Sharif Digital Repository

In order to increase the network performance, to discover network security threats, to guarantee the quality of services, to simulate networks and develop new network protocols, network designers and operators need software tools to analyze the network traffic. The first step to do this analysis is network monitoring. This can be done by using various software and hardware tools.
In this research we developed a tool which analyzes the network traffic using appropriate statistical methods. The models which are analyzed in this application are: Poisson, Self-similar and Weibull. This application analyzes the network traffic based on this statistical models and calculates their parameters.... 

Distributed Denial of Service attacks are threats that target availability of network resources. One feature of this type of attacks is high volume of traffic or service request from huge number of illegitimate attackers that organize botnets together, which cause performance decrease of network. Nowadays, distinguishing huge number of legitimate users during Flash Crowd is one of the most challenging issues for network security experts. Most of proposed methods so far, did not have enough performance or were only applicable in short term, due to increasing attackers’ knowledge in mimicking legitimate users behavior. Methods based on extracting statistic features usually, have better... 

In this thesis we consider dynamical aspects of fractals. More precisely, answering questions like how heat diffuses on fractals and how does a material with fractal structure vibrates? To give an answer to these questions we need a PDE theory on fractals. Since fractals do not have smooth structures, defining differential operators like Laplacian is not possible from a classical viewpoint of analysis, to overcome such a difficulty we also need a theory of analysis on fractals. So as a good instance of analysis on fractals we first define Laplacian on Sierpinsky gasket and we try to extend the concept on other finitely ramified self-similar fractals. We also construct Dirichlet forms,...