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Riyadh, Saudi Arabia

Taha Z.Q.,Imam University | Farraj A.K.,Texas A&M University
Wireless Personal Communications

Space-time coding can achieve transmit diversity and power gain over spatially uncoded systems without sacrificing bandwidth. There are various approaches in coding structures, including space-time block codes. A class of space-time block codes namely quasi-orthogonal space-time block codes can achieve the full rate, but the conventional decoders of these codes experience interference terms resulting from neighboring signals during signal detection. The presence of the interference terms causes an increase in the decoder complexity and a decrease in the performance gain. In this article, we propose a modification to the conventional coding/decoding scheme that will improve performance, reduce decoding complexity, and improve robustness against channel estimation errors as well. © 2012 Springer Science+Business Media, LLC. Source

Mundher M.,University of Technology Malaysia | Muhamad D.,University of Technology Malaysia | Rehman A.,Salman bin Abdul Aziz University | Saba T.,Prince Sultan University | Kausar F.,Imam University
Applied Mathematics and Information Sciences

This paper presents digital images watermarking approach to sustain the ownership and true authentication. To secure intellectual belongings of images, audio and videos, watermark W is converted into a sequence of bits and in order to encrypt the watermark, sequence of size R is selected randomly. Additionally, a pseudo random number is generated to calculate pixels for selection key generation. Finally, 2-level discrete slanlet transform (DST) on the host image is applied to divide it into Red, Green and Blue channels. The results thus produced from proposed methodology exhibit robustness against the existing state of the art. Further, proposed approach effectively extract watermark in the absence of the original images. © 2014 NSP Natural Sciences Publishing Cor. Source

Azmi A.M.,King Saud University | Al-Thanyyan S.,Imam University
Computer Speech and Language

Automatic text summarization is an essential tool in this era of information overloading. In this paper we present an automatic extractive Arabic text summarization system where the user can cap the size of the final summary. It is a direct system where no machine learning is involved. We use a two pass algorithm where in pass one, we produce a primary summary using Rhetorical Structure Theory (RST); this is followed by the second pass where we assign a score to each of the sentences in the primary summary. These scores will help us in generating the final summary. For the final output, sentences are selected with an objective of maximizing the overall score of the summary whose size should not exceed the user selected limit. We used Rouge to evaluate our system generated summaries of various lengths against those done by a (human) news editorial professional. Experiments on sample texts show our system to outperform some of the existing Arabic summarization systems including those that require machine learning. © 2012 Elsevier Ltd. All rights reserved. Source

Taoufiki M.,Imam University
3rd International Conference on Digital Information Processing and Communications, ICDIPC 2013

In this paper, we show that the watermarking method based on sources separation can be easily detected and destroyed. Indeed, the previous method is based on a simple linear mixture between the watermarks (signatures) and the original signal (the signal to be protected) with grossly different proportions. In this paper, we propose an attack based on blind sources separation that has the ability to extract the signatures independently from the original signal using just one observed mixture. © 2013 SDIWC. Source

Al-Humoud S.O.,Imam University | Mackenzie L.M.,University of Glasgow
Journal of Computers (Finland)

An interesting application of wireless MANETs that is emerging with a high potential for research and development is the inter-vehicle communication where nodes collect and distribute traffic information while moving in urban areas. Broadcasting is a key component to vehicular communication with the aim of high coverage and low medium consumption. Existing broadcasting schemes, however, result in redundancy and medium contention. In this paper a broadcasting scheme with intelligent neighbourhood sensing is produced and tested in two Vehicle Ad Hoc Network (VANET) contexts. Simulation results show that our scheme reduces the amount of unneeded transmissions through the medium even under high density with high traffic loads while maintaining comparable network coverage. © 2013 ACADEMY PUBLISHER. Source

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