پديد آورنده :
ستاري، ارسلان
عنوان :
بررسي پديده ي ازدحام در شبكه هاي پيچيده
مقطع تحصيلي :
كارشناسي ارشد
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان، دانشكده فيزيك
صفحه شمار :
[نه]، 79ص.: مصور، جدول، نمودار
يادداشت :
ص.ع. به فارسي و انگليسي
استاد راهنما :
كيوان آقا بابايي ساماني
استاد مشاور :
فرهاد فضيله
تاريخ نمايه سازي :
15/12/90
استاد داور :
فرهاد شهبازي، مجتبي اعلائي
تاريخ ورود اطلاعات :
1396/10/12
چكيده فارسي :
به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي
چكيده انگليسي :
Congestion phenomena on complex networks Arsalan Sattari Email address sattari arsalan@gmail com Date of submission July 26 2011 Department of Physics Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Dr Keivan Aghababaei SamaniAbstract Huge increase in everything which operates on a network is called congestion Thesethings could be information packets in internet network or vehicles in road networks Congestioncan disorder the operation of complex networks which are transporting the information packets orparticles e g in Internet As a result the scientists study this phase transitive phenomenon by trafficmodels The first model which has been investigated in this thesis is a model that determines aparticular destination for every information packet that is created in the system and when it gets itsdestination it will be vanished The type of phase transition in this model is related to the routingrule of every node Routing rule is the way of finding the next node for hopping particles which canbe deterministic of probabilistic Then we investigate this model on a 2 D lattice and hierarchicalnetworks Then another model has been investigated for congestion phenomena and diffusion ofparticles which is basically about hopping of particles from every node to its neighboursstochastically The type of phase transition in this model is related to the structure of network andthe probability of rejecting particles A similar phase transitive behaviour has been observed like inthe previous model Basis of this model is defining two parameters q and which are respectivelythe probability of being empty and the probability of having number of particles greater than forthe queue length of every node By using of these two parameters and entering them into our basicrelations of the transition rate of increasing and decreasing in queue length of every node we willhave a transition rate in ensemble level Afterwards the three basic phases for every node aredefined free flow phase fickle phase and the congested phase which are respectively the phase inwhich the number of particles in every node are fixed approximately zero the phase that thenumber of particles are approximately and fluctuate around it and finally the phase that thenumber of particles are growing continuously Then this model is investigated on semi bipartitenetwork in which the generation of particles is only in peripheral nodes By using these threephases for central and peripheral nodes nine different phases are defined for this system Then thetype of transition between different phases has been explained which is the origin of hysteresis inthis process Finally all of these predictions are verified by computational simulation Key words complex networks congestion phenomena phase transition
استاد راهنما :
كيوان آقا بابايي ساماني
استاد مشاور :
فرهاد فضيله
استاد داور :
فرهاد شهبازي، مجتبي اعلائي
