Application layer Distributed denial of service (DDoS) attack is a continuous threat to the World Wide Web. Derived from the lower layers, new application-layer-based DDoS attacks utilizing legitimate HTTP requests over the victim resources are more unavailable. This issue may be more critical when such attacks mimic or occur during the flash crowd event of popular websites. Our technique presents the detection of such new DDoS attacks, a novel scheme based on document popularity and also Access Matrix is defined to capture the spatial-temporal patterns of a normal flash crowd. A novel attack detector based on hidden semi-Markov model is proposed to describe the dynamics of Access Matrix and to detect such attacks. The entropy of document popularity fitting to the model is used to detect the potential DDoS attacks in application-layer. This paper analyses the drawbacks of existing attack detection systems and proposes a new and efficient application layer distributed denial approach.

This electrical engineering project is to design and improve electrical traditional mogogo as energy efficient, power consumption reliable and automatic controllable. This efficient mogogo has a great hope for solving the energy crisis in our nation as well as to reduce the monthly electric bill payment for individual users. The power to be reduced by this project is about ¾ of the power of the excited mogogo. In addition to this it can prepare injera by automated microcontroller based control. In achieving this project goals material selection is the key factor, which we considered the most.