulation. Consider a crisp continuous system whose evolution depends ondifferential equations. Such a ...