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...

this paper proposes an efficient algorithm based on memetic algorithm (ma) for a redundancy allocation problem without component mixing (rapcm) in a series-parallel system when the redundancy strategy can be chosen for individual subsystems. majority of the solution methods for the general rapcm assume that the type of a redundancy strategy for each subsystem is pre-determined and known a prior...

A fresh look at the system analysis helped us in finding a new way of calculating the risks associated with the system. The author found that, due to the shortcomings of RPN, more researches needed to be done in this area to use RPNs as a new source of information for system risk analysis. It is the purpose of this article to investigate the fundamental concepts of failure modes and effects ana...

in the present paper, we develop a modified pseudospectral scheme for solving an optimal control problem which is governed by a switched dynamical system. many real-world processes such as chemical processes, automotive systems and manufacturing processes can be modeled as such systems. for this purpose, we replace the problem with an alternative optimal control problem in which the switching t...

introduction: health system performance assessment provides appropriate information about the status of health systems for governments and communities. therefore, in the recent decade, many countries have focused on performance assessment and reporting in order to develop methods and tools as a mean to help achieving health goals. the present study tries to design an indicator-based model (incl...

in this work the mathematical model of a spatial pattern inchemical and biological systems is investigated numerically. theproposed model considered as a nonlinear reaction-diffusionequation. a computational approach based on finite difference andrbf-collocation methods is conducted to solve the equation withrespect to the appropriate initial and boundary conditions. theability and robustness o...

to evaluate the interfacial morphology and the bond strength produced by the three-step, two-step and single-step bonding systems in primary teeth.occlusal surfaces of 72 extracted human deciduous teeth were ground to expose the dentin. the teeth were divided into four groups: (a) scotchbond multipurpose (3m, espe), (b) adh se (vivadent), (d) optibond all-in-one (kerr) and (e)futurabond nr (voc...

this article is a commentary of an overview on “medical tourism” submitted by lunt and marrion, which describes a framework for the study of the issues related to medical tourism. the commentary attempts to differentiate between the current interest in medical tourism and the time-honored and well-established treatment abroad from countries with underdeveloped health systems. the commentary als...

scheduling of production in flexible manufacturing systems (fmss) has been extensively investigated over the past years and it continues to attract the interest of both academic researchers and practitioners. the generation of new and modified production schedules is becoming a necessity in today’s complex manufacturing environment. genetic algorithms are used in this paper to obtain an initial...

today, students spend only 10 percent of their time in training centers and the major part of their time is spent in home, society and other places. however, significant events happen in this limited time. in addition to training and learning, they are prepared and educated to interact with society. education is an important issue in global educating and training systems. there are different ap...