introduction: the mobile phone is viewed as an important communication tool and has become an integral part of the iranian society and they are increasingly using the mobile phone rather than the fixed line telephone as a way to keep in touch with their family, friends, colleagues and business associates. today, mobile phones are equipped with other features that allow further communication and...

The dynamics of chemical reaction networks often takes place on widely differing time scales--from the order of nanoseconds to the order of several days. This is particularly true for gene regulatory networks, which are modeled by chemical kinetics. Multiple time scales in mathematical models often lead to serious computational difficulties, such as numerical stiffness in the case of differenti...

In the present study, some perturbation methods are applied to Duffing equations having a displacement time-delayed variable to study the stability of such systems. Two approaches are considered to analyze Duffing oscillator having a strong delayed variable. The homotopy perturbation method is applied through the frequency analysis and nonlinear frequency is formulated as a function of all the ...

objectives: multiple sclerosis is the most prevalent central nervous system diseases thatdue to being chronic, frequent recurrence, uncertainty about its progress, and disability, can lead to various distresses as well as demoralization . rehabilitation method based on cognitive-existential therapy is an integratedapproach which can help to decrease demoralization syndrome in these patients. th...

A neuron embedded in an intact brain, unlike an isolated neuron, participates in network activity at various spatial resolutions. Such multiple scale spatial dynamics is potentially reflected in multiple time scales of temporal dynamics. We identify such multiple dynamical time scales of the inter-spike interval (ISI) fluctuations of neurons of waking/sleeping rats by means of multiscale analys...