Hassan Ismail Abdalla

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Users of distributed database systems often observe performance problems such as unexpectedly low throughput or high latency. Determining the cause of the performance problems can be very hard task. Bottlenecks can occur in any of the components through which the data flows: the applications, the operating systems, the network interfaces and hardware.(More)
Distributed processing is an effective way to improve performance of database systems. Therefore, fragmentation and proper allocation of fragments across various sites of the network is considered as a key research area in distributed database environment. However, the issue of allocating fragments to the most appropriate sites is not an easy task to(More)
The problem of allocating data fragments to the most appropriate sites of a distributed database systems is a difficult one to solve, however, most available approaches rely on heuristic techniques usually based on mathematical programming and formulations. The approach adopted in this paper contributes in determining best possible allocation of a data(More)
Feature-based approaches play an important role and are widely applied in extractive summarization. In this paper, we use particle swarm optimization (PSO) to evaluate the effectiveness of different state-of-the-art features used to summarize Arabic text. The PSO is trained on the Essex Arabic summaries corpus data to determine the best particle that(More)
Among the techniques that the distributed database designer considers for performance improvement are fragmentation, replication and allocation techniques. Fragmentation is the process of dividing a relation into two or more relations called fragments. Usually two fragmentation techniques are considered, these are: vertical and horizontal fragmentation. A(More)