In this paper, we present an analytical traffic model for the Universal Mobile Telecommunication Systems (UMTS). In 3G networks we have dynamic capacity that depends on the interference levels in the covered area and the number of active users. This implies that the distance of the mobile user from the base station is also an important factor because of the signal fading. The first part of this paper is an algorithm written in c++ programming language that distributes users in different zones assuming that the cell area is virtually divided into Z zones depending on the number of users. The last part of this paper we build a mathematical model of a 3G cell using the above assumption , and to prove, that the product form holds in the case of two cells with uniform and non uniform traffic. By this result more complicated networks can be analyzed, to calculate the performance measures of the network.
WAEL S. ABUGHRES, MIKE E. WOODWARD(6-2006)

Abstract The DC motor drives one of the high performance drives that still in competition in industrial application, because of its high performance, robustness, and its lower cost compared with AC motor drives.Due to its majority applications, the separately excited DC motor driver is studied. In order to improve, three independent controller design using classical proportional - integral – derivative, linear quadratic regulator and artificial neural network are considered.The Performance of these controllers has been verified through simulation based on MATLAB/SIMULINK software tools. According to the obtained simulation results, it is found that, an artificial neural network can achieve a better transient and steady state response in comparing to the other two design method. Consequently, the superiority of ANN controller over conventional proportional - integral – derivative is demonstrated this shows the superiority of artificial neural network controller over conventional and linear quadratic regulator controllers.
.زينب إبراهيم علي (2014)

Abstract Ad-hoc networking is a concept in computer communications, which means that users wanting to communicate with each other form a temporary network, without any form of centralized administration. Each node participating in the network acts both as host and a router and must therefore be willing to forward packets for other nodes.In a multi-hop wireless packet network, a packet traverses more than one wireless link in traveling from its source to its destination. Such wireless networks have received considerable attention recently in the context of ad hoc networks. Ad-Hoc networks are self-organizing multi-hop wireless networks where not all links along the path of a packet can be activated simultaneously. Hence the performance of a higher level mechanism, such as congestion window or Transport Layer protocol (TCP) will depend crucially on how the links are scheduled for transmission. In multiple access networks, such as the IEEE802.11 wireless LAN, the scheduling of transmissions is done by the medium access control (MAC) protocol. This transmission scheduling is completely unaware of the needs of the TCP congestion window protocol. This thesis is concerned with the poor interaction between the TCP adaptive window protocol, the IEEE 802.11 MAC protocol, and the IEEE 802.11 Ad-Hoc routing protocol. Our thesis follow on the work done by the researchers K. Nahm and C. Kuo in the paper entitled “TCP over 802.11 Multihop networks issues and Performance Enhancement” [1]. Our contributions are two-fold. First we have repeated and confirmed the simulation results reported by K.Nahm and C.Kuo using NS-2 network simulator. Second we have introduced a simple modification in the 802.11 DSR routing protocol which reduces the unnecessary VI reroutings triggered by MAC packet collisions and enforces the TCP to enter the fast retransmit / fast recovery phase to quickly recover the packet loses. This modification has been simulated using NS-2 network simulator and from the results we have found that it provides a substantial improvement in TCP performance in the situations that we have considered in the simulation models
يحي الشارف المبروك (2009)