Mohammad Hussein

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Execution plans generated by traditional optimizers for large scale distributed queries can be sub-optimal because: the estimations are inaccurate, the data are unavailable and the execution environment is unstable. To deal with the sub-optimality, we propose to execute each relational operator of an execution plan by a mobile agent. A mobile agent can(More)
Quality assurance (QA) for intensity- and volumetric-modulated radiotherapy (IMRT and VMAT) has evolved substantially. In recent years, various commercial 2D and 3D ionization chamber or diode detector arrays have become available, allowing for absolute verification with near real time results, allowing for streamlined QA. However, detector arrays are(More)
BACKGROUND Atherosclerosis is an inflammatory disease of the blood vessel wall, characterized in early stages by endothelial dysfunction, recruitment and activation of monocyte/macrophages. Glimepiride is one of the third generation sulphonylurea drugs, useful for control of diabetes mellitus type two and it may exert anti inflammatory activity, by(More)
Matrix inversion is a common function found in many algorithms used in wireless communication systems. As Field Programmable Gate Array (FPGA) become an increasingly attractive platform for wireless communication, it is important to understand the tradeoffs in designing a matrix inversion core on an FPGA. In this paper, a configurable Field Programmable(More)
The query processing in large scale distributed mediations systems raises new problems and presents real challenges: efficiency of access, communication, confidentiality of access, availability of data, memory allocation. In this paper, we propose an execution model based on mobile agents for the distributed dynamic query optimization. In this model, each(More)
In the large scale distributed environment, the query optimization presents new problems because of the data unavailability, the estimations inaccuracies and environment instability. In this paper, we address the sub-optimality of executions plans caused by these problems. We propose to extend the join algorithms based on mobile agents in order to correct(More)
The data warehouse holds information management and turns it into meaningful management information, from which, very interesting patterns can be discovered by applying knowledge discovery process. As the update of the Data Warehouse is not too frequent, it is possible to improve query performance while storing the data retrieved by them in a cache.(More)
—The problem with MOLAP is that large tables should be loaded in main memory, which can slow the system, even saturate the memory. In this work, we present a new compression method, called BTC, for multidimensional data warehouses. Several methods have been proposed in the literature that can compress the data such as the Bitmap method. The main purpose of(More)
In the context of heterogeneous and distributed data sources in large scale, the traditional optimizers generate execution plans can be sub-optimal because: the estimations are inaccurate, the unavailability of data and the execution environment is unstable. To deal with the sub-optimality of an execution plan, an approach consists to execute each(More)
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