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Search Results: 1 - 10 of 463262 matches for " Abd-Elrahman A. Alkafs "
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Enhancements in the Security Level for Wireless Sensor Network  [PDF]
Amr M. Kishk, Nagy W. Messiha, Nawal A. El-Fishawy, Abd-Elrahman A. Alkafs, Ahmed H. Madian
Journal of Information Security (JIS) , 2015, DOI: 10.4236/jis.2015.63022
Abstract: The trade off between the energy consumption and the quality of the received image should be considered as a main point in the techniques design in Wireless Sensor Network (WSN). This paper analyzes the performance of multiple image encryption algorithms with different approaches. And also, it introduces two proposed modulation techniques to enhance the performance of WSN. These two techniques merge both the image and the audio in one signal. The merging process enhances the energy consumption data rate. In addition, it removes the effectiveness of the jamming completely from both the reconstructed image and reconstructed audio signal at the receiver. So, the receiver will reconstruct the image without jamming effectiveness. The paper introduces a proposed audio encryption algorithm. The use of encryption algorithms for both image and audio signals with the merging process enhances the security level. Popular metrics are used to compare between these image encryption algorithms and also to show the benefits from these enhancements. The results show the preference of one of these image encryption algorithms to others. And also, the merging process enhances the bit rate to high level.
Building Extraction from High Resolution Space Images in High Density Residential Areas in the Great Cairo Region
Ibrahim F. Shaker,Amr Abd-Elrahman,Ahmed K. Abdel-Gawad,Mohamed A. Sherief
Remote Sensing , 2011, DOI: 10.3390/rs3040781
Abstract: This study evaluates a methodology for using IKONOS stereo imagery to determine the height and position of buildings in dense residential areas. The method was tested on three selected sites in an area of 8.5 km long by 7 km wide and covered by two overlapping (97% overlap) IKONOS images. The images were oriented using rational function models in addition to ground control points. Buildings were identified using an algorithm that utilized the Digital Surface Model (DSM) extracted from the images in addition to the image spectral properties. A digital terrain model was used with the DSM created from the IKONOS stereo imagery to compute building heights. Positional accuracy and building heights were evaluated using corner coordinates extracted from topographic maps and surveyed building heights. The results showed that the average building detection percentage for the test area was 82.6% with an average missing factor of 0.16. When the image rational polynomial coefficients were used to build the image model, results showed a horizontal accuracy of 2.42 and 2.39 m Root Mean Square Error (RMSE) for the easting and northing coordinates, respectively. When ground control points were used, the results improved to the sub-meter level. Differences between building heights extracted from the image model and the corresponding heights obtained through traditional ground surveying had a RMSE of 1.05 m.
Genomic Analysis and Classification of Exon and Intron Sequences Using DNA Numerical Mapping Techniques
Mohammed Abo-Zahhad,Sabah M. Ahmed,Shimaa A. Abd-Elrahman
International Journal of Information Technology and Computer Science , 2012,
Abstract: Using digital signal processing in genomic field is a key of solving most problems in this area such as prediction of gene locations in a genomic sequence and identifying the defect regions in DNA sequence. It is found that, using DSP is possible only if the symbol sequences are mapped into numbers. In literature many techniques have been developed for numerical representation of DNA sequences. They can be classified into two types, Fixed Mapping (FM) and Physico Chemical Property Based Mapping (PCPBM (. The open question is that, which one of these numerical representation techniques is to be used? The answer to this question needs understanding these numerical representations considering the fact that each mapping depends on a particular application. This paper explains this answer and introduces comparison between these techniques in terms of their precision in exon and intron classification. Simulations are carried out using short sequences of the human genome (GRch37/hg19). The final results indicate that the classification performance is a function of the numerical representation method.
Particle Swarm Optimization for Nano-Particles Extraction from Supporting Materials
Mohamed abd-ElRahman Abdou
International Journal of Image Processing , 2011,
Abstract: Evolutionary computation for image processing is an encouraging research area. Transmission electronmicroscopy (TEM) images when used to characterize metallic and non-metallic nano-particles (size,morphology, structure, or composition), need such advanced image processing algorithms. This paperpresents an efficient evolutionary computational method, particle swarm optimization (PSO), for automaticsegmentation of nano-particles. A threshold-based segmentation technique is applied, where imageentropy is attacked as a minimization problem to specify local and global thresholds. We are concernedwith reducing wrong characterization of nano-particles due to concentration of liquid solutions orsupporting material within the acquired image. The obtained results are compared with manualtechniques and with previous researches in this area.
Design and Development of a Multi-Purpose Low-Cost Hyperspectral Imaging System
Amr Abd-Elrahman,Roshan Pande-Chhetri,Gary Vallad
Remote Sensing , 2011, DOI: 10.3390/rs3030570
Abstract: Hyperspectral image analysis is gaining momentum in a wealth of natural resources and agricultural applications facilitated by the increased availability of low-cost imaging systems. In this study, we demonstrate the development of the Vegetation Mobile Mapping System (VMMS), a low-cost hyperspectral sensing system that is supported by consumer-grade digital camera(s). The system was developed using off-the-shelf imaging and navigation components mainly for ground-based applications. The system integrates a variety of components including timing and positioning GPS receivers and an Inertial Measurement Unit (IMU). The system was designed to be modular and interoperable allowing the imaging components to be used with different navigation systems. The technique used for synchronizing captured images with GPS time was presented. A relative radiometric calibration technique utilizing images of homogeneous targets to normalize pixel gain and offset parameters was used. An empirical spectral calibration method was used to assign wavelengths to image bands. Data acquisition parameters to achieve appropriate spatial coverage were presented. The system was tested in ground-based data collection and analysis experiments that included water quality and vegetation studies.
Hash Chain Links Resynchronization Methods in Video Streaming Security Performance Comparison
Emad Abd-Elrahman,Mohamed Boutabia,Hossam Afifi
Computer Science , 2015,
Abstract: Hash chains provide a secure and light way of security to data authentication including two aspects: Data Integrity and Data Origin Authentication. The real challenge of using the hash chains is how it could recover the synchronization state and continue keeping the hash link in case of packet loss? Based on the packet loss tolerance and some accepted delay of video delivery which are representing the permitted tolerance for heavy loaded applications, we propose different mechanisms for such synchronization recovery. Each mechanism is suitable to use according to the video use case and the low capabilities of end devices. This paper proposes comparative results between them based on the status of each one and its overhead. Then, we propose a hybrid technique based Redundancy Code (RC). This hybrid algorithm is simulated and compared analytically against the other techniques (SHHC, TSP, MLHC and TSS). Moreover, a global performance evaluation in terms of delay and overhead is conducted for all techniques.
Optimization of Quality of Experience through File Duplication in Video Sharing Servers
Emad Abd-Elrahman,Tarek Rekik,Hossam Afifi
Computer Science , 2015,
Abstract: Consumers of short videos on Internet can have a bad Quality of Experience QoE due to the long distance between the consumers and the servers that hosting the videos. We propose an optimization of the file allocation in telecommunication operators content sharing servers to improve the QoE through files duplication, thus bringing the files closer to the consumers. This optimization allows the network operator to set the level of QoE and to have control over the users access cost by setting a number of parameters. Two optimization methods are given and are followed by a comparison of their efficiency. Also, the hosting costs versus the gain of optimization are analytically discussed.
Alvarado score as an admission criterion in children with pain in right iliac fossa
Shreef Khalid,Waly Amira,Abd-Elrahman Sarhan,Abd Elhafez M
African Journal of Paediatric Surgery , 2010,
Abstract: Background: Acute appendicitis is an important differential diagnosis in children with pain in the right iliac fossa. Some patients have equivocal signs that make the diagnosis difficult. Many patients with suspected acute appendicitis are admitted for observation and finally discharged because they did not have appendicitis. We decided to design this study to investigate whether the Alvarado score could be used by emergency room doctors as a criterion for admission to hospital. Patients and Methods: This is a prospective study comprising 350 patients who attended the emergency department with suspected acute appendicitis in the period from May 2007 to April 2009. All patients were scored by Alvarado score in the emergency department before admission. The Alvarado score is based on three symptoms, three signs and two laboratory findings. The decision for admission and surgery was made independent of the score. The diagnosis of patients who underwent appendicectomy was confirmed by both operative findings and postoperative histopathology. Results: We studied the Alvarado scores of 350 patients who presented to the emergency department with pain in the right iliac fossa; their age ranged from 8 to 14 years; 182 patients (52%) operated with the aim to treat acute appendicitis, 168 patients (48%) were discharged without surgical intervention and advised to attend the out-patient clinic after 24 hours for re-evaluation. we have found that patients with a low Alvarado score (less than 6) did not have acute appendicitis. Conclusion: Patients with equivocal signs can present a diagnostic challenge and are very often admitted to the surgical department for observation. The Alvarado score can be used as a scoring system that help in taking the decision for admission of cases with suspected acute appendicitis especially by primary healthcare providers.
Modeling Relationships among 217 Fires Using Remote Sensing of Burn Severity in Southern Pine Forests
Sparkle L. Malone,Leda N. Kobziar,Christina L. Staudhammer,Amr Abd-Elrahman
Remote Sensing , 2011, DOI: 10.3390/rs3092005
Abstract: Pine flatwoods forests in the southeastern US have experienced severe wildfires over the past few decades, often attributed to fuel load build-up. These forest communities are fire dependent and require regular burning for ecosystem maintenance and health. Although prescribed fire has been used to reduce wildfire risk and maintain ecosystem integrity, managers are still working to reintroduce fire to long unburned areas. Common perception holds that reintroduction of fire in long unburned forests will produce severe fire effects, resulting in a reluctance to prescribe fire without first using expensive mechanical fuels reduction techniques. To inform prioritization and timing of future fire use, we apply remote sensing analysis to examine the set of conditions most likely to result in high burn severity effects, in relation to vegetation, years since the previous fire, and historical fire frequency. We analyze Landsat imagery-based differenced Normalized Burn Ratios (dNBR) to model the relationships between previous and future burn severity to better predict areas of potential high severity. Our results show that remote sensing techniques are useful for modeling the relationship between elevated risk of high burn severity and the amount of time between fires, the type of fire (wildfire or prescribed burn), and the historical frequency of fires in pine flatwoods forests.
Network Issues in Virtual Machine Migration
Hatem Ibn-Khedher,Emad Abd-Elrahman,Hossam Afifi,Jacky Forestier
Computer Science , 2015,
Abstract: Software Defined Networking (SDN) is based basically on three features: centralization of the control plane, programmability of network functions and traffic engineering. The network function migration poses interesting problems that we try to expose and solve in this paper. Content Distribution Network virtualization is presented as use case.
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