Sharif Digital Repository

Dynamic design of underground structures is complicated and difficult. Although underground structures are less vulnerable than surface structures, dynamic analysis of these structures during their design process is necessary. In this project, numerical studying of fault effect on underground structures and its dynamic responses, focusing on tunnel Shebli was conducted. Two-dimensional model utilizing UDEC software which is based on descrete elements method was used for this analysis. Time history of Manjil Earthquake using horizontal component of ground acceleration which is propagated toward earth surface was applied to models as a shear wave with respect to depth and type of rock. To... 

Exact Renormalization Equations (ERGE) are powerful non-perturbative tools to study the dynamics of Quantum Field theories, with respect to the change of energy. Putting cut-off on momentums of the system, is the specific regularization that is used to obtain ERGEs. This regularization breaks the gauge symmetry in the case of gauge theories. So the symmetry will be lost through the energy flow as well.Finding a gauge symmetry for a regularized system is the aim of this research. Also we have investigated the related ERGEs and the behavior of symmetry through the flow  

Most of the real-world systems can be modeled as closed loop systems which are made up of a LTI subsystem in the forward path and a memoryless nonlinear subsystem in the feedback path. Such systems are called “Lur’e systems”, the name of the first who introduced these systems. Because of the generality and the wide applicability of this type of systems, studying the stability of them has been notable and interesting to many scientists for a long time. Meanwhile, in recent decades, many scientists in physics and engineering sciences have been interested in applications of the fractional order systems and as a result focused on studying the features of the fractional order systems. An... 

Increasingenergy requirements, limitedfossil resources, environmental pollutioncaused byfossilfuels, global warmingand other factorshaveled tothe approach ofscience and technologyfor renewable energies. One of the renewable energies is the energy relevant to ocean currents that is mainlydue to theinteractionbetween thetidalattraction ofthe moon,sun andearth. In our country,due tothehigh tideon the southern coast, there isgood potentialto use thistype of energy. One of themost favorableareasformarinecurrentpower plantslocated inthe northern part ofthe islandof Qeshmchannel.In this thesis,to exploitthis potential, the newidea ofHunter tidalturbine was investigated,because...