A denial of service attacks are usually employed to interrupt the system's activity by getting a large number of fake requests, which leads to slowing down and stopping information system or network operations. This paper outlines the basic principles of DDoS attacks, explains how DDoS attack works. The paper presents an experimental using OPNET simulation tool in which traffic from three different applications VoIP, FTP, and HTTP is used to make the practical model with a firewall shield to model and simulate DDoS over Internet. However, three scenarios have been developed to illustrate different aspects of the DDoS over networks. The results clearly demonstrate how firewalls can be configured to mitigate DDoS attacks
Azeddien M. Sllame, Reema A. Saed, Mariam Abojella Msaad(5-2021)

In this paper a brief introduction to the concept of quality of service has been given. However, it mainly focuses on the classification of routing algorithms based on a number of different criteria like: protocols, structure, technologies in use, etc. And it concludes with a presentation of a common problem facing routing protocols, namely routing loops, and explained the known solutions to that problem. arabic 6 English 52
Ibrahim Almerhag, Ali Ganoun(6-2018)

Deoxyribonucleic acid (DNA) micro-arrays present a powerful means of observing thousands of gene terms levels at the same time. They consist of high dimensional datasets, which challenge conventional clustering methods. The data’s high dimensionality calls for Self Organizing Maps (SOMs) to cluster DNA micro-array data. The DNA micro-array dataset are stored in huge biological databases for several purposes . The proposed methods are based on the idea of selecting a gene subset to distinguish all classes, it will be more effective to solve a multi-class problem, and we will propose a genetic programming (GP) based approach to analyze multi-class micro-array datasets. This biological dataset will be derived from multiple biological databases. The procedure responsible for extracting datasets called DNA-Aggregator. We will design a biological aggregator, which aggregates various datasets via DNA micro-array community-developed ontology based upon the concept of semantic Web for integrating and exchanging biological data. Our aggregator is composed of modules that retrieve the data from various biological databases. It will also enable queries by other applications to recognize the genes. The genes will be categorized in groups based on a classification method, which collects similar expression patterns. Using a clustering method such as k-mean is required either to discover the groups of similar objects from the biological database to characterize the underlying data distribution. arabic 10 English 60
Mariam Abojela Msaad, Zakaria Suliman Zubi(1-2010)