Mohammed El-Beltagy

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It is often the case in many problems in science and engineering that the analysis codes used are computationally very expensive. This can pose a serious impediment to the successful application of evolutionary optimization techniques. Metamodeling techniques present an enabling methodology for reducing the computational cost of such optimization problems.(More)
The use of statistical models to approximate detailed analysis codes for evolutionary optimization has attracted some attention [1-3]. However, those early methodologies do suffer from some limitations, the most serious of which being the extra tuning parameter introduceds. Also the question of when to include more data points to the approximation model(More)
The optimization of noisy or imprecisely specified functions is a common problem occurring in various applications. Models of physical systems can differ according to computational cost, accuracy and precision. In multilevel optimization, where different models of a system are used, there is a great benefit in understanding how many, fast evaluations of(More)
The ubiquity of the Internet poses serious concerns on the security of computer infrastructures and the integrity of sensitive data. Intrusion Detection Systems (IDS) aim at protecting networks and computers from malicious networkbased or host-based attacks. The underlying assumption of intrusion detection is an attack will noticeably affect system(More)
In this paper, we describe an application-level emulator for P2P systems with a special focus on high reproducibility. We achieve reproduciblity by taking control over the scheduling of concurrent events from the operating system. We accomplish that for interand intrapeer concurrency. The development of the system was driven by the need to enhance the(More)
In Multilevel Optimization there is usually a choice to be made between different models when carrying out design evaluations. The choice is between accurate / computationally expensive evaluations and approximate/ computational cheap ones. Here, a strategy is sought for selecting between different models during the search. The focus of the paper is on the(More)
In this paper we present an exploration of central coordination as a way of managing P2P live streaming overlays. The main point is to show the elements needed to construct a system with that approach. A key element in the feasibility of this approach is a near real-time optimization engine for peer selection. Peer organization in a way that enables high(More)
This paper deals with solving large instances of the Linear Sum Assignment Problems (LSAPs) under realtime constraints, using Graphical Processing Units (GPUs). The motivating scenario is an industrial application for P2P live streaming that is moderated by a central tracker that is periodically solving LSAP instances to optimize the connectivity of(More)