Magdy Koutb

An optimized Kerberos authentication protocol

This paper will introduce simple modifications to the database of the widely deployed Kerberos authentication protocol. The principles long-term secret key will be independent of the user password with the aim to overcome the weak passwords chosen by the network principal that are susceptible to password guessing attacks, the main drawback of the Kerberos protocol. Instead, the Kerberos Distribution Center will save a profile for every instance in the realm that it mange and the secret key will be generated based on that profile. This profile will be hashed and then, the output digest will be encrypted to generate the secret key. Besides, the lifetime of the secret key will be controlled using the system lifetime. We will use Triple-Des as an encryption algorithm, SHA-256 as a hashing algorithm, and Blum Blum Shub as a random number generator algorithm.

Maximum power control of hybrid wind-diesel-storage system

Optimum wind energy extraction is a very important economical target. This paper is concerned with the development of a robust controller for the wind turbines in hybrid wind-diesel storage system (HWDSS). The proposed algorithm, which is based on fuzzy linear matrix equalities (FLME), maximizes the power coefficient for a fixed pitch. Moreover, it reduces the voltage ripple and stabilizes the system over a wide range of wind speed variations. The control scheme is tested for different profiles of wind speed pattern and provides satisfactory results.

Building and Evaluating Adaptive Web Pages

Each year the number of consumers and the variety of their interests increase. As a result, providers are seeking ways to infer the customers interests and to adapt their websites to make the content of interest more easily accessible. Assume that past navigation behaviour as an indicator of the users interests. Then, the records of this behaviour, kept in the web-server logs, can be mined to extract the users interests. On this principal, recommendations can be generated, to help old and new websites visitors to find the information about their interest faster.

Advanced control technique application in U-tube steam generator of nuclear power station

A water level control system for a nuclear steam generator (SG) is proposed. A method to improve the performance of nuclear steam generator in nuclear power station is introduced. Combination of genetic algorithm (GA) technique and fuzzy logic control is carried out. The optimal parameters of fuzzy logic controller are achieved. These parameters include; the membership functions of water level error and changes water level error, the rule base, and the input scaling gains. Steam generator model is implemented using MATLAB/SIMULINK. The optimal controller was applied to control the water level of nuclear SG and its compared with conventional controller. Simulation results indicate that the optimal fuzzy controller greatly improves the performance of nuclear SG. Moreover the proposed controller is robust to any disturbance related to sudden changes in steam flow rate and water level. Moreover the proposed controller is robust to any disturbance related to load variations.

Evolutionary computation applictaion in power level control of nuclear power station

The problem of controlling the output power of the nuclear power station (NPS) is considered. Automatic power stabilization control is the desired goal for any nuclear reactor operation policy, especially, NPS. In this paper the conventional controllers like Proportional-derivative (PD) were designed for the power control system of the NPS. Tuning techniques such as the Ziegler-Nichols and Cohen-Coon tuning formulae, but is difficult to do that for nonlinear and time varying systems. A method to improve the performance of proposed controller is introduced. The objective is to tune proportional gain and differential gain of proposed controller. Combinations of GA and PSO are carried out. The optimal parameters of desired controller are achieved. The PWR is selected as NPS, and it was simulated using MATLAB/SIMULINK package. Simulation results indicate that the designed controller greatly improves the performance of NPS.

On-Line Distributed Neurocontrollers Based on Microcontrollers

This paper concerns the development of a practical distributed on-line neurocontrollers for temperature processes using microcontrollers. The suggested controllers are composed of a network of microcontrollers that are coordinated by a supervisor microcontroller interfaced with the user via LCD and remote control system. This distributed control system supports serial data communication with PC. Implementation of the designed distributed control system to control multi-furnace has carried out. The system performance is considered in the cases of disturbance free and disturbance present. Experimental results illustrations of the designed system are indicated