This thesis deals with the communication network performance of the Automatic Vehicle Location (AVL) distributed database system. The Automatic Vehicle Location system is used to real-time track the movement of vehicles, traveling along a large geographical area. The full control of the movement of these vehicles requires the use of many communication systems such as Global Positioning system, Packet switching network and distributed database systems including vehicle position databases. The main goal of this thesis is to minimize the update response time in a real-time fully replicated distributed ...

The emerging field of wireless sensor networks combines sensing, computation, and communication into a single tiny device. Through advanced mesh networking protocols, these devices form a sea of connectivity that uses any possible communication path by hopping data from one node to another in search of its destination. While the capabilities of any single device are minimal, the collection of hundreds of sensors offers major new technological possibilities. Examples of usage scenarios for these devices are real-time tracking and security monitoring, issues that will be studied in this thesis. ...

Mobility attracts many developers and system designers; it will give us the ability to use our computers with no physical limitations with respect to connections. This thesis will try to introduce the main concepts that define mobile computing in our days. It will identify the challenges that face mobile computing and their impact on current developments in this area. Location management and how the cellular networks function is defined and described. We will conduct a comparison between protocols in location management with respect to network messages and database operations. In the IS-41 model ...

In this thesis, we investigate the use of neural networks for solving the Traveling Salesman Problem (TSP). First, we review the main elements of the theory of NP-completeness. Then, we explain what makes some problems computationally intractable. We review some heuristic approaches used to provide near-optimal solutions to NP-complete problems. Then, we introduce the topic of neural networks and describe some of the most popular neural network models. We pay a special attention to a recent model, named the Hybrid Neural Network model (HNN), used for solving optimization problems and the Hybrid ...

The HPG axis interacts with the Sertoli and Leydig cells to ensure the proper functioning of the male reproductive system. Environmental insults, which are becoming increasingly more common, affect the sensitive male reproductive system in harmful ways. Therefore, the aim of this thesis was to, analyze a network of the paternally imprinted infertility genes shared between the HPG axis and the Sertoli and Leydig cells. With this network in place, we aimed to develop a cell culture system that would allow the evaluation of the effects of certain environmental contaminants such as mycotoxins on ...

The allocation problem is known to be NP-Hard in the most general case where both the number of modules and the number of processors is arbitrary, and it is also Np-Complete in some of the restricted cases. Also, the general scheduling problem, where no restrictions are imposed on the interconnection structure between modules, on the modules processing time and on the number of parallel processors, is NP-Hard in the strong sense. Even under some restrictions, the scheduling problem is NP-Hard. In some other restricted cases, it is known to be NP-Complete. In this thesis, we first review fifty ...

This thesis uses the HITS algorithm as a basis to propose an interactive internet search engine. With the Web becoming a major source of information for many users, it became a necessity to be able to search the Web efficiently. The main problem resides with broad topic queries. These are queries for which a typical text-based search engine like AltaVista would return thousands of pages. A remedy for these situations was proposed by Kleinberg in his 1-IITS algorithm in which he uses the hyperlink structure of the Web as a major source of information about the contents of the Web. In this thesis, ...

Low-Ionization Nuclear Emission-Line Regions (LINERs) represent the low luminosity end of Active Galactic Nuclei (AGN). The main power source of LINERs is the subject of considerable debate in the scientific community today, despite the fact that some Liners show features of mass accretion into a super massive black hole (SMBH). Optical line-ratio diagrams are not conclusive diagnostic tools as they can be explained by different mechanisms, including shocks (Dopita et al. 1997[8]) and photoionization accompanied by outflow resembling accretion (Sabra et al. 2003[23]). This dissertation will ...

The aim of this thesis is to study the qualitative behavior of a specific non-linear Volterra integro-differential equation with finite delays by using Lyapunov's second method. The non-linear Volterra integro-differential equation is: $x'(t)=b(t)x(t-r_1)-\int_{t-r_2}^{t}a(t,s)g(x(s))ds,$ where $r_1$, $r_2$ are positive constants representing 2 finite delays, $t \geq 0$ and $a : \ [0,\infty) \times [-\tau, \infty) \rightarrow \R, \qquad \text{and} \qquad b : \ [0, \infty ) \rightarrow \R$ are two continuous functions. In the first part, we study the qualitative behavior of the constant ...