المستودع الرقمي لـكلية الهندسة

—Predicting the groundwater level has recently become very important research topic especially with the rise of population density and consequently increasing the water demand. This paper uses the Random Forest and linear regression neural network models to predict the groundwater level of Wadi-Alshaty district in the South West part of Libya. The results are compared with that obtained using the hydrologic long-term forecasting graphical approach. One of the most important findings of this study is the effectiveness of the neural network models to investigate the fluctuation of the groundwater levels over time (20 years)
Amna Elhawil, Alarabi Naji, Malak Nuesry, Almabruk Sanossi(12-2021)

Building and infrastructure damages, such as tunnels, have become a more important issue because of the continuous expansion of rural and urban constructions. It is well-known that when high-strength concretes (HSCs) are exposed to high temperatures; it is more likely to experience explosive fire-induced spalling than conventional strength concrete. Spalling might result in catastrophic loss of life and damage to nearby critical infrastructure. The exposure of reinforcement bars to elevated temperature, decreased permeability, higher density, moisture transfer, and brittleness of the HSC contribute to spalling. The concrete on a structural member's surface may be violently ripped apart by a high and fast rising temperature during a fire. Despite being a non-combustible material, the physics-chemo-mechanical properties of concrete deteriorate when subject to high temperatures. The magnitude and duration of a fire in a concrete structure define the severity of the fire. The resistance to fire spalling of HSCs under different fire conditions, extremes, and tendencies must be explored urgently. Cementitious materials exhibited a positive impact as an alternative to cement in HSC because they are known as environmentally friendly concrete materials with superior fire-resistant properties. In addition, the inclusion of fibers as an additive reinforcement is adopted to prevent and mitigate fire spalling in HSCs. Therefore, the establishment of appropriate fire-safety measures is a fundamental requirement in building design to ensure the safety of its inhabitants. While the process of fire spalling for HSC during a fire has not yet been completely understood. For this reason, a critical literature study on recent developments in HSC fire-resistance performance should be conducted to determine the present fire spalling behavior of HSC in the event of high temperatures and/or a fire. This article systematically reviews the mechanisms, influential factors, and types of fire spalling. This literature also reviews the behavior, fire spalling modelling, and strategies to prevent spalling in HSC applications. Given the advantages of the research subject, several hotspot research topics for scientific investigations are also suggested to facilitate the widespread use of HSCs in advanced construction applications.
Hakim S. Abdelgader (5-2022)

Mobile terminals allow users to access services while on the move. This unique feature has driven the rapid growth in the mobile network industry, changing it from a new technology into a massive industry within less than two decades. In this thesis, we address admission control problems in a cellular wireless environment. The admission control is responsible for deciding whether an incoming call or connection can be accepted or not, which are based on the available codes . We provide an extensive survey of the existing admission control algorithms. The issues related to and the approaches for designing admission control in third generation(3G) cellular wireless networks are discussed. An admission control method considering the quality of service(QoS) requirements in wireless is presented along with 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 a mobile user from the base station, which is called Node B, is also an important factor because of the signal fading. The first part of this work is an algorithm written in C++ programming language that distributes users in different zones assuming that the cell area is divided into Z virtual zones, where Z depends on the number of users. In the rest of this thesis we present a simulation model for the Universal Mobile Telecommunication Systems(UMTS). For validation purposes, we have developed a much more detailed simulation of the system written in C language. The results of the mathematical model showed that, a product form equilibrium distribution holds in the case of two cells. Theses results are used to validate a simulation, and to show that the behaviour of the system is similar to that in the mathematical model. Once the product form of Jackson’s Theorem is known to hold, then it is possible to go to a more advanced stage to analyze the 3G network, and to get the performance measures, which will help in making decisions at the design stage of a network. To be more realistic, we used traffic distributions in the simulator, where a user can generate world wide web sessions(www), file transfer sessions, and Emails. These followed recommendations in the ETSI standard and further demonstrated the feasibility of the model.
Wael Saleh Abughres(7-2008)

The introduction of new services with different bandwidth requirements, e.g., data and multimedia, to cellular mobile radio networks makes many of the traditional mechanisms unusable or less efficient. The call admission control and the handover handling are the most sensitive issues to this extension. The performance of all services including the traditional voice and the new services can be dramatically effected if no appropriate schemes are used. In this research work, a new call admission and handover handling schemes for a cellular mobile network that offers two service types: voice and data is proposed. The data connections are assumed to be transmitted at different data rates, which are an integer multiple to that of one traffic channels, which are full speed(Cd1) & reduced peed(Cd2). In order to reduce the handover failure probability of data connections, the data mobile terminals (MT) are assumed to have the capability of transmitting at two different data rates. If the handover request can not be satisfied by the base station of the destination cell due to unavailable free traffic channels, the data mobile terminals tries with a lower data rate. The handover fails if the network is incapable on providing the minimum data rate at which the mobile terminal can transmit. The reduced data connection or data rate can be speeded up to full data rate or full speed as soon as enough bandwidth is available. The effect of different traffic and configuration parameters on the performance of the different models for two cell model with equal input traffic intensity, two cell model with different input traffic intensity, and two cell model with equal input traffic intensity considering the congestion rate for the highway model are studied as the models of this research. These models are built using MOSEL language (Modeling Specification and Evaluation Language). The results of investigating the mentioned models showed the effect of the handover, and speed of data on these different models.
W. ABUGHRES(1-2000)

In this paper, we present a simulation model for the Universal Mobile Telecommunication Systems (UMTS). For validation purposes, we have developed a much more detailed simulation of the system written in C language. The results of a previous mathematical model showed that, the product form holds in the case of two cells, and the objective of this paper is to prove the same result using simulation, and to show that the behavior of the system is similar to that in the previous work done in the mathematical model. Once the product form of Jackson's Theorem is Shown to hold, then it is possible to go to a more advanced stage to analyze the 3G network, and to get the performance measures, which will help in making decisions at the design stage
W. S. Abughres(3-2006)

In this paper, we present an algorithm to generate and distribute Z users in Z virtual zones. In3G networks we have dynamic capacity that depends on the interference levels in the covered areaand the number of active users. This implies that the distance of the mobile user from the basestation is also an important factor because of the signal fading. An algorithm is presented basedon the queuing traffic models for 3G cell written in c++ programming language that distributesusers in different zones assuming that the cell area is virtually divided into Z zones depending onthe number of users (1) (PDF) An algorithm for distributing users in virtual zones in a 3g cellular network. Available from: https://www.researchgate.net/publication/317949812_An_algorithm_for_distributing_users_in_virtual_zones_in_a_3g_cellular_network [accessed May 17 2022].
w. s. abughres, mikee. woodward(10-2006)

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)

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(3-2006)